Replace old-style `test -[df]` and `! test -[df]` assertions with
the modern `test_path_is_file`, `test_path_is_dir`, and
`test_path_is_missing` helpers.
These helpers provide more informative error messages in case of
failure (e.g., "File 'foo' is missing" instead of just exit code 1).
While at it, fix a typo and an incorrect path
reference in one of the test descriptions.
Signed-off-by: K Jayatheerth <jayatheerthkulkarni2005@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Import newer version of "clar", unit testing framework.
* ps/clar-integers:
gitattributes: disable blank-at-eof errors for clar test expectations
t/unit-tests: demonstrate use of integer comparison assertions
t/unit-tests: update clar to 39f11fe
Test coverage of "git replay" has been improved.
* kh/replay-invalid-onto-advance:
t3650: add more regression tests for failure conditions
replay: die if we cannot parse object
replay: improve code comment and die message
replay: die descriptively when invalid commit-ish is given
replay: find *onto only after testing for ref name
replay: remove dead code and rearrange
Miscellaneous fixes on object database layer.
* ps/odb-misc-fixes:
odb: properly close sources before freeing them
builtin/gc: fix condition for whether to write commit graphs
The ort merge machinery hit an assertion failure in a history with
criss-cross merges renamed a directory and a non-directory, which
has been corrected.
* en/ort-recursive-d-f-conflict-fix:
merge-ort: fix corner case recursive submodule/directory conflict handling
Running "git diff" with "--name-only" and other options that allows
us not to look at the blob contents, while objects that are lazily
fetched from a promisor remote, caused use-after-free, which has
been corrected.
* ds/diff-lazy-fetch-with-name-only-fix:
diff: avoid segfault with freed entries
This test indirectly checks that the lost-found folder has 2 files in it
and then checks that the expected two files exist. Make this more
deliberate by removing the old test -f and compare the actual ls of the
lost-found directory with the expected files.
Signed-off-by: Andrew Chitester <andchi@fastmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When performing auto-maintenance we check whether commit graphs need to
be generated by counting the number of commits that are reachable by any
reference, but not covered by a commit graph. This search is performed
by iterating through all references and then doing a depth-first search
until we have found enough commits that are not present in the commit
graph.
This logic has a memory leak though:
Direct leak of 16 byte(s) in 1 object(s) allocated from:
#0 0x55555562e433 in malloc (git+0xda433)
#1 0x555555964322 in do_xmalloc ../wrapper.c:55:8
#2 0x5555559642e6 in xmalloc ../wrapper.c:76:9
#3 0x55555579bf29 in commit_list_append ../commit.c:1872:35
#4 0x55555569f160 in dfs_on_ref ../builtin/gc.c:1165:4
#5 0x5555558c33fd in do_for_each_ref_iterator ../refs/iterator.c:431:12
#6 0x5555558af520 in do_for_each_ref ../refs.c:1828:9
#7 0x5555558ac317 in refs_for_each_ref ../refs.c:1833:9
#8 0x55555569e207 in should_write_commit_graph ../builtin/gc.c:1188:11
#9 0x55555569c915 in maintenance_is_needed ../builtin/gc.c:3492:8
#10 0x55555569b76a in cmd_maintenance ../builtin/gc.c:3542:9
#11 0x55555575166a in run_builtin ../git.c:506:11
#12 0x5555557502f0 in handle_builtin ../git.c:779:9
#13 0x555555751127 in run_argv ../git.c:862:4
#14 0x55555575007b in cmd_main ../git.c:984:19
#15 0x5555557523aa in main ../common-main.c:9:11
#16 0x7ffff7a2a4d7 in __libc_start_call_main (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x2a4d7) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
#17 0x7ffff7a2a59a in __libc_start_main@GLIBC_2.2.5 (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x2a59a) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
#18 0x5555555f0934 in _start (git+0x9c934)
The root cause of this memory leak is our use of `commit_list_append()`.
This function expects as parameters the item to append and the _tail_ of
the list to append. This tail will then be overwritten with the new tail
of the list so that it can be used in subsequent calls. But we call it
with `commit_list_append(parent->item, &stack)`, so we end up losing
everything but the new item.
This issue only surfaces when counting merge commits. Next to being a
memory leak, it also shows that we're in fact miscounting as we only
respect children of the last parent. All previous parents are discarded,
so their children will be disregarded unless they are hit via another
reference.
While crafting a test case for the issue I was puzzled that I couldn't
establish the proper border at which the auto-condition would be
fulfilled. As it turns out, there's another bug: if an object is at the
tip of any reference we don't mark it as seen. Consequently, if it is
the tip of or reachable via another ref, we'd count that object multiple
times.
Fix both of these bugs so that we properly count objects without leaking
any memory.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 8002e8ee18 (builtin/cat-file: use bitmaps to efficiently filter
by object type, 2025-04-02) introduced a performance regression when we
are not filtering objects: it uses bitmaps even when they won't help,
incurring extra costs. For example, running the new perf tests from this
commit, which check the performance of listing objects by oid:
$ export GIT_PERF_LARGE_REPO=/path/to/linux.git
$ git -C "$GIT_PERF_LARGE_REPO" repack -adb
$ GIT_SKIP_TESTS=p1006.1 ./run 8002e8ee18^ 8002e8ee18 p1006-cat-file.sh
[...]
Test 8002e8ee18^ 8002e8ee18
-------------------------------------------------------------------------------
1006.2: list all objects (sorted) 1.48(1.44+0.04) 6.39(6.35+0.04) +331.8%
1006.3: list all objects (unsorted) 3.01(2.97+0.04) 3.40(3.29+0.10) +13.0%
1006.4: list blobs 4.85(4.67+0.17) 1.68(1.58+0.10) -65.4%
An invocation that filters, like listing all blobs (1006.4), does
benefit from using the bitmaps; it now doesn't have to check the type of
each object from the pack data, so the tradeoff is worth it.
But for listing all objects in sorted idx order (1006.2), we otherwise
would never open the bitmap nor the revindex file. Worse, our sorting
step gets much worse. Normally we append into an array in pack .idx
order, and the sort step is trivial. But with bitmaps, we get the
objects in pack order, which is apparently random with respect to oid,
and have to sort the whole thing. (Note that this freshly-packed state
represents the best case for .idx sorting; if we had two packs, then
we'd have their objects one after the other and qsort would have to
interleave them).
The unsorted test in 1006.3 is interesting: there we are going in pack
order, so we load the revindex for the pack anyway. And though we don't
sort the result, we do use an oidset to check for duplicates. So we can
see in the 8002e8ee18^ timings that those two things cost ~1.5s over the
sorted case (mostly the oidset hash cost). We also incur the extra cost
to open the bitmap file as of 8002e8ee18, which seems to be ~400ms.
(This would probably be faster with a bitmap lookup table, but writing
that out is not yet the default).
So we know that bitmaps help when there's filtering to be done, but
otherwise make things worse. Let's only use them when there's a filter.
The perf script shows that we've fixed the regressions without hurting
the bitmap case:
Test 8002e8ee18^ 8002e8ee18 HEAD
--------------------------------------------------------------------------------------------------------
1006.2: list all objects (sorted) 1.56(1.53+0.03) 6.44(6.37+0.06) +312.8% 1.62(1.54+0.06) +3.8%
1006.3: list all objects (unsorted) 3.04(2.98+0.06) 3.45(3.38+0.07) +13.5% 3.04(2.99+0.04) +0.0%
1006.4: list blobs 5.14(4.98+0.15) 1.76(1.68+0.06) -65.8% 1.73(1.64+0.09) -66.3%
Note that there's another related case: we might have a filter that
cannot be used with bitmaps. That check is handled already for us in
for_each_bitmapped_object(), though we'd still load the bitmap and
revindex files pointlessly in that case. I don't think it can happen in
practice for cat-file, though, since it allows only blob:none,
blob:limit, and object:type filters, all of which work with bitmaps.
It would be easy-ish to insert an extra check like:
can_filter_bitmap(&opt->objects_filter);
into the conditional, but I didn't bother here. It would be redundant
with the call in for_each_bitmapped_object(), and the can_filter helper
function is static local in the bitmap code (so we'd have to make it
public).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you run:
GIT_PERF_LARGE_REPO=/some/path ./p1006-cat-file.sh
it will use the repo in /some/path. But if you use the "run" helper
script to aggregate and compare results, like this:
GIT_PERF_LARGE_REPO=/some/path ./run HEAD^ HEAD p1006-cat-file.sh
it will ignore that variable. This is because the presence of the
LARGE_REPO variable in GIT-BUILD-OPTIONS overrides what's in the
environment. This started with 4638e8806e (Makefile: use common template
for GIT-BUILD-OPTIONS, 2024-12-06), which now writes even empty
variables (though arguably it was wrong even before with a non-empty
value, as we generally prefer the environment to take precedence over
on-disk config).
We had the same problem in perf-lib.sh itself, and we hacked around it
with 32b74b9809 (perf: do allow `GIT_PERF_*` to be overridden again,
2025-04-04). That's what lets the direct invocation of "./p1006" work
above.
And in fact that was sufficient for "./run", too, until it started
loading GIT-BUILD-OPTIONS itself in 5756ccd181 (t/perf: fix benchmarks
with out-of-tree builds, 2025-04-28). Now it has the same problem: it
clobbers any incoming GIT_PERF options from the environment.
We can use the same hack here in the "run" script. It's quite ugly, but
it's just short enough that I don't think it's worth trying to factor it
out into a common shell library.
In the long run, we might consider teaching GIT-BUILD-OPTIONS to be more
gentle in overwriting existing entries. There are probably other
GIT_TEST_* variables which would need the same treatment. And if and
when we come up with a more complete solution, we can use it in both
spots.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using the perf suite's "run" helper in a vanilla build fails like this:
$ make && (cd t/perf && ./run p0000-perf-lib-sanity.sh)
=== Running 1 tests in this tree ===
perf 1 - test_perf_default_repo works: 1 2 3 ok
perf 2 - test_checkout_worktree works: 1 2 3 ok
ok 3 - test_export works
perf 4 - export a weird var: 1 2 3 ok
perf 5 - éḿíẗ ńöń-ÁŚĆÍÍ ćḧáŕáćẗéŕś: 1 2 3 ok
ok 6 - test_export works with weird vars
perf 7 - important variables available in subshells: 1 2 3 ok
perf 8 - test-lib-functions correctly loaded in subshells: 1 2 3 ok
# passed all 8 test(s)
1..8
cannot open test-results/p0000-perf-lib-sanity.subtests: No such file or directory at ./aggregate.perl line 159.
It is trying to aggregate results written into t/perf/test-results, but
the p0000 script did not write anything there.
The "run" script looks in $TEST_OUTPUT_DIRECTORY/test-results, or if
that variable is not set, in test-results in the current working
directory (which should be t/perf itself). It pulls the value of
$TEST_OUTPUT_DIRECTORY from the GIT-BUILD-OPTIONS file.
But that doesn't quite match the setup in perf-lib.sh (which is what
scripts like p0000 use). There we do this at the top of the script:
TEST_OUTPUT_DIRECTORY=$(pwd)
and then let test-lib.sh append "/test-results" to that. Historically,
that made the vanilla case work: we'd always use t/perf/test-results.
But when $TEST_OUTPUT_DIRECTORY was set, it would break.
Commit 5756ccd181 (t/perf: fix benchmarks with out-of-tree builds,
2025-04-28) fixed that second case by loading GIT-BUILD-OPTIONS
ourselves. But that broke the vanilla case!
Now our setting of $TEST_OUTPUT_DIRECTORY in perf-lib.sh is ignored,
because it is overwritten by GIT-BUILD-OPTIONS. And when test-lib.sh
sees that the output directory is empty, it defaults to t/test-results,
rather than t/perf/test-results.
Nobody seems to have noticed, probably for two reasons:
1. It only matters if you're trying to aggregate results (like the
"run" script does). Just running "./p0000-perf-lib-sanity.sh"
manually still produces useful output; the stored result files are
just in an unexpected place.
2. There might be leftover files in t/perf/test-results from previous
runs (before 5756ccd181). In particular, the ".subtests" files
don't tend to change, and the lack of that file is what causes it
to barf completely. So it's possible that the aggregation could
have been showing stale results that did not match the run that
just happened.
We can fix it by setting TEST_OUTPUT_DIRECTORY only after we've loaded
GIT-BUILD-OPTIONS, so that we override its value and not the other way
around. And we'll do so only when the variable is not set, which should
retain the fix for that case from 5756ccd181.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use hook API to replace ad-hoc invocation of hook scripts with the
run_command() API.
* ar/run-command-hook:
receive-pack: convert receive hooks to hook API
receive-pack: convert update hooks to new API
hooks: allow callers to capture output
run-command: allow capturing of collated output
hook: allow overriding the ungroup option
reference-transaction: use hook API instead of run-command
transport: convert pre-push to hook API
hook: convert 'post-rewrite' hook in sequencer.c to hook API
hook: provide stdin via callback
run-command: add stdin callback for parallelization
run-command: add first helper for pp child states
There isn’t much test coverage for basic failure conditions. Let’s add
a few more since these are simple to write and remove if they become
obsolete.
Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Giving an invalid commit-ish to `--onto` makes git-replay(1) fail with:
fatal: Replaying down to root commit is not supported yet!
Going backwards from this point:
1. `onto` is `NULL` from `set_up_replay_mode`;
2. that function in turn calls `peel_committish`; and
3. here we return `NULL` if `repo_get_oid` fails.
Let’s die immediately with a descriptive error message instead.
Doing this also provides us with a descriptive error if we “forget” to
provide an argument to `--onto` (but we really do unintentionally):[1]
$ git replay --onto ^main topic1
fatal: '^main' is not a valid commit-ish
Note that the `--advance` case won’t be triggered in practice because
of the “argument to --advance must be a reference” check (see the
previous test, and commit).
† 1: The argument to `--onto` is mandatory and the option parser accepts
both `--onto=<name>` (stuck form) and `--onto name`. The latter
form makes it easy to unintentionally pass something to the option
when you really meant to pass a positional argument.
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We are about to make `peel_committish` die when it cannot find
a commit-ish instead of returning `NULL`. But that would make e.g.
`git replay --advance=refs/non-existent` die with a less descriptive
error message; the highest-level error message is that the name does
not exist as a ref, not that we cannot find a commit-ish based on
the name.
Let’s try to find the ref and only after that try to peel to
as a commit-ish.
Also add a regression test to protect this error order from future
modifications.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up, unifying various hand-rolled "list of commit
objects" and use the commit_stack API.
* rs/commit-stack:
commit-reach: use commit_stack
commit-graph: use commit_stack
commit: add commit_stack_grow()
shallow: use commit_stack
pack-bitmap-write: use commit_stack
commit: add commit_stack_init()
test-reach: use commit_stack
remote: use commit_stack for src_commits
remote: use commit_stack for sent_tips
remote: use commit_stack for local_commits
name-rev: use commit_stack
midx: use commit_stack
log: use commit_stack
revision: export commit_stack
Diagnose invalid bundle-URI that lack the URI entry, instead of
crashing.
* sb/bundle-uri-without-uri:
bundle-uri: validate that bundle entries have a uri
More doc style updates.
* ja/doc-synopsis-style-more:
doc: convert git-remote to synopsis style
doc: convert git stage to use synopsis block
doc: convert git-status tables to AsciiDoc format
doc: convert git-status to synopsis style
doc: fix t0450-txt-doc-vs-help to select only first synopsis block
Replace `test -f` and `test -h` checks with `test_path_is_file` and
`test_path_is_symlink`. Using the test framework helpers provides
clearer diagnostics and keeps tests consistent across the suite.
Signed-off-by: Pushkar Singh <pushkarkumarsingh1970@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "difftool --dir-diff syncs worktree without unstaged change" test
fails intermittently on Windows CI, as seen at:
https://github.com/git/git/actions/runs/20624095002/job/59231745784#step:5:416
The root cause is that the original file content and the replacement
content have identical sizes:
- Original: "main\ntest\na\n" = 12 bytes
- New: "new content\n" = 12 bytes
When difftool's sync-back mechanism checks for changes, it compares
stat data between the temporary index and the modified files. If the
modification happens within the same timestamp granularity window and
file size stays the same, the change goes undetected.
On Windows, this is more likely to manifest because Git relies on
inode changes as a fallback when other stat fields match, but Windows
filesystems lack inodes. This is a real bug that could affect users
scripting difftool similarly, as seen at:
https://github.com/git-for-windows/git/issues/5132
Fix the test by changing the replacement content to "modified content"
(17 bytes), ensuring the size difference is detected regardless of
timestamp resolution or platform-specific stat behavior.
Note: This fixes the test flakiness but not the underlying issue in
difftool's change detection. Other tests with same-size file patterns
(t0010-racy-git.sh, t2200-add-update.sh) are not affected because they
use normal index operations with proper racy-git detection.
Signed-off-by: Paul Tarjan <github@paulisageek.com>
Reviewed-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The ort merge machinery was hit an assertion failure in a history
with criss-cross merges renamed a directory and a non-directory,
which has been corrected.
* en/ort-recursive-d-f-conflict-fix:
merge-ort: fix corner case recursive submodule/directory conflict handling
Running "git diff" with "--name-only" and other options that allows
us not to look at the blob contents, while objects that are lazily
fetched from a promisor remote, caused use-after-free, which has
been corrected.
* ds/diff-lazy-fetch-with-name-only-fix:
diff: avoid segfault with freed entries
Update HTTP tests to adjust for changes in curl 8.18.0
* jk/test-curl-updates:
t5563: add missing end-of-line in HTTP header
t5551: handle trailing slashes in expected cookies output
Even when there is no changes in the packfile and no need to
recompute bitmaps, "git repack" recomputed and updated the MIDX
file, which has been corrected.
* ps/repack-avoid-noop-midx-rewrite:
midx-write: skip rewriting MIDX with `--stdin-packs` unless needed
midx-write: extract function to test whether MIDX needs updating
midx: fix `BUG()` when getting preferred pack without a reverse index
Prepare test suite for Git for Windows that supports symbolic
links.
* js/test-symlink-windows:
t7800: work around the MSYS path conversion on Windows
t6423: introduce Windows-specific handling for symlinking to /dev/null
t1305: skip symlink tests that do not apply to Windows
t1006: accommodate for symlink support in MSYS2
t0600: fix incomplete prerequisite for a test case
t0301: another fix for Windows compatibility
t0001: handle `diff --no-index` gracefully
mingw: special-case `open(symlink, O_CREAT | O_EXCL)`
apply: symbolic links lack a "trustable executable bit"
t9700: accommodate for Windows paths
More object database related information are shown in "git repo
structure" output.
* jt/repo-struct-more-objinfo:
builtin/repo: add object disk size info to structure table
builtin/repo: add disk size info to keyvalue stucture output
builtin/repo: add inflated object info to structure table
builtin/repo: add inflated object info to keyvalue structure output
builtin/repo: humanise count values in structure output
strbuf: split out logic to humanise byte values
builtin/repo: group per-type object values into struct
When computing a diff in a partial clone, there is a chance that we
could trigger a prefetch of missing objects at the same time as we are
freeing entries from the global diff queue. This is difficult to
reproduce, as we need to have some objects be freed from the queue
before triggering the prefetch of missing objects. There is a new test
in t4067 that does trigger the segmentation fault that results in this
case.
The fix is to set the queue pointer to NULL after it is freed, and then
to be careful about NULL values in the prefetch.
The more elaborate explanation is that within diffcore_std(), we may
skip the initial prefetch due to the output format (--name-only in the
test) and go straight to diffcore_skip_stat_unmatch(). In that method,
the index entries that have been invalidated by path changes show up as
entries but may be deleted because they are not actually content diffs
and only newer timestamps than expected. As those entries are deleted,
later entries are checked with diff_filespec_check_stat_unmatch(), which
uses diff_queued_diff_prefetch() as the missing_object_cb in its diff
options. That can trigger downloading missing objects if the appropriate
scenario occurs to trigger a call to diff_popoulate_filespec(). It's
finally within that callback to diff_queued_diff_prefetch() that the
segfault occurs.
The test was hard to find because it required some real differences,
some not-different files that had a newer modified time, and the order
of those files alphabetically was important to trigger the deletion
before the prefetch was triggered.
I briefly considered a "lock" member for the diff queue, but it was a
much larger diff and introduced many more possible error scenarios.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace 'test -f' with the test_path_is_file in
t5403-post-checkout-hook.sh. This helper provides better error
messages when tests fail, making it easier to debug issues.
Signed-off-by: Deveshi Dwivedi <deveshigurgaon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
At GitHub, a few repositories were triggering errors of the form:
git: merge-ort.c:3037: process_renames: Assertion `newinfo && !newinfo->merged.clean' failed.
Aborted (core dumped)
While these may look similar to both
a562d90a350d (merge-ort: fix failing merges in special corner case,
2025-11-03)
and
f6ecb603ff8a (merge-ort: fix directory rename on top of source of other
rename/delete, 2025-08-06)
the cause is different and in this case the problem is not an
over-conservative assertion, but a bug before the assertion where we did
not update all relevant state appropriately.
It sadly took me a really long time to figure out how to get a simple
reproducer for this one. It doesn't really have that many moving parts,
but there are multiple pieces of background information needed to
understand it.
First of all, when we have two files added at the same path, merge-ort
does a two-way merge of those files. If we have two directories added
at the same path, we basically do the same thing (taking the union of
files, and two-way merging files with the same name). But two-way
merging requires components of the same type. We can't merge the
contents of a regular file with a directory, or with a symlink, or with
a submodule. Nor can any of those other types be merged with each
other, e.g. merging a submodule with a directory is a bad idea. When
two paths have the same name but their types do not match, merge-ort is
forced to move one of them to an alternate filename (using the
unique_path() function).
Second, if two commits being merged have more than one merge-base,
merge-ort will merge the merge-bases to create a virtual merge-base, and
use that as the base commit.
Third, one of the really important optimizations in merge-ort is trivial
tree-level resolution (roughly meaning merging trees without recursing
into them). This optimization has some nuance to it that is important
to the current bug, and to understand it, it helps to first look at the
high-level overview of how merge-ort runs; there are basically three
high-level functions that the work is divided between:
collect_merge_info() - walks the top-level trees getting individual
paths of interest
detect_renames() - detect renames between paths in order to match up
paths for three-way merging
process_entries() - does a few things of interest:
* three-way merging of files,
* other special handling (e.g. adjusting paths with conflicting
types to avoid path collisions)
* as it finishes handling all the files within a subdirectory,
writes out a new tree object for that directory
If it were not for renames, we could just always do tree-level merging
whenever the tree on at least one side was unmodified. Unfortunately,
we need to recurse into trees to determine whether there are renames.
However, we can also do tree-level merging so long as there aren't any
*relevant* renames (another merge-ort optimization), which we can
determine without recursing into trees.
We would also be able to do tree-level merging if we somehow apriori
knew what renames existed, by only recursing into the trees which we
could otherwise trivially merge if they contained files involved in
renames. That might not seem useful, because we need to find out the
renames and we have to recurse into trees to do so, but when you find
out that the process_entries() step is more computationally expensive
than the collect_merge_info() step, it yields an interesting strategy:
* run collect_merge_info()
* run detect_renames()
* cache the renames()
* restart -- rerun collect_merge_info(), using the cached renames to
only recurse into the needed trees
* we already have the renames cached so no need to re-detect
* run process_entries() on the reduced list of paths
which was implemented back in 7bee6c100431 (merge-ort: avoid recursing
into directories when we don't need to, 2021-07-16) Crucially, this
restarting only occurs if the number of paths we could skip recursing
into exceeds the number we still need to recurse into by some safety
factor (wanted_factor in handle_deferred_entries()); forgetting this
fact is a great way to repeatedly fail to create a minimal testcase for
several days and go down alternate wrong paths).
Now, I earlier summarized this optimization as "merging trees without
recursing into them", but this optimization does not require that all
three sides of history has a directory at a given path. So long as the
tree on one side matches the tree in the base version, we can decide to
resolve in favor of whatever the other side of history has at that path
-- be it a directory, a file, a submodule, or a symlink. Unfortunately,
the code in question didn't fully realize this, and was written assuming
the base version and both sides would have a directory at the given
path, as can be seen by the "ci->filemask == 0" comment in
resolve_trivial_directory_merge() that was added as part of 7bee6c100431
(merge-ort: avoid recursing into directories when we don't need to,
2021-07-16). A few additional lines of code are needed to handle cases
where we have something other than a directory on the other side of
history.
But, knowing that resolve_trivial_directory_merge() doesn't have
sufficient state updating logic doesn't show us how to trigger a bug
without combining with the other bits of information we provided above.
Here's a relevant testcase:
* branches A & B
* commit A1: adds "folder" as a directory with files tracked under it
* commit B1: adds "folder" as a submodule
* commit A2: merges B1 into A1, keeping "folder" as a directory
(and in fact, with no changes to "folder" since A1), discarding the
submodule
* commit B2: merges A1 into B1, keeping "folder" as a submodule
(and in fact, with no changes to "folder" since B1), discarding the
directory
Here, if we try to merge A2 & B2, the logic proceeds as follows:
* we have multiple merge-bases: A1 & B1. So we have to merge those
to get a virtual merge base.
* due to "folder" as a directory and "folder" as a submodule, the
path collision logic triggers and renames "folder" as a submodule
to "folder~Temporary merge branch 2" so we can keep it alongside
"folder" as a directory.
* we now have a virtual merge base (containing both "folder"
directory and a "folder~Temporary merge branch 2" submodule) and
can now do the outer merge
* in the first step of the outer merge, we attempt to defer recursing
into folder/ as a directory, but find we need to for rename
detection.
* in rename detection, we note that "folder~Temporary merge branch 2"
has the same hash as "folder" as a submodule in B2, which means we
have an exact rename.
* after rename detection, we discover no path in folder/ is needed
for renames, and so we can cache renames and restart.
* after restarting, we avoid recursing into "folder/" and realize we
can resolve it trivially since it hasn't been modified. The
resolution removes "folder/", leaving us only "folder" as a
submodule from commit B2.
* After this point, we should have a rename/delete conflict on
"folder~Temporary merge branch 2" -> "folder", but our marking of
the merge of "folder" as clean broke our ability to handle that and
in fact triggers an assertion in process_renames().
When there was a df_conflict (directory/"file" conflict, where "file"
could be submodule or regular file or symlink), ensure
resolve_trivial_directory_merge() handles it properly. In particular:
* do not pre-emptively mark the path as cleanly merged if the
remaining path is a file; allow it to be processed in
process_entries() later to determine if it was clean
* clear the parts of dirmask or filemask corresponding to the matching
sides of history, since we are resolving those away
* clear the df_conflict bit afterwards; since we cleared away the two
matching sides and only have one side left, that one side can't
have a directory/file conflict with itself.
Also add the above minimal testcase showcasing this bug to t6422, **with
a sufficient number of paths under the folder/ directory to actually
trigger it**. (I wish I could have all those days back from all the
wrong paths I went down due to not having enough files under that
directory...)
I know this commit has a very high ratio of lines in the commit message
to lines of comments, and a relatively high ratio of comments to actual
code, but given how long it took me to track down, on the off chance
that we ever need to further modify this logic, I wanted it thoroughly
documented for future me and for whatever other poor soul might end up
needing to read this commit message.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use hook API to replace ad-hoc invocation of hook scripts with the
run_command() API.
* ar/run-command-hook:
receive-pack: convert receive hooks to hook API
receive-pack: convert update hooks to new API
hooks: allow callers to capture output
run-command: allow capturing of collated output
hook: allow overriding the ungroup option
reference-transaction: use hook API instead of run-command
transport: convert pre-push to hook API
hook: convert 'post-rewrite' hook in sequencer.c to hook API
hook: provide stdin via callback
run-command: add stdin callback for parallelization
run-command: add first helper for pp child states
Some callers, for example server-side hooks which wish to relay hook
output to clients across a transport, want to capture what would
normally print to stderr and do something else with it. Allow that via a
callback.
By calling the callback regardless of whether there's output available,
we allow clients to send e.g. a keepalive if necessary.
Because we expose a strbuf, not a fd or FILE*, there's no need to create
a temporary pipe or similar - we can just skip the print to stderr and
instead hand it to the caller.
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a user of the run_processes_parallel() API wants to pipe a large
amount of information to the stdin of each parallel command, that
data could exceed the pipe buffer of the process's stdin and can be
too big to store in-memory via strbuf & friends or to slurp to a file.
Generally this is solved by repeatedly writing to child_process.in
between calls to start_command() and finish_command(). For a specific
pre-existing example of this, see transport.c:run_pre_push_hook().
This adds a generic callback API to run_processes_parallel() to do
exactly that in a unified manner, similar to the existing callback APIs,
which can then be used by hooks.h to convert the remaining hooks to the
new, simpler parallel interface.
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Building a list using commit_list_insert_by_date() has quadratic worst
case complexity. Avoid it by using prio_queue.
Use prio_queue_peek()+prio_queue_replace() instead of prio_queue_get()+
prio_queue_put() if possible, as the former only rebalance the
prio_queue heap once instead of twice.
In sane repositories this won't make much of a difference because the
number of items in the list or queue won't be very high:
Benchmark 1: ./git_v2.52.0 show-branch origin/main origin/next origin/seen origin/todo
Time (mean ± σ): 538.2 ms ± 0.8 ms [User: 527.6 ms, System: 9.6 ms]
Range (min … max): 537.0 ms … 539.2 ms 10 runs
Benchmark 2: ./git show-branch origin/main origin/next origin/seen origin/todo
Time (mean ± σ): 530.6 ms ± 0.4 ms [User: 519.8 ms, System: 9.8 ms]
Range (min … max): 530.1 ms … 531.3 ms 10 runs
Summary
./git show-branch origin/main origin/next origin/seen origin/todo ran
1.01 ± 0.00 times faster than ./git_v2.52.0 show-branch origin/main origin/next origin/seen origin/todo
That number is not limited, though, and in pathological cases like the
one in p6010 we see a sizable improvement:
Test v2.52.0 HEAD
------------------------------------------------------------------
6010.4: git show-branch 2.19(2.19+0.00) 0.03(0.02+0.00) -98.6%
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update HTTP tests to adjust for changes in curl 8.18.0
* jk/test-curl-updates:
t5563: add missing end-of-line in HTTP header
t5551: handle trailing slashes in expected cookies output
"git fetch" that involves fetching tags, when a tag being fetched
needs to overwrite existing one, failed to fetch other tags, which
has been corrected.
* kn/fix-fetch-backfill-tag-with-batched-ref-updates:
fetch: fix failed batched updates skipping operations
fetch: fix non-conflicting tags not being committed
fetch: extract out reference committing logic
"git diff-files -R --find-copies-harder" has been taught to use
the potential copy sources from the index correctly.
* rs/diff-files-r-find-copies-fix:
diff-files: fix copy detection
"git submodule add" to add a submodule under <name> segfaulted,
when a submodule.<name>.something is already in .gitmodules file
without defining where its submodule.<name>.path is, which has been
corrected.
* jc/submodule-add:
submodule add: sanity check existing .gitmodules
