Commit Graph

309 Commits

Author SHA1 Message Date
Junio C Hamano
0e2a4764ed Merge branch 'jc/format-patch-force-in-body-from'
"git format-patch --from=<ident>" can be told to add an in-body
"From:" line even for commits that are authored by the given
<ident> with "--force-in-body-from"option.

* jc/format-patch-force-in-body-from:
  format-patch: learn format.forceInBodyFrom configuration variable
  format-patch: allow forcing the use of in-body From: header
  pretty: separate out the logic to decide the use of in-body from
2022-09-09 12:02:25 -07:00
Junio C Hamano
34bc1b1045 format-patch: allow forcing the use of in-body From: header
Users may be authoring and committing their commits under the same
e-mail address they use to send their patches from, in which case
they shouldn't need to use the in-body From: line in their outgoing
e-mails.  At the receiving end, "git am" will use the address on the
"From:" header of the incoming e-mail and all should be well.

Some mailing lists, however, mangle the From: address from what the
original sender had; in such a situation, the user may want to add
the in-body "From:" header even for their own patches.

"git format-patch --[no-]force-in-body-from" was invented for such
users.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-29 14:39:13 -07:00
Elijah Newren
257418c590 revision: allow --ancestry-path to take an argument
We have long allowed users to run e.g.
    git log --ancestry-path master..seen
which shows all commits which satisfy all three of these criteria:
  * are an ancestor of seen
  * are not an ancestor of master
  * have master as an ancestor

This commit allows another variant:
    git log --ancestry-path=$TOPIC master..seen
which shows all commits which satisfy all of these criteria:
  * are an ancestor of seen
  * are not an ancestor of master
  * have $TOPIC in their ancestry-path
that last bullet can be defined as commits meeting any of these
criteria:
    * are an ancestor of $TOPIC
    * have $TOPIC as an ancestor
    * are $TOPIC

This also allows multiple --ancestry-path arguments, which can be
used to find commits with any of the given topics in their ancestry
path.

Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 10:45:08 -07:00
Ævar Arnfjörð Bjarmason
f92dbdbc6a revisions API: don't leak memory on argv elements that need free()-ing
Add a "free_removed_argv_elements" member to "struct
setup_revision_opt", and use it to fix several memory leaks.

We have various memory leaks in APIs that take and munge "const
char **argv", e.g. parse_options(). Sometimes these APIs are given the
"argv" we get to the "main" function, in which case we don't leak
memory, but other times we're giving it the "v" member of a "struct
strvec" we created.

There's several potential ways to fix those sort of leaks, we could
add a "nodup" mode to "struct strvec", which would work for the cases
where we push constant strings to it. But that wouldn't work as soon
as we used strvec_pushf(), or otherwise needed to duplicate or create
a string for that "struct strvec".

Let's instead make it the responsibility of the revisions API. If it's
going to clobber elements of argv it can also free() them, which it
will now do if instructed to do so via "free_removed_argv_elements".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-03 11:12:36 -07:00
Junio C Hamano
2da81d1efb Merge branch 'ab/plug-leak-in-revisions'
Plug the memory leaks from the trickiest API of all, the revision
walker.

* ab/plug-leak-in-revisions: (27 commits)
  revisions API: add a TODO for diff_free(&revs->diffopt)
  revisions API: have release_revisions() release "topo_walk_info"
  revisions API: have release_revisions() release "date_mode"
  revisions API: call diff_free(&revs->pruning) in revisions_release()
  revisions API: release "reflog_info" in release revisions()
  revisions API: clear "boundary_commits" in release_revisions()
  revisions API: have release_revisions() release "prune_data"
  revisions API: have release_revisions() release "grep_filter"
  revisions API: have release_revisions() release "filter"
  revisions API: have release_revisions() release "cmdline"
  revisions API: have release_revisions() release "mailmap"
  revisions API: have release_revisions() release "commits"
  revisions API users: use release_revisions() for "prune_data" users
  revisions API users: use release_revisions() with UNLEAK()
  revisions API users: use release_revisions() in builtin/log.c
  revisions API users: use release_revisions() in http-push.c
  revisions API users: add "goto cleanup" for release_revisions()
  stash: always have the owner of "stash_info" free it
  revisions API users: use release_revisions() needing REV_INFO_INIT
  revision.[ch]: document and move code declared around "init"
  ...
2022-06-07 14:10:56 -07:00
Miklos Vajna
96697781e0 log: "--since-as-filter" option is a non-terminating "--since" variant
The "--since=<time>" option of "git log" limits the commits displayed by
the command by stopping the traversal once it sees a commit whose
timestamp is older than the given time and not digging further into its
parents.

This is OK in a history where a commit always has a newer timestamp than
any of its parents'.  Once you see a commit older than the given <time>,
all ancestor commits of it are even older than the time anyway.  It
poses, however, a problem when there is a commit with a wrong timestamp
that makes it appear older than its parents.  Stopping traversal at the
"incorrectly old" commit will hide its ancestors that are newer than
that wrong commit and are newer than the cut-off time given with the
--since option.  --max-age and --after being the synonyms to --since,
they share the same issue.

Add a new "--since-as-filter" option that is a variant of
"--since=<time>".  Instead of stopping the traversal to hide an old
enough commit and its all ancestors, exclude commits with an old
timestamp from the output but still keep digging the history.

Without other traversal stopping options, this will force the command in
"git log" family to dig down the history to the root.  It may be an
acceptable cost for a small project with short history and many commits
with screwy timestamps.

It is quite unlikely for us to add traversal stopper other than since,
so have this as a --since-as-filter option, rather than a separate
--as-filter, that would be probably more confusing.

Signed-off-by: Miklos Vajna <vmiklos@vmiklos.hu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-23 09:36:07 -07:00
Ævar Arnfjörð Bjarmason
f196c1e908 revisions API users: use release_revisions() needing REV_INFO_INIT
Use release_revisions() to various users of "struct rev_list" which
need to have their "struct rev_info" zero-initialized before we can
start using it.

For the bundle.c code see the early exit case added in
3bbbe467f2 (bundle verify: error out if called without an object
database, 2019-05-27).

For the relevant bisect.c code see 45b6370812 (bisect: libify
`check_good_are_ancestors_of_bad` and its dependents, 2020-02-17).

For the submodule.c code see the "goto" on "(!left || !right || !sub)"
added in 8e6df65015 (submodule: refactor show_submodule_summary with
helper function, 2016-08-31).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-13 23:56:08 -07:00
Ævar Arnfjörð Bjarmason
296a143845 revision.[ch]: document and move code declared around "init"
A subsequent commit will add "REV_INFO_INIT" macro adjacent to
repo_init_revisions(), unfortunately between the "struct rev_info"
itself and that function we've added various miscellaneous code
between the two over the years.

Let's move that code either lower in revision.h, giving it API docs
while we're at it, or in cases where it wasn't public API at all move
it into revision.c No lines of code are changed here, only moved
around. The only changes are the addition of new API comments.

The "tree_difference" variable could also be declared like this, which
I think would be a lot clearer, but let's leave that for now to keep
this a move-only change:

	static enum {
		REV_TREE_SAME,
		REV_TREE_NEW, /* Only new files */
		REV_TREE_OLD, /* Only files removed */
		REV_TREE_DIFFERENT, /* Mixed changes */
	} tree_difference = REV_TREE_SAME;

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-13 23:56:08 -07:00
Ævar Arnfjörð Bjarmason
1878b5edc0 revision.[ch]: provide and start using a release_revisions()
The users of the revision.[ch] API's "struct rev_info" are a major
source of memory leaks in the test suite under SANITIZE=leak, which in
turn adds a lot of noise when trying to mark up tests with
"TEST_PASSES_SANITIZE_LEAK=true".

The users of that API are largely one-shot, e.g. "git rev-list" or
"git log", or the "git checkout" and "git stash" being modified here

For these callers freeing the memory is arguably a waste of time, but
in many cases they've actually been trying to free the memory, and
just doing that in a buggy manner.

Let's provide a release_revisions() function for these users, and
start migrating them over per the plan outlined in [1]. Right now this
only handles the "pending" member of the struct, but more will be
added in subsequent commits.

Even though we only clear the "pending" member now, let's not leave a
trap in code like the pre-image of index_differs_from(), where we'd
start doing the wrong thing as soon as the release_revisions() learned
to clear its "diffopt". I.e. we need to call release_revisions() after
we've inspected any state in "struct rev_info".

This leaves in place e.g. clear_pathspec(&rev.prune_data) in
stash_working_tree() in builtin/stash.c, subsequent commits will teach
release_revisions() to free "prune_data" and other members that in
some cases are individually cleared by users of "struct rev_info" by
reaching into its members. Those subsequent commits will remove the
relevant calls to e.g. clear_pathspec().

We avoid amending code in index_differs_from() in diff-lib.c as well
as wt_status_collect_changes_index(), has_unstaged_changes() and
has_uncommitted_changes() in wt-status.c in a way that assumes that we
are already clearing the "diffopt" member. That will be handled in a
subsequent commit.

1. https://lore.kernel.org/git/87a6k8daeu.fsf@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-13 23:56:08 -07:00
Derrick Stolee
ffaa137f64 revision: put object filter into struct rev_info
Placing a 'struct list_objects_filter_options' within 'struct rev_info'
will assist making some bookkeeping around object filters in the future.

For now, let's use this new member to remove a static global instance of
the struct from builtin/rev-list.c.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-09 10:25:26 -08:00
Junio C Hamano
8813596531 Merge branch 'ah/log-no-graph'
"git log --graph --graph" used to leak a graph structure, and there
was no way to countermand "--graph" that appear earlier on the
command line.  A "--no-graph" option has been added and resource
leakage has been plugged.

* ah/log-no-graph:
  log: add a --no-graph option
  log: fix memory leak if --graph is passed multiple times
2022-02-23 16:58:03 -08:00
Junio C Hamano
708cbef33a Merge branch 'jz/rev-list-exclude-first-parent-only'
"git log" and friends learned an option --exclude-first-parent-only
to propagate UNINTERESTING bit down only along the first-parent
chain, just like --first-parent option shows commits that lack the
UNINTERESTING bit only along the first-parent chain.

* jz/rev-list-exclude-first-parent-only:
  git-rev-list: add --exclude-first-parent-only flag
2022-02-17 16:25:05 -08:00
Junio C Hamano
90b7153806 Merge branch 'en/remerge-diff'
"git log --remerge-diff" shows the difference from mechanical merge
result and the result that is actually recorded in a merge commit.

* en/remerge-diff:
  diff-merges: avoid history simplifications when diffing merges
  merge-ort: mark conflict/warning messages from inner merges as omittable
  show, log: include conflict/warning messages in --remerge-diff headers
  diff: add ability to insert additional headers for paths
  merge-ort: format messages slightly different for use in headers
  merge-ort: mark a few more conflict messages as omittable
  merge-ort: capture and print ll-merge warnings in our preferred fashion
  ll-merge: make callers responsible for showing warnings
  log: clean unneeded objects during `log --remerge-diff`
  show, log: provide a --remerge-diff capability
2022-02-16 15:14:29 -08:00
Alex Henrie
087c745833 log: add a --no-graph option
It's useful to be able to countermand a previous --graph option, for
example if `git log --graph` is run via an alias.

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-11 10:06:41 -08:00
Elijah Newren
7b90ab467a log: clean unneeded objects during log --remerge-diff
The --remerge-diff option will need to create new blobs and trees
representing the "automatic merge" state.  If one is traversing a
long project history, one can easily get hundreds of thousands of
loose objects generated during `log --remerge-diff`.  However, none of
those loose objects are needed after we have completed our diff
operation; they can be summarily deleted.

Add a new helper function to tmp_objdir to discard all the contained
objects, and call it after each merge is handled.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02 10:02:27 -08:00
Elijah Newren
db757e8b8d show, log: provide a --remerge-diff capability
When this option is specified, we remerge all (two parent) merge commits
and diff the actual merge commit to the automatically created version,
in order to show how users removed conflict markers, resolved the
different conflict versions, and potentially added new changes outside
of conflict regions in order to resolve semantic merge problems (or,
possibly, just to hide other random changes).

This capability works by creating a temporary object directory and
marking it as the primary object store.  This makes it so that any blobs
or trees created during the automatic merge are easily removable
afterwards by just deleting all objects from the temporary object
directory.

There are a few ways that this implementation is suboptimal:
  * `log --remerge-diff` becomes slow, because the temporary object
    directory can fill with many loose objects while running
  * the log output can be muddied with misplaced "warning: cannot merge
    binary files" messages, since ll-merge.c unconditionally writes those
    messages to stderr while running instead of allowing callers to
    manage them.
  * important conflict and warning messages are simply dropped; thus for
    conflicts like modify/delete or rename/rename or file/directory which
    are not representable with content conflict markers, there may be no
    way for a user of --remerge-diff to know that there had been a
    conflict which was resolved (and which possibly motivated other
    changes in the merge commit).
  * when fixing the previous issue, note that some unimportant conflict
    and warning messages might start being included.  We should instead
    make sure these remain dropped.
Subsequent commits will address these issues.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02 10:02:27 -08:00
Jerry Zhang
9d505b7b49 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>
2022-01-12 11:08:42 -08:00
René Scharfe
794c000267 log: let --invert-grep only invert --grep
The option --invert-grep is documented to filter out commits whose
messages match the --grep filters.  However, it also affects the
header matches (--author, --committer), which is not intended.

Move the handling of that option to grep.c, as only the code there can
distinguish between matches in the header from those in the message
body.  If --invert-grep is given then enable extended expressions (not
the regex type, we just need git grep's --not to work), negate the body
patterns and check if any of them match by piggy-backing on the
collect_hits mechanism of grep_source_1().

Collecting the matches in struct grep_opt is a bit iffy, but with
"last_shown" we have a precedent for writing state information to that
struct.

Reported-by: Dotan Cohen <dotancohen@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-17 14:13:08 -08:00
Junio C Hamano
921c795c25 Merge branch 'jt/add-submodule-odb-clean-up'
More code paths that use the hack to add submodule's object
database to the set of alternate object store have been cleaned up.

* jt/add-submodule-odb-clean-up:
  revision: remove "submodule" from opt struct
  repository: support unabsorbed in repo_submodule_init
  submodule: remove unnecessary unabsorbed fallback
2021-10-06 13:40:11 -07:00
Jonathan Tan
10a0d6ae64 revision: remove "submodule" from opt struct
Clean up a TODO in revision.h by removing the "submodule" field from
struct setup_revision_opt. This field is only used to specify the ref
store to use, so use rev_info->repo to determine the ref store instead.

The only users of this field are merge-ort.c and merge-recursive.c.
However, both these files specify the superproject as rev_info->repo and
the submodule as setup_revision_opt->submodule. In order to be able to
pass the submodule as rev_info->repo, all commits must be parsed with
the submodule explicitly specified; this patch does that as well. (An
incremental solution in which only some commits are parsed with explicit
submodule will not work, because if the same commit is parsed twice in
different repositories, there will be 2 heap-allocated object structs
corresponding to that commit, and any flag set by the revision walking
mechanism on one of them will not be reflected onto the other.)

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 14:09:30 -07:00
Patrick Steinhardt
29ef1f27fe revision: separate walk and unsorted flags
The `--no-walk` flag supports two modes: either it sorts the revisions
given as input input or it doesn't. This is reflected in a single
`no_walk` flag, which reflects one of the three states "walk", "don't
walk but without sorting" and "don't walk but with sorting".

Split up the flag into two separate bits, one indicating whether we
should walk or not and one indicating whether the input should be sorted
or not. This will allow us to more easily introduce a new flag
`--unsorted-input`, which only impacts the sorting bit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05 09:37:28 -07:00
Junio C Hamano
fe3fec53a6 Merge branch 'bc/rev-list-without-commit-line'
"git rev-list" learns to omit the "commit <object-name>" header
lines from the output with the `--no-commit-header` option.

* bc/rev-list-without-commit-line:
  rev-list: add option for --pretty=format without header
2021-07-22 13:05:56 -07:00
brian m. carlson
d1c5ae78ce 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>
2021-07-12 10:12:31 -07:00
Junio C Hamano
1ef488eaaa Merge branch 'jk/bitmap-tree-optim'
Avoid duplicated work while building reachability bitmaps.

* jk/bitmap-tree-optim:
  bitmaps: don't recurse into trees already in the bitmap
2021-07-08 13:15:00 -07:00
Jeff King
aa9ad6fee5 bitmaps: don't recurse into trees already in the bitmap
If an object is already mentioned in a reachability bitmap we are
building, then by definition so are all of the objects it can reach. We
have an optimization to stop traversing commits when we see they are
already in the bitmap, but we don't do the same for trees.

It's generally unavoidable to recurse into trees for commits not yet
covered by bitmaps (since most commits generally do have unique
top-level trees). But they usually have subtrees that are shared with
other commits (i.e., all of the subtrees the commit _didn't_ touch). And
some of those commits (and their trees) may be covered by the bitmap.

Usually this isn't _too_ big a deal, because we'll visit those subtrees
only once in total for the whole walk. But if you have a large number of
unbitmapped commits, and if your tree is big, then you may end up
opening a lot of sub-trees for no good reason.

We can use the same optimization we do for commits here: when we are
about to open a tree, see if it's in the bitmap (either the one we are
building, or the "seen" bitmap which covers the UNINTERESTING side of
the bitmap when doing a set-difference).

This works especially well because we'll visit all commits before
hitting any trees. So even in a history like:

  A -- B

if "A" has a bitmap on disk but "B" doesn't, we'll already have OR-ed in
the results from A before looking at B's tree (so we really will only
look at trees touched by B).

For most repositories, the timings produced by p5310 are unspectacular.
Here's linux.git:

  Test                         HEAD^             HEAD
  --------------------------------------------------------------------
  5310.4: simulated clone      6.00(5.90+0.10)   5.98(5.90+0.08) -0.3%
  5310.5: simulated fetch      2.98(5.45+0.18)   2.85(5.31+0.18) -4.4%
  5310.7: rev-list (commits)   0.32(0.29+0.03)   0.33(0.30+0.03) +3.1%
  5310.8: rev-list (objects)   1.48(1.44+0.03)   1.49(1.44+0.05) +0.7%

Any improvement there is within the noise (the +3.1% on test 7 has to be
noise, since we are not recursing into trees, and thus the new code
isn't even run). The results for git.git are likewise uninteresting.

But here are numbers from some other real-world repositories (that are
not public). This one's tree is comparable in size to linux.git, but has
~16k refs (and so less complete bitmap coverage):

  Test                         HEAD^               HEAD
  -------------------------------------------------------------------------
  5310.4: simulated clone      38.34(39.86+0.74)   33.95(35.53+0.76) -11.5%
  5310.5: simulated fetch      2.29(6.31+0.35)     2.20(5.97+0.41) -3.9%
  5310.7: rev-list (commits)   0.99(0.86+0.13)     0.96(0.85+0.11) -3.0%
  5310.8: rev-list (objects)   11.32(11.04+0.27)   6.59(6.37+0.21) -41.8%

And here's another with a very large tree (~340k entries), and a fairly
large number of refs (~10k):

  Test                         HEAD^               HEAD
  -------------------------------------------------------------------------
  5310.3: simulated clone      53.83(54.71+1.54)   39.77(40.76+1.50) -26.1%
  5310.4: simulated fetch      19.91(20.11+0.56)   19.79(19.98+0.67) -0.6%
  5310.6: rev-list (commits)   0.54(0.44+0.11)     0.51(0.43+0.07) -5.6%
  5310.7: rev-list (objects)   24.32(23.59+0.73)   9.85(9.49+0.36) -59.5%

This patch provides substantial improvements in these larger cases, and
have any drawbacks for smaller ones (the cost of the bitmap check is
quite small compared to an actual tree traversal).

Note that we have to add a version of revision.c's include_check
callback which handles non-commits. We could possibly consolidate this
into a single callback for all objects types, as there's only one user
of the feature which would need converted (pack-bitmap.c:should_include).
That would in theory let us avoid duplicating any logic. But when I
tried it, the code ended up much worse to read, with lots of repeated
"if it's a commit do this, otherwise do that". Having two separate
callbacks splits that naturally, and matches the existing split of
show_commit/show_object callbacks.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-15 11:13:11 +09:00
Junio C Hamano
8e444e66df Merge branch 'so/log-m-implies-p'
The "-m" option in "git log -m" that does not specify which format,
if any, of diff is desired did not have any visible effect; it now
implies some form of diff (by default "--patch") is produced.

* so/log-m-implies-p:
  diff-merges: let "-m" imply "-p"
  diff-merges: rename "combined_imply_patch" to "merges_imply_patch"
  stash list: stop passing "-m" to "git log"
  git-svn: stop passing "-m" to "git rev-list"
  diff-merges: move specific diff-index "-m" handling to diff-index
  t4013: test "git diff-index -m"
  t4013: test "git diff-tree -m"
  t4013: test "git log -m --stat"
  t4013: test "git log -m --raw"
  t4013: test that "-m" alone has no effect in "git log"
2021-06-14 13:33:27 +09:00
Sergey Organov
fd16a39944 diff-merges: rename "combined_imply_patch" to "merges_imply_patch"
This is refactoring change in preparation for the next commit that
will let -m imply -p.

The old name doesn't match the intention to let not only -c/-cc imply
-p, but also -m, that is not a "combined" format, so we rename the
flag accordingly.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-21 09:24:14 +09:00
Patrick Steinhardt
b2025da38b revision: mark commit parents as NOT_USER_GIVEN
The NOT_USER_GIVEN flag of an object marks whether a flag was explicitly
provided by the user or not. The most important use case for this is
when filtering objects: only objects that were not explicitly requested
will get filtered.

The flag is currently only set for blobs and trees, which has been fine
given that there are no filters for tags or commits currently. We're
about to extend filtering capabilities to add object type filter though,
which requires us to set up the NOT_USER_GIVEN flag correctly -- if it's
not set, the object wouldn't get filtered at all.

Mark unseen commit parents as NOT_USER_GIVEN when processing parents.
Like this, explicitly provided parents stay user-given and thus
unfiltered, while parents which get loaded as part of the graph walk
can be filtered.

This commit shouldn't have any user-visible impact yet as there is no
logic to filter commits yet.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-10 23:03:20 -07:00
Junio C Hamano
8a4394d1c1 Merge branch 'zh/format-patch-fractional-reroll-count'
"git format-patch -v<n>" learned to allow a reroll count that is
not an integer.

* zh/format-patch-fractional-reroll-count:
  format-patch: allow a non-integral version numbers
2021-04-02 14:43:14 -07:00
ZheNing Hu
db91988aa1 format-patch: allow a non-integral version numbers
The `-v<n>` option of `format-patch` can give nothing but an
integral iteration number to patches in a series.  Some people,
however, prefer to mark a new iteration with only a small fixup
with a non integral iteration number (e.g. an "oops, that was
wrong" fix-up patch for v4 iteration may be labeled as "v4.1").

Allow `format-patch` to take such a non-integral iteration
number.

`<n>` can be any string, such as '3.1' or '4rev2'. In the case
where it is a non-integral value, the "Range-diff" and "Interdiff"
headers will not include the previous version.

Signed-off-by: ZheNing Hu <adlternative@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-23 12:49:47 -07:00
Taylor Blau
c9fff00016 revision: learn '--no-kept-objects'
A future caller will want to be able to perform a reachability traversal
which terminates when visiting an object found in a kept pack. The
closest existing option is '--honor-pack-keep', but this isn't quite
what we want. Instead of halting the traversal midway through, a full
traversal is always performed, and the results are only trimmed
afterwords.

Besides needing to introduce a new flag (since culling results
post-facto can be different than halting the traversal as it's
happening), there is an additional wrinkle handling the distinction
in-core and on-disk kept packs. That is: what kinds of kept pack should
stop the traversal?

Introduce '--no-kept-objects[=<on-disk|in-core>]' to specify which kinds
of kept packs, if any, should stop a traversal. This can be useful for
callers that want to perform a reachability analysis, but want to leave
certain packs alone (for e.g., when doing a geometric repack that has
some "large" packs which are kept in-core that it wants to leave alone).

Note that this option is not guaranteed to produce exactly the set of
objects that aren't in kept packs, since it's possible the traversal
order may end up in a situation where a non-kept ancestor was "cut off"
by a kept object (at which point we would stop traversing). But, we
don't care about absolute correctness here, since this will eventually
be used as a purely additive guide in an upcoming new repack mode.

Explicitly avoid documenting this new flag, since it is only used
internally. In theory we could avoid even adding it rev-list, but being
able to spell this option out on the command-line makes some special
cases easier to test without promising to keep it behaving consistently
forever. Those tricky cases are exercised in t6114.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22 23:30:52 -08:00
Junio C Hamano
aac006aa99 Merge branch 'so/log-diff-merge'
"git log" learned a new "--diff-merges=<how>" option.

* so/log-diff-merge: (32 commits)
  t4013: add tests for --diff-merges=first-parent
  doc/git-show: include --diff-merges description
  doc/rev-list-options: document --first-parent changes merges format
  doc/diff-generate-patch: mention new --diff-merges option
  doc/git-log: describe new --diff-merges options
  diff-merges: add '--diff-merges=1' as synonym for 'first-parent'
  diff-merges: add old mnemonic counterparts to --diff-merges
  diff-merges: let new options enable diff without -p
  diff-merges: do not imply -p for new options
  diff-merges: implement new values for --diff-merges
  diff-merges: make -m/-c/--cc explicitly mutually exclusive
  diff-merges: refactor opt settings into separate functions
  diff-merges: get rid of now empty diff_merges_init_revs()
  diff-merges: group diff-merge flags next to each other inside 'rev_info'
  diff-merges: split 'ignore_merges' field
  diff-merges: fix -m to properly override -c/--cc
  t4013: add tests for -m failing to override -c/--cc
  t4013: support test_expect_failure through ':failure' magic
  diff-merges: revise revs->diff flag handling
  diff-merges: handle imply -p on -c/--cc logic for log.c
  ...
2021-02-05 16:40:44 -08:00
Sergey Organov
a6d19ecc6b diff-merges: let new options enable diff without -p
New options don't have any visible effect unless -p is either given or
implied, as unlike -c/-cc we don't imply -p with --diff-merges. To fix
this, this patch adds new functionality by letting new options enable
output of diffs for merge commits only.

Add 'merges_need_diff' field and set it whenever diff output for merges is
enabled by any of the new options.

Extend diff output logic accordingly, to output diffs for merges when
'merges_need_diff' is set even when no -p has been provided.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 13:47:32 -08:00
Sergey Organov
5733b20f41 diff-merges: do not imply -p for new options
Add 'combined_imply_patch' field and set it only for old --cc/-c
options, then imply -p if this flag is set instead of implying -p
whenever 'combined_merge' flag is set.

We don't want new --diff-merge options to imply -p, to make it
possible to enable output of diffs for merges independently from
non-merge commits. At the same time we want to preserve behavior of
old --c/-c/-m options and their interactions with --first-parent, to
stay backward-compatible.

This patch is first step in this direction: it separates old "--cc/-c
imply -p" logic from the rest of the options.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 13:47:32 -08:00
Sergey Organov
d9b1bc6d13 diff-merges: group diff-merge flags next to each other inside 'rev_info'
The relevant flags were somewhat scattered over definition of 'struct
rev_info'. Rearrange them to group them together.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 13:47:31 -08:00
Sergey Organov
1a2c4d8050 diff-merges: split 'ignore_merges' field
'ignore_merges' was 3-way field that served two distinct purposes that
we now assign to 2 new independent flags: 'separate_merges', and
'explicit_diff_merges'.

'separate_merges' tells that we need to output diff format containing
separate diff for every parent (as opposed to 'combine_merges').

'explicit_diff_merges' tells that at least one of diff-merges options
has been explicitly specified on the command line, so no defaults
should apply.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 13:47:31 -08:00
Sergey Organov
3291eea310 diff-merges: introduce revs->first_parent_merges flag
This new field allows us to separate format of diff for merges from
'first_parent_only' flag which primary purpose is limiting history
traversal.

This change further localizes diff format selection logic into the
diff-merges.c file.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 13:47:31 -08:00
Sergey Organov
a37eec6333 revision: move diff merges functions to its own diff-merges.c
Create separate diff-merges.c and diff-merges.h files, and move all
the code related to handling of diff merges there.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 13:47:30 -08:00
Sergey Organov
3d4fd94363 revision: provide implementation for diff merges tweaks
Use these implementations from show_setup_revisions_tweak() and
log_setup_revisions_tweak() in builtin/log.c.

This completes moving of management of diff merges parameters to a
single place, where we can finally observe them simultaneously.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 13:47:30 -08:00
Junio C Hamano
3baf58bfb4 format-patch: make output filename configurable
For the past 15 years, we've used the hardcoded 64 as the length
limit of the filename of the output from the "git format-patch"
command.  Since the value is shorter than the 80-column terminal, it
could grow without line wrapping a bit.  At the same time, since the
value is longer than half of the 80-column terminal, we could fit
two or more of them in "ls" output on such a terminal if we allowed
to lower it.

Introduce a new command line option --filename-max-length=<n> and a
new configuration variable format.filenameMaxLength to override the
hardcoded default.

While we are at it, remove a check that the name of output directory
does not exceed PATH_MAX---this check is pointless in that by the
time control reaches the function, the caller would already have
done an equivalent of "mkdir -p", so if the system does not like an
overly long directory name, the control wouldn't have reached here,
and otherwise, we know that the system allowed the output directory
to exist.  In the worst case, we will get an error when we try to
open the output file and handle the error correctly anyway.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-09 17:44:41 -08:00
Sergey Organov
572fc9aa54 revision: add separate field for "-m" of "diff-index -m"
Add separate 'match_missing' field for diff-index to use and set it when we
encounter "-m" option. This field won't then be cleared when another meaning of
"-m" is reverted (e.g., by "--no-diff-merges"), nor it will be affected by
future option(s) that might drive 'ignore_merges' field.

Use this new field from diff-lib:do_oneway_diff() instead of reusing
'ignore_merges' field.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-31 13:42:58 -07:00
Junio C Hamano
eca8c62a50 Merge branch 'jk/log-fp-implies-m'
"git log --first-parent -p" showed patches only for single-parent
commits on the first-parent chain; the "--first-parent" option has
been made to imply "-m".  Use "--no-diff-merges" to restore the
previous behaviour to omit patches for merge commits.

* jk/log-fp-implies-m:
  doc/git-log: clarify handling of merge commit diffs
  doc/git-log: move "-t" into diff-options list
  doc/git-log: drop "-r" diff option
  doc/git-log: move "Diff Formatting" from rev-list-options
  log: enable "-m" automatically with "--first-parent"
  revision: add "--no-diff-merges" option to counteract "-m"
  log: drop "--cc implies -m" logic
2020-08-17 17:02:49 -07:00
Junio C Hamano
70cdbbe3a7 Merge branch 'ds/commit-graph-bloom-updates' into master
Updates to the changed-paths bloom filter.

* ds/commit-graph-bloom-updates:
  commit-graph: check all leading directories in changed path Bloom filters
  revision: empty pathspecs should not use Bloom filters
  revision.c: fix whitespace
  commit-graph: check chunk sizes after writing
  commit-graph: simplify chunk writes into loop
  commit-graph: unify the signatures of all write_graph_chunk_*() functions
  commit-graph: persist existence of changed-paths
  bloom: fix logic in get_bloom_filter()
  commit-graph: change test to die on parse, not load
  commit-graph: place bloom_settings in context
2020-07-30 13:20:31 -07:00
Jeff King
6fae74b418 revision: add "--no-diff-merges" option to counteract "-m"
The "-m" option sets revs->ignore_merges to "0", but there's no way to
undo it. This probably isn't something anybody overly cares about, since
"1" is already the default, but it will serve as an escape hatch when we
flip the default for ignore_merges to "0" in more situations.

We'll also add a few extra niceties:

  - initialize the value to "-1" to indicate "not set", and then resolve
    it to the normal 0/1 bool in setup_revisions(). This lets any tweak
    functions, as well as setup_revisions() itself, avoid clobbering the
    user's preference (which until now they couldn't actually express).

  - since we now have --no-diff-merges, let's add the matching
    --diff-merges, which is just a synonym for "-m". Then we don't even
    need to document --no-diff-merges separately; it countermands the
    long form of "-m" in the usual way.

The new test shows that this behaves just the same as the current
behavior without "-m".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-29 13:43:57 -07:00
SZEDER Gábor
c525ce95b4 commit-graph: check all leading directories in changed path Bloom filters
The file 'dir/subdir/file' can only be modified if its leading
directories 'dir' and 'dir/subdir' are modified as well.

So when checking modified path Bloom filters looking for commits
modifying a path with multiple path components, then check not only
the full path in the Bloom filters, but all its leading directories as
well.  Take care to check these paths in "deepest first" order,
because it's the full path that is least likely to be modified, and
the Bloom filter queries can short circuit sooner.

This can significantly reduce the average false positive rate, by
about an order of magnitude or three(!), and can further speed up
pathspec-limited revision walks.  The table below compares the average
false positive rate and runtime of

  git rev-list HEAD -- "$path"

before and after this change for 5000+ randomly* selected paths from
each repository:

                    Average false           Average        Average
                    positive rate           runtime        runtime
                  before     after     before     after   difference
  ------------------------------------------------------------------
  git             3.220%   0.7853%     0.0558s   0.0387s   -30.6%
  linux           2.453%   0.0296%     0.1046s   0.0766s   -26.8%
  tensorflow      2.536%   0.6977%     0.0594s   0.0420s   -29.2%

*Path selection was done with the following pipeline:

	git ls-tree -r --name-only HEAD | sort -R | head -n 5000

The improvements in runtime are much smaller than the improvements in
average false positive rate, as we are clearly reaching diminishing
returns here.  However, all these timings depend on that accessing
tree objects is reasonably fast (warm caches).  If we had a partial
clone and the tree objects had to be fetched from a promisor remote,
e.g.:

  $ git clone --filter=tree:0 --bare file://.../webkit.git webkit.notrees.git
  $ git -C webkit.git -c core.modifiedPathBloomFilters=1 \
        commit-graph write --reachable
  $ cp webkit.git/objects/info/commit-graph webkit.notrees.git/objects/info/
  $ git -C webkit.notrees.git -c core.modifiedPathBloomFilters=1 \
        rev-list HEAD -- "$path"

then checking all leading path component can reduce the runtime from
over an hour to a few seconds (and this is with the clone and the
promisor on the same machine).

This adjusts the tracing values in t4216-log-bloom.sh, which provides a
concrete way to notice the improvement.

Helped-by: Taylor Blau <me@ttaylorr.com>
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-01 14:17:43 -07:00
René Scharfe
23c4319f0d revision: reallocate TOPO_WALK object flags
The bit fields in struct object have an unfortunate layout.  Here's what
pahole reports on x86_64 GNU/Linux:

struct object {
	unsigned int               parsed:1;             /*     0: 0  4 */
	unsigned int               type:3;               /*     0: 1  4 */

	/* XXX 28 bits hole, try to pack */

	/* Force alignment to the next boundary: */
	unsigned int               :0;

	unsigned int               flags:29;             /*     4: 0  4 */

	/* XXX 3 bits hole, try to pack */

	struct object_id           oid;                  /*     8    32 */

	/* size: 40, cachelines: 1, members: 4 */
	/* sum members: 32 */
	/* sum bitfield members: 33 bits, bit holes: 2, sum bit holes: 31 bits */
	/* last cacheline: 40 bytes */
};

Notice the 1+3+29=33 bits in bit fields and 28+3=31 bits in holes.

There are holes inside the flags bit field as well -- while some object
flags are used for more than one purpose, 22, 23 and 24 are still free.
Use  23 and 24 instead of 27 and 28 for TOPO_WALK_EXPLORED and
TOPO_WALK_INDEGREE.  This allows us to reduce FLAG_BITS by one so that
all bitfields combined fit into a single 32-bit slot:

struct object {
	unsigned int               parsed:1;             /*     0: 0  4 */
	unsigned int               type:3;               /*     0: 1  4 */
	unsigned int               flags:28;             /*     0: 4  4 */
	struct object_id           oid;                  /*     4    32 */

	/* size: 36, cachelines: 1, members: 4 */
	/* last cacheline: 36 bytes */
};

With this tight packing the size of struct object is reduced by 10%.
Other architectures probably benefit as well.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-24 09:09:44 -07:00
Junio C Hamano
9b6606f43d Merge branch 'gs/commit-graph-path-filter'
Introduce an extension to the commit-graph to make it efficient to
check for the paths that were modified at each commit using Bloom
filters.

* gs/commit-graph-path-filter:
  bloom: ignore renames when computing changed paths
  commit-graph: add GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS test flag
  t4216: add end to end tests for git log with Bloom filters
  revision.c: add trace2 stats around Bloom filter usage
  revision.c: use Bloom filters to speed up path based revision walks
  commit-graph: add --changed-paths option to write subcommand
  commit-graph: reuse existing Bloom filters during write
  commit-graph: write Bloom filters to commit graph file
  commit-graph: examine commits by generation number
  commit-graph: examine changed-path objects in pack order
  commit-graph: compute Bloom filters for changed paths
  diff: halt tree-diff early after max_changes
  bloom.c: core Bloom filter implementation for changed paths.
  bloom.c: introduce core Bloom filter constructs
  bloom.c: add the murmur3 hash implementation
  commit-graph: define and use MAX_NUM_CHUNKS
2020-05-01 13:39:53 -07:00
Junio C Hamano
9af3a7cb4d Merge branch 'ds/revision-show-pulls'
"git log" learned "--show-pulls" that helps pathspec limited
history views; a merge commit that takes the whole change from a
side branch, which is normally omitted from the output, is shown
in addition to the commits that introduce real changes.

* ds/revision-show-pulls:
  revision: --show-pulls adds helpful merges
2020-04-22 13:42:57 -07:00
Derrick Stolee
8d049e182e 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 09:58:55 -07:00
Emma Brooks
19d097e3d7 format-patch: teach --no-encode-email-headers
When commit subjects or authors have non-ASCII characters, git
format-patch Q-encodes them so they can be safely sent over email.
However, if the patch transfer method is something other than email (web
review tools, sneakernet), this only serves to make the patch metadata
harder to read without first applying it (unless you can decode RFC 2047
in your head). git am as well as some email software supports
non-Q-encoded mail as described in RFC 6531.

Add --[no-]encode-email-headers and format.encodeEmailHeaders to let the
user control this behavior.

Signed-off-by: Emma Brooks <me@pluvano.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-07 22:37:18 -07:00