sequencer: export commit_list_append()

This function can be used in other parts of git.  Give it a new home
in commit.c.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

commit.c

@@ -1214,3 +1214,30 @@ struct commit *get_merge_parent(const char *name)
 	}
 	return commit;
 }
+
+/*
+ * Append a commit to the end of the commit_list.
+ *
+ * next starts by pointing to the variable that holds the head of an
+ * empty commit_list, and is updated to point to the "next" field of
+ * the last item on the list as new commits are appended.
+ *
+ * Usage example:
+ *
+ *     struct commit_list *list;
+ *     struct commit_list **next = &list;
+ *
+ *     next = commit_list_append(c1, next);
+ *     next = commit_list_append(c2, next);
+ *     assert(commit_list_count(list) == 2);
+ *     return list;
+ */
+struct commit_list **commit_list_append(struct commit *commit,
+					struct commit_list **next)
+{
+	struct commit_list *new = xmalloc(sizeof(struct commit_list));
+	new->item = commit;
+	*next = new;
+	new->next = NULL;
+	return &new->next;
+}

commit.h

@@ -53,6 +53,8 @@ int find_commit_subject(const char *commit_buffer, const char **subject);
 
 struct commit_list *commit_list_insert(struct commit *item,
 					struct commit_list **list);
+struct commit_list **commit_list_append(struct commit *commit,
+					struct commit_list **next);
 unsigned commit_list_count(const struct commit_list *l);
 struct commit_list *commit_list_insert_by_date(struct commit *item,
 				    struct commit_list **list);

sequencer.c

@@ -468,33 +468,6 @@ static void read_and_refresh_cache(struct replay_opts *opts)
 	rollback_lock_file(&index_lock);
 }
 
-/*
- * Append a commit to the end of the commit_list.
- *
- * next starts by pointing to the variable that holds the head of an
- * empty commit_list, and is updated to point to the "next" field of
- * the last item on the list as new commits are appended.
- *
- * Usage example:
- *
- *     struct commit_list *list;
- *     struct commit_list **next = &list;
- *
- *     next = commit_list_append(c1, next);
- *     next = commit_list_append(c2, next);
- *     assert(commit_list_count(list) == 2);
- *     return list;
- */
-static struct commit_list **commit_list_append(struct commit *commit,
-					       struct commit_list **next)
-{
-	struct commit_list *new = xmalloc(sizeof(struct commit_list));
-	new->item = commit;
-	*next = new;
-	new->next = NULL;
-	return &new->next;
-}
-
 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 		struct replay_opts *opts)
 {