Add a new refs_werrres_ref_unsafe() function, which is like
refs_resolve_ref_unsafe() except that it explicitly saves away the
"errno" to a passed-in parameter, the refs_resolve_ref_unsafe() then
becomes a wrapper for it.
In subsequent commits we'll migrate code over to it, before finally
making "refs_resolve_ref_unsafe()" with an "errno" parameter the
canonical version, so this this function exists only so that we can
incrementally migrate callers, it will be going away in a subsequent
commit.
As the added comment notes has a rather tortured name to be the same
length as "refs_resolve_ref_unsafe", to avoid churn as we won't need
to re-indent the argument lists, similarly the documentation and
structure of it in refs.h is designed to minimize a diff in a
subsequent commit, where that documentation will be added to the new
refs_resolve_ref_unsafe().
At the end of this migration the "meaningful errno" TODO item left in
76d70dc0c63 (refs.c: make resolve_ref_unsafe set errno to something
meaningful on error, 2014-06-20) will be resolved.
As can be seen from the use of refs_read_raw_ref() we'll also need to
convert some functions that the new refs_werrres_ref_unsafe() itself
calls to take this "failure_errno". That will be done in subsequent
commits.
Signed-off-by: Han-Wen Nienhuys <hanwen@xxxxxxxxxx>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
refs.c | 36 +++++++++++++++++++++++++++---------
refs.h | 12 ++++++++++++
2 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/refs.c b/refs.c
index 7f019c2377e..ad56dbb0125 100644
--- a/refs.c
+++ b/refs.c
@@ -1679,17 +1679,19 @@ int refs_read_raw_ref(struct ref_store *ref_store,
type, &errno);
}
-/* This function needs to return a meaningful errno on failure */
-const char *refs_resolve_ref_unsafe(struct ref_store *refs,
+const char *refs_werrres_ref_unsafe(struct ref_store *refs,
const char *refname,
int resolve_flags,
- struct object_id *oid, int *flags)
+ struct object_id *oid,
+ int *flags, int *failure_errno)
{
static struct strbuf sb_refname = STRBUF_INIT;
struct object_id unused_oid;
int unused_flags;
int symref_count;
+ assert(failure_errno);
+
if (!oid)
oid = &unused_oid;
if (!flags)
@@ -1700,7 +1702,7 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
!refname_is_safe(refname)) {
- errno = EINVAL;
+ *failure_errno = EINVAL;
return NULL;
}
@@ -1718,9 +1720,12 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
unsigned int read_flags = 0;
+ errno = 0;
if (refs_read_raw_ref(refs, refname,
oid, &sb_refname, &read_flags)) {
*flags |= read_flags;
+ if (errno)
+ *failure_errno = errno;
/* In reading mode, refs must eventually resolve */
if (resolve_flags & RESOLVE_REF_READING)
@@ -1731,9 +1736,9 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
* may show errors besides ENOENT if there are
* similarly-named refs.
*/
- if (errno != ENOENT &&
- errno != EISDIR &&
- errno != ENOTDIR)
+ if (*failure_errno != ENOENT &&
+ *failure_errno != EISDIR &&
+ *failure_errno != ENOTDIR)
return NULL;
oidclr(oid);
@@ -1760,7 +1765,7 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
!refname_is_safe(refname)) {
- errno = EINVAL;
+ *failure_errno = EINVAL;
return NULL;
}
@@ -1768,10 +1773,23 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
}
}
- errno = ELOOP;
+ *failure_errno = ELOOP;
return NULL;
}
+const char *refs_resolve_ref_unsafe(struct ref_store *refs, const char *refname,
+ int resolve_flags, struct object_id *oid,
+ int *flags)
+{
+ int failure_errno = 0;
+ const char *refn;
+ refn = refs_werrres_ref_unsafe(refs, refname, resolve_flags,
+ oid, flags, &failure_errno);
+ if (!refn)
+ errno = failure_errno;
+ return refn;
+}
+
/* backend functions */
int refs_init_db(struct strbuf *err)
{
diff --git a/refs.h b/refs.h
index d5099d4984e..c8afde6bb50 100644
--- a/refs.h
+++ b/refs.h
@@ -11,6 +11,18 @@ struct string_list;
struct string_list_item;
struct worktree;
+/*
+ * Callers should not inspect "errno" on failure, but rather pass in a
+ * "failure_errno" parameter, on failure the "errno" will indicate the
+ * type of failure encountered, but not necessarily one that came from
+ * a syscall. We might have faked it up.
+ */
+const char *refs_werrres_ref_unsafe(struct ref_store *refs,
+ const char *refname,
+ int resolve_flags,
+ struct object_id *oid,
+ int *flags, int *failure_errno);
+
/*
* Resolve a reference, recursively following symbolic refererences.
*
--
2.33.1.1338.g20da966911a
