Commit Graph

67953 Commits

Author SHA1 Message Date
Junio C Hamano
a6b42ec0c6 Merge branch 'jk/unused-annotation'
Annotate function parameters that are not used (but cannot be
removed for structural reasons), to prepare us to later compile
with -Wunused warning turned on.

* jk/unused-annotation:
  is_path_owned_by_current_uid(): mark "report" parameter as unused
  run-command: mark unused async callback parameters
  mark unused read_tree_recursive() callback parameters
  hashmap: mark unused callback parameters
  config: mark unused callback parameters
  streaming: mark unused virtual method parameters
  transport: mark bundle transport_options as unused
  refs: mark unused virtual method parameters
  refs: mark unused reflog callback parameters
  refs: mark unused each_ref_fn parameters
  git-compat-util: add UNUSED macro
2022-09-14 12:56:39 -07:00
Junio C Hamano
e188ec3a73 Sync with 'maint' 2022-09-13 12:23:48 -07:00
Junio C Hamano
a0feb8611d Merge a handful of topics from the 'master' front
As the 'master' front will soon tag a preview and then release
candidates for 2.38, it is unknown if we are going to issue another
maintenance release on the 2.37.x track, but as we have accumulated
enough material there, let's prepare a draft for it.

Even if we end up not tagging 2.37.4, it would help motivated distro
packagers to maintain their slightly older and "more stable" versions.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-13 12:22:59 -07:00
Junio C Hamano
2c75b3255b Merge branch 'en/merge-unstash-only-on-clean-merge' into maint
The auto-stashed local changes created by "git merge --autostash"
was mixed into a conflicted state left in the working tree, which
has been corrected.

* en/merge-unstash-only-on-clean-merge:
  merge: only apply autostash when appropriate
2022-09-13 12:21:11 -07:00
Junio C Hamano
4f06dfde7a Merge branch 'ds/github-actions-use-newer-ubuntu' into maint
Update the version of Ubuntu used for GitHub Actions CI from 18.04
to 22.04.

* ds/github-actions-use-newer-ubuntu:
  ci: update 'static-analysis' to Ubuntu 22.04
2022-09-13 12:21:10 -07:00
Junio C Hamano
37317ab40b Merge branch 'ad/preload-plug-memleak' into maint
The preload-index codepath made copies of pathspec to give to
multiple threads, which were left leaked.

* ad/preload-plug-memleak:
  preload-index: fix memleak
2022-09-13 12:21:10 -07:00
Junio C Hamano
c61614e30f Merge branch 'sg/xcalloc-cocci-fix' into maint
xcalloc(), imitating calloc(), takes "number of elements of the
array", and "size of a single element", in this order.  A call that
does not follow this ordering has been corrected.

* sg/xcalloc-cocci-fix:
  promisor-remote: fix xcalloc() argument order
2022-09-13 12:21:09 -07:00
Junio C Hamano
aa31cb8974 Merge branch 'jk/pipe-command-nonblock' into maint
Fix deadlocks between main Git process and subprocess spawned via
the pipe_command() API, that can kill "git add -p" that was
reimplemented in C recently.

* jk/pipe-command-nonblock:
  pipe_command(): mark stdin descriptor as non-blocking
  pipe_command(): handle ENOSPC when writing to a pipe
  pipe_command(): avoid xwrite() for writing to pipe
  git-compat-util: make MAX_IO_SIZE define globally available
  nonblock: support Windows
  compat: add function to enable nonblocking pipes
2022-09-13 12:21:08 -07:00
Junio C Hamano
72869e750b Merge branch 'jk/is-promisor-object-keep-tree-in-use' into maint
An earlier optimization discarded a tree-object buffer that is
still in use, which has been corrected.

* jk/is-promisor-object-keep-tree-in-use:
  is_promisor_object(): fix use-after-free of tree buffer
2022-09-13 12:21:07 -07:00
Junio C Hamano
21dd13e025 The twentieth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-13 11:38:25 -07:00
Junio C Hamano
de1fee2f1e Merge branch 'ow/rev-parse-parseopt-fix'
The parser in the script interface to parse-options in "git
rev-parse" has been updated to diagnose a bogus input correctly.

* ow/rev-parse-parseopt-fix:
  rev-parse --parseopt: detect missing opt-spec
2022-09-13 11:38:25 -07:00
Junio C Hamano
e4ffba458f Merge branch 'js/builtin-add-p-portability-fix'
More fixes to "add -p"

* js/builtin-add-p-portability-fix:
  t6132(NO_PERL): do not run the scripted `add -p`
  t3701: test the built-in `add -i` regardless of NO_PERL
  add -p: avoid ambiguous signed/unsigned comparison
2022-09-13 11:38:24 -07:00
Junio C Hamano
76ffa818c7 Merge branch 'sg/parse-options-subcommand'
The codepath for the OPT_SUBCOMMAND facility has been cleaned up.

* sg/parse-options-subcommand:
  notes, remote: show unknown subcommands between `'
  notes: simplify default operation mode arguments check
  test-parse-options.c: fix style of comparison with zero
  test-parse-options.c: don't use for loop initial declaration
  t0040-parse-options: remove leftover debugging
2022-09-13 11:38:24 -07:00
Junio C Hamano
655e494047 Merge branch 'jk/rev-list-verify-objects-fix'
"git rev-list --verify-objects" ought to inspect the contents of
objects and notice corrupted ones, but it didn't when the commit
graph is in use, which has been corrected.

* jk/rev-list-verify-objects-fix:
  rev-list: disable commit graph with --verify-objects
  lookup_commit_in_graph(): use prepare_commit_graph() to check for graph
2022-09-13 11:38:24 -07:00
Junio C Hamano
8b2f027e20 Merge branch 'jk/upload-pack-skip-hash-check'
The server side that responds to "git fetch" and "git clone"
request has been optimized by allowing it to send objects in its
object store without recomputing and validating the object names.

* jk/upload-pack-skip-hash-check:
  t1060: check partial clone of misnamed blob
  parse_object(): check commit-graph when skip_hash set
  upload-pack: skip parse-object re-hashing of "want" objects
  parse_object(): allow skipping hash check
2022-09-13 11:38:23 -07:00
Junio C Hamano
e0574c4fd1 Merge branch 'rs/diff-no-index-cleanup'
"git diff --no-index A B" managed its the pathnames of its two
input files rather haphazardly, sometimes leaking them.  The
command line argument processing has been straightened out to clean
it up.

* rs/diff-no-index-cleanup:
  diff-no-index: simplify argv index calculation
  diff-no-index: release prefixed filenames
  diff-no-index: release strbuf on queue error
2022-09-13 11:38:23 -07:00
Junio C Hamano
f322e9f51b Merge branch 'ab/submodule-helper-prep'
Code clean-up of "git submodule--helper".

* ab/submodule-helper-prep: (33 commits)
  submodule--helper: fix bad config API usage
  submodule--helper: libify even more "die" paths for module_update()
  submodule--helper: libify more "die" paths for module_update()
  submodule--helper: check repo{_submodule,}_init() return values
  submodule--helper: libify "must_die_on_failure" code paths (for die)
  submodule--helper update: don't override 'checkout' exit code
  submodule--helper: libify "must_die_on_failure" code paths
  submodule--helper: libify determine_submodule_update_strategy()
  submodule--helper: don't exit() on failure, return
  submodule--helper: use "code" in run_update_command()
  submodule API: don't handle SM_..{UNSPECIFIED,COMMAND} in to_string()
  submodule--helper: don't call submodule_strategy_to_string() in BUG()
  submodule--helper: add missing braces to "else" arm
  submodule--helper: return "ret", not "1" from update_submodule()
  submodule--helper: rename "int res" to "int ret"
  submodule--helper: don't redundantly check "else if (res)"
  submodule--helper: refactor "errmsg_str" to be a "struct strbuf"
  submodule--helper: add "const" to passed "struct update_data"
  submodule--helper: add "const" to copy of "update_data"
  submodule--helper: add "const" to passed "module_clone_data"
  ...
2022-09-13 11:38:23 -07:00
Junio C Hamano
0479138645 Merge branch 'ed/fsmonitor-on-network-disk'
The built-in fsmonitor refuses to work on a network mounted
repositories; a configuration knob for users to override this has
been introduced.

* ed/fsmonitor-on-network-disk:
  fsmonitor: option to allow fsmonitor to run against network-mounted repos
2022-09-13 11:38:23 -07:00
Junio C Hamano
dd3f6c4cae The nineteenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-09 12:02:26 -07:00
Junio C Hamano
fe3939bc2a Merge branch 'vd/sparse-reset-checkout-fixes'
Segfault fix-up to an earlier fix to the topic to teach "git reset"
and "git checkout" work better in a sparse checkout.

* vd/sparse-reset-checkout-fixes:
  unpack-trees: fix sparse directory recursion check
2022-09-09 12:02:26 -07:00
Junio C Hamano
fd1ec82547 Merge branch 'ab/retire-ppc-sha1'
Remove the assembly version of SHA-1 implementation for PPC.

* ab/retire-ppc-sha1:
  Makefile: use $(OBJECTS) instead of $(C_OBJ)
  Makefile + hash.h: remove PPC_SHA1 implementation
2022-09-09 12:02:25 -07:00
Junio C Hamano
00b0199c51 Merge branch 'cc/doc-trailer-whitespace-rules'
Doc update.

* cc/doc-trailer-whitespace-rules:
  Documentation: clarify whitespace rules for trailers
2022-09-09 12:02:25 -07:00
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
428dce9f4d Merge branch 'js/range-diff-with-pathspec'
Allow passing a pathspec to "git range-diff".

* js/range-diff-with-pathspec:
  range-diff: optionally accept pathspecs
  range-diff: consistently validate the arguments
  range-diff: reorder argument handling
2022-09-09 12:02:25 -07:00
Junio C Hamano
526c4906f8 Merge branch 'jk/tempfile-active-flag-cleanup'
Code clean-up.

* jk/tempfile-active-flag-cleanup:
  tempfile: update comment describing state transitions
  tempfile: drop active flag
2022-09-09 12:02:24 -07:00
Junio C Hamano
fb094cb583 Merge branch 'js/add-p-diff-parsing-fix'
Those who use diff-so-fancy as the diff-filter noticed a regression
or two in the code that parses the diff output in the built-in
version of "add -p", which has been corrected.

* js/add-p-diff-parsing-fix:
  add -p: ignore dirty submodules
  add -p: gracefully handle unparseable hunk headers in colored diffs
  add -p: detect more mismatches between plain vs colored diffs
2022-09-09 12:02:24 -07:00
Øystein Walle
f20b9c36d0 rev-parse --parseopt: detect missing opt-spec
After 2d893dff4c (rev-parse --parseopt: allow [*=?!] in argument hints,
2015-07-14) updated the parser, a line in parseopts's input can start
with one of the flag characters and be erroneously parsed as a opt-spec
where the short name of the option is the flag character itself and the
long name is after the end of the string. This makes Git want to
allocate SIZE_MAX bytes of memory at this line:

    o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);

Since s and sb.buf are equal the second argument is -2 (except unsigned)
and xmemdupz allocates len + 1 bytes, ie. -1 meaning SIZE_MAX.

Avoid this by checking whether a flag character was found in the zeroth
position.

Reported-by: Ingy dot Net <ingy@ingy.net>
Signed-off-by: Øystein Walle <oystwa@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-08 14:55:07 -07:00
Jeff King
945ed00957 t1060: check partial clone of misnamed blob
A recent commit (upload-pack: skip parse-object re-hashing of "want"
objects, 2022-09-06) loosened the behavior of upload-pack so that it
does not verify the sha1 of objects it receives directly via "want"
requests. The existing corruption tests in t1060 aren't affected by
this: the corruptions are blobs reachable from commits, and the client
requests the commits.

The more interesting case here is a partial clone, where the client will
directly ask for the corrupted blob when it does an on-demand fetch of
the filtered object. And that is not covered at all, so let's add a
test.

It's important here that we use the "misnamed" corruption and not
"bit-error". The latter is sufficiently corrupted that upload-pack
cannot even figure out the type of the object, so it bails identically
both before and after the recent change. But with "misnamed", with the
hash-checks enabled it sees the problem (though the error messages are a
bit confusing because of the inability to create a "struct object" to
store the flags):

  error: hash mismatch d95f3ad14dee633a758d2e331151e950dd13e4ed
  fatal: git upload-pack: not our ref d95f3ad14dee633a758d2e331151e950dd13e4ed
  fatal: remote error: upload-pack: not our ref d95f3ad14dee633a758d2e331151e950dd13e4ed

After the change to skip the hash check, the server side happily sends
the bogus object, but the client correctly realizes that it did not get
the necessary data:

  remote: Enumerating objects: 1, done.
  remote: Counting objects: 100% (1/1), done.
  remote: Total 1 (delta 0), reused 0 (delta 0), pack-reused 0
  Receiving objects: 100% (1/1), 49 bytes | 49.00 KiB/s, done.
  fatal: bad revision 'd95f3ad14dee633a758d2e331151e950dd13e4ed'
  error: [...]/misnamed did not send all necessary objects

which is exactly what we expect to happen.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 15:08:51 -07:00
René Scharfe
2b43dd0eb5 diff-no-index: simplify argv index calculation
Since 16bb3d714d (diff --no-index: use parse_options() instead of
diff_opt_parse(), 2019-03-24) argc must be 2 if we reach the loop, i.e.
argc - 2 == 0.  Remove that inconsequential term.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:36:43 -07:00
René Scharfe
07a6f94a6d diff-no-index: release prefixed filenames
Callers of prefix_filename() are responsible for freeing its result.
Remember the returned strings and release them to appease leak checkers.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:34:03 -07:00
René Scharfe
fffe7d81a4 diff-no-index: release strbuf on queue error
The strbuf is small and we are about to exit, so we could leave its
cleanup to the OS.  If we release it explicitly at all, however, then we
should do it on early exit as well.  Move the strbuf_release call to a
new cleanup section at the end and make sure all execution paths go
through it.

Suggested-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:33:28 -07:00
Jeff King
9a8c3c4a5f parse_object(): check commit-graph when skip_hash set
If the caller told us that they don't care about us checking the object
hash, then we're free to implement any optimizations that get us the
parsed value more quickly. An obvious one is to check the commit graph
before loading an object from disk. And in fact, both of the callers who
pass in this flag are already doing so before they call parse_object()!

So we can simplify those callers, as well as any possible future ones,
by moving the logic into parse_object().

There are two subtle things to note in the diff, but neither has any
impact in practice:

  - it seems least-surprising here to do the graph lookup on the
    git-replace'd oid, rather than the original. This is in theory a
    change of behavior from the earlier code, as neither caller did a
    replace lookup itself. But in practice it doesn't matter, as we
    disable the commit graph entirely if there are any replace refs.

  - the caller in get_reference() passes the skip_hash flag only if
    revs->verify_objects isn't set, whereas it would look in the commit
    graph unconditionally. In practice this should not matter as we
    should disable the commit graph entirely when using verify_objects
    (and that was done recently in another patch).

So this should be a pure cleanup with no behavior change.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:27:02 -07:00
Jeff King
0bc2557951 upload-pack: skip parse-object re-hashing of "want" objects
Imagine we have a history with commit C pointing to a large blob B.
If a client asks us for C, we can generally serve both objects to them
without accessing the uncompressed contents of B. In upload-pack, we
figure out which commits we have and what the client has, and feed those
tips to pack-objects. In pack-objects, we traverse the commits and trees
(or use bitmaps!) to find the set of objects needed, but we never open
up B. When we serve it to the client, we can often pass the compressed
bytes directly from the on-disk packfile over the wire.

But if a client asks us directly for B, perhaps because they are doing
an on-demand fetch to fill in the missing blob of a partial clone, we
end up much slower. Upload-pack calls parse_object() on the oid we
receive, which opens up the object and re-checks its hash (even though
if it were a commit, we might skip this parse entirely in favor of the
commit graph!). And then we feed the oid directly to pack-objects, which
again calls parse_object() and opens the object. And then finally, when
we write out the result, we may send bytes straight from disk, but only
after having unnecessarily uncompressed and computed the sha1 of the
object twice!

This patch teaches both code paths to use the new SKIP_HASH_CHECK flag
for parse_object(). You can see the speed-up in p5600, which does a
blob:none clone followed by a checkout. The savings for git.git are
modest:

  Test                          HEAD^             HEAD
  ----------------------------------------------------------------------
  5600.3: checkout of result    2.23(4.19+0.24)   1.72(3.79+0.18) -22.9%

But the savings scale with the number of bytes. So on a repository like
linux.git with more files, we see more improvement (in both absolute and
relative numbers):

  Test                          HEAD^                HEAD
  ----------------------------------------------------------------------------
  5600.3: checkout of result    51.62(77.26+2.76)    34.86(61.41+2.63) -32.5%

And here's an even more extreme case. This is the android gradle-plugin
repository, whose tip checkout has ~3.7GB of files:

  Test                          HEAD^               HEAD
  --------------------------------------------------------------------------
  5600.3: checkout of result    79.51(90.84+5.55)   40.28(51.88+5.67) -49.3%

Keep in mind that these timings are of the whole checkout operation. So
they count the client indexing the pack and actually writing out the
files. If we want to see just the server's view, we can hack up the
GIT_TRACE_PACKET output from those operations and replay it via
upload-pack. For the gradle example, that gives me:

  Benchmark 1: GIT_PROTOCOL=version=2 git.old upload-pack ../gradle-plugin <input
    Time (mean ± σ):     50.884 s ±  0.239 s    [User: 51.450 s, System: 1.726 s]
    Range (min … max):   50.608 s … 51.025 s    3 runs

  Benchmark 2: GIT_PROTOCOL=version=2 git.new upload-pack ../gradle-plugin <input
    Time (mean ± σ):      9.728 s ±  0.112 s    [User: 10.466 s, System: 1.535 s]
    Range (min … max):    9.618 s …  9.842 s    3 runs

  Summary
    'GIT_PROTOCOL=version=2 git.new upload-pack ../gradle-plugin <input' ran
      5.23 ± 0.07 times faster than 'GIT_PROTOCOL=version=2 git.old upload-pack ../gradle-plugin <input'

So a server would see an 80% reduction in CPU serving the initial
checkout of a partial clone for this repository. Or possibly even more
depending on the packing; most of the time spent in the faster one were
objects we had to open during the write phase.

In both cases skipping the extra hashing on the server should be pretty
safe. The client doesn't trust the server anyway, so it will re-hash all
of the objects via index-pack. There is one thing to note, though: the
change in get_reference() affects not just pack-objects, but rev-list,
git-log, etc. We could use a flag to limit to index-pack here, but we
may already skip hash checks in this instance. For commits, we'd skip
anything we load via the commit-graph. And while before this commit we
would check a blob fed directly to rev-list on the command-line, we'd
skip checking that same blob if we found it by traversing a tree.

The exception for both is if --verify-objects is used. In that case,
we'll skip this optimization, and the new test makes sure we do this
correctly.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:20:02 -07:00
Jeff King
c868d8e91f parse_object(): allow skipping hash check
The parse_object() function checks the object hash of any object it
parses. This is a nice feature, as it means we may catch bit corruption
during normal use, rather than waiting for specific fsck operations.

But it also can be slow. It's particularly noticeable for blobs, where
except for the hash check, we could return without loading the object
contents at all. Now one may wonder what is the point of calling
parse_object() on a blob in the first place then, but usually it's not
intentional: we were fed an oid from somewhere, don't know the type, and
want an object struct. For commits and trees, the parsing is usually
helpful; we're about to look at the contents anyway. But this is less
true for blobs, where we may be collecting them as part of a
reachability traversal, etc, and don't actually care what's in them. And
blobs, of course, tend to be larger.

We don't want to just throw out the hash-checks for blobs, though. We do
depend on them in some circumstances (e.g., rev-list --verify-objects
uses parse_object() to check them). It's only the callers that know
how they're going to use the result. And so we can help them by
providing a special flag to skip the hash check.

We could just apply this to blobs, as they're going to be the main
source of performance improvement. But if a caller doesn't care about
checking the hash, we might as well skip it for other object types, too.
Even though we can't avoid reading the object contents, we can still
skip the actual hash computation.

If this seems like it is making Git a little bit less safe against
corruption, it may be. But it's part of a series of tradeoffs we're
already making. For instance, "rev-list --objects" does not open the
contents of blobs it prints. And when a commit graph is present, we skip
opening most commits entirely. The important thing will be to use this
flag in cases where it's safe to skip the check. For instance, when
serving a pack for a fetch, we know the client will fully index the
objects and do a connectivity check itself. There's little to be gained
from the server side re-hashing a blob itself. And indeed, most of the
time we don't! The revision machinery won't open up a blob reached by
traversal, but only one requested directly with a "want" line. So
applied properly, this new feature shouldn't make anything less safe in
practice.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:18:57 -07:00
SZEDER Gábor
dd834d75ca notes, remote: show unknown subcommands between `'
Update the "unknown subcommand" error message in 'git notes' and 'git
remote' to wrap the offending argument between `', to make it
consistent with the "unknown switch/option/subcommand" error messages
in parse-options.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:06:12 -07:00
SZEDER Gábor
1c7c25aef1 notes: simplify default operation mode arguments check
'git notes' has a default operation mode, but when invoked without a
subcommand it doesn't accept any arguments (although the 'list'
subcommand implementing the default operation mode does accept
arguments).  The condition checking this ended up a bit awkward, so
let's make it clearer.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:06:12 -07:00
SZEDER Gábor
45bec2ead2 test-parse-options.c: fix style of comparison with zero
The preferred style is '!argc' instead of 'argc == 0'.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:06:12 -07:00
SZEDER Gábor
6983f4e3b2 test-parse-options.c: don't use for loop initial declaration
We would like to eventually use for loop initial declarations in our
codebase, but we are not there yet.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:06:12 -07:00
SZEDER Gábor
9a22b4d907 t0040-parse-options: remove leftover debugging
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:06:12 -07:00
Jeff King
b27ccae34b rev-list: disable commit graph with --verify-objects
Since the point of --verify-objects is to actually load and checksum the
bytes of each object, optimizing out reads using the commit graph runs
contrary to our goal.

The most targeted way to implement this would be for the revision
traversal code to check revs->verify_objects and avoid using the commit
graph. But it's difficult to be sure we've hit all of the correct spots.
For instance, I started this patch by writing the first of the included
test cases, where the corrupted commit is directly on rev-list's command
line. And that is easy to fix by teaching get_reference() to check
revs->verify_objects before calling lookup_commit_in_graph().

But that doesn't cover the second test case: when we traverse to a
corrupted commit, we'd parse the parent in process_parents(). So we'd
need to check there, too. And it keeps going. In handle_commit() we
sometimes parses commits, too, though I couldn't figure out a way to
trigger it that did not already parse via get_reference() or tag
peeling. And try_to_simplify_commit() has its own parse call, and so on.

So it seems like the safest thing is to just disable the commit graph
for the whole process when we see the --verify-objects option. We can do
that either in builtin/rev-list.c, where we use the option, or in
revision.c, where we parse it. There are some subtleties:

  - putting it in rev-list.c is less surprising in some ways, because
    there we know we are just doing a single traversal. In a command
    which does multiple traversals in a single process, it's rather
    unexpected to globally disable the commit graph.

  - putting it in revision.c is less surprising in some ways, because
    the caller does not have to remember to disable the graph
    themselves. But this is already tricky! The verify_objects flag in
    rev_info doesn't do anything by itself. The caller has to provide an
    object callback which does the right thing.

  - for that reason, in practice nobody but rev-list uses this option in
    the first place. So the distinction is probably not important either
    way. Arguably it should just be an option of rev-list, and not the
    general revision machinery; right now you can run "git log
    --verify-objects", but it does not actually do anything useful.

  - checking for a parsed revs.verify_objects flag in rev-list.c is too
    late. By that time we've already passed the arguments to
    setup_revisions(), which will have parsed the commits using the
    graph.

So this commit disables the graph as soon as we see the option in
revision.c. That's a pretty broad hammer, but it does what we want, and
in practice nobody but rev-list is using this flag anyway.

The tests cover both the "tip" and "parent" cases. Obviously our hammer
hits them both in this case, but it's good to check both in case
somebody later tries the more focused approach.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 09:44:30 -07:00
Jeff King
d6045294a9 lookup_commit_in_graph(): use prepare_commit_graph() to check for graph
We exit early from lookup_commit_in_graph() if the commit_graph pointer
is NULL, under the assumption that we don't have a graph to look at. But
the graph pointer is lazy-loaded; if no other code happens to have
called prepare_commit_graph(), we'll incorrectly assume that one isn't
available at all.

This has a pretty small performance impact in practice, because the
fallback will generally be to call parse_object() instead. That ends up
in parse_commit_buffer(), which loads the graph data itself. So the
first commit we see won't use the graph, but subsequent ones will. Since
using the graph is just an optimization there's generally no
user-visible difference, but if you instrument rev-list like so:

  diff --git a/revision.c b/revision.c
  index ee702e498a..63c488ffb6 100644
  --- a/revision.c
  +++ b/revision.c
  @@ -381,6 +381,9 @@ static struct object *get_reference(struct rev_info *revs, const char *name,
           * parsing commit data from disk.
           */
          commit = lookup_commit_in_graph(revs->repo, oid);
  +       warning("%s %s in commit graph",
  +               commit ? "found" : "did not find",
  +               name);
          if (commit)
                  object = &commit->object;
          else

and run (in git.git):

  git commit-graph write --reachable
  git rev-list origin/master origin/next >/dev/null

you'll see that we fail to find the first one:

  warning: did not find origin/master in commit graph
  warning: found origin/next in commit graph

After this patch, you'll see that we find both:

  warning: found origin/master in commit graph
  warning: found origin/next in commit graph

Even though the performance implication is small here, there are two
important reasons to do this:

  - it's downright confusing if you are hunting a bug triggered by the
    use of the commit graph. It may or may not trigger depending on the
    number and ordering of tips you ask for.

  - prepare_commit_graph() has other policy logic, too. In particular,
    if we've loaded a commit graph and then disabled the graph via
    disable_commit_graph(), that should take precedence.

    I'm not sure if this can trigger bad behavior in practice. The only
    caller there is upload-pack's deepen_by_rev_list(), which should be
    avoiding the commit graph for its traversal tips, but probably
    wasn't before this patch. Whether you could come up with a case
    where that mattered is unclear. Still, this is obviously the right
    thing to be doing.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 09:44:28 -07:00
Junio C Hamano
79f2338b37 The eighteenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-05 18:33:41 -07:00
Junio C Hamano
27fb520ef2 Merge branch 'jk/test-crontab-fixes'
Test helper fix.

* jk/test-crontab-fixes:
  test-crontab: minor memory and error handling fixes
2022-09-05 18:33:41 -07:00
Junio C Hamano
fcbc8743ef Merge branch 'en/test-without-test-create-repo'
Test clean-up.

* en/test-without-test-create-repo:
  t64xx: convert 'test_create_repo' to 'git init'
2022-09-05 18:33:41 -07:00
Junio C Hamano
56785a3fad Merge branch 'bc/gc-crontab-fix'
FreeBSD portability fix for "git maintenance" that spawns "crontab"
to schedule tasks.

* bc/gc-crontab-fix:
  gc: use temporary file for editing crontab
2022-09-05 18:33:41 -07:00
Junio C Hamano
2d88021919 Merge branch 'es/t4301-sed-portability-fix'
Test clean-up.

* es/t4301-sed-portability-fix:
  t4301: emit blank line in more idiomatic fashion
  t4301: fix broken &&-chains and add missing loop termination
  t4301: account for behavior differences between sed implementations
2022-09-05 18:33:40 -07:00
Junio C Hamano
5784d201da Merge branch 'rs/test-mergesort'
Optimization of a test-helper command.

* rs/test-mergesort:
  test-mergesort: use mem_pool for sort input
  test-mergesort: read sort input all at once
2022-09-05 18:33:40 -07:00
Junio C Hamano
b5d2e9924f Merge branch 'rs/tempfile-cleanup-race-fix'
The clean-up of temporary files created via mks_tempfile_dt() was
racy and attempted to unlink() the leading directory when signals
are involved, which has been corrected.

* rs/tempfile-cleanup-race-fix:
  tempfile: avoid directory cleanup race
2022-09-05 18:33:40 -07:00
Junio C Hamano
3fe0121479 Merge branch 'ac/bitmap-lookup-table'
The pack bitmap file gained a bitmap-lookup table to speed up
locating the necessary bitmap for a given commit.

* ac/bitmap-lookup-table:
  pack-bitmap-write: drop unused pack_idx_entry parameters
  bitmap-lookup-table: add performance tests for lookup table
  pack-bitmap: prepare to read lookup table extension
  pack-bitmap-write: learn pack.writeBitmapLookupTable and add tests
  pack-bitmap-write.c: write lookup table extension
  bitmap: move `get commit positions` code to `bitmap_writer_finish`
  Documentation/technical: describe bitmap lookup table extension
2022-09-05 18:33:39 -07:00
Junio C Hamano
cf98b69053 Merge branch 'tb/midx-with-changing-preferred-pack-fix'
Multi-pack index got corrupted when preferred pack changed from one
pack to another in a certain way, which has been corrected.

* tb/midx-with-changing-preferred-pack-fix:
  midx.c: avoid adding preferred objects twice
  midx.c: include preferred pack correctly with existing MIDX
  midx.c: extract `midx_fanout_add_pack_fanout()`
  midx.c: extract `midx_fanout_add_midx_fanout()`
  midx.c: extract `struct midx_fanout`
  t/lib-bitmap.sh: avoid silencing stderr
  t5326: demonstrate potential bitmap corruption
2022-09-05 18:33:39 -07:00