revert: tolerate extra spaces, tabs in insn sheet

Tolerate extra spaces and tabs as part of the the field separator in
'.git/sequencer/todo', for people with fat fingers.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/revert.c

@@ -719,18 +719,24 @@ static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *
 	unsigned char commit_sha1[20];
 	enum replay_action action;
 	char *end_of_object_name;
-	int saved, status;
+	int saved, status, padding;
 
-	if (!prefixcmp(bol, "pick ")) {
+	if (!prefixcmp(bol, "pick")) {
 		action = CHERRY_PICK;
-		bol += strlen("pick ");
-	} else if (!prefixcmp(bol, "revert ")) {
+		bol += strlen("pick");
+	} else if (!prefixcmp(bol, "revert")) {
 		action = REVERT;
-		bol += strlen("revert ");
+		bol += strlen("revert");
 	} else
 		return NULL;
 
-	end_of_object_name = bol + strcspn(bol, " \n");
+	/* Eat up extra spaces/ tabs before object name */
+	padding = strspn(bol, " \t");
+	if (!padding)
+		return NULL;
+	bol += padding;
+
+	end_of_object_name = bol + strcspn(bol, " \t\n");
 	saved = *end_of_object_name;
 	*end_of_object_name = '\0';
 	status = get_sha1(bol, commit_sha1);

t/t3510-cherry-pick-sequence.sh

@@ -492,6 +492,17 @@ test_expect_success 'malformed instruction sheet 3' '
 	test_must_fail git cherry-pick --continue
 '
 
+test_expect_success 'instruction sheet, fat-fingers version' '
+	pristine_detach initial &&
+	test_must_fail git cherry-pick base..anotherpick &&
+	echo "c" >foo &&
+	git add foo &&
+	git commit &&
+	sed "s/pick \([0-9a-f]*\)/pick 	 \1 	/" .git/sequencer/todo >new_sheet &&
+	cp new_sheet .git/sequencer/todo &&
+	git cherry-pick --continue
+'
+
 test_expect_success 'commit descriptions in insn sheet are optional' '
 	pristine_detach initial &&
 	test_must_fail git cherry-pick base..anotherpick &&