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64361 Commits

Author SHA1 Message Date
René Scharfe 325006f2db oidset: make oidset_size() an inline function
oidset_size() just reads a single word from memory and returns it.
Avoid the function call overhead for this trivial operation by turning
it into an inline function.

While we're at it, declare its parameter const to allow it to be used
on read-only oidsets.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-12 16:14:32 -07:00
Ævar Arnfjörð Bjarmason e54e50201c INSTALL: reword and copy-edit the "libcurl" section
Make the "libcurl" section shorter and more to the point, this is
mostly based on suggestions from [1].

1. https://lore.kernel.org/git/YTtxcBdF2VQdWp5C@coredump.intra.peff.net/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-12 12:00:15 -07:00
Ævar Arnfjörð Bjarmason 5b952447cc INSTALL: don't mention the "curl" executable at all
In 1d53f90ed9 (The "curl" executable is no longer required,
2008-06-15) the wording for requiring curl(1) was changed to the
current "you might also want...".

Mentioning the "curl" executable at all is just confusing, someone
building git might want to use it to debug things, but they might also
just use wget(1) or some other http client. The "curl" executable has
the advantage that you might be able to e.g. reproduce a bug in git's
usage of libcurl with it, but anyone going to those extents is
unlikely to be aided by this note in INSTALL.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-12 12:00:14 -07:00
Elijah Newren c5ead19ea2 am: fix incorrect exit status on am fail to abort
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:51:15 -07:00
Elijah Newren 42b5e09d1e t4151: add a few am --abort tests
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:51:15 -07:00
Elijah Newren ea7dc012d2 git-am.txt: clarify --abort behavior
Both Johannes and I assumed (perhaps due to familiarity with rebase)
that am --abort would return the user to a clean state.  However, since
am, unlike rebase, is intended to be used within a dirty working tree,
--abort will only clean the files involved in the am operation.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:51:14 -07:00
Elijah Newren bee8691f19 stash: restore untracked files AFTER restoring tracked files
If a user deletes a file and places a directory of untracked files
there, then stashes all these changes, the untracked directory of files
cannot be restored until after the corresponding file in the way is
removed.  So, restore changes to tracked files before restoring
untracked files.

There is no counterpart problem to worry about with the user deleting an
untracked file and then add a tracked one in its place.  Git does not
track untracked files, and so will not know the untracked file was
deleted, and thus won't be able to stash the removal of that file.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:46:34 -07:00
Elijah Newren 3d40e3723b stash: avoid feeding directories to update-index
When a file is removed from the cache, but there is a file of the same
name present in the working directory, we would normally treat that file
in the working directory as untracked.  However, in the case of stash,
doing that would prevent a simple 'git stash push', because the untracked
file would be in the way of restoring the deleted file.

git stash, however, blindly assumes that whatever is in the working
directory for a deleted file is wanted and passes that path along to
update-index.  That causes problems when the working directory contains
a directory with the same name as the deleted file.  Add some code for
this special case that will avoid passing directory names to
update-index.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:46:34 -07:00
Elijah Newren 4dbf7f30b1 t3903: document a pair of directory/file bugs
There are three tests here, because the second bug is documented with
two tests: a file -> directory change and a directory -> file change.
The reason for the two tests is just to verify that both are indeed
broken but that both will be fixed by the same simple change (which will
be provided in a subsequent patch).

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:46:34 -07:00
Jeff King 1b421e7a5a docs/protocol-v2: point readers transport config discussion
We recently added tips for server admins to configure various transports
to support v2's GIT_PROTOCOL variable. While the protocol-v2 document is
pretty technical and not of interest to most admins, it may be a
starting point for them to figure out how to turn on v2. Let's put some
pointers from there to the other documentation.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:35:00 -07:00
Jeff King 2834a72d5e docs/git: discuss server-side config for GIT_PROTOCOL
The v2 protocol requires that the GIT_PROTOCOL environment variable gets
passed around, but we don't have any documentation describing how this
is supposed to work. In particular, we need to note what server admins
might need to configure to make things work.

The definition of the GIT_PROTOCOL variable is probably the best place
for this, since:

  - we deal with multiple transports (ssh, http, etc).
    Transport-specific documentation (like the git-http-backend bits
    added in the previous commit) are helpful for those transports, but
    this gives a broader overview. Plus we do not have a specific
    transport endpoint program for ssh, so this is a reasonable place to
    mention it.

  - the server side of the protocol involves multiple programs. For now,
    upload-pack is the only endpoint which uses GIT_PROTOCOL, but that
    will likely expand in the future. We're better off with a central
    discussion of what the server admin might need to do. However, for
    discoverability, this patch adds a pointer from upload-pack's
    documentation.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:34:59 -07:00
Jeff King 295d81b9e4 docs/http-backend: mention v2 protocol
Historically there was a little bit of configuration needed at the
webserver level in order to get the client's v2 protocol probes to Git.
But when we introduced the v2 protocol, we never documented these.

As of the previous commit, this should mostly work out of the box
without any explicit configuration. But it's worth documenting this to
make it clear how we expect it to work, especially in the face of
webservers which don't provide all headers over the CGI interface. Or
anybody who runs across this documentation but has an older version of
Git (or _used_ to have an older version, and wonders why they still have
a SetEnvIf line in their Apache config and whether it's still
necessary).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:34:59 -07:00
Jeff King ff6a37c99e http-backend: handle HTTP_GIT_PROTOCOL CGI variable
When a client requests the v2 protocol over HTTP, they set the
Git-Protocol header. Webservers will generally make that available to
our CGI as HTTP_GIT_PROTOCOL in the environment. However, that's not
sufficient for upload-pack, etc, to respect it; they look in
GIT_PROTOCOL (without the HTTP_ prefix).

Either the webserver or the CGI is responsible for relaying that HTTP
header into the GIT_PROTOCOL variable. Traditionally, our tests have
configured the webserver to do so, but that's a burden on the server
admin. We can make this work out of the box by having the http-backend
CGI copy the contents of HTTP_GIT_PROTOCOL to GIT_PROTOCOL.

There are no new tests here. By removing the SetEnvIf line from our
test Apache config, we're now relying on this behavior of http-backend
to trigger the v2 protocol there (and there are numerous tests that fail
if this doesn't work).

There is one subtlety here: we copy HTTP_GIT_PROTOCOL only if there is
no existing GIT_PROTOCOL variable. That leaves the webserver admin free
to override the client's decision if they choose. This is unlikely to be
useful in practice, but is more flexible. And indeed, it allows the
v2-to-v0 fallback test added in the previous commit to continue working.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:34:59 -07:00
Jeff King 26146980f1 t5551: test v2-to-v0 http protocol fallback
Since we use the v2 protocol by default, the connection of a v2 client
to a v2 server is well covered by the test suite. And with the
GIT_TEST_PROTOCOL_VERSION knob, we can easily test a v0 client
connecting to a v2-aware server (which will then just speak v0). But we
have no regular tests that a v2 client, when encountering a non-v2-aware
server, will correctly fall back to using v0.

In theory this is a job for the cross-version tests in t/interop, but:

  - they cover only git:// and file:// clones

  - they are not part of the usual test suite, so nobody ever runs them
    anyway

Since using v2 over http requires configuring the web server to pass
along the Git-Protocol header, we can easily create a situation where
the server does not respect the v2 probe, and the conversation falls
back to v0.

This works just fine. This new test is not about fixing any particular
bug, but just making sure that the system works (and continues to work)
as expected.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 15:34:58 -07:00
René Scharfe 6346f704a0 index-pack: use xopen in init_thread
Support an arbitrary file descriptor expression in the semantic patch
for replacing open+die_errno with xopen, not just an identifier, and
apply it.  This makes the error message at the single affected place
more consistent and reduces code duplication.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 14:22:50 -07:00
Junio C Hamano 8b7c11b866 The fifth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-10 11:47:10 -07:00
Junio C Hamano 96ac07f4a9 Merge branch 'ab/help-autocorrect-prompt'
The logic for auto-correction of misspelt subcommands learned to go
interactive when the help.autocorrect configuration variable is set
to 'prompt'.

* ab/help-autocorrect-prompt:
  help.c: help.autocorrect=prompt waits for user action
2021-09-10 11:46:33 -07:00
Junio C Hamano 613204b948 Merge branch 'cb/ci-build-pedantic'
CI update.

* cb/ci-build-pedantic:
  ci: run a pedantic build as part of the GitHub workflow
2021-09-10 11:46:32 -07:00
Junio C Hamano 9762646ee4 Merge branch 'gh/gitweb-branch-sort'
Tie-break branches that point at the same object in the list of
branches on GitWeb to show the one pointed at by HEAD early.

* gh/gitweb-branch-sort:
  gitweb: use HEAD as secondary sort key in git_get_heads_list()
2021-09-10 11:46:32 -07:00
Junio C Hamano 05665a0dff Merge branch 'rs/archive-use-object-id'
Code cleanup.

* rs/archive-use-object-id:
  archive: convert queue_directory to struct object_id
2021-09-10 11:46:31 -07:00
Junio C Hamano 09f66eb0e2 Merge branch 'rs/show-branch-simplify'
Code cleanup.

* rs/show-branch-simplify:
  show-branch: simplify rev_is_head()
2021-09-10 11:46:31 -07:00
Junio C Hamano bfe37f3dc5 Merge branch 'jk/log-warn-on-bogus-encoding'
Doc update plus improved error reporting.

* jk/log-warn-on-bogus-encoding:
  docs: use "character encoding" to refer to commit-object encoding
  logmsg_reencode(): warn when iconv() fails
2021-09-10 11:46:30 -07:00
Junio C Hamano a4b1a0ade4 Merge branch 'cb/remote-ndebug-fix'
Build fix.

* cb/remote-ndebug-fix:
  remote: avoid -Wunused-but-set-variable in gcc with -DNDEBUG
2021-09-10 11:46:30 -07:00
Junio C Hamano fd0d7036e0 Merge branch 'ab/retire-advice-config'
Code clean up to migrate callers from older advice_config[] based
API to newer advice_if_enabled() and advice_enabled() API.

* ab/retire-advice-config:
  advice: move advice.graftFileDeprecated squashing to commit.[ch]
  advice: remove use of global advice_add_embedded_repo
  advice: remove read uses of most global `advice_` variables
  advice: add enum variants for missing advice variables
2021-09-10 11:46:29 -07:00
Junio C Hamano 6d09fc54f6 Merge branch 'mk/clone-recurse-submodules'
After "git clone --recurse-submodules", all submodules are cloned
but they are not by default recursed into by other commands.  With
submodule.stickyRecursiveClone configuration set, submodule.recurse
configuration is set to true in a repository created by "clone"
with "--recurse-submodules" option.

* mk/clone-recurse-submodules:
  clone: set submodule.recurse=true if submodule.stickyRecursiveClone enabled
2021-09-10 11:46:29 -07:00
Junio C Hamano f0b567898b Merge branch 'ab/mailmap-leakfix'
Leakfix.

* ab/mailmap-leakfix:
  mailmap.c: fix a memory leak in free_mailap_{info,entry}()
2021-09-10 11:46:28 -07:00
Junio C Hamano 02d263277a Merge branch 'ab/gc-log-rephrase'
A pathname in an advice message has been made cut-and-paste ready.

* ab/gc-log-rephrase:
  gc: remove trailing dot from "gc.log" line
2021-09-10 11:46:28 -07:00
Junio C Hamano 6dbe1b4ee2 Merge branch 'uk/userdiff-php-enum'
Update the userdiff pattern for PHP.

* uk/userdiff-php-enum:
  userdiff: support enum keyword in PHP hunk header
2021-09-10 11:46:27 -07:00
Junio C Hamano febba8038d Merge branch 'tk/fast-export-anonymized-tag-fix'
The output from "git fast-export", when its anonymization feature
is in use, showed an annotated tag incorrectly.

* tk/fast-export-anonymized-tag-fix:
  fast-export: fix anonymized tag using original length
2021-09-10 11:46:27 -07:00
Junio C Hamano cd6a1fc8a2 Merge branch 'ba/object-info'
Leakfix.

* ba/object-info:
  protocol-caps.c: fix memory leak in send_info()
2021-09-10 11:46:26 -07:00
Junio C Hamano 1396a95ee0 Merge branch 'ab/commit-graph-usage'
Fixes on usage message from "git commit-graph".

* ab/commit-graph-usage:
  commit-graph: show "unexpected subcommand" error
  commit-graph: show usage on "commit-graph [write|verify] garbage"
  commit-graph: early exit to "usage" on !argc
  multi-pack-index: refactor "goto usage" pattern
  commit-graph: use parse_options_concat()
  commit-graph: remove redundant handling of -h
  commit-graph: define common usage with a macro
2021-09-10 11:46:25 -07:00
Junio C Hamano bd29bcf913 Merge branch 'mh/send-email-reset-in-reply-to'
Even when running "git send-email" without its own threaded
discussion support, a threading related header in one message is
carried over to the subsequent message to result in an unwanted
threading, which has been corrected.

* mh/send-email-reset-in-reply-to:
  send-email: avoid incorrect header propagation
2021-09-10 11:46:25 -07:00
Junio C Hamano 0538a2586e Merge branch 'rs/more-fspathcmp'
Code simplification.

* rs/more-fspathcmp:
  merge-recursive: use fspathcmp() in path_hashmap_cmp()
2021-09-10 11:46:24 -07:00
Junio C Hamano e4897d2bde Merge branch 'sg/set-ceiling-during-tests'
Buggy tests could damage repositories outside the throw-away test
area we created.  We now by default export GIT_CEILING_DIRECTORIES
to limit the damage from such a stray test.

* sg/set-ceiling-during-tests:
  test-lib: set GIT_CEILING_DIRECTORIES to protect the surrounding repository
2021-09-10 11:46:24 -07:00
Junio C Hamano 6f9e7cadf3 Merge branch 'jh/sparse-index-resize-fix'
The sparse-index support can corrupt the index structure by storing
a stale and/or uninitialized data, which has been corrected.

* jh/sparse-index-resize-fix:
  sparse-index: copy dir_hash in ensure_full_index()
2021-09-10 11:46:23 -07:00
Junio C Hamano b4ceeef962 Merge branch 'es/walken-tutorial-fix'
Typofix.

* es/walken-tutorial-fix:
  doc: fix syntax error and the format of printf
2021-09-10 11:46:23 -07:00
Junio C Hamano 9559de3b66 Merge branch 'tb/add-objects-in-unpacked-packs-simplify'
Code simplification with reduced memory usage.

* tb/add-objects-in-unpacked-packs-simplify:
  builtin/pack-objects.c: remove duplicate hash lookup
  builtin/pack-objects.c: simplify add_objects_in_unpacked_packs()
  object-store.h: teach for_each_packed_object to ignore kept packs
2021-09-10 11:46:21 -07:00
Junio C Hamano 87d4aed743 Merge branch 'ps/fetch-omit-formatting-under-quiet'
"git fetch --quiet" optimization to avoid useless computation of
info that will never be displayed.

* ps/fetch-omit-formatting-under-quiet:
  fetch: skip formatting updated refs with `--quiet`
2021-09-10 11:46:20 -07:00
Junio C Hamano 1ab13eb973 Merge branch 'ka/want-ref-in-namespace'
"git upload-pack" which runs on the other side of "git fetch"
forgot to take the ref namespaces into account when handling
want-ref requests.

* ka/want-ref-in-namespace:
  docs: clarify the interaction of transfer.hideRefs and namespaces
  upload-pack.c: treat want-ref relative to namespace
  t5730: introduce fetch command helper
2021-09-10 11:46:20 -07:00
Junio C Hamano 173368d73d Merge branch 'zh/cherry-pick-advice'
The advice message that "git cherry-pick" gives when it asks
conflicted replay of a commit to be resolved by the end user has
been updated.

* zh/cherry-pick-advice:
  cherry-pick: use better advice message
2021-09-10 11:46:19 -07:00
Junio C Hamano 6c083b7619 Merge branch 'js/advise-when-skipping-cherry-picked'
"git rebase" by default skips changes that are equivalent to
commits that are already in the history the branch is rebased onto;
give messages when this happens to let the users be aware of
skipped commits, and also teach them how to tell "rebase" to keep
duplicated changes.

* js/advise-when-skipping-cherry-picked:
  sequencer: advise if skipping cherry-picked commit
2021-09-10 11:46:19 -07:00
Ævar Arnfjörð Bjarmason 4bc1fd6e39 pack-objects: rename .idx files into place after .bitmap files
In preceding commits the race of renaming .idx files in place before
.rev files and other auxiliary files was fixed in pack-write.c's
finish_tmp_packfile(), builtin/repack.c's "struct exts", and
builtin/index-pack.c's final(). As noted in the change to pack-write.c
we left in place the issue of writing *.bitmap files after the *.idx,
let's fix that issue.

See 7cc8f97108 (pack-objects: implement bitmap writing, 2013-12-21)
for commentary at the time when *.bitmap was implemented about how
those files are written out, nothing in that commit contradicts what's
being done here.

Note that this commit and preceding ones only close any race condition
with *.idx files being written before their auxiliary files if we're
optimistic about our lack of fsync()-ing in this are not tripping us
over. See the thread at [1] for a rabbit hole of various discussions
about filesystem races in the face of doing and not doing fsync() (and
if doing fsync(), not doing it properly).

We may want to fsync the containing directory once after renaming the
*.idx file into place, but that is outside the scope of this series.

1. https://lore.kernel.org/git/8735qgkvv1.fsf@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Ævar Arnfjörð Bjarmason 2ec02dd5a8 pack-write: split up finish_tmp_packfile() function
Split up the finish_tmp_packfile() function and use the split-up version
in pack-objects.c in preparation for moving the step of renaming the
*.idx file later as part of a function change.

Since the only other caller of finish_tmp_packfile() was in
bulk-checkin.c, and it won't be needing a change to its *.idx renaming,
provide a thin wrapper for the old function as a static function in that
file. If other callers end up needing the simpler version it could be
moved back to "pack-write.c" and "pack.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Taylor Blau 522a5c2cf5 builtin/index-pack.c: move `.idx` files into place last
In a similar spirit as preceding patches to `git repack` and `git
pack-objects`, fix the identical problem in `git index-pack`.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Ævar Arnfjörð Bjarmason 8737dab346 index-pack: refactor renaming in final()
Refactor the renaming in final() into a helper function, this is
similar in spirit to a preceding refactoring of finish_tmp_packfile()
in pack-write.c.

Before e37d0b8730 (builtin/index-pack.c: write reverse indexes,
2021-01-25) it probably wasn't worth it to have this sort of helper,
due to the differing "else if" case for "pack" files v.s. "idx" files.

But since we've got "rev" as well now, let's do the renaming via a
helper, this is both a net decrease in lines, and improves the
readability, since we can easily see at a glance that the logic for
writing these three types of files is exactly the same, aside from the
obviously differing cases of "*final_name" being NULL, and
"make_read_only_if_same" being different.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Taylor Blau 4e58cedd94 builtin/repack.c: move `.idx` files into place last
In a similar spirit as the previous patch, fix the identical problem
from `git repack` (which invokes `pack-objects` with a temporary
location for output, and then moves the files into their final locations
itself).

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Taylor Blau 16a86907bc pack-write.c: rename `.idx` files after `*.rev`
We treat the presence of an `.idx` file as the indicator of whether or
not it's safe to use a packfile. But `finish_tmp_packfile()` (which is
responsible for writing the pack and moving the temporary versions of
all of its auxiliary files into place) is inconsistent about the write
order.

Specifically, it moves the `.rev` file into place after the `.idx`,
leaving open the possibility to open a pack which looks "ready" (because
the `.idx` file exists and is readable) but appears momentarily to not
have a `.rev` file. This causes Git to fall back to generating the
pack's reverse index in memory.

Though racy, this amounts to an unnecessary slow-down at worst, and
doesn't affect the correctness of the resulting reverse index.

Close this race by moving the .rev file into place before moving the
.idx file into place.

This still leaves the issue of `.idx` files being renamed into place
before the auxiliary `.bitmap` file is renamed when in pack-object.c's
write_pack_file() "write_bitmap_index" is true. That race will be
addressed in subsequent commits.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Ævar Arnfjörð Bjarmason 66833f0e70 pack-write: refactor renaming in finish_tmp_packfile()
Refactor the renaming in finish_tmp_packfile() into a helper function.
The callers are now expected to pass a "name_buffer" ending in
"pack-OID." instead of the previous "pack-", we then append "pack",
"idx" or "rev" to it.

By doing the strbuf_setlen() in rename_tmp_packfile() we reuse the
buffer and avoid the repeated allocations we'd get if that function had
its own temporary "struct strbuf".

This approach of reusing the buffer does make the last user in
pack-object.c's write_pack_file() slightly awkward, since we needlessly
do a strbuf_setlen() before calling strbuf_release() for consistency. In
subsequent changes we'll move that bitmap writing code around, so let's
not skip the strbuf_setlen() now.

The previous strbuf_reset() idiom originated with 5889271114
(finish_tmp_packfile():use strbuf for pathname construction,
2014-03-03), which in turn was a minimal adjustment of pre-strbuf code
added in 0e990530ae (finish_tmp_packfile(): a helper function,
2011-10-28).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Taylor Blau ae44b5a4f3 bulk-checkin.c: store checksum directly
finish_bulk_checkin() stores the checksum from finalize_hashfile() by
writing to the `hash` member of `struct object_id`, but that hash has
nothing to do with an object id (it's just a convenient location that
happens to be sized correctly).

Store the hash directly in an unsigned char array. This behaves the same
as writing to the `hash` member, but makes the intent clearer (and
avoids allocating an extra four bytes for the `algo` member of `struct
object_id`). It likewise prevents the possibility of a segfault when
reading `algo` (e.g., by calling `oid_to_hex()`) if it is uninitialized.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Jeff King e8f55568de t5562: use alarm() to interrupt timed child-wait
The t5562 script occasionally takes 60 extra seconds to complete due to
a race condition in the invoke-with-content-length.pl helper.

The way it's supposed to work is this:

  - we set up a SIGCLD handler

  - we kick off http-backend and write to it with a set content-length,
    but _don't_ close the pipe

  - we sleep for 60 seconds, assuming that SIGCLD from http-backend
    finishing will interrupt us

  - after the sleep finishes (whetherby 60 seconds or because it was
    interrupted by the signal), we check a flag to see if our SIGCLD
    handler was called. If not, then we complain.

This usually completes immediately, because the signal interrupts our
sleep. But very occasionally the child process dies _before_ we hit the
sleep, so we don't realize it. The test still completes successfully
(because our $exited flag is set), but it takes an extra 60 seconds.

There's no way to check the flag and sleep atomically. So the best we
can do with this approach is to sleep in smaller chunks (say, 1 second)
and check the flag incrementally. Then we waste a maximum of 1 second if
we lose the race. This was proposed in:

  https://lore.kernel.org/git/20190218205028.32486-1-max@max630.net/

and it does work. But we can do better.

Instead of blocking on sleep and waiting for the child signal to
interrupt us, we can block on the child exiting and set an alarm signal
to trigger the timeout.

This lets us exit the script immediately when the child behaves (with no
race possible), and wait a maximum of 60 seconds when it doesn't.

Note one small subtlety: perl is very willing to restart the waitpid()
call after the alarm is delivered, even if we've thrown an exception via
die. "perldoc -f alarm" claims you can get around this with an eval/die
combo (and even has some example code), but it doesn't seem to work for
me with waitpid(); instead, we continue waiting until the child exits.

So instead, we'll instruct the child process to exit in the alarm
handler itself. In the original code this was done by calling
close($out). That would continue to work, since our child is always
http-backend, which should exit when its stdin closes. But we can be
even more robust against a hung or confused child by sending a KILL
signal, which should terminate it immediately.

Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 17:45:43 -07:00