revision: use commit graph in get_reference()

diff --git a/revision.c b/revision.c
index b5108b75abc9ff0ef0438f4cba2e932e935ff94f..e7da2c57abf62dfafdccbc82fd03032982d16e08 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -212,7 +212,20 @@ static struct object *get_reference(struct rev_info *revs, const char *name,
 {
        struct object *object;
 
-       object = parse_object(revs->repo, oid);
+       /*
+        * If the repository has commit graphs, repo_parse_commit() avoids
+        * reading the object buffer, so use it whenever possible.
+        */
+       if (oid_object_info(revs->repo, oid, NULL) == OBJ_COMMIT) {
+               struct commit *c = lookup_commit(revs->repo, oid);
+               if (!repo_parse_commit(revs->repo, c))
+                       object = (struct object *) c;
+               else
+                       object = NULL;
+       } else {
+               object = parse_object(revs->repo, oid);
+       }
+
        if (!object) {
                if (revs->ignore_missing)
                        return object;