From: Han-Wen Nienhuys <hanwen@xxxxxxxxxx>
refs/files-backend.c::lock_ref_oid_basic() tries to signal how it failed
to its callers using errno.
It is safe to stop setting errno here, because the callers of this
file-scope static function are
* files_copy_or_rename_ref()
* files_create_symref()
* files_reflog_expire()
None of them looks at errno after seeing a negative return from
lock_ref_oid_basic() to make any decision, and no caller of these three
functions looks at errno after they signal a failure by returning a
negative value. In particular,
* files_copy_or_rename_ref() - here, calls are followed by error()
(which performs I/O) or write_ref_to_lockfile() (which calls
parse_object() which may perform I/O)
* files_create_symref() - here, calls are followed by error() or
create_symref_locked() (which performs I/O and does not inspect
errno)
* files_reflog_expire() - here, calls are followed by error() or
refs_reflog_exists() (which calls a function in a vtable that is not
documented to use and/or preserve errno)
In the case of the "errno != ENOTDIR" case that originates in 5b2d8d6f218
(lock_ref_sha1_basic(): improve diagnostics for ref D/F conflicts,
2015-05-11), there the "last_errno" was saved away to return it from
lock_ref_oid_basic(), now that we're no longer doing that we can skip
that entirely and use "errno" directly. A follow-up change will
extract the specific errno we want earlier in this function.
Signed-off-by: Han-Wen Nienhuys <hanwen@xxxxxxxxxx>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
refs/files-backend.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 7e4963fd07..45f198c3fc 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -910,7 +910,6 @@ static int create_reflock(const char *path, void *cb)
/*
* 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;
@@ -941,13 +939,15 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
resolved = !!refs_resolve_ref_unsafe(&refs->base,
refname, resolve_flags,
&lock->old_oid, type);
- if (!resolved) {
- last_errno = errno;
- if (last_errno != 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;
}
@@ -961,20 +961,17 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
if (is_null_oid(&lock->old_oid) &&
refs_verify_refname_available(refs->packed_ref_store, refname,
extras, skip, err)) {
- last_errno = ENOTDIR;
goto error_return;
}
lock->ref_name = xstrdup(refname);
if (raceproof_create_file(ref_file.buf, create_reflock, &lock->lk)) {
- last_errno = errno;
unable_to_lock_message(ref_file.buf, errno, err);
goto error_return;
}
if (verify_lock(&refs->base, lock, old_oid, mustexist, err)) {
- last_errno = errno;
goto error_return;
}
goto out;
@@ -985,7 +982,6 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
out:
strbuf_release(&ref_file);
- errno = last_errno;
return lock;
}
--
2.32.0.851.g0fc62a9785
