refs: make verify_refname_available() virtual

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

3 files changed, 25 insertions, 6 deletions

diff --git a/refs.c b/refs.c
index 775c54eb4..a5c11088f 100644
--- a/refs.c
+++ b/refs.c
@@ -1428,3 +1428,13 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 
 	return refs->be->transaction_commit(refs, transaction, err);
 }
+
+int verify_refname_available(const char *refname,
+			     const struct string_list *extra,
+			     const struct string_list *skip,
+			     struct strbuf *err)
+{
+	struct ref_store *refs = get_ref_store(NULL);
+
+	return refs->be->verify_refname_available(refs, refname, extra, skip, err);
+}
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 9cf2f82f7..44eef1cec 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2549,13 +2549,14 @@ out:
 	return ret;
 }
 
-int verify_refname_available(const char *newname,
-			     const struct string_list *extras,
-			     const struct string_list *skip,
-			     struct strbuf *err)
+static int files_verify_refname_available(struct ref_store *ref_store,
+					  const char *newname,
+					  const struct string_list *extras,
+					  const struct string_list *skip,
+					  struct strbuf *err)
 {
 	struct files_ref_store *refs =
-		get_files_ref_store(NULL, "verify_refname_available");
+		files_downcast(ref_store, 1, "verify_refname_available");
 	struct ref_dir *packed_refs = get_packed_refs(refs);
 	struct ref_dir *loose_refs = get_loose_refs(refs);
 
@@ -4021,5 +4022,6 @@ struct ref_storage_be refs_be_files = {
 	files_ref_store_create,
 	files_transaction_commit,
 
-	files_read_raw_ref
+	files_read_raw_ref,
+	files_verify_refname_available
 };
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 19cb6e11a..6c698f442 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -542,6 +542,12 @@ typedef int read_raw_ref_fn(struct ref_store *ref_store,
 			    const char *refname, unsigned char *sha1,
 			    struct strbuf *referent, unsigned int *type);
 
+typedef int verify_refname_available_fn(struct ref_store *ref_store,
+					const char *newname,
+					const struct string_list *extras,
+					const struct string_list *skip,
+					struct strbuf *err);
+
 struct ref_storage_be {
 	struct ref_storage_be *next;
 	const char *name;
@@ -549,6 +555,7 @@ struct ref_storage_be {
 	ref_transaction_commit_fn *transaction_commit;
 
 	read_raw_ref_fn *read_raw_ref;
+	verify_refname_available_fn *verify_refname_available;
 };
 
 extern struct ref_storage_be refs_be_files;