git/cache-tree.c, branch v2.50.0

treewide: convert users of `repo_has_object_file()` to `has_object()`

2025-04-29T17:08:13Z

As the comment of `repo_has_object_file()` and its `_with_flags()` variant tells us, these functions are considered to be deprecated in favor of `has_object()`. There are a couple of slight benefits in favor of the replacement: - The new function has a short-and-sweet name. - More explicit defaults: `has_object()` doesn't fetch missing objects via promisor remotes, and neither does it reload packfiles if an object wasn't found by default. This ensures that it becomes immediately obvious when a simple object existence check may result in expensive actions. Most importantly though, it is confusing that we have two sets of functions that ultimately do the same thing, but with different defaults. Start sunsetting `repo_has_object_file()` and its `_with_flags()` sibling by replacing all callsites with `has_object()`: - `repo_has_object_file(...)` is equivalent to `has_object(..., HAS_OBJECT_RECHECK_PACKED | HAS_OBJECT_FETCH_PROMISOR)`. - `repo_has_object_file_with_flags(..., OBJECT_INFO_QUICK | OBJECT_INFO_SKIP_FETCH_OBJECT)` is equivalent to `has_object(..., 0)`. - `repo_has_object_file_with_flags(..., OBJECT_INFO_SKIP_FETCH_OBJECT)` is equivalent to `has_object(..., HAS_OBJECT_RECHECK_PACKED)`. - `repo_has_object_file_with_flags(..., OBJECT_INFO_QUICK)` is equivalent to `has_object(..., HAS_OBJECT_FETCH_PROMISOR)`. The replacements should be functionally equivalent. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

object-store: merge "object-store-ll.h" and "object-store.h"

2025-04-15T15:24:37Z

The "object-store-ll.h" header has been introduced to keep transitive header dependendcies and compile times at bay. Now that we have created a new "object-store.c" file though we can easily move the last remaining additional bit of "object-store.h", the `odb_path_map`, out of the header. Do so. As the "object-store.h" header is now equivalent to its low-level alternative we drop the latter and inline it into the former. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

object-file: split up concerns of `HASH_*` flags

2025-04-15T15:24:36Z

The functions `hash_object_file()`, `write_object_file()` and `index_fd()` reuse the same set of flags to alter their behaviour. This not only adds confusion, but given that every function only supports a subset of the flags it becomes very hard to see which flags can be passed to what function. Last but not least, this entangles the implementation of all three function families. Split up concerns by creating separate flags for each of the function families. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

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

Merge branch 'ps/cache-tree-w-broken-index-entry'

2024-10-22T18:40:38Z

Fail gracefully instead of crashing when attempting to write the contents of a corrupt in-core index as a tree object. * ps/cache-tree-w-broken-index-entry: unpack-trees: detect mismatching number of cache-tree/index entries cache-tree: detect mismatching number of index entries cache-tree: refactor verification to return error codes

cache-tree: detect mismatching number of index entries

2024-10-07T22:08:11Z

In t4058 we have some tests that exercise git-read-tree(1) when used with a tree that contains duplicate entries. While the expectation is that we fail, we ideally should fail gracefully without a segfault. But that is not the case: we never check that the number of entries in the cache-tree is less than or equal to the number of entries in the index. This can lead to an out-of-bounds read as we unconditionally access `istate->cache[idx]`, where `idx` is controlled by the number of cache-tree entries and the current position therein. The result is a segfault. Fix this segfault by adding a sanity check for the number of index entries before dereferencing them. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

cache-tree: refactor verification to return error codes

2024-10-07T22:08:11Z

The function `cache_tree_verify()` will `BUG()` whenever it finds that the cache-tree extension of the index is corrupt. The function is thus inherently untestable because the resulting call to `abort()` will be detected by our testing framework and labelled an error. And rightfully so: it shouldn't ever be possible to hit bugs, as they should indicate a programming error rather than corruption of on-disk state. Refactor the function to instead return error codes. This also ensures that the function can be used e.g. by git-fsck(1) without the whole process dying. Furthermore, this refactoring plugs some memory leaks when returning early by creating a common exit path. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

environment: make `get_git_dir()` accept a repository

2024-09-12T17:15:39Z

The `get_git_dir()` function retrieves the path to the Git directory for `the_repository`. Make it accept a `struct repository` such that it can work on arbitrary repositories and make it part of the repository subsystem. This reduces our reliance on `the_repository` and clarifies scope. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

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 `is_empty_{blob,tree}_oid()`

2024-06-14T17:26:33Z

Both functions `is_empty_{blob,tree}_oid()` 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