commit_graft_prepared = 1;
 }
 
-static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
+struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 {
        int pos;
        prepare_commit_graft();
        }
        item->date = parse_commit_date(bufptr, tail);
 
-       if (track_object_refs) {
-               unsigned i = 0;
-               struct commit_list *p;
-               struct object_refs *refs = alloc_object_refs(n_refs);
-               if (item->tree)
-                       refs->ref[i++] = &item->tree->object;
-               for (p = item->parents; p; p = p->next)
-                       refs->ref[i++] = &p->item->object;
-               set_object_refs(&item->object, refs);
-       }
-
        return 0;
 }
 
        unsigned long size;
        int ret;
 
+       if (!item)
+               return -1;
        if (item->object.parsed)
                return 0;
        buffer = read_sha1_file(item->object.sha1, &type, &size);
 
        while (parents) {
                struct commit *commit = parents->item;
-               parse_commit(commit);
-               if (!(commit->object.flags & mark)) {
+               if (!parse_commit(commit) && !(commit->object.flags & mark)) {
                        commit->object.flags |= mark;
                        insert_by_date(commit, list);
                }
                 */
                return commit_list_insert(one, &result);
 
-       parse_commit(one);
-       parse_commit(two);
+       if (parse_commit(one))
+               return NULL;
+       if (parse_commit(two))
+               return NULL;
 
        one->object.flags |= PARENT1;
        two->object.flags |= PARENT2;
                        parents = parents->next;
                        if ((p->object.flags & flags) == flags)
                                continue;
-                       parse_commit(p);
+                       if (parse_commit(p))
+                               return NULL;
                        p->object.flags |= flags;
                        insert_by_date(p, &list);
                }