Subject: [PATCH v2 6/8] refs: add failure_errno to refs_read_raw_ref() signature

From: "Han-Wen Nienhuys via GitGitGadget" <[email-masked]>
Date: Thu, 10 Jun 2021 12:57:46 +0000

From: Han-Wen Nienhuys <[email-masked]>

This makes the errno output of refs_read_raw_ref explicit.

Signed-off-by: Han-Wen Nienhuys <[email-masked]>
Reviewed-by: Jonathan Tan <[email-masked]>
---
 refs.c                | 29 ++++++++++++++---------------
 refs/files-backend.c  |  8 ++++----
 refs/packed-backend.c | 10 ++++++----
 refs/refs-internal.h  |  6 +++---
 4 files changed, 27 insertions(+), 26 deletions(-)

diff --git a/refs.c b/refs.c
index 64e2d55adcfb..ed2dde1c0c6d 100644
--- a/refs.c
+++ b/refs.c
@@ -1671,21 +1671,19 @@ static int refs_read_special_head(struct ref_store *ref_store,
 	return result;
 }
 
-int refs_read_raw_ref(struct ref_store *ref_store,
-		      const char *refname, struct object_id *oid,
-		      struct strbuf *referent, unsigned int *type)
+int refs_read_raw_ref(struct ref_store *ref_store, const char *refname,
+		      struct object_id *oid, struct strbuf *referent,
+		      unsigned int *type, int *failure_errno)
 {
-	int result, failure;
+	if (failure_errno)
+		*failure_errno = 0;
 	if (!strcmp(refname, "FETCH_HEAD") || !strcmp(refname, "MERGE_HEAD")) {
 		return refs_read_special_head(ref_store, refname, oid, referent,
 					      type);
 	}
 
-	failure = 0;
-	result = ref_store->be->read_raw_ref(ref_store, refname, oid, referent,
-					     type, &failure);
-	errno = failure;
-	return result;
+	return ref_store->be->read_raw_ref(ref_store, refname, oid, referent,
+					   type, failure_errno);
 }
 
 /* This function needs to return a meaningful errno on failure */
@@ -1726,9 +1724,10 @@ 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;
+		int read_failure = 0;
 
-		if (refs_read_raw_ref(refs, refname,
-				      oid, &sb_refname, &read_flags)) {
+		if (refs_read_raw_ref(refs, refname, oid, &sb_refname,
+				      &read_flags, &read_failure)) {
 			*flags |= read_flags;
 
 			/* In reading mode, refs must eventually resolve */
@@ -1740,9 +1739,8 @@ 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 (read_failure != ENOENT && read_failure != EISDIR &&
+			    read_failure != ENOTDIR)
 				return NULL;
 
 			oidclr(oid);
@@ -2254,7 +2252,8 @@ int refs_verify_refname_available(struct ref_store *refs,
 		if (skip && string_list_has_string(skip, dirname.buf))
 			continue;
 
-		if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
+		if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent,
+				       &type, NULL)) {
 			strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
 				    dirname.buf, refname);
 			goto cleanup;
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 5a430aabf623..01c9bd0dbf04 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -383,8 +383,8 @@ static int files_read_raw_ref(struct ref_store *ref_store, const char *refname,
 	if (lstat(path, &st) < 0) {
 		if (errno != ENOENT)
 			goto out;
-		if (refs_read_raw_ref(refs->packed_ref_store, refname,
-				      oid, referent, type)) {
+		if (refs_read_raw_ref(refs->packed_ref_store, refname, oid,
+				      referent, type, NULL)) {
 			errno = ENOENT;
 			goto out;
 		}
@@ -423,8 +423,8 @@ static int files_read_raw_ref(struct ref_store *ref_store, const char *refname,
 		 * ref is supposed to be, there could still be a
 		 * packed ref:
 		 */
-		if (refs_read_raw_ref(refs->packed_ref_store, refname,
-				      oid, referent, type)) {
+		if (refs_read_raw_ref(refs->packed_ref_store, refname, oid,
+				      referent, type, NULL)) {
 			errno = EISDIR;
 			goto out;
 		}
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index a457f18e93c8..03353ce48869 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -739,7 +739,8 @@ static int packed_read_raw_ref(struct ref_store *ref_store, const char *refname,
 
 	if (!rec) {
 		/* refname is not a packed reference. */
-		*failure_errno = ENOENT;
+		if (failure_errno)
+			*failure_errno = ENOENT;
 		return -1;
 	}
 
@@ -1347,6 +1348,7 @@ int is_packed_transaction_needed(struct ref_store *ref_store,
 	ret = 0;
 	for (i = 0; i < transaction->nr; i++) {
 		struct ref_update *update = transaction->updates[i];
+		int failure;
 		unsigned int type;
 		struct object_id oid;
 
@@ -1357,9 +1359,9 @@ int is_packed_transaction_needed(struct ref_store *ref_store,
 			 */
 			continue;
 
-		if (!refs_read_raw_ref(ref_store, update->refname,
-				       &oid, &referent, &type) ||
-		    errno != ENOENT) {
+		if (!refs_read_raw_ref(ref_store, update->refname, &oid,
+				       &referent, &type, &failure) ||
+		    failure != ENOENT) {
 			/*
 			 * We have to actually delete that reference
 			 * -> this transaction is needed.
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index eb97023658f8..c65d26580ce8 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -149,9 +149,9 @@ struct ref_update {
 	const char refname[FLEX_ARRAY];
 };
 
-int refs_read_raw_ref(struct ref_store *ref_store,
-		      const char *refname, struct object_id *oid,
-		      struct strbuf *referent, unsigned int *type);
+int refs_read_raw_ref(struct ref_store *ref_store, const char *refname,
+		      struct object_id *oid, struct strbuf *referent,
+		      unsigned int *type, int *failure_errno);
 
 /* Like refs_resolve_ref_unsafe, but provide access to errno code that lead to a
  * failure. */
-- 
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