git/reftable, branch v2.52.0

Merge branch 'kn/reftable-consistency-checks'

2025-10-14T05:00:35Z

The reftable backend learned to sanity check its on-disk data more carefully. * kn/reftable-consistency-checks: refs/reftable: add fsck check for checking the table name reftable: add code to facilitate consistency checks fsck: order 'fsck_msg_type' alphabetically Documentation/fsck-msgids: remove duplicate msg id reftable: check for trailing newline in 'tables.list' refs: move consistency check msg to generic layer refs: remove unused headers

reftable: add code to facilitate consistency checks

2025-10-07T16:22:58Z

The `git refs verify` command is used to run consistency checks on the reference backends. This command is also invoked when users run 'git fsck'. While the files-backend has some fsck checks added, the reftable backend lacks such checks. Let's add the required infrastructure and a check to test for the files present in the reftable directory. Since the reftable library is treated as an independent library we should ensure that the library code works independently without knowledge about Git's internals. To do this, add both 'reftable/fsck.c' and 'reftable/reftable-fsck.h'. Which provide an entry point 'reftable_fsck_check' for running fsck checks over a provided reftable stack. The callee provides the function with callbacks to handle issue and information reporting. The added check, goes over all tables in the reftable stack validates that they have a valid name. It not, it raises an error. While here, move 'reftable/error.o' in the Makefile to retain lexicographic ordering. Signed-off-by: Karthik Nayak Signed-off-by: Junio C Hamano

reftable: check for trailing newline in 'tables.list'

2025-10-07T16:22:57Z

In the reftable format, the 'tables.list' file contains a newline separated list of tables. While we parse this file, we do not check or care about the last newline. Tighten the parser in `parse_names()` to return an appropriate error if the last newline is missing. This requires modification to `parse_names()` to now return the error while accepting the output as a third argument. Signed-off-by: Karthik Nayak Signed-off-by: Junio C Hamano

reftable: don't second-guess errors from flock interface

2025-08-12T14:41:00Z

The `flock` interface is implemented as part of "reftable/system.c" and thus needs to be implemented by the integrator between the reftable library and its parent code base. As such, we cannot rely on any specific implementation thereof. Regardless of that, users of the `flock` subsystem rely on `errno` being set to specific values. This is fragile and not documented anywhere and doesn't really make for a good interface. Refactor the code so that the implementations themselves are expected to return reftable-specific error codes. Our implementation of the `flock` subsystem already knows to do this for all error paths except one. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

reftable/stack: handle outdated stacks when compacting

2025-08-12T14:41:00Z

When we compact the reftable stack we first acquire the lock for the "tables.list" file and then reload the stack to check that it is still up-to-date. This is done by calling `stack_uptodate()`, which knows to return zero in case the stack is up-to-date, a positive value if it is not and a negative error code on unexpected conditions. We don't do proper error checking though, but instead we only check whether the returned error code is non-zero. If so, we simply bubble it up the calling stack, which means that callers may see an unexpected positive value. Fix this issue by translating to `REFTABLE_OUTDATED_ERROR` instead. Handle this situation in `reftable_addition_commit()`, where we perform a best-effort auto-compaction. All other callsites of `stack_uptodate()` know to handle a positive return value and thus don't need to be fixed. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

reftable/stack: allow passing flags to `reftable_stack_add()`

2025-08-12T14:40:59Z

The `reftable_stack_add()` function is a simple wrapper to lock the stack, add records to it via a callback and then commit the result. One problem with it though is that it doesn't accept any flags for creating the addition. This makes it impossible to automatically reload the stack in case it was modified before we managed to lock the stack. Add a `flags` field to plug this gap and pass it through accordingly. For now this new flag won't be used by us, but it will be used by libgit2. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

reftable/stack: fix compiler warning due to missing braces

2025-08-12T14:40:59Z

While perfectly legal, older compiler toolchains complain when zero-initializing structs that contain nested structs with `{0}`: /home/libgit2/source/deps/reftable/stack.c:862:35: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces] struct reftable_addition empty = REFTABLE_ADDITION_INIT; ^~~~~~~~~~~~~~~~~~~~~~ /home/libgit2/source/deps/reftable/stack.c:707:33: note: expanded from macro 'REFTABLE_ADDITION_INIT' #define REFTABLE_ADDITION_INIT {0} ^ We had the discussion around whether or not we want to handle such bogus compiler errors in the past already [1]. Back then we basically decided that we do not care about such old-and-buggy compilers, so while we could fix the issue by using `{{0}}` instead this is not the preferred way to handle this in the Git codebase. We have an easier fix though: we can just drop the macro altogether and handle initialization of the struct in `reftable_stack_addition_init()`. Callers are expected to call this function already, so this change even simplifies the calling convention. [1]: https://lore.kernel.org/git/20220710081135.74964-1-sunshine@sunshineco.com/T/ Suggested-by: Carlo Arenas Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

reftable/stack: reorder code to avoid forward declarations

2025-08-12T14:40:59Z

We have a couple of forward declarations in the stack-related code of the reftable library. These declarations aren't really required, but are simply caused by unfortunate ordering. Reorder the code and remove the forward declarations. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

reftable/writer: drop Git-specific `QSORT()` macro

2025-08-12T14:40:59Z

The reftable writer accidentally uses the Git-specific `QSORT()` macro. This macro removes the need for the caller to provide the element size, but other than that it's mostly equivalent to `qsort()`. Replace the macro accordingly to make the library usable outside of Git. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

reftable/writer: fix type used for number of records

2025-08-12T14:40:58Z

Both `reftable_writer_add_refs()` and `reftable_writer_add_logs()` accept an array of records that should be added to the new table. Callers of this function are expected to also pass the number of such records to the function to tell it how many such records it is supposed to write. But while all callers pass in a `size_t`, which is a sensible choice, the function in fact accepts an `int` as argument, which is less so. Fix this. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano