sequencer: refactor transform_todos() to work on a todo_list

This refactors transform_todos() to work on a todo_list.  The function
is renamed todo_list_transform().

As rebase -p still need to check the todo list from the disk, a new
function is introduced, transform_todo_file().  It is still used by
complete_action() and edit_todo_list() for now, but they will be
replaced in a future commit.

todo_list_transform() is not a static function, because it will be used
by edit_todo_list() from rebase-interactive.c in a future commit.

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

1 files changed, 36 insertions, 18 deletions

diff --git a/sequencer.c b/sequencer.c
index c844a9b7f3..346706029c 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -4562,27 +4562,18 @@ int sequencer_add_exec_commands(struct repository *r,
 	return i;
 }
 
-int transform_todos(struct repository *r, unsigned flags)
+void todo_list_transform(struct repository *r, struct todo_list *todo_list,
+			 unsigned flags)
 {
-	const char *todo_file = rebase_path_todo();
-	struct todo_list todo_list = TODO_LIST_INIT;
 	struct strbuf buf = STRBUF_INIT;
 	struct todo_item *item;
 	int i;
 
-	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-		return error(_("could not read '%s'."), todo_file);
-
-	if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list)) {
-		todo_list_release(&todo_list);
-		return error(_("unusable todo list: '%s'"), todo_file);
-	}
-
-	for (item = todo_list.items, i = 0; i < todo_list.nr; i++, item++) {
+	for (item = todo_list->items, i = 0; i < todo_list->nr; i++, item++) {
 		/* if the item is not a command write it and continue */
 		if (item->command >= TODO_COMMENT) {
 			strbuf_addf(&buf, "%.*s\n", item->arg_len,
-				    todo_item_get_arg(&todo_list, item));
+				    todo_item_get_arg(todo_list, item));
 			continue;
 		}
 
@@ -4613,12 +4604,39 @@ int transform_todos(struct repository *r, unsigned flags)
 			strbuf_addch(&buf, '\n');
 		else
 			strbuf_addf(&buf, " %.*s\n", item->arg_len,
-				    todo_item_get_arg(&todo_list, item));
+				    todo_item_get_arg(todo_list, item));
 	}
 
-	i = write_message(buf.buf, buf.len, todo_file, 0);
+	strbuf_reset(&todo_list->buf);
+	strbuf_add(&todo_list->buf, buf.buf, buf.len);
+	strbuf_release(&buf);
+
+	if (todo_list_parse_insn_buffer(r, todo_list->buf.buf, todo_list))
+		BUG("unusable todo list");
+}
+
+int transform_todo_file(struct repository *r, unsigned flags)
+{
+	const char *todo_file = rebase_path_todo();
+	struct todo_list todo_list = TODO_LIST_INIT;
+	int res;
+
+	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
+		return error_errno(_("could not read '%s'."), todo_file);
+
+	if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list)) {
+		todo_list_release(&todo_list);
+		return error(_("unusable todo list: '%s'"), todo_file);
+	}
+
+	todo_list_transform(r, &todo_list, flags);
+
+	res = write_message(todo_list.buf.buf, todo_list.buf.len, todo_file, 0);
 	todo_list_release(&todo_list);
-	return i;
+
+	if (res)
+		return error_errno(_("could not write '%s'."), todo_file);
+	return 0;
 }
 
 enum missing_commit_check_level get_missing_commit_check_level(void)
@@ -4880,7 +4898,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 		return error(_("could not copy '%s' to '%s'."), todo_file,
 			     rebase_path_todo_backup());
 
-	if (transform_todos(r, flags | TODO_LIST_SHORTEN_IDS))
+	if (transform_todo_file(r, flags | TODO_LIST_SHORTEN_IDS))
 		return error(_("could not transform the todo list"));
 
 	strbuf_reset(buf);
@@ -4909,7 +4927,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 		return -1;
 	}
 
-	if (transform_todos(r, flags & ~(TODO_LIST_SHORTEN_IDS)))
+	if (transform_todo_file(r, flags & ~(TODO_LIST_SHORTEN_IDS)))
 		return error(_("could not transform the todo list"));
 
 	if (opts->allow_ff && skip_unnecessary_picks(r, &oid))