1 files changed, 154 insertions, 44 deletions

diff --git a/sequencer.c b/sequencer.c
index 1d206fd224..34ebf8ed94 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -770,7 +770,7 @@ static int parse_key_value_squoted(char *buf, struct string_list *list)
  *	GIT_AUTHOR_DATE='$author_date'
  *
  * where $author_name, $author_email and $author_date are quoted. We are strict
- * with our parsing, as the file was meant to be eval'd in the old
+ * with our parsing, as the file was meant to be eval'd in the now-removed
  * git-am.sh/git-rebase--interactive.sh scripts, and thus if the file differs
  * from what this function expects, it is better to bail out than to do
  * something that the user does not expect.
@@ -2079,6 +2079,18 @@ const char *todo_item_get_arg(struct todo_list *todo_list,
 	return todo_list->buf.buf + item->arg_offset;
 }
 
+static int is_command(enum todo_command command, const char **bol)
+{
+	const char *str = todo_command_info[command].str;
+	const char nick = todo_command_info[command].c;
+	const char *p = *bol + 1;
+
+	return skip_prefix(*bol, str, bol) ||
+		((nick && **bol == nick) &&
+		 (*p == ' ' || *p == '\t' || *p == '\n' || *p == '\r' || !*p) &&
+		 (*bol = p));
+}
+
 static int parse_insn_line(struct repository *r, struct todo_item *item,
 			   const char *buf, const char *bol, char *eol)
 {
@@ -2100,12 +2112,7 @@ static int parse_insn_line(struct repository *r, struct todo_item *item,
 	}
 
 	for (i = 0; i < TODO_COMMENT; i++)
-		if (skip_prefix(bol, todo_command_info[i].str, &bol)) {
-			item->command = i;
-			break;
-		} else if ((bol + 1 == eol || bol[1] == ' ') &&
-			   *bol == todo_command_info[i].c) {
-			bol++;
+		if (is_command(i, &bol)) {
 			item->command = i;
 			break;
 		}
@@ -2173,34 +2180,26 @@ static int parse_insn_line(struct repository *r, struct todo_item *item,
 
 int sequencer_get_last_command(struct repository *r, enum replay_action *action)
 {
-	struct todo_item item;
-	char *eol;
-	const char *todo_file;
+	const char *todo_file, *bol;
 	struct strbuf buf = STRBUF_INIT;
-	int ret = -1;
+	int ret = 0;
 
 	todo_file = git_path_todo_file();
 	if (strbuf_read_file(&buf, todo_file, 0) < 0) {
-		if (errno == ENOENT)
+		if (errno == ENOENT || errno == ENOTDIR)
 			return -1;
 		else
 			return error_errno("unable to open '%s'", todo_file);
 	}
-	eol = strchrnul(buf.buf, '\n');
-	if (buf.buf != eol && eol[-1] == '\r')
-		eol--; /* strip Carriage Return */
-	if (parse_insn_line(r, &item, buf.buf, buf.buf, eol))
-		goto fail;
-	if (item.command == TODO_PICK)
+	bol = buf.buf + strspn(buf.buf, " \t\r\n");
+	if (is_command(TODO_PICK, &bol) && (*bol == ' ' || *bol == '\t'))
 		*action = REPLAY_PICK;
-	else if (item.command == TODO_REVERT)
+	else if (is_command(TODO_REVERT, &bol) &&
+		 (*bol == ' ' || *bol == '\t'))
 		*action = REPLAY_REVERT;
 	else
-		goto fail;
-
-	ret = 0;
+		ret = -1;
 
- fail:
 	strbuf_release(&buf);
 
 	return ret;
@@ -2314,19 +2313,21 @@ static int have_finished_the_last_pick(void)
 	return ret;
 }
 
-void sequencer_post_commit_cleanup(struct repository *r)
+void sequencer_post_commit_cleanup(struct repository *r, int verbose)
 {
 	struct replay_opts opts = REPLAY_OPTS_INIT;
 	int need_cleanup = 0;
 
 	if (file_exists(git_path_cherry_pick_head(r))) {
-		unlink(git_path_cherry_pick_head(r));
+		if (!unlink(git_path_cherry_pick_head(r)) && verbose)
+			warning(_("cancelling a cherry picking in progress"));
 		opts.action = REPLAY_PICK;
 		need_cleanup = 1;
 	}
 
 	if (file_exists(git_path_revert_head(r))) {
-		unlink(git_path_revert_head(r));
+		if (!unlink(git_path_revert_head(r)) && verbose)
+			warning(_("cancelling a revert in progress"));
 		opts.action = REPLAY_REVERT;
 		need_cleanup = 1;
 	}
@@ -2653,15 +2654,41 @@ static int walk_revs_populate_todo(struct todo_list *todo_list,
 	return 0;
 }
 
-static int create_seq_dir(void)
+static int create_seq_dir(struct repository *r)
 {
-	if (file_exists(git_path_seq_dir())) {
-		error(_("a cherry-pick or revert is already in progress"));
-		advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
+	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 | %s--abort | --quit)\"");
+			break;
+		case REPLAY_PICK:
+			in_progress_error = _("cherry-pick is already in progress");
+			in_progress_advice =
+			_("try \"git cherry-pick (--continue | %s--abort | --quit)\"");
+			break;
+		default:
+			BUG("unexpected action in create_seq_dir");
+		}
+	}
+	if (in_progress_error) {
+		error("%s", in_progress_error);
+		if (advice_sequencer_in_use)
+			advise(in_progress_advice,
+				advise_skip ? "--skip | " : "");
 		return -1;
-	} else if (mkdir(git_path_seq_dir(), 0777) < 0)
+	}
+	if (mkdir(git_path_seq_dir(), 0777) < 0)
 		return error_errno(_("could not create sequencer directory '%s'"),
 				   git_path_seq_dir());
+
 	return 0;
 }
 
@@ -2712,15 +2739,20 @@ static int rollback_is_safe(void)
 	return oideq(&actual_head, &expected_head);
 }
 
-static int reset_for_rollback(const struct object_id *oid)
+static int reset_merge(const struct object_id *oid)
 {
-	const char *argv[4];	/* reset --merge <arg> + NULL */
+	int ret;
+	struct argv_array argv = ARGV_ARRAY_INIT;
 
-	argv[0] = "reset";
-	argv[1] = "--merge";
-	argv[2] = oid_to_hex(oid);
-	argv[3] = NULL;
-	return run_command_v_opt(argv, RUN_GIT_CMD);
+	argv_array_pushl(&argv, "reset", "--merge", NULL);
+
+	if (!is_null_oid(oid))
+		argv_array_push(&argv, oid_to_hex(oid));
+
+	ret = run_command_v_opt(argv.argv, RUN_GIT_CMD);
+	argv_array_clear(&argv);
+
+	return ret;
 }
 
 static int rollback_single_pick(struct repository *r)
@@ -2734,7 +2766,16 @@ static int rollback_single_pick(struct repository *r)
 		return error(_("cannot resolve HEAD"));
 	if (is_null_oid(&head_oid))
 		return error(_("cannot abort from a branch yet to be born"));
-	return reset_for_rollback(&head_oid);
+	return reset_merge(&head_oid);
+}
+
+static int skip_single_pick(void)
+{
+	struct object_id head;
+
+	if (read_ref_full("HEAD", 0, &head, NULL))
+		return error(_("cannot resolve HEAD"));
+	return reset_merge(&head);
 }
 
 int sequencer_rollback(struct repository *r, struct replay_opts *opts)
@@ -2777,7 +2818,7 @@ int sequencer_rollback(struct repository *r, struct replay_opts *opts)
 		warning(_("You seem to have moved HEAD. "
 			  "Not rewinding, check your HEAD!"));
 	} else
-	if (reset_for_rollback(&oid))
+	if (reset_merge(&oid))
 		goto fail;
 	strbuf_release(&buf);
 	return sequencer_remove_state(opts);
@@ -2786,6 +2827,70 @@ fail:
 	return -1;
 }
 
+int sequencer_skip(struct repository *r, struct replay_opts *opts)
+{
+	enum replay_action action = -1;
+	sequencer_get_last_command(r, &action);
+
+	/*
+	 * Check whether the subcommand requested to skip the commit is actually
+	 * in progress and that it's safe to skip the commit.
+	 *
+	 * opts->action tells us which subcommand requested to skip the commit.
+	 * If the corresponding .git/<ACTION>_HEAD exists, we know that the
+	 * action is in progress and we can skip the commit.
+	 *
+	 * Otherwise we check that the last instruction was related to the
+	 * particular subcommand we're trying to execute and barf if that's not
+	 * the case.
+	 *
+	 * Finally we check that the rollback is "safe", i.e., has the HEAD
+	 * moved? In this case, it doesn't make sense to "reset the merge" and
+	 * "skip the commit" as the user already handled this by committing. But
+	 * we'd not want to barf here, instead give advice on how to proceed. We
+	 * only need to check that when .git/<ACTION>_HEAD doesn't exist because
+	 * it gets removed when the user commits, so if it still exists we're
+	 * sure the user can't have committed before.
+	 */
+	switch (opts->action) {
+	case REPLAY_REVERT:
+		if (!file_exists(git_path_revert_head(r))) {
+			if (action != REPLAY_REVERT)
+				return error(_("no revert in progress"));
+			if (!rollback_is_safe())
+				goto give_advice;
+		}
+		break;
+	case REPLAY_PICK:
+		if (!file_exists(git_path_cherry_pick_head(r))) {
+			if (action != REPLAY_PICK)
+				return error(_("no cherry-pick in progress"));
+			if (!rollback_is_safe())
+				goto give_advice;
+		}
+		break;
+	default:
+		BUG("unexpected action in sequencer_skip");
+	}
+
+	if (skip_single_pick())
+		return error(_("failed to skip the commit"));
+	if (!is_directory(git_path_seq_dir()))
+		return 0;
+
+	return sequencer_continue(r, opts);
+
+give_advice:
+	error(_("there is nothing to skip"));
+
+	if (advice_resolve_conflict) {
+		advise(_("have you committed already?\n"
+			 "try \"git %s --continue\""),
+			 action == REPLAY_REVERT ? "revert" : "cherry-pick");
+	}
+	return -1;
+}
+
 static int save_todo(struct todo_list *todo_list, struct replay_opts *opts)
 {
 	struct lock_file todo_lock = LOCK_INIT;
@@ -3197,7 +3302,7 @@ static int do_reset(struct repository *r,
 		return error_resolve_conflict(_(action_name(opts)));
 	}
 
-	if (!fill_tree_descriptor(&desc, &oid)) {
+	if (!fill_tree_descriptor(r, &desc, &oid)) {
 		error(_("failed to find tree of %s"), oid_to_hex(&oid));
 		rollback_lock_file(&lock);
 		free((void *)desc.buffer);
@@ -3404,6 +3509,10 @@ static int do_merge(struct repository *r,
 		rollback_lock_file(&lock);
 		ret = fast_forward_to(r, &commit->object.oid,
 				      &head_commit->object.oid, 0, opts);
+		if (flags & TODO_EDIT_MERGE_MSG) {
+			run_commit_flags |= AMEND_MSG;
+			goto fast_forward_edit;
+		}
 		goto leave_merge;
 	}
 
@@ -3507,6 +3616,7 @@ static int do_merge(struct repository *r,
 		 * value (a negative one would indicate that the `merge`
 		 * command needs to be rescheduled).
 		 */
+	fast_forward_edit:
 		ret = !!run_git_commit(r, git_path_merge_msg(r), opts,
 				       run_commit_flags);
 
@@ -3731,7 +3841,7 @@ static int pick_commits(struct repository *r,
 			unlink(rebase_path_author_script());
 			unlink(rebase_path_stopped_sha());
 			unlink(rebase_path_amend());
-			unlink(git_path_merge_head(the_repository));
+			unlink(git_path_merge_head(r));
 			delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 
 			if (item->command == TODO_BREAK) {
@@ -4116,7 +4226,7 @@ static int commit_staged_changes(struct repository *r,
 			   opts, flags))
 		return error(_("could not commit staged changes."));
 	unlink(rebase_path_amend());
-	unlink(git_path_merge_head(the_repository));
+	unlink(git_path_merge_head(r));
 	if (final_fixup) {
 		unlink(rebase_path_fixup_msg());
 		unlink(rebase_path_squash_msg());
@@ -4251,7 +4361,7 @@ int sequencer_pick_revisions(struct repository *r,
 	 */
 
 	if (walk_revs_populate_todo(&todo_list, opts) ||
-			create_seq_dir() < 0)
+			create_seq_dir(r) < 0)
 		return -1;
 	if (get_oid("HEAD", &oid) && (opts->action == REPLAY_REVERT))
 		return error(_("can't revert as initial commit"));