return c;
 }
 
+struct commit_list *copy_commit_list(struct commit_list *list)
+{
+       struct commit_list *head = NULL;
+       struct commit_list **pp = &head;
+       while (list) {
+               struct commit_list *new;
+               new = xmalloc(sizeof(struct commit_list));
+               new->item = list->item;
+               new->next = NULL;
+               *pp = new;
+               pp = &new->next;
+               list = list->next;
+       }
+       return head;
+}
+
 void free_commit_list(struct commit_list *list)
 {
        while (list) {