Commit Graph

75032 Commits

Author SHA1 Message Date
bd1b88dc7a config: document remote.*.url/pushurl interaction
The documentation for these keys gives a very terse definition and
points you to the fetch/push manpages. But from reading those pages it
was not at all obvious to me that:

  - these are keys that can be defined multiple times with meaningful
    behavior (especially remote.*.url)

  - the way that pushurl overrides url (the git-push page does mention
    that "pushurl defaults to url", but it is not immediately clear what
    a multi-valued url would do in that situation).

Let's try to summarize the current behavior.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:34:38 -07:00
b68118d2e8 remote: simplify url/pushurl selection
When we want to know the push urls for a remote, there is some simple
logic:

  - if the user configured any remote.*.pushurl keys, then those make
    the complete set of push urls

  - otherwise we push to all urls in remote.*.url

Many spots implement this with a level of indirection, assigning to a
local url/url_nr pair. But since both arrays are now strvecs, we can
just use a pointer to select the appropriate strvec, shortening the code
a bit.

Even though this is now a one-liner, since it is application logic that
is present in so many places, it's worth abstracting a helper function.
In fact, we already have such a function, but it's local to
builtin/push.c. So we'll just make it available everywhere via remote.h.

There are two spots to pay special attention to here:

  1. in builtin/remote.c's get_url(), we are selecting first based on
     push_mode and then falling back to "url" when we're in push_mode
     but no pushurl is defined. The updated code makes that much more
     clear, compared to the original which had an "else" fall-through.

  2. likewise in that file's set_url(), we _only_ respect push_mode,
     sine the point is that we are adding to pushurl in that case
     (whether it is empty or not). And thus it does not use our helper
     function.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:34:38 -07:00
8e804415fd remote: use strvecs to store remote url/pushurl
Now that the url/pushurl fields of "struct remote" own their strings, we
can switch from bare arrays to strvecs. This has a few advantages:

  - push/clear are now one-liners

  - likewise the free+assigns in alias_all_urls() can use
    strvec_replace()

  - we now use size_t for storage, avoiding possible overflow

  - this will enable some further cleanups in future patches

There's quite a bit of fallout in the code that reads these fields, as
it tends to access these arrays directly. But it's mostly a mechanical
replacement of "url_nr" with "url.nr", and "url[i]" with "url.v[i]",
with a few variations (e.g. "*url" could become "*url.v", but I used
"url.v[0]" for consistency).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:34:38 -07:00
52595c155a remote: transfer ownership of memory in add_url(), etc
Many of the internal functions in remote.c take const strings and store
them forever in instances of "struct remote". Since the functions are
internal and callers are aware of the convention, this seems to mostly
work and not cause leaks. But there are some issues:

  - it's impossible to clear any of the arrays, because the data
    dependencies between them are too muddled (if you free() a string,
    it might also be referenced from another array, causing a
    user-after-free; but if you don't, that might be the last reference,
    causing a leak).

    This is mostly of interest for further refactoring and features, but
    there's at least one spot that's already a problem. In alias_all_urls(),
    we replace elements of remote->url and remote->pushurl with their
    aliased forms, dropping references to the original.

  - sometimes strings from outside callers make their way in. For
    example, calling remote_get("foo") when there is no configured "foo"
    remote will create a remote struct with the single url "foo". But
    we'll do so by holding on to the string passed to remote_get()
    forever.

    In practice I think this works out because we'd usually pass in a
    string that lasts the length of the program (a string literal, or
    argv reference, or other data structure allocated in the main
    function). But it's a rather subtle requirement.

Instead, let's have remote->url and remote->pushurl own their string
memory. They'll copy the const strings that are passed in, and callers
can stop making their own copies. Likewise, when we overwrite an entry,
we can free the memory it points to, fixing the leak mentioned above.

We'll leave the struct members as "const" since they are visible to the
outside world, and shouldn't usually be touched. This requires casting
on free() for now, but we'll clean that further in a future patch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:34:37 -07:00
aa0595fbd6 remote: refactor alias_url() memory ownership
The alias_url() function may return either a newly allocated string
(which the caller must take ownership of), or the original const "url"
parameter that was passed in.

This often works OK because callers are generally passing in a "url"
that they expect to retain ownership of anyway. So whether we got back
the original or a new string, we're always interested in storing it
forever. But I suspect there are some possible leaks here (e.g.,
add_url_alias() may end up discarding the original "url").

Whether there are active leaks or not, this is a confusing setup that
makes further refactoring of memory ownership harder. So instead of
returning the original string, return NULL, forcing callers to decide
what to do with it explicitly. We can then build further cleanups on top
of that.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:34:37 -07:00
0295ce7cbf archive: fix check for missing url
Running "git archive --remote" checks that we have at least one url for
the remote. It does so by looking at remote.url[0], but that won't work;
if we have no url at all, then remote.url will be NULL, and we'll
segfault.

Check url_nr instead, which is a more direct way of asking what we
want.

You can trigger the segfault like this:

  git -c remote.foo.vcs=bar archive --remote=foo

but I didn't bother adding a test. This is the tip of the iceberg for
no-url remotes, and a later patch will improve that situation. I just
wanted to clean up this bug so it didn't make further refactoring of
this code more confusing.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:34:37 -07:00
028bb23a61 BreakingChanges: document that we do not plan to deprecate git-checkout
The git-checkout(1) command is seen by many as hard to understand
because it connects two somewhat unrelated features: switching between
branches and restoring worktree files from arbitrary revisions. In 2019,
we thus implemented two new commands git-switch(1) and git-restore(1) to
split out these separate concerns into standalone functions.

This "replacement" of git-checkout(1) has repeatedly triggered concerns
for our userbase that git-checkout(1) will eventually go away. This is
not the case though: the use of that command is still widespread, and it
is not expected that this will change anytime soon.

Document that all three commands will remain for the foreseeable future.
This decision may be revisited in case we ever figure out that most
everyone has given up on any of the commands.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:08:52 -07:00
fcf0f4801d BreakingChanges: document removal of grafting
The grafting mechanism for objects has been deprecated in e650d0643b
(docs: mark info/grafts as outdated, 2014-03-05), which is more than a
decade ago. The mechanism can lead to hard-to-debug issues and has a
superior replacement with replace refs.

Follow through with the deprecation and mark grafts for removal in Git
3.0.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:08:52 -07:00
6ccf041d1d BreakingChanges: document upcoming change from "sha1" to "sha256"
Starting with 8e42eb0e9a (doc: sha256 is no longer experimental,
2023-07-31), the "sha256" object format is no longer considered to be
experimental. Furthermore, the SHA-1 hash function is actively
recommended against by for example NIST and FIPS 140-2, and attacks
against it are becoming more practical both due to new weaknesses
(SHAppening, SHAttered, Shambles) and due to the ever-increasing
computing power. It is only a matter of time before it can be considered
to be broken completely.

Let's plan for this event by being active instead of waiting for it to
happend and announce that the default object format is going to change
from "sha1" to "sha256" with Git 3.0.

All major Git implementations (libgit2, JGit, go-git) support the
"sha256" object format and are thus prepared for this change. The most
important missing piece in the puzzle is support in forges. But while
GitLab recently gained experimental support for the "sha256" object
format though, to the best of my knowledge GitHub doesn't support it
yet. Ideally, announcing this upcoming change will encourage forges to
start building that support.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:08:52 -07:00
57ec9254eb docs: introduce document to announce breaking changes
Over time, Git has grown quite a lot. With this evolution, many ideas
that were sensible at the time they were introduced are not anymore and
are thus considered to be deprecated. And while some deprecations may be
noted in manpages, most of them are actually deprecated in the "hive
mind" of the Git community, only.

Introduce a new document that tracks such breaking changes, but also
deprecations which we are not willing to go through with, to address
this issue. This document serves multiple purposes:

  - It is a way to facilitate discussion around proposed deprecations.

  - It allows users to learn about deprecations and speak up in case
    they have good reasons why a certain feature should not be
    deprecated.

  - It states intent and documents where the Git project wants to go,
    both in the case where we want to deprecate, but also in the case
    where we don't want to deprecate a specific feature.

The document is _not_ intended to cast every single discussion into
stone. It is supposed to be a living document that may change over time
when there are good reasons for it to change.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 09:08:52 -07:00
10aa7c74a2 Merge branch 'gt/unit-test-oidtree' into ps/use-the-repository
* gt/unit-test-oidtree:
  t/: migrate helper/test-oidtree.c to unit-tests/t-oidtree.c
2024-06-13 09:39:46 -07:00
092b33da2b Merge branch 'ps/ref-storage-migration' into ps/use-the-repository
* ps/ref-storage-migration:
  builtin/refs: new command to migrate ref storage formats
  refs: implement logic to migrate between ref storage formats
  refs: implement removal of ref storages
  worktree: don't store main worktree twice
  reftable: inline `merged_table_release()`
  refs/files: fix NULL pointer deref when releasing ref store
  refs/files: extract function to iterate through root refs
  refs/files: refactor `add_pseudoref_and_head_entries()`
  refs: allow to skip creation of reflog entries
  refs: pass storage format to `ref_store_init()` explicitly
  refs: convert ref storage format to an enum
  setup: unset ref storage when reinitializing repository version
2024-06-13 09:39:08 -07:00
f1160393c1 commit-graph: increment progress indicator
This fixes a bug that was introduced by 368d19b0b7 (commit-graph:
refactor compute_topological_levels(), 2023-03-20): Previously, the
progress indicator was updated from `i + 1` where `i` is the loop
variable of the enclosing `for` loop. After this patch, the update used
`info->progress_cnt + 1` instead, however, unlike `i`, the
`progress_cnt` attribute was not incremented. Let's increment it.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
[jc: squashed in a test update from Patrick Steinhardt]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-12 13:52:14 -07:00
d63586cb31 The thirteenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-12 13:37:18 -07:00
2a061a62e2 Merge branch 'gt/decorate-unit-test'
A test helper that essentially is unit tests on the "decorate"
logic has been rewritten using the unit-tests framework.

* gt/decorate-unit-test:
  t/: migrate helper/test-example-decorate to the unit testing framework
2024-06-12 13:37:18 -07:00
51ea70c18a Merge branch 'jk/sparse-leakfix'
Many memory leaks in the sparse-checkout code paths have been
plugged.

* jk/sparse-leakfix:
  sparse-checkout: free duplicate hashmap entries
  sparse-checkout: free string list after displaying
  sparse-checkout: free pattern list in sparse_checkout_list()
  sparse-checkout: free sparse_filename after use
  sparse-checkout: refactor temporary sparse_checkout_patterns
  sparse-checkout: always free "line" strbuf after reading input
  sparse-checkout: reuse --stdin buffer when reading patterns
  dir.c: always copy input to add_pattern()
  dir.c: free removed sparse-pattern hashmap entries
  sparse-checkout: clear patterns when init() sees existing sparse file
  dir.c: free strings in sparse cone pattern hashmaps
  sparse-checkout: pass string literals directly to add_pattern()
  sparse-checkout: free string list in write_cone_to_file()
2024-06-12 13:37:17 -07:00
c2f79440ac Merge branch 'jk/cap-exclude-file-size'
An overly large ".gitignore" files are now rejected silently.

* jk/cap-exclude-file-size:
  dir.c: reduce max pattern file size to 100MB
  dir.c: skip .gitignore, etc larger than INT_MAX
2024-06-12 13:37:17 -07:00
b8bdb2f283 Merge branch 'jc/safe-directory-leading-path'
The safe.directory configuration knob has been updated to
optionally allow leading path matches.

* jc/safe-directory-leading-path:
  safe.directory: allow "lead/ing/path/*" match
2024-06-12 13:37:16 -07:00
22cf18fd9e Merge branch 'gt/t-hash-unit-test'
A pair of test helpers that essentially are unit tests on hash
algorithms have been rewritten using the unit-tests framework.

* gt/t-hash-unit-test:
  t/: migrate helper/test-{sha1, sha256} to unit-tests/t-hash
  strbuf: introduce strbuf_addstrings() to repeatedly add a string
2024-06-12 13:37:15 -07:00
56346ba24e Merge branch 'cp/reftable-unit-test'
Basic unit tests for reftable have been reimplemented under the
unit test framework.

* cp/reftable-unit-test:
  t: improve the test-case for parse_names()
  t: add test for put_be16()
  t: move tests from reftable/record_test.c to the new unit test
  t: move tests from reftable/stack_test.c to the new unit test
  t: move reftable/basics_test.c to the unit testing framework
2024-06-12 13:37:14 -07:00
a39e28ace7 Merge branch 'jc/t1517-more'
A new test was added to ensure git commands that are designed to
run outside repositories do work.

* jc/t1517-more:
  imap-send: minimum leakfix
  t1517: more coverage for commands that work without repository
2024-06-12 13:37:14 -07:00
ed54840872 t/: migrate helper/test-oidtree.c to unit-tests/t-oidtree.c
helper/test-oidtree.c along with t0069-oidtree.sh test the oidtree.h
library, which is a wrapper around crit-bit tree. Migrate them to
the unit testing framework for better debugging and runtime
performance. Along with the migration, add an extra check for
oidtree_each() test, which showcases how multiple expected matches can
be given to check_each() helper.

To achieve this, introduce a new library called 'lib-oid.h'
exclusively for the unit tests to use. It currently mainly includes
utility to generate object_id from an arbitrary hex string
(i.e. '12a' -> '12a0000000000000000000000000000000000000'). This also
handles the hash algo selection based on GIT_TEST_DEFAULT_HASH.
This library will also be helpful when we port other unit tests such
as oid-array, oidset etc.

Helped-by: Junio C Hamano <gitster@pobox.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
[jc: small fixlets squashed in]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-12 13:33:20 -07:00
037df60013 object-name: don't try to abbreviate to lengths greater than hexsz
When given a length that equals the current hash algorithm's hex size,
then `repo_find_unique_abbrev_r()` exits early without trying to find an
abbreviation. This is only sensible because there is nothing to
abbreviate in the first place, so searching through objects to find a
unique prefix would be a waste of compute.

What we don't handle though is the case where the user passes a length
greater than the hash length. This is fine in practice as we still
compute the correct result. But at the very least, this is a waste of
resources as we try to abbreviate a value that cannot be abbreviated,
which causes us to hit the object database.

Start to explicitly handle values larger than hexsz to avoid this
performance penalty, which leads to a measureable speedup. The following
benchmark has been executed in linux.git:

  Benchmark 1: git -c core.abbrev=9000 log --abbrev-commit (revision = HEAD~)
    Time (mean ± σ):     12.812 s ±  0.040 s    [User: 12.225 s, System: 0.554 s]
    Range (min … max):   12.723 s … 12.857 s    10 runs

  Benchmark 2: git -c core.abbrev=9000 log --abbrev-commit (revision = HEAD)
    Time (mean ± σ):     11.095 s ±  0.029 s    [User: 10.546 s, System: 0.521 s]
    Range (min … max):   11.037 s … 11.122 s    10 runs

  Summary
    git -c core.abbrev=9000 log --abbrev-commit HEAD (revision = HEAD) ran
      1.15 ± 0.00 times faster than git -c core.abbrev=9000 log --abbrev-commit HEAD (revision = HEAD~)

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-12 12:57:18 -07:00
59ff92c516 parse-options-cb: stop clamping "--abbrev=" to hash length
The `OPT__ABBREV()` option allows the user to specify the length that
object hashes shall be abbreviated to. This length needs to be in the
range of `(MIN_ABBREV, the_hash_algo->hexsz)`, which is why we clamp the
value as required. While this makes sense in the case of `MIN_ABBREV`,
it is unnecessary for the upper boundary as the value is eventually
passed down to `repo_find_unnique_abbrev_r()`, which handles values
larger than the current hash length just fine.

In the preceding commit, we have changed parsing of the "core.abbrev"
config to stop clamping to the upper boundary. Let's do the same here so
that the code becomes simpler, we are consistent with how we treat the
"core.abbrev" config and so that we stop depending on `the_repository`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-12 12:57:18 -07:00
524c0183c9 config: fix segfault when parsing "core.abbrev" without repo
The "core.abbrev" config allows the user to specify the minimum length
when abbreviating object hashes. Next to the values "auto" and "no",
this config also accepts a concrete length that needs to be bigger or
equal to the minimum length and smaller or equal to the hash algorithm's
hex length. While the former condition is trivial, the latter depends on
the object format used by the current repository. It is thus a variable
upper boundary that may either be 40 (SHA-1) or 64 (SHA-256).

This has two major downsides. First, the user that specifies this config
must be aware of the object hashes that its repository use. If they want
to configure the value globally, then they cannot pick any value in the
range `[41, 64]` if they have any repository that uses SHA-1. If they
did, Git would error out when parsing the config.

Second, and more importantly, parsing "core.abbrev" crashes when outside
of a Git repository because we dereference `the_hash_algo` to figure out
its hex length. Starting with c8aed5e8da (repository: stop setting SHA1
as the default object hash, 2024-05-07) though, we stopped initializing
`the_hash_algo` outside of Git repositories.

Fix both of these issues by not making it an error anymore when the
given length exceeds the hash length. Instead, leave the abbreviated
length intact. `repo_find_unique_abbrev_r()` handles this just fine
except for a performance penalty which we will fix in a subsequent
commit.

Reported-by: Kyle Lippincott <spectral@google.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-12 12:57:18 -07:00
1d969afb78 Makefile: add ability to append to CFLAGS and LDFLAGS
There are some usecases where we may want to append CFLAGS to the
default CFLAGS set by Git. This could for example be to enable or
disable specific compiler warnings or to change the optimization level
that code is compiled with. This cannot be done without overriding the
complete CFLAGS value though and thus requires the user to redeclare the
complete defaults used by Git.

Introduce a new variable `CFLAGS_APPEND` that gets appended to the
default value of `CFLAGS`. As compiler options are last-one-wins, this
fulfills both of the usecases mentioned above. It's also common practice
across many other projects to have such a variable.

While at it, also introduce a matching `LDFLAGS_APPEND` variable. While
there isn't really any need for this variable as there are no default
`LDFLAGS`, users may expect this variable to exist, as well.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 16:11:43 -07:00
e162aed591 pack-revindex.c: guard against out-of-bounds pack lookups
The function midx_key_to_pack_pos() is a helper function used by
midx_to_pack_pos() and midx_pair_to_pack_pos() to translate a (pack,
offset) tuple into a position into the MIDX pseudo-pack order.

Ensure that the pack ID given to midx_pair_to_pack_pos() is bounded by
the number of packs within the MIDX to prevent, for instance,
uninitialized memory from being used as a pack ID.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 16:08:28 -07:00
ed4a1d6ae1 pack-bitmap.c: avoid uninitialized pack_int_id during reuse
When performing multi-pack reuse, reuse_partial_packfile_from_bitmap()
is responsible for generating an array of bitmapped_pack structs from
which to perform reuse.

In the multi-pack case, we loop over the MIDXs packs and copy the result
of calling `nth_bitmapped_pack()` to construct the list of reusable
paths.

But we may also want to do pack-reuse over a single pack, either because
we only had one pack to perform reuse over (in the case of single-pack
bitmaps), or because we explicitly asked to do single pack reuse even
with a MIDX[^1].

When this is the case, the array we generate of reusable packs contains
only a single element, which is either (a) the pack attached to the
single-pack bitmap, or (b) the MIDX's preferred pack.

In 795006fff4 (pack-bitmap: gracefully handle missing BTMP chunks,
2024-04-15), we refactored the reuse_partial_packfile_from_bitmap()
function and stopped assigning the pack_int_id field when reusing only
the MIDX's preferred pack. This results in an uninitialized read down in
try_partial_reuse() like so:

    ==7474==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x55c5cd191dde in try_partial_reuse pack-bitmap.c:1887:8
    #1 0x55c5cd191dde in reuse_partial_packfile_from_bitmap_1 pack-bitmap.c:2001:8
    #2 0x55c5cd191dde in reuse_partial_packfile_from_bitmap pack-bitmap.c:2105:3
    #3 0x55c5cce0bd0e in get_object_list_from_bitmap builtin/pack-objects.c:4043:3
    #4 0x55c5cce0bd0e in get_object_list builtin/pack-objects.c:4156:27
    #5 0x55c5cce0bd0e in cmd_pack_objects builtin/pack-objects.c:4596:3
    #6 0x55c5ccc8fac8 in run_builtin git.c:474:11

which happens when try_partial_reuse() tries to call
midx_pair_to_pack_pos() when it tries to reject cross-pack deltas.

Avoid the uninitialized read by ensuring that the pack_int_id field is
set in the single-pack reuse case by setting it to either the MIDX
preferred pack's pack_int_id, or '-1', in the case of single-pack
bitmaps.  In the latter case, we never read the pack_int_id field, so
the choice of '-1' is intentional as a "garbage in, garbage out"
measure.

Guard against further regressions in this area by adding a test which
ensures that we do not throw out deltas from the preferred pack as
"cross-pack" due to an uninitialized pack_int_id.

[^1]: This can happen for a couple of reasons, either because the
  repository is configured with 'pack.allowPackReuse=(true|single)', or
  because the MIDX was generated prior to the introduction of the BTMP
  chunk, which contains information necessary to perform multi-pack
  reuse.

Reported-by: Kyle Lippincott <spectral@google.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 16:08:28 -07:00
0c5a62f14b midx-write.c: do not read existing MIDX with packs_to_include
Commit d6a8c58675 (midx-write.c: support reading an existing MIDX with
`packs_to_include`, 2024-05-29) changed the MIDX generation machinery to
support reading from an existing MIDX when writing a new one.

Unfortunately, the rest of the MIDX generation machinery is not prepared
to deal with such a change. For instance, the function responsible for
adding to the object ID fanout table from a MIDX source
(midx_fanout_add_midx_fanout()) will gladly add objects from an existing
MIDX for some fanout level regardless of whether or not those objects
came from packs that are to be included in the subsequent MIDX write.

This results in broken pseudo-pack object order (leading to incorrect
object traversal results) and segmentation faults, like so (generated by
running the added test prior to the changes in midx-write.c):

    #0  0x000055ee31393f47 in midx_pack_order (ctx=0x7ffdde205c70) at midx-write.c:590
    #1  0x000055ee31395a69 in write_midx_internal (object_dir=0x55ee32570440 ".git/objects",
        packs_to_include=0x7ffdde205e20, packs_to_drop=0x0, preferred_pack_name=0x0,
        refs_snapshot=0x0, flags=15) at midx-write.c:1171
    #2  0x000055ee31395f38 in write_midx_file_only (object_dir=0x55ee32570440 ".git/objects",
        packs_to_include=0x7ffdde205e20, preferred_pack_name=0x0, refs_snapshot=0x0, flags=15)
        at midx-write.c:1274
    [...]

In stack frame #0, the code on midx-write.c:590 is using the new pack ID
corresponding to some object which was added from the existing MIDX.
Importantly, the pack from which that object was selected in the
existing MIDX does not appear in the new MIDX as it was excluded via
`--stdin-packs`.

In this instance, the pack in question had pack ID "1" in the existing
MIDX, but since it was excluded from the new MIDX, we never filled in
that entry in the pack_perm table, resulting in:

    (gdb) p *ctx->pack_perm@2
    $1 = {0, 1515870810}

Which is what causes the segfault above when we try and read:

    struct pack_info *pack = &ctx->info[ctx->pack_perm[i]];
    if (pack->bitmap_pos == BITMAP_POS_UNKNOWN)
        pack->bitmap_pos = 0;

Fundamentally, we should be able to read information from an existing
MIDX when generating a new one. But in practice the midx-write.c code
assumes that we won't run into issues like the above with incongruent
pack IDs, and often makes those assumptions in extremely subtle and
fragile ways.

Instead, let's avoid reading from an existing MIDX altogether, and stick
with the pre-d6a8c58675 implementation. Harden against any regressions
in this area by adding a test which demonstrates these issues.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 16:08:28 -07:00
fbf7a46d88 builtin/blame: fix leaking ignore revs files
When parsing the blame configuration we add "blame.ignoreRevsFile"
configs to a string list. This string list is declared as with `NODUP`,
and thus we hand over the allocated string to that list. We eventually
end up calling `string_list_clear()` on that list, but due to it being
declared as `NODUP` we will not release the associated strings and thus
leak memory.

Fix this issue by setting up the list as `DUP` instead and free the
config string after insertion.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:08 -07:00
3332f35577 builtin/blame: fix leaking prefixed paths
In `cmd_blame()` we compute prefixed paths by calling `add_prefix()`,
which itself calls `prefix_path()`. While `prefix_path()` returns an
allocated string, `add_prefix()` pretends to return a constant string.
Consequently, this path never gets freed.

Fix the return type to be `char *` and free the path to plug the memory
leak.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:08 -07:00
ee6a998583 blame: fix leaking data for blame scoreboards
There are some memory leaks when cleaning up blame scoreboards. Fix
those.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:08 -07:00
4b4f5a911c line-range: plug leaking find functions
In `parse_range_funcname()` we may end up allocating a "find function",
but never free it. Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:08 -07:00
44ec7c575f merge: fix leaking merge bases
When calling either the recursive or the ORT merge machineries we need
to provide a list of merge bases. The ownership of that parameter is
then implicitly transferred to the callee, which is somewhat fishy.
Furthermore, that list may leak in some cases where the merge machinery
runs into an error, thus causing a memory leak.

Refactor the code such that we stop transferring ownership. Instead, the
merge machinery will now create its own local copies of the passed in
list as required if they need to modify the list. Free the list at the
callsites as required.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:08 -07:00
77241a6b5e builtin/merge: fix leaking struct cmdnames in get_strategy()
In "builtin/merge.c" we use the helper infrastructure to figure out what
merge strategies there are. We never free contents of the `cmdnames`
structures though and thus leak their memory.

Fix this by exposing the already existing `clean_cmdnames()` function to
release their memory. As this name isn't quite idiomatic, rename it to
`cmdnames_release()` while at it.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:07 -07:00
6e95f4ee03 sequencer: fix memory leaks in make_script_with_merges()
Fix some trivial memory leaks in `make_script_with_merges()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:07 -07:00
8909d6e1a1 builtin/clone: plug leaking HEAD ref in wanted_peer_refs()
In `wanted_peer_refs()` we first create a copy of the "HEAD" ref. This
copy may not actually be passed back to the caller, but is not getting
freed in this case. Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:07 -07:00
4806c55c86 apply: fix leaking string in match_fragment()
Before calling `update_pre_post_images()`, we call `strbuf_detach()` to
put its buffer into a new string variable that we then pass to that
function. Besides being rather pointless, it also causes us to leak
memory of that variable because we never free it.

Get rid of the variable altogether and instead reach into the `strbuf`
directly. While at it, refactor the code to have a common exit path and
mark string that do not contain allocated memory as constant.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:07 -07:00
1e5c1601f9 sequencer: fix leaking string buffer in commit_staged_changes()
We're leaking the `rev` string buffer in various call paths. Refactor
the function to have a common exit path so that we can release its
memory reliably.

This fixes a subset of tests failing with the memory sanitizer in t3404.
But as there are more failures, we cannot yet mark the whole test suite
as passing.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:07 -07:00
63c9bd372e commit: fix leaking parents when calling commit_tree_extended()
When creating commits via `commit_tree_extended()`, the caller passes in
a string list of parents. This call implicitly transfers ownership of
that list to the function, which is quite surprising to begin with. But
to make matters worse, `commit_tree_extended()` doesn't even bother to
free the list of parents in error cases. The result is a memory leak,
and one that the caller cannot fix by themselves because they do not
know whether parts of the string list have already been released.

Refactor the code such that callers can keep ownership of the list of
parents, which is getting indicated by parameter being a constant
pointer now. Free the lists at the calling site and add a common exit
path to those sites as required.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:07 -07:00
c6eb58bfb1 config: fix leaking "core.notesref" variable
The variable used to track the "core.notesref" config is not getting
freed before we assign to it and thus leaks. Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:07 -07:00
f46ede661f rerere: fix various trivial leaks
We leak various different string lists in the rerere code. Free those to
plug them.

Note that the `merge_rr` variable is intentionally being free'd with the
`free_util` parameter set to 1. The `util` field is used there to store
the IDs of every rerere item and thus needs to be freed, as well.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:06 -07:00
748bd0943b builtin/stash: fix leak in show_stash()
We leak the `revision_args()` variable. Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:06 -07:00
a90a089611 revision: free diff options
There is a todo comment in `release_revisions()` that mentions that we
need to free the diff options, which was added via 54c8a7c379 (revisions
API: add a TODO for diff_free(&revs->diffopt), 2022-04-14). Releasing
the diff options wasn't quite feasible at that time because some call
sites rely on its contents to remain even after the revisions have been
released.

In fact, there really only are a couple of callsites that misbehave
here:

  - `cmd_shortlog()` releases the revisions, but continues to access its
    file pointer.

  - `do_diff_cache()` creates a shallow copy of `struct diff_options`,
    but does not set the `no_free` member. Consequently, we end up
    releasing resources of the caller-provided diff options.

  - `diff_free()` and friends do not play nice when being called
    multiple times as they don't unset data structures that they have
    just released.

Fix all of those cases and enable the call to `diff_free()`, which plugs
a bunch of memory leaks.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:06 -07:00
a282dbeba7 builtin/log: fix leaking commit list in git-cherry(1)
We're storing the list of commits that git-cherry(1) is about to print
into a temporary list. This list is never getting free'd and thus leaks.
Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:06 -07:00
8ff6bd4750 merge-recursive: fix memory leak when finalizing merge
We do not free some members of `struct merge_options`' private data.
Fix this to plug those leaks.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:06 -07:00
3199b22e7d builtin/merge-recursive: fix leaking object ID bases
In `cmd_merge_recursive()` we have a static array of object ID bases
that we pass to `merge_recursive_generic()`. This interface is somewhat
weird though because the latter function accepts a pointer to a pointer
of object IDs, which requires us to allocate the object IDs on the heap.
And as we never free those object IDs, the end result is a leak.

While we can easily solve this leak by just freeing the respective
object IDs, the whole calling convention is somewhat weird. Instead,
refactor `merge_recursive_generic()` to accept a plain pointer to object
IDs so that we can avoid allocating them altogether.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:06 -07:00
9e903a5531 builtin/difftool: plug memory leaks in run_dir_diff()
We're leaking a bunch of memory leaks in `run_dir_diff()`. Plug them.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:06 -07:00
f87c55c264 object-name: free leaking object contexts
While it is documented in `struct object_context::path` that this
variable needs to be released by the caller, this fact is rather easy to
miss given that we do not ever provide a function to release the object
context. And of course, while some callers dutifully release the path,
many others don't.

Introduce a new `object_context_release()` function that releases the
path. Convert callsites that used to free the path to use that new
function and add missing calls to callsites that were leaking memory.
Refactor those callsites as required to have a single return path, only.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:05 -07:00
61f8bb1ec1 builtin/rev-list: fix leaking bitmap index when calculating disk usage
git-rev-list(1) can speed up its object size calculations for reachable
objects via a bitmap walk, if there is any bitmap. This is done in
`try_bitmap_disk_usage()`, which tries to optimistically load the bitmap
and then use it, if available. It never frees it though, leading to a
memory leak. Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:05 -07:00