[PATCH 02/34] sequencer (rebase -i): implement the 'noop' command

[Johannes Schindelin <johannes.schindelin@xxxxxx>]

The 'noop' command is probably the most boring of all rebase -i commands
to support in the sequencer.

Which makes it an excellent candidate for this first stab to add support
for rebase -i's commands to the sequencer.

For the moment, let's also treat empty lines and commented-out lines as
'noop'; We will refine that handling later in this patch series.

Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
---
 sequencer.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 5598534..f85dc9c 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -644,12 +644,14 @@ static int allow_empty(struct replay_opts *opts, struct commit *commit)
 
 enum todo_command {
 	TODO_PICK,
-	TODO_REVERT
+	TODO_REVERT,
+	TODO_NOOP
 };
 
 static const char *todo_command_strings[] = {
 	"pick",
-	"revert"
+	"revert",
+	"noop"
 };
 
 static const char *command_to_string(const enum todo_command command)
@@ -916,6 +918,14 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
 	/* left-trim */
 	bol += strspn(bol, " \t");
 
+	if (bol == eol || *bol == '\r' || *bol == comment_line_char) {
+		item->command = TODO_NOOP;
+		item->commit = NULL;
+		item->arg = bol;
+		item->arg_len = eol - bol;
+		return 0;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(todo_command_strings); i++)
 		if (skip_prefix(bol, todo_command_strings[i], &bol)) {
 			item->command = i;
@@ -924,6 +934,13 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
 	if (i >= ARRAY_SIZE(todo_command_strings))
 		return -1;
 
+	if (item->command == TODO_NOOP) {
+		item->commit = NULL;
+		item->arg = bol;
+		item->arg_len = eol - bol;
+		return 0;
+	}
+
 	/* Eat up extra spaces/ tabs before object name */
 	padding = strspn(bol, " \t");
 	if (!padding)
@@ -1277,7 +1294,12 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
 		struct todo_item *item = todo_list->items + todo_list->current;
 		if (save_todo(todo_list, opts))
 			return -1;
-		res = do_pick_commit(item->command, item->commit, opts);
+		if (item->command <= TODO_REVERT)
+			res = do_pick_commit(item->command, item->commit,
+					opts);
+		else if (item->command != TODO_NOOP)
+			return error("Unknown command %d", item->command);
+
 		todo_list->current++;
 		if (res)
 			return res;
-- 
2.10.0.rc2.102.g5c102ec