Commit Graph

637 Commits

Author SHA1 Message Date
Junio C Hamano
d6d561db1c Merge branch 'jt/rebase-allow-duplicate'
Allow "git rebase" to reapply all local commits, even if the may be
already in the upstream, without checking first.

* jt/rebase-allow-duplicate:
  rebase --merge: optionally skip upstreamed commits
2020-04-22 13:43:00 -07:00
Junio C Hamano
c7d8f69da5 Merge branch 'en/rebase-no-keep-empty'
"git rebase" (again) learns to honor "--no-keep-empty", which lets
the user to discard commits that are empty from the beginning (as
opposed to the ones that become empty because of rebasing).  The
interactive rebase also marks commits that are empty in the todo.

* en/rebase-no-keep-empty:
  rebase: fix an incompatible-options error message
  rebase: reinstate --no-keep-empty
  rebase -i: mark commits that begin empty in todo editor
2020-04-22 13:43:00 -07:00
Junio C Hamano
fc3f6fd7be Merge branch 'dd/no-gpg-sign'
"git rebase" learned the "--no-gpg-sign" option to countermand
commit.gpgSign the user may have.

* dd/no-gpg-sign:
  Documentation: document merge option --no-gpg-sign
  Documentation: merge commit-tree --[no-]gpg-sign
  Documentation: reword commit --no-gpg-sign
  Documentation: document am --no-gpg-sign
  cherry-pick/revert: honour --no-gpg-sign in all case
  rebase.c: honour --no-gpg-sign
2020-04-22 13:42:53 -07:00
Junio C Hamano
3aa30ccb1c Merge branch 'en/sequencer-reflog-action'
"git rebase -i" did not leave the reflog entries correctly.

* en/sequencer-reflog-action:
  sequencer: honor GIT_REFLOG_ACTION
2020-04-22 13:42:51 -07:00
Junio C Hamano
f72e06703b Merge branch 'ag/rebase-merge-allow-ff-under-abbrev-command'
"git rebase" with the merge backend did not work well when the
rebase.abbreviateCommands configuration was set.

* ag/rebase-merge-allow-ff-under-abbrev-command:
  t3432: test `--merge' with `rebase.abbreviateCommands = true', too
  sequencer: don't abbreviate a command if it doesn't have a short form
2020-04-22 13:42:50 -07:00
Jonathan Tan
0fcb4f6b62 rebase --merge: optionally skip upstreamed commits
When rebasing against an upstream that has had many commits since the
original branch was created:

 O -- O -- ... -- O -- O (upstream)
  \
   -- O (my-dev-branch)

it must read the contents of every novel upstream commit, in addition to
the tip of the upstream and the merge base, because "git rebase"
attempts to exclude commits that are duplicates of upstream ones. This
can be a significant performance hit, especially in a partial clone,
wherein a read of an object may end up being a fetch.

Add a flag to "git rebase" to allow suppression of this feature. This
flag only works when using the "merge" backend.

This flag changes the behavior of sequencer_make_script(), called from
do_interactive_rebase() <- run_rebase_interactive() <-
run_specific_rebase() <- cmd_rebase(). With this flag, limit_list()
(indirectly called from sequencer_make_script() through
prepare_revision_walk()) will no longer call cherry_pick_list(), and
thus PATCHSAME is no longer set. Refraining from setting PATCHSAME both
means that the intermediate commits in upstream are no longer read (as
shown by the test) and means that no PATCHSAME-caused skipping of
commits is done by sequencer_make_script(), either directly or through
make_script_with_merges().

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-11 14:15:57 -07:00
Elijah Newren
b9cbd2958f rebase: reinstate --no-keep-empty
Commit d48e5e21da ("rebase (interactive-backend): make --keep-empty the
default", 2020-02-15) turned --keep-empty (for keeping commits which
start empty) into the default.  The logic underpinning that commit was:

  1) 'git commit' errors out on the creation of empty commits without an
     override flag
  2) Once someone determines that the override is worthwhile, it's
     annoying and/or harmful to required them to take extra steps in
     order to keep such commits around (and to repeat such steps with
     every rebase).

While the logic on which the decision was made is sound, the result was
a bit of an overcorrection.  Instead of jumping to having --keep-empty
being the default, it jumped to making --keep-empty the only available
behavior.  There was a simple workaround, though, which was thought to
be good enough at the time.  People could still drop commits which
started empty the same way the could drop any commits: by firing up an
interactive rebase and picking out the commits they didn't want from the
list.  However, there are cases where external tools might create enough
empty commits that picking all of them out is painful.  As such, having
a flag to automatically remove start-empty commits may be beneficial.

Provide users a way to drop commits which start empty using a flag that
existed for years: --no-keep-empty.  Interpret --keep-empty as
countermanding any previous --no-keep-empty, but otherwise leaving
--keep-empty as the default.

This might lead to some slight weirdness since commands like
  git rebase --empty=drop --keep-empty
  git rebase --empty=keep --no-keep-empty
look really weird despite making perfect sense (the first will drop
commits which become empty, but keep commits that started empty; the
second will keep commits which become empty, but drop commits which
started empty).  However, --no-keep-empty was named years ago and we are
predominantly keeping it for backward compatibility; also we suspect it
will only be used rarely since folks already have a simple way to drop
commits they don't want with an interactive rebase.

Reported-by: Bryan Turner <bturner@atlassian.com>
Reported-by: Sami Boukortt <sami@boukortt.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-11 14:15:52 -07:00
Elijah Newren
1b5735f75c rebase -i: mark commits that begin empty in todo editor
While many users who intentionally create empty commits do not want them
thrown away by a rebase, there are third-party tools that generate empty
commits that a user might not want.  In the past, users have used rebase
to get rid of such commits (a side-effect of the fact that the --apply
backend is not currently capable of keeping them).  While such users
could fire up an interactive rebase and just remove the lines
corresponding to empty commits, that might be difficult if the
third-party tool generates many of them.  Simplify this task for users
by marking such lines with a suffix of " # empty" in the todo list.

Suggested-by: Sami Boukortt <sami@boukortt.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-11 14:15:49 -07:00
Elijah Newren
1f6965f994 sequencer: honor GIT_REFLOG_ACTION
There is a lot of code to honor GIT_REFLOG_ACTION throughout git,
including some in sequencer.c; unfortunately, reflog_message() and its
callers ignored it.  Instruct reflog_message() to check the existing
environment variable, and use it when present as an override to
action_name().

Also restructure pick_commits() to only temporarily modify
GIT_REFLOG_ACTION for a short duration and then restore the old value,
so that when we do this setting within a loop we do not keep adding "
(pick)" substrings and end up with a reflog message of the form
    rebase (pick) (pick) (pick) (finish): returning to refs/heads/master

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-07 15:10:11 -07:00
Đoàn Trần Công Danh
cf0ad4d199 cherry-pick/revert: honour --no-gpg-sign in all case
{cherry-pick,revert} --edit hasn't honoured --no-gpg-sign yet.

Pass this option down to git-commit to honour it.

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-03 11:37:22 -07:00
Alban Gruin
68e7090f31 sequencer: don't abbreviate a command if it doesn't have a short form
When the sequencer is requested to abbreviate commands, it will replace
those that do not have a short form (eg. `noop') by a comment mark.
`noop' serves no purpose, except when fast-forwarding (ie. by running
`git rebase').  Removing it will break this command when
`rebase.abbreviateCommands' is set to true.

Teach todo_list_to_strbuf() to check if a command has an actual
short form, and to ignore it if not.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-30 12:47:08 -07:00
Alban Gruin
4d55d63bde sequencer: mark messages for translation
Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-28 18:11:25 -07:00
Junio C Hamano
4e4baee3f4 Merge branch 'bc/filter-process'
Provide more information (e.g. the object of the tree-ish in which
the blob being converted appears, in addition to its path, which
has already been given) to smudge/clean conversion filters.

* bc/filter-process:
  t0021: test filter metadata for additional cases
  builtin/reset: compute checkout metadata for reset
  builtin/rebase: compute checkout metadata for rebases
  builtin/clone: compute checkout metadata for clones
  builtin/checkout: compute checkout metadata for checkouts
  convert: provide additional metadata to filters
  convert: permit passing additional metadata to filter processes
  builtin/checkout: pass branch info down to checkout_worktree
2020-03-26 17:11:20 -07:00
Junio C Hamano
f8cb64e3d4 Merge branch 'bc/sha-256-part-1-of-4'
SHA-256 transition continues.

* bc/sha-256-part-1-of-4: (22 commits)
  fast-import: add options for rewriting submodules
  fast-import: add a generic function to iterate over marks
  fast-import: make find_marks work on any mark set
  fast-import: add helper function for inserting mark object entries
  fast-import: permit reading multiple marks files
  commit: use expected signature header for SHA-256
  worktree: allow repository version 1
  init-db: move writing repo version into a function
  builtin/init-db: add environment variable for new repo hash
  builtin/init-db: allow specifying hash algorithm on command line
  setup: allow check_repository_format to read repository format
  t/helper: make repository tests hash independent
  t/helper: initialize repository if necessary
  t/helper/test-dump-split-index: initialize git repository
  t6300: make hash algorithm independent
  t6300: abstract away SHA-1-specific constants
  t: use hash-specific lookup tables to define test constants
  repository: require a build flag to use SHA-256
  hex: add functions to parse hex object IDs in any algorithm
  hex: introduce parsing variants taking hash algorithms
  ...
2020-03-26 17:11:20 -07:00
Junio C Hamano
f085189f14 Merge branch 'pw/advise-rebase-skip'
The mechanism to prevent "git commit" from making an empty commit
or amending during an interrupted cherry-pick was broken during the
rewrite of "git rebase" in C, which has been corrected.

* pw/advise-rebase-skip:
  commit: give correct advice for empty commit during a rebase
  commit: encapsulate determine_whence() for sequencer
  commit: use enum value for multiple cherry-picks
  sequencer: write CHERRY_PICK_HEAD for reword and edit
  cherry-pick: check commit error messages
  cherry-pick: add test for `--skip` advice in `git commit`
  t3404: use test_cmp_rev
2020-03-25 13:57:43 -07:00
brian m. carlson
3f26785624 builtin/rebase: compute checkout metadata for rebases
Signed-off-by: brian m. carlson <bk2204@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-16 11:37:02 -07:00
Junio C Hamano
b4f0038525 Merge branch 'en/rebase-backend'
Band-aid fixes for two fallouts from switching the default "rebase"
backend.

* en/rebase-backend:
  git-rebase.txt: highlight backend differences with commit rewording
  sequencer: clear state upon dropping a become-empty commit
  i18n: unmark a message in rebase.c
2020-03-12 14:28:01 -07:00
Elijah Newren
9a1b7474d6 sequencer: clear state upon dropping a become-empty commit
In commit e98c4269c8 ("rebase (interactive-backend): fix handling of
commits that become empty", 2020-02-15), the merge backend was changed
to drop commits that did not start empty but became so after being
applied (because their changes were a subset of what was already
upstream).  This new code path did not need to go through the process of
creating a commit, since we were dropping the commit instead.
Unfortunately, this also means we bypassed the clearing of the
CHERRY_PICK_HEAD and MERGE_MSG files, which if there were no further
commits to cherry-pick would mean that the rebase would end but assume
there was still an operation in progress.  Ensure that we clear such
state files when we decide to drop the commit.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-11 12:11:05 -07:00
Junio C Hamano
8c22bd9ff9 Merge branch 'en/rebase-backend'
"git rebase" has learned to use the merge backend (i.e. the
machinery that drives "rebase -i") by default, while allowing
"--apply" option to use the "apply" backend (e.g. the moral
equivalent of "format-patch piped to am").  The rebase.backend
configuration variable can be set to customize.

* en/rebase-backend:
  rebase: rename the two primary rebase backends
  rebase: change the default backend from "am" to "merge"
  rebase: make the backend configurable via config setting
  rebase tests: repeat some tests using the merge backend instead of am
  rebase tests: mark tests specific to the am-backend with --am
  rebase: drop '-i' from the reflog for interactive-based rebases
  git-prompt: change the prompt for interactive-based rebases
  rebase: add an --am option
  rebase: move incompatibility checks between backend options a bit earlier
  git-rebase.txt: add more details about behavioral differences of backends
  rebase: allow more types of rebases to fast-forward
  t3432: make these tests work with either am or merge backends
  rebase: fix handling of restrict_revision
  rebase: make sure to pass along the quiet flag to the sequencer
  rebase, sequencer: remove the broken GIT_QUIET handling
  t3406: simplify an already simple test
  rebase (interactive-backend): fix handling of commits that become empty
  rebase (interactive-backend): make --keep-empty the default
  t3404: directly test the behavior of interest
  git-rebase.txt: update description of --allow-empty-message
2020-03-02 15:07:19 -08:00
brian m. carlson
42d4e1d112 commit: use expected signature header for SHA-256
The transition plan anticipates that we will allow signatures using
multiple algorithms in a single commit. In order to do so, we need to
use a different header per algorithm so that it will be obvious over
which data to compute the signature.

The transition plan specifies that we should use "gpgsig-sha256", so
wire up the commit code such that it can write and parse the current
algorithm, and it can remove the headers for any algorithm when creating
a new commit. Add tests to ensure that we write using the right header
and that git fsck doesn't reject these commits.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 09:33:30 -08:00
Elijah Newren
c2417d3af7 rebase: drop '-i' from the reflog for interactive-based rebases
A large variety of rebase types are supported by the interactive
machinery, not just the explicitly interactive ones.  These all share
the same code and write the same reflog messages, but the "-i" moniker
in those messages doesn't really have much meaning.  It also becomes
somewhat distracting once we switch the default from the am-backend to
the interactive one.  Just remove the "-i" from these messages.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16 15:40:42 -08:00
Elijah Newren
8a997ed132 rebase, sequencer: remove the broken GIT_QUIET handling
The GIT_QUIET environment variable was used to signal the non-am
backends that the rebase should perform quietly.  The preserve-merges
backend does not make use of the quiet flag anywhere (other than to
write out its state whenever it writes state), and this mechanism was
broken in the conversion from shell to C.  Since this environment
variable was specifically designed for scripts and the only backend that
would still use it is no longer a script, just gut this code.

A subsequent commit will fix --quiet for the interactive/merge backend
in a different way.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16 15:40:42 -08:00
Elijah Newren
e98c4269c8 rebase (interactive-backend): fix handling of commits that become empty
As established in the previous commit and commit b00bf1c9a8
(git-rebase: make --allow-empty-message the default, 2018-06-27), the
behavior for rebase with different backends in various edge or corner
cases is often more happenstance than design.  This commit addresses
another such corner case: commits which "become empty".

A careful reader may note that there are two types of commits which would
become empty due to a rebase:

  * [clean cherry-pick] Commits which are clean cherry-picks of upstream
    commits, as determined by `git log --cherry-mark ...`.  Re-applying
    these commits would result in an empty set of changes and a
    duplicative commit message; i.e. these are commits that have
    "already been applied" upstream.

  * [become empty] Commits which are not empty to start, are not clean
    cherry-picks of upstream commits, but which still become empty after
    being rebased.  This happens e.g. when a commit has changes which
    are a strict subset of the changes in an upstream commit, or when
    the changes of a commit can be found spread across or among several
    upstream commits.

Clearly, in both cases the changes in the commit in question are found
upstream already, but the commit message may not be in the latter case.

When cherry-mark can determine a commit is already upstream, then
because of how cherry-mark works this means the upstream commit message
was about the *exact* same set of changes.  Thus, the commit messages
can be assumed to be fully interchangeable (and are in fact likely to be
completely identical).  As such, the clean cherry-pick case represents a
case when there is no information to be gained by keeping the extra
commit around.  All rebase types have always dropped these commits, and
no one to my knowledge has ever requested that we do otherwise.

For many of the become empty cases (and likely even most), we will also
be able to drop the commit without loss of information -- but this isn't
quite always the case.  Since these commits represent cases that were
not clean cherry-picks, there is no upstream commit message explaining
the same set of changes.  Projects with good commit message hygiene will
likely have the explanation from our commit message contained within or
spread among the relevant upstream commits, but not all projects run
that way.  As such, the commit message of the commit being rebased may
have reasoning that suggests additional changes that should be made to
adapt to the new base, or it may have information that someone wants to
add as a note to another commit, or perhaps someone even wants to create
an empty commit with the commit message as-is.

Junio commented on the "become-empty" types of commits as follows[1]:

    WRT a change that ends up being empty (as opposed to a change that
    is empty from the beginning), I'd think that the current behaviour
    is desireable one.  "am" based rebase is solely to transplant an
    existing history and want to stop much less than "interactive" one
    whose purpose is to polish a series before making it publishable,
    and asking for confirmation ("this has become empty--do you want to
    drop it?") is more appropriate from the workflow point of view.

[1] https://lore.kernel.org/git/xmqqfu1fswdh.fsf@gitster-ct.c.googlers.com/

I would simply add that his arguments for "am"-based rebases actually
apply to all non-explicitly-interactive rebases.  Also, since we are
stating that different cases should have different defaults, it may be
worth providing a flag to allow users to select which behavior they want
for these commits.

Introduce a new command line flag for selecting the desired behavior:
    --empty={drop,keep,ask}
with the definitions:
    drop: drop commits which become empty
    keep: keep commits which become empty
    ask:  provide the user a chance to interact and pick what to do with
          commits which become empty on a case-by-case basis

In line with Junio's suggestion, if the --empty flag is not specified,
pick defaults as follows:
    explicitly interactive: ask
    otherwise: drop

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16 15:40:42 -08:00
Elijah Newren
d48e5e21da rebase (interactive-backend): make --keep-empty the default
Different rebase backends have different treatment for commits which
start empty (i.e. have no changes relative to their parent), and the
--keep-empty option was added at some point to allow adjusting behavior.
The handling of commits which start empty is actually quite similar to
commit b00bf1c9a8 (git-rebase: make --allow-empty-message the default,
2018-06-27), which pointed out that the behavior for various backends is
often more happenstance than design.  The specific change made in that
commit is actually quite relevant as well and much of the logic there
directly applies here.

It makes a lot of sense in 'git commit' to error out on the creation of
empty commits, unless an override flag is provided.  However, once
someone determines that there is a rare case that merits using the
manual override to create such a commit, it is somewhere between
annoying and harmful to have to take extra steps to keep such
intentional commits around.  Granted, empty commits are quite rare,
which is why handling of them doesn't get considered much and folks tend
to defer to existing (accidental) behavior and assume there was a reason
for it, leading them to just add flags (--keep-empty in this case) that
allow them to override the bad defaults.  Fix the interactive backend so
that --keep-empty is the default, much like we did with
--allow-empty-message.  The am backend should also be fixed to have
--keep-empty semantics for commits that start empty, but that is not
included in this patch other than a testcase documenting the failure.

Note that there was one test in t3421 which appears to have been written
expecting --keep-empty to not be the default as correct behavior.  This
test was introduced in commit 00b8be5a4d ("add tests for rebasing of
empty commits", 2013-06-06), which was part of a series focusing on
rebase topology and which had an interesting original cover letter at
https://lore.kernel.org/git/1347949878-12578-1-git-send-email-martinvonz@gmail.com/
which noted
    Your input especially appreciated on whether you agree with the
    intent of the test cases.
and then went into a long example about how one of the many tests added
had several questions about whether it was correct.  As such, I believe
most the tests in that series were about testing rebase topology with as
many different flags as possible and were not trying to state in general
how those flags should behave otherwise.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16 15:40:42 -08:00
Junio C Hamano
4dbeecba27 Merge branch 'ag/edit-todo-drop-check'
Allow the rebase.missingCommitsCheck configuration to kick in when
"rebase --edit-todo" and "rebase --continue" restarts the procedure.

* ag/edit-todo-drop-check:
  rebase-interactive: warn if commit is dropped with `rebase --edit-todo'
  sequencer: move check_todo_list_from_file() to rebase-interactive.c
2020-02-14 12:54:21 -08:00
Junio C Hamano
d8b8d59054 Merge branch 'ag/rebase-avoid-unneeded-checkout'
"git rebase -i" (and friends) used to unnecessarily check out the
tip of the branch to be rebased, which has been corrected.

* ag/rebase-avoid-unneeded-checkout:
  rebase -i: stop checking out the tip of the branch to rebase
2020-02-14 12:54:21 -08:00
Junio C Hamano
251187084d Merge branch 'js/rebase-i-with-colliding-hash'
"git rebase -i" identifies existing commits in its todo file with
their abbreviated object name, which could become ambigous as it
goes to create new commits, and has a mechanism to avoid ambiguity
in the main part of its execution.  A few other cases however were
not covered by the protection against ambiguity, which has been
corrected.

* js/rebase-i-with-colliding-hash:
  rebase -i: also avoid SHA-1 collisions with missingCommitsCheck
  rebase -i: re-fix short SHA-1 collision
  parse_insn_line(): improve error message when parsing failed
2020-02-14 12:54:20 -08:00
Jeff King
d20bc01a51 avoid computing zero offsets from NULL pointer
The Undefined Behavior Sanitizer in clang-11 seems to have learned a new
trick: it complains about computing offsets from a NULL pointer, even if
that offset is 0. This causes numerous test failures. For example, from
t1090:

  unpack-trees.c:1355:41: runtime error: applying zero offset to null pointer
  ...
  not ok 6 - in partial clone, sparse checkout only fetches needed blobs

The code in question looks like this:

  struct cache_entry **cache_end = cache + nr;
  ...
  while (cache != cache_end)

and we sometimes pass in a NULL and 0 for "cache" and "nr". This is
conceptually fine, as "cache_end" would be equal to "cache" in this
case, and we wouldn't enter the loop at all. But computing even a zero
offset violates the C standard. And given the fact that UBSan is
noticing this behavior, this might be a potential problem spot if the
compiler starts making unexpected assumptions based on undefined
behavior.

So let's just avoid it, which is pretty easy. In some cases we can just
switch to iterating with a numeric index (as we do in sequencer.c here).
In other cases (like the cache_end one) the use of an end pointer is
more natural; we can keep that by just explicitly checking for the
NULL/0 case when assigning the end pointer.

Note that there are two ways you can write this latter case, checking
for the pointer:

  cache_end = cache ? cache + nr : cache;

or the size:

  cache_end = nr ? cache + nr : cache;

For the case of a NULL/0 ptr/len combo, they are equivalent. But writing
it the second way (as this patch does) has the property that if somebody
were to incorrectly pass a NULL pointer with a non-zero length, we'd
continue to notice and segfault, rather than silently pretending the
length was zero.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 23:12:48 -08:00
Alban Gruin
5a5445d878 rebase-interactive: warn if commit is dropped with `rebase --edit-todo'
When set to "warn" or "error", `rebase.missingCommitsCheck' would make
`rebase -i' warn if the user removed commits from the todo list to
prevent mistakes.  Unfortunately, `rebase --edit-todo' and `rebase
--continue' don't take it into account.

This adds the ability for `rebase --edit-todo' and `rebase --continue'
to check if commits were dropped by the user.  As both edit_todo_list()
and complete_action() parse the todo list and check for dropped commits,
the code doing so in the latter is removed to reduce duplication.
`edit_todo_list_advice' is removed from sequencer.c as it is no longer
used there.

This changes when a backup of the todo list is made.  Until now, it was
saved only once, before the initial edit.  Now, it is also made if the
original todo list has no errors or no dropped commits.  Thus, the
backup should be error-free.  Without this, sequencer_continue()
(`rebase --continue') could only compare the current todo list against
the original, unedited list.  Before this change, this file was only
used by edit_todo_list() and `rebase -p' to create the backup before
the initial edit, and check_todo_list_from_file(), only used by
`rebase -p' to check for dropped commits after its own initial edit.

If the edited list has an error, a file, `dropped', is created to
report the issue.  Otherwise, it is deleted.  Usually, the edited list
is compared against the list before editing, but if this file exists,
it will be compared to the backup.  Also, if the file exists,
sequencer_continue() checks the list for dropped commits.  If the
check was performed every time, it would fail when resuming a rebase
after resolving a conflict, as the backup will contain commits that
were picked, but they will not be in the new list.  It's safe to
ignore this check if `dropped' does not exist, because that means that
no errors were found at the last edition, so any missing commits here
have already been picked.

Five tests are added to t3404.  The tests for
`rebase.missingCommitsCheck = warn' and `rebase.missingCommitsCheck =
error' have a similar structure.  First, we start a rebase with an
incorrect command on the first line.  Then, we edit the todo list,
removing the first and the last lines.  This demonstrates that
`--edit-todo' notices dropped commits, but not when the command is
incorrect.  Then, we restore the original todo list, and edit it to
remove the last line.  This demonstrates that if we add a commit after
the initial edit, then remove it, `--edit-todo' will notice that it
has been dropped.  Then, the actual rebase takes place.  In the third
test, it is also checked that `--continue' will refuse to resume the
rebase if commits were dropped.  The fourth test checks that no errors
are raised when resuming a rebase after resolving a conflict, the fifth
checks that no errors are raised when editing the todo list after
pausing the rebase.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 14:14:57 -08:00
Alban Gruin
1da5874c1b sequencer: move check_todo_list_from_file() to rebase-interactive.c
The message contained in `edit_todo_list_advice' (sequencer.c) is
printed after the initial edit of the todo list if it can't be parsed or
if commits were dropped.  This is done either in complete_action() for
`rebase -i', or in check_todo_list_from_file() for `rebase -p'.

Since we want to add this check when editing the list, we also want to
use this message from edit_todo_list() (rebase-interactive.c).  To this
end, check_todo_list_from_file() is moved to rebase-interactive.c, and
`edit_todo_list_advice' is copied there.  In the next commit,
complete_action() will stop using it, and `edit_todo_list_advice' will
be removed from sequencer.c.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 14:13:41 -08:00
Alban Gruin
767a9c417e rebase -i: stop checking out the tip of the branch to rebase
One of the first things done when using a sequencer-based
rebase (ie. `rebase -i', `rebase -r', or `rebase -m') is to make a todo
list.  This requires knowledge of the commit range to rebase.  To get
the oid of the last commit of the range, the tip of the branch to rebase
is checked out with prepare_branch_to_be_rebased(), then the oid of the
head is read.  After this, the tip of the branch is not even modified.
The `am' backend, on the other hand, does not check out the branch.

On big repositories, it's a performance penalty: with `rebase -i', the
user may have to wait before editing the todo list while git is
extracting the branch silently, and "quiet" rebases will be slower than
`am'.

Since we already have the oid of the tip of the branch in
`opts->orig_head', it's useless to switch to this commit.

This removes the call to prepare_branch_to_be_rebased() in
do_interactive_rebase(), and adds a `orig_head' parameter to
get_revision_ranges().  prepare_branch_to_be_rebased() is removed as it
is no longer used.

This introduces a visible change: as we do not switch on the tip of the
branch to rebase, no reflog entry is created at the beginning of the
rebase for it.

Unscientific performance measurements, performed on linux.git, are as
follow:

  Before this patch:

    $ time git rebase -m --onto v4.18 463fa44eec2fef50~ 463fa44eec2fef50

    real    0m8,940s
    user    0m6,830s
    sys     0m2,121s

  After this patch:

    $ time git rebase -m --onto v4.18 463fa44eec2fef50~ 463fa44eec2fef50

    real    0m1,834s
    user    0m0,916s
    sys     0m0,206s

Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-24 10:29:42 -08:00
Johannes Schindelin
b6992261de rebase -i: re-fix short SHA-1 collision
In 66ae9a57b8 (t3404: rebase -i: demonstrate short SHA-1 collision,
2013-08-23), we added a test case that demonstrated how it is possible
that a previously unambiguous short commit ID could become ambiguous
*during* a rebase.

In 75c6976655 (rebase -i: fix short SHA-1 collision, 2013-08-23), we
fixed that problem simply by writing out the todo list with expanded
commit IDs (except *right* before letting the user edit the todo list,
in which case we shorten them, but we expand them right after the file
was edited).

However, the bug resurfaced as a side effect of 393adf7a6f (sequencer:
directly call pick_commits() from complete_action(), 2019-11-24): as of
this commit, the sequencer no longer re-reads the todo list after
writing it out with expanded commit IDs.

The only redeeming factor is that the todo list is already parsed at
that stage, including all the commits corresponding to the commands,
therefore the sequencer can continue even if the internal todo list has
short commit IDs.

That does not prevent problems, though: the sequencer writes out the
`done` and `git-rebase-todo` files incrementally (i.e. overwriting the
todo list with a version that has _short_ commit IDs), and if a merge
conflict happens, or if an `edit` or a `break` command is encountered, a
subsequent `git rebase --continue` _will_ re-read the todo list, opening
an opportunity for the "short SHA-1 collision" bug again.

To avoid that, let's make sure that we do expand the commit IDs in the
todo list as soon as we have parsed it after letting the user edit it.

Additionally, we improve the 'short SHA-1 collide' test case in t3404 to
test specifically for the case where the rebase is resumed. We also
hard-code the expected colliding short SHA-1s, to document the
expectation (and to make it easier on future readers).

Note that we specifically test that the short commit ID is used in the
`git-rebase-todo.tmp` file: this file is created by the fake editor in
the test script and reflects the state that would have been presented to
the user to edit.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-23 12:48:11 -08:00
Johannes Schindelin
d859dcad94 parse_insn_line(): improve error message when parsing failed
In the case that a `get_oid()` call failed, we showed some rather bogus
part of the line instead of the precise string we sent to said function.
That makes it rather hard for users to understand what is going wrong,
so let's fix that.

While at it, return a negative value from `parse_insn_line()` in case of
an error, as per our convention. This function's only caller,
`todo_list_parse_insn_buffer()`, cares only whether that return value is
non-zero or not, i.e. does not need to be changed.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-23 12:48:05 -08:00
Junio C Hamano
4d924528d8 Revert "Merge branch 'ra/rebase-i-more-options'"
This reverts commit 5d9324e0f4, reversing
changes made to c58ae96fc4.

The topic turns out to be too buggy for real use.

cf. <f2fe7437-8a48-3315-4d3f-8d51fe4bb8f1@gmail.com>
2020-01-12 13:25:18 -08:00
Junio C Hamano
37c2619d91 Merge branch 'ag/sequencer-todo-updates'
Reduce unnecessary reading of state variables back from the disk
during sequencer operation.

* ag/sequencer-todo-updates:
  sequencer: directly call pick_commits() from complete_action()
  rebase: fill `squash_onto' in get_replay_opts()
  sequencer: move the code writing total_nr on the disk to a new function
  sequencer: update `done_nr' when skipping commands in a todo list
  sequencer: update `total_nr' when adding an item to a todo list
2019-12-16 13:08:31 -08:00
Junio C Hamano
7cc5f89088 Merge branch 'ag/sequencer-continue-leakfix'
Leakfix.

* ag/sequencer-continue-leakfix:
  sequencer: fix a memory leak in sequencer_continue()
2019-12-10 13:11:46 -08:00
Junio C Hamano
5d9324e0f4 Merge branch 'ra/rebase-i-more-options'
"git rebase -i" learned a few options that are known by "git
rebase" proper.

* ra/rebase-i-more-options:
  rebase -i: finishing touches to --reset-author-date
  rebase: add --reset-author-date
  rebase -i: support --ignore-date
  sequencer: rename amend_author to author_to_rename
  rebase -i: support --committer-date-is-author-date
  sequencer: allow callers of read_author_script() to ignore fields
  rebase -i: add --ignore-whitespace flag
2019-12-10 13:11:41 -08:00
Junio C Hamano
f233c9f455 Merge branch 'sg/assume-no-todo-update-in-cherry-pick'
While running "revert" or "cherry-pick --edit" for multiple
commits, a recent regression incorrectly detected "nothing to
commit, working tree clean", instead of replaying the commits,
which has been corrected.

* sg/assume-no-todo-update-in-cherry-pick:
  sequencer: don't re-read todo for revert and cherry-pick
2019-12-06 15:09:22 -08:00
Phillip Wood
430b75f720 commit: give correct advice for empty commit during a rebase
In dcb500dc16 (cherry-pick/revert: advise using --skip, 2019-07-02),
`git commit` learned to suggest to run `git cherry-pick --skip` when
trying to cherry-pick an empty patch.

However, it was overlooked that there are more conditions than just a
`git cherry-pick` when this advice is printed (which originally
suggested the neutral `git reset`): the same can happen during a rebase.

Let's suggest the correct command, even during a rebase.

While at it, we adjust more places in `builtin/commit.c` that
incorrectly assumed that the presence of a `CHERRY_PICK_HEAD` meant that
surely this must be a `cherry-pick` in progress.

Note: we take pains to handle the situation when a user runs a `git
cherry-pick` _during_ a rebase. This is quite valid (e.g. in an `exec`
line in an interactive rebase). On the other hand, it is not possible to
run a rebase during a cherry-pick, meaning: if both `rebase-merge/` and
`sequencer/` exist or CHERRY_PICK_HEAD and REBASE_HEAD point to the same
commit , we still want to advise to use `git cherry-pick --skip`.

Original-patch-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-06 09:32:02 -08:00
Phillip Wood
901ba7b1ef commit: encapsulate determine_whence() for sequencer
Working out which command wants to create a commit requires detailed
knowledge of the sequencer internals and that knowledge is going to
increase in subsequent commits. With that in mind lets encapsulate that
knowledge in sequencer.c rather than spreading it into builtin/commit.c.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-06 09:32:02 -08:00
Phillip Wood
21b11c6d1d sequencer: write CHERRY_PICK_HEAD for reword and edit
`git commit` relies on the presence of CHERRY_PICK_HEAD to show the
correct error message in the case of an empty pick.  This fixes a
regression introduced by the conversion from shell to C. In the shell
version everything was a cherry-pick as far as the sequencer code was
concerned so it always wrote CHERRY_PICK_HEAD. The conversion to C
forgot to update the code that creates CHERRY_PICK_HEAD. We do not want
to create CHERRY_PICK_HEAD for fixup and squash commands as that would
prevent `git commit --amend` from running.

Note that the error message shown by `git commit` for an empty pick
during a rebase is currently wrong as it talks about running `git
cherry-pick --skip` rather than `git rebase --skip`. This will be fixed
in a future commit which is why the tests are in t3403-rebase-skip.sh.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-06 09:32:01 -08:00
Junio C Hamano
c9208597a9 Merge branch 'pw/sequencer-compare-with-right-parent-to-check-empty-commits'
The sequencer machinery compared the HEAD and the state it is
attempting to commit to decide if the result would be a no-op
commit, even when amending a commit, which was incorrect, and
has been corrected.

* pw/sequencer-compare-with-right-parent-to-check-empty-commits:
  sequencer: fix empty commit check when amending
2019-12-05 12:52:46 -08:00
Junio C Hamano
995b1b1411 Merge branch 'dd/rebase-merge-reserves-onto-label'
The logic to avoid duplicate label names generated by "git rebase
--rebase-merges" forgot that the machinery itself uses "onto" as a
label name, which must be avoided by auto-generated labels, which
has been corrected.

* dd/rebase-merge-reserves-onto-label:
  sequencer: handle rebase-merges for "onto" message
2019-12-05 12:52:43 -08:00
Junio C Hamano
917d0d6234 Merge branch 'js/rebase-r-safer-label'
A label used in the todo list that are generated by "git rebase
--rebase-merges" is used as a part of a refname; the logic to come
up with the label has been tightened to avoid names that cannot be
used as such.

* js/rebase-r-safer-label:
  rebase -r: let `label` generate safer labels
  rebase-merges: move labels' whitespace mangling into `label_oid()`
2019-12-05 12:52:43 -08:00
Junio C Hamano
6511cb33c9 Merge branch 'dd/sequencer-utf8'
Handling of commit objects that use non UTF-8 encoding during
"rebase -i" has been improved.

* dd/sequencer-utf8:
  sequencer: reencode commit message for am/rebase --show-current-patch
  sequencer: reencode old merge-commit message
  sequencer: reencode squashing commit's message
  sequencer: reencode revert/cherry-pick's todo list
  sequencer: reencode to utf-8 before arrange rebase's todo list
  t3900: demonstrate git-rebase problem with multi encoding
  configure.ac: define ICONV_OMITS_BOM if necessary
  t0028: eliminate non-standard usage of printf
2019-12-01 09:04:36 -08:00
Junio C Hamano
d3096d2ba6 Merge branch 'en/doc-typofix'
Docfix.

* en/doc-typofix:
  Fix spelling errors in no-longer-updated-from-upstream modules
  multimail: fix a few simple spelling errors
  sha1dc: fix trivial comment spelling error
  Fix spelling errors in test commands
  Fix spelling errors in messages shown to users
  Fix spelling errors in names of tests
  Fix spelling errors in comments of testcases
  Fix spelling errors in code comments
  Fix spelling errors in documentation outside of Documentation/
  Documentation: fix a bunch of typos, both old and new
2019-12-01 09:04:35 -08:00
Alban Gruin
f6b9413baf sequencer: fix a memory leak in sequencer_continue()
When continuing an interactive rebase after a merge conflict was solved,
if the resolution could not be committed, sequencer_continue() would
return early without releasing its todo list, resulting in a memory
leak.  This plugs this leak by jumping to the end of the function, where
the todo list is deallocated.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-30 09:40:35 -08:00
Alban Gruin
393adf7a6f sequencer: directly call pick_commits() from complete_action()
Currently, complete_action(), used by builtin/rebase.c to start a new
rebase, calls sequencer_continue() to do it.  Before the former calls
pick_commits(), it

 - calls read_and_refresh_cache() -- this is unnecessary here as we've
   just called require_clean_work_tree() in complete_action()
 - calls read_populate_opts() -- this is unnecessary as we're starting a
   new rebase, so `opts' is fully populated
 - loads the todo list -- this is unnecessary as we've just populated
   the todo list in complete_action()
 - commits any staged changes -- this is unnecessary as we're starting a
   new rebase, so there are no staged changes
 - calls record_in_rewritten() -- this is unnecessary as we're starting
   a new rebase.

This changes complete_action() to directly call pick_commits() to avoid
these unnecessary steps.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-25 12:24:49 +09:00
Alban Gruin
3f34f2d8a4 sequencer: move the code writing total_nr on the disk to a new function
The total number of commands can be used to show the progression of the
rebasing in a shell.  It is written to the disk by read_populate_todo()
when the todo list is loaded from sequencer_continue() or
pick_commits(), but not by complete_action().

This moves the part writing total_nr to a new function so it can be
called from complete_action().

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-25 12:24:49 +09:00
Alban Gruin
34065541e3 sequencer: update `done_nr' when skipping commands in a todo list
In a todo list, `done_nr' is the number of commands that were executed
or skipped, but skip_unnecessary_picks() did not update it.

This variable is mostly used by command prompts (ie. git-prompt.sh and
the like).  As in the previous commit, this inconsistent behaviour is
not a problem yet, but it would start to matter at the end of this
series the same reason.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-25 12:24:48 +09:00