rebase-interactive: rewrite edit_todo_list() to handle the initial edit

edit_todo_list() is changed to work on a todo_list, and to handle the
initial edition of the todo list (ie. making a backup of the todo
list).

It does not check for dropped commits yet, as todo_list_check() does not
take the commits that have already been processed by the rebase (ie. the
todo list is edited in the middle of a rebase session).

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 29 insertions, 24 deletions

diff --git a/rebase-interactive.c b/rebase-interactive.c
index 807f8370db..aa18ae82b7 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -87,35 +87,40 @@ void append_todo_help(unsigned keep_empty, int command_count,
 	}
 }
 
-int edit_todo_list(struct repository *r, unsigned flags)
+int edit_todo_list(struct repository *r, struct todo_list *todo_list,
+		   struct todo_list *new_todo, const char *shortrevisions,
+		   const char *shortonto, unsigned flags)
 {
 	const char *todo_file = rebase_path_todo();
-	struct todo_list todo_list = TODO_LIST_INIT;
-	int res = 0;
-
-	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-		return error_errno(_("could not read '%s'."), todo_file);
-
-	strbuf_stripspace(&todo_list.buf, 1);
-	todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list);
-	if (todo_list_write_to_file(r, &todo_list, todo_file, NULL, NULL, -1,
-				    flags | TODO_LIST_SHORTEN_IDS | TODO_LIST_APPEND_TODO_HELP)) {
-		todo_list_release(&todo_list);
-		return -1;
-	}
+	unsigned initial = shortrevisions && shortonto;
 
-	strbuf_reset(&todo_list.buf);
-	if (launch_sequence_editor(todo_file, &todo_list.buf, NULL)) {
-		todo_list_release(&todo_list);
-		return -1;
-	}
+	/* If the user is editing the todo list, we first try to parse
+	 * it.  If there is an error, we do not return, because the user
+	 * might want to fix it in the first place. */
+	if (!initial)
+		todo_list_parse_insn_buffer(r, todo_list->buf.buf, todo_list);
 
-	if (!todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list))
-		res = todo_list_write_to_file(r, &todo_list, todo_file, NULL, NULL, -1,
-					      flags & ~(TODO_LIST_SHORTEN_IDS));
+	if (todo_list_write_to_file(r, todo_list, todo_file, shortrevisions, shortonto,
+				    -1, flags | TODO_LIST_SHORTEN_IDS | TODO_LIST_APPEND_TODO_HELP))
+		return error_errno(_("could not write '%s'"), todo_file);
 
-	todo_list_release(&todo_list);
-	return res;
+	if (initial && copy_file(rebase_path_todo_backup(), todo_file, 0666))
+		return error(_("could not copy '%s' to '%s'."), todo_file,
+			     rebase_path_todo_backup());
+
+	if (launch_sequence_editor(todo_file, &new_todo->buf, NULL))
+		return -2;
+
+	strbuf_stripspace(&new_todo->buf, 1);
+	if (initial && new_todo->buf.len == 0)
+		return -3;
+
+	/* For the initial edit, the todo list gets parsed in
+	 * complete_action(). */
+	if (!initial)
+		return todo_list_parse_insn_buffer(r, new_todo->buf.buf, new_todo);
+
+	return 0;
 }
 
 define_commit_slab(commit_seen, unsigned char);