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
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
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>
We have a function which parses a buffer with a signature at the end,
parse_signature, and this function is used for signed tags. However,
we'll need to store values for multiple algorithms, and we'll do this by
using a header for the non-default algorithm.
Adjust the parse_signature interface to store the parsed data in two
strbufs and turn the existing function into parse_signed_buffer. The
latter is still used in places where we know we always have a signed
buffer, such as push certs.
Adjust all the callers to deal with this new interface.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we are looking up an oid in an array, we obviously don't need to
write to the array. Let's mark it as const in the function interfaces,
as well as in the local variables we use to derference the void pointer
(note a few cases use pointers-to-pointers, so we mark everything
const).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All of our callers are actually looking up an object_id, not a bare
hash. Likewise, the arrays they are looking in are actual arrays of
object_id (not just raw bytes of hashes, as we might find in a pack
.idx; those are handled by bsearch_hash()).
Using an object_id gives us more type safety, and makes the callers
slightly shorter. It also gets rid of the word "sha1" from several
access functions, though we could obviously also rename those with
s/sha1/hash/.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
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>
Retire more names with "sha1" in it.
* ma/sha1-is-a-hash:
hash-lookup: rename from sha1-lookup
sha1-lookup: rename `sha1_pos()` as `hash_pos()`
object-file.c: rename from sha1-file.c
object-name.c: rename from sha1-name.c
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
Change all remnants of "sha1" in hash-lookup.c and .h and rename them to
reflect that we're not just able to handle SHA-1 these days.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename this function to reflect that we're not just able to handle SHA-1
these days. There are a few instances of "sha1" left in sha1-lookup.[ch]
after this, but those will be addressed in the next commit.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Ted reported an old typo in the git-commit.txt and merge-options.txt.
Namely, the phrase "Signed-off-by line" was used without either a
definite nor indefinite article.
Upon examination, it seems that the documentation (including items in
Documentation/, but also option help strings) have been quite
inconsistent on usage when referring to `Signed-off-by`.
First, very few places used a definite or indefinite article with the
phrase "Signed-off-by line", but that was the initial typo that led
to this investigation. So, normalize using either an indefinite or
definite article consistently.
The original phrasing, in Commit 3f971fc425 (Documentation updates,
2005-08-14), is "Add Signed-off-by line". Commit 6f855371a5 (Add
--signoff, --check, and long option-names. 2005-12-09) switched to
using "Add `Signed-off-by:` line", but didn't normalize the former
commit to match. Later commits seem to have cut and pasted from one
or the other, which is likely how the usage became so inconsistent.
Junio stated on the git mailing list in
<xmqqy2k1dfoh.fsf@gitster.c.googlers.com> a preference to leave off
the colon. Thus, prefer `Signed-off-by` (with backticks) for the
documentation files and Signed-off-by (without backticks) for option
help strings.
Additionally, Junio argued that "trailer" is now the standard term to
refer to `Signed-off-by`, saying that "becomes plenty clear that we
are not talking about any random line in the log message". As such,
prefer "trailer" over "line" anywhere the former word fits.
However, leave alone those few places in documentation that use
Signed-off-by to refer to the process (rather than the specific
trailer), or in places where mail headers are generally discussed in
comparison with Signed-off-by.
Reported-by: "Theodore Y. Ts'o" <tytso@mit.edu>
Signed-off-by: Bradley M. Kuhn <bkuhn@sfconservancy.org>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git status" has trouble showing where it came from by interpreting
reflog entries that recordcertain events, e.g. "checkout @{u}", and
gives a hard/fatal error. Even though it inherently is impossible
to give a correct answer because the reflog entries lose some
information (e.g. "@{u}" does not record what branch the user was
on hence which branch 'the upstream' needs to be computed, and even
if the record were available, the relationship between branches may
have changed), at least hide the error to allow "status" show its
output.
* jt/interpret-branch-name-fallback:
wt-status: tolerate dangling marks
refs: move dwim_ref() to header file
sha1-name: replace unsigned int with option struct
"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
When a user checks out the upstream branch of HEAD, the upstream branch
not being a local branch, and then runs "git status", like this:
git clone $URL client
cd client
git checkout @{u}
git status
no status is printed, but instead an error message:
fatal: HEAD does not point to a branch
(This error message when running "git branch" persists even after
checking out other things - it only stops after checking out a branch.)
This is because "git status" reads the reflog when determining the "HEAD
detached" message, and thus attempts to DWIM "@{u}", but that doesn't
work because HEAD no longer points to a branch.
Therefore, when calculating the status of a worktree, tolerate dangling
marks. This is done by adding an additional parameter to
dwim_ref() and repo_dwim_ref().
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
The "argc" and "argv" names made sense when the struct was argv_array,
but now they're just confusing. Let's rename them to "nr" (which we use
for counts elsewhere) and "v" (which is rather terse, but reads well
when combined with typical variable names like "args.v").
Note that we have to update all of the callers immediately. Playing
tricks with the preprocessor is hard here, because we wouldn't want to
rewrite unrelated tokens.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).
This patch converts remaining files from the first half of the alphabet,
to keep the diff to a manageable size.
The conversion was done purely mechanically with:
git ls-files '*.c' '*.h' |
xargs perl -i -pe '
s/ARGV_ARRAY/STRVEC/g;
s/argv_array/strvec/g;
'
and then selectively staging files with "git add '[abcdefghjkl]*'".
We'll deal with any indentation/style fallouts separately.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When "fetch.writeCommitGraph" configuration is set in a shallow
repository and a fetch moves the shallow boundary, we wrote out
broken commit-graph files that do not match the reality, which has
been corrected.
* tb/fix-persistent-shallow:
commit.c: don't persist substituted parents when unshallowing
Since 37b9dcabfc (shallow.c: use '{commit,rollback}_shallow_file',
2020-04-22), Git knows how to reset stat-validity checks for the
$GIT_DIR/shallow file, allowing it to change between a shallow and
non-shallow state in the same process (e.g., in the case of 'git fetch
--unshallow').
However, when $GIT_DIR/shallow changes, Git does not alter or remove any
grafts (nor substituted parents) in memory.
This comes up in a "git fetch --unshallow" with fetch.writeCommitGraph
set to true. Ordinarily in a shallow repository (and before 37b9dcabfc,
even in this case), commit_graph_compatible() would return false,
indicating that the repository should not be used to write a
commit-graphs (since commit-graph files cannot represent a shallow
history). But since 37b9dcabfc, in an --unshallow operation that check
succeeds.
Thus even though the repository isn't shallow any longer (that is, we
have all of the objects), the in-core representation of those objects
still has munged parents at the shallow boundaries. When the
commit-graph write proceeds, we use the incorrect parentage, producing
wrong results.
There are two ways for a user to work around this: either (1) set
'fetch.writeCommitGraph' to 'false', or (2) drop the commit-graph after
unshallowing.
One way to fix this would be to reset the parsed object pool entirely
(flushing the cache and thus preventing subsequent reads from modifying
their parents) after unshallowing. That would produce a problem when
callers have a now-stale reference to the old pool, and so this patch
implements a different approach. Instead, attach a new bit to the pool,
'substituted_parent', which indicates if the repository *ever* stored a
commit which had its parents modified (i.e., the shallow boundary
prior to unshallowing).
This bit needs to be sticky because all reads subsequent to modifying a
commit's parents are unreliable when unshallowing. Modify the check in
'commit_graph_compatible' to take this bit into account, and correctly
avoid generating commit-graphs in this case, thus solving the bug.
Helped-by: Derrick Stolee <dstolee@microsoft.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Reported-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In an earlier patch, multiple struct acccesses to `graph_pos` and
`generation` were auto-converted to multiple method calls.
Since the values are fixed and commit-slab access costly, we would be
better off with storing the values as a local variable and reusing it.
Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
14ba97f8 (alloc: allow arbitrary repositories for alloc functions,
2018-05-15) introduced parsed_object_pool->commit_count to keep count of
commits per repository and was used to assign commit->index.
However, commit-slab code requires commit->index values to be unique
and a global count would be correct, rather than a per-repo count.
Let's introduce a static counter variable, `parsed_commits_count` to
keep track of parsed commits so far.
As commit_count has no use anymore, let's also drop it from the struct.
Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
The "--fork-point" mode of "git rebase" regressed when the command
was rewritten in C back in 2.20 era, which has been corrected.
* at/rebase-fork-point-regression-fix:
rebase: --fork-point regression fix
The transition plan anticipates that we will allow signatures using
multiple algorithms in a single commit. In order to do so, we need to
use a different header per algorithm so that it will be obvious over
which data to compute the signature.
The transition plan specifies that we should use "gpgsig-sha256", so
wire up the commit code such that it can write and parse the current
algorithm, and it can remove the headers for any algorithm when creating
a new commit. Add tests to ensure that we write using the right header
and that git fsck doesn't reject these commits.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rebase --fork-point master" used to work OK, as it internally
called "git merge-base --fork-point" that knew how to handle short
refname and dwim it to the full refname before calling the
underlying get_fork_point() function.
This is no longer true after the command was rewritten in C, as its
internall call made directly to get_fork_point() does not dwim a
short ref.
Move the "dwim the refname argument to the full refname" logic that
is used in "git merge-base" to the underlying get_fork_point()
function, so that the other caller of the function in the
implementation of "git rebase" behaves the same way to fix this
regression.
Signed-off-by: Alex Torok <alext9@gmail.com>
[jc: revamped the fix and used Alex's tests]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a function for inserting a C string into a strbuf. Use it
throughout the source to get rid of magic string length constants and
explicit strlen() calls.
Like strbuf_addstr(), implement it as an inline function to avoid the
implicit strlen() calls to cause runtime overhead.
Helped-by: Taylor Blau <me@ttaylorr.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Crufty code and logic accumulated over time around the object
parsing and low-level object access used in "git fsck" have been
cleaned up.
* jk/cleanup-object-parsing-and-fsck: (23 commits)
fsck: accept an oid instead of a "struct tree" for fsck_tree()
fsck: accept an oid instead of a "struct commit" for fsck_commit()
fsck: accept an oid instead of a "struct tag" for fsck_tag()
fsck: rename vague "oid" local variables
fsck: don't require an object struct in verify_headers()
fsck: don't require an object struct for fsck_ident()
fsck: drop blob struct from fsck_finish()
fsck: accept an oid instead of a "struct blob" for fsck_blob()
fsck: don't require an object struct for report()
fsck: only require an oid for skiplist functions
fsck: only provide oid/type in fsck_error callback
fsck: don't require object structs for display functions
fsck: use oids rather than objects for object_name API
fsck_describe_object(): build on our get_object_name() primitive
fsck: unify object-name code
fsck: require an actual buffer for non-blobs
fsck: stop checking tag->tagged
fsck: stop checking commit->parent counts
fsck: stop checking commit->tree value
commit, tag: don't set parsed bit for parse failures
...
"rebase -i" ceased to run post-commit hook by mistake in an earlier
update, which has been corrected.
* pw/post-commit-from-sequencer:
sequencer: run post-commit hook
move run_commit_hook() to libgit and use it there
sequencer.h fix placement of #endif
t3404: remove uneeded calls to set_fake_editor
t3404: set $EDITOR in subshell
t3404: remove unnecessary subshell
If we can't parse a commit, then parse_commit() will return an error
code. But it _also_ sets the "parsed" flag, which tells us not to bother
trying to re-parse the object. That means that subsequent parses have no
idea that the information in the struct may be bogus. I.e., doing this:
parse_commit(commit);
...
if (parse_commit(commit) < 0)
die("commit is broken");
will never trigger the die(). The second parse_commit() will see the
"parsed" flag and quietly return success.
There are two obvious ways to fix this:
1. Stop setting "parsed" until we've successfully parsed.
2. Keep a second "corrupt" flag to indicate that we saw an error (and
when the parsed flag is set, return 0/-1 depending on the corrupt
flag).
This patch does option 1. The obvious downside versus option 2 is that
we might continually re-parse a broken object. But in practice,
corruption like this is rare, and we typically die() or return an error
in the caller. So it's OK not to worry about optimizing for corruption.
And it's much simpler: we don't need to use an extra bit in the object
struct, and callers which check the "parsed" flag don't need to learn
about the corrupt bit, too.
There's no new test here, because this case is already covered in t5318.
Note that we do need to update the expected message there, because we
now detect the problem in the return from "parse_commit()", and not with
a separate check for a NULL tree. In fact, we can now ditch that
explicit tree check entirely, as we're covered robustly by this change
(and the previous recent change to treat a NULL tree as a parse error).
We'll also give tags the same treatment. I don't know offhand of any
cases where the problem can be triggered (it implies somebody ignoring a
parse error earlier in the process), but consistently returning an error
should cause the least surprise.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If parsing a commit yields a valid tree oid, but we've seen that same
oid as a non-tree in the same process, the resulting commit struct will
end up with a NULL tree pointer, but not otherwise report a parsing
failure.
That's perhaps convenient for callers which want to operate on even
partially corrupt commits (e.g., by still looking at the parents). But
it leaves a potential trap for most callers, who now have to manually
check for a NULL tree. Most do not, and it's likely that there are
possible segfaults lurking. I say "possible" because there are many
candidates, and I don't think it's worth following through on
reproducing them when we can just fix them all in one spot. And
certainly we _have_ seen real-world cases, such as the one fixed by
806278dead (commit-graph.c: handle corrupt/missing trees, 2019-09-05).
Note that we can't quite drop the check in the caller added by that
commit yet, as there's some subtlety with repeated parsings (which will
be addressed in a future commit).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While parsing the parents of a commit, if we are able to parse an actual
oid but lookup_commit() fails on it (because we previously saw it in
this process as a different object type), we silently omit the parent
and do not report any error to the caller.
The caller has no way of knowing this happened, because even an empty
parent list is a valid parse result. As a result, it's possible to fool
our "rev-list" connectivity check into accepting a corrupted set of
objects.
There's a test for this case already in t6102, but unfortunately it has
a slight error. It creates a broken commit with a parent line pointing
to a blob, and then checks that rev-list notices the problem in two
cases:
1. the "lone" case: we traverse the broken commit by itself (here we
try to actually load the blob from disk and find out that it's not
a commit)
2. the "seen" case: we parse the blob earlier in the process, and then
when calling lookup_commit() we realize immediately that it's not a
commit
The "seen" variant for this test mistakenly parsed another commit
instead of the blob, meaning that we were actually just testing the
"lone" case again. Changing that reveals the breakage (and shows that
this fixes it).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function was declared in commit.h but was implemented in
builtin/commit.c so was not part of libgit. Move it to libgit so we can
use it in the sequencer. This simplifies the implementation of
run_prepare_commit_msg_hook() and will be used in the next commit.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code to parse and use the commit-graph file has been made more
robust against corrupted input.
* tb/commit-graph-harden:
commit-graph.c: handle corrupt/missing trees
commit-graph.c: handle commit parsing errors
t/t5318: introduce failing 'git commit-graph write' tests
Apply similar treatment as in the previous commit to handle an unchecked
call to 'get_commit_tree_oid()'. Previously, a NULL return value from
this function would be immediately dereferenced with '->hash', and then
cause a segfault.
Before dereferencing to access the 'hash' member, check the return value
of 'get_commit_tree_oid()' to make sure that it is not NULL.
To make this check correct, a related change is also needed in
'commit.c', which is to check the return value of 'get_commit_tree'
before taking its address. If 'get_commit_tree' returns NULL, we
encounter an undefined behavior when taking the address of the return
value of 'get_commit_tree' and then taking '->object.oid'. (On my system,
this is memory address 0x8, which is obviously wrong).
Fix this by making sure that 'get_commit_tree' returns something
non-NULL before digging through a structure that is not there, thus
preventing a segfault down the line in the commit graph code.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The index field in the commit object is used to find the buffer
corresponding to that commit in the buffer_slab. Resetting it first
means free_commit_buffer is not going to free the right buffer.
Signed-off-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit-graph file is now part of the "files that the runtime
may keep open file descriptors on, all of which would need to be
closed when done with the object store", and the file descriptor to
an existing commit-graph file now is closed before "gc" finalizes a
new instance to replace it.
* ds/close-object-store:
packfile: rename close_all_packs to close_object_store
packfile: close commit-graph in close_all_packs
commit-graph: use raw_object_store when closing
commit-graph: extract write_commit_graph_file()
commit-graph: extract copy_oids_to_commits()
commit-graph: extract count_distinct_commits()
commit-graph: extract fill_oids_from_all_packs()
commit-graph: extract fill_oids_from_commit_hex()
commit-graph: extract fill_oids_from_packs()
commit-graph: create write_commit_graph_context
commit-graph: remove Future Work section
commit-graph: collapse parameters into flags
commit-graph: return with errors during write
commit-graph: fix the_repository reference
Code clean-up to remove hardcoded SHA-1 hash from many places.
* jk/oidhash:
hashmap: convert sha1hash() to oidhash()
hash.h: move object_id definition from cache.h
khash: rename oid helper functions
khash: drop sha1-specific map types
pack-bitmap: convert khash_sha1 maps into kh_oid_map
delta-islands: convert island_marks khash to use oids
khash: rename kh_oid_t to kh_oid_set
khash: drop broken oid_map typedef
object: convert create_object() to use object_id
object: convert internal hash_obj() to object_id
object: convert lookup_object() to use object_id
object: convert lookup_unknown_object() to use object_id
pack-objects: convert locate_object_entry_hash() to object_id
pack-objects: convert packlist_find() to use object_id
pack-bitmap-write: convert some helpers to use object_id
upload-pack: rename a "sha1" variable to "oid"
describe: fix accidental oid/hash type-punning
There are no callers left of create_object() that aren't just passing us
the "hash" member of a "struct object_id". Let's take the whole struct,
which gets us closer to removing all raw sha1 variables.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
