Commit graph

313 commits

Author SHA1 Message Date
Patrick Steinhardt 673af418d0 environment: guard state depending on a repository
In "environment.h" we have quite a lot of functions and variables that
either explicitly or implicitly depend on `the_repository`.

The implicit set of stateful declarations includes for example variables
which get populated when parsing a repository's Git configuration. This
set of variables is broken by design, as their state often depends on
the last repository config that has been parsed. So they may or may not
represent the state of `the_repository`.

Fixing that is quite a big undertaking, and later patches in this series
will demonstrate a solution for a first small set of those variables. So
for now, let's guard these with `USE_THE_REPOSITORY_VARIABLE` so that
callers are aware of the implicit dependency.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-12 10:15:42 -07:00
Patrick Steinhardt 7ac16649ec path: hide functions using the_repository by default
The path subsystem provides a bunch of legacy functions that compute
paths relative to the "gitdir" and "commondir" directories of the global
`the_repository` variable. Use of those functions is discouraged, and it
is easy to miss the implicit dependency on `the_repository` that calls
to those functions may cause.

With `USE_THE_REPOSITORY_VARIABLE`, we have recently introduced a tool
that allows us to get rid of such functions over time. With this macro,
we can hide away functions that have such implicit dependency such that
other subsystems that want to be free of `the_repository` will not use
them by accident.

Move all path-related functions that use `the_repository` into a block
that gets only conditionally compiled depending on whether or not the
macro has been defined. This also removes all dependencies on that
variable in "path.c", allowing us to remove the definition of said
preprocessor macro.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-13 10:01:01 -07:00
Patrick Steinhardt a973f60dc7 path: stop relying on the_repository in worktree_git_path()
When not provided a worktree, then `worktree_git_path()` will fall back
to returning a path relative to the main repository. In this case, we
implicitly rely on `the_repository` to derive the path. Remove this
dependency by passing a `struct repository` as parameter.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-13 10:01:01 -07:00
Patrick Steinhardt 78f2210b3c path: stop relying on the_repository when reporting garbage
We access `the_repository` in `report_linked_checkout_garbage()` both
directly and indirectly via `get_git_dir()`. Remove this dependency by
instead passing a `struct repository` as parameter.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-13 10:01:01 -07:00
Patrick Steinhardt 61419a42f6 path: expose do_git_common_path() as repo_common_pathv()
With the same reasoning as the preceding commit, expose the function
`do_git_common_path()` as `repo_common_pathv()`. While at it, reorder
parameters such that they match the order we have in `repo_git_pathv()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-13 10:01:00 -07:00
Patrick Steinhardt b6c6bfef31 path: expose do_git_path() as repo_git_pathv()
We're about to move functions of the "path" subsytem that do not use a
`struct repository` into "path.h" as static inlined functions. This will
require us to call `do_git_path()`, which is internal to "path.c".

Expose the function as `repo_git_pathv()` to prepare for the change.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-13 10:01:00 -07:00
Patrick Steinhardt e7da938570 global: introduce USE_THE_REPOSITORY_VARIABLE macro
Use of the `the_repository` variable is deprecated nowadays, and we
slowly but steadily convert the codebase to not use it anymore. Instead,
callers should be passing down the repository to work on via parameters.

It is hard though to prove that a given code unit does not use this
variable anymore. The most trivial case, merely demonstrating that there
is no direct use of `the_repository`, is already a bit of a pain during
code reviews as the reviewer needs to manually verify claims made by the
patch author. The bigger problem though is that we have many interfaces
that implicitly rely on `the_repository`.

Introduce a new `USE_THE_REPOSITORY_VARIABLE` macro that allows code
units to opt into usage of `the_repository`. The intent of this macro is
to demonstrate that a certain code unit does not use this variable
anymore, and to keep it from new dependencies on it in future changes,
be it explicit or implicit

For now, the macro only guards `the_repository` itself as well as
`the_hash_algo`. There are many more known interfaces where we have an
implicit dependency on `the_repository`, but those are not guarded at
the current point in time. Over time though, we should start to add
guards as required (or even better, just remove them).

Define the macro as required in our code units. As expected, most of our
code still relies on the global variable. Nearly all of our builtins
rely on the variable as there is no way yet to pass `the_repository` to
their entry point. For now, declare the macro in "biultin.h" to keep the
required changes at least a little bit more contained.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 10:26:33 -07:00
Junio C Hamano a60c21b720 Merge branch 'ps/undecided-is-not-necessarily-sha1'
Before discovering the repository details, We used to assume SHA-1
as the "default" hash function, which has been corrected. Hopefully
this will smoke out codepaths that rely on such an unwarranted
assumptions.

* ps/undecided-is-not-necessarily-sha1:
  repository: stop setting SHA1 as the default object hash
  oss-fuzz/commit-graph: set up hash algorithm
  builtin/shortlog: don't set up revisions without repo
  builtin/diff: explicitly set hash algo when there is no repo
  builtin/bundle: abort "verify" early when there is no repository
  builtin/blame: don't access potentially unitialized `the_hash_algo`
  builtin/rev-parse: allow shortening to more than 40 hex characters
  remote-curl: fix parsing of detached SHA256 heads
  attr: fix BUG() when parsing attrs outside of repo
  attr: don't recompute default attribute source
  parse-options-cb: only abbreviate hashes when hash algo is known
  path: move `validate_headref()` to its only user
  path: harden validation of HEAD with non-standard hashes
2024-05-30 14:15:11 -07:00
Patrick Steinhardt 0c6bd2b81d path: move validate_headref() to its only user
While `validate_headref()` is only called from `is_git_directory()` in
"setup.c", it is currently implemented in "path.c". Move it over such
that it becomes clear that it is only really used during setup in order
to discover repositories.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-06 22:50:48 -07:00
Patrick Steinhardt a0851cece5 path: harden validation of HEAD with non-standard hashes
The `validate_headref()` function takes a path to a supposed "HEAD" file
and checks whether its format is something that we understand. It is
used as part of our repository discovery to check whether a specific
directory is a Git directory or not.

Part of the validation is a check for a detached HEAD that contains a
plain object ID. To do this validation we use `get_oid_hex()`, which
relies on `the_hash_algo`. At this point in time the hash algo cannot
yet be initialized though because we didn't yet read the Git config.
Consequently, it will always be the SHA1 hash algorithm.

In practice this works alright because `get_oid_hex()` only ends up
checking whether the prefix of the buffer is a valid object ID. And
because SHA1 is shorter than SHA256, the function will successfully
parse SHA256 object IDs, as well.

It is somewhat fragile though and not really the intent to only check
for SHA1. With this in mind, harden the code to use `get_oid_hex_any()`
to check whether the "HEAD" file parses as any known hash.

One might be hard pressed to tighten the check even further and fully
validate the file contents, not only the prefix. In practice though that
wouldn't make a lot of sense as it could be that the repository uses a
hash function that produces longer hashes than SHA256, but which the
current version of Git doesn't understand yet. We'd still want to detect
the repository as proper Git repository in that case, and we will fail
eventually with a proper error message that the hash isn't understood
when trying to set up the repository format.

It follows that we could just leave the current code intact, as in
practice the code change doesn't have any user visible impact. But it
also prepares us for `the_hash_algo` being unset when there is no
repository.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-06 22:50:48 -07:00
Johannes Schindelin 1c00f92eb5 Sync with 2.44.1
* maint-2.44: (41 commits)
  Git 2.44.1
  Git 2.43.4
  Git 2.42.2
  Git 2.41.1
  Git 2.40.2
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  ...
2024-04-29 20:42:30 +02:00
Johannes Schindelin e5e6663e69 Sync with 2.43.4
* maint-2.43: (40 commits)
  Git 2.43.4
  Git 2.42.2
  Git 2.41.1
  Git 2.40.2
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  ...
2024-04-19 12:38:54 +02:00
Johannes Schindelin be348e9815 Sync with 2.41.1
* maint-2.41: (38 commits)
  Git 2.41.1
  Git 2.40.2
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  has_dir_name(): do not get confused by characters < '/'
  docs: document security issues around untrusted .git dirs
  ...
2024-04-19 12:38:46 +02:00
Johannes Schindelin f5b2af06f5 Sync with 2.40.2
* maint-2.40: (39 commits)
  Git 2.40.2
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  has_dir_name(): do not get confused by characters < '/'
  docs: document security issues around untrusted .git dirs
  upload-pack: disable lazy-fetching by default
  ...
2024-04-19 12:38:42 +02:00
Johannes Schindelin f4aa8c8bb1 fetch/clone: detect dubious ownership of local repositories
When cloning from somebody else's repositories, it is possible that,
say, the `upload-pack` command is overridden in the repository that is
about to be cloned, which would then be run in the user's context who
started the clone.

To remind the user that this is a potentially unsafe operation, let's
extend the ownership checks we have already established for regular
gitdir discovery to extend also to local repositories that are about to
be cloned.

This protection extends also to file:// URLs.

The fixes in this commit address CVE-2024-32004.

Note: This commit does not touch the `fetch`/`clone` code directly, but
instead the function used implicitly by both: `enter_repo()`. This
function is also used by `git receive-pack` (i.e. pushes), by `git
upload-archive`, by `git daemon` and by `git http-backend`. In setups
that want to serve repositories owned by different users than the
account running the service, this will require `safe.*` settings to be
configured accordingly.

Also note: there are tiny time windows where a time-of-check-time-of-use
("TOCTOU") race is possible. The real solution to those would be to work
with `fstat()` and `openat()`. However, the latter function is not
available on Windows (and would have to be emulated with rather
expensive low-level `NtCreateFile()` calls), and the changes would be
quite extensive, for my taste too extensive for the little gain given
that embargoed releases need to pay extra attention to avoid introducing
inadvertent bugs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:29:54 +02:00
Junio C Hamano c7a9ec4728 Merge branch 'rs/apply-lift-path-length-limit'
"git apply" has been updated to lift the hardcoded pathname length
limit, which in turn allowed a mksnpath() function that is no
longer used.

* rs/apply-lift-path-length-limit:
  path: remove mksnpath()
  apply: avoid fixed-size buffer in create_one_file()
2024-04-15 14:11:42 -07:00
René Scharfe 708f7e0590 path: remove mksnpath()
Remove the function mksnpath(), which has become unused.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-05 09:49:38 -07:00
Patrick Steinhardt 57db2a094d refs: introduce reftable backend
Due to scalability issues, Shawn Pearce has originally proposed a new
"reftable" format more than six years ago [1]. Initially, this new
format was implemented in JGit with promising results. Around two years
ago, we have then added the "reftable" library to the Git codebase via
a4bbd13be3 (Merge branch 'hn/reftable', 2021-12-15). With this we have
landed all the low-level code to read and write reftables. Notably
missing though was the integration of this low-level code into the Git
code base in the form of a new ref backend that ties all of this
together.

This gap is now finally closed by introducing a new "reftable" backend
into the Git codebase. This new backend promises to bring some notable
improvements to Git repositories:

  - It becomes possible to do truly atomic writes where either all refs
    are committed to disk or none are. This was not possible with the
    "files" backend because ref updates were split across multiple loose
    files.

  - The disk space required to store many refs is reduced, both compared
    to loose refs and packed-refs. This is enabled both by the reftable
    format being a binary format, which is more compact, and by prefix
    compression.

  - We can ignore filesystem-specific behaviour as ref names are not
    encoded via paths anymore. This means there is no need to handle
    case sensitivity on Windows systems or Unicode precomposition on
    macOS.

  - There is no need to rewrite the complete refdb anymore every time a
    ref is being deleted like it was the case for packed-refs. This
    means that ref deletions are now constant time instead of scaling
    linearly with the number of refs.

  - We can ignore file/directory conflicts so that it becomes possible
    to store both "refs/heads/foo" and "refs/heads/foo/bar".

  - Due to this property we can retain reflogs for deleted refs. We have
    previously been deleting reflogs together with their refs to avoid
    file/directory conflicts, which is not necessary anymore.

  - We can properly enumerate all refs. With the "files" backend it is
    not easily possible to distinguish between refs and non-refs because
    they may live side by side in the gitdir.

Not all of these improvements are realized with the current "reftable"
backend implementation. At this point, the new backend is supposed to be
a drop-in replacement for the "files" backend that is used by basically
all Git repositories nowadays. It strives for 1:1 compatibility, which
means that a user can expect the same behaviour regardless of whether
they use the "reftable" backend or the "files" backend for most of the
part.

Most notably, this means we artificially limit the capabilities of the
"reftable" backend to match the limits of the "files" backend. It is not
possible to create refs that would end up with file/directory conflicts,
we do not retain reflogs, we perform stricter-than-necessary checks.
This is done intentionally due to two main reasons:

  - It makes it significantly easier to land the "reftable" backend as
    tests behave the same. It would be tough to argue for each and every
    single test that doesn't pass with the "reftable" backend.

  - It ensures compatibility between repositories that use the "files"
    backend and repositories that use the "reftable" backend. Like this,
    hosters can migrate their repositories to use the "reftable" backend
    without causing issues for clients that use the "files" backend in
    their clones.

It is expected that these artificial limitations may eventually go away
in the long term.

Performance-wise things very much depend on the actual workload. The
following benchmarks compare the "files" and "reftable" backends in the
current version:

  - Creating N refs in separate transactions shows that the "files"
    backend is ~50% faster. This is not surprising given that creating a
    ref only requires us to create a single loose ref. The "reftable"
    backend will also perform auto compaction on updates. In real-world
    workloads we would likely also want to perform pack loose refs,
    which would likely change the picture.

        Benchmark 1: update-ref: create refs sequentially (refformat = files, refcount = 1)
          Time (mean ± σ):       2.1 ms ±   0.3 ms    [User: 0.6 ms, System: 1.7 ms]
          Range (min … max):     1.8 ms …   4.3 ms    133 runs

        Benchmark 2: update-ref: create refs sequentially (refformat = reftable, refcount = 1)
          Time (mean ± σ):       2.7 ms ±   0.1 ms    [User: 0.6 ms, System: 2.2 ms]
          Range (min … max):     2.4 ms …   2.9 ms    132 runs

        Benchmark 3: update-ref: create refs sequentially (refformat = files, refcount = 1000)
          Time (mean ± σ):      1.975 s ±  0.006 s    [User: 0.437 s, System: 1.535 s]
          Range (min … max):    1.969 s …  1.980 s    3 runs

        Benchmark 4: update-ref: create refs sequentially (refformat = reftable, refcount = 1000)
          Time (mean ± σ):      2.611 s ±  0.013 s    [User: 0.782 s, System: 1.825 s]
          Range (min … max):    2.597 s …  2.622 s    3 runs

        Benchmark 5: update-ref: create refs sequentially (refformat = files, refcount = 100000)
          Time (mean ± σ):     198.442 s ±  0.241 s    [User: 43.051 s, System: 155.250 s]
          Range (min … max):   198.189 s … 198.670 s    3 runs

        Benchmark 6: update-ref: create refs sequentially (refformat = reftable, refcount = 100000)
          Time (mean ± σ):     294.509 s ±  4.269 s    [User: 104.046 s, System: 190.326 s]
          Range (min … max):   290.223 s … 298.761 s    3 runs

  - Creating N refs in a single transaction shows that the "files"
    backend is significantly slower once we start to write many refs.
    The "reftable" backend only needs to update two files, whereas the
    "files" backend needs to write one file per ref.

        Benchmark 1: update-ref: create many refs (refformat = files, refcount = 1)
          Time (mean ± σ):       1.9 ms ±   0.1 ms    [User: 0.4 ms, System: 1.4 ms]
          Range (min … max):     1.8 ms …   2.6 ms    151 runs

        Benchmark 2: update-ref: create many refs (refformat = reftable, refcount = 1)
          Time (mean ± σ):       2.5 ms ±   0.1 ms    [User: 0.7 ms, System: 1.7 ms]
          Range (min … max):     2.4 ms …   3.4 ms    148 runs

        Benchmark 3: update-ref: create many refs (refformat = files, refcount = 1000)
          Time (mean ± σ):     152.5 ms ±   5.2 ms    [User: 19.1 ms, System: 133.1 ms]
          Range (min … max):   148.5 ms … 167.8 ms    15 runs

        Benchmark 4: update-ref: create many refs (refformat = reftable, refcount = 1000)
          Time (mean ± σ):      58.0 ms ±   2.5 ms    [User: 28.4 ms, System: 29.4 ms]
          Range (min … max):    56.3 ms …  72.9 ms    40 runs

        Benchmark 5: update-ref: create many refs (refformat = files, refcount = 1000000)
          Time (mean ± σ):     152.752 s ±  0.710 s    [User: 20.315 s, System: 131.310 s]
          Range (min … max):   152.165 s … 153.542 s    3 runs

        Benchmark 6: update-ref: create many refs (refformat = reftable, refcount = 1000000)
          Time (mean ± σ):     51.912 s ±  0.127 s    [User: 26.483 s, System: 25.424 s]
          Range (min … max):   51.769 s … 52.012 s    3 runs

  - Deleting a ref in a fully-packed repository shows that the "files"
    backend scales with the number of refs. The "reftable" backend has
    constant-time deletions.

        Benchmark 1: update-ref: delete ref (refformat = files, refcount = 1)
          Time (mean ± σ):       1.7 ms ±   0.1 ms    [User: 0.4 ms, System: 1.2 ms]
          Range (min … max):     1.6 ms …   2.1 ms    316 runs

        Benchmark 2: update-ref: delete ref (refformat = reftable, refcount = 1)
          Time (mean ± σ):       1.8 ms ±   0.1 ms    [User: 0.4 ms, System: 1.3 ms]
          Range (min … max):     1.7 ms …   2.1 ms    294 runs

        Benchmark 3: update-ref: delete ref (refformat = files, refcount = 1000)
          Time (mean ± σ):       2.0 ms ±   0.1 ms    [User: 0.5 ms, System: 1.4 ms]
          Range (min … max):     1.9 ms …   2.5 ms    287 runs

        Benchmark 4: update-ref: delete ref (refformat = reftable, refcount = 1000)
          Time (mean ± σ):       1.9 ms ±   0.1 ms    [User: 0.5 ms, System: 1.3 ms]
          Range (min … max):     1.8 ms …   2.1 ms    217 runs

        Benchmark 5: update-ref: delete ref (refformat = files, refcount = 1000000)
          Time (mean ± σ):     229.8 ms ±   7.9 ms    [User: 182.6 ms, System: 46.8 ms]
          Range (min … max):   224.6 ms … 245.2 ms    6 runs

        Benchmark 6: update-ref: delete ref (refformat = reftable, refcount = 1000000)
          Time (mean ± σ):       2.0 ms ±   0.0 ms    [User: 0.6 ms, System: 1.3 ms]
          Range (min … max):     2.0 ms …   2.1 ms    3 runs

  - Listing all refs shows no significant advantage for either of the
    backends. The "files" backend is a bit faster, but not by a
    significant margin. When repositories are not packed the "reftable"
    backend outperforms the "files" backend because the "reftable"
    backend performs auto-compaction.

        Benchmark 1: show-ref: print all refs (refformat = files, refcount = 1, packed = true)
          Time (mean ± σ):       1.6 ms ±   0.1 ms    [User: 0.4 ms, System: 1.1 ms]
          Range (min … max):     1.5 ms …   2.0 ms    1729 runs

        Benchmark 2: show-ref: print all refs (refformat = reftable, refcount = 1, packed = true)
          Time (mean ± σ):       1.6 ms ±   0.1 ms    [User: 0.4 ms, System: 1.1 ms]
          Range (min … max):     1.5 ms …   1.8 ms    1816 runs

        Benchmark 3: show-ref: print all refs (refformat = files, refcount = 1000, packed = true)
          Time (mean ± σ):       4.3 ms ±   0.1 ms    [User: 0.9 ms, System: 3.3 ms]
          Range (min … max):     4.1 ms …   4.6 ms    645 runs

        Benchmark 4: show-ref: print all refs (refformat = reftable, refcount = 1000, packed = true)
          Time (mean ± σ):       4.5 ms ±   0.2 ms    [User: 1.0 ms, System: 3.3 ms]
          Range (min … max):     4.2 ms …   5.9 ms    643 runs

        Benchmark 5: show-ref: print all refs (refformat = files, refcount = 1000000, packed = true)
          Time (mean ± σ):      2.537 s ±  0.034 s    [User: 0.488 s, System: 2.048 s]
          Range (min … max):    2.511 s …  2.627 s    10 runs

        Benchmark 6: show-ref: print all refs (refformat = reftable, refcount = 1000000, packed = true)
          Time (mean ± σ):      2.712 s ±  0.017 s    [User: 0.653 s, System: 2.059 s]
          Range (min … max):    2.692 s …  2.752 s    10 runs

        Benchmark 7: show-ref: print all refs (refformat = files, refcount = 1, packed = false)
          Time (mean ± σ):       1.6 ms ±   0.1 ms    [User: 0.4 ms, System: 1.1 ms]
          Range (min … max):     1.5 ms …   1.9 ms    1834 runs

        Benchmark 8: show-ref: print all refs (refformat = reftable, refcount = 1, packed = false)
          Time (mean ± σ):       1.6 ms ±   0.1 ms    [User: 0.4 ms, System: 1.1 ms]
          Range (min … max):     1.4 ms …   2.0 ms    1840 runs

        Benchmark 9: show-ref: print all refs (refformat = files, refcount = 1000, packed = false)
          Time (mean ± σ):      13.8 ms ±   0.2 ms    [User: 2.8 ms, System: 10.8 ms]
          Range (min … max):    13.3 ms …  14.5 ms    208 runs

        Benchmark 10: show-ref: print all refs (refformat = reftable, refcount = 1000, packed = false)
          Time (mean ± σ):       4.5 ms ±   0.2 ms    [User: 1.2 ms, System: 3.3 ms]
          Range (min … max):     4.3 ms …   6.2 ms    624 runs

        Benchmark 11: show-ref: print all refs (refformat = files, refcount = 1000000, packed = false)
          Time (mean ± σ):     12.127 s ±  0.129 s    [User: 2.675 s, System: 9.451 s]
          Range (min … max):   11.965 s … 12.370 s    10 runs

        Benchmark 12: show-ref: print all refs (refformat = reftable, refcount = 1000000, packed = false)
          Time (mean ± σ):      2.799 s ±  0.022 s    [User: 0.735 s, System: 2.063 s]
          Range (min … max):    2.769 s …  2.836 s    10 runs

  - Printing a single ref shows no real difference between the "files"
    and "reftable" backends.

        Benchmark 1: show-ref: print single ref (refformat = files, refcount = 1)
          Time (mean ± σ):       1.5 ms ±   0.1 ms    [User: 0.4 ms, System: 1.0 ms]
          Range (min … max):     1.4 ms …   1.8 ms    1779 runs

        Benchmark 2: show-ref: print single ref (refformat = reftable, refcount = 1)
          Time (mean ± σ):       1.6 ms ±   0.1 ms    [User: 0.4 ms, System: 1.1 ms]
          Range (min … max):     1.4 ms …   2.5 ms    1753 runs

        Benchmark 3: show-ref: print single ref (refformat = files, refcount = 1000)
          Time (mean ± σ):       1.5 ms ±   0.1 ms    [User: 0.3 ms, System: 1.1 ms]
          Range (min … max):     1.4 ms …   1.9 ms    1840 runs

        Benchmark 4: show-ref: print single ref (refformat = reftable, refcount = 1000)
          Time (mean ± σ):       1.6 ms ±   0.1 ms    [User: 0.4 ms, System: 1.1 ms]
          Range (min … max):     1.5 ms …   2.0 ms    1831 runs

        Benchmark 5: show-ref: print single ref (refformat = files, refcount = 1000000)
          Time (mean ± σ):       1.6 ms ±   0.1 ms    [User: 0.4 ms, System: 1.1 ms]
          Range (min … max):     1.5 ms …   2.1 ms    1848 runs

        Benchmark 6: show-ref: print single ref (refformat = reftable, refcount = 1000000)
          Time (mean ± σ):       1.6 ms ±   0.1 ms    [User: 0.4 ms, System: 1.1 ms]
          Range (min … max):     1.5 ms …   2.1 ms    1762 runs

So overall, performance depends on the usecases. Except for many
sequential writes the "reftable" backend is roughly on par or
significantly faster than the "files" backend though. Given that the
"files" backend has received 18 years of optimizations by now this can
be seen as a win. Furthermore, we can expect that the "reftable" backend
will grow faster over time when attention turns more towards
optimizations.

The complete test suite passes, except for those tests explicitly marked
to require the REFFILES prerequisite. Some tests in t0610 are marked as
failing because they depend on still-in-flight bug fixes. Tests can be
run with the new backend by setting the GIT_TEST_DEFAULT_REF_FORMAT
environment variable to "reftable".

There is a single known conceptual incompatibility with the dumb HTTP
transport. As "info/refs" SHOULD NOT contain the HEAD reference, and
because the "HEAD" file is not valid anymore, it is impossible for the
remote client to figure out the default branch without changing the
protocol. This shortcoming needs to be handled in a subsequent patch
series.

As the reftable library has already been introduced a while ago, this
commit message will not go into the details of how exactly the on-disk
format works. Please refer to our preexisting technical documentation at
Documentation/technical/reftable for this.

[1]: https://public-inbox.org/git/CAJo=hJtyof=HRy=2sLP0ng0uZ4=S-DpZ5dR1aF+VHVETKG20OQ@mail.gmail.com/

Original-idea-by: Shawn Pearce <spearce@spearce.org>
Based-on-patch-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-07 08:28:37 -08:00
Patrick Steinhardt 3f921c7591 refs: convert MERGE_AUTOSTASH to become a normal pseudo-ref
Similar to the preceding conversion of the AUTO_MERGE pseudo-ref, let's
convert the MERGE_AUTOSTASH ref to become a normal pseudo-ref as well.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-19 11:10:41 -08:00
Patrick Steinhardt fd7c6ffa9e refs: convert AUTO_MERGE to become a normal pseudo-ref
In 70c70de616 (refs: complete list of special refs, 2023-12-14) we have
inrtoduced a new `is_special_ref()` function that classifies some refs
as being special. The rule is that special refs are exclusively read and
written via the filesystem directly, whereas normal refs exclucsively go
via the refs API.

The intent of that commit was to record the status quo so that we know
to route reads of such special refs consistently. Eventually, the list
should be reduced to its bare minimum of refs which really are special,
namely FETCH_HEAD and MERGE_HEAD.

Follow up on this promise and convert the AUTO_MERGE ref to become a
normal pseudo-ref by using the refs API to both read and write it
instead of accessing the filesystem directly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-19 11:10:41 -08:00
Junio C Hamano ce481ac8b3 Merge branch 'cw/compat-util-header-cleanup'
Further shuffling of declarations across header files to streamline
file dependencies.

* cw/compat-util-header-cleanup:
  git-compat-util: move alloc macros to git-compat-util.h
  treewide: remove unnecessary includes for wrapper.h
  kwset: move translation table from ctype
  sane-ctype.h: create header for sane-ctype macros
  git-compat-util: move wrapper.c funcs to its header
  git-compat-util: move strbuf.c funcs to its header
2023-07-17 11:30:42 -07:00
Junio C Hamano 67e7305e64 Merge branch 'cw/strbuf-cleanup'
Move functions that are not about pure string manipulation out of
strbuf.[ch]

* cw/strbuf-cleanup:
  strbuf: remove global variable
  path: move related function to path
  object-name: move related functions to object-name
  credential-store: move related functions to credential-store file
  abspath: move related functions to abspath
  strbuf: clarify dependency
  strbuf: clarify API boundary
2023-07-06 11:54:46 -07:00
Calvin Wan da9502ff4d treewide: remove unnecessary includes for wrapper.h
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-05 11:41:59 -07:00
Elijah Newren a034e9106f object-store-ll.h: split this header out of object-store.h
The vast majority of files including object-store.h did not need dir.h
nor khash.h.  Split the header into two files, and let most just depend
upon object-store-ll.h, while letting the two callers that need it
depend on the full object-store.h.

After this patch:
    $ git grep -h include..object-store | sort | uniq -c
          2 #include "object-store.h"
        129 #include "object-store-ll.h"

Diff best viewed with `--color-moved`.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21 13:39:54 -07:00
Calvin Wan aba0706832 path: move related function to path
Move path-related function from strbuf.[ch] to path.[ch] so that strbuf
is focused on string manipulation routines with minimal dependencies.

repository.h is no longer a necessary dependency after moving this
function out.

Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-12 13:49:36 -07:00
Elijah Newren 65156bb7ec treewide: remove double forward declaration of read_in_full
cache.h's nature of a dumping ground of includes prevented it from
being included in some compat/ files, forcing us into a workaround
of having a double forward declaration of the read_in_full() function
(see commit 14086b0a13 ("compat/pread.c: Add a forward declaration to
fix a warning", 2007-11-17)).  Now that we have moved functions like
read_in_full() from cache.h to wrapper.h, and wrapper.h isn't littered
with unrelated and scary #defines, get rid of the extra forward
declaration and just have compat/pread.c include wrapper.h.

Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11 08:52:11 -07:00
Elijah Newren 61a7b98264 treewide: remove cache.h inclusion due to setup.h changes
By moving several declarations to setup.h, the previous patch made it
possible to remove the include of cache.h in several source files.  Do
so.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:54 -07:00
Elijah Newren e38da487cc setup.h: move declarations for setup.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:54 -07:00
Elijah Newren 32a8f51061 environment.h: move declarations for environment.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:53 -07:00
Elijah Newren 0b027f6ca7 abspath.h: move absolute path functions from cache.h
This is another step towards letting us remove the include of cache.h in
strbuf.c.  It does mean that we also need to add includes of abspath.h
in a number of C files.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:52 -07:00
Elijah Newren f394e093df treewide: be explicit about dependence on gettext.h
Dozens of files made use of gettext functions, without explicitly
including gettext.h.  This made it more difficult to find which files
could remove a dependence on cache.h.  Make C files explicitly include
gettext.h if they are using it.

However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:51 -07:00
Junio C Hamano d0732a8120 Merge branch 'jk/unused-post-2.39-part2'
More work towards -Wunused.

* jk/unused-post-2.39-part2: (21 commits)
  help: mark unused parameter in git_unknown_cmd_config()
  run_processes_parallel: mark unused callback parameters
  userformat_want_item(): mark unused parameter
  for_each_commit_graft(): mark unused callback parameter
  rewrite_parents(): mark unused callback parameter
  fetch-pack: mark unused parameter in callback function
  notes: mark unused callback parameters
  prio-queue: mark unused parameters in comparison functions
  for_each_object: mark unused callback parameters
  list-objects: mark unused callback parameters
  mark unused parameters in signal handlers
  run-command: mark error routine parameters as unused
  mark "pointless" data pointers in callbacks
  ref-filter: mark unused callback parameters
  http-backend: mark unused parameters in virtual functions
  http-backend: mark argc/argv unused
  object-name: mark unused parameters in disambiguate callbacks
  serve: mark unused parameters in virtual functions
  serve: use repository pointer to get config
  ls-refs: drop config caching
  ...
2023-03-17 14:03:09 -07:00
Jeff King d3dcfa047f mark "pointless" data pointers in callbacks
Both the object_array_filter() and trie_find() functions use callback
functions that let the caller specify which elements match. These
callbacks take a void pointer in case the caller wants to pass in extra
data. But in each case, the single user of these functions just passes
NULL, and the callback ignores the extra pointer.

We could just remove these unused parameters from the callback interface
entirely. But it's good practice to provide such a pointer, as it guides
future callers of the function in the right direction (rather than
tempting them to access global data). Plus it's consistent with other
generic callback interfaces.

So let's instead annotate the unused parameters, in order to silence the
compiler's -Wunused-parameter warning.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-24 09:13:30 -08:00
Elijah Newren 41771fa435 cache.h: remove dependence on hex.h; make other files include it explicitly
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
Junio C Hamano 671bbf7b9d adjust_shared_perm(): leave g+s alone when the group does not matter
Julien Moutinho reports that in an environment where directory does
not have BSD group semantics and requires the g+s to be set (aka
FORCE_DIR_SET_GID), but the system forbids chmod() to touch the g+s
bit, adjust_shared_perm() fails even when the repository is for
private use with perm = 0600, because we unconditionally try to set
the g+s bit.

When we grant extra access based on group membership (i.e. the
directory has either g+r or g+w bit set), which group the directory
and its contents are owned by matters.  But otherwise (e.g. perm is
set to 0600, in Julien's case), flipping g+s bit is not necessary.

Reported-by: Julien Moutinho <julm+git@sourcephile.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-28 14:55:27 -07:00
Junio C Hamano b3b2ddced2 Merge branch 'ds/bundle-uri'
Preliminary code refactoring around transport and bundle code.

* ds/bundle-uri:
  bundle.h: make "fd" version of read_bundle_header() public
  remote: allow relative_url() to return an absolute url
  remote: move relative_url()
  http: make http_get_file() external
  fetch-pack: move --keep=* option filling to a function
  fetch-pack: add a deref_without_lazy_fetch_extended()
  dir API: add a generalized path_match_flags() function
  connect.c: refactor sending of agent & object-format
2022-06-03 14:30:34 -07:00
Ævar Arnfjörð Bjarmason 9fd512c8d6 dir API: add a generalized path_match_flags() function
Add a path_match_flags() function and have the two sets of
starts_with_dot_{,dot_}slash() functions added in
63e95beb08 (submodule: port resolve_relative_url from shell to C,
2016-04-15) and a2b26ffb1a (fsck: convert gitmodules url to URL
passed to curl, 2020-04-18) be thin wrappers for it.

As the latter of those notes the fsck version was copied from the
initial builtin/submodule--helper.c version.

Since the code added in a2b26ffb1a was doing really doing the same as
win32_is_dir_sep() added in 1cadad6f65 (git clone <url>
C:\cygwin\home\USER\repo' is working (again), 2018-12-15) let's move
the latter to git-compat-util.h is a is_xplatform_dir_sep(). We can
then call either it or the platform-specific is_dir_sep() from this
new function.

Let's likewise change code in various other places that was hardcoding
checks for "'/' || '\\'" with the new is_xplatform_dir_sep(). As can
be seen in those callers some of them still concern themselves with
':' (Mac OS classic?), but let's leave the question of whether that
should be consolidated for some other time.

As we expect to make wider use of the "native" case in the future,
define and use two starts_with_dot_{,dot_}slash_native() convenience
wrappers. This makes the diff in builtin/submodule--helper.c much
smaller.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-16 15:02:09 -07:00
Junio C Hamano afe8a9070b tree-wide: apply equals-null.cocci
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-02 09:50:37 -07:00
Johannes Schindelin 93fbff09eb Sync with 2.33.2
* maint-2.33:
  Git 2.33.2
  Git 2.32.1
  Git 2.31.2
  GIT-VERSION-GEN: bump to v2.33.1
  Git 2.30.3
  setup_git_directory(): add an owner check for the top-level directory
  Add a function to determine whether a path is owned by the current user
2022-03-24 00:31:36 +01:00
Johannes Schindelin 201b0c7af6 Sync with 2.31.2
* maint-2.31:
  Git 2.31.2
  Git 2.30.3
  setup_git_directory(): add an owner check for the top-level directory
  Add a function to determine whether a path is owned by the current user
2022-03-24 00:31:28 +01:00
Johannes Schindelin fdcad5a53e Fix GIT_CEILING_DIRECTORIES with C:\ and the likes
When determining the length of the longest ancestor of a given path with
respect to to e.g. `GIT_CEILING_DIRECTORIES`, we special-case the root
directory by returning 0 (i.e. we pretend that the path `/` does not end
in a slash by virtually stripping it).

That is the correct behavior because when normalizing paths, the root
directory is special: all other directory paths have their trailing
slash stripped, but not the root directory's path (because it would
become the empty string, which is not a legal path).

However, this special-casing of the root directory in
`longest_ancestor_length()` completely forgets about Windows-style root
directories, e.g. `C:\`. These _also_ get normalized with a trailing
slash (because `C:` would actually refer to the current directory on
that drive, not necessarily to its root directory).

In fc56c7b34b (mingw: accomodate t0060-path-utils for MSYS2,
2016-01-27), we almost got it right. We noticed that
`longest_ancestor_length()` expects a slash _after_ the matched prefix,
and if the prefix already ends in a slash, the normalized path won't
ever match and -1 is returned.

But then that commit went astray: The correct fix is not to adjust the
_tests_ to expect an incorrect -1 when that function is fed a prefix
that ends in a slash, but instead to treat such a prefix as if the
trailing slash had been removed.

Likewise, that function needs to handle the case where it is fed a path
that ends in a slash (not only a prefix that ends in a slash): if it
matches the prefix (plus trailing slash), we still need to verify that
the path does not end there, otherwise the prefix is not actually an
ancestor of the path but identical to it (and we need to return -1 in
that case).

With these two adjustments, we no longer need to play games in t0060
where we only add `$rootoff` if the passed prefix is different from the
MSYS2 pseudo root, instead we also add it for the MSYS2 pseudo root
itself. We do have to be careful to skip that logic entirely for Windows
paths, though, because they do are not subject to that MSYS2 pseudo root
treatment.

This patch fixes the scenario where a user has set
`GIT_CEILING_DIRECTORIES=C:\`, which would be ignored otherwise.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-03-24 00:21:08 +01:00
Junio C Hamano ed8794ef7a Merge branch 'lh/systemd-timers'
"git maintenance" scheduler learned to use systemd timers as a
possible backend.

* lh/systemd-timers:
  maintenance: add support for systemd timers on Linux
  maintenance: `git maintenance run` learned `--scheduler=<scheduler>`
  cache.h: Introduce a generic "xdg_config_home_for(…)" function
2021-09-20 15:20:40 -07:00
Lénaïc Huard cb7db5bbd5 cache.h: Introduce a generic "xdg_config_home_for(…)" function
Current implementation of `xdg_config_home(filename)` returns
`$XDG_CONFIG_HOME/git/$filename`, with the `git` subdirectory inserted
between the `XDG_CONFIG_HOME` environment variable and the parameter.

This patch introduces a `xdg_config_home_for(subdir, filename)` function
which is more generic. It only concatenates "$XDG_CONFIG_HOME", or
"$HOME/.config" if the former isn’t defined, with the parameters,
without adding `git` in between.

`xdg_config_home(filename)` is now implemented by calling
`xdg_config_home_for("git", filename)` but this new generic function can
be used to compute the configuration directory of other programs.

Signed-off-by: Lénaïc Huard <lenaic@lhuard.fr>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 10:57:04 -07:00
Johannes Schindelin e394a16023 interpolate_path(): allow specifying paths relative to the runtime prefix
Ever since Git learned to detect its install location at runtime, there
was the slightly awkward problem that it was impossible to specify paths
relative to said location.

For example, if a version of Git was shipped with custom SSL
certificates to use, there was no portable way to specify
`http.sslCAInfo`.

In Git for Windows, the problem was "solved" for years by interpreting
paths starting with a slash as relative to the runtime prefix.

However, this is not correct: such paths _are_ legal on Windows, and
they are interpreted as absolute paths in the same drive as the current
directory.

After a lengthy discussion, and an even lengthier time to mull over the
problem and its best solution, and then more discussions, we eventually
decided to introduce support for the magic sequence `%(prefix)/`. If a
path starts with this, the remainder is interpreted as relative to the
detected (runtime) prefix. If built without runtime prefix support, Git
will simply interpolate the compiled-in prefix.

If a user _wants_ to specify a path starting with the magic sequence,
they can prefix the magic sequence with `./` and voilà, the path won't
be expanded.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-26 12:17:16 -07:00
Johannes Schindelin a03b097d63 Use a better name for the function interpolating paths
It is not immediately clear what `expand_user_path()` means, so let's
rename it to `interpolate_path()`. This also opens the path for
interpolating more than just a home directory.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-26 12:17:16 -07:00
Johannes Schindelin 644e6b2c0f expand_user_path(): clarify the role of the real_home parameter
The `real_home` parameter only has an effect when expanding paths
starting with `~/`, not when expanding paths starting with `~<user>/`.
Let's make that clear.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-26 12:17:16 -07:00
Johannes Schindelin 789f6f226b expand_user_path(): remove stale part of the comment
In 395de250d9 (Expand ~ and ~user in core.excludesfile,
commit.template, 2009-11-17), the `user_path()` function was refactored
into the `expand_user_path()`. During that refactoring, the `buf`
parameter was lost, but the code comment above said function still talks
about it. Let's remove that stale part of the comment.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-26 12:17:16 -07:00
Jeff King 801ed010bf t0060: test ntfs/hfs-obscured dotfiles
We have tests that cover various filesystem-specific spellings of
".gitmodules", because we need to reliably identify that path for some
security checks. These are from dc2d9ba318 (is_{hfs,ntfs}_dotgitmodules:
add tests, 2018-05-12), with the actual code coming from e7cb0b4455
(is_ntfs_dotgit: match other .git files, 2018-05-11) and 0fc333ba20
(is_hfs_dotgit: match other .git files, 2018-05-02).

Those latter two commits also added similar matching functions for
.gitattributes and .gitignore. These ended up not being used in the
final series, and are currently dead code. But in preparation for them
being used in some fsck checks, let's make sure they actually work by
throwing a few basic tests at them. Likewise, let's cover .mailmap
(which does need matching code added).

I didn't bother with the whole battery of tests that we cover for
.gitmodules. These functions are all based on the same generic matcher,
so it's sufficient to test most of the corner cases just once.

Note that the ntfs magic prefix names in the tests come from the
algorithm described in e7cb0b4455 (and are different for each file).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-04 11:52:02 +09:00
Elijah Newren 5291828df8 merge-ort: write $GIT_DIR/AUTO_MERGE whenever we hit a conflict
There are a variety of questions users might ask while resolving
conflicts:
  * What changes have been made since the previous (first) parent?
  * What changes are staged?
  * What is still unstaged? (or what is still conflicted?)
  * What changes did I make to resolve conflicts so far?
The first three of these have simple answers:
  * git diff HEAD
  * git diff --cached
  * git diff
There was no way to answer the final question previously.  Adding one
is trivial in merge-ort, since it works by creating a tree representing
what should be written to the working copy complete with conflict
markers.  Simply write that tree to .git/AUTO_MERGE, allowing users to
answer the fourth question with
  * git diff AUTO_MERGE

I avoided using a name like "MERGE_AUTO", because that would be
merge-specific (much like MERGE_HEAD, REBASE_HEAD, REVERT_HEAD,
CHERRY_PICK_HEAD) and I wanted a name that didn't change depending on
which type of operation the merge was part of.

Ensure that paths which clean out other temporary operation-specific
files (e.g. CHERRY_PICK_HEAD, MERGE_MSG, rebase-merge/ state directory)
also clean out this AUTO_MERGE file.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Han-Wen Nienhuys b8825ef233 sequencer: treat REVERT_HEAD as a pseudo ref
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:20:11 -07:00