git/refs, branch v2.53.0

refs/reftable: introduce generic checks for refs

2026-01-12T14:55:41Z

In a preceding commit we have extracted generic checks for both direct and symbolic refs that apply for all backends. Wire up those checks for the "reftable" backend. Note that this is done by iterating through all refs manually with the low-level reftable ref iterator. We explicitly don't want to use the higher-level iterator that is exposed to users of the reftable backend as that iterator may swallow for example broken refs. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/reftable: fix consistency checks with worktrees

2026-01-12T14:55:41Z

The ref consistency checks are driven via `cmd_refs_verify()`. That function loops through all worktrees (including the main worktree) and then checks the ref store for each of them individually. It follows that the backend is expected to only verify refs that belong to the specified worktree. While the "files" backend handles this correctly, the "reftable" backend doesn't. In fact, it completely ignores the passed worktree and instead verifies refs of _all_ worktrees. The consequence is that we'll end up every ref store N times, where N is the number of worktrees. Or rather, that would be the case if we actually iterated through the worktree reftable stacks correctly. But we use `strmap_for_each_entry()` to iterate through the stacks, but the map is in fact not even properly populated. So instead of checking stacks N^2 times, we actually only end up checking the reftable stack of the main worktree. Fix this bug by only verifying the stack of the passed-in worktree and constructing the backends via `backend_for_worktree()`. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/reftable: extract function to retrieve backend for worktree

2026-01-12T14:55:41Z

Pull out the logic to retrieve a backend for a given worktree. This function will be used in a subsequent commit. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/reftable: adapt includes to become consistent

2026-01-12T14:55:41Z

Adapt the includes to be sorted and to use include paths that are relative to the "refs/" directory. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/files: introduce function to perform normal ref checks

2026-01-12T14:55:41Z

In a subsequent commit we'll introduce new generic checks for direct refs. These checks will be independent of the actual backend. Introduce a new function `refs_fsck_ref()` that will be used for this purpose. At the current point in time it's still empty, but it will get populated in a subsequent commit. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/files: extract generic symref target checks

2026-01-12T14:55:40Z

The consistency checks for the "files" backend contain a couple of verifications for symrefs that verify generic properties of the target reference. These properties need to hold for every backend, no matter whether it's using the "files" or "reftable" backend. Reimplementing these checks for every single backend doesn't really make sense. Extract it into a generic `refs_fsck_symref()` function that can be used by other backends, as well. The "reftable" backend will be wired up in a subsequent commit. While at it, improve the consistency checks so that we don't complain about refs pointing to a non-ref target in case the target refname format does not verify. Otherwise it's very likely that we'll generate both error messages, which feels somewhat redundant in this case. Note that the function has a couple of `UNUSED` parameters. These will become referenced in a subsequent commit. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/files: perform consistency checks for root refs

2026-01-12T14:55:40Z

While the "files" backend already knows to perform consistency checks for the "refs/" hierarchy, it doesn't verify any of its root refs. Plug this omission. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/files: improve error handling when verifying symrefs

2026-01-12T14:55:40Z

The error handling when verifying symbolic refs is a bit on the wild side: - `fsck_report_ref()` can be told to ignore specific errors. If an error has been ignored and a previous check raised an unignored error, then assigning `ret = fsck_report_ref()` will cause us to swallow the previous error. - When the target reference is not valid we bail out early without checking for other errors. Fix both of these issues by consistently or'ing the return value and not bailing out early. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/files: extract function to check single ref

2026-01-12T14:55:40Z

When checking the consistency of references we create a directory iterator and then verify each single reference in a loop. The logic to perform the actual checks is embedded into that loop, which makes it hard to reuse. But In a subsequent commit we're about to introduce a second path that wants to verify references. Prepare for this by extracting the logic to check a single reference into a standalone function. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs/files: remove useless indirection

2026-01-12T14:55:40Z

The function `files_fsck_refs()` only has a single callsite and forwards all of its arguments as-is, so it's basically a useless indirection. Inline the function call. While at it, also remove the bitwise or that we have for return values. We don't really want to or them at all, but rather just want to return an error in case either of the functions has failed. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano