git/diff-lib.c, branch v2.48.2

global: mark code units that generate warnings with `-Wsign-compare`

2024-12-06T11:20:02Z

Mark code units that generate warnings with `-Wsign-compare`. This allows for a structured approach to get rid of all such warnings over time in a way that can be easily measured. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

diff-lib: fix leaking diffopts in `do_diff_cache()`

2024-11-05T06:37:52Z

In `do_diff_cache()` we initialize a new `rev_info` and then overwrite its `diffopt` with a user-provided set of options. This can leak memory because `repo_init_revisions()` may end up allocating memory for the `diffopt` itself depending on the configuration. And since that field is overwritten we won't ever free it. Plug the memory leak by releasing the diffopts before we overwrite them. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

Merge branch 'jk/output-prefix-cleanup'

2024-10-10T21:22:30Z

Code clean-up. * jk/output-prefix-cleanup: diff: store graph prefix buf in git_graph struct diff: return line_prefix directly when possible diff: return const char from output_prefix callback diff: drop line_prefix_length field line-log: use diff_line_prefix() instead of custom helper

diff: return const char from output_prefix callback

2024-10-03T21:22:22Z

The diff_options structure has an output_prefix callback for returning a prefix string, but it does so by returning a pointer to a strbuf. This makes the interface awkward. There's no reason the callback should need to use a strbuf, and it creates questions about whether the ownership of the resulting buffer should be transferred to the caller (it should not be, but a recent attempt to clean up this code led to a double-free in some cases). The one advantage we get is that the strbuf contains a ptr/len pair, so we could in theory have a prefix with embedded NULs. But we can observe that none of the existing callbacks would ever produce such a NUL (they are usually just indentation or graph symbols, and even the "--line-prefix" option takes a NUL-terminated string). And anyway, only one caller (the one in log_tree_diff_flush) actually looks at the strbuf length. In every other case we use a helper function which discards the length and just returns the NUL-terminated string. So let's just have the callback return a "const char *" pointer. It's up to the callbacks themselves if they want to use a strbuf under the hood. And now the caller in log_tree_diff_flush() can just use the helper function along with everybody else. That lets us even simplify out the function pointer check, since the helper returns an empty string (technically this does mean we'll sometimes issue an empty fputs() call, but I don't think this code path is hot enough to care about that). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

diff-lib: drop unused index argument from get_stat_data()

2024-08-17T16:44:41Z

The "struct index_state" parameter passed to get_stat_data() has been unused since we stopped passing it to check_removed() in 6a044a2048 (diff-lib: fix check_removed when fsmonitor is on, 2023-09-11). We can just drop it, which in turns lets us simplify our callers a bit. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'ps/leakfixes-more'

2024-07-08T21:53:10Z

More memory leaks have been plugged. * ps/leakfixes-more: (29 commits) builtin/blame: fix leaking ignore revs files builtin/blame: fix leaking prefixed paths blame: fix leaking data for blame scoreboards line-range: plug leaking find functions merge: fix leaking merge bases builtin/merge: fix leaking `struct cmdnames` in `get_strategy()` sequencer: fix memory leaks in `make_script_with_merges()` builtin/clone: plug leaking HEAD ref in `wanted_peer_refs()` apply: fix leaking string in `match_fragment()` sequencer: fix leaking string buffer in `commit_staged_changes()` commit: fix leaking parents when calling `commit_tree_extended()` config: fix leaking "core.notesref" variable rerere: fix various trivial leaks builtin/stash: fix leak in `show_stash()` revision: free diff options builtin/log: fix leaking commit list in git-cherry(1) merge-recursive: fix memory leak when finalizing merge builtin/merge-recursive: fix leaking object ID bases builtin/difftool: plug memory leaks in `run_dir_diff()` object-name: free leaking object contexts ...

global: introduce `USE_THE_REPOSITORY_VARIABLE` macro

2024-06-14T17:26:33Z

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 Signed-off-by: Junio C Hamano

hash: require hash algorithm in `oidread()` and `oidclr()`

2024-06-14T17:26:32Z

Both `oidread()` and `oidclr()` use `the_repository` to derive the hash function that shall be used. Require callers to pass in the hash algorithm to get rid of this implicit dependency. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

revision: free diff options

2024-06-11T20:15:06Z

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 Signed-off-by: Junio C Hamano

refs: refactor `resolve_gitlink_ref()` to accept a repository

2024-05-17T17:33:38Z

In `resolve_gitlink_ref()` we implicitly rely on `the_repository` to look up the submodule ref store. Now that we can look up submodule ref stores for arbitrary repositories we can improve this function to instead accept a repository as parameter for which we want to resolve the gitlink. Do so and adjust callers accordingly. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano