builtin/clone: create the refdb with the correct object format
We're currently creating the reference database with a potentially
incorrect object format when the remote repository's object format is
different from the local default object format. This works just fine for
now because the files backend never records the object format anywhere.
But this logic will fail with any new reference backend that encodes
this information in some form either on-disk or in-memory.
The preceding commits have reshuffled code in git-clone(1) so that there
is no code path that will access the reference database before we have
detected the remote's object format. With these refactorings we can now
defer initialization of the reference database until after we have
learned the remote's object format and thus initialize it with the
correct format from the get-go.
These refactorings are required to make git-clone(1) work with the
upcoming reftable backend when cloning repositories with the SHA256
object format.
This change breaks a test in "t5550-http-fetch-dumb.sh" when cloning an
empty repository with `GIT_TEST_DEFAULT_HASH=sha256`. The test expects
the resulting hash format of the empty cloned repository to match the
default hash, but now we always end up with a sha1 repository. The
problem is that for dumb HTTP fetches, we have no easy way to figure out
the remote's hash function except for deriving it based on the hash
length of refs in `info/refs`. But as the remote repository is empty we
cannot rely on this detection mechanism.
Before the change in this commit we already initialized the repository
with the default hash function and then left it as-is. With this patch
we always use the hash function detected via the remote, where we fall
back to "sha1" in case we cannot detect it.
Neither the old nor the new behaviour are correct as we second-guess the
remote hash function in both cases. But given that this is a rather
unlikely edge case (we use the dumb HTTP protocol, the remote repository
uses SHA256 and the remote repository is empty), let's simply adapt the
test to assert the new behaviour. If we want to properly address this
edge case in the future we will have to extend the dumb HTTP protocol so
that we can properly detect the hash function for empty repositories.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/clone: skip reading HEAD when retrieving remote
After we have set up the remote configuration in git-clone(1) we'll call
`remote_get()` to read the remote from the on-disk configuration. But
next to reading the on-disk configuration, `remote_get()` will also
cause us to try and read the repository's HEAD reference so that we can
figure out the current branch. Besides being pointless in git-clone(1)
because we're operating in an empty repository anyway, this will also
break once we move creation of the reference database to a later point
in time.
Refactor the code to introduce a new `remote_get_early()` function that
will skip reading the HEAD reference to address this issue.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When asked to do a sparse checkout, then git-clone(1) will spawn
`git sparse-checkout set` to set up the configuration accordingly. This
requires a proper Git repository or otherwise the command will fail. But
as we are about to move creation of the reference database to a later
point, this prerequisite will not hold anymore.
Move the logic to a later point in time where we know to have created
the reference database already.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/clone: fix bundle URIs with mismatching object formats
We create the reference database in git-clone(1) quite early before
connecting to the remote repository. Given that we do not yet know about
the object format that the remote repository uses at that point in time
the consequence is that the refdb may be initialized with the wrong
object format.
This is not a problem in the context of the files backend as we do not
encode the object format anywhere, and furthermore the only reference
that we write between initializing the refdb and learning about the
object format is the "HEAD" symref. It will become a problem though once
we land the reftable backend, which indeed does require to know about
the proper object format at the time of creation. We thus need to
rearrange the logic in git-clone(1) so that we only initialize the refdb
once we have learned about the actual object format.
As a first step, move listing of remote references to happen earlier,
which also allow us to set up the hash algorithm of the repository
earlier now. While we aim to execute this logic as late as possible
until after most of the setup has happened already, detection of the
object format and thus later the setup of the reference database must
happen before any other logic that may spawn Git commands or otherwise
these Git commands may not recognize the repository as such.
The first Git step where we expect the repository to be fully initalized
is when we fetch bundles via bundle URIs. Funny enough, the comments
there also state that "the_repository must match the cloned repo", which
is indeed not necessarily the case for the hash algorithm right now. So
in practice it is the right thing to detect the remote's object format
before downloading bundle URIs anyway, and not doing so causes clones
with bundle URIs to fail when the local default object format does not
match the remote repository's format.
Unfortunately though, this creates a new issue: downloading bundles may
take a long time, so if we list refs beforehand they might've grown
stale meanwhile. It is not clear how to solve this issue except for a
second reference listing though after we have downloaded the bundles,
which may be an expensive thing to do.
Arguably though, it's preferable to have a staleness issue compared to
being unable to clone a repository altogether.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-curl: rediscover repository when fetching refs
The reftable format encodes the hash function used by the repository
inside of its tables. The reftable backend thus needs to be initialized
with the correct hash function right from the start, or otherwise we may
end up writing tables with the wrong hash function. But git-clone(1)
initializes the reference database before learning about the hash
function used by the remote repository, which has never been a problem
with the reffiles backend.
To fix this, we'll have to change git-clone(1) to be more careful and
only create the reference backend once it learned about the remote hash
function. This creates a problem for git-remote-curl(1), which will then
be spawned at a time where the repository is not yet fully-initialized.
Consequentially, git-remote-curl(1) will fail to detect the repository,
which eventually causes it to error out once it is asked to fetch remote
objects.
We can address this issue by trying to re-discover the Git repository in
case none was detected at startup time. With this change, the clone will
look as following:
1. git-clone(1) sets up the initial repository, excluding the
reference database.
2. git-clone(1) spawns git-remote-curl(1), which will be unable to
detect the repository due to a missing "HEAD".
3. git-clone(1) asks git-remote-curl(1) to list remote references.
This works just fine as this step does not require a local
repository
4. git-clone(1) creates the reference database as it has now learned
about the hash function.
5. git-clone(1) asks git-remote-curl(1) to fetch the remote packfile.
The latter notices that it doesn't have a repository available, but
it now knows to try and re-discover it.
If the re-discovery succeeds in the last step we can continue with the
clone.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow callers to skip creation of the reference database via a new flag
`INIT_DB_SKIP_REFDB`, which is required for git-clone(1) so that we can
create it at a later point once the object format has been discovered
from the remote repository.
Note that we also uplift the call to `create_reference_database()` into
`init_db()`, which makes it easier to handle the new flag for us. This
changes the order in which we do initialization so that we now set up
the Git configuration before we create the reference database. In
practice this move should not result in any change in behaviour.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're about to let callers skip creation of the reference database when
calling `init_db()`. Extract the logic into a standalone function so
that it becomes easier to do this refactoring.
While at it, expand the comment that explains why we always create the
"refs/" directory.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye [Mon, 13 Nov 2023 23:17:51 +0000 (23:17 +0000)]
glossary: add definitions for dereference & peel
Add 'gitglossary' definitions for "dereference" (as it used for both symrefs
and objects) and "peel". These terms are used in options and documentation
throughout Git, but they are not clearly defined anywhere and the behavior
they refer to depends heavily on context. Provide explicit definitions to
clarify existing documentation to users and help contributors to use the
most appropriate terminology possible in their additions to Git.
Update other definitions in the glossary that use the term "dereference" to
link to 'def_dereference'.
Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Wed, 8 Nov 2023 06:04:41 +0000 (15:04 +0900)]
Merge branch 'ps/leakfixes'
Leakfix.
* ps/leakfixes:
setup: fix leaking repository format
setup: refactor `upgrade_repository_format()` to have common exit
shallow: fix memory leak when registering shallow roots
test-bloom: stop setting up Git directory twice
Junio C Hamano [Wed, 8 Nov 2023 02:04:01 +0000 (11:04 +0900)]
Merge branch 'kn/rev-list-missing-fix'
"git rev-list --missing" did not work for missing commit objects,
which has been corrected.
* kn/rev-list-missing-fix:
rev-list: add commit object support in `--missing` option
rev-list: move `show_commit()` to the bottom
revision: rename bit to `do_not_die_on_missing_objects`
Junio C Hamano [Wed, 8 Nov 2023 02:03:59 +0000 (11:03 +0900)]
Merge branch 'ps/show-ref'
Teach "git show-ref" a mode to check the existence of a ref.
* ps/show-ref:
t: use git-show-ref(1) to check for ref existence
builtin/show-ref: add new mode to check for reference existence
builtin/show-ref: explicitly spell out different modes in synopsis
builtin/show-ref: ensure mutual exclusiveness of subcommands
builtin/show-ref: refactor options for patterns subcommand
builtin/show-ref: stop using global vars for `show_one()`
builtin/show-ref: stop using global variable to count matches
builtin/show-ref: refactor `--exclude-existing` options
builtin/show-ref: fix dead code when passing patterns
builtin/show-ref: fix leaking string buffer
builtin/show-ref: split up different subcommands
builtin/show-ref: convert pattern to a local variable
The codepath to traverse the commit-graph learned to notice that a
commit is missing (e.g., corrupt repository lost an object), even
though it knows something about the commit (like its parents) from
what is in commit-graph.
* ps/do-not-trust-commit-graph-blindly-for-existence:
commit: detect commits that exist in commit-graph but not in the ODB
commit-graph: introduce envvar to disable commit existence checks
Taylor Blau [Mon, 6 Nov 2023 22:56:33 +0000 (17:56 -0500)]
pack-bitmap: drop --unpacked non-commit objects from results
When performing revision queries with `--objects` and
`--use-bitmap-index`, the output may incorrectly contain objects which
are packed, even when the `--unpacked` option is given. This affects
traversals, but also other querying operations, like `--count`,
`--disk-usage`, etc.
Like in the previous commit, the fix is to exclude those objects from
the result set before they are shown to the user (or, in this case,
before the bitmap containing the result of the traversal is enumerated
and its objects listed).
This is performed by a new function in pack-bitmap.c, called
`filter_packed_objects_from_bitmap()`. Note that we do not have to
inspect individual bits in the result bitmap, since we know that the
first N (where N is the number of objects in the bitmap's pack/MIDX)
bits correspond to objects which packed by definition.
In other words, for an object to have a bitmap position (not in the
extended index), it must appear in either the bitmap's pack or one of
the packs in its MIDX.
This presents an appealing optimization to us, which is that we can
simply memset() the corresponding number of `eword_t`'s to zero,
provided that we handle any objects which spill into the next word (but
don't occupy all 64 bits of the word itself).
We only have to handle objects in the bitmap's extended index. These
objects may (or may not) appear in one or more pack(s). Since these
objects are known to not appear in either the bitmap's MIDX or pack,
they may be stored as loose, appear in other pack(s), or both.
Before returning a bitmap containing the result of the traversal back to
the caller, drop any bits from the extended index which appear in one or
more packs. This implements the correct behavior for rev-list operations
which use the bitmap index to compute their result.
Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Mon, 6 Nov 2023 22:56:30 +0000 (17:56 -0500)]
list-objects: drop --unpacked non-commit objects from results
In git-rev-list(1), we describe the `--unpacked` option as:
Only useful with `--objects`; print the object IDs that are not in
packs.
This is true of commits, which we discard via get_commit_action(), but
not of the objects they reach. So if we ask for an --objects traversal
with --unpacked, we may get arbitrarily many objects which are indeed
packed.
I am nearly certain this behavior dates back to the introduction of
`--unpacked` via 12d2a18780 ("git rev-list --unpacked" shows only
unpacked commits, 2005-07-03), but I couldn't get that revision of Git
to compile for me. At least as early as v2.0.0 this has been subtly
broken:
There, only the first, third, and sixth entries are loose, with the
remaining set of objects belonging to at least one pack.
The implications for this are relatively benign: bare 'git repack'
invocations which invoke pack-objects with --unpacked are impacted, and
at worst we'll store a few extra objects that should have been excluded.
Arguably changing this behavior is a backwards-incompatible change,
since it alters the set of objects emitted from rev-list queries with
`--objects` and `--unpacked`. But I argue that this change is still
sensible, since the existing implementation deviates from
clearly-written documentation.
The fix here is straightforward: avoid showing any non-commit objects
which are contained in packs by discarding them within list-objects.c,
before they are shown to the user. Note that similar treatment for
`list-objects.c::show_commit()` is not needed, since that case is
already handled by `revision.c::get_commit_action()`.
Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Todd Zullinger [Fri, 3 Nov 2023 14:17:51 +0000 (10:17 -0400)]
RelNotes: improve wording of credential helper notes
Offer a slightly more verbose description of the issue fixed by 7144dee3ec (credential/libsecret: erase matching creds only, 2023-07-26)
and cb626f8e5c (credential/wincred: erase matching creds only,
2023-07-26).
Signed-off-by: Todd Zullinger <tmz@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 7 Nov 2023 01:26:44 +0000 (10:26 +0900)]
Merge branch 'ms/send-email-validate-fix'
"git send-email" did not have certain pieces of data computed yet
when it tried to validate the outging messages and its recipient
addresses, which has been sorted out.
Junio C Hamano [Tue, 7 Nov 2023 01:26:43 +0000 (10:26 +0900)]
Merge branch 'jc/grep-f-relative-to-cwd'
"cd sub && git grep -f patterns" tried to read "patterns" file at
the top level of the working tree; it has been corrected to read
"sub/patterns" instead.
* jc/grep-f-relative-to-cwd:
grep: -f <path> is relative to $cwd
While populating the `repository_format` structure may cause us to
allocate memory, we do not call `clear_repository_format()` in some
places and thus potentially leak memory. Fix this.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
setup: refactor `upgrade_repository_format()` to have common exit
The `upgrade_repository_format()` function has multiple exit paths,
which means that there is no common cleanup of acquired resources.
While this isn't much of a problem right now, we're about to fix a
memory leak that would require us to free the resource in every one of
those exit paths.
Refactor the code to have a common exit path so that the subsequent
memory leak fix becomes easier to implement.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
shallow: fix memory leak when registering shallow roots
When registering shallow roots, we unset the list of parents of the
to-be-registered commit if it's already been parsed. This causes us to
leak memory though because we never free this list. Fix this.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're setting up the Git directory twice in the `test-tool bloom`
helper, once at the beginning of `cmd_bloom()` and once in the local
subcommand implementation `get_bloom_filter_for_commit()`. This can lead
to memory leaks as we'll overwrite variables of `the_repository` with
newly allocated data structures. On top of that it's simply unnecessary.
Fix this by only setting up the Git directory once.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 3 Nov 2023 16:20:19 +0000 (12:20 -0400)]
t: avoid perl's pack/unpack "Q" specifier
The perl script introduced by 86b008ee61 (t: add library for munging
chunk-format files, 2023-10-09) uses pack("Q") and unpack("Q") to read
and write 64-bit values ("quadwords" in perl parlance) from the on-disk
chunk files. However, some builds of perl may not support 64-bit
integers at all, and throw an exception here. While some 32-bit
platforms may still support 64-bit integers in perl (such as our linux32
CI environment), others reportedly don't (the NonStop 32-bit builds).
We can work around this by treating the 64-bit values as two 32-bit
values. We can't ever combine them into a single 64-bit value, but in
practice this is OK. These are representing file offsets, and our files
are much smaller than 4GB. So the upper half of the 64-bit value will
always be 0.
We can just introduce a few helper functions which perform the
translation and double-check our assumptions.
Reported-by: Randall S. Becker <randall.becker@nexbridge.ca> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
In April, GitHub announced that the `macos-13` pool is available:
https://github.blog/changelog/2023-04-24-github-actions-macos-13-is-now-available/.
It is only a matter of time until the `macos-12` pool is going away,
therefore we should switch now, without pressure of a looming deadline.
Since the `macos-13` runners no longer include Python2, we also drop
specifically testing with Python2 and switch uniformly to Python3, see
https://github.com/actions/runner-images/blob/HEAD/images/macos/macos-13-Readme.md
for details about the software available on the `macos-13` pool's
runners.
Also, on macOS 13, Homebrew seems to install a `gcc@9` package that no
longer comes with a regular `unistd.h` (there seems only to be a
`ssp/unistd.h`), and hence builds would fail with:
In file included from base85.c:1:
git-compat-util.h:223:10: fatal error: unistd.h: No such file or directory
223 | #include <unistd.h>
| ^~~~~~~~~~
compilation terminated.
The reason why we install GCC v9.x explicitly is historical, and back in
the days it was because it was the _newest_ version available via
Homebrew: 176441bfb58 (ci: build Git with GCC 9 in the 'osx-gcc' build
job, 2019-11-27).
To reinstate the spirit of that commit _and_ to fix that build failure,
let's switch to the now-newest GCC version: v13.x.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Linus Arver [Thu, 2 Nov 2023 20:51:17 +0000 (20:51 +0000)]
strvec: drop unnecessary include of hex.h
In 41771fa435 (cache.h: remove dependence on hex.h; make other files
include it explicitly, 2023-02-24) we added this as part of a larger
mechanical refactor. But strvec doesn't actually depend on hex.h, so
remove it.
Signed-off-by: Linus Arver <linusa@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 31 Oct 2023 05:23:30 +0000 (14:23 +0900)]
tests: teach callers of test_i18ngrep to use test_grep
They are equivalents and the former still exists, so as long as the
only change this commit makes are to rewrite test_i18ngrep to
test_grep, there won't be any new bug, even if there still are
callers of test_i18ngrep remaining in the tree, or when merged to
other topics that add new uses of test_i18ngrep.
and a good way to sanity check the result yourself is to run the
above in a checkout of c4603c1c (test framework: further deprecate
test_i18ngrep, 2023-10-31) and compare the resulting working tree
contents with the result of applying this patch to the same commit.
You'll see that test_i18ngrep in a few t/lib-*.sh files corrected,
in addition to the manual reproduction.