Commit Graph

76447 Commits (93afe9b060dedd94c20feb8da553cef0e4301176)

Author SHA1 Message Date
Derrick Stolee 93afe9b060 path-walk: create initializer for path lists
The previous change fixed a bug in 'git repack -adf --path-walk' that
was due to an update to how path lists are initialized and missing some
important cases when processing the pending objects.

This change takes the three critical places where path lists are
initialized and combines them into a static method. This simplifies the
callers somewhat while also helping to avoid a missed update in the
future.

The other places where a path list (struct type_and_oid_list) is
initialized is for the following "fixed" lists:

 * Tag objects.
 * Commit objects.
 * Root trees.
 * Tagged trees.
 * Tagged blobs.

These lists are created and consumed in different ways, with only the
root trees being passed into the logic that cares about the
"maybe_interesting" bit. It is appropriate to keep these uses separate.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-25 09:01:17 -07:00
Derrick Stolee febb9d87df path-walk: fix setup of pending objects
Users reported an issue where objects were missing from their local
repositories after a full repack using 'git repack -adf --path-walk'.
This was alarming and took a while to create a reproducer. Here, we fix
the bug and include a test case that would fail without this fix.

The root cause is that certain objects existed in the index and had no
second versions. These objects are usually blobs, though trees can be
included if a cache-tree exists. The issue is that the revision walk
adds these objects to the "pending" list and the path-walk API forgets
to mark the lists it creates at this point as "maybe_interesting". If
these paths only ever have a single version in the history of the repo
(including the current staged version) then the parent directory never
tries to add a new object to the list and mark the list as
"maybe_interesting". Thus, when walking the list later, the group is
skipped as it is expected that no objects are interesting. This happens
even when there are actually no UNINTERESTING objects at all! This is
based on the optimization enabled by the pack.useSparse=true config
option, which is the default.

Thus, we create a test case that demonstrates the many cases of this
issue for reproducibility:

 1. File a/b/c has only one committed version.
 2. Files a/i and x/y only exist as staged changes.
 3. Tree x/ only exists in the cache-tree.

After performing a non-path-walk repack to force all loose objects into
packfiles, run a --path-walk repack followed by 'git fsck'. This fsck is
what fails with the following errors:

  error: invalid object 100644 f2e41136... for 'a/b/c'

    This is the dropped instance of the single-versioned a/b/c file.

  broken link from    tree cfda31d8...
                to    tree 3f725fcd...

    This is the missing tree for the single-versioned a/b/ directory.

  missing blob 0ddf2bae... (a/i)
  missing blob 975fbec8... (x/y)
  missing blob a60d869d... (file)
  missing blob f2e41136... (a/b/c)

  missing tree 3f725fcd... (a/b/)

  dangling tree 5896d7e... (staged root tree)

Note that since the staged root tree is missing, the fsck output cannot
even report that the staged x/ tree is missing as well.

The core problem here is that the "maybe_interesting" member of 'struct
type_and_oid_list' is not initialized to '1'. This member was added in
6333e7ae0b (path-walk: mark trees and blobs as UNINTERESTING,
2024-12-20) in a way to help when creating packfiles for a small commit
range using the sparse path algorithm (enabled by pack.useSparse=true).

The idea here is that the list is marked as "maybe_interesting" if an
object is added that does not have the UNINTERESTING flag on it. Later,
this is checked again in case all objects in the list were marked
UNINTERESTING after that point in time. In this case, the algorithm
skips the list as there is no reason to visit it.

This leads to the problem where the "maybe_interesting" member was not
appropriately initialized when the list is created from pending objects.
Initializing this in the correct places fixes the bug.

To reduce risk of similar bugs around initializing this structure, a
follow-up change will make initializing lists use a shared method.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-25 09:01:17 -07:00
Derrick Stolee c178b02e29 pack-objects: allow --shallow and --path-walk
There does not appear to be anything particularly incompatible about the
--shallow and --path-walk options of 'git pack-objects'. If shallow
commits are to be handled differently, then it is by the revision walk
that defines the commit set and which are interesting or uninteresting.

However, before the previous change, a trivial removal of the warning
would cause a failure in t5500-fetch-pack.sh when
GIT_TEST_PACK_PATH_WALK is enabled. The shallow fetch would provide more
objects than we desired, due to some incorrect behavior of the path-walk
API, especially around walking uninteresting objects.

The recently-added tests in t5538-push-shallow.sh help to confirm this
behavior is working with the --path-walk option if
GIT_TEST_PACK_PATH_WALK is enabled. These tests passed previously due to
the --path-walk feature being disabled in the presence of a shallow
clone.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:41 -07:00
Derrick Stolee 4705889c3d path-walk: add new 'edge_aggressive' option
In preparation for allowing both the --shallow and --path-walk options
in the 'git pack-objects' builtin, create a new 'edge_aggressive' option
in the path-walk API. This option will help walk the boundary more
thoroughly and help avoid sending extra objects during fetches and
pushes.

The only use of the 'edge_hint_aggressive' option in the revision API is
within mark_edges_uninteresting(), which is usually called before
between prepare_revision_walk() and before visiting commits with
get_revision(). In prepare_revision_walk(), the UNINTERESTING commits
are walked until a boundary is found.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:40 -07:00
Derrick Stolee e5394794a5 pack-objects: thread the path-based compression
Adapting the implementation of ll_find_deltas(), create a threaded
version of the --path-walk compression step in 'git pack-objects'.

This involves adding a 'regions' member to the thread_params struct,
allowing each thread to own a section of paths. We can simplify the way
jobs are split because there is no value in extending the batch based on
name-hash the way sections of the object entry array are attempted to be
grouped. We re-use the 'list_size' and 'remaining' items for the purpose
of borrowing work in progress from other "victim" threads when a thread
has finished its batch of work more quickly.

Using the Git repository as a test repo, the p5313 performance test
shows that the resulting size of the repo is the same, but the threaded
implementation gives gains of varying degrees depending on the number of
objects being packed. (This was tested on a 16-core machine.)

Test                        HEAD~1      HEAD
---------------------------------------------------
5313.20: big pack             2.38      1.99 -16.4%
5313.21: big pack size       16.1M     16.0M  -0.2%
5313.24: repack             107.32     45.41 -57.7%
5313.25: repack size        213.3M    213.2M  -0.0%

(Test output is formatted to better fit in message.)

This ~60% reduction in 'git repack --path-walk' time is typical across
all repos I used for testing. What is interesting is to compare when the
overall time improves enough to outperform the --name-hash-version=1
case. These time improvements correlate with repositories with data
shapes that significantly improve their data size as well. The
--path-walk feature frequently takes longer than --name-hash-version=2,
trading some extra computation for some additional compression. The
natural place where this additional computation comes from is the two
compression passes that --path-walk takes, though the first pass is
naturally faster due to the path boundaries avoiding a number of delta
compression attempts.

For example, the microsoft/fluentui repo has significant size reduction
from --name-hash-version=1 to --name-hash-version=2 followed by further
improvements with --path-walk. The threaded computation makes
--path-walk more competitive in time compared to --name-hash-version=2,
though still ~31% more expensive in that metric.

Repack Method       Pack Size       Time
------------------------------------------
Hash v1                439.4M      87.24s
Hash v2                161.7M      21.51s
Path Walk (Before)     142.5M      81.29s
Path Walk (After)      142.5M      28.16s

Similar results hold for the Git repository:

Repack Method       Pack Size       Time
------------------------------------------
Hash v1                248.8M      30.44s
Hash v2                249.0M      30.15s
Path Walk (Before)     213.2M     142.50s
Path Walk (After)      213.3M      45.41s

...as well as the nodejs/node repository:

Repack Method       Pack Size       Time
------------------------------------------
Hash v1                739.9M      71.18s
Hash v2                764.6M      67.82s
Path Walk (Before)     698.1M     208.10s
Path Walk (After)      698.0M      75.10s

Finally, the Linux kernel repository is a good test for this repacking
time change, even though the space savings is more subtle:

Repack Method       Pack Size       Time
------------------------------------------
Hash v1                  2.5G     554.41s
Hash v2                  2.5G     549.62s
Path Walk (before)       2.2G    1562.36s
Path Walk (before)       2.2G     559.00s

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:40 -07:00
Derrick Stolee 206a1bb203 pack-objects: refactor path-walk delta phase
Previously, the --path-walk option to 'git pack-objects' would compute
deltas inline with the path-walk logic. This would make the progress
indicator look like it is taking a long time to enumerate objects, and
then very quickly computed deltas.

Instead of computing deltas on each region of objects organized by tree,
store a list of regions corresponding to these groups. These can later
be pulled from the list for delta compression before doing the "global"
delta search.

This presents a new progress indicator that can be used in tests to
verify that this stage is happening.

The current implementation is not integrated with threads, but we are
setting it up to arrive in the next change.

Since we do not attempt to sort objects by size until after exploring
all trees, we can remove the previous change to t5530 due to a different
error message appearing first.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:40 -07:00
Derrick Stolee 4933152cbb scalar: enable path-walk during push via config
Repositories registered with Scalar are expected to be client-only
repositories that are rather large. This means that they are more likely to
be good candidates for using the --path-walk option when running 'git
pack-objects', especially under the hood of 'git push'. Enable this config
in Scalar repositories.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:40 -07:00
Derrick Stolee 4f7f571204 pack-objects: enable --path-walk via config
Users may want to enable the --path-walk option for 'git pack-objects' by
default, especially underneath commands like 'git push' or 'git repack'.

This should be limited to client repositories, since the --path-walk option
disables bitmap walks, so would be bad to include in Git servers when
serving fetches and clones. There is potential that it may be helpful to
consider when repacking the repository, to take advantage of improved deltas
across historical versions of the same files.

Much like how "pack.useSparse" was introduced and included in
"feature.experimental" before being enabled by default, use the repository
settings infrastructure to make the new "pack.usePathWalk" config enabled by
"feature.experimental" and "feature.manyFiles".

In order to test that this config works, add a new trace2 region around
the path walk code that can be checked by a 'git push' command.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:39 -07:00
Derrick Stolee 5f711504d9 repack: add --path-walk option
Since 'git pack-objects' supports a --path-walk option, allow passing it
through in 'git repack'. This presents interesting testing opportunities for
comparing the different repacking strategies against each other.

Add the --path-walk option to the performance tests in p5313.

For the microsoft/fluentui repo [1] checked out at a specific commit [2],
the --path-walk tests in p5313 look like this:

Test                                                     this tree
-------------------------------------------------------------------------
5313.18: thin pack with --path-walk                      0.08(0.06+0.02)
5313.19: thin pack size with --path-walk                           18.4K
5313.20: big pack with --path-walk                       2.10(7.80+0.26)
5313.21: big pack size with --path-walk                            19.8M
5313.22: shallow fetch pack with --path-walk             1.62(3.38+0.17)
5313.23: shallow pack size with --path-walk                        33.6M
5313.24: repack with --path-walk                         81.29(96.08+0.71)
5313.25: repack size with --path-walk                             142.5M

[1] https://github.com/microsoft/fluentui
[2] e70848ebac1cd720875bccaa3026f4a9ed700e08

Along with the earlier tests in p5313, I'll instead reformat the
comparison as follows:

Repack Method    Pack Size       Time
---------------------------------------
Hash v1             439.4M      87.24s
Hash v2             161.7M      21.51s
Path Walk           142.5M      81.29s

There are a few things to notice here:

 1. The benefits of --name-hash-version=2 over --name-hash-version=1 are
    significant, but --path-walk still compresses better than that
    option.

 2. The --path-walk command is still using --name-hash-version=1 for the
    second pass of delta computation, using the increased name hash
    collisions as a potential method for opportunistic compression on
    top of the path-focused compression.

 3. The --path-walk algorithm is currently sequential and does not use
    multiple threads for delta compression. Threading will be
    implemented in a future change so the computation time will improve
    to better compete in this metric.

There are small benefits in size for my copy of the Git repository:

Repack Method    Pack Size       Time
---------------------------------------
Hash v1             248.8M      30.44s
Hash v2             249.0M      30.15s
Path Walk           213.2M     142.50s

As well as in the nodejs/node repository [3]:

Repack Method    Pack Size       Time
---------------------------------------
Hash v1             739.9M      71.18s
Hash v2             764.6M      67.82s
Path Walk           698.1M     208.10s

[3] https://github.com/nodejs/node

This benefit also repeats in my copy of the Linux kernel repository:

Repack Method    Pack Size       Time
---------------------------------------
Hash v1               2.5G     554.41s
Hash v2               2.5G     549.62s
Path Walk             2.2G    1562.36s

It is important to see that even when the repository shape does not have
many name-hash collisions, there is a slight space boost to be found
using this method.

As this repacking strategy was released in Git for Windows 2.47.0, some
users have reported cases where the --path-walk compression is slightly
worse than the --name-hash-version=2 option. In those cases, it may be
beneficial to combine the two options. However, there has not been a
released version of Git that has both options and I don't have access to
these repos for testing.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:39 -07:00
Derrick Stolee 6e95bf80b5 t5538: add tests to confirm deltas in shallow pushes
It can be notoriously difficult to detect if delta bases are being
computed properly during 'git push'. Construct an example where it will
make a kilobyte worth of difference when a delta base is not found. We
can then use the progress indicators to distinguish between bytes and
KiB depending on whether the delta base is found and used.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:39 -07:00
Derrick Stolee 861d4bc292 pack-objects: introduce GIT_TEST_PACK_PATH_WALK
There are many tests that validate whether 'git pack-objects' works as
expected. Instead of duplicating these tests, add a new test environment
variable, GIT_TEST_PACK_PATH_WALK, that implies --path-walk by default
when specified.

This was useful in testing the implementation of the --path-walk
implementation, helping to find tests that are overly specific to the
default object walk. These include:

 - t0411-clone-from-partial.sh : One test fetches from a repo that does
   not have the boundary objects. This causes the path-based walk to
   fail. Disable the variable for this test.

 - t5306-pack-nobase.sh : Similar to t0411, one test fetches from a repo
   without a boundary object.

 - t5310-pack-bitmaps.sh : One test compares the case when packing with
   bitmaps to the case when packing without them. Since we disable the
   test variable when writing bitmaps, this causes a difference in the
   object list (the --path-walk option adds an extra object). Specify
   --no-path-walk in both processes for the comparison. Another test
   checks for a specific delta base, but when computing dynamically
   without using bitmaps, the base object it too small to be considered
   in the delta calculations so no base is used.

 - t5316-pack-delta-depth.sh : This script cares about certain delta
   choices and their chain lengths. The --path-walk option changes how
   these chains are selected, and thus changes the results of this test.

 - t5322-pack-objects-sparse.sh : This demonstrates the effectiveness of
   the --sparse option and how it combines with --path-walk.

 - t5332-multi-pack-reuse.sh : This test verifies that the preferred
   pack is used for delta reuse when possible. The --path-walk option is
   not currently aware of the preferred pack at all, so finds a
   different delta base.

 - t7406-submodule-update.sh : When using the variable, the --depth
   option collides with the --path-walk feature, resulting in a warning
   message. Disable the variable so this warning does not appear.

I want to call out one specific test change that is only temporary:

 - t5530-upload-pack-error.sh : One test cares specifically about an
   "unable to read" error message. Since the current implementation
   performs delta calculations within the path-walk API callback, a
   different "unable to get size" error message appears. When this
   is changed in a future refactoring, this test change can be reverted.

Similar to GIT_TEST_NAME_HASH_VERSION, we do not add this option to the
linux-TEST-vars CI build as that's already an overloaded build.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:39 -07:00
Derrick Stolee 3ce9e5f293 p5313: add performance tests for --path-walk
The previous change added a --path-walk option to 'git pack-objects'.
Create a performance test that demonstrates the time and space benefits
of the feature.

In order to get an appropriate comparison, we need to avoid reusing
deltas and recompute them from scratch.

Compare the creation of a thin pack representing a small push and the
creation of a relatively large non-thin pack.

Running on my copy of the Git repository results in this data (removing
the repack tests for --name-hash-version):

Test                                                     this tree
------------------------------------------------------------------------
5313.2: thin pack with --name-hash-version=1             0.02(0.01+0.01)
5313.3: thin pack size with --name-hash-version=1                   1.6K
5313.4: big pack with --name-hash-version=1              2.55(4.20+0.26)
5313.5: big pack size with --name-hash-version=1                   16.4M
5313.6: shallow fetch pack with --name-hash-version=1    1.24(2.03+0.08)
5313.7: shallow pack size with --name-hash-version=1               12.2M
5313.10: thin pack with --name-hash-version=2            0.03(0.01+0.01)
5313.11: thin pack size with --name-hash-version=2                  1.6K
5313.12: big pack with --name-hash-version=2             1.91(3.23+0.20)
5313.13: big pack size with --name-hash-version=2                  16.4M
5313.14: shallow fetch pack with --name-hash-version=2   1.06(1.57+0.10)
5313.15: shallow pack size with --name-hash-version=2              12.5M
5313.18: thin pack with --path-walk                      0.03(0.01+0.01)
5313.19: thin pack size with --path-walk                            1.6K
5313.20: big pack with --path-walk                       2.05(3.24+0.27)
5313.21: big pack size with --path-walk                            16.3M
5313.22: shallow fetch pack with --path-walk             1.08(1.66+0.07)
5313.23: shallow pack size with --path-walk                        12.4M

This can be reformatted as follows:

Pack Type            Hash v1   Hash v2     Path Walk
---------------------------------------------------
thin pack    (time)    0.02s      0.03s      0.03s
             (size)    1.6K       1.6K       1.6K
big pack     (time)    2.55s      1.91s      2.05s
             (size)   16.4M      16.4M      16.3M
shallow pack (time)    1.24s      1.06s      1.08s
             (size)   12.2M      12.5M      12.4M

Note that the timing is slower because there is no threading in the
--path-walk case (yet). Also, the shallow pack cases are really not
using the --path-walk logic right now because it is disabled until some
additions are made to the path walk API.

The cases where the --path-walk option really shines is when the default
name-hash is overwhelmed with unhelpful collisions. An open source
example can be found in the microsoft/fluentui repo [1] at a certain
commit [2].

[1] https://github.com/microsoft/fluentui
[2] e70848ebac1cd720875bccaa3026f4a9ed700e08

Running the tests on this repo results in the following comparison table:

Pack Type            Hash v1    Hash v2    Path Walk
---------------------------------------------------
thin pack    (time)    0.36s      0.12s      0.08s
             (size)    1.2M      22.0K      18.4K
big pack     (time)    2.00s      2.90s      2.21s
             (size)   20.4M      25.9M      19.5M
shallow pack (time)    1.41s      1.80s      1.65s
             (size)   34.4M      33.7M      33.6M

Notice in particular that in the small thin pack, the time performance
has improved from 0.36s for --name-hash-version=1 to 0.08s and this is
likely due to the improved size of the resulting pack: 18.4K instead of
1.2M.  The relatively new --name-hash-version=2 is competitive with
--path-walk (0.12s and 22.0K) but not quite as successful.

Finally, running this on a copy of the Linux kernel repository results
in these data points:

Pack Type            Hash v1    Hash v2    Path Walk
---------------------------------------------------
thin pack    (time)    0.03s      0.13s      0.03s
             (size)    4.6K       4.6K       4.6K
big pack     (time)   15.29s     12.32s     13.92s
             (size)  201.1M     159.1M     158.5M
shallow pack (time)   10.88s     22.93s     22.74s
             (size)  269.2M     273.8M     267.7M

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:38 -07:00
Derrick Stolee 9fcfe12ac4 pack-objects: update usage to match docs
The t0450 test script verifies that builtin usage matches the synopsis
in the documentation. Adjust the builtin to match and then remove 'git
pack-objects' from the exception list.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:38 -07:00
Derrick Stolee 70664d2865 pack-objects: add --path-walk option
In order to more easily compute delta bases among objects that appear at
the exact same path, add a --path-walk option to 'git pack-objects'.

This option will use the path-walk API instead of the object walk given
by the revision machinery. Since objects will be provided in batches
representing a common path, those objects can be tested for delta bases
immediately instead of waiting for a sort of the full object list by
name-hash. This has multiple benefits, including avoiding collisions by
name-hash.

The objects marked as UNINTERESTING are included in these batches, so we
are guaranteeing some locality to find good delta bases.

After the individual passes are done on a per-path basis, the default
name-hash is used to find other opportunistic delta bases that did not
match exactly by the full path name.

The current implementation performs delta calculations while walking
objects, which is not ideal for a few reasons. First, this will cause
the "Enumerating objects" phase to be much longer than usual. Second, it
does not take advantage of threading during the path-scoped delta
calculations. Even with this lack of threading, the path-walk option is
sometimes faster than the usual approach. Future changes will refactor
this code to allow for threading, but that complexity is deferred until
later to keep this patch as simple as possible.

This new walk is incompatible with some features and is ignored by
others:

 * Object filters are not currently integrated with the path-walk API,
   such as sparse-checkout or tree depth. A blobless packfile could be
   integrated easily, but that is deferred for later.

 * Server-focused features such as delta islands, shallow packs, and
   using a bitmap index are incompatible with the path-walk API.

 * The path walk API is only compatible with the --revs option, not
   taking object lists or pack lists over stdin. These alternative ways
   to specify the objects currently ignores the --path-walk option
   without even a warning.

Future changes will create performance tests that demonstrate the power
of this approach.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:38 -07:00
Derrick Stolee 4bc0ba0829 pack-objects: extract should_attempt_deltas()
This will be helpful in a future change, which will reuse this logic.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:37 -07:00
Junio C Hamano 87a0bdbf0f Git 2.49-rc2
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-10 08:47:08 -07:00
Junio C Hamano 5d55ad01f5 Merge branch 'tb/fetch-follow-tags-fix'
* tb/fetch-follow-tags-fix:
  fetch: fix following tags when fetching specific OID
2025-03-10 08:45:58 -07:00
Taylor Blau bd52d9a058 fetch: fix following tags when fetching specific OID
In 3f763ddf28 (fetch: set remote/HEAD if it does not exist, 2024-11-22),
unconditionally adds "HEAD" to the list of ref prefixes we send to the
server.

This breaks a core assumption that the list of prefixes we send to the
server is complete. We must either send all prefixes we care about, or
none at all (in the latter case the server then advertises everything).

The tag following code is careful to only add "refs/tags/" to the list
of prefixes if there are already entries in the prefix list. But because
the new code from 3f763ddf28 runs after the tag code, and because it
unconditionally adds to the prefix list, we may end up with a prefix
list that _should_ have "refs/tags/" in it, but doesn't.

When that is the case, the server does not advertise any tags, and our
auto-following breaks because we never learned about any tags in the
first place.

Fix this by only adding "HEAD" to the ref prefixes when we know that we
are already limiting the advertisement. In either case we'll learn about
HEAD (either through the limited advertisement, or implicitly through a
full advertisement).

Reported-by: Igor Todorovski <itodorov@ca.ibm.com>
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>
2025-03-07 16:15:18 -08:00
Junio C Hamano a36e024e98 Merge branch 'js/win-2.49-build-fixes'
Hotfix to help building Git-for-Windows.

* js/win-2.49-build-fixes:
  cmake: generalize the handling of the `CLAR_TEST_OBJS` list
  meson: fix sorting
  ident: stop assuming that `gw_gecos` is writable
2025-03-06 14:06:32 -08:00
Junio C Hamano bc86ef104a Merge branch 'pw/repo-layout-doc-update'
Some future breaking changes would remove certain parts of the
default repository, which were still described even when the
documents were built for the future with WITH_BREAKING_CHANGES.

* pw/repo-layout-doc-update:
  docs: fix repository-layout when building with breaking changes
2025-03-06 14:06:31 -08:00
Junio C Hamano 62c58891e1 Merge branch 'tz/doc-txt-to-adoc-fixes'
Fallouts from recent renaming of documentation files from .txt
suffix to the new .adoc suffix have been corrected.

* tz/doc-txt-to-adoc-fixes: (38 commits)
  xdiff: *.txt -> *.adoc fixes
  unpack-trees.c: *.txt -> *.adoc fixes
  transport.h: *.txt -> *.adoc fixes
  trace2/tr2_sysenv.c: *.txt -> *.adoc fixes
  trace2.h: *.txt -> *.adoc fixes
  t6434: *.txt -> *.adoc fixes
  t6012: *.txt -> *.adoc fixes
  t/helper/test-rot13-filter.c: *.txt -> *.adoc fixes
  simple-ipc.h: *.txt -> *.adoc fixes
  setup.c: *.txt -> *.adoc fixes
  refs.h: *.txt -> *.adoc fixes
  pseudo-merge.h: *.txt -> *.adoc fixes
  parse-options.h: *.txt -> *.adoc fixes
  object-name.c: *.txt -> *.adoc fixes
  list-objects-filter-options.h: *.txt -> *.adoc fixes
  fsck.h: *.txt -> *.adoc fixes
  diffcore.h: *.txt -> *.adoc fixes
  diff.h: *.txt -> *.adoc fixes
  contrib/long-running-filter: *.txt -> *.adoc fixes
  config.c: *.txt -> *.adoc fixes
  ...
2025-03-06 14:06:31 -08:00
Johannes Schindelin 9709163687 cmake: generalize the handling of the `CLAR_TEST_OBJS` list
A late-comer to the v2.49.0 party, `sk/unit-test-oid`, added yet another
array item to `CLAR_TEST_OBJS`, causing the `win+VS build` job to fail
with symptoms like this one:

  unit-tests-lib.lib(u-oid-array.obj) : error LNK2019: unresolved
  external symbol cl_parse_any_oid referenced in function fill_array

This is a similar scenario to the one that forced me to write
8afda42fce (cmake: generalize the handling of the `UNIT_TEST_OBJS`
list, 2024-09-18): The hard-coded echo of `CLAR_TEST_OBJS` in
`CMakeLists.txt` that recapitulates faithfully what was already
hard-coded in `Makefile` would either have to be updated whack-a-mole
style, or generalized.

Just like I chose the latter option for `UNIT_TEST_OBJS`, I now do the
same for `CLAR_TEST_OBJS`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-06 08:35:08 -08:00
Johannes Schindelin 31761f3911 meson: fix sorting
In 904339edbd (Introduce support for the Meson build system,
2024-12-06) the `meson.build` file was introduced, adding also a
Windows-specific list of source files. This list was obviously meant to
be sorted alphabetically, but there is one mistake. Let's fix that.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-06 08:35:07 -08:00
Johannes Schindelin 4478ad37a7 ident: stop assuming that `gw_gecos` is writable
In 590e081dea (ident: add NO_GECOS_IN_PWENT for systems without
pw_gecos in struct passwd, 2011-05-19), code was introduced to iterate
over the `gw_gecos` field; The loop variable is of type `char *`, which
assumes that `gw_gecos` is writable.

However, it is not necessarily writable (and it is a bad idea to have it
writable in the first place), so let's switch the loop variable type to
`const char *`.

This is not a new problem, but what is new is the Meson build. While it
does not trigger in CI builds, imitating the commands of
`ci/run-build-and-tests.sh` in a regular Git for Windows SDK (`meson
setup build . --fatal-meson-warnings --warnlevel 2 --werror --wrap-mode
nofallback -Dfuzzers=true` followed by `meson compile -C build --`
results in this beautiful error:

  "cc" [...] -o libgit.a.p/ident.c.obj "-c" ../ident.c
  ../ident.c: In function 'copy_gecos':
  ../ident.c:68:18: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
     68 |         for (src = get_gecos(w); *src && *src != ','; src++) {
        |                  ^
  cc1.exe: all warnings being treated as errors

Now, why does this not trigger in CI? The answer is as simple as it is
puzzling: The `win+Meson` job completely side-steps Git for Windows'
development environment, opting instead to use the GCC that is on the
`PATH` in GitHub-hosted `windows-latest` runners. That GCC is pinned to
v12.2.0 and targets the UCRT (unlikely to change any time soon, see
https://github.com/actions/runner-images/blob/win25/20250303.1/images/windows/toolsets/toolset-2022.json#L132-L141).
That is in stark contrast to Git for Windows, which uses GCC v14.2.0 and
targets MSVCRT. Git for Windows' `Makefile`-based build also obviously
uses different compiler flags, otherwise this compile error would have
had plenty of opportunity in almost 14 years to surface.

In other words, contrary to my expectations, the `win+Meson` job is
ill-equipped to replace the `win build` job because it exercises a
completely different tool version/compiler flags vector than what Git
for Windows needs.

Nevertheless, there is currently this huge push, including breaking
changes after -rc1 and all, for switching to Meson. Therefore, we need
to make it work, somehow, even in Git for Windows' SDK, hence this
patch, at this point in time.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-06 08:35:07 -08:00
Junio C Hamano e969bc8759 A few more after -rc1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-05 10:37:53 -08:00
Junio C Hamano 3dea2ad17d Merge branch 'rs/reftable-reader-new-leakfix'
Leakfix.

* rs/reftable-reader-new-leakfix:
  reftable: release name on reftable_reader_new() error
2025-03-05 10:37:46 -08:00
Junio C Hamano 22fab08fb8 Merge branch 'pw/build-meson-technical-and-howto-docs'
Meson-based build procedure forgot to build some docs, which has
been corrected.

* pw/build-meson-technical-and-howto-docs:
  meson: fix building technical and howto docs
2025-03-05 10:37:45 -08:00
Junio C Hamano cdf458c60e Merge branch 'kn/ref-migrate-skip-reflog'
Usage string of "git refs" has been corrected.

* kn/ref-migrate-skip-reflog:
  refs: show --no-reflog in the help text
2025-03-05 10:37:45 -08:00
Junio C Hamano e2334d2f35 Merge branch 'jc/breaking-changes-early-adopter-option'
Doc update.

* jc/breaking-changes-early-adopter-option:
  BreakingChanges: clarify the procedure
2025-03-05 10:37:45 -08:00
Junio C Hamano 3334de6494 Merge branch 'dm/editorconfig-bash-is-like-sh'
The editorconfig file is updated to tell us that bash scripts are
similar to general Bourne shell scripts.

* dm/editorconfig-bash-is-like-sh:
  editorconfig: add .bash extension
2025-03-05 10:37:44 -08:00
Junio C Hamano 2c6fd30198 Merge branch 'cc/lop-remote'
Large-object promisor protocol extension.

* cc/lop-remote:
  doc: add technical design doc for large object promisors
  promisor-remote: check advertised name or URL
  Add 'promisor-remote' capability to protocol v2
2025-03-05 10:37:44 -08:00
Junio C Hamano 6024f321d4 Merge branch 'sk/unit-test-oid'
Convert a few unit tests to the clar framework.

* sk/unit-test-oid:
  t/unit-tests: convert oidtree test to use clar test framework
  t/unit-tests: convert oidmap test to use clar test framework
  t/unit-tests: convert oid-array test to use clar test framework
  t/unit-tests: implement clar specific oid helper functions
2025-03-05 10:37:43 -08:00
Junio C Hamano feffb34257 Merge branch 'ps/path-sans-the-repository'
The path.[ch] API takes an explicit repository parameter passed
throughout the callchain, instead of relying on the_repository
singleton instance.

* ps/path-sans-the-repository:
  path: adjust last remaining users of `the_repository`
  environment: move access to "core.sharedRepository" into repo settings
  environment: move access to "core.hooksPath" into repo settings
  repo-settings: introduce function to clear struct
  path: drop `git_path()` in favor of `repo_git_path()`
  rerere: let `rerere_path()` write paths into a caller-provided buffer
  path: drop `git_common_path()` in favor of `repo_common_path()`
  worktree: return allocated string from `get_worktree_git_dir()`
  path: drop `git_path_buf()` in favor of `repo_git_path_replace()`
  path: drop `git_pathdup()` in favor of `repo_git_path()`
  path: drop unused `strbuf_git_path()` function
  path: refactor `repo_submodule_path()` family of functions
  submodule: refactor `submodule_to_gitdir()` to accept a repo
  path: refactor `repo_worktree_path()` family of functions
  path: refactor `repo_git_path()` family of functions
  path: refactor `repo_common_path()` family of functions
2025-03-05 10:37:43 -08:00
Phillip Wood 92f8da8de3 docs: fix repository-layout when building with breaking changes
Since commit 8ccc75c245 (remote: announce removal of "branches/" and
"remotes/", 2025-01-22) enabling WITH_BREAKING_CHANGES when building git
removes support for reading branches from ".git/branches" and remotes
from ".git/remotes". However those locations are still documented in
gitrepository-layout.adoc even though the build does not support them.

Rectify this by adding a new document attribute "with-breaking-changes"
and use it to make the inclusion of those sections of the documentation
conditional. Note that the name of the attribute does not match the test
prerequisite WITHOUT_BREAKING_CHANGES added in c5bc9a7f94 (Makefile:
wire up build option for deprecated features, 2025-01-22). This is to
avoid the awkward double negative ifndef::without_breaking_changes for
documentation that should be included when WITH_BREAKING_CHANGES is
enabled. The test prerequisite will be renamed to match the
documentation attribute in a future patch series.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-05 07:25:11 -08:00
René Scharfe bad7910399 reftable: release name on reftable_reader_new() error
If block_source_read_block() or parse_footer() fail, we leak the "name"
member of struct reftable_reader in reftable_reader_new().  Release it.

Reported by: H Z <shiyuyuranzh@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-04 09:21:39 -08:00
Junio C Hamano 6a64ac7b01 Git 2.49-rc1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-04 08:19:20 -08:00
Junio C Hamano 6dff5de1da refs: show --no-reflog in the help text
We forgot that we must keep the documentation and help text in sync.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 14:51:29 -08:00
Todd Zullinger 61cd812130 xdiff: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:27 -08:00
Todd Zullinger d6b67cefb5 unpack-trees.c: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:27 -08:00
Todd Zullinger ee00ef41f2 transport.h: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:27 -08:00
Todd Zullinger 15db9a895d trace2/tr2_sysenv.c: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:26 -08:00
Todd Zullinger 508cf7f5d8 trace2.h: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:26 -08:00
Todd Zullinger 366074dc18 t6434: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:26 -08:00
Todd Zullinger 8ea7d41f17 t6012: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:26 -08:00
Todd Zullinger e680c62542 t/helper/test-rot13-filter.c: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:25 -08:00
Todd Zullinger 9f04cd7c61 simple-ipc.h: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:25 -08:00
Todd Zullinger 0543300b59 setup.c: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:25 -08:00
Todd Zullinger 72d385824a refs.h: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:24 -08:00
Todd Zullinger dc657d5625 pseudo-merge.h: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:24 -08:00
Todd Zullinger 458f8b0eab parse-options.h: *.txt -> *.adoc fixes
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:24 -08:00