cherry-pick/revert: advise using --skip

The previous commit introduced a --skip flag for cherry-pick and
revert. Update the advice messages, to tell users about this less
cumbersome way of skipping commits. Also add tests to ensure
everything is working fine.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/commit.c

@@ -60,15 +60,18 @@ N_("The previous cherry-pick is now empty, possibly due to conflict resolution.\
 "\n");
 
 static const char empty_cherry_pick_advice_single[] =
-N_("Otherwise, please use 'git reset'\n");
+N_("Otherwise, please use 'git cherry-pick --skip'\n");
 
 static const char empty_cherry_pick_advice_multi[] =
-N_("If you wish to skip this commit, use:\n"
+N_("and then use:\n"
 "\n"
-"    git reset\n"
+"    git cherry-pick --continue\n"
 "\n"
-"Then \"git cherry-pick --continue\" will resume cherry-picking\n"
-"the remaining commits.\n");
+"to resume cherry-picking the remaining commits.\n"
+"If you wish to skip this commit, use:\n"
+"\n"
+"    git cherry-pick --skip\n"
+"\n");
 
 static const char *color_status_slots[] = {
 	[WT_STATUS_HEADER]	  = "header",

sequencer.c

@@ -2655,18 +2655,20 @@ static int create_seq_dir(struct repository *r)
 	enum replay_action action;
 	const char *in_progress_error = NULL;
 	const char *in_progress_advice = NULL;
+	unsigned int advise_skip = file_exists(git_path_revert_head(r)) ||
+				file_exists(git_path_cherry_pick_head(r));
 
 	if (!sequencer_get_last_command(r, &action)) {
 		switch (action) {
 		case REPLAY_REVERT:
 			in_progress_error = _("revert is already in progress");
 			in_progress_advice =
-			_("try \"git revert (--continue | --abort | --quit)\"");
+			_("try \"git revert (--continue | %s--abort | --quit)\"");
 			break;
 		case REPLAY_PICK:
 			in_progress_error = _("cherry-pick is already in progress");
 			in_progress_advice =
-			_("try \"git cherry-pick (--continue | --abort | --quit)\"");
+			_("try \"git cherry-pick (--continue | %s--abort | --quit)\"");
 			break;
 		default:
 			BUG("unexpected action in create_seq_dir");
@@ -2675,7 +2677,8 @@ static int create_seq_dir(struct repository *r)
 	if (in_progress_error) {
 		error("%s", in_progress_error);
 		if (advice_sequencer_in_use)
-			advise("%s", in_progress_advice);
+			advise(in_progress_advice,
+				advise_skip ? "--skip | " : "");
 		return -1;
 	}
 	if (mkdir(git_path_seq_dir(), 0777) < 0)

t/t3510-cherry-pick-sequence.sh

@@ -172,6 +172,26 @@ test_expect_success 'check advice when we move HEAD by committing' '
 	test_i18ncmp expect advice
 '
 
+test_expect_success 'selectively advise --skip while launching another sequence' '
+	pristine_detach initial &&
+	cat >expect <<-EOF &&
+	error: cherry-pick is already in progress
+	hint: try "git cherry-pick (--continue | --skip | --abort | --quit)"
+	fatal: cherry-pick failed
+	EOF
+	test_must_fail git cherry-pick picked..yetanotherpick &&
+	test_must_fail git cherry-pick picked..yetanotherpick 2>advice &&
+	test_i18ncmp expect advice &&
+	cat >expect <<-EOF &&
+	error: cherry-pick is already in progress
+	hint: try "git cherry-pick (--continue | --abort | --quit)"
+	fatal: cherry-pick failed
+	EOF
+	git reset --merge &&
+	test_must_fail git cherry-pick picked..yetanotherpick 2>advice &&
+	test_i18ncmp expect advice
+'
+
 test_expect_success 'allow skipping commit but not abort for a new history' '
 	pristine_detach initial &&
 	cat >expect <<-EOF &&