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>
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>
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>
"To dereference" and "to peel" were sometimes used in in-code
comments and documentation but without description in the glossary.
* vd/glossary-dereference-peel:
glossary: add definitions for dereference & peel
A few stray single quotes crept into the usage string in a2ce608244
(send-email docs: add format-patch options, 2021-10-25). Remove them.
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
"git rev-list --unpacked --objects" failed to exclude packed
non-commit objects, which has been corrected.
* tb/rev-list-unpacked-fix:
pack-bitmap: drop --unpacked non-commit objects from results
list-objects: drop --unpacked non-commit objects from results
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
Another step to deprecate test_i18ngrep.
* jc/test-i18ngrep:
tests: teach callers of test_i18ngrep to use test_grep
test framework: further deprecate test_i18ngrep
"git merge-file" learns a mode to read three contents to be merged
from blob objects.
* bc/merge-file-object-input:
merge-file: add an option to process object IDs
git-merge-file doc: drop "-file" from argument placeholders
"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`
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
Further limit tree depth max to avoid Windows build running out of
the stack space.
* jk/tree-name-and-depth-limit:
max_tree_depth: lower it for MSVC to avoid stack overflows
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>
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:
$ git.compile --version
git version 2.0.0
$ git.compile rev-list --objects --all --unpacked
72791fe96c93f9ec5c311b8bc966ab349b3b5bbe
05713d991c18bbeef7e154f99660005311b5004d v1.0
153ed8b7719c6f5a68ce7ffc43133e95a6ac0fdb
8e4020bb5a8d8c873b25de15933e75cc0fc275df one
9200b628cf9dc883a85a7abc8d6e6730baee589c two
3e6b46e1b7e3b91acce99f6a823104c28aae0b58 unpacked.t
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>
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>
