[PATCH v7 15/33] refs: add method to rename refs

@@ -1415,3 +1415,8 @@ int delete_refs(struct string_list *refnames)
 {
 	return the_refs_backend->delete_refs(refnames);
 }
+
+int rename_ref(const char *oldref, const char *newref, const char *logmsg)
+{
+	return the_refs_backend->rename_ref(oldref, newref, logmsg);
+}

@@ -2359,7 +2359,8 @@ static int commit_ref_update(struct ref_lock *lock,
 			     const unsigned char *sha1, const char *logmsg,
 			     int flags, struct strbuf *err);
 
-int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
+static int files_rename_ref(const char *oldrefname, const char *newrefname,
+			    const char *logmsg)
 {
 	unsigned char sha1[20], orig_sha1[20];
 	int flag = 0, logmoved = 0;

@@ -3449,6 +3450,7 @@ struct ref_storage_be refs_be_files = {
 	files_peel_ref,
 	files_create_symref,
 	files_delete_refs,
+	files_rename_ref,
 
 	files_read_raw_ref,
 	files_verify_refname_available,

@@ -195,6 +195,11 @@ const char *find_descendant_ref(const char *dirname,
 				const struct string_list *extras,
 				const struct string_list *skip);
 
+/*
+ * Check if the new name does not conflict with any existing refs
+ * (other than possibly the old ref).  Return 0 if the ref can be
+ * renamed to the new name.
+ */
 int rename_ref_available(const char *oldname, const char *newname);
 
 /* We allow "recursive" symbolic refs. Only within reason, though */

@@ -241,6 +246,8 @@ typedef int create_symref_fn(const char *ref_target,
 			     const char *refs_heads_master,
 			     const char *logmsg);
 typedef int delete_refs_fn(struct string_list *refnames);
+typedef int rename_ref_fn(const char *oldref, const char *newref,
+			  const char *logmsg);
 
 /* resolution methods */
 typedef int read_raw_ref_fn(const char *refname, unsigned char *sha1,

@@ -272,6 +279,7 @@ struct ref_storage_be {
 	peel_ref_fn *peel_ref;
 	create_symref_fn *create_symref;
 	delete_refs_fn *delete_refs;
+	rename_ref_fn *rename_ref;
 
 	read_raw_ref_fn *read_raw_ref;
 	verify_refname_available_fn *verify_refname_available;