shallow: free grafts when unregistering them

When removing a graft via `unregister_shallow()` we remove it from the
grafts array, but do not free the structure. Fix this to plug the leak.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

shallow.c

@@ -51,10 +51,12 @@ int unregister_shallow(const struct object_id *oid)
 	int pos = commit_graft_pos(the_repository, oid);
 	if (pos < 0)
 		return -1;
-	if (pos + 1 < the_repository->parsed_objects->grafts_nr)
+	if (pos + 1 < the_repository->parsed_objects->grafts_nr) {
+		free(the_repository->parsed_objects->grafts[pos]);
 		MOVE_ARRAY(the_repository->parsed_objects->grafts + pos,
 			   the_repository->parsed_objects->grafts + pos + 1,
 			   the_repository->parsed_objects->grafts_nr - pos - 1);
+	}
 	the_repository->parsed_objects->grafts_nr--;
 	return 0;
 }

t/t5537-fetch-shallow.sh

@@ -5,6 +5,7 @@ test_description='fetch/clone from a shallow clone'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 commit() {