Elijah Newren [Fri, 14 Jan 2022 15:59:43 +0000 (15:59 +0000)]
Accelerate clear_skip_worktree_from_present_files() by caching
Trying to clear the skip-worktree bit from files that are present does
present some computational overhead, for sparse-checkouts. (We do not
do the bit clearing in non-sparse-checkouts.) Optimize it as follows:
Rather than lstat()'ing every SKIP_WORKTREE path, take advantage of the
fact that entire directories will often be missing, especially for cone
mode and even more so ever since commit 55dfcf9591 ("sparse-checkout:
clear tracked sparse dirs", 2021-09-08). If we have already determined
that the parent directory of a file (or other previous ancestor) does
not exist, then the file cannot exist either so we do not need to
lstat() it separately.
Timings for p2000 included below, reformatted to fit in normal commit
message line lengths, which compare three things:
* Timings before this series
* Timings of the unoptimized version of
clear_skip_worktree_from_present_files() from a few commits ago
* Timings after the optimization in this commit
(NOTE: t/perf/ appears to have timing resolution only down to 0.01 s,
which presents significant measurement error when timings only differ by
0.01s. I don't trust any such timings below, and yet all the optimized
results differ by at most 0.01s.)
So, with the optimization, the extra work appears to be essentially 0
for sparse-checkouts that are also using sparse-indexes (even before my
optimization), and the extra work appears to be just marginally more
than 0 for sparse-checkouts that are using full indexes.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Fri, 14 Jan 2022 15:59:42 +0000 (15:59 +0000)]
Update documentation related to sparsity and the skip-worktree bit
Make several small updates, to address a few documentation issues
I spotted:
* sparse-checkout focused on "patterns" even though the inputs (and
outputs in the case of `list`) are directories in cone-mode
* The description section of the sparse-checkout documentation
was a bit sparse (no pun intended), and focused more on internal
mechanics rather than end user usage. This made sense in the
early days when the command was even more experimental, but let's
adjust a bit to try to make it more approachable to end users who
may want to consider using it. Keep the scary backward
compatibility warning, though; we're still hard at work trying to
fix up commands to behave reasonably in sparse checkouts.
* both read-tree and update-index tried to describe how to use the
skip-worktree bit, but both predated the sparse-checkout command.
The sparse-checkout command is a far easier mechanism to use and
for users trying to reduce the size of their working tree, we
should recommend users to look at it instead.
* The update-index documentation pointed out that assume-unchanged
and skip-worktree sounded similar but had different purposes.
However, it made no attempt to explain the differences, only to
point out that they were different. Explain the differences.
* The update-index documentation focused much more on (internal?)
implementation details than on end-user usage. Try to explain
its purpose better for users of update-index, rather than
fellow developers trying to work with the SKIP_WORKTREE bit.
* Clarify that when core.sparseCheckout=true, we treat a file's
presence in the working tree as being an override to the
SKIP_WORKTREE bit (i.e. in sparse checkouts when the file is
present we ignore the SKIP_WORKTREE bit).
Note that this commit, like many touching documentation, is best viewed
with the `--color-words` option to diff/log.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Fri, 14 Jan 2022 15:59:41 +0000 (15:59 +0000)]
repo_read_index: clear SKIP_WORKTREE bit from files present in worktree
The fix is short (~30 lines), but the description is not. Sorry.
There is a set of problems caused by files in what I'll refer to as the
"present-despite-SKIP_WORKTREE" state. This commit aims to not just fix
these problems, but remove the entire class as a possibility -- for
those using sparse checkouts. But first, we need to understand the
problems this class presents. A quick outline:
* Problems
* User facing issues
* Problem space complexity
* Maintenance and code correctness challenges
* SKIP_WORKTREE expectations in Git
* Suggested solution
* Pros/Cons of suggested solution
* Notes on testcase modifications
=== User facing issues ===
There are various ways for users to get files to be present in the
working copy despite having the SKIP_WORKTREE bit set for that file in
the index. This may come from:
* various git commands not really supporting the SKIP_WORKTREE bit[1,2]
* users grabbing files from elsewhere and writing them to the worktree
(perhaps even cached in their editor)
* users attempting to "abort" a sparse-checkout operation with a
not-so-early Ctrl+C (updating $GIT_DIR/info/sparse-checkout and the
working tree is not atomic)[3].
Once users have present-despite-SKIP_WORKTREE files, any modifications
users make to these files will be ignored, possibly to users' confusion.
Further:
* these files will degrade performance for the sparse-index case due
to requiring the index to be expanded (see commit 55dfcf9591
("sparse-checkout: clear tracked sparse dirs", 2021-09-08) for why
we try to delete entire directories outside the sparse cone).
* these files will not be updated by by standard commands
(switch/checkout/pull/merge/rebase will leave them alone unless
conflicts happen -- and even then, the conflicted file may be
written somewhere else to avoid overwriting the SKIP_WORKTREE file
that is present and in the way)
* there is nothing in Git that users can use to discover such
files (status, diff, grep, etc. all ignore it)
* there is no reasonable mechanism to "recover" from such a condition
(neither `git sparse-checkout reapply` nor `git reset --hard` will
correct it).
So, not only are users modifications ignored, but the files get
progressively more stale over time. At some point in the future, they
may change their sparseness specification or disable sparse-checkouts.
At that time, all present-despite-SKIP_WORKTREE files will show up as
having lots of modifications because they represent a version from a
different branch or commit. These might include user-made local changes
from days before, but the only way to tell is to have users look through
them all closely.
If these users come to others for help, there will be no logs that
explain the issue; it's just a mysterious list of changes. Users might
adamantly claim (correctly, as it turns out) that they didn't modify
these files, while others presume they did.
SKIP_WORKTREE has been part of Git for over a decade. Duy did lots of
work on it initially, and several others have since come along and put
lots of work into it. Stolee spent most of 2021 on the sparse-index,
with lots of bugfixes along the way including to non-sparse-index cases
as we are still trying to get sparse checkouts to behave reasonably.
Basically every codepath throughout the treat needs to be aware of an
additional type of file: tracked-but-not-present. The extra type
results in lots of extra testcases and lots of extra code everywhere.
But, the sad thing is that we actually have more than one extra type.
We have tracked, tracked-but-not-present (SKIP_WORKTREE), and
tracked-but-promised-to-not-be-present-but-is-present-anyway
(present-despite-SKIP_WORKTREE). Two types is a monumental amount of
effort to support, and adding a third feels a bit like insanity[4].
[4] Some examples of which can be seen at
https://lore.kernel.org/git/CABPp-BGJ_Nvi5TmgriD9Bh6eNXE2EDq2f8e8QKXAeYG3BxZafA@mail.gmail.com/
=== Maintenance and code correctness challenges ===
Matheus' patches to grep stalled for nearly a year, in part because of
complications of how to handle sparse-checkouts appropriately in all
cases[5][6] (with trying to sanely figure out how to sanely handle
present-despite-SKIP_WORKTREE files being one of the complications).
His rm/add follow-ups also took months because of those kinds of
issues[7]. The corner cases with things like submodules and
SKIP_WORKTREE with the addition of present-despite-SKIP_WORKTREE start
becoming really complex[8].
We've had to add ugly logic to merge-ort to attempt to handle
present-despite-SKIP_WORKTREE files[9], and basically just been forced
to give up in merge-recursive knowing full well that we'll sometimes
silently discard user modifications. Despite stash essentially being a
merge, it needed extra code (beyond what was in merge-ort and
merge-recursive) to manually tweak SKIP_WORKTREE bits in order to avoid
a few different bugs that'd result in an early abort with a partial
stash application[10].
[5] See https://lore.kernel.org/git/5f3f7ac77039d41d1692ceae4b0c5df3bb45b74a.1612901326.git.matheus.bernardino@usp.br/#t
and the dates on the thread; also Matheus and I had several
conversations off-list trying to resolve the issues over that time
[6] ...it finally kind of got unstuck after
https://lore.kernel.org/git/CABPp-BGJ_Nvi5TmgriD9Bh6eNXE2EDq2f8e8QKXAeYG3BxZafA@mail.gmail.com/
[7] See for example
https://lore.kernel.org/git/CABPp-BHwNoVnooqDFPAsZxBT9aR5Dwk5D9sDRCvYSb8akxAJgA@mail.gmail.com/#t
and quotes like "The core functionality of sparse-checkout has always
been only partially implemented", a statement I still believe is true
today.
[8] https://lore.kernel.org/git/pull.809.git.git.1592356884310.gitgitgadget@gmail.com/
[9] See commit 66b209b86a ("merge-ort: implement CE_SKIP_WORKTREE
handling with conflicted entries", 2021-03-20)
[10] See commit ba359fd507 ("stash: fix stash application in
sparse-checkouts", 2020-12-01)
=== SKIP_WORKTREE expectations in Git ===
A couple quotes:
* From [11] (before the "sparse-checkout" command existed):
If it needs too many special cases, hacks, and conditionals, then it
is not worth the complexity---if it is easier to write a correct code
by allowing Git to populate working tree files, it is perfectly fine
to do so.
In a sense, the sparse checkout "feature" itself is a hack by itself,
and that is why I think this part should be "best effort" as well.
* From the git-sparse-checkout manual (still present today):
THIS COMMAND IS EXPERIMENTAL. ITS BEHAVIOR, AND THE BEHAVIOR OF OTHER
COMMANDS IN THE PRESENCE OF SPARSE-CHECKOUTS, WILL LIKELY CHANGE IN
THE FUTURE.
SKIP_WORKTREE was written to allow sparse-checkouts, in particular, as
the name of the option implies, to allow the file to NOT be in the
worktree but consider it to be unchanged rather than deleted.
The suggests a simple solution: present-despite-SKIP_WORKTREE files
should not exist, for those using sparse-checkouts.
Enforce this at index loading time by checking if core.sparseCheckout is
true; if so, check files in the index with the SKIP_WORKTREE bit set to
verify that they are absent from the working tree. If they are present,
unset the bit (in memory, though any commands that write to the index
will record the update).
Users can, of course, can get the SKIP_WORKTREE bit back such as by
running `git sparse-checkout reapply` (if they have ensured the file is
unmodified and doesn't match the specified sparsity patterns).
=== Pros/Cons of suggested solution ===
Pros:
* Solves the user visible problems reported above, which I've been
complaining about for nearly a year but couldn't find a solution to.
* Helps prevent slow performance degradation with a sparse-index.
* Much easier behavior in sparse-checkouts for users to reason about
* Very simple, ~30 lines of code.
* Significantly simplifies some ugly testcases, and obviates the need
to test an entire class of potential issues.
* Reduces code complexity, reasoning, and maintenance. Avoids
disagreements about weird corner cases[12].
* It has been reported that some users might be (ab)using
SKIP_WORKTREE as a let-me-modify-but-keep-the-file-in-the-worktree
mechanism[13, and a few other similar references]. These users know
of multiple caveats and shortcomings in doing so; perhaps not
surprising given the "SKIP_WORKTREE expecations" section above.
However, these users use `git update-index --skip-worktree`, and not
`git sparse-checkout` or core.sparseCheckout=true. As such, these
users would be unaffected by this change and can continue abusing
the system as before.
* When core.sparseCheckout is enabled, this adds a performance cost to
reading the index. I'll defer discussion of this cost to a subsequent
patch, since I have some optimizations to add.
=== Notes on testcase modifications ===
The good:
* t1011: Compare to two cases above it ('read-tree will not throw away
dirty changes, non-sparse'); since the file is present, it should
match the non-sparse case now
* t1092: sparse-index & sparse-checkout now match full-worktree
behavior in more cases! Yaay for consistency!
* t6428, t7012: look at how much simpler the tests become! Merge and
stash can just fail early telling the user there's a file in the
way, instead of not noticing until it's about to write a file and
then have to implement sudden crash avoidance. Hurray for sanity!
* t7817: sparse behavior better matches full tree behavior. Hurray
for sanity!
The confusing:
* t3705: These changes were ONLY needed on Windows, but they don't
hurt other platforms. Let's discuss each individually:
* core.sparseCheckout should be false by default. Nothing in this
testcase toggles that until many, many tests later. However,
early tests (#5 in particular) were testing `update-index
--skip-worktree` behavior in a non-sparse-checkout, but the
Windows tests in CI were behaving as if core.sparseCheckout=true
had been specified somewhere. I do not have access to a Windows
machine. But I just manually did what should have been a no-op
and turned the config off. And it fixed the test.
* I have no idea why the leftover .gitattributes file from this
test was causing failures for test #18 on Windows, but only with
these changes of mine. Test #18 was checking for empty stderr,
and specifically wanted to know that some error completely
unrelated to file endings did not appear. The leftover
.gitattributes file thus caused some spurious stderr unrelated to
the thing being checked. Since other tests did not intend to
test normalization, just proactively remove the .gitattributes
file. I'm certain this is cleaner and better, I'm just unsure
why/how this didn't trigger problems before.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Fri, 14 Jan 2022 15:59:40 +0000 (15:59 +0000)]
unpack-trees: fix accidental loss of user changes
For sparse-checkouts, we don't want unpack-trees to error out on files
that are missing from the worktree, so there has traditionally been
logic to make it skip the verify_uptodate() check for these.
Unfortunately, it was skipping the verify_uptodate() check for files
that were expected to *become* SKIP_WORKTREE. For files that were not
already SKIP_WORKTREE, that can cause us to later delete the file in
apply_sparse_checkout(). Only skip the check for files that were
already SKIP_WORKTREE as well to avoid lightly discarding important
changes users may have made to files.
Note 1: unpack-trees.c is already a bit complex, and the logic around
CE_SKIP_WORKTREE and CE_NEW_SKIP_WORKTREE in that file are no exception.
I also tried just replacing CE_NEW_SKIP_WORKTREE with CE_SKIP_WORKTREE
in the verify_uptodate() check instead of checking for both flags, and
found that it also fixed this bug and passed all the tests. I also
attempted to devise a few testcases that might trip either variant of my
fix and was unable to find any problems. It may be that just checking
CE_SKIP_WORKTREE is a better fix, but I'm not sure. I thought it
was a bit safer to strictly reduce the number of cases where we skip the
up-to-date check rather than just toggling which kind of cases skip it,
and thus went with the current variant of the fix.
Note 2: I also wondered if verify_absent() might have a similar bug, but
despite my attempts to try to devise a testcase that would trigger such
a thing, I couldn't find any problematic testcases. Thus, this patch
makes no attempt to apply similar changes to verify_absent() and
verify_absent_if_directory().
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Fri, 14 Jan 2022 15:59:39 +0000 (15:59 +0000)]
t1011: add testcase demonstrating accidental loss of user modifications
If a user has a file with local modifications that is not marked as
SKIP_WORKTREE, but the sparsity patterns are such that it should be
marked that way, and the user then invokes a command like
* git checkout -q HEAD^
or
* git read-tree -mu HEAD^
Then the file will be deleted along with all the users' modifications.
Add a testcase demonstrating this problem.
Note: This bug only triggers if something other than 'HEAD' is given;
if the commands above had specified 'HEAD', then the users' file would
be left alone.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Thu, 13 Jan 2022 21:50:44 +0000 (13:50 -0800)]
Merge branch 'vd/sparse-clean-etc' into en/present-despite-skipped
* vd/sparse-clean-etc:
update-index: reduce scope of index expansion in do_reupdate
update-index: integrate with sparse index
update-index: add tests for sparse-checkout compatibility
checkout-index: integrate with sparse index
checkout-index: add --ignore-skip-worktree-bits option
checkout-index: expand sparse checkout compatibility tests
clean: integrate with sparse index
reset: reorder wildcard pathspec conditions
reset: fix validation in sparse index test
Victoria Dye [Tue, 11 Jan 2022 18:05:06 +0000 (18:05 +0000)]
update-index: reduce scope of index expansion in do_reupdate
Replace unconditional index expansion in 'do_reupdate()' with one scoped to
only where a full index is needed. A full index is only required in
'do_reupdate()' when a sparse directory in the index differs from HEAD; in
that case, the index is expanded and the operation restarted.
Because the index should only be expanded if a sparse directory is modified,
add a test ensuring the index is not expanded when differences only exist
within the sparse cone.
Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye [Tue, 11 Jan 2022 18:05:05 +0000 (18:05 +0000)]
update-index: integrate with sparse index
Enable use of the sparse index with `update-index`. Most variations of
`update-index` work without explicitly expanding the index or making any
other updates in or outside of `update-index.c`.
The one usage requiring additional changes is `--cacheinfo`; if a file
inside a sparse directory was specified, the index would not be expanded
until after the cache tree is invalidated, leading to a mismatch between the
index and cache tree. This scenario is handled by rearranging
`add_index_entry_with_check`, allowing `index_name_stage_pos` to expand the
index *before* attempting to invalidate the relevant cache tree path,
avoiding cache tree/index corruption.
Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye [Tue, 11 Jan 2022 18:05:04 +0000 (18:05 +0000)]
update-index: add tests for sparse-checkout compatibility
Introduce tests for a variety of `git update-index` use cases, including
performance scenarios. Tests are intended to exercise `update-index` with
options that change the commands interaction with the index (e.g.,
`--again`) and with files/directories inside and outside a sparse checkout
cone.
Of note is that these tests clearly establish the behavior of `git
update-index --add` with untracked, outside-of-cone files. Unlike `git add`,
which fails with an error when provided with such files, `update-index`
succeeds in adding them to the index. Additionally, the `skip-worktree` flag
is *not* automatically added to the new entry. Although this is pre-existing
behavior, there are a couple of reasons to avoid changing it in favor of
consistency with e.g. `git add`:
* `update-index` is low-level command for modifying the index; while it can
perform operations similar to those of `add`, it traditionally has fewer
"guardrails" preventing a user from doing something they may not want to
do (in this case, adding an outside-of-cone, non-`skip-worktree` file to
the index)
* `update-index` typically only exits with an error code if it is incapable
of performing an operation (e.g., if an internal function call fails);
adding a new file outside the sparse checkout definition is still a valid
operation, albeit an inadvisable one
* `update-index` does not implicitly set flags (e.g., `skip-worktree`) when
creating new index entries with `--add`; if flags need to be updated,
options like `--[no-]skip-worktree` allow a user to intentionally set them
All this to say that, while there are valid reasons to consider changing the
treatment of outside-of-cone files in `update-index`, there are also
sufficient reasons for leaving it as-is.
Co-authored-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye [Tue, 11 Jan 2022 18:05:03 +0000 (18:05 +0000)]
checkout-index: integrate with sparse index
Add repository settings to allow usage of the sparse index.
When using the `--all` option, sparse directories are ignored by default due
to the `skip-worktree` flag, so there is no need to expand the index. If
`--ignore-skip-worktree-bits` is specified, the index is expanded in order
to check out all files.
When checking out individual files, existing behavior in a full index is to
exit with an error if a directory is specified (as the directory name will
not match an index entry). However, it is possible in a sparse index to
match a directory name to a sparse directory index entry, but checking out
that sparse directory still results in an error on checkout. To reduce some
potential confusion for users, `checkout_file(...)` explicitly exits with an
informative error if provided with a sparse directory name. The test
corresponding to this scenario verifies the error message, which now differs
between sparse index and non-sparse index checkouts.
Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update `checkout-index` to no longer refresh files that have the
`skip-worktree` bit set, exiting with an error if `skip-worktree` filenames
are directly provided to `checkout-index`. The newly-added
`--ignore-skip-worktree-bits` option provides a mechanism to replicate the
old behavior, checking out *all* files specified (even those with
`skip-worktree` enabled).
The ability to toggle whether files should be checked-out based on
`skip-worktree` already exists in `git checkout` and `git restore` (both of
which have an `--ignore-skip-worktree-bits` option). The change to, by
default, ignore `skip-worktree` files is especially helpful for
sparse-checkout; it prevents inadvertent creation of files outside the
sparse definition on disk and eliminates the need to expand a sparse index
when using the `--all` option.
Internal usage of `checkout-index` in `git stash` and `git filter-branch` do
not make explicit use of files with `skip-worktree` enabled, so
`--ignore-skip-worktree-bits` is not added to them.
Helped-by: Elijah Newren <newren@gmail.com> Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add tests to cover `checkout-index`, with a focus on cases interesting in a
sparse checkout (e.g., files specified outside sparse checkout definition).
New tests are intended to serve as a baseline for existing and/or expected
behavior and performance when integrating `checkout-index` with the sparse
index. Note that the test 'checkout-index --all' is marked as
'test_expect_failure', indicating that `update-index --all` will be modified
in a subsequent patch to behave as the test expects.
Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye [Tue, 11 Jan 2022 18:05:00 +0000 (18:05 +0000)]
clean: integrate with sparse index
Remove full index requirement for `git clean` and test to ensure the index
is not expanded in `git clean`. Add to existing test for `git clean` to
verify cleanup of untracked files in sparse directories is consistent
between sparse index and non-sparse index checkouts.
Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye [Tue, 11 Jan 2022 18:04:59 +0000 (18:04 +0000)]
reset: reorder wildcard pathspec conditions
Rearrange conditions in method determining whether index expansion is
necessary when a pathspec is specified for `git reset`, placing less
expensive condition first. Additionally, add details & examples to related
code comments to help with readability.
Helped-by: Elijah Newren <newren@gmail.com> Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye [Tue, 11 Jan 2022 18:04:58 +0000 (18:04 +0000)]
reset: fix validation in sparse index test
Update t1092 test 'reset with pathspecs outside sparse definition' to verify
index contents. The use of `rev-parse` verifies the contents of HEAD, not
the index, providing no real validation of the reset results. Conversely,
`ls-files` reports the contents of the index (OIDs, flags, filenames), which
are then compared across checkouts to ensure compatible index states.
Fixes 741a2c9ffa (reset: expand test coverage for sparse checkouts,
2021-09-27).
Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Wed, 12 Jan 2022 20:11:42 +0000 (12:11 -0800)]
packfile: fix off-by-one error in decoding logic
shift count being exactly at 7-bit smaller than the long is OK; on
32-bit architecture, shift count starts at 4 and goes through 11, 18
and 25, at which point the guard triggers one iteration too early.
Reported-by: Marc Strapetz <marc.strapetz@syntevo.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fabian Stelzer [Wed, 12 Jan 2022 12:07:57 +0000 (13:07 +0100)]
t/gpg: simplify test for unknown key
To test for a key that is completely unknown to the keyring we need one
to sign the commit with. This was done by generating a new key and not
add it into the keyring. To avoid the key generation overhead and
problems where GPG did hang in CI during it, switch GNUPGHOME to the
empty $GNUPGHOME_NOT_USED instead, therefore making all used keys unknown
for this single `verify-commit` call.
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Fabian Stelzer <fs@gigacodes.de> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Bagas Sanjaya [Tue, 11 Jan 2022 12:36:27 +0000 (19:36 +0700)]
branch: missing space fix at line 313
The message introduced by commit 593a2a5d06 (branch: protect branches
checked out in all worktrees, 2021-12-01) is missing a space in the
first line, add it.
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Mon, 10 Jan 2022 21:19:06 +0000 (16:19 -0500)]
fmt-merge-msg: prevent use-after-free with signed tags
When merging a signed tag, fmt_merge_msg_sigs() is responsible for
populating the body of the merge message with the names of the signed
tags, their signatures, and the validity of those signatures.
In 02769437e1 (ssh signing: use sigc struct to pass payload,
2021-12-09), check_signature() was taught to pass the object payload via
the sigc struct instead of passing the payload buffer separately.
In effect, 02769437e1 causes buf, and sigc.payload to point at the same
region in memory. This causes a problem for fmt_tag_signature(), which
wants to read from this location, since it is freed beforehand by
signature_check_clear() (which frees it via sigc's `payload` member).
That makes the subsequent use in fmt_tag_signature() a use-after-free.
As a result, merge messages did not contain the body of any signed tags.
Luckily, they tend not to contain garbage, either, since the result of
strstr()-ing the object buffer in fmt_tag_signature() is guarded:
const char *tag_body = strstr(buf, "\n\n");
if (tag_body) {
tag_body += 2;
strbuf_add(tagbuf, tag_body, buf + len - tag_body);
}
Unfortunately, the tests in t6200 did not catch this at the time because
they do not search for the body of signed tags in fmt-merge-msg's
output.
Resolve this by waiting to call signature_check_clear() until after its
contents can be safely discarded. Harden ourselves against any future
regressions in this area by making sure we can find signed tag messages
in the output of fmt-merge-msg, too.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Mon, 10 Jan 2022 19:52:56 +0000 (11:52 -0800)]
Merge branch 'ja/i18n-similar-messages'
Similar message templates have been consolidated so that
translators need to work on fewer number of messages.
* ja/i18n-similar-messages:
i18n: turn even more messages into "cannot be used together" ones
i18n: ref-filter: factorize "%(foo) atom used without %(bar) atom"
i18n: factorize "--foo outside a repository"
i18n: refactor "unrecognized %(foo) argument" strings
i18n: factorize "no directory given for --foo"
i18n: factorize "--foo requires --bar" and the like
i18n: tag.c factorize i18n strings
i18n: standardize "cannot open" and "cannot read"
i18n: turn "options are incompatible" into "cannot be used together"
i18n: refactor "%s, %s and %s are mutually exclusive"
i18n: refactor "foo and bar are mutually exclusive"
Junio C Hamano [Mon, 10 Jan 2022 19:52:54 +0000 (11:52 -0800)]
Merge branch 'js/branch-track-inherit'
"git -c branch.autosetupmerge=inherit branch new old" makes "new"
to have the same upstream as the "old" branch, instead of marking
"old" itself as its upstream.
* js/branch-track-inherit:
config: require lowercase for branch.*.autosetupmerge
branch: add flags and config to inherit tracking
branch: accept multiple upstream branches for tracking
Junio C Hamano [Mon, 10 Jan 2022 19:52:53 +0000 (11:52 -0800)]
Merge branch 'ab/usage-die-message'
Code clean-up to hide vreportf() from public API.
* ab/usage-die-message:
config API: use get_error_routine(), not vreportf()
usage.c + gc: add and use a die_message_errno()
gc: return from cmd_gc(), don't call exit()
usage.c API users: use die_message() for error() + exit 128
usage.c API users: use die_message() for "fatal :" + exit 128
usage.c: add a die_message() routine
Junio C Hamano [Mon, 10 Jan 2022 19:52:53 +0000 (11:52 -0800)]
Merge branch 'jz/apply-3-corner-cases'
"git apply --3way" bypasses the attempt to do a three-way
application in more cases to address the regression caused by the
recent change to use direct application as a fallback.
* jz/apply-3-corner-cases:
git-apply: skip threeway in add / rename cases
Junio C Hamano [Mon, 10 Jan 2022 19:52:52 +0000 (11:52 -0800)]
Merge branch 'ab/reflog-prep'
Code refactoring in the reflog part of refs API.
* ab/reflog-prep:
reflog + refs-backend: move "verbose" out of the backend
refs files-backend: assume cb->newlog if !EXPIRE_REFLOGS_DRY_RUN
reflog: reduce scope of "struct rev_info"
reflog expire: don't use lookup_commit_reference_gently()
reflog expire: refactor & use "tip_commit" only for UE_NORMAL
reflog expire: use "switch" over enum values
reflog: change one->many worktree->refnames to use a string_list
reflog expire: narrow scope of "cb" in cmd_reflog_expire()
reflog delete: narrow scope of "cmd" passed to count_reflog_ent()
Junio C Hamano [Mon, 10 Jan 2022 19:52:52 +0000 (11:52 -0800)]
Merge branch 'ab/do-not-limit-stash-help-to-push'
"git stash" by default triggers its "push" action, but its
implementation also made "git stash -h" to show short help only for
"git stash push", which has been corrected.
* ab/do-not-limit-stash-help-to-push:
stash: don't show "git stash push" usage on bad "git stash" usage
Junio C Hamano [Mon, 10 Jan 2022 19:52:51 +0000 (11:52 -0800)]
Merge branch 'hn/refs-debug-update'
Debugging support for refs API.
* hn/refs-debug-update:
refs: centralize initialization of the base ref_store.
refs: print error message in debug output
refs: pass gitdir to packed_ref_store_create
Junio C Hamano [Mon, 10 Jan 2022 19:52:50 +0000 (11:52 -0800)]
Merge branch 'hn/ref-api-tests-update'
Test updates.
* hn/ref-api-tests-update:
t7004: use "test-tool ref-store" for reflog inspection
t7004: create separate tags for different tests
t5550: require REFFILES
t5540: require REFFILES
Use of certain "git rev-list" options with "git fast-export"
created nonsense results (the worst two of which being "--reverse"
and "--invert-grep --grep=<foo>"). The use of "--first-parent" is
made to behave a bit more sensible than before.
* ws/fast-export-with-revision-options:
fast-export: fix surprising behavior with --first-parent
Certain sparse-checkout patterns that are valid in non-cone mode
led to segfault in cone mode, which has been corrected.
* ds/sparse-checkout-malformed-pattern-fix:
sparse-checkout: refuse to add to bad patterns
sparse-checkout: fix OOM error with mixed patterns
sparse-checkout: fix segfault on malformed patterns
Martin Ågren [Mon, 10 Jan 2022 18:41:34 +0000 (19:41 +0100)]
cache.h: drop duplicate `ensure_full_index()` declaration
There are two identical declarations of `ensure_full_index()` in
cache.h.
Commit 3964fc2aae ("sparse-index: add guard to ensure full index",
2021-03-30) provided an empty implementation of `ensure_full_index()`,
declaring it in a new file sparse-index.h. When commit 4300f8442a
("sparse-index: implement ensure_full_index()", 2021-03-30) fleshed out
the implementation, it added an identical declaration to cache.h.
Then 118a2e8bde ("cache: move ensure_full_index() to cache.h",
2021-04-01) favored having the declaration in cache.h. Because of the
double declaration, at that point we could have just dropped the one in
sparse-index.h, but instead it got moved to cache.h.
As a result, cache.h contains the exact same function declaration twice.
Drop the one under "/* Name hashing */", in favor of the one under
"/* Initialize and use the cache information */".
Signed-off-by: Martin Ågren <martin.agren@gmail.com> Acked-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Christoph Reiter reported on the Git for Windows issue tracker[1], that
mingw_strftime() imports strftime() from ucrtbase.dll with the wrong
calling convention. It should be __cdecl instead of WINAPI, which we
always use in DECLARE_PROC_ADDR().
The MSYS2 project encountered cmake sefaults on x86 Windows caused by
the same issue in the cmake source. [2] There are no known git crashes
that where caused by this, yet, but we should try to prevent them.
We import two other non-WINAPI functions via DECLARE_PROC_ADDR(), too.
Reported-By: Christoph Reiter <reiter.christoph@gmail.com> Signed-off-by: Matthias Aßhauer <mha1993@live.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch: fix deadlock when cleaning up lockfiles in async signals
When fetching packfiles, we write a bunch of lockfiles for the packfiles
we're writing into the repository. In order to not leave behind any
cruft in case we exit or receive a signal, we register both an exit
handler as well as signal handlers for common signals like SIGINT. These
handlers will then unlink the locks and free the data structure tracking
them. We have observed a deadlock in this logic though:
(gdb) bt
#0 __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:95
#1 0x00007f4932bea2cd in _int_free (av=0x7f4932f2eb20 <main_arena>, p=0x3e3e4200, have_lock=0) at malloc.c:3969
#2 0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
#3 0x0000000000662ab1 in string_list_clear ()
#4 0x000000000044f5bc in unlock_pack_on_signal ()
#5 <signal handler called>
#6 _int_free (av=0x7f4932f2eb20 <main_arena>, p=<optimized out>, have_lock=0) at malloc.c:4024
#7 0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
#8 0x000000000065afd5 in strbuf_release ()
#9 0x000000000066ddb9 in delete_tempfile ()
#10 0x0000000000610d0b in files_transaction_cleanup.isra ()
#11 0x0000000000611718 in files_transaction_abort ()
#12 0x000000000060d2ef in ref_transaction_abort ()
#13 0x000000000060d441 in ref_transaction_prepare ()
#14 0x000000000060e0b5 in ref_transaction_commit ()
#15 0x00000000004511c2 in fetch_and_consume_refs ()
#16 0x000000000045279a in cmd_fetch ()
#17 0x0000000000407c48 in handle_builtin ()
#18 0x0000000000408df2 in cmd_main ()
#19 0x00000000004078b5 in main ()
The process was killed with a signal, which caused the signal handler to
kick in and try free the data structures after we have unlinked the
locks. It then deadlocks while calling free(3P).
The root cause of this is that it is not allowed to call certain
functions in async-signal handlers, as specified by signal-safety(7).
Next to most I/O functions, this list of disallowed functions also
includes memory-handling functions like malloc(3P) and free(3P) because
they may not be reentrant. As a result, if we execute such functions in
the signal handler, then they may operate on inconistent state and fail
in unexpected ways.
Fix this bug by not calling non-async-signal-safe functions when running
in the signal handler. We're about to re-raise the signal anyway and
will thus exit, so it's not much of a problem to keep the string list of
lockfiles untouched. Note that it's fine though to call unlink(2), so
we'll still clean up the lockfiles correctly.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Wed, 5 Jan 2022 22:01:30 +0000 (14:01 -0800)]
Merge branch 'rs/log-invert-grep-with-headers'
"git log --invert-grep --author=<name>" used to exclude commits
written by the given author, but now "--invert-grep" only affects
the matches made by the "--grep=<pattern>" option.
* rs/log-invert-grep-with-headers:
log: let --invert-grep only invert --grep
Junio C Hamano [Wed, 5 Jan 2022 22:01:29 +0000 (14:01 -0800)]
Merge branch 'jc/merge-detached-head-name'
The default merge message prepared by "git merge" records the name
of the current branch; the name can be overridden with a new option
to allow users to pretend a merge is made on a different branch.
* jc/merge-detached-head-name:
merge: allow to pretend a merge is made into a different branch
Junio C Hamano [Wed, 5 Jan 2022 22:01:29 +0000 (14:01 -0800)]
Merge branch 'km/help-prompt-fix'
Among some code paths that ask an yes/no question, only one place
gave a prompt that looked different from the others, which has been
updated to match what the others create.
* km/help-prompt-fix:
help: make auto-correction prompt more consistent
"git upload-pack" (the other side of "git fetch") used a 8kB buffer
but most of its payload came on 64kB "packets". The buffer size
has been enlarged so that such a packet fits.
Junio C Hamano [Wed, 5 Jan 2022 22:01:29 +0000 (14:01 -0800)]
Merge branch 'pw/diff-color-moved-fix'
Correctness and performance update to "diff --color-moved" feature.
* pw/diff-color-moved-fix:
diff --color-moved: intern strings
diff: use designated initializers for emitted_diff_symbol
diff --color-moved-ws=allow-indentation-change: improve hash lookups
diff --color-moved: stop clearing potential moved blocks
diff --color-moved: shrink potential moved blocks as we go
diff --color-moved: unify moved block growth functions
diff --color-moved: call comparison function directly
diff --color-moved-ws=allow-indentation-change: simplify and optimize
diff: simplify allow-indentation-change delta calculation
diff --color-moved: avoid false short line matches and bad zebra coloring
diff --color-moved=zebra: fix alternate coloring
diff --color-moved: rewind when discarding pmb
diff --color-moved: factor out function
diff --color-moved: clear all flags on blocks that are too short
diff --color-moved: add perf tests
Junio C Hamano [Wed, 5 Jan 2022 22:01:28 +0000 (14:01 -0800)]
Merge branch 'xw/am-empty'
"git am" learns "--empty=(stop|drop|keep)" option to tweak what is
done to a piece of e-mail without a patch in it.
* xw/am-empty:
am: support --allow-empty to record specific empty patches
am: support --empty=<option> to handle empty patches
doc: git-format-patch: describe the option --always
Junio C Hamano [Wed, 5 Jan 2022 22:01:28 +0000 (14:01 -0800)]
Merge branch 'en/keep-cwd'
Many git commands that deal with working tree files try to remove a
directory that becomes empty (i.e. "git switch" from a branch that
has the directory to another branch that does not would attempt
remove all files in the directory and the directory itself). This
drops users into an unfamiliar situation if the command was run in
a subdirectory that becomes subject to removal due to the command.
The commands have been taught to keep an empty directory if it is
the directory they were started in to avoid surprising users.
* en/keep-cwd:
t2501: simplify the tests since we can now assume desired behavior
dir: new flag to remove_dir_recurse() to spare the original_cwd
dir: avoid incidentally removing the original_cwd in remove_path()
stash: do not attempt to remove startup_info->original_cwd
rebase: do not attempt to remove startup_info->original_cwd
clean: do not attempt to remove startup_info->original_cwd
symlinks: do not include startup_info->original_cwd in dir removal
unpack-trees: add special cwd handling
unpack-trees: refuse to remove startup_info->original_cwd
setup: introduce startup_info->original_cwd
t2501: add various tests for removing the current working directory
Junio C Hamano [Wed, 5 Jan 2022 22:01:27 +0000 (14:01 -0800)]
Merge branch 'jh/p4-rcs-expansion-in-bytestring'
The RCS keyword substitution in "git p4" used to be done assuming
that the contents are UTF-8 text, which can trigger decoding
errors. We now treat the contents as a bytestring for robustness
and correctness.
* jh/p4-rcs-expansion-in-bytestring:
git-p4: resolve RCS keywords in bytes not utf-8
git-p4: open temporary patch file for write only
git-p4: add raw option to read_pipelines
git-p4: pre-compile RCS keyword regexes
git-p4: use with statements to close files after use in patchRCSKeywords
Lénaïc Huard [Wed, 5 Jan 2022 08:18:35 +0000 (09:18 +0100)]
grep: align default colors with GNU grep ones
git-grep shares a lot of options with the standard grep tool.
Like GNU grep, it has coloring options to highlight the matching text.
And like it, it has options to customize the various colored parts.
This patch updates the default git-grep colors to make them match the
GNU grep default ones [1].
It was possible to get the same result by setting the various `color.grep.<slot>`
options, but this patch makes `git grep --color` share the same color scheme as
`grep --color` by default without any user configuration.
Elijah Newren [Tue, 4 Jan 2022 23:04:58 +0000 (23:04 +0000)]
stash: do not return before restoring untracked files
In commit bee8691f19 ("stash: restore untracked files AFTER restoring
tracked files", 2021-09-10), we correctly identified that we should
restore changes to tracked files before attempting to restore untracked
files, and accordingly moved the code for restoring untracked files a
few lines down in do_apply_stash(). Unfortunately, the intervening
lines had some early return statements meaning that we suddenly stopped
restoring untracked files in some cases.
Even before the previous commit, there was another possible issue with
the current code -- a post-stash-apply 'git status' that was intended
to be run after restoring the stash was skipped when we hit a conflict
(or other error condition), which seems slightly inconsistent.
Fix both issues by saving the return status, and letting other
functionality run before returning.
Reported-by: AJ Henderson Test-case-by: Randall S. Becker <randall.becker@nexbridge.ca> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
James Limbouris [Wed, 8 Dec 2021 02:11:58 +0000 (02:11 +0000)]
subtree: fix argument handling in check_parents
315a84f9aa0 (subtree: use commits before rejoins for splits, 2018-09-28)
changed the signature of check_parents from 'check_parents [REV...]'
to 'check_parents PARENTS_EXPR INDENT'. In other words the variable list
of parent revisions became a list embedded in a string. However it
neglected to unpack the list again before sending it to cache_miss,
leading to incorrect calls whenever more than one parent was present.
This is the case whenever a merge commit is processed, with the end
result being a loss of performance from unecessary rechecks.
The indent parameter was subsequently removed in e9525a8a029 (subtree:
have $indent actually affect indentation, 2021-04-27), but the argument
handling bug remained.
For consistency, take multiple arguments in check_parents,
and pass all of them to cache_miss separately.
Signed-off-by: James Limbouris <james@digitalmatter.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 4 Jan 2022 00:24:15 +0000 (16:24 -0800)]
Merge branch 'en/sparse-checkout-set'
The "init" and "set" subcommands in "git sparse-checkout" have been
unified for a better user experience and performance.
* en/sparse-checkout-set:
sparse-checkout: remove stray trailing space
clone: avoid using deprecated `sparse-checkout init`
Documentation: clarify/correct a few sparsity related statements
git-sparse-checkout.txt: update to document init/set/reapply changes
sparse-checkout: enable reapply to take --[no-]{cone,sparse-index}
sparse-checkout: enable `set` to initialize sparse-checkout mode
sparse-checkout: split out code for tweaking settings config
sparse-checkout: disallow --no-stdin as an argument to set
sparse-checkout: add sanity-checks on initial sparsity state
sparse-checkout: break apart functions for sparse_checkout_(set|add)
sparse-checkout: pass use_stdin as a parameter instead of as a global
Junio C Hamano [Tue, 4 Jan 2022 00:24:15 +0000 (16:24 -0800)]
Merge branch 'es/test-chain-lint'
Broken &&-chains in the test scripts have been corrected.
* es/test-chain-lint:
t6000-t9999: detect and signal failure within loop
t5000-t5999: detect and signal failure within loop
t4000-t4999: detect and signal failure within loop
t0000-t3999: detect and signal failure within loop
tests: simplify by dropping unnecessary `for` loops
tests: apply modern idiom for exiting loop upon failure
tests: apply modern idiom for signaling test failure
tests: fix broken &&-chains in `{...}` groups
tests: fix broken &&-chains in `$(...)` command substitutions
tests: fix broken &&-chains in compound statements
tests: use test_write_lines() to generate line-oriented output
tests: simplify construction of large blocks of text
t9107: use shell parameter expansion to avoid breaking &&-chain
t6300: make `%(raw:size) --shell` test more robust
t5516: drop unnecessary subshell and command invocation
t4202: clarify intent by creating expected content less cleverly
t1020: avoid aborting entire test script when one test fails
t1010: fix unnoticed failure on Windows
t/lib-pager: use sane_unset() to avoid breaking &&-chain
Derrick Stolee [Thu, 16 Dec 2021 16:13:42 +0000 (16:13 +0000)]
sparse-checkout: refuse to add to bad patterns
When in cone mode sparse-checkout, it is unclear how 'git
sparse-checkout add <dir1> ...' should behave if the existing
sparse-checkout file does not match the cone mode patterns. Change the
behavior to fail with an error message about the existing patterns.
Also, all cone mode patterns start with a '/' character, so add that
restriction. This is necessary for our example test 'cone mode: warn on
bad pattern', but also requires modifying the example sparse-checkout
file we use to test the warnings related to recognizing cone mode
patterns.
This error checking would cause a failure further down the test script
because of a test that adds non-cone mode patterns without cleaning them
up. Perform that cleanup as part of the test now.
Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Thu, 16 Dec 2021 16:13:41 +0000 (16:13 +0000)]
sparse-checkout: fix OOM error with mixed patterns
Add a test to t1091-sparse-checkout-builtin.sh that would result in an
infinite loop and out-of-memory error before this change. The issue
relies on having non-cone-mode patterns while trying to modify the
patterns in cone-mode.
The fix is simple, allowing us to break from the loop when the input
path does not contain a slash, as the "dir" pattern we added does not.
This is only a fix to the critical out-of-memory error. A better
response to such a strange state will follow in a later change.
Reported-by: Calbabreaker <calbabreaker@gmail.com> Helped-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Thu, 16 Dec 2021 16:13:40 +0000 (16:13 +0000)]
sparse-checkout: fix segfault on malformed patterns
Then core.sparseCheckoutCone is enabled, the sparse-checkout patterns are
used to populate two hashsets that accelerate pattern matching. If the user
modifies the sparse-checkout file outside of the 'sparse-checkout' builtin,
then strange patterns can happen, triggering some error checks.
One of these error checks is possible to hit when some special characters
exist in a line. A warning message is correctly written to stderr, but then
there is additional logic that attempts to remove the line from the hashset
and free the data. This leads to a segfault in the 'git sparse-checkout
list' command because it iterates over the contents of the hashset, which is
now invalid.
The fix here is to stop trying to remove from the hashset. In addition,
we disable cone mode sparse-checkout because of the malformed data. This
results in the pattern-matching working with a possibly-slower
algorithm, but using the patterns as they are in the sparse-checkout
file.
This also changes the behavior of commands such as 'git sparse-checkout
list' because the output patterns will be the contents of the
sparse-checkout file instead of the list of directories. This is an
existing behavior for other types of bad patterns.
Add a test that triggers the segfault without the code change.
Reported-by: John Burnett <johnburnett@johnburnett.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Thu, 30 Dec 2021 20:18:35 +0000 (12:18 -0800)]
SubmittingPatchs: clarify choice of base and testing
We encourage identifying what, among many topics on `next`, exact
topics a new work depends on, instead of building directly on
`next`. Let's clarify this in the documentation.
Developers should know what they are building on top of, and be
aware of which part of the system is currently being worked on.
Encouraging them to make trial merges to `next` and `seen`
themselves will incentivize them to read others' changes and
understand them, eventually helping the developers to coordinate
among themselves and reviewing each others' changes.
projects / thirdparty / git.git / log
