Commit graph

376 commits

Author SHA1 Message Date
Junio C Hamano
1002f28a52 Merge branch 'eb/hash-transition'
Work to support a repository that work with both SHA-1 and SHA-256
hash algorithms has started.

* eb/hash-transition: (30 commits)
  t1016-compatObjectFormat: add tests to verify the conversion between objects
  t1006: test oid compatibility with cat-file
  t1006: rename sha1 to oid
  test-lib: compute the compatibility hash so tests may use it
  builtin/ls-tree: let the oid determine the output algorithm
  object-file: handle compat objects in check_object_signature
  tree-walk: init_tree_desc take an oid to get the hash algorithm
  builtin/cat-file: let the oid determine the output algorithm
  rev-parse: add an --output-object-format parameter
  repository: implement extensions.compatObjectFormat
  object-file: update object_info_extended to reencode objects
  object-file-convert: convert commits that embed signed tags
  object-file-convert: convert commit objects when writing
  object-file-convert: don't leak when converting tag objects
  object-file-convert: convert tag objects when writing
  object-file-convert: add a function to convert trees between algorithms
  object: factor out parse_mode out of fast-import and tree-walk into in object.h
  cache: add a function to read an OID of a specific algorithm
  tag: sign both hashes
  commit: export add_header_signature to support handling signatures on tags
  ...
2024-03-28 14:13:50 -07:00
Linus Arver
7cb26a1722 commit: ignore_non_trailer computes number of bytes to ignore
ignore_non_trailer() returns the _number of bytes_ that should be
ignored from the end of the log message. It does not by itself "ignore"
anything.

Rename this function to remove the leading "ignore" verb, to sound more
like a quantity than an action.

Signed-off-by: Linus Arver <linusa@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-20 14:25:12 -07:00
Eric W. Biederman
6bcc5fa20d commit: export add_header_signature to support handling signatures on tags
Rename add_commit_signature as add_header_signature, and expose it so
that it can be used for converting tags from one object format to
another.

Inspired-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-02 14:57:39 -07:00
Elijah Newren
d4a4f9291d commit.h: reduce unnecessary includes
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-24 12:47:33 -07:00
Junio C Hamano
e7dca80692 Merge branch 'ab/remove-implicit-use-of-the-repository' into en/header-split-cache-h
* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-04 08:25:52 -07:00
Ævar Arnfjörð Bjarmason
c7c33f50bd post-cocci: adjust comments for recent repo_* migration
In preceding commits we changed many calls to macros that were
providing a "the_repository" argument to invoke corresponding repo_*()
function instead. Let's follow-up and adjust references to those in
comments, which coccinelle didn't (and inherently can't) catch.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:46 -07:00
Ævar Arnfjörð Bjarmason
ecb5091fd4 cocci: apply the "commit.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"commit.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:45 -07:00
Elijah Newren
b6c09c03eb pretty.h: move has_non_ascii() declaration from commit.h
The function is defined in pretty.c, so this moves the declaration to
a more logical place.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:29 -08:00
Ævar Arnfjörð Bjarmason
d21878f073 add API: remove run_add_interactive() wrapper function
Now that the Perl "git-add--interactive" has gone away in the
preceding commit we don't need to pass along our desire for a mode as
a string, and can instead directly use the "enum add_p_mode", see
d2a233cb8b (built-in add -p: prepare for patch modes other than
"stage", 2019-12-21) for its introduction.

As a result of that the run_add_interactive() function would become a
trivial wrapper which would only run run_add_i() if a 0 (or now,
"NULL") "patch_mode" was provided. Let's instead remove it, and have
the one callsite that wanted the "NULL" case (interactive_add())
handle it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-06 15:03:34 -08:00
Phillip Wood
b8dbfd030c rebase: be stricter when reading state files containing oids
The state files for 'onto' and 'orig_head' should contain a full hex
oid, change the reading functions from get_oid() to get_oid_hex() to
reflect this. They should also name commits and not tags so add and use
a function that looks up a commit from an oid like
lookup_commit_reference() but without dereferencing tags.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-17 11:53:00 -07:00
Jonathan Tan
2a69ff09d5 shallow: reset commit grafts when shallow is reset
When reset_repository_shallow() is called, Git clears its cache of
shallow information, so that if shallow information is re-requested, Git
will read fresh data from disk instead of reusing its stale cached data.
However, the cache of commit grafts is not likewise cleared, even though
there are commit grafts created from shallow information.

This means that if on-disk shallow information were to be updated and
then a commit-graft-using codepath were run (for example, a revision
walk), Git would be using stale commit graft information. This can be
seen from the test in this patch, in which Git performs a revision walk
(to check for changed submodules) after a fetch with --update-shallow.

Therefore, clear the cache of commit grafts whenever
reset_repository_shallow() is called.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-17 17:44:38 -07:00
Ævar Arnfjörð Bjarmason
a8cc594333 hooks: fix an obscure TOCTOU "did we just run a hook?" race
Fix a Time-of-check to time-of-use (TOCTOU) race in code added in
680ee550d7 (commit: skip discarding the index if there is no
pre-commit hook, 2017-08-14).

This obscure race condition can occur if we e.g. ran the "pre-commit"
hook and it modified the index, but hook_exists() returns false later
on (e.g., because the hook itself went away, the directory became
unreadable, etc.). Then we won't call discard_cache() when we should
have.

The race condition itself probably doesn't matter, and users would
have been unlikely to run into it in practice. This problem has been
noted on-list when 680ee550d7 was discussed[1], but had not been
fixed.

This change is mainly intended to improve the readability of the code
involved, and to make reasoning about it more straightforward. It
wasn't as obvious what we were trying to do here, but by having an
"invoked_hook" it's clearer that e.g. our discard_cache() is happening
because of the earlier hook execution.

Let's also change this for the push-to-checkout hook. Now instead of
checking if the hook exists and either doing a push to checkout or a
push to deploy we'll always attempt a push to checkout. If the hook
doesn't exist we'll fall back on push to deploy. The same behavior as
before, without the TOCTOU race. See 0855331941 (receive-pack:
support push-to-checkout hook, 2014-12-01) for the introduction of the
previous behavior.

This leaves uses of hook_exists() in two places that matter. The
"reference-transaction" check in refs.c, see 6754159767 (refs:
implement reference transaction hook, 2020-06-19), and the
"prepare-commit-msg" hook, see 66618a50f9 (sequencer: run
'prepare-commit-msg' hook, 2018-01-24).

In both of those cases we're saving ourselves CPU time by not
preparing data for the hook that we'll then do nothing with if we
don't have the hook. So using this "invoked_hook" pattern doesn't make
sense in those cases.

The "reference-transaction" and "prepare-commit-msg" hook also aren't
racy. In those cases we'll skip the hook runs if we race with a new
hook being added, whereas in the TOCTOU races being fixed here we were
incorrectly skipping the required post-hook logic.

1. https://lore.kernel.org/git/20170810191613.kpmhzg4seyxy3cpq@sigill.intra.peff.net/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-07 13:00:53 -08:00
John Cai
cfc5cf428b receive-pack.c: consolidate find header logic
There are two functions that have very similar logic of finding a header
value. find_commit_header, and find_header. We can conslidate the logic
by introducing a new function find_header_mem, which is equivalent to
find_commit_header except it takes a len parameter that determines how
many bytes will be read. find_commit_header and find_header can then both
call find_header_mem.

This reduces duplicate logic, as the logic for finding header values
can now all live in one place.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-06 13:17:20 -08:00
Ævar Arnfjörð Bjarmason
ab628588f8 advice: move advice.graftFileDeprecated squashing to commit.[ch]
Move the squashing of the advice.graftFileDeprecated advice over to an
external variable in commit.[ch], allowing advice() to purely use the
new-style API of invoking advice() with an enum.

See 8821e90a09 (advice: don't pointlessly suggest
--convert-graft-file, 2018-11-27) for why quieting this advice was
needed. It's more straightforward to move this code to commit.[ch] and
use it builtin/replace.c, than to go through the indirection of
advice.[ch].

Because this was the last advice_config variable we can remove that
old facility from advice.c.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-25 12:07:52 -07:00
Junio C Hamano
89519f662c Merge branch 'cm/rebase-i-fixup-amend-reword'
"git commit --fixup=<commit>", which was to tweak the changes made
to the contents while keeping the original log message intact,
learned "--fixup=(amend|reword):<commit>", that can be used to
tweak both the message and the contents, and only the message,
respectively.

* cm/rebase-i-fixup-amend-reword:
  doc/git-commit: add documentation for fixup=[amend|reword] options
  t3437: use --fixup with options to create amend! commit
  t7500: add tests for --fixup=[amend|reword] options
  commit: add a reword suboption to --fixup
  commit: add amend suboption to --fixup to create amend! commit
  sequencer: export and rename subject_length()
2021-03-26 14:59:03 -07:00
Charvi Mendiratta
6e0e288779 sequencer: export and rename subject_length()
This function can be used in other parts of git. Let's move the
function to commit.c and also rename it to make the name of the
function more generic.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:29:35 -07:00
Junio C Hamano
15af6e6fee Merge branch 'bc/signed-objects-with-both-hashes'
Signed commits and tags now allow verification of objects, whose
two object names (one in SHA-1, the other in SHA-256) are both
signed.

* bc/signed-objects-with-both-hashes:
  gpg-interface: remove other signature headers before verifying
  ref-filter: hoist signature parsing
  commit: allow parsing arbitrary buffers with headers
  gpg-interface: improve interface for parsing tags
  commit: ignore additional signatures when parsing signed commits
  ref-filter: switch some uses of unsigned long to size_t
2021-02-22 16:12:42 -08:00
Junio C Hamano
5bd0b21bf7 Merge branch 'ds/commit-graph-genno-fix'
Fix incremental update of commit-graph file around corrected commit
date data.

* ds/commit-graph-genno-fix:
  commit-graph: prepare commit graph
  commit-graph: be extra careful about mixed generations
  commit-graph: compute generations separately
  commit-graph: validate layers for generation data
  commit-graph: always parse before commit_graph_data_at()
  commit-graph: use repo_parse_commit
2021-02-17 17:21:40 -08:00
Junio C Hamano
8b4701ae4f Merge branch 'ak/corrected-commit-date'
The commit-graph learned to use corrected commit dates instead of
the generation number to help topological revision traversal.

* ak/corrected-commit-date:
  doc: add corrected commit date info
  commit-reach: use corrected commit dates in paint_down_to_common()
  commit-graph: use generation v2 only if entire chain does
  commit-graph: implement generation data chunk
  commit-graph: implement corrected commit date
  commit-graph: return 64-bit generation number
  commit-graph: add a slab to store topological levels
  t6600-test-reach: generalize *_three_modes
  commit-graph: consolidate fill_commit_graph_info
  revision: parse parent in indegree_walk_step()
  commit-graph: fix regression when computing Bloom filters
2021-02-17 17:21:40 -08:00
brian m. carlson
937032e14a commit: allow parsing arbitrary buffers with headers
Currently only commits are signed with headers.  However, in the future,
we'll also sign tags with headers as well.  Let's refactor out a
function called parse_buffer_signed_by_header which does exactly that.
In addition, since we'll want to sign things other than commits this
way, let's call the function sign_with_header instead of do_sign_commit.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-10 23:35:42 -08:00
Derrick Stolee
c4cc083169 commit-graph: use repo_parse_commit
The write_commit_graph_context has a repository pointer, so use it.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-01 21:03:35 -08:00
Jeff King
98c431b6f9 commit_graft_pos(): take an oid instead of a bare hash
All of our callers have an object_id, and are just dereferencing the
hash field to pass to us. Let's take the actual object_id instead. We
still access the hash to pass to hash_pos, but it's a step in the right
direction.

This makes the callers slightly simpler, but also gets rid of the
untyped pointer, as well as the now-inaccurate name "sha1".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-28 11:21:07 -08:00
brian m. carlson
1fb5cf0da6 commit: ignore additional signatures when parsing signed commits
When we create a commit with multiple signatures, neither of these
signatures includes the other.  Consequently, when we produce the
payload which has been signed so we can verify the commit, we must strip
off any other signatures, or the payload will differ from what was
signed.  Do so, and in preparation for verifying with multiple
algorithms, pass the algorithm we want to verify into
parse_signed_commit.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 17:38:20 -08:00
Abhishek Kumar
e8b63005c4 commit-graph: implement generation data chunk
As discovered by Ævar, we cannot increment graph version to
distinguish between generation numbers v1 and v2 [1]. Thus, one of
pre-requistes before implementing generation number v2 was to
distinguish between graph versions in a backwards compatible manner.

We are going to introduce a new chunk called Generation DATa chunk (or
GDAT). GDAT will store corrected committer date offsets whereas CDAT
will still store topological level.

Old Git does not understand GDAT chunk and would ignore it, reading
topological levels from CDAT. New Git can parse GDAT and take advantage
of newer generation numbers, falling back to topological levels when
GDAT chunk is missing (as it would happen with a commit-graph written
by old Git).

We introduce a test environment variable 'GIT_TEST_COMMIT_GRAPH_NO_GDAT'
which forces commit-graph file to be written without generation data
chunk to emulate a commit-graph file written by old Git.

To minimize the space required to store corrrected commit date, Git
stores corrected commit date offsets into the commit-graph file, instea
of corrected commit dates. This saves us 4 bytes per commit, decreasing
the GDAT chunk size by half, but it's possible for the offset to
overflow the 4-bytes allocated for storage. As such overflows are and
should be exceedingly rare, we use the following overflow management
scheme:

We introduce a new commit-graph chunk, Generation Data OVerflow ('GDOV')
to store corrected commit dates for commits with offsets greater than
GENERATION_NUMBER_V2_OFFSET_MAX.

If the offset is greater than GENERATION_NUMBER_V2_OFFSET_MAX, we set
the MSB of the offset and the other bits store the position of corrected
commit date in GDOV chunk, similar to how Extra Edge List is maintained.

We test the overflow-related code with the following repo history:

           F - N - U
          /         \
U - N - U            N
         \          /
	  N - F - N

Where the commits denoted by U have committer date of zero seconds
since Unix epoch, the commits denoted by N have committer date of
1112354055 (default committer date for the test suite) seconds since
Unix epoch and the commits denoted by F have committer date of
(2 ^ 31 - 2) seconds since Unix epoch.

The largest offset observed is 2 ^ 31, just large enough to overflow.

[1]: https://lore.kernel.org/git/87a7gdspo4.fsf@evledraar.gmail.com/

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
d7f92784c6 commit-graph: return 64-bit generation number
In a preparatory step for introducing corrected commit dates, let's
return timestamp_t values from commit_graph_generation(), use
timestamp_t for local variables and define GENERATION_NUMBER_INFINITY
as (2 ^ 63 - 1) instead.

We rename GENERATION_NUMBER_MAX to GENERATION_NUMBER_V1_MAX to
represent the largest topological level we can store in the commit data
chunk.

With corrected commit dates implemented, we will have two such *_MAX
variables to denote the largest offset and largest topological level
that can be stored.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Junio C Hamano
45a177069f Merge branch 'en/merge-ort-recursive'
The ORT merge strategy learned to synthesize virtual ancestor tree
by recursively merging multiple merge bases together, just like the
recursive backend has done for years.

* en/merge-ort-recursive:
  merge-ort: implement merge_incore_recursive()
  merge-ort: make clear_internal_opts() aware of partial clearing
  merge-ort: copy a few small helper functions from merge-recursive.c
  commit: move reverse_commit_list() from merge-recursive
2021-01-06 23:33:44 -08:00
Elijah Newren
b0ca120554 commit: move reverse_commit_list() from merge-recursive
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-16 21:56:39 -08:00
Derrick Stolee
597b2c39af commit: implement commit_list_contains()
It can be helpful to check if a commit_list contains a commit. Use
pointer equality, assuming lookup_commit() was used.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-08 14:48:16 -08:00
Jeff King
e885a84f1b drop unused argc parameters
Many functions take an argv/argc pair, but never actually look at argc.
This makes it useless at best (we use the NULL sentinel in argv to find
the end of the array), and misleading at worst (what happens if the argc
count does not match the argv NULL?).

In each of these instances, the argv NULL does match the argc count, so
there are no bugs here. But let's tighten the interfaces to make it
harder to get wrong (and to reduce some -Wunused-parameter complaints).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 12:53:47 -07:00
Junio C Hamano
4831c23f75 Merge branch 'mf/submodule-summary-with-correct-repository'
"git diff/show" on a change that involves a submodule used to read
the information on commits in the submodule from a wrong repository
and gave a wrong information when the commit-graph is involved.

* mf/submodule-summary-with-correct-repository:
  submodule: use submodule repository when preparing summary
  revision: use repository from rev_info when parsing commits
2020-09-18 17:58:05 -07:00
Junio C Hamano
9c31b19dd0 Merge branch 'pw/rebase-i-more-options'
"git rebase -i" learns a bit more options.

* pw/rebase-i-more-options:
  t3436: do not run git-merge-recursive in dashed form
  rebase: add --reset-author-date
  rebase -i: support --ignore-date
  rebase -i: support --committer-date-is-author-date
  am: stop exporting GIT_COMMITTER_DATE
  rebase -i: add --ignore-whitespace flag
2020-09-03 12:37:01 -07:00
Phillip Wood
e8cbe2118a am: stop exporting GIT_COMMITTER_DATE
The implementation of --committer-date-is-author-date exports
GIT_COMMITTER_DATE to override the default committer date but does not
reset GIT_COMMITTER_DATE in the environment after creating the commit
so it is set in the environment of any hooks that get run. We're about
to add the same functionality to the sequencer and do not want to have
GIT_COMMITTER_DATE set when running hooks or exec commands so lets
update commit_tree_extended() to take an explicit committer so we
override the default date without setting GIT_COMMITTER_DATE in the
environment.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 11:58:37 -07:00
Michael Forney
ea3f7e598c revision: use repository from rev_info when parsing commits
This is needed when repo_init_revisions() is called with a repository
that is not the_repository to ensure appropriate repository is used
in repo_parse_commit_internal(). If the wrong repository is used,
a fatal error is the commit-graph machinery occurs:

  fatal: invalid commit position. commit-graph is likely corrupt

Since revision.c was the only user of the parse_commit_gently
compatibility define, remove it from commit.h.

Signed-off-by: Michael Forney <mforney@mforney.org>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-24 09:13:04 -07:00
Abhishek Kumar
c49c82aa4c commit: move members graph_pos, generation to a slab
We remove members `graph_pos` and `generation` from the struct commit.
The default assignments in init_commit_node() are no longer valid,
which is fine as the slab helpers return appropriate default values and
the assignments are removed.

We will replace existing use of commit->generation and commit->graph_pos
by commit_graph_data_slab helpers using
`contrib/coccinelle/commit.cocci'.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-17 14:37:30 -07:00
Taylor Blau
120ad2b0f1 shallow: extract a header file for shallow-related functions
There are many functions in commit.h that are more related to shallow
repositories than they are to any sort of generic commit machinery.
Likely this began when there were only a few shallow-related functions,
and commit.h seemed a reasonable enough place to put them.

But, now there are a good number of shallow-related functions, and
placing them all in 'commit.h' doesn't make sense.

This patch extracts a 'shallow.h', which takes all of the declarations
from 'commit.h' for functions which already exist in 'shallow.c'. We
will bring the remaining shallow-related functions defined in 'commit.c'
in a subsequent patch.

For now, move only the ones that already are implemented in 'shallow.c',
and update the necessary includes.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-30 14:19:13 -07:00
Taylor Blau
183df649ca commit: make 'commit_graft_pos' non-static
In the next patch, some functions will be moved from 'commit.c' to have
prototypes in a new 'shallow.h' and their implementations in
'shallow.c'.

Three functions in 'commit.c' use 'commit_graft_pos()' (they are
'register_commit_graft()', 'lookup_commit_graft()', and
'unregister_shallow()'). The first two of these will stay in 'commit.c',
but the latter will move to 'shallow.c', and thus needs
'commit_graft_pos' to be non-static.

Prepare for that by making 'commit_graft_pos' non-static so that it can
be called from both 'commit.c' and 'shallow.c'.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-30 14:18:41 -07:00
Taylor Blau
37b9dcabfc shallow.c: use '{commit,rollback}_shallow_file'
In bd0b42aed3 (fetch-pack: do not take shallow lock unnecessarily,
2019-01-10), the author noted that 'is_repository_shallow' produces
visible side-effect(s) by setting 'is_shallow' and 'shallow_stat'.

This is a problem for e.g., fetching with '--update-shallow' in a
shallow repository with 'fetch.writeCommitGraph' enabled, since the
update to '.git/shallow' will cause Git to think that the repository
isn't shallow when it is, thereby circumventing the commit-graph
compatibility check.

This causes problems in shallow repositories with at least shallow refs
that have at least one ancestor (since the client won't have those
objects, and therefore can't take the reachability closure over commits
when writing a commit-graph).

Address this by introducing thin wrappers over 'commit_lock_file' and
'rollback_lock_file' for use specifically when the lock is held over
'.git/shallow'. These wrappers (appropriately called
'commit_shallow_file' and 'rollback_shallow_file') call into their
respective functions in 'lockfile.h', but additionally reset validity
checks used by the shallow machinery.

Replace each instance of 'commit_lock_file' and 'rollback_lock_file'
with 'commit_shallow_file' and 'rollback_shallow_file' when the lock
being held is over the '.git/shallow' file.

As a result, 'prune_shallow' can now only be called once (since
'check_shallow_file_for_update' will die after calling
'reset_repository_shallow'). But, this is OK since we only call
'prune_shallow' at most once per process.

Helped-by: Jonathan Tan <jonathantanmy@google.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-24 13:56:39 -07:00
Hans Jerry Illikainen
54887b4689 gpg-interface: add minTrustLevel as a configuration option
Previously, signature verification for merge and pull operations checked
if the key had a trust-level of either TRUST_NEVER or TRUST_UNDEFINED in
verify_merge_signature().  If that was the case, the process die()d.

The other code paths that did signature verification relied entirely on
the return code from check_commit_signature().  And signatures made with
a good key, irregardless of its trust level, was considered valid by
check_commit_signature().

This difference in behavior might induce users to erroneously assume
that the trust level of a key in their keyring is always considered by
Git, even for operations where it is not (e.g. during a verify-commit or
verify-tag).

The way it worked was by gpg-interface.c storing the result from the
key/signature status *and* the lowest-two trust levels in the `result`
member of the signature_check structure (the last of these status lines
that were encountered got written to `result`).  These are documented in
GPG under the subsection `General status codes` and `Key related`,
respectively [1].

The GPG documentation says the following on the TRUST_ status codes [1]:

    """
    These are several similar status codes:

    - TRUST_UNDEFINED <error_token>
    - TRUST_NEVER     <error_token>
    - TRUST_MARGINAL  [0  [<validation_model>]]
    - TRUST_FULLY     [0  [<validation_model>]]
    - TRUST_ULTIMATE  [0  [<validation_model>]]

    For good signatures one of these status lines are emitted to
    indicate the validity of the key used to create the signature.
    The error token values are currently only emitted by gpgsm.
    """

My interpretation is that the trust level is conceptionally different
from the validity of the key and/or signature.  That seems to also have
been the assumption of the old code in check_signature() where a result
of 'G' (as in GOODSIG) and 'U' (as in TRUST_NEVER or TRUST_UNDEFINED)
were both considered a success.

The two cases where a result of 'U' had special meaning were in
verify_merge_signature() (where this caused git to die()) and in
format_commit_one() (where it affected the output of the %G? format
specifier).

I think it makes sense to refactor the processing of TRUST_ status lines
such that users can configure a minimum trust level that is enforced
globally, rather than have individual parts of git (e.g. merge) do it
themselves (except for a grace period with backward compatibility).

I also think it makes sense to not store the trust level in the same
struct member as the key/signature status.  While the presence of a
TRUST_ status code does imply that the signature is good (see the first
paragraph in the included snippet above), as far as I can tell, the
order of the status lines from GPG isn't well-defined; thus it would
seem plausible that the trust level could be overwritten with the
key/signature status if they were stored in the same member of the
signature_check structure.

This patch introduces a new configuration option: gpg.minTrustLevel.  It
consolidates trust-level verification to gpg-interface.c and adds a new
`trust_level` member to the signature_check structure.

Backward-compatibility is maintained by introducing a special case in
verify_merge_signature() such that if no user-configurable
gpg.minTrustLevel is set, then the old behavior of rejecting
TRUST_UNDEFINED and TRUST_NEVER is enforced.  If, on the other hand,
gpg.minTrustLevel is set, then that value overrides the old behavior.

Similarly, the %G? format specifier will continue show 'U' for
signatures made with a key that has a trust level of TRUST_UNDEFINED or
TRUST_NEVER, even though the 'U' character no longer exist in the
`result` member of the signature_check structure.  A new format
specifier, %GT, is also introduced for users that want to show all
possible trust levels for a signature.

Another approach would have been to simply drop the trust-level
requirement in verify_merge_signature().  This would also have made the
behavior consistent with other parts of git that perform signature
verification.  However, requiring a minimum trust level for signing keys
does seem to have a real-world use-case.  For example, the build system
used by the Qubes OS project currently parses the raw output from
verify-tag in order to assert a minimum trust level for keys used to
sign git tags [2].

[1] https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=blob;f=doc/doc/DETAILS;h=bd00006e933ac56719b1edd2478ecd79273eae72;hb=refs/heads/master
[2] 9674c1991d/scripts/verify-git-tag (L43)

Signed-off-by: Hans Jerry Illikainen <hji@dyntopia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 14:06:06 -08:00
Elijah Newren
15beaaa3d1 Fix spelling errors in code comments
Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-10 16:00:54 +09:00
Junio C Hamano
4aeeef3773 Merge branch 'dl/no-extern-in-func-decl'
Mechanically and systematically drop "extern" from function
declarlation.

* dl/no-extern-in-func-decl:
  *.[ch]: manually align parameter lists
  *.[ch]: remove extern from function declarations using sed
  *.[ch]: remove extern from function declarations using spatch
2019-05-13 23:50:32 +09:00
Junio C Hamano
0b179f3175 Merge branch 'nd/sha1-name-c-wo-the-repository'
Further code clean-up to allow the lowest level of name-to-object
mapping layer to work with a passed-in repository other than the
default one.

* nd/sha1-name-c-wo-the-repository: (34 commits)
  sha1-name.c: remove the_repo from get_oid_mb()
  sha1-name.c: remove the_repo from other get_oid_*
  sha1-name.c: remove the_repo from maybe_die_on_misspelt_object_name
  submodule-config.c: use repo_get_oid for reading .gitmodules
  sha1-name.c: add repo_get_oid()
  sha1-name.c: remove the_repo from get_oid_with_context_1()
  sha1-name.c: remove the_repo from resolve_relative_path()
  sha1-name.c: remove the_repo from diagnose_invalid_index_path()
  sha1-name.c: remove the_repo from handle_one_ref()
  sha1-name.c: remove the_repo from get_oid_1()
  sha1-name.c: remove the_repo from get_oid_basic()
  sha1-name.c: remove the_repo from get_describe_name()
  sha1-name.c: remove the_repo from get_oid_oneline()
  sha1-name.c: add repo_interpret_branch_name()
  sha1-name.c: remove the_repo from interpret_branch_mark()
  sha1-name.c: remove the_repo from interpret_nth_prior_checkout()
  sha1-name.c: remove the_repo from get_short_oid()
  sha1-name.c: add repo_for_each_abbrev()
  sha1-name.c: store and use repo in struct disambiguate_state
  sha1-name.c: add repo_find_unique_abbrev_r()
  ...
2019-05-09 00:37:25 +09:00
Denton Liu
ad6dad0996 *.[ch]: manually align parameter lists
In previous patches, extern was mechanically removed from function
declarations without care to formatting, causing parameter lists to be
misaligned. Manually format changed sections such that the parameter
lists should be realigned.

Viewing this patch with 'git diff -w' should produce no output.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05 15:20:10 +09:00
Denton Liu
b199d7147a *.[ch]: remove extern from function declarations using sed
There has been a push to remove extern from function declarations.
Finish the job by removing all instances of "extern" for function
declarations in headers using sed.

This was done by running the following on my system with sed 4.2.2:

    $ git ls-files \*.{c,h} |
        grep -v ^compat/ |
        xargs sed -i'' -e 's/^\(\s*\)extern \([^(]*([^*]\)/\1\2/'

Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.

Then, leftover instances of extern were found by running

    $ git grep -w -C3 extern \*.{c,h}

and manually checking the output. No other instances were found.

Note that the regex used specifically excludes function variables which
_should_ be left as extern.

Not the most elegant way to do it but it gets the job done.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05 15:20:08 +09:00
Denton Liu
554544276a *.[ch]: remove extern from function declarations using spatch
There has been a push to remove extern from function declarations.
Remove some instances of "extern" for function declarations which are
caught by Coccinelle. Note that Coccinelle has some difficulty with
processing functions with `__attribute__` or varargs so some `extern`
declarations are left behind to be dealt with in a future patch.

This was the Coccinelle patch used:

	@@
	type T;
	identifier f;
	@@
	- extern
	  T f(...);

and it was run with:

	$ git ls-files \*.{c,h} |
		grep -v ^compat/ |
		xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place

Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05 15:20:06 +09:00
Junio C Hamano
732ce7aaca Merge branch 'jt/fetch-no-update-shallow-in-proto-v2'
Fix for protocol v2 support in "git fetch-pack" of shallow clones.

* jt/fetch-no-update-shallow-in-proto-v2:
  fetch-pack: respect --no-update-shallow in v2
  fetch-pack: call prepare_shallow_info only if v0
2019-04-25 16:41:16 +09:00
Nguyễn Thái Ngọc Duy
301b8c7f40 commit.c: add repo_get_commit_tree()
Remove the implicit dependency on the_repository in this function.
It will be used in sha1-name.c functions when they are updated to take
any 'struct repository'. get_commit_tree() remains as a compat wrapper,
to be slowly replaced later.

Any access to "maybe_tree" field directly will result in _broken_ code
after running through commit.cocci because we can't know what is the
right repository to use.

the_repository would be correct most of the time. But we're relying less
and less on the_repository and that assumption may no longer be
true. The transformation now is more of a poor man replacement for a C++
compiler catching access to private fields.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-16 18:56:51 +09:00
Jonathan Tan
1e7d440b0a fetch-pack: call prepare_shallow_info only if v0
In fetch_pack(), be clearer that there is no shallow information before
the fetch when v2 is used - memset the struct shallow_info to 0 instead
of calling prepare_shallow_info().

This patch is in preparation for a future patch in which a v2 fetch
might call prepare_shallow_info() after shallow info has been retrieved
during the fetch, so I needed to ensure that prepare_shallow_info() is
not called before the fetch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01 15:35:54 +09:00
Ævar Arnfjörð Bjarmason
43d3561805 commit-graph write: don't die if the existing graph is corrupt
When the commit-graph is written we end up calling
parse_commit(). This will in turn invoke code that'll consult the
existing commit-graph about the commit, if the graph is corrupted we
die.

We thus get into a state where a failing "commit-graph verify" can't
be followed-up with a "commit-graph write" if core.commitGraph=true is
set, the graph either needs to be manually removed to proceed, or
core.commitGraph needs to be set to "false".

Change the "commit-graph write" codepath to use a new
parse_commit_no_graph() helper instead of parse_commit() to avoid
this. The latter will call repo_parse_commit_internal() with
use_commit_graph=1 as seen in 177722b344 ("commit: integrate commit
graph with commit parsing", 2018-04-10).

Not using the old graph at all slows down the writing of the new graph
by some small amount, but is a sensible way to prevent an error in the
existing commit-graph from spreading.

Just fixing the current issue would be likely to result in code that's
inadvertently broken in the future. New code might use the
commit-graph at a distance. To detect such cases introduce a
"GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD" setting used when we do our
corruption tests, and test that a "write/verify" combo works after
every one of our current test cases where we now detect commit-graph
corruption.

Some of the code changes here might be strictly unnecessary, e.g. I
was unable to find cases where the parse_commit() called from
write_graph_chunk_data() didn't exit early due to
"item->object.parsed" being true in
repo_parse_commit_internal() (before the use_commit_graph=1 has any
effect). But let's also convert those cases for good measure, we do
not have exhaustive tests for all possible types of commit-graph
corruption.

This might need to be re-visited if we learn to write the commit-graph
incrementally, but probably not. Hopefully we'll just start by finding
out what commits we have in total, then read the old graph(s) to see
what they cover, and finally write a new graph file with everything
that's missing. In that case the new graph writing code just needs to
continue to use e.g. a parse_commit() that doesn't consult the
existing commit-graphs.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01 12:14:50 +09:00
Junio C Hamano
b99a579f8e Merge branch 'sb/more-repo-in-api'
The in-core repository instances are passed through more codepaths.

* sb/more-repo-in-api: (23 commits)
  t/helper/test-repository: celebrate independence from the_repository
  path.h: make REPO_GIT_PATH_FUNC repository agnostic
  commit: prepare free_commit_buffer and release_commit_memory for any repo
  commit-graph: convert remaining functions to handle any repo
  submodule: don't add submodule as odb for push
  submodule: use submodule repos for object lookup
  pretty: prepare format_commit_message to handle arbitrary repositories
  commit: prepare logmsg_reencode to handle arbitrary repositories
  commit: prepare repo_unuse_commit_buffer to handle any repo
  commit: prepare get_commit_buffer to handle any repo
  commit-reach: prepare in_merge_bases[_many] to handle any repo
  commit-reach: prepare get_merge_bases to handle any repo
  commit-reach.c: allow get_merge_bases_many_0 to handle any repo
  commit-reach.c: allow remove_redundant to handle any repo
  commit-reach.c: allow merge_bases_many to handle any repo
  commit-reach.c: allow paint_down_to_common to handle any repo
  commit: allow parse_commit* to handle any repo
  object: parse_object to honor its repository argument
  object-store: prepare has_{sha1, object}_file to handle any repo
  object-store: prepare read_object_file to deal with any repo
  ...
2019-02-05 14:26:09 -08:00
Stefan Beller
6a7895fd8a commit: prepare free_commit_buffer and release_commit_memory for any repo
Pass the object pool to free_commit_buffer and release_commit_memory,
such that we can eliminate access to 'the_repository'.

Also remove the TODO in release_commit_memory, as commit->util was
removed in 9d2c97016f (commit.h: delete 'util' field in struct commit,
2018-05-19)

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-28 10:06:33 -08:00