2008-01-18 23:58:57 +01:00
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Commit Limiting
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~~~~~~~~~~~~~~~
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Besides specifying a range of commits that should be listed using the
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special notations explained in the description, additional commit
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2012-09-14 03:54:30 +02:00
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limiting may be applied.
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Using more options generally further limits the output (e.g.
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`--since=<date1>` limits to commits newer than `<date1>`, and using it
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with `--grep=<pattern>` further limits to commits whose log message
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has a line that matches `<pattern>`), unless otherwise noted.
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Note that these are applied before commit
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ordering and formatting options, such as `--reverse`.
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2008-01-18 23:58:57 +01:00
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2012-09-06 16:28:03 +02:00
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-<number>::
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-n <number>::
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2009-04-07 19:24:33 +02:00
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--max-count=<number>::
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2011-03-08 09:31:24 +01:00
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Limit the number of commits to output.
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2008-01-18 23:58:57 +01:00
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2009-04-07 19:24:33 +02:00
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--skip=<number>::
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2008-01-18 23:58:57 +01:00
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Skip 'number' commits before starting to show the commit output.
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2009-04-07 19:24:33 +02:00
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--since=<date>::
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--after=<date>::
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2008-01-18 23:58:57 +01:00
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Show commits more recent than a specific date.
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2022-04-23 14:59:57 +02:00
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--since-as-filter=<date>::
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Show all commits more recent than a specific date. This visits
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all commits in the range, rather than stopping at the first commit which
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is older than a specific date.
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2009-04-07 19:24:33 +02:00
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--until=<date>::
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--before=<date>::
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2008-01-18 23:58:57 +01:00
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Show commits older than a specific date.
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2008-03-02 15:11:35 +01:00
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ifdef::git-rev-list[]
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2009-04-07 19:24:33 +02:00
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--max-age=<timestamp>::
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--min-age=<timestamp>::
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2008-01-18 23:58:57 +01:00
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Limit the commits output to specified time range.
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2008-03-02 15:11:35 +01:00
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endif::git-rev-list[]
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2008-01-18 23:58:57 +01:00
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2009-04-07 19:24:33 +02:00
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--author=<pattern>::
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--committer=<pattern>::
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2008-01-18 23:58:57 +01:00
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Limit the commits output to ones with author/committer
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2012-09-14 03:54:30 +02:00
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header lines that match the specified pattern (regular
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expression). With more than one `--author=<pattern>`,
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commits whose author matches any of the given patterns are
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chosen (similarly for multiple `--committer=<pattern>`).
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2008-01-18 23:58:57 +01:00
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2012-09-29 06:41:28 +02:00
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--grep-reflog=<pattern>::
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Limit the commits output to ones with reflog entries that
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match the specified pattern (regular expression). With
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more than one `--grep-reflog`, commits whose reflog message
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2012-09-29 20:59:52 +02:00
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matches any of the given patterns are chosen. It is an
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error to use this option unless `--walk-reflogs` is in use.
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2012-09-29 06:41:28 +02:00
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2009-04-07 19:24:33 +02:00
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--grep=<pattern>::
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2008-01-18 23:58:57 +01:00
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Limit the commits output to ones with log message that
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2012-09-14 03:54:30 +02:00
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matches the specified pattern (regular expression). With
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more than one `--grep=<pattern>`, commits whose message
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matches any of the given patterns are chosen (but see
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`--all-match`).
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2015-08-23 19:56:40 +02:00
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ifndef::git-rev-list[]
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2012-09-29 06:41:29 +02:00
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+
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2019-11-20 00:55:32 +01:00
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When `--notes` is in effect, the message from the notes is
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2015-04-17 16:28:56 +02:00
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matched as if it were part of the log message.
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2015-08-23 19:56:40 +02:00
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endif::git-rev-list[]
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2008-01-18 23:58:57 +01:00
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2008-11-02 19:32:46 +01:00
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--all-match::
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2013-11-15 02:34:01 +01:00
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Limit the commits output to ones that match all given `--grep`,
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2012-09-14 03:54:30 +02:00
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instead of ones that match at least one.
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2008-11-02 19:32:46 +01:00
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log: teach --invert-grep option
"git log --grep=<string>" shows only commits with messages that
match the given string, but sometimes it is useful to be able to
show only commits that do *not* have certain messages (e.g. "show
me ones that are not FIXUP commits").
Originally, we had the invert-grep flag in grep_opt, but because
"git grep --invert-grep" does not make sense except in conjunction
with "--files-with-matches", which is already covered by
"--files-without-matches", it was moved it to revisions structure.
To have the flag there expresses the function to the feature better.
When the newly inserted two tests run, the history would have commits
with messages "initial", "second", "third", "fourth", "fifth", "sixth"
and "Second", committed in this order. The commits that does not match
either "th" or "Sec" is "second" and "initial". For the case insensitive
case only "initial" matches.
Signed-off-by: Christoph Junghans <ottxor@gentoo.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-01-13 02:33:32 +01:00
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--invert-grep::
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Limit the commits output to ones with log message that do not
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match the pattern specified with `--grep=<pattern>`.
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2008-06-08 03:36:09 +02:00
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-i::
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--regexp-ignore-case::
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2013-11-15 02:34:02 +01:00
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Match the regular expression limiting patterns without regard to letter
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case.
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2008-01-18 23:58:57 +01:00
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2012-10-04 00:01:34 +02:00
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--basic-regexp::
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Consider the limiting patterns to be basic regular expressions;
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this is the default.
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2008-06-08 03:36:09 +02:00
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-E::
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--extended-regexp::
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2008-01-18 23:58:57 +01:00
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Consider the limiting patterns to be extended regular expressions
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instead of the default basic regular expressions.
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2008-06-08 03:36:09 +02:00
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-F::
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--fixed-strings::
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2008-02-26 13:22:05 +01:00
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Consider the limiting patterns to be fixed strings (don't interpret
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pattern as a regular expression).
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2017-05-25 22:05:24 +02:00
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-P::
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2012-10-04 00:01:34 +02:00
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--perl-regexp::
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2017-05-20 23:42:05 +02:00
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Consider the limiting patterns to be Perl-compatible regular
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expressions.
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+
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Support for these types of regular expressions is an optional
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compile-time dependency. If Git wasn't compiled with support for them
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providing this option will cause it to die.
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2012-10-04 00:01:34 +02:00
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2008-01-18 23:58:57 +01:00
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--remove-empty::
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Stop when a given path disappears from the tree.
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2009-07-13 17:11:44 +02:00
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--merges::
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2011-03-23 10:38:51 +01:00
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Print only merge commits. This is exactly the same as `--min-parents=2`.
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2009-07-13 17:11:44 +02:00
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2008-01-18 23:58:57 +01:00
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--no-merges::
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2011-03-23 10:38:51 +01:00
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Do not print commits with more than one parent. This is
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exactly the same as `--max-parents=1`.
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--min-parents=<number>::
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--max-parents=<number>::
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--no-min-parents::
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--no-max-parents::
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2013-08-02 20:40:07 +02:00
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Show only commits which have at least (or at most) that many parent
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2011-03-23 10:38:51 +01:00
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commits. In particular, `--max-parents=1` is the same as `--no-merges`,
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`--min-parents=2` is the same as `--merges`. `--max-parents=0`
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gives all root commits and `--min-parents=3` all octopus merges.
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+
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`--no-min-parents` and `--no-max-parents` reset these limits (to no limit)
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again. Equivalent forms are `--min-parents=0` (any commit has 0 or more
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parents) and `--max-parents=-1` (negative numbers denote no upper limit).
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2008-01-18 23:58:57 +01:00
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--first-parent::
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git-rev-list: add --exclude-first-parent-only flag
It is useful to know when a branch first diverged in history
from some integration branch in order to be able to enumerate
the user's local changes. However, these local changes can
include arbitrary merges, so it is necessary to ignore this
merge structure when finding the divergence point.
In order to do this, teach the "rev-list" family to accept
"--exclude-first-parent-only", which restricts the traversal
of excluded commits to only follow first parent links.
-A-----E-F-G--main
\ / /
B-C-D--topic
In this example, the goal is to return the set {B, C, D} which
represents a topic branch that has been merged into main branch.
`git rev-list topic ^main` will end up returning no commits
since excluding main will end up traversing the commits on topic
as well. `git rev-list --exclude-first-parent-only topic ^main`
however will return {B, C, D} as desired.
Add docs for the new flag, and clarify the doc for --first-parent
to indicate that it applies to traversing the set of included
commits only.
Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-11 22:39:41 +01:00
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When finding commits to include, follow only the first
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parent commit upon seeing a merge commit. This option
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can give a better overview when viewing the evolution of
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a particular topic branch, because merges into a topic
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branch tend to be only about adjusting to updated upstream
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from time to time, and this option allows you to ignore
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the individual commits brought in to your history by such
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a merge.
|
2020-12-21 16:19:58 +01:00
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ifdef::git-log[]
|
2021-02-17 20:56:04 +01:00
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+
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This option also changes default diff format for merge commits
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to `first-parent`, see `--diff-merges=first-parent` for details.
|
2020-12-21 16:19:58 +01:00
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endif::git-log[]
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|
|
git-rev-list: add --exclude-first-parent-only flag
It is useful to know when a branch first diverged in history
from some integration branch in order to be able to enumerate
the user's local changes. However, these local changes can
include arbitrary merges, so it is necessary to ignore this
merge structure when finding the divergence point.
In order to do this, teach the "rev-list" family to accept
"--exclude-first-parent-only", which restricts the traversal
of excluded commits to only follow first parent links.
-A-----E-F-G--main
\ / /
B-C-D--topic
In this example, the goal is to return the set {B, C, D} which
represents a topic branch that has been merged into main branch.
`git rev-list topic ^main` will end up returning no commits
since excluding main will end up traversing the commits on topic
as well. `git rev-list --exclude-first-parent-only topic ^main`
however will return {B, C, D} as desired.
Add docs for the new flag, and clarify the doc for --first-parent
to indicate that it applies to traversing the set of included
commits only.
Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-11 22:39:41 +01:00
|
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--exclude-first-parent-only::
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When finding commits to exclude (with a '{caret}'), follow only
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the first parent commit upon seeing a merge commit.
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This can be used to find the set of changes in a topic branch
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from the point where it diverged from the remote branch, given
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that arbitrary merges can be valid topic branch changes.
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|
2008-01-18 23:58:57 +01:00
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--not::
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Reverses the meaning of the '{caret}' prefix (or lack thereof)
|
2013-11-15 02:34:01 +01:00
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for all following revision specifiers, up to the next `--not`.
|
2008-01-18 23:58:57 +01:00
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--all::
|
2017-02-08 07:06:41 +01:00
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Pretend as if all the refs in `refs/`, along with `HEAD`, are
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listed on the command line as '<commit>'.
|
2008-11-17 22:03:59 +01:00
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2010-10-08 19:31:15 +02:00
|
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--branches[=<pattern>]::
|
docs: don't talk about $GIT_DIR/refs/ everywhere
It is misleading to say that we pull refs from $GIT_DIR/refs/*, because we
may also consult the packed refs mechanism. These days we tend to treat
the "refs hierarchy" as more of an abstract namespace that happens to be
represented as $GIT_DIR/refs. At best, this is a minor inaccuracy, but at
worst it can confuse users who then look in $GIT_DIR/refs and find that it
is missing some of the refs they expected to see.
This patch drops most uses of "$GIT_DIR/refs/*", changing them into just
"refs/*", under the assumption that users can handle the concept of an
abstract refs namespace. There are a few things to note:
- most cases just dropped the $GIT_DIR/ portion. But for cases where
that left _just_ the word "refs", I changed it to "refs/" to help
indicate that it was a hierarchy. I didn't do the same for longer
paths (e.g., "refs/heads" remained, instead of becoming
"refs/heads/").
- in some cases, no change was made, as the text was explicitly about
unpacked refs (e.g., the discussion in git-pack-refs).
- In some cases it made sense instead to note the existence of packed
refs (e.g., in check-ref-format and rev-parse).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-18 02:16:20 +01:00
|
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|
Pretend as if all the refs in `refs/heads` are listed
|
2010-10-08 19:31:15 +02:00
|
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|
on the command line as '<commit>'. If '<pattern>' is given, limit
|
2010-01-20 10:48:26 +01:00
|
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|
branches to ones matching given shell glob. If pattern lacks '?',
|
2012-02-28 16:35:48 +01:00
|
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|
'{asterisk}', or '[', '/{asterisk}' at the end is implied.
|
2008-11-17 22:03:59 +01:00
|
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|
2010-10-08 19:31:15 +02:00
|
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|
--tags[=<pattern>]::
|
docs: don't talk about $GIT_DIR/refs/ everywhere
It is misleading to say that we pull refs from $GIT_DIR/refs/*, because we
may also consult the packed refs mechanism. These days we tend to treat
the "refs hierarchy" as more of an abstract namespace that happens to be
represented as $GIT_DIR/refs. At best, this is a minor inaccuracy, but at
worst it can confuse users who then look in $GIT_DIR/refs and find that it
is missing some of the refs they expected to see.
This patch drops most uses of "$GIT_DIR/refs/*", changing them into just
"refs/*", under the assumption that users can handle the concept of an
abstract refs namespace. There are a few things to note:
- most cases just dropped the $GIT_DIR/ portion. But for cases where
that left _just_ the word "refs", I changed it to "refs/" to help
indicate that it was a hierarchy. I didn't do the same for longer
paths (e.g., "refs/heads" remained, instead of becoming
"refs/heads/").
- in some cases, no change was made, as the text was explicitly about
unpacked refs (e.g., the discussion in git-pack-refs).
- In some cases it made sense instead to note the existence of packed
refs (e.g., in check-ref-format and rev-parse).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-18 02:16:20 +01:00
|
|
|
Pretend as if all the refs in `refs/tags` are listed
|
2010-10-08 19:31:15 +02:00
|
|
|
on the command line as '<commit>'. If '<pattern>' is given, limit
|
2012-02-28 16:35:48 +01:00
|
|
|
tags to ones matching given shell glob. If pattern lacks '?', '{asterisk}',
|
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|
|
or '[', '/{asterisk}' at the end is implied.
|
2008-11-17 22:03:59 +01:00
|
|
|
|
2010-10-08 19:31:15 +02:00
|
|
|
--remotes[=<pattern>]::
|
docs: don't talk about $GIT_DIR/refs/ everywhere
It is misleading to say that we pull refs from $GIT_DIR/refs/*, because we
may also consult the packed refs mechanism. These days we tend to treat
the "refs hierarchy" as more of an abstract namespace that happens to be
represented as $GIT_DIR/refs. At best, this is a minor inaccuracy, but at
worst it can confuse users who then look in $GIT_DIR/refs and find that it
is missing some of the refs they expected to see.
This patch drops most uses of "$GIT_DIR/refs/*", changing them into just
"refs/*", under the assumption that users can handle the concept of an
abstract refs namespace. There are a few things to note:
- most cases just dropped the $GIT_DIR/ portion. But for cases where
that left _just_ the word "refs", I changed it to "refs/" to help
indicate that it was a hierarchy. I didn't do the same for longer
paths (e.g., "refs/heads" remained, instead of becoming
"refs/heads/").
- in some cases, no change was made, as the text was explicitly about
unpacked refs (e.g., the discussion in git-pack-refs).
- In some cases it made sense instead to note the existence of packed
refs (e.g., in check-ref-format and rev-parse).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-18 02:16:20 +01:00
|
|
|
Pretend as if all the refs in `refs/remotes` are listed
|
2010-10-08 19:31:15 +02:00
|
|
|
on the command line as '<commit>'. If '<pattern>' is given, limit
|
2010-11-02 16:31:20 +01:00
|
|
|
remote-tracking branches to ones matching given shell glob.
|
2012-02-28 16:35:48 +01:00
|
|
|
If pattern lacks '?', '{asterisk}', or '[', '/{asterisk}' at the end is implied.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2010-10-08 19:31:15 +02:00
|
|
|
--glob=<glob-pattern>::
|
|
|
|
Pretend as if all the refs matching shell glob '<glob-pattern>'
|
2010-01-20 10:48:25 +01:00
|
|
|
are listed on the command line as '<commit>'. Leading 'refs/',
|
2012-02-28 16:35:48 +01:00
|
|
|
is automatically prepended if missing. If pattern lacks '?', '{asterisk}',
|
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|
|
or '[', '/{asterisk}' at the end is implied.
|
2010-01-20 10:48:25 +01:00
|
|
|
|
2013-09-02 22:11:26 +02:00
|
|
|
--exclude=<glob-pattern>::
|
|
|
|
|
|
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|
Do not include refs matching '<glob-pattern>' that the next `--all`,
|
|
|
|
`--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
|
|
|
|
consider. Repetitions of this option accumulate exclusion patterns
|
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|
|
up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
|
|
|
|
`--glob` option (other options or arguments do not clear
|
2014-11-03 21:37:07 +01:00
|
|
|
accumulated patterns).
|
2013-09-02 22:11:26 +02:00
|
|
|
+
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|
The patterns given should not begin with `refs/heads`, `refs/tags`, or
|
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|
|
`refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
|
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|
|
respectively, and they must begin with `refs/` when applied to `--glob`
|
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|
|
or `--all`. If a trailing '/{asterisk}' is intended, it must be given
|
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|
|
explicitly.
|
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|
2014-10-16 00:43:28 +02:00
|
|
|
--reflog::
|
|
|
|
Pretend as if all objects mentioned by reflogs are listed on the
|
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|
|
command line as `<commit>`.
|
|
|
|
|
2019-07-01 15:18:15 +02:00
|
|
|
--alternate-refs::
|
|
|
|
Pretend as if all objects mentioned as ref tips of alternate
|
|
|
|
repositories were listed on the command line. An alternate
|
|
|
|
repository is any repository whose object directory is specified
|
|
|
|
in `objects/info/alternates`. The set of included objects may
|
|
|
|
be modified by `core.alternateRefsCommand`, etc. See
|
|
|
|
linkgit:git-config[1].
|
|
|
|
|
2017-08-23 14:37:02 +02:00
|
|
|
--single-worktree::
|
|
|
|
By default, all working trees will be examined by the
|
|
|
|
following options when there are more than one (see
|
|
|
|
linkgit:git-worktree[1]): `--all`, `--reflog` and
|
|
|
|
`--indexed-objects`.
|
|
|
|
This option forces them to examine the current working tree
|
|
|
|
only.
|
|
|
|
|
2011-05-19 03:08:09 +02:00
|
|
|
--ignore-missing::
|
|
|
|
Upon seeing an invalid object name in the input, pretend as if
|
|
|
|
the bad input was not given.
|
2010-01-20 10:48:25 +01:00
|
|
|
|
2009-11-24 07:54:44 +01:00
|
|
|
ifndef::git-rev-list[]
|
|
|
|
--bisect::
|
docs: don't talk about $GIT_DIR/refs/ everywhere
It is misleading to say that we pull refs from $GIT_DIR/refs/*, because we
may also consult the packed refs mechanism. These days we tend to treat
the "refs hierarchy" as more of an abstract namespace that happens to be
represented as $GIT_DIR/refs. At best, this is a minor inaccuracy, but at
worst it can confuse users who then look in $GIT_DIR/refs and find that it
is missing some of the refs they expected to see.
This patch drops most uses of "$GIT_DIR/refs/*", changing them into just
"refs/*", under the assumption that users can handle the concept of an
abstract refs namespace. There are a few things to note:
- most cases just dropped the $GIT_DIR/ portion. But for cases where
that left _just_ the word "refs", I changed it to "refs/" to help
indicate that it was a hierarchy. I didn't do the same for longer
paths (e.g., "refs/heads" remained, instead of becoming
"refs/heads/").
- in some cases, no change was made, as the text was explicitly about
unpacked refs (e.g., the discussion in git-pack-refs).
- In some cases it made sense instead to note the existence of packed
refs (e.g., in check-ref-format and rev-parse).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-18 02:16:20 +01:00
|
|
|
Pretend as if the bad bisection ref `refs/bisect/bad`
|
2009-11-24 07:54:44 +01:00
|
|
|
was listed and as if it was followed by `--not` and the good
|
docs: don't talk about $GIT_DIR/refs/ everywhere
It is misleading to say that we pull refs from $GIT_DIR/refs/*, because we
may also consult the packed refs mechanism. These days we tend to treat
the "refs hierarchy" as more of an abstract namespace that happens to be
represented as $GIT_DIR/refs. At best, this is a minor inaccuracy, but at
worst it can confuse users who then look in $GIT_DIR/refs and find that it
is missing some of the refs they expected to see.
This patch drops most uses of "$GIT_DIR/refs/*", changing them into just
"refs/*", under the assumption that users can handle the concept of an
abstract refs namespace. There are a few things to note:
- most cases just dropped the $GIT_DIR/ portion. But for cases where
that left _just_ the word "refs", I changed it to "refs/" to help
indicate that it was a hierarchy. I didn't do the same for longer
paths (e.g., "refs/heads" remained, instead of becoming
"refs/heads/").
- in some cases, no change was made, as the text was explicitly about
unpacked refs (e.g., the discussion in git-pack-refs).
- In some cases it made sense instead to note the existence of packed
refs (e.g., in check-ref-format and rev-parse).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-18 02:16:20 +01:00
|
|
|
bisection refs `refs/bisect/good-*` on the command
|
2020-08-07 23:58:35 +02:00
|
|
|
line.
|
2009-11-24 07:54:44 +01:00
|
|
|
endif::git-rev-list[]
|
|
|
|
|
2008-01-18 23:58:57 +01:00
|
|
|
--stdin::
|
|
|
|
In addition to the '<commit>' listed on the command
|
2016-06-28 13:40:12 +02:00
|
|
|
line, read them from the standard input. If a `--` separator is
|
2009-11-20 11:50:21 +01:00
|
|
|
seen, stop reading commits and start reading paths to limit the
|
|
|
|
result.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2009-11-03 15:59:18 +01:00
|
|
|
ifdef::git-rev-list[]
|
2008-01-18 23:58:57 +01:00
|
|
|
--quiet::
|
|
|
|
Don't print anything to standard output. This form
|
|
|
|
is primarily meant to allow the caller to
|
|
|
|
test the exit status to see if a range of objects is fully
|
|
|
|
connected (or not). It is faster than redirecting stdout
|
2013-11-15 02:34:01 +01:00
|
|
|
to `/dev/null` as the output does not have to be formatted.
|
rev-list: add --disk-usage option for calculating disk usage
It can sometimes be useful to see which refs are contributing to the
overall repository size (e.g., does some branch have a bunch of objects
not found elsewhere in history, which indicates that deleting it would
shrink the size of a clone).
You can find that out by generating a list of objects, getting their
sizes from cat-file, and then summing them, like:
git rev-list --objects --no-object-names main..branch
git cat-file --batch-check='%(objectsize:disk)' |
perl -lne '$total += $_; END { print $total }'
Though note that the caveats from git-cat-file(1) apply here. We "blame"
base objects more than their deltas, even though the relationship could
easily be flipped. Still, it can be a useful rough measure.
But one problem is that it's slow to run. Teaching rev-list to sum up
the sizes can be much faster for two reasons:
1. It skips all of the piping of object names and sizes.
2. If bitmaps are in use, for objects that are in the
bitmapped packfile we can skip the oid_object_info()
lookup entirely, and just ask the revindex for the
on-disk size.
This patch implements a --disk-usage option which produces the same
answer in a fraction of the time. Here are some timings using a clone of
torvalds/linux:
[rev-list piped to cat-file, no bitmaps]
$ time git rev-list --objects --no-object-names --all |
git cat-file --buffer --batch-check='%(objectsize:disk)' |
perl -lne '$total += $_; END { print $total }'
1459938510
real 0m29.635s
user 0m38.003s
sys 0m1.093s
[internal, no bitmaps]
$ time git rev-list --disk-usage --objects --all
1459938510
real 0m31.262s
user 0m30.885s
sys 0m0.376s
Even though the wall-clock time is slightly worse due to parallelism,
notice the CPU savings between the two. We saved 21% of the CPU just by
avoiding the pipes.
But the real win is with bitmaps. If we use them without the new option:
[rev-list piped to cat-file, bitmaps]
$ time git rev-list --objects --no-object-names --all --use-bitmap-index |
git cat-file --batch-check='%(objectsize:disk)' |
perl -lne '$total += $_; END { print $total }'
1459938510
real 0m6.244s
user 0m8.452s
sys 0m0.311s
then we're faster to generate the list of objects, but we still spend a
lot of time piping and looking things up. But if we do both together:
[internal, bitmaps]
$ time git rev-list --disk-usage --objects --all --use-bitmap-index
1459938510
real 0m0.219s
user 0m0.169s
sys 0m0.049s
then we get the same answer much faster.
For "--all", that answer will correspond closely to "du objects/pack",
of course. But we're actually checking reachability here, so we're still
fast when we ask for more interesting things:
$ time git rev-list --disk-usage --use-bitmap-index v5.0..v5.10
374798628
real 0m0.429s
user 0m0.356s
sys 0m0.072s
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-09 11:53:50 +01:00
|
|
|
|
|
|
|
--disk-usage::
|
|
|
|
Suppress normal output; instead, print the sum of the bytes used
|
|
|
|
for on-disk storage by the selected commits or objects. This is
|
|
|
|
equivalent to piping the output into `git cat-file
|
|
|
|
--batch-check='%(objectsize:disk)'`, except that it runs much
|
|
|
|
faster (especially with `--use-bitmap-index`). See the `CAVEATS`
|
|
|
|
section in linkgit:git-cat-file[1] for the limitations of what
|
|
|
|
"on-disk storage" means.
|
2008-06-04 08:56:56 +02:00
|
|
|
endif::git-rev-list[]
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2011-03-07 13:31:41 +01:00
|
|
|
--cherry-mark::
|
|
|
|
Like `--cherry-pick` (see below) but mark equivalent commits
|
|
|
|
with `=` rather than omitting them, and inequivalent ones with `+`.
|
|
|
|
|
2008-01-18 23:58:57 +01:00
|
|
|
--cherry-pick::
|
|
|
|
Omit any commit that introduces the same change as
|
2013-11-15 02:34:01 +01:00
|
|
|
another commit on the ``other side'' when the set of
|
2008-01-18 23:58:57 +01:00
|
|
|
commits are limited with symmetric difference.
|
|
|
|
+
|
|
|
|
For example, if you have two branches, `A` and `B`, a usual way
|
|
|
|
to list all commits on only one side of them is with
|
2011-04-01 20:04:46 +02:00
|
|
|
`--left-right` (see the example below in the description of
|
2013-11-15 02:34:02 +01:00
|
|
|
the `--left-right` option). However, it shows the commits that were
|
|
|
|
cherry-picked from the other branch (for example, ``3rd on b'' may be
|
|
|
|
cherry-picked from branch A). With this option, such pairs of commits are
|
2008-01-18 23:58:57 +01:00
|
|
|
excluded from the output.
|
|
|
|
|
2011-02-21 17:09:12 +01:00
|
|
|
--left-only::
|
|
|
|
--right-only::
|
2016-07-20 23:10:00 +02:00
|
|
|
List only commits on the respective side of a symmetric difference,
|
2011-02-21 17:09:12 +01:00
|
|
|
i.e. only those which would be marked `<` resp. `>` by
|
|
|
|
`--left-right`.
|
|
|
|
+
|
|
|
|
For example, `--cherry-pick --right-only A...B` omits those
|
|
|
|
commits from `B` which are in `A` or are patch-equivalent to a commit in
|
docs: stop using asciidoc no-inline-literal
In asciidoc 7, backticks like `foo` produced a typographic
effect, but did not otherwise affect the syntax. In asciidoc
8, backticks introduce an "inline literal" inside which markup
is not interpreted. To keep compatibility with existing
documents, asciidoc 8 has a "no-inline-literal" attribute to
keep the old behavior. We enabled this so that the
documentation could be built on either version.
It has been several years now, and asciidoc 7 is no longer
in wide use. We can now decide whether or not we want
inline literals on their own merits, which are:
1. The source is much easier to read when the literal
contains punctuation. You can use `master~1` instead
of `master{tilde}1`.
2. They are less error-prone. Because of point (1), we
tend to make mistakes and forget the extra layer of
quoting.
This patch removes the no-inline-literal attribute from the
Makefile and converts every use of backticks in the
documentation to an inline literal (they must be cleaned up,
or the example above would literally show "{tilde}" in the
output).
Problematic sites were found by grepping for '`.*[{\\]' and
examined and fixed manually. The results were then verified
by comparing the output of "html2text" on the set of
generated html pages. Doing so revealed that in addition to
making the source more readable, this patch fixes several
formatting bugs:
- HTML rendering used the ellipsis character instead of
literal "..." in code examples (like "git log A...B")
- some code examples used the right-arrow character
instead of '->' because they failed to quote
- api-config.txt did not quote tilde, and the resulting
HTML contained a bogus snippet like:
<tt><sub></tt> foo <tt></sub>bar</tt>
which caused some parsers to choke and omit whole
sections of the page.
- git-commit.txt confused ``foo`` (backticks inside a
literal) with ``foo'' (matched double-quotes)
- mentions of `A U Thor <author@example.com>` used to
erroneously auto-generate a mailto footnote for
author@example.com
- the description of --word-diff=plain incorrectly showed
the output as "[-removed-] and {added}", not "{+added+}".
- using "prime" notation like:
commit `C` and its replacement `C'`
confused asciidoc into thinking that everything between
the first backtick and the final apostrophe were meant
to be inside matched quotes
- asciidoc got confused by the escaping of some of our
asterisks. In particular,
`credential.\*` and `credential.<url>.\*`
properly escaped the asterisk in the first case, but
literally passed through the backslash in the second
case.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-04-26 10:51:57 +02:00
|
|
|
`A`. In other words, this lists the `+` commits from `git cherry A B`.
|
2011-02-21 17:09:12 +01:00
|
|
|
More precisely, `--cherry-pick --right-only --no-merges` gives the exact
|
|
|
|
list.
|
|
|
|
|
2011-03-07 13:31:42 +01:00
|
|
|
--cherry::
|
|
|
|
A synonym for `--right-only --cherry-mark --no-merges`; useful to
|
|
|
|
limit the output to the commits on our side and mark those that
|
|
|
|
have been applied to the other side of a forked history with
|
|
|
|
`git log --cherry upstream...mybranch`, similar to
|
|
|
|
`git cherry upstream mybranch`.
|
|
|
|
|
2008-06-08 03:36:09 +02:00
|
|
|
-g::
|
|
|
|
--walk-reflogs::
|
2008-01-18 23:58:57 +01:00
|
|
|
Instead of walking the commit ancestry chain, walk
|
|
|
|
reflog entries from the most recent one to older ones.
|
|
|
|
When this option is used you cannot specify commits to
|
|
|
|
exclude (that is, '{caret}commit', 'commit1..commit2',
|
2014-04-01 00:11:44 +02:00
|
|
|
and 'commit1\...commit2' notations cannot be used).
|
2008-01-18 23:58:57 +01:00
|
|
|
+
|
2019-11-20 01:51:25 +01:00
|
|
|
With `--pretty` format other than `oneline` and `reference` (for obvious reasons),
|
2008-01-18 23:58:57 +01:00
|
|
|
this causes the output to have two extra lines of information
|
2016-07-22 21:51:32 +02:00
|
|
|
taken from the reflog. The reflog designator in the output may be shown
|
|
|
|
as `ref@{Nth}` (where `Nth` is the reverse-chronological index in the
|
|
|
|
reflog) or as `ref@{timestamp}` (with the timestamp for that entry),
|
|
|
|
depending on a few rules:
|
|
|
|
+
|
|
|
|
--
|
|
|
|
1. If the starting point is specified as `ref@{Nth}`, show the index
|
2019-01-22 21:16:35 +01:00
|
|
|
format.
|
2016-07-22 21:51:32 +02:00
|
|
|
+
|
|
|
|
2. If the starting point was specified as `ref@{now}`, show the
|
2019-01-22 21:16:35 +01:00
|
|
|
timestamp format.
|
2016-07-22 21:51:32 +02:00
|
|
|
+
|
|
|
|
3. If neither was used, but `--date` was given on the command line, show
|
2019-01-22 21:16:35 +01:00
|
|
|
the timestamp in the format requested by `--date`.
|
2016-07-22 21:51:32 +02:00
|
|
|
+
|
|
|
|
4. Otherwise, show the index format.
|
|
|
|
--
|
|
|
|
+
|
|
|
|
Under `--pretty=oneline`, the commit message is
|
2008-01-18 23:58:57 +01:00
|
|
|
prefixed with this information on the same line.
|
2013-11-15 02:34:01 +01:00
|
|
|
This option cannot be combined with `--reverse`.
|
2008-01-18 23:58:57 +01:00
|
|
|
See also linkgit:git-reflog[1].
|
2019-11-20 01:51:25 +01:00
|
|
|
+
|
|
|
|
Under `--pretty=reference`, this information will not be shown at all.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
|
|
|
--merge::
|
|
|
|
After a failed merge, show refs that touch files having a
|
|
|
|
conflict and don't exist on all heads to merge.
|
|
|
|
|
|
|
|
--boundary::
|
2013-05-16 17:32:33 +02:00
|
|
|
Output excluded boundary commits. Boundary commits are
|
|
|
|
prefixed with `-`.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
rev-list: add bitmap mode to speed up object lists
The bitmap reachability index used to speed up the counting objects
phase during `pack-objects` can also be used to optimize a normal
rev-list if the only thing required are the SHA1s of the objects during
the list (i.e., not the path names at which trees and blobs were found).
Calling `git rev-list --objects --use-bitmap-index [committish]` will
perform an object iteration based on a bitmap result instead of actually
walking the object graph.
These are some example timings for `torvalds/linux` (warm cache,
best-of-five):
$ time git rev-list --objects master > /dev/null
real 0m34.191s
user 0m33.904s
sys 0m0.268s
$ time git rev-list --objects --use-bitmap-index master > /dev/null
real 0m1.041s
user 0m0.976s
sys 0m0.064s
Likewise, using `git rev-list --count --use-bitmap-index` will speed up
the counting operation by building the resulting bitmap and performing a
fast popcount (number of bits set on the bitmap) on the result.
Here are some sample timings of different ways to count commits in
`torvalds/linux`:
$ time git rev-list master | wc -l
399882
real 0m6.524s
user 0m6.060s
sys 0m3.284s
$ time git rev-list --count master
399882
real 0m4.318s
user 0m4.236s
sys 0m0.076s
$ time git rev-list --use-bitmap-index --count master
399882
real 0m0.217s
user 0m0.176s
sys 0m0.040s
This also respects negative refs, so you can use it to count
a slice of history:
$ time git rev-list --count v3.0..master
144843
real 0m1.971s
user 0m1.932s
sys 0m0.036s
$ time git rev-list --use-bitmap-index --count v3.0..master
real 0m0.280s
user 0m0.220s
sys 0m0.056s
Though note that the closer the endpoints, the less it helps. In the
traversal case, we have fewer commits to cross, so we take less time.
But the bitmap time is dominated by generating the pack revindex, which
is constant with respect to the refs given.
Note that you cannot yet get a fast --left-right count of a symmetric
difference (e.g., "--count --left-right master...topic"). The slow part
of that walk actually happens during the merge-base determination when
we parse "master...topic". Even though a count does not actually need to
know the real merge base (it only needs to take the symmetric difference
of the bitmaps), the revision code would require some refactoring to
handle this case.
Additionally, a `--test-bitmap` flag has been added that will perform
the same rev-list manually (i.e. using a normal revwalk) and using
bitmaps, and verify that the results are the same. This can be used to
exercise the bitmap code, and also to verify that the contents of the
.bitmap file are sane.
Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 15:00:12 +01:00
|
|
|
ifdef::git-rev-list[]
|
|
|
|
--use-bitmap-index::
|
|
|
|
|
|
|
|
Try to speed up the traversal using the pack bitmap index (if
|
|
|
|
one is available). Note that when traversing with `--objects`,
|
|
|
|
trees and blobs will not have their associated path printed.
|
2016-07-20 15:28:09 +02:00
|
|
|
|
|
|
|
--progress=<header>::
|
|
|
|
Show progress reports on stderr as objects are considered. The
|
|
|
|
`<header>` text will be printed with each progress update.
|
rev-list: add bitmap mode to speed up object lists
The bitmap reachability index used to speed up the counting objects
phase during `pack-objects` can also be used to optimize a normal
rev-list if the only thing required are the SHA1s of the objects during
the list (i.e., not the path names at which trees and blobs were found).
Calling `git rev-list --objects --use-bitmap-index [committish]` will
perform an object iteration based on a bitmap result instead of actually
walking the object graph.
These are some example timings for `torvalds/linux` (warm cache,
best-of-five):
$ time git rev-list --objects master > /dev/null
real 0m34.191s
user 0m33.904s
sys 0m0.268s
$ time git rev-list --objects --use-bitmap-index master > /dev/null
real 0m1.041s
user 0m0.976s
sys 0m0.064s
Likewise, using `git rev-list --count --use-bitmap-index` will speed up
the counting operation by building the resulting bitmap and performing a
fast popcount (number of bits set on the bitmap) on the result.
Here are some sample timings of different ways to count commits in
`torvalds/linux`:
$ time git rev-list master | wc -l
399882
real 0m6.524s
user 0m6.060s
sys 0m3.284s
$ time git rev-list --count master
399882
real 0m4.318s
user 0m4.236s
sys 0m0.076s
$ time git rev-list --use-bitmap-index --count master
399882
real 0m0.217s
user 0m0.176s
sys 0m0.040s
This also respects negative refs, so you can use it to count
a slice of history:
$ time git rev-list --count v3.0..master
144843
real 0m1.971s
user 0m1.932s
sys 0m0.036s
$ time git rev-list --use-bitmap-index --count v3.0..master
real 0m0.280s
user 0m0.220s
sys 0m0.056s
Though note that the closer the endpoints, the less it helps. In the
traversal case, we have fewer commits to cross, so we take less time.
But the bitmap time is dominated by generating the pack revindex, which
is constant with respect to the refs given.
Note that you cannot yet get a fast --left-right count of a symmetric
difference (e.g., "--count --left-right master...topic"). The slow part
of that walk actually happens during the merge-base determination when
we parse "master...topic". Even though a count does not actually need to
know the real merge base (it only needs to take the symmetric difference
of the bitmaps), the revision code would require some refactoring to
handle this case.
Additionally, a `--test-bitmap` flag has been added that will perform
the same rev-list manually (i.e. using a normal revwalk) and using
bitmaps, and verify that the results are the same. This can be used to
exercise the bitmap code, and also to verify that the contents of the
.bitmap file are sane.
Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 15:00:12 +01:00
|
|
|
endif::git-rev-list[]
|
|
|
|
|
2008-08-12 01:55:36 +02:00
|
|
|
History Simplification
|
|
|
|
~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
|
2008-11-12 11:51:28 +01:00
|
|
|
Sometimes you are only interested in parts of the history, for example the
|
|
|
|
commits modifying a particular <path>. But there are two parts of
|
|
|
|
'History Simplification', one part is selecting the commits and the other
|
|
|
|
is how to do it, as there are various strategies to simplify the history.
|
|
|
|
|
|
|
|
The following options select the commits to be shown:
|
|
|
|
|
|
|
|
<paths>::
|
|
|
|
Commits modifying the given <paths> are selected.
|
|
|
|
|
|
|
|
--simplify-by-decoration::
|
|
|
|
Commits that are referred by some branch or tag are selected.
|
|
|
|
|
|
|
|
Note that extra commits can be shown to give a meaningful history.
|
|
|
|
|
|
|
|
The following options affect the way the simplification is performed:
|
|
|
|
|
|
|
|
Default mode::
|
|
|
|
Simplifies the history to the simplest history explaining the
|
|
|
|
final state of the tree. Simplest because it prunes some side
|
|
|
|
branches if the end result is the same (i.e. merging branches
|
|
|
|
with the same content)
|
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
--show-pulls::
|
|
|
|
Include all commits from the default mode, but also any merge
|
|
|
|
commits that are not TREESAME to the first parent but are
|
|
|
|
TREESAME to a later parent. This mode is helpful for showing
|
|
|
|
the merge commits that "first introduced" a change to a branch.
|
|
|
|
|
2008-11-12 11:51:28 +01:00
|
|
|
--full-history::
|
2011-07-22 03:33:15 +02:00
|
|
|
Same as the default mode, but does not prune some history.
|
2008-11-12 11:51:28 +01:00
|
|
|
|
|
|
|
--dense::
|
|
|
|
Only the selected commits are shown, plus some to have a
|
|
|
|
meaningful history.
|
|
|
|
|
|
|
|
--sparse::
|
|
|
|
All commits in the simplified history are shown.
|
|
|
|
|
|
|
|
--simplify-merges::
|
2013-11-15 02:34:01 +01:00
|
|
|
Additional option to `--full-history` to remove some needless
|
2008-11-12 11:51:28 +01:00
|
|
|
merges from the resulting history, as there are no selected
|
|
|
|
commits contributing to this merge.
|
|
|
|
|
2010-06-04 01:17:35 +02:00
|
|
|
--ancestry-path::
|
|
|
|
When given a range of commits to display (e.g. 'commit1..commit2'
|
|
|
|
or 'commit2 {caret}commit1'), only display commits that exist
|
|
|
|
directly on the ancestry chain between the 'commit1' and
|
|
|
|
'commit2', i.e. commits that are both descendants of 'commit1',
|
|
|
|
and ancestors of 'commit2'.
|
|
|
|
|
2008-11-12 11:51:28 +01:00
|
|
|
A more detailed explanation follows.
|
2008-08-12 01:55:36 +02:00
|
|
|
|
|
|
|
Suppose you specified `foo` as the <paths>. We shall call commits
|
|
|
|
that modify `foo` !TREESAME, and the rest TREESAME. (In a diff
|
|
|
|
filtered for `foo`, they look different and equal, respectively.)
|
|
|
|
|
|
|
|
In the following, we will always refer to the same example history to
|
|
|
|
illustrate the differences between simplification settings. We assume
|
|
|
|
that you are filtering for a file `foo` in this commit graph:
|
|
|
|
-----------------------------------------------------------------------
|
2013-05-16 17:32:37 +02:00
|
|
|
.-A---M---N---O---P---Q
|
|
|
|
/ / / / / /
|
|
|
|
I B C D E Y
|
|
|
|
\ / / / / /
|
|
|
|
`-------------' X
|
2008-08-12 01:55:36 +02:00
|
|
|
-----------------------------------------------------------------------
|
2013-05-16 17:32:37 +02:00
|
|
|
The horizontal line of history A---Q is taken to be the first parent of
|
2008-08-12 01:55:36 +02:00
|
|
|
each merge. The commits are:
|
|
|
|
|
|
|
|
* `I` is the initial commit, in which `foo` exists with contents
|
2013-11-15 02:34:01 +01:00
|
|
|
``asdf'', and a file `quux` exists with contents ``quux''. Initial
|
2008-08-12 01:55:36 +02:00
|
|
|
commits are compared to an empty tree, so `I` is !TREESAME.
|
|
|
|
|
2013-11-15 02:34:01 +01:00
|
|
|
* In `A`, `foo` contains just ``foo''.
|
2008-08-12 01:55:36 +02:00
|
|
|
|
|
|
|
* `B` contains the same change as `A`. Its merge `M` is trivial and
|
|
|
|
hence TREESAME to all parents.
|
|
|
|
|
2013-11-15 02:34:01 +01:00
|
|
|
* `C` does not change `foo`, but its merge `N` changes it to ``foobar'',
|
2008-08-12 01:55:36 +02:00
|
|
|
so it is not TREESAME to any parent.
|
|
|
|
|
2013-11-15 02:34:01 +01:00
|
|
|
* `D` sets `foo` to ``baz''. Its merge `O` combines the strings from
|
|
|
|
`N` and `D` to ``foobarbaz''; i.e., it is not TREESAME to any parent.
|
2008-08-12 01:55:36 +02:00
|
|
|
|
2013-11-15 02:34:01 +01:00
|
|
|
* `E` changes `quux` to ``xyzzy'', and its merge `P` combines the
|
|
|
|
strings to ``quux xyzzy''. `P` is TREESAME to `O`, but not to `E`.
|
2008-08-12 01:55:36 +02:00
|
|
|
|
2013-07-22 23:02:23 +02:00
|
|
|
* `X` is an independent root commit that added a new file `side`, and `Y`
|
2013-05-16 17:32:37 +02:00
|
|
|
modified it. `Y` is TREESAME to `X`. Its merge `Q` added `side` to `P`, and
|
|
|
|
`Q` is TREESAME to `P`, but not to `Y`.
|
|
|
|
|
2013-11-15 02:34:01 +01:00
|
|
|
`rev-list` walks backwards through history, including or excluding
|
|
|
|
commits based on whether `--full-history` and/or parent rewriting
|
|
|
|
(via `--parents` or `--children`) are used. The following settings
|
2008-08-12 01:55:36 +02:00
|
|
|
are available.
|
|
|
|
|
|
|
|
Default mode::
|
|
|
|
Commits are included if they are not TREESAME to any parent
|
2013-11-15 02:34:01 +01:00
|
|
|
(though this can be changed, see `--sparse` below). If the
|
2008-08-12 01:55:36 +02:00
|
|
|
commit was a merge, and it was TREESAME to one parent, follow
|
|
|
|
only that parent. (Even if there are several TREESAME
|
|
|
|
parents, follow only one of them.) Otherwise, follow all
|
|
|
|
parents.
|
|
|
|
+
|
|
|
|
This results in:
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
.-A---N---O
|
2010-06-04 01:17:33 +02:00
|
|
|
/ / /
|
2008-08-12 01:55:36 +02:00
|
|
|
I---------D
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
+
|
|
|
|
Note how the rule to only follow the TREESAME parent, if one is
|
|
|
|
available, removed `B` from consideration entirely. `C` was
|
|
|
|
considered via `N`, but is TREESAME. Root commits are compared to an
|
|
|
|
empty tree, so `I` is !TREESAME.
|
|
|
|
+
|
2013-11-15 02:34:01 +01:00
|
|
|
Parent/child relations are only visible with `--parents`, but that does
|
2008-08-12 01:55:36 +02:00
|
|
|
not affect the commits selected in default mode, so we have shown the
|
|
|
|
parent lines.
|
|
|
|
|
|
|
|
--full-history without parent rewriting::
|
|
|
|
This mode differs from the default in one point: always follow
|
|
|
|
all parents of a merge, even if it is TREESAME to one of them.
|
|
|
|
Even if more than one side of the merge has commits that are
|
|
|
|
included, this does not imply that the merge itself is! In
|
|
|
|
the example, we get
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
2013-05-16 17:32:37 +02:00
|
|
|
I A B N D O P Q
|
2008-08-12 01:55:36 +02:00
|
|
|
-----------------------------------------------------------------------
|
|
|
|
+
|
revision.c: Make --full-history consider more merges
History simplification previously always treated merges as TREESAME
if they were TREESAME to any parent.
While this was consistent with the default behaviour, this could be
extremely unhelpful when searching detailed history, and could not be
overridden. For example, if a merge had ignored a change, as if by "-s
ours", then:
git log -m -p --full-history -Schange file
would successfully locate "change"'s addition but would not locate the
merge that resolved against it.
Futher, simplify_merges could drop the actual parent that a commit
was TREESAME to, leaving it as a normal commit marked TREESAME that
isn't actually TREESAME to its remaining parent.
Now redefine a commit's TREESAME flag to be true only if a commit is
TREESAME to _all_ of its parents. This doesn't affect either the default
simplify_history behaviour (because partially TREESAME merges are turned
into normal commits), or full-history with parent rewriting (because all
merges are output). But it does affect other modes. The clearest
difference is that --full-history will show more merges - sufficient to
ensure that -m -p --full-history log searches can really explain every
change to the file, including those changes' ultimate fate in merges.
Also modify simplify_merges to recalculate TREESAME after removing
a parent. This is achieved by storing per-parent TREESAME flags on the
initial scan, so the combined flag can be easily recomputed.
This fixes some t6111 failures, but creates a couple of new ones -
we are now showing some merges that don't need to be shown.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-16 17:32:34 +02:00
|
|
|
`M` was excluded because it is TREESAME to both parents. `E`,
|
2008-08-12 01:55:36 +02:00
|
|
|
`C` and `B` were all walked, but only `B` was !TREESAME, so the others
|
|
|
|
do not appear.
|
|
|
|
+
|
|
|
|
Note that without parent rewriting, it is not really possible to talk
|
|
|
|
about the parent/child relationships between the commits, so we show
|
|
|
|
them disconnected.
|
|
|
|
|
|
|
|
--full-history with parent rewriting::
|
|
|
|
Ordinary commits are only included if they are !TREESAME
|
2013-11-15 02:34:01 +01:00
|
|
|
(though this can be changed, see `--sparse` below).
|
2008-08-12 01:55:36 +02:00
|
|
|
+
|
|
|
|
Merges are always included. However, their parent list is rewritten:
|
|
|
|
Along each parent, prune away commits that are not included
|
|
|
|
themselves. This results in
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
2013-05-16 17:32:37 +02:00
|
|
|
.-A---M---N---O---P---Q
|
2008-08-12 01:55:36 +02:00
|
|
|
/ / / / /
|
|
|
|
I B / D /
|
|
|
|
\ / / / /
|
|
|
|
`-------------'
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
+
|
2013-11-15 02:34:01 +01:00
|
|
|
Compare to `--full-history` without rewriting above. Note that `E`
|
2008-08-12 01:55:36 +02:00
|
|
|
was pruned away because it is TREESAME, but the parent list of P was
|
|
|
|
rewritten to contain `E`'s parent `I`. The same happened for `C` and
|
2013-05-16 17:32:37 +02:00
|
|
|
`N`, and `X`, `Y` and `Q`.
|
2008-08-12 01:55:36 +02:00
|
|
|
|
|
|
|
In addition to the above settings, you can change whether TREESAME
|
|
|
|
affects inclusion:
|
|
|
|
|
2008-06-08 03:36:09 +02:00
|
|
|
--dense::
|
2008-08-12 01:55:36 +02:00
|
|
|
Commits that are walked are included if they are not TREESAME
|
|
|
|
to any parent.
|
|
|
|
|
2008-06-08 03:36:09 +02:00
|
|
|
--sparse::
|
2008-08-12 01:55:36 +02:00
|
|
|
All commits that are walked are included.
|
|
|
|
+
|
2013-11-15 02:34:01 +01:00
|
|
|
Note that without `--full-history`, this still simplifies merges: if
|
2008-08-12 01:55:36 +02:00
|
|
|
one of the parents is TREESAME, we follow only that one, so the other
|
|
|
|
sides of the merge are never walked.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2008-08-12 01:55:37 +02:00
|
|
|
--simplify-merges::
|
|
|
|
First, build a history graph in the same way that
|
2013-11-15 02:34:01 +01:00
|
|
|
`--full-history` with parent rewriting does (see above).
|
2008-08-12 01:55:37 +02:00
|
|
|
+
|
|
|
|
Then simplify each commit `C` to its replacement `C'` in the final
|
|
|
|
history according to the following rules:
|
|
|
|
+
|
|
|
|
--
|
|
|
|
* Set `C'` to `C`.
|
|
|
|
+
|
|
|
|
* Replace each parent `P` of `C'` with its simplification `P'`. In
|
2013-05-16 17:32:37 +02:00
|
|
|
the process, drop parents that are ancestors of other parents or that are
|
|
|
|
root commits TREESAME to an empty tree, and remove duplicates, but take care
|
|
|
|
to never drop all parents that we are TREESAME to.
|
2008-08-12 01:55:37 +02:00
|
|
|
+
|
|
|
|
* If after this parent rewriting, `C'` is a root or merge commit (has
|
|
|
|
zero or >1 parents), a boundary commit, or !TREESAME, it remains.
|
|
|
|
Otherwise, it is replaced with its only parent.
|
|
|
|
--
|
|
|
|
+
|
|
|
|
The effect of this is best shown by way of comparing to
|
2013-11-15 02:34:01 +01:00
|
|
|
`--full-history` with parent rewriting. The example turns into:
|
2008-08-12 01:55:37 +02:00
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
.-A---M---N---O
|
|
|
|
/ / /
|
|
|
|
I B D
|
|
|
|
\ / /
|
|
|
|
`---------'
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
+
|
2013-11-15 02:34:02 +01:00
|
|
|
Note the major differences in `N`, `P`, and `Q` over `--full-history`:
|
2008-08-12 01:55:37 +02:00
|
|
|
+
|
|
|
|
--
|
|
|
|
* `N`'s parent list had `I` removed, because it is an ancestor of the
|
|
|
|
other parent `M`. Still, `N` remained because it is !TREESAME.
|
|
|
|
+
|
|
|
|
* `P`'s parent list similarly had `I` removed. `P` was then
|
|
|
|
removed completely, because it had one parent and is TREESAME.
|
2013-05-16 17:32:37 +02:00
|
|
|
+
|
|
|
|
* `Q`'s parent list had `Y` simplified to `X`. `X` was then removed, because it
|
|
|
|
was a TREESAME root. `Q` was then removed completely, because it had one
|
|
|
|
parent and is TREESAME.
|
2008-08-12 01:55:37 +02:00
|
|
|
--
|
2008-01-18 23:58:57 +01:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
There is another simplification mode available:
|
2010-06-04 01:17:35 +02:00
|
|
|
|
|
|
|
--ancestry-path::
|
|
|
|
Limit the displayed commits to those directly on the ancestry
|
2013-11-15 02:34:01 +01:00
|
|
|
chain between the ``from'' and ``to'' commits in the given commit
|
|
|
|
range. I.e. only display commits that are ancestor of the ``to''
|
2013-11-15 02:34:02 +01:00
|
|
|
commit and descendants of the ``from'' commit.
|
2010-06-04 01:17:35 +02:00
|
|
|
+
|
|
|
|
As an example use case, consider the following commit history:
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
D---E-------F
|
|
|
|
/ \ \
|
|
|
|
B---C---G---H---I---J
|
|
|
|
/ \
|
|
|
|
A-------K---------------L--M
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
+
|
|
|
|
A regular 'D..M' computes the set of commits that are ancestors of `M`,
|
|
|
|
but excludes the ones that are ancestors of `D`. This is useful to see
|
|
|
|
what happened to the history leading to `M` since `D`, in the sense
|
2013-11-15 02:34:01 +01:00
|
|
|
that ``what does `M` have that did not exist in `D`''. The result in this
|
2010-06-04 01:17:35 +02:00
|
|
|
example would be all the commits, except `A` and `B` (and `D` itself,
|
|
|
|
of course).
|
|
|
|
+
|
|
|
|
When we want to find out what commits in `M` are contaminated with the
|
|
|
|
bug introduced by `D` and need fixing, however, we might want to view
|
|
|
|
only the subset of 'D..M' that are actually descendants of `D`, i.e.
|
2013-11-15 02:34:01 +01:00
|
|
|
excluding `C` and `K`. This is exactly what the `--ancestry-path`
|
2010-06-04 01:17:35 +02:00
|
|
|
option does. Applied to the 'D..M' range, it results in:
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
E-------F
|
|
|
|
\ \
|
|
|
|
G---H---I---J
|
|
|
|
\
|
|
|
|
L--M
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
Before discussing another option, `--show-pulls`, we need to
|
|
|
|
create a new example history.
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
A common problem users face when looking at simplified history is that a
|
|
|
|
commit they know changed a file somehow does not appear in the file's
|
|
|
|
simplified history. Let's demonstrate a new example and show how options
|
|
|
|
such as `--full-history` and `--simplify-merges` works in that case:
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
-----------------------------------------------------------------------
|
|
|
|
.-A---M-----C--N---O---P
|
|
|
|
/ / \ \ \/ / /
|
|
|
|
I B \ R-'`-Z' /
|
|
|
|
\ / \/ /
|
|
|
|
\ / /\ /
|
|
|
|
`---X--' `---Y--'
|
|
|
|
-----------------------------------------------------------------------
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
For this example, suppose `I` created `file.txt` which was modified by
|
|
|
|
`A`, `B`, and `X` in different ways. The single-parent commits `C`, `Z`,
|
|
|
|
and `Y` do not change `file.txt`. The merge commit `M` was created by
|
|
|
|
resolving the merge conflict to include both changes from `A` and `B`
|
|
|
|
and hence is not TREESAME to either. The merge commit `R`, however, was
|
|
|
|
created by ignoring the contents of `file.txt` at `M` and taking only
|
|
|
|
the contents of `file.txt` at `X`. Hence, `R` is TREESAME to `X` but not
|
|
|
|
`M`. Finally, the natural merge resolution to create `N` is to take the
|
|
|
|
contents of `file.txt` at `R`, so `N` is TREESAME to `R` but not `C`.
|
|
|
|
The merge commits `O` and `P` are TREESAME to their first parents, but
|
|
|
|
not to their second parents, `Z` and `Y` respectively.
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
When using the default mode, `N` and `R` both have a TREESAME parent, so
|
|
|
|
those edges are walked and the others are ignored. The resulting history
|
|
|
|
graph is:
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
-----------------------------------------------------------------------
|
|
|
|
I---X
|
|
|
|
-----------------------------------------------------------------------
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
When using `--full-history`, Git walks every edge. This will discover
|
|
|
|
the commits `A` and `B` and the merge `M`, but also will reveal the
|
|
|
|
merge commits `O` and `P`. With parent rewriting, the resulting graph is:
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
-----------------------------------------------------------------------
|
|
|
|
.-A---M--------N---O---P
|
|
|
|
/ / \ \ \/ / /
|
|
|
|
I B \ R-'`--' /
|
|
|
|
\ / \/ /
|
|
|
|
\ / /\ /
|
|
|
|
`---X--' `------'
|
|
|
|
-----------------------------------------------------------------------
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
Here, the merge commits `O` and `P` contribute extra noise, as they did
|
|
|
|
not actually contribute a change to `file.txt`. They only merged a topic
|
|
|
|
that was based on an older version of `file.txt`. This is a common
|
|
|
|
issue in repositories using a workflow where many contributors work in
|
|
|
|
parallel and merge their topic branches along a single trunk: manu
|
|
|
|
unrelated merges appear in the `--full-history` results.
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
When using the `--simplify-merges` option, the commits `O` and `P`
|
|
|
|
disappear from the results. This is because the rewritten second parents
|
|
|
|
of `O` and `P` are reachable from their first parents. Those edges are
|
|
|
|
removed and then the commits look like single-parent commits that are
|
|
|
|
TREESAME to their parent. This also happens to the commit `N`, resulting
|
|
|
|
in a history view as follows:
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
-----------------------------------------------------------------------
|
|
|
|
.-A---M--.
|
|
|
|
/ / \
|
|
|
|
I B R
|
|
|
|
\ / /
|
|
|
|
\ / /
|
|
|
|
`---X--'
|
|
|
|
-----------------------------------------------------------------------
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
In this view, we see all of the important single-parent changes from
|
|
|
|
`A`, `B`, and `X`. We also see the carefully-resolved merge `M` and the
|
|
|
|
not-so-carefully-resolved merge `R`. This is usually enough information
|
|
|
|
to determine why the commits `A` and `B` "disappeared" from history in
|
|
|
|
the default view. However, there are a few issues with this approach.
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
The first issue is performance. Unlike any previous option, the
|
|
|
|
`--simplify-merges` option requires walking the entire commit history
|
|
|
|
before returning a single result. This can make the option difficult to
|
|
|
|
use for very large repositories.
|
2020-05-25 19:06:07 +02:00
|
|
|
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
The second issue is one of auditing. When many contributors are working
|
|
|
|
on the same repository, it is important which merge commits introduced
|
|
|
|
a change into an important branch. The problematic merge `R` above is
|
|
|
|
not likely to be the merge commit that was used to merge into an
|
|
|
|
important branch. Instead, the merge `N` was used to merge `R` and `X`
|
|
|
|
into the important branch. This commit may have information about why
|
|
|
|
the change `X` came to override the changes from `A` and `B` in its
|
|
|
|
commit message.
|
2020-05-25 19:06:07 +02:00
|
|
|
|
|
|
|
--show-pulls::
|
|
|
|
In addition to the commits shown in the default history, show
|
|
|
|
each merge commit that is not TREESAME to its first parent but
|
|
|
|
is TREESAME to a later parent.
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
+
|
2020-05-25 19:06:07 +02:00
|
|
|
When a merge commit is included by `--show-pulls`, the merge is
|
revision: --show-pulls adds helpful merges
The default file history simplification of "git log -- <path>" or
"git rev-list -- <path>" focuses on providing the smallest set of
commits that first contributed a change. The revision walk greatly
restricts the set of walked commits by visiting only the first
TREESAME parent of a merge commit, when one exists. This means
that portions of the commit-graph are not walked, which can be a
performance benefit, but can also "hide" commits that added changes
but were ignored by a merge resolution.
The --full-history option modifies this by walking all commits and
reporting a merge commit as "interesting" if it has _any_ parent
that is not TREESAME. This tends to be an over-representation of
important commits, especially in an environment where most merge
commits are created by pull request completion.
Suppose we have a commit A and we create a commit B on top that
changes our file. When we merge the pull request, we create a merge
commit M. If no one else changed the file in the first-parent
history between M and A, then M will not be TREESAME to its first
parent, but will be TREESAME to B. Thus, the simplified history
will be "B". However, M will appear in the --full-history mode.
However, suppose that a number of topics T1, T2, ..., Tn were
created based on commits C1, C2, ..., Cn between A and M as
follows:
A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn
\ \ \ \ / / / /
\ \__.. \ \/ ..__T1 / Tn
\ \__.. /\ ..__T2 /
\_____________________B \____________________/
If the commits T1, T2, ... Tn did not change the file, then all of
P1 through Pn will be TREESAME to their first parent, but not
TREESAME to their second. This means that all of those merge commits
appear in the --full-history view, with edges that immediately
collapse into the lower history without introducing interesting
single-parent commits.
The --simplify-merges option was introduced to remove these extra
merge commits. By noticing that the rewritten parents are reachable
from their first parents, those edges can be simplified away. Finally,
the commits now look like single-parent commits that are TREESAME to
their "only" parent. Thus, they are removed and this issue does not
cause issues anymore. However, this also ends up removing the commit
M from the history view! Even worse, the --simplify-merges option
requires walking the entire history before returning a single result.
Many Git users are using Git alongside a Git service that provides
code storage alongside a code review tool commonly called "Pull
Requests" or "Merge Requests" against a target branch. When these
requests are accepted and merged, they typically create a merge
commit whose first parent is the previous branch tip and the second
parent is the tip of the topic branch used for the request. This
presents a valuable order to the parents, but also makes that merge
commit slightly special. Users may want to see not only which
commits changed a file, but which pull requests merged those commits
into their branch. In the previous example, this would mean the
users want to see the merge commit "M" in addition to the single-
parent commit "C".
Users are even more likely to want these merge commits when they
use pull requests to merge into a feature branch before merging that
feature branch into their trunk.
In some sense, users are asking for the "first" merge commit to
bring in the change to their branch. As long as the parent order is
consistent, this can be handled with the following rule:
Include a merge commit if it is not TREESAME to its first
parent, but is TREESAME to a later parent.
These merges look like the merge commits that would result from
running "git pull <topic>" on a main branch. Thus, the option to
show these commits is called "--show-pulls". This has the added
benefit of showing the commits created by closing a pull request or
merge request on any of the Git hosting and code review platforms.
To test these options, extend the standard test example to include
a merge commit that is not TREESAME to its first parent. It is
surprising that that option was not already in the example, as it
is instructive.
In particular, this extension demonstrates a common issue with file
history simplification. When a user resolves a merge conflict using
"-Xours" or otherwise ignoring one side of the conflict, they create
a TREESAME edge that probably should not be TREESAME. This leads
users to become frustrated and complain that "my change disappeared!"
In my experience, showing them history with --full-history and
--simplify-merges quickly reveals the problematic merge. As mentioned,
this option is expensive to compute. The --show-pulls option
_might_ show the merge commit (usually titled "resolving conflicts")
more quickly. Of course, this depends on the user having the correct
parent order, which is backwards when using "git pull master" from a
topic branch.
There are some special considerations when combining the --show-pulls
option with --simplify-merges. This requires adding a new PULL_MERGE
object flag to store the information from the initial TREESAME
comparisons. This helps avoid dropping those commits in later filters.
This is covered by a test, including how the parents can be simplified.
Since "struct object" has already ruined its 32-bit alignment by using
33 bits across parsed, type, and flags member, let's not make it worse.
PULL_MERGE is used in revision.c with the same value (1u<<15) as
REACHABLE in commit-graph.c. The REACHABLE flag is only used when
writing a commit-graph file, and a revision walk using --show-pulls
does not happen in the same process. Care must be taken in the future
to ensure this remains the case.
Update Documentation/rev-list-options.txt with significant details
around this option. This requires updating the example in the
History Simplification section to demonstrate some of the problems
with TREESAME second parents.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 14:19:43 +02:00
|
|
|
treated as if it "pulled" the change from another branch. When using
|
|
|
|
`--show-pulls` on this example (and no other options) the resulting
|
|
|
|
graph is:
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
I---X---R---N
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
+
|
|
|
|
Here, the merge commits `R` and `N` are included because they pulled
|
|
|
|
the commits `X` and `R` into the base branch, respectively. These
|
|
|
|
merges are the reason the commits `A` and `B` do not appear in the
|
|
|
|
default history.
|
|
|
|
+
|
|
|
|
When `--show-pulls` is paired with `--simplify-merges`, the
|
|
|
|
graph includes all of the necessary information:
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
.-A---M--. N
|
|
|
|
/ / \ /
|
|
|
|
I B R
|
|
|
|
\ / /
|
|
|
|
\ / /
|
|
|
|
`---X--'
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
+
|
|
|
|
Notice that since `M` is reachable from `R`, the edge from `N` to `M`
|
|
|
|
was simplified away. However, `N` still appears in the history as an
|
|
|
|
important commit because it "pulled" the change `R` into the main
|
|
|
|
branch.
|
|
|
|
|
2013-11-15 02:34:01 +01:00
|
|
|
The `--simplify-by-decoration` option allows you to view only the
|
2008-11-10 10:58:17 +01:00
|
|
|
big picture of the topology of the history, by omitting commits
|
|
|
|
that are not referenced by tags. Commits are marked as !TREESAME
|
|
|
|
(in other words, kept after history simplification rules described
|
|
|
|
above) if (1) they are referenced by tags, or (2) they change the
|
|
|
|
contents of the paths given on the command line. All other
|
|
|
|
commits are marked as TREESAME (subject to be simplified away).
|
|
|
|
|
2019-11-08 20:26:27 +01:00
|
|
|
ifndef::git-shortlog[]
|
2008-01-18 23:58:57 +01:00
|
|
|
ifdef::git-rev-list[]
|
2008-08-12 01:55:36 +02:00
|
|
|
Bisection Helpers
|
|
|
|
~~~~~~~~~~~~~~~~~
|
|
|
|
|
2008-01-18 23:58:57 +01:00
|
|
|
--bisect::
|
2013-11-15 02:34:01 +01:00
|
|
|
Limit output to the one commit object which is roughly halfway between
|
|
|
|
included and excluded commits. Note that the bad bisection ref
|
|
|
|
`refs/bisect/bad` is added to the included commits (if it
|
|
|
|
exists) and the good bisection refs `refs/bisect/good-*` are
|
|
|
|
added to the excluded commits (if they exist). Thus, supposing there
|
|
|
|
are no refs in `refs/bisect/`, if
|
|
|
|
+
|
2008-01-18 23:58:57 +01:00
|
|
|
-----------------------------------------------------------------------
|
2008-11-09 14:46:35 +01:00
|
|
|
$ git rev-list --bisect foo ^bar ^baz
|
2008-01-18 23:58:57 +01:00
|
|
|
-----------------------------------------------------------------------
|
2013-11-15 02:34:01 +01:00
|
|
|
+
|
2008-01-18 23:58:57 +01:00
|
|
|
outputs 'midpoint', the output of the two commands
|
2013-11-15 02:34:01 +01:00
|
|
|
+
|
2008-01-18 23:58:57 +01:00
|
|
|
-----------------------------------------------------------------------
|
2008-11-09 14:46:35 +01:00
|
|
|
$ git rev-list foo ^midpoint
|
|
|
|
$ git rev-list midpoint ^bar ^baz
|
2008-01-18 23:58:57 +01:00
|
|
|
-----------------------------------------------------------------------
|
2013-11-15 02:34:01 +01:00
|
|
|
+
|
2008-01-18 23:58:57 +01:00
|
|
|
would be of roughly the same length. Finding the change which
|
|
|
|
introduces a regression is thus reduced to a binary search: repeatedly
|
|
|
|
generate and test new 'midpoint's until the commit chain is of length
|
2020-08-07 23:58:35 +02:00
|
|
|
one.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
|
|
|
--bisect-vars::
|
2013-11-15 02:34:01 +01:00
|
|
|
This calculates the same as `--bisect`, except that refs in
|
|
|
|
`refs/bisect/` are not used, and except that this outputs
|
|
|
|
text ready to be eval'ed by the shell. These lines will assign the
|
|
|
|
name of the midpoint revision to the variable `bisect_rev`, and the
|
|
|
|
expected number of commits to be tested after `bisect_rev` is tested
|
|
|
|
to `bisect_nr`, the expected number of commits to be tested if
|
|
|
|
`bisect_rev` turns out to be good to `bisect_good`, the expected
|
|
|
|
number of commits to be tested if `bisect_rev` turns out to be bad to
|
|
|
|
`bisect_bad`, and the number of commits we are bisecting right now to
|
|
|
|
`bisect_all`.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
|
|
|
--bisect-all::
|
2013-11-15 02:34:01 +01:00
|
|
|
This outputs all the commit objects between the included and excluded
|
|
|
|
commits, ordered by their distance to the included and excluded
|
|
|
|
commits. Refs in `refs/bisect/` are not used. The farthest
|
|
|
|
from them is displayed first. (This is the only one displayed by
|
|
|
|
`--bisect`.)
|
2009-03-07 13:37:24 +01:00
|
|
|
+
|
2008-01-18 23:58:57 +01:00
|
|
|
This is useful because it makes it easy to choose a good commit to
|
|
|
|
test when you want to avoid to test some of them for some reason (they
|
|
|
|
may not compile for example).
|
2009-03-07 13:37:24 +01:00
|
|
|
+
|
2008-01-18 23:58:57 +01:00
|
|
|
This option can be used along with `--bisect-vars`, in this case,
|
|
|
|
after all the sorted commit objects, there will be the same text as if
|
|
|
|
`--bisect-vars` had been used alone.
|
|
|
|
endif::git-rev-list[]
|
2019-11-08 20:26:27 +01:00
|
|
|
endif::git-shortlog[]
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2019-11-08 20:26:27 +01:00
|
|
|
ifndef::git-shortlog[]
|
2008-01-18 23:58:57 +01:00
|
|
|
Commit Ordering
|
|
|
|
~~~~~~~~~~~~~~~
|
|
|
|
|
|
|
|
By default, the commits are shown in reverse chronological order.
|
|
|
|
|
2012-08-15 22:02:48 +02:00
|
|
|
--date-order::
|
|
|
|
Show no parents before all of its children are shown, but
|
|
|
|
otherwise show commits in the commit timestamp order.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2013-06-07 19:35:54 +02:00
|
|
|
--author-date-order::
|
|
|
|
Show no parents before all of its children are shown, but
|
|
|
|
otherwise show commits in the author timestamp order.
|
|
|
|
|
2012-08-15 22:02:48 +02:00
|
|
|
--topo-order::
|
|
|
|
Show no parents before all of its children are shown, and
|
|
|
|
avoid showing commits on multiple lines of history
|
|
|
|
intermixed.
|
|
|
|
+
|
|
|
|
For example, in a commit history like this:
|
|
|
|
+
|
|
|
|
----------------------------------------------------------------
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2012-08-15 22:02:48 +02:00
|
|
|
---1----2----4----7
|
|
|
|
\ \
|
|
|
|
3----5----6----8---
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2012-08-15 22:02:48 +02:00
|
|
|
----------------------------------------------------------------
|
|
|
|
+
|
|
|
|
where the numbers denote the order of commit timestamps, `git
|
|
|
|
rev-list` and friends with `--date-order` show the commits in the
|
|
|
|
timestamp order: 8 7 6 5 4 3 2 1.
|
|
|
|
+
|
|
|
|
With `--topo-order`, they would show 8 6 5 3 7 4 2 1 (or 8 7 4 2 6 5
|
|
|
|
3 1); some older commits are shown before newer ones in order to
|
|
|
|
avoid showing the commits from two parallel development track mixed
|
|
|
|
together.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
|
|
|
--reverse::
|
2016-09-27 22:44:09 +02:00
|
|
|
Output the commits chosen to be shown (see Commit Limiting
|
|
|
|
section above) in reverse order. Cannot be combined with
|
|
|
|
`--walk-reflogs`.
|
2019-11-08 20:26:27 +01:00
|
|
|
endif::git-shortlog[]
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2019-11-08 20:26:27 +01:00
|
|
|
ifndef::git-shortlog[]
|
2008-01-18 23:58:57 +01:00
|
|
|
Object Traversal
|
|
|
|
~~~~~~~~~~~~~~~~
|
|
|
|
|
2013-01-21 20:17:53 +01:00
|
|
|
These options are mostly targeted for packing of Git repositories.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2015-01-23 20:49:05 +01:00
|
|
|
ifdef::git-rev-list[]
|
2008-01-18 23:58:57 +01:00
|
|
|
--objects::
|
|
|
|
Print the object IDs of any object referenced by the listed
|
2013-11-15 02:34:01 +01:00
|
|
|
commits. `--objects foo ^bar` thus means ``send me
|
2008-01-18 23:58:57 +01:00
|
|
|
all object IDs which I need to download if I have the commit
|
2013-11-15 02:34:01 +01:00
|
|
|
object _bar_ but not _foo_''.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2017-11-16 03:00:35 +01:00
|
|
|
--in-commit-order::
|
|
|
|
Print tree and blob ids in order of the commits. The tree
|
|
|
|
and blob ids are printed after they are first referenced
|
|
|
|
by a commit.
|
|
|
|
|
2008-01-18 23:58:57 +01:00
|
|
|
--objects-edge::
|
2013-11-15 02:34:01 +01:00
|
|
|
Similar to `--objects`, but also print the IDs of excluded
|
|
|
|
commits prefixed with a ``-'' character. This is used by
|
2014-12-20 23:51:11 +01:00
|
|
|
linkgit:git-pack-objects[1] to build a ``thin'' pack, which records
|
2008-01-18 23:58:57 +01:00
|
|
|
objects in deltified form based on objects contained in these
|
|
|
|
excluded commits to reduce network traffic.
|
|
|
|
|
2014-12-25 00:05:39 +01:00
|
|
|
--objects-edge-aggressive::
|
|
|
|
Similar to `--objects-edge`, but it tries harder to find excluded
|
2014-12-25 00:05:40 +01:00
|
|
|
commits at the cost of increased time. This is used instead of
|
|
|
|
`--objects-edge` to build ``thin'' packs for shallow repositories.
|
2014-12-25 00:05:39 +01:00
|
|
|
|
2015-01-23 20:49:05 +01:00
|
|
|
--indexed-objects::
|
|
|
|
Pretend as if all trees and blobs used by the index are listed
|
|
|
|
on the command line. Note that you probably want to use
|
|
|
|
`--objects`, too.
|
|
|
|
|
2008-01-18 23:58:57 +01:00
|
|
|
--unpacked::
|
2013-11-15 02:34:01 +01:00
|
|
|
Only useful with `--objects`; print the object IDs that are not
|
2008-01-18 23:58:57 +01:00
|
|
|
in packs.
|
2017-11-21 21:58:51 +01:00
|
|
|
|
2019-06-19 22:56:56 +02:00
|
|
|
--object-names::
|
|
|
|
Only useful with `--objects`; print the names of the object IDs
|
|
|
|
that are found. This is the default behavior.
|
|
|
|
|
|
|
|
--no-object-names::
|
|
|
|
Only useful with `--objects`; does not print the names of the object
|
|
|
|
IDs that are found. This inverts `--object-names`. This flag allows
|
|
|
|
the output to be more easily parsed by commands such as
|
|
|
|
linkgit:git-cat-file[1].
|
|
|
|
|
2017-11-21 21:58:51 +01:00
|
|
|
--filter=<filter-spec>::
|
|
|
|
Only useful with one of the `--objects*`; omits objects (usually
|
|
|
|
blobs) from the list of printed objects. The '<filter-spec>'
|
|
|
|
may be one of the following:
|
|
|
|
+
|
|
|
|
The form '--filter=blob:none' omits all blobs.
|
|
|
|
+
|
|
|
|
The form '--filter=blob:limit=<n>[kmg]' omits blobs larger than n bytes
|
2017-12-05 17:50:14 +01:00
|
|
|
or units. n may be zero. The suffixes k, m, and g can be used to name
|
|
|
|
units in KiB, MiB, or GiB. For example, 'blob:limit=1k' is the same
|
|
|
|
as 'blob:limit=1024'.
|
2017-11-21 21:58:51 +01:00
|
|
|
+
|
2021-04-19 13:46:53 +02:00
|
|
|
The form '--filter=object:type=(tag|commit|tree|blob)' omits all objects
|
|
|
|
which are not of the requested type.
|
|
|
|
+
|
2017-12-05 17:50:14 +01:00
|
|
|
The form '--filter=sparse:oid=<blob-ish>' uses a sparse-checkout
|
|
|
|
specification contained in the blob (or blob-expression) '<blob-ish>'
|
2021-07-14 00:31:26 +02:00
|
|
|
to omit blobs that would not be required for a sparse checkout on
|
2017-12-05 17:50:14 +01:00
|
|
|
the requested refs.
|
2017-11-21 21:58:51 +01:00
|
|
|
+
|
2018-10-05 23:31:27 +02:00
|
|
|
The form '--filter=tree:<depth>' omits all blobs and trees whose depth
|
|
|
|
from the root tree is >= <depth> (minimum depth if an object is located
|
2019-01-09 03:59:13 +01:00
|
|
|
at multiple depths in the commits traversed). <depth>=0 will not include
|
|
|
|
any trees or blobs unless included explicitly in the command-line (or
|
|
|
|
standard input when --stdin is used). <depth>=1 will include only the
|
|
|
|
tree and blobs which are referenced directly by a commit reachable from
|
|
|
|
<commit> or an explicitly-given object. <depth>=2 is like <depth>=1
|
|
|
|
while also including trees and blobs one more level removed from an
|
|
|
|
explicitly-given commit or tree.
|
2019-05-29 14:44:32 +02:00
|
|
|
+
|
|
|
|
Note that the form '--filter=sparse:path=<path>' that wants to read
|
|
|
|
from an arbitrary path on the filesystem has been dropped for security
|
|
|
|
reasons.
|
2019-06-28 00:54:12 +02:00
|
|
|
+
|
|
|
|
Multiple '--filter=' flags can be specified to combine filters. Only
|
|
|
|
objects which are accepted by every filter are included.
|
|
|
|
+
|
|
|
|
The form '--filter=combine:<filter1>+<filter2>+...<filterN>' can also be
|
|
|
|
used to combined several filters, but this is harder than just repeating
|
|
|
|
the '--filter' flag and is usually not necessary. Filters are joined by
|
|
|
|
'{plus}' and individual filters are %-encoded (i.e. URL-encoded).
|
|
|
|
Besides the '{plus}' and '%' characters, the following characters are
|
|
|
|
reserved and also must be encoded: `~!@#$^&*()[]{}\;",<>?`+'`+
|
|
|
|
as well as all characters with ASCII code <= `0x20`, which includes
|
|
|
|
space and newline.
|
|
|
|
+
|
|
|
|
Other arbitrary characters can also be encoded. For instance,
|
|
|
|
'combine:tree:3+blob:none' and 'combine:tree%3A3+blob%3Anone' are
|
|
|
|
equivalent.
|
2017-11-21 21:58:51 +01:00
|
|
|
|
2017-12-05 17:50:14 +01:00
|
|
|
--no-filter::
|
|
|
|
Turn off any previous `--filter=` argument.
|
|
|
|
|
2021-04-19 13:47:06 +02:00
|
|
|
--filter-provided-objects::
|
|
|
|
Filter the list of explicitly provided objects, which would otherwise
|
|
|
|
always be printed even if they did not match any of the filters. Only
|
|
|
|
useful with `--filter=`.
|
|
|
|
|
2017-11-21 21:58:51 +01:00
|
|
|
--filter-print-omitted::
|
|
|
|
Only useful with `--filter=`; prints a list of the objects omitted
|
2019-03-06 07:30:18 +01:00
|
|
|
by the filter. Object IDs are prefixed with a ``~'' character.
|
2017-11-21 21:58:51 +01:00
|
|
|
|
|
|
|
--missing=<missing-action>::
|
|
|
|
A debug option to help with future "partial clone" development.
|
|
|
|
This option specifies how missing objects are handled.
|
|
|
|
+
|
|
|
|
The form '--missing=error' requests that rev-list stop with an error if
|
|
|
|
a missing object is encountered. This is the default action.
|
|
|
|
+
|
|
|
|
The form '--missing=allow-any' will allow object traversal to continue
|
|
|
|
if a missing object is encountered. Missing objects will silently be
|
|
|
|
omitted from the results.
|
|
|
|
+
|
2017-12-08 16:27:15 +01:00
|
|
|
The form '--missing=allow-promisor' is like 'allow-any', but will only
|
|
|
|
allow object traversal to continue for EXPECTED promisor missing objects.
|
|
|
|
Unexpected missing objects will raise an error.
|
|
|
|
+
|
2017-11-21 21:58:51 +01:00
|
|
|
The form '--missing=print' is like 'allow-any', but will also print a
|
|
|
|
list of the missing objects. Object IDs are prefixed with a ``?'' character.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
2017-12-08 16:27:15 +01:00
|
|
|
--exclude-promisor-objects::
|
|
|
|
(For internal use only.) Prefilter object traversal at
|
|
|
|
promisor boundary. This is used with partial clone. This is
|
|
|
|
stronger than `--missing=allow-promisor` because it limits the
|
|
|
|
traversal, rather than just silencing errors about missing
|
|
|
|
objects.
|
2018-10-23 03:13:41 +02:00
|
|
|
endif::git-rev-list[]
|
2017-12-08 16:27:15 +01:00
|
|
|
|
teach log --no-walk=unsorted, which avoids sorting
When 'git log' is passed the --no-walk option, no revision walk takes
place, naturally. Perhaps somewhat surprisingly, however, the provided
revisions still get sorted by commit date. So e.g 'git log --no-walk
HEAD HEAD~1' and 'git log --no-walk HEAD~1 HEAD' give the same result
(unless the two revisions share the commit date, in which case they
will retain the order given on the command line). As the commit that
introduced --no-walk (8e64006 (Teach revision machinery about
--no-walk, 2007-07-24)) points out, the sorting is intentional, to
allow things like
git log --abbrev-commit --pretty=oneline --decorate --all --no-walk
to show all refs in order by commit date.
But there are also other cases where the sorting is not wanted, such
as
<command producing revisions in order> |
git log --oneline --no-walk --stdin
To accomodate both cases, leave the decision of whether or not to sort
up to the caller, by allowing --no-walk={sorted,unsorted}, defaulting
to 'sorted' for backward-compatibility reasons.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-29 08:15:54 +02:00
|
|
|
--no-walk[=(sorted|unsorted)]::
|
|
|
|
Only show the given commits, but do not traverse their ancestors.
|
|
|
|
This has no effect if a range is specified. If the argument
|
2013-11-15 02:34:02 +01:00
|
|
|
`unsorted` is given, the commits are shown in the order they were
|
2013-11-15 02:34:01 +01:00
|
|
|
given on the command line. Otherwise (if `sorted` or no argument
|
2013-11-15 02:34:02 +01:00
|
|
|
was given), the commits are shown in reverse chronological order
|
teach log --no-walk=unsorted, which avoids sorting
When 'git log' is passed the --no-walk option, no revision walk takes
place, naturally. Perhaps somewhat surprisingly, however, the provided
revisions still get sorted by commit date. So e.g 'git log --no-walk
HEAD HEAD~1' and 'git log --no-walk HEAD~1 HEAD' give the same result
(unless the two revisions share the commit date, in which case they
will retain the order given on the command line). As the commit that
introduced --no-walk (8e64006 (Teach revision machinery about
--no-walk, 2007-07-24)) points out, the sorting is intentional, to
allow things like
git log --abbrev-commit --pretty=oneline --decorate --all --no-walk
to show all refs in order by commit date.
But there are also other cases where the sorting is not wanted, such
as
<command producing revisions in order> |
git log --oneline --no-walk --stdin
To accomodate both cases, leave the decision of whether or not to sort
up to the caller, by allowing --no-walk={sorted,unsorted}, defaulting
to 'sorted' for backward-compatibility reasons.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-29 08:15:54 +02:00
|
|
|
by commit time.
|
2021-11-11 21:34:41 +01:00
|
|
|
Cannot be combined with `--graph`.
|
2008-01-18 23:58:57 +01:00
|
|
|
|
|
|
|
--do-walk::
|
2013-11-15 02:34:01 +01:00
|
|
|
Overrides a previous `--no-walk`.
|
2019-11-08 20:26:27 +01:00
|
|
|
endif::git-shortlog[]
|
2011-03-08 09:31:26 +01:00
|
|
|
|
2019-11-08 20:26:27 +01:00
|
|
|
ifndef::git-shortlog[]
|
2011-03-08 09:31:26 +01:00
|
|
|
Commit Formatting
|
|
|
|
~~~~~~~~~~~~~~~~~
|
|
|
|
|
|
|
|
ifdef::git-rev-list[]
|
|
|
|
Using these options, linkgit:git-rev-list[1] will act similar to the
|
|
|
|
more specialized family of commit log tools: linkgit:git-log[1],
|
|
|
|
linkgit:git-show[1], and linkgit:git-whatchanged[1]
|
|
|
|
endif::git-rev-list[]
|
|
|
|
|
|
|
|
include::pretty-options.txt[]
|
|
|
|
|
|
|
|
--relative-date::
|
|
|
|
Synonym for `--date=relative`.
|
|
|
|
|
2015-09-03 23:48:54 +02:00
|
|
|
--date=<format>::
|
2011-03-08 09:31:26 +01:00
|
|
|
Only takes effect for dates shown in human-readable format, such
|
2013-11-15 02:34:01 +01:00
|
|
|
as when using `--pretty`. `log.date` config variable sets a default
|
2015-09-03 23:48:59 +02:00
|
|
|
value for the log command's `--date` option. By default, dates
|
|
|
|
are shown in the original time zone (either committer's or
|
|
|
|
author's). If `-local` is appended to the format (e.g.,
|
|
|
|
`iso-local`), the user's local time zone is used instead.
|
2011-03-08 09:31:26 +01:00
|
|
|
+
|
2019-03-30 19:30:00 +01:00
|
|
|
--
|
2011-03-08 09:31:26 +01:00
|
|
|
`--date=relative` shows dates relative to the current time,
|
date: document and test "raw-local" mode
The "raw" format shows a Unix epoch timestamp, but with a
timezone tacked on. The timestamp is not _in_ that zone, but
it is extra information about the time (by default, the zone
the author was in).
The documentation claims that "raw-local" does not work. It
does, but the end result is rather subtle. Let's describe it
in better detail, and test to make sure it works (namely,
the epoch time doesn't change, but the zone does).
While we are rewording the documentation in this area, let's
not use the phrase "does not work" for the remaining option,
"--date=relative". It's vague; do we accept it or not? We do
accept it, but it has no effect (which is a reasonable
outcome). We should also refer to the option not as
"--relative" (which is the historical synonym, and does not
take "-local" at all), but as "--date=relative".
Helped-by: Jakub Narębski <jnareb@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-27 15:44:41 +02:00
|
|
|
e.g. ``2 hours ago''. The `-local` option has no effect for
|
|
|
|
`--date=relative`.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2015-09-03 23:48:59 +02:00
|
|
|
`--date=local` is an alias for `--date=default-local`.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2014-08-29 18:58:42 +02:00
|
|
|
`--date=iso` (or `--date=iso8601`) shows timestamps in a ISO 8601-like format.
|
|
|
|
The differences to the strict ISO 8601 format are:
|
|
|
|
|
|
|
|
- a space instead of the `T` date/time delimiter
|
|
|
|
- a space between time and time zone
|
|
|
|
- no colon between hours and minutes of the time zone
|
|
|
|
|
|
|
|
`--date=iso-strict` (or `--date=iso8601-strict`) shows timestamps in strict
|
|
|
|
ISO 8601 format.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2011-03-08 09:31:26 +01:00
|
|
|
`--date=rfc` (or `--date=rfc2822`) shows timestamps in RFC 2822
|
2013-11-15 02:34:02 +01:00
|
|
|
format, often found in email messages.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2013-11-15 02:34:02 +01:00
|
|
|
`--date=short` shows only the date, but not the time, in `YYYY-MM-DD` format.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2016-07-27 22:07:29 +02:00
|
|
|
`--date=raw` shows the date as seconds since the epoch (1970-01-01
|
|
|
|
00:00:00 UTC), followed by a space, and then the timezone as an offset
|
|
|
|
from UTC (a `+` or `-` with four digits; the first two are hours, and
|
|
|
|
the second two are minutes). I.e., as if the timestamp were formatted
|
|
|
|
with `strftime("%s %z")`).
|
date: document and test "raw-local" mode
The "raw" format shows a Unix epoch timestamp, but with a
timezone tacked on. The timestamp is not _in_ that zone, but
it is extra information about the time (by default, the zone
the author was in).
The documentation claims that "raw-local" does not work. It
does, but the end result is rather subtle. Let's describe it
in better detail, and test to make sure it works (namely,
the epoch time doesn't change, but the zone does).
While we are rewording the documentation in this area, let's
not use the phrase "does not work" for the remaining option,
"--date=relative". It's vague; do we accept it or not? We do
accept it, but it has no effect (which is a reasonable
outcome). We should also refer to the option not as
"--relative" (which is the historical synonym, and does not
take "-local" at all), but as "--date=relative".
Helped-by: Jakub Narębski <jnareb@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-27 15:44:41 +02:00
|
|
|
Note that the `-local` option does not affect the seconds-since-epoch
|
|
|
|
value (which is always measured in UTC), but does switch the accompanying
|
|
|
|
timezone value.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2019-01-21 06:31:10 +01:00
|
|
|
`--date=human` shows the timezone if the timezone does not match the
|
|
|
|
current time-zone, and doesn't print the whole date if that matches
|
|
|
|
(ie skip printing year for dates that are "this year", but also skip
|
|
|
|
the whole date itself if it's in the last few days and we can just say
|
|
|
|
what weekday it was). For older dates the hour and minute is also
|
|
|
|
omitted.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2016-07-22 21:51:49 +02:00
|
|
|
`--date=unix` shows the date as a Unix epoch timestamp (seconds since
|
|
|
|
1970). As with `--raw`, this is always in UTC and therefore `-local`
|
|
|
|
has no effect.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2017-06-15 14:29:53 +02:00
|
|
|
`--date=format:...` feeds the format `...` to your system `strftime`,
|
strbuf_addftime(): handle "%s" manually
The strftime() function has a non-standard "%s" extension, which prints
the number of seconds since the epoch. But the "struct tm" we get has
already been adjusted for a particular time zone; going back to an epoch
time requires knowing that zone offset. Since strftime() doesn't take
such an argument, round-tripping to a "struct tm" and back to the "%s"
format may produce the wrong value (off by tz_offset seconds).
Since we're already passing in the zone offset courtesy of c3fbf81a85
(strbuf: let strbuf_addftime handle %z and %Z itself, 2017-06-15), we
can use that same value to adjust our epoch seconds accordingly.
Note that the description above makes it sound like strftime()'s "%s" is
useless (and really, the issue is shared by mktime(), which is what
strftime() would use under the hood). But it gets the two cases for
which it's designed correct:
- the result of gmtime() will have a zero offset, so no adjustment is
necessary
- the result of localtime() will be offset by the local zone offset,
and mktime() and strftime() are defined to assume this offset when
converting back (there's actually some magic here; some
implementations record this in the "struct tm", but we can't
portably access or manipulate it. But they somehow "know" whether a
"struct tm" is from gmtime() or localtime()).
This latter point means that "format-local:%s" actually works correctly
already, because in that case we rely on the system routines due to
6eced3ec5e (date: use localtime() for "-local" time formats,
2017-06-15). Our problem comes when trying to show times in the author's
zone, as the system routines provide no mechanism for converting in
non-local zones. So in those cases we have a "struct tm" that came from
gmtime(), but has been manipulated according to our offset.
The tests cover the broken round-trip by formatting "%s" for a time in a
non-system timezone. We use the made-up "+1234" here, which has two
advantages. One, we know it won't ever be the real system zone (and so
we're actually testing a case that would break). And two, since it has a
minute component, we're testing the full decoding of the +HHMM zone into
a number of seconds. Likewise, we test the "-1234" variant to make sure
there aren't any sign mistakes.
There's one final test, which covers "format-local:%s". As noted, this
already passes, but it's important to check that we didn't regress this
case. In particular, the caller in show_date() is relying on localtime()
to have done the zone adjustment, independent of any tz_offset we
compute ourselves. These should match up, since our local_tzoffset() is
likewise built around localtime(). But it would be easy for a caller to
forget to pass in a correct tz_offset to strbuf_addftime(). Fortunately
show_date() does this correctly (it has to because of the existing
handling of %z), and the test continues to pass. So this one is just
future-proofing against a change in our assumptions.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-02 12:35:34 +01:00
|
|
|
except for %s, %z, and %Z, which are handled internally.
|
2015-06-25 18:55:45 +02:00
|
|
|
Use `--date=format:%c` to show the date in your system locale's
|
|
|
|
preferred format. See the `strftime` manual for a complete list of
|
2015-09-03 23:48:59 +02:00
|
|
|
format placeholders. When using `-local`, the correct syntax is
|
|
|
|
`--date=format-local:...`.
|
2019-03-30 19:30:00 +01:00
|
|
|
|
2015-09-03 23:48:59 +02:00
|
|
|
`--date=default` is the default format, and is similar to
|
|
|
|
`--date=rfc2822`, with a few exceptions:
|
2019-03-30 19:30:00 +01:00
|
|
|
--
|
2015-09-03 23:48:59 +02:00
|
|
|
- there is no comma after the day-of-week
|
|
|
|
|
|
|
|
- the time zone is omitted when the local time zone is used
|
2011-03-08 09:31:26 +01:00
|
|
|
|
|
|
|
ifdef::git-rev-list[]
|
|
|
|
--header::
|
|
|
|
Print the contents of the commit in raw-format; each record is
|
|
|
|
separated with a NUL character.
|
rev-list: add option for --pretty=format without header
In general, we encourage users to use plumbing commands, like git
rev-list, over porcelain commands, like git log, when scripting.
However, git rev-list has one glaring problem that prevents it from
being used in certain cases: when --pretty is used with a custom format,
it always prints out a line containing "commit" and the object ID. This
makes it unsuitable for many scripting needs, and forces users to use
git log instead.
While we can't change this behavior for backwards compatibility, we can
add an option to suppress this behavior, so let's do so, and call it
"--no-commit-header". Additionally, add the corresponding positive
option to switch it back on.
Note that this option doesn't affect the built-in formats, only custom
formats. This is exactly the same behavior as users already have from
git log and is what most users will be used to.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-11 23:55:10 +02:00
|
|
|
|
|
|
|
--no-commit-header::
|
|
|
|
Suppress the header line containing "commit" and the object ID printed before
|
|
|
|
the specified format. This has no effect on the built-in formats; only custom
|
|
|
|
formats are affected.
|
|
|
|
|
|
|
|
--commit-header::
|
|
|
|
Overrides a previous `--no-commit-header`.
|
2011-03-08 09:31:26 +01:00
|
|
|
endif::git-rev-list[]
|
|
|
|
|
|
|
|
--parents::
|
|
|
|
Print also the parents of the commit (in the form "commit parent...").
|
2017-10-26 17:26:37 +02:00
|
|
|
Also enables parent rewriting, see 'History Simplification' above.
|
2011-03-08 09:31:26 +01:00
|
|
|
|
|
|
|
--children::
|
|
|
|
Print also the children of the commit (in the form "commit child...").
|
2017-10-26 17:26:37 +02:00
|
|
|
Also enables parent rewriting, see 'History Simplification' above.
|
2011-03-08 09:31:26 +01:00
|
|
|
|
|
|
|
ifdef::git-rev-list[]
|
|
|
|
--timestamp::
|
|
|
|
Print the raw commit timestamp.
|
|
|
|
endif::git-rev-list[]
|
|
|
|
|
|
|
|
--left-right::
|
2016-07-20 23:10:00 +02:00
|
|
|
Mark which side of a symmetric difference a commit is reachable from.
|
2011-03-08 09:31:26 +01:00
|
|
|
Commits from the left side are prefixed with `<` and those from
|
|
|
|
the right with `>`. If combined with `--boundary`, those
|
|
|
|
commits are prefixed with `-`.
|
|
|
|
+
|
|
|
|
For example, if you have this topology:
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
y---b---b branch B
|
|
|
|
/ \ /
|
|
|
|
/ .
|
|
|
|
/ / \
|
|
|
|
o---x---a---a branch A
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
+
|
|
|
|
you would get an output like this:
|
|
|
|
+
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
$ git rev-list --left-right --boundary --pretty=oneline A...B
|
|
|
|
|
|
|
|
>bbbbbbb... 3rd on b
|
|
|
|
>bbbbbbb... 2nd on b
|
|
|
|
<aaaaaaa... 3rd on a
|
|
|
|
<aaaaaaa... 2nd on a
|
|
|
|
-yyyyyyy... 1st on b
|
|
|
|
-xxxxxxx... 1st on a
|
|
|
|
-----------------------------------------------------------------------
|
|
|
|
|
|
|
|
--graph::
|
|
|
|
Draw a text-based graphical representation of the commit history
|
|
|
|
on the left hand side of the output. This may cause extra lines
|
|
|
|
to be printed in between commits, in order for the graph history
|
|
|
|
to be drawn properly.
|
2015-03-11 03:13:02 +01:00
|
|
|
Cannot be combined with `--no-walk`.
|
2011-03-08 09:31:26 +01:00
|
|
|
+
|
2017-10-26 17:26:37 +02:00
|
|
|
This enables parent rewriting, see 'History Simplification' above.
|
2011-03-08 09:31:26 +01:00
|
|
|
+
|
2013-11-15 02:34:01 +01:00
|
|
|
This implies the `--topo-order` option by default, but the
|
|
|
|
`--date-order` option may also be specified.
|
2011-03-08 09:31:26 +01:00
|
|
|
|
2014-03-25 14:23:27 +01:00
|
|
|
--show-linear-break[=<barrier>]::
|
|
|
|
When --graph is not used, all history branches are flattened
|
|
|
|
which can make it hard to see that the two consecutive commits
|
|
|
|
do not belong to a linear branch. This option puts a barrier
|
|
|
|
in between them in that case. If `<barrier>` is specified, it
|
|
|
|
is the string that will be shown instead of the default one.
|
|
|
|
|
2011-03-08 09:31:26 +01:00
|
|
|
ifdef::git-rev-list[]
|
|
|
|
--count::
|
|
|
|
Print a number stating how many commits would have been
|
|
|
|
listed, and suppress all other output. When used together
|
2013-11-15 02:34:01 +01:00
|
|
|
with `--left-right`, instead print the counts for left and
|
2011-04-26 10:24:29 +02:00
|
|
|
right commits, separated by a tab. When used together with
|
2013-11-15 02:34:01 +01:00
|
|
|
`--cherry-mark`, omit patch equivalent commits from these
|
2011-04-26 10:24:29 +02:00
|
|
|
counts and print the count for equivalent commits separated
|
|
|
|
by a tab.
|
2011-03-08 09:31:26 +01:00
|
|
|
endif::git-rev-list[]
|
2019-11-08 20:26:27 +01:00
|
|
|
endif::git-shortlog[]
|