On Wed, Jul 07 2021, Han-Wen Nienhuys via GitGitGadget wrote:
> /*
> * Locks a ref returning the lock on success and NULL on failure.
> - * On failure errno is set to something meaningful.
> */
> static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
> const char *refname,
> @@ -922,7 +921,6 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
> {
> struct strbuf ref_file = STRBUF_INIT;
> struct ref_lock *lock;
> - int last_errno = 0;
> int mustexist = (old_oid && !is_null_oid(old_oid));
> int resolve_flags = RESOLVE_REF_NO_RECURSE;
> int resolved;
> @@ -949,7 +947,6 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
> * to remain.
> */
> if (remove_empty_directories(&ref_file)) {
> - last_errno = errno;
> if (!refs_verify_refname_available(
> &refs->base,
> refname, extras, skip, err))
> @@ -962,10 +959,13 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
> &lock->old_oid, type);
> }
> if (!resolved) {
> - last_errno = errno;
> + int last_errno = errno;
> if (last_errno != ENOTDIR ||
> - !refs_verify_refname_available(&refs->base, refname,
> - extras, skip, err))
> + /* in case of D/F conflict, try to generate a better error
> + * message. If that fails, fall back to strerror(ENOTDIR).
> + */
> + !refs_verify_refname_available(&refs->base, refname, extras,
> + skip, err))
> strbuf_addf(err, "unable to resolve reference '%s': %s",
> refname, strerror(last_errno));
I don't think it's some dealbreaker and we can move on, but just FWIW I
think what I mentioned ending in your
https://lore.kernel.org/git/CAFQ2z_NpyJQLuM70MhJ8K1h2v3QXFuAZRjN=SvSsjnukNRJ8pw@xxxxxxxxxxxxxx/
is still outstanding.
I.e. you added the comment, which is just says what the error emitting
looks like, that's all well & good.
But what I was pointing out that it didn't make sense to do any
"last_errno" here at all anymore. You pointed to 5b2d8d6f218
(lock_ref_sha1_basic(): improve diagnostics for ref D/F conflicts,
2015-05-11), we started setting "last_errno" there, but that was *not*
to avoid clobbering between the !resolved and the
strbuf_add(strerror(last_errno)) here, but rather to carry the
"last_errno" forward to the end of this lock_ref_oid_basic(), because
other things (after this hunk) might reset/clear errno.
Anyway, as noted there it doesn't actually matter, just reviewing &
looking if there's any loose ends, and for future source spelunking for
anyone reading this thread.
I.e. something like what I mentioned in
https://lore.kernel.org/git/87k0mae0ga.fsf@xxxxxxxxxxxxxxxxxxx/ could be
squashed in, or better yet (probably) this:
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 83ddfb3b627..f0ce0aac857 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -958,17 +958,15 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
refname, resolve_flags,
&lock->old_oid, type);
}
- if (!resolved) {
- int last_errno = errno;
- if (last_errno != ENOTDIR ||
- /* in case of D/F conflict, try to generate a better error
- * message. If that fails, fall back to strerror(ENOTDIR).
- */
- !refs_verify_refname_available(&refs->base, refname, extras,
- skip, err))
- strbuf_addf(err, "unable to resolve reference '%s': %s",
- refname, strerror(last_errno));
-
+ if (!resolved &&
+ (errno != ENOTDIR ||
+ /* in case of D/F conflict, try to generate a better error
+ * message. If that fails, fall back to strerror(ENOTDIR).
+ */
+ !refs_verify_refname_available(&refs->base, refname, extras,
+ skip, err))) {
+ strbuf_addf(err, "unable to resolve reference '%s': %s",
+ refname, strerror(errno));
goto error_return;
}
