commit: add gentle reference lookup method

The lookup_commit_reference_by_name() method uses lookup_commit_reference()
without an option to use lookup_commit_reference_gently(). Create a gentle
version of the method so it can be used in locations where non-commits may
be found but error messages should be silenced.

Signed-off-by: Derrick Stolee <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: derrickstolee

commit.c

@@ -84,13 +84,19 @@ struct commit *lookup_commit(struct repository *r, const struct object_id *oid)
 }
 
 struct commit *lookup_commit_reference_by_name(const char *name)
+{
+	return lookup_commit_reference_by_name_gently(name, 0);
+}
+
+struct commit *lookup_commit_reference_by_name_gently(const char *name,
+						      int quiet)
 {
 	struct object_id oid;
 	struct commit *commit;
 
 	if (repo_get_oid_committish(the_repository, name, &oid))
 		return NULL;
-	commit = lookup_commit_reference(the_repository, &oid);
+	commit = lookup_commit_reference_gently(the_repository, &oid, quiet);
 	if (repo_parse_commit(the_repository, commit))
 		return NULL;
 	return commit;

commit.h

@@ -81,6 +81,8 @@ struct commit *lookup_commit_reference_gently(struct repository *r,
 					      const struct object_id *oid,
 					      int quiet);
 struct commit *lookup_commit_reference_by_name(const char *name);
+struct commit *lookup_commit_reference_by_name_gently(const char *name,
+						      int quiet);
 
 /*
  * Look up object named by "oid", dereference tag as necessary,