/*
 * Builtin "git commit"
 *
 * Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>
 * Based on git-commit.sh by Junio C Hamano and Linus Torvalds
 */

#include "cache.h"
#include "config.h"
#include "lockfile.h"
#include "cache-tree.h"
#include "color.h"
#include "dir.h"
#include "builtin.h"
#include "diff.h"
#include "diffcore.h"
#include "commit.h"
#include "revision.h"
#include "wt-status.h"
#include "run-command.h"
#include "refs.h"
#include "log-tree.h"
#include "strbuf.h"
#include "utf8.h"
#include "parse-options.h"
#include "string-list.h"
#include "rerere.h"
#include "unpack-trees.h"
#include "quote.h"
#include "submodule.h"
#include "gpg-interface.h"
#include "column.h"
#include "sequencer.h"
#include "mailmap.h"
#include "help.h"

static const char * const builtin_commit_usage[] = {
	N_("git commit [<options>] [--] <pathspec>..."),
	NULL
};

static const char * const builtin_status_usage[] = {
	N_("git status [<options>] [--] <pathspec>..."),
	NULL
};

static const char empty_amend_advice[] =
N_("You asked to amend the most recent commit, but doing so would make\n"
"it empty. You can repeat your command with --allow-empty, or you can\n"
"remove the commit entirely with \"git reset HEAD^\".\n");

static const char empty_cherry_pick_advice[] =
N_("The previous cherry-pick is now empty, possibly due to conflict resolution.\n"
"If you wish to commit it anyway, use:\n"
"\n"
"    git commit --allow-empty\n"
"\n");

static const char empty_cherry_pick_advice_single[] =
N_("Otherwise, please use 'git reset'\n");

static const char empty_cherry_pick_advice_multi[] =
N_("If you wish to skip this commit, use:\n"
"\n"
"    git reset\n"
"\n"
"Then \"git cherry-pick --continue\" will resume cherry-picking\n"
"the remaining commits.\n");

static const char *color_status_slots[] = {
	[WT_STATUS_HEADER]	  = "header",
	[WT_STATUS_UPDATED]	  = "updated",
	[WT_STATUS_CHANGED]	  = "changed",
	[WT_STATUS_UNTRACKED]	  = "untracked",
	[WT_STATUS_NOBRANCH]	  = "noBranch",
	[WT_STATUS_UNMERGED]	  = "unmerged",
	[WT_STATUS_LOCAL_BRANCH]  = "localBranch",
	[WT_STATUS_REMOTE_BRANCH] = "remoteBranch",
	[WT_STATUS_ONBRANCH]	  = "branch",
};

static const char *use_message_buffer;
static struct lock_file index_lock; /* real index */
static struct lock_file false_lock; /* used only for partial commits */
static enum {
	COMMIT_AS_IS = 1,
	COMMIT_NORMAL,
	COMMIT_PARTIAL
} commit_style;

static const char *logfile, *force_author;
static const char *template_file;
/*
 * The _message variables are commit names from which to take
 * the commit message and/or authorship.
 */
static const char *author_message, *author_message_buffer;
static char *edit_message, *use_message;
static char *fixup_message, *squash_message;
static int all, also, interactive, patch_interactive, only, amend, signoff;
static int edit_flag = -1; /* unspecified */
static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
static int config_commit_verbose = -1; /* unspecified */
static int no_post_rewrite, allow_empty_message;
static char *untracked_files_arg, *force_date, *ignore_submodule_arg, *ignored_arg;
static char *sign_commit;

/*
 * The default commit message cleanup mode will remove the lines
 * beginning with # (shell comments) and leading and trailing
 * whitespaces (empty lines or containing only whitespaces)
 * if editor is used, and only the whitespaces if the message
 * is specified explicitly.
 */
static enum commit_msg_cleanup_mode cleanup_mode;
static const char *cleanup_arg;

static enum commit_whence whence;
static int sequencer_in_use;
static int use_editor = 1, include_status = 1;
static int have_option_m;
static struct strbuf message = STRBUF_INIT;

static enum wt_status_format status_format = STATUS_FORMAT_UNSPECIFIED;

static int opt_parse_porcelain(const struct option *opt, const char *arg, int unset)
{
	enum wt_status_format *value = (enum wt_status_format *)opt->value;
	if (unset)
		*value = STATUS_FORMAT_NONE;
	else if (!arg)
		*value = STATUS_FORMAT_PORCELAIN;
	else if (!strcmp(arg, "v1") || !strcmp(arg, "1"))
		*value = STATUS_FORMAT_PORCELAIN;
	else if (!strcmp(arg, "v2") || !strcmp(arg, "2"))
		*value = STATUS_FORMAT_PORCELAIN_V2;
	else
		die("unsupported porcelain version '%s'", arg);

	return 0;
}

static int opt_parse_m(const struct option *opt, const char *arg, int unset)
{
	struct strbuf *buf = opt->value;
	if (unset) {
		have_option_m = 0;
		strbuf_setlen(buf, 0);
	} else {
		have_option_m = 1;
		if (buf->len)
			strbuf_addch(buf, '\n');
		strbuf_addstr(buf, arg);
		strbuf_complete_line(buf);
	}
	return 0;
}

static int opt_parse_rename_score(const struct option *opt, const char *arg, int unset)
{
	const char **value = opt->value;
	if (arg != NULL && *arg == '=')
		arg = arg + 1;

	*value = arg;
	return 0;
}

static void determine_whence(struct wt_status *s)
{
	if (file_exists(git_path_merge_head()))
		whence = FROM_MERGE;
	else if (file_exists(git_path_cherry_pick_head())) {
		whence = FROM_CHERRY_PICK;
		if (file_exists(git_path_seq_dir()))
			sequencer_in_use = 1;
	}
	else
		whence = FROM_COMMIT;
	if (s)
		s->whence = whence;
}

static void status_init_config(struct wt_status *s, config_fn_t fn)
{
	wt_status_prepare(s);
	init_diff_ui_defaults();
	git_config(fn, s);
	determine_whence(s);
	s->hints = advice_status_hints; /* must come after git_config() */
}

static void rollback_index_files(void)
{
	switch (commit_style) {
	case COMMIT_AS_IS:
		break; /* nothing to do */
	case COMMIT_NORMAL:
		rollback_lock_file(&index_lock);
		break;
	case COMMIT_PARTIAL:
		rollback_lock_file(&index_lock);
		rollback_lock_file(&false_lock);
		break;
	}
}

static int commit_index_files(void)
{
	int err = 0;

	switch (commit_style) {
	case COMMIT_AS_IS:
		break; /* nothing to do */
	case COMMIT_NORMAL:
		err = commit_lock_file(&index_lock);
		break;
	case COMMIT_PARTIAL:
		err = commit_lock_file(&index_lock);
		rollback_lock_file(&false_lock);
		break;
	}

	return err;
}

/*
 * Take a union of paths in the index and the named tree (typically, "HEAD"),
 * and return the paths that match the given pattern in list.
 */
static int list_paths(struct string_list *list, const char *with_tree,
		      const char *prefix, const struct pathspec *pattern)
{
	int i, ret;
	char *m;

	if (!pattern->nr)
		return 0;

	m = xcalloc(1, pattern->nr);

	if (with_tree) {
		char *max_prefix = common_prefix(pattern);
		overlay_tree_on_index(&the_index, with_tree, max_prefix);
		free(max_prefix);
	}

	for (i = 0; i < active_nr; i++) {
		const struct cache_entry *ce = active_cache[i];
		struct string_list_item *item;

		if (ce->ce_flags & CE_UPDATE)
			continue;
		if (!ce_path_match(ce, pattern, m))
			continue;
		item = string_list_insert(list, ce->name);
		if (ce_skip_worktree(ce))
			item->util = item; /* better a valid pointer than a fake one */
	}

	ret = report_path_error(m, pattern, prefix);
	free(m);
	return ret;
}

static void add_remove_files(struct string_list *list)
{
	int i;
	for (i = 0; i < list->nr; i++) {
		struct stat st;
		struct string_list_item *p = &(list->items[i]);

		/* p->util is skip-worktree */
		if (p->util)
			continue;

		if (!lstat(p->string, &st)) {
			if (add_to_cache(p->string, &st, 0))
				die(_("updating files failed"));
		} else
			remove_file_from_cache(p->string);
	}
}

static void create_base_index(const struct commit *current_head)
{
	struct tree *tree;
	struct unpack_trees_options opts;
	struct tree_desc t;

	if (!current_head) {
		discard_cache();
		return;
	}

	memset(&opts, 0, sizeof(opts));
	opts.head_idx = 1;
	opts.index_only = 1;
	opts.merge = 1;
	opts.src_index = &the_index;
	opts.dst_index = &the_index;

	opts.fn = oneway_merge;
	tree = parse_tree_indirect(&current_head->object.oid);
	if (!tree)
		die(_("failed to unpack HEAD tree object"));
	parse_tree(tree);
	init_tree_desc(&t, tree->buffer, tree->size);
	if (unpack_trees(1, &t, &opts))
		exit(128); /* We've already reported the error, finish dying */
}

static void refresh_cache_or_die(int refresh_flags)
{
	/*
	 * refresh_flags contains REFRESH_QUIET, so the only errors
	 * are for unmerged entries.
	 */
	if (refresh_cache(refresh_flags | REFRESH_IN_PORCELAIN))
		die_resolve_conflict("commit");
}

static const char *prepare_index(int argc, const char **argv, const char *prefix,
				 const struct commit *current_head, int is_status)
{
	struct string_list partial = STRING_LIST_INIT_DUP;
	struct pathspec pathspec;
	int refresh_flags = REFRESH_QUIET;
	const char *ret;

	if (is_status)
		refresh_flags |= REFRESH_UNMERGED;
	parse_pathspec(&pathspec, 0,
		       PATHSPEC_PREFER_FULL,
		       prefix, argv);

	if (read_cache_preload(&pathspec) < 0)
		die(_("index file corrupt"));

	if (interactive) {
		char *old_index_env = NULL;
		hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);

		refresh_cache_or_die(refresh_flags);

		if (write_locked_index(&the_index, &index_lock, 0))
			die(_("unable to create temporary index"));

		old_index_env = getenv(INDEX_ENVIRONMENT);
		setenv(INDEX_ENVIRONMENT, get_lock_file_path(&index_lock), 1);

		if (interactive_add(argc, argv, prefix, patch_interactive) != 0)
			die(_("interactive add failed"));

		if (old_index_env && *old_index_env)
			setenv(INDEX_ENVIRONMENT, old_index_env, 1);
		else
			unsetenv(INDEX_ENVIRONMENT);

		discard_cache();
		read_cache_from(get_lock_file_path(&index_lock));
		if (update_main_cache_tree(WRITE_TREE_SILENT) == 0) {
			if (reopen_lock_file(&index_lock) < 0)
				die(_("unable to write index file"));
			if (write_locked_index(&the_index, &index_lock, 0))
				die(_("unable to update temporary index"));
		} else
			warning(_("Failed to update main cache tree"));

		commit_style = COMMIT_NORMAL;
		ret = get_lock_file_path(&index_lock);
		goto out;
	}

	/*
	 * Non partial, non as-is commit.
	 *
	 * (1) get the real index;
	 * (2) update the_index as necessary;
	 * (3) write the_index out to the real index (still locked);
	 * (4) return the name of the locked index file.
	 *
	 * The caller should run hooks on the locked real index, and
	 * (A) if all goes well, commit the real index;
	 * (B) on failure, rollback the real index.
	 */
	if (all || (also && pathspec.nr)) {
		hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
		add_files_to_cache(also ? prefix : NULL, &pathspec, 0);
		refresh_cache_or_die(refresh_flags);
		update_main_cache_tree(WRITE_TREE_SILENT);
		if (write_locked_index(&the_index, &index_lock, 0))
			die(_("unable to write new_index file"));
		commit_style = COMMIT_NORMAL;
		ret = get_lock_file_path(&index_lock);
		goto out;
	}

	/*
	 * As-is commit.
	 *
	 * (1) return the name of the real index file.
	 *
	 * The caller should run hooks on the real index,
	 * and create commit from the_index.
	 * We still need to refresh the index here.
	 */
	if (!only && !pathspec.nr) {
		hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
		refresh_cache_or_die(refresh_flags);
		if (active_cache_changed
		    || !cache_tree_fully_valid(active_cache_tree))
			update_main_cache_tree(WRITE_TREE_SILENT);
		if (write_locked_index(&the_index, &index_lock,
				       COMMIT_LOCK | SKIP_IF_UNCHANGED))
			die(_("unable to write new_index file"));
		commit_style = COMMIT_AS_IS;
		ret = get_index_file();
		goto out;
	}

	/*
	 * A partial commit.
	 *
	 * (0) find the set of affected paths;
	 * (1) get lock on the real index file;
	 * (2) update the_index with the given paths;
	 * (3) write the_index out to the real index (still locked);
	 * (4) get lock on the false index file;
	 * (5) reset the_index from HEAD;
	 * (6) update the_index the same way as (2);
	 * (7) write the_index out to the false index file;
	 * (8) return the name of the false index file (still locked);
	 *
	 * The caller should run hooks on the locked false index, and
	 * create commit from it.  Then
	 * (A) if all goes well, commit the real index;
	 * (B) on failure, rollback the real index;
	 * In either case, rollback the false index.
	 */
	commit_style = COMMIT_PARTIAL;

	if (whence != FROM_COMMIT) {
		if (whence == FROM_MERGE)
			die(_("cannot do a partial commit during a merge."));
		else if (whence == FROM_CHERRY_PICK)
			die(_("cannot do a partial commit during a cherry-pick."));
	}

	if (list_paths(&partial, !current_head ? NULL : "HEAD", prefix, &pathspec))
		exit(1);

	discard_cache();
	if (read_cache() < 0)
		die(_("cannot read the index"));

	hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
	add_remove_files(&partial);
	refresh_cache(REFRESH_QUIET);
	update_main_cache_tree(WRITE_TREE_SILENT);
	if (write_locked_index(&the_index, &index_lock, 0))
		die(_("unable to write new_index file"));

	hold_lock_file_for_update(&false_lock,
				  git_path("next-index-%"PRIuMAX,
					   (uintmax_t) getpid()),
				  LOCK_DIE_ON_ERROR);

	create_base_index(current_head);
	add_remove_files(&partial);
	refresh_cache(REFRESH_QUIET);

	if (write_locked_index(&the_index, &false_lock, 0))
		die(_("unable to write temporary index file"));

	discard_cache();
	ret = get_lock_file_path(&false_lock);
	read_cache_from(ret);
out:
	string_list_clear(&partial, 0);
	clear_pathspec(&pathspec);
	return ret;
}

static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,
		      struct wt_status *s)
{
	struct object_id oid;

	if (s->relative_paths)
		s->prefix = prefix;

	if (amend) {
		s->amend = 1;
		s->reference = "HEAD^1";
	}
	s->verbose = verbose;
	s->index_file = index_file;
	s->fp = fp;
	s->nowarn = nowarn;
	s->is_initial = get_oid(s->reference, &oid) ? 1 : 0;
	if (!s->is_initial)
		hashcpy(s->sha1_commit, oid.hash);
	s->status_format = status_format;
	s->ignore_submodule_arg = ignore_submodule_arg;

	wt_status_collect(s);
	wt_status_print(s);

	return s->commitable;
}

static int is_a_merge(const struct commit *current_head)
{
	return !!(current_head->parents && current_head->parents->next);
}

static void assert_split_ident(struct ident_split *id, const struct strbuf *buf)
{
	if (split_ident_line(id, buf->buf, buf->len) || !id->date_begin)
		BUG("unable to parse our own ident: %s", buf->buf);
}

static void export_one(const char *var, const char *s, const char *e, int hack)
{
	struct strbuf buf = STRBUF_INIT;
	if (hack)
		strbuf_addch(&buf, hack);
	strbuf_addf(&buf, "%.*s", (int)(e - s), s);
	setenv(var, buf.buf, 1);
	strbuf_release(&buf);
}

static int parse_force_date(const char *in, struct strbuf *out)
{
	strbuf_addch(out, '@');

	if (parse_date(in, out) < 0) {
		int errors = 0;
		unsigned long t = approxidate_careful(in, &errors);
		if (errors)
			return -1;
		strbuf_addf(out, "%lu", t);
	}

	return 0;
}

static void set_ident_var(char **buf, char *val)
{
	free(*buf);
	*buf = val;
}

static void determine_author_info(struct strbuf *author_ident)
{
	char *name, *email, *date;
	struct ident_split author;

	name = xstrdup_or_null(getenv("GIT_AUTHOR_NAME"));
	email = xstrdup_or_null(getenv("GIT_AUTHOR_EMAIL"));
	date = xstrdup_or_null(getenv("GIT_AUTHOR_DATE"));

	if (author_message) {
		struct ident_split ident;
		size_t len;
		const char *a;

		a = find_commit_header(author_message_buffer, "author", &len);
		if (!a)
			die(_("commit '%s' lacks author header"), author_message);
		if (split_ident_line(&ident, a, len) < 0)
			die(_("commit '%s' has malformed author line"), author_message);

		set_ident_var(&name, xmemdupz(ident.name_begin, ident.name_end - ident.name_begin));
		set_ident_var(&email, xmemdupz(ident.mail_begin, ident.mail_end - ident.mail_begin));

		if (ident.date_begin) {
			struct strbuf date_buf = STRBUF_INIT;
			strbuf_addch(&date_buf, '@');
			strbuf_add(&date_buf, ident.date_begin, ident.date_end - ident.date_begin);
			strbuf_addch(&date_buf, ' ');
			strbuf_add(&date_buf, ident.tz_begin, ident.tz_end - ident.tz_begin);
			set_ident_var(&date, strbuf_detach(&date_buf, NULL));
		}
	}

	if (force_author) {
		struct ident_split ident;

		if (split_ident_line(&ident, force_author, strlen(force_author)) < 0)
			die(_("malformed --author parameter"));
		set_ident_var(&name, xmemdupz(ident.name_begin, ident.name_end - ident.name_begin));
		set_ident_var(&email, xmemdupz(ident.mail_begin, ident.mail_end - ident.mail_begin));
	}

	if (force_date) {
		struct strbuf date_buf = STRBUF_INIT;
		if (parse_force_date(force_date, &date_buf))
			die(_("invalid date format: %s"), force_date);
		set_ident_var(&date, strbuf_detach(&date_buf, NULL));
	}

	strbuf_addstr(author_ident, fmt_ident(name, email, date, IDENT_STRICT));
	assert_split_ident(&author, author_ident);
	export_one("GIT_AUTHOR_NAME", author.name_begin, author.name_end, 0);
	export_one("GIT_AUTHOR_EMAIL", author.mail_begin, author.mail_end, 0);
	export_one("GIT_AUTHOR_DATE", author.date_begin, author.tz_end, '@');
	free(name);
	free(email);
	free(date);
}

static int author_date_is_interesting(void)
{
	return author_message || force_date;
}

static void adjust_comment_line_char(const struct strbuf *sb)
{
	char candidates[] = "#;@!$%^&|:";
	char *candidate;
	const char *p;

	comment_line_char = candidates[0];
	if (!memchr(sb->buf, comment_line_char, sb->len))
		return;

	p = sb->buf;
	candidate = strchr(candidates, *p);
	if (candidate)
		*candidate = ' ';
	for (p = sb->buf; *p; p++) {
		if ((p[0] == '\n' || p[0] == '\r') && p[1]) {
			candidate = strchr(candidates, p[1]);
			if (candidate)
				*candidate = ' ';
		}
	}

	for (p = candidates; *p == ' '; p++)
		;
	if (!*p)
		die(_("unable to select a comment character that is not used\n"
		      "in the current commit message"));
	comment_line_char = *p;
}

static int prepare_to_commit(const char *index_file, const char *prefix,
			     struct commit *current_head,
			     struct wt_status *s,
			     struct strbuf *author_ident)
{
	struct stat statbuf;
	struct strbuf committer_ident = STRBUF_INIT;
	int commitable;
	struct strbuf sb = STRBUF_INIT;
	const char *hook_arg1 = NULL;
	const char *hook_arg2 = NULL;
	int clean_message_contents = (cleanup_mode != COMMIT_MSG_CLEANUP_NONE);
	int old_display_comment_prefix;

	/* This checks and barfs if author is badly specified */
	determine_author_info(author_ident);

	if (!no_verify && run_commit_hook(use_editor, index_file, "pre-commit", NULL))
		return 0;

	if (squash_message) {
		/*
		 * Insert the proper subject line before other commit
		 * message options add their content.
		 */
		if (use_message && !strcmp(use_message, squash_message))
			strbuf_addstr(&sb, "squash! ");
		else {
			struct pretty_print_context ctx = {0};
			struct commit *c;
			c = lookup_commit_reference_by_name(squash_message);
			if (!c)
				die(_("could not lookup commit %s"), squash_message);
			ctx.output_encoding = get_commit_output_encoding();
			format_commit_message(c, "squash! %s\n\n", &sb,
					      &ctx);
		}
	}

	if (have_option_m && !fixup_message) {
		strbuf_addbuf(&sb, &message);
		hook_arg1 = "message";
	} else if (logfile && !strcmp(logfile, "-")) {
		if (isatty(0))
			fprintf(stderr, _("(reading log message from standard input)\n"));
		if (strbuf_read(&sb, 0, 0) < 0)
			die_errno(_("could not read log from standard input"));
		hook_arg1 = "message";
	} else if (logfile) {
		if (strbuf_read_file(&sb, logfile, 0) < 0)
			die_errno(_("could not read log file '%s'"),
				  logfile);
		hook_arg1 = "message";
	} else if (use_message) {
		char *buffer;
		buffer = strstr(use_message_buffer, "\n\n");
		if (buffer)
			strbuf_addstr(&sb, skip_blank_lines(buffer + 2));
		hook_arg1 = "commit";
		hook_arg2 = use_message;
	} else if (fixup_message) {
		struct pretty_print_context ctx = {0};
		struct commit *commit;
		commit = lookup_commit_reference_by_name(fixup_message);
		if (!commit)
			die(_("could not lookup commit %s"), fixup_message);
		ctx.output_encoding = get_commit_output_encoding();
		format_commit_message(commit, "fixup! %s\n\n",
				      &sb, &ctx);
		if (have_option_m)
			strbuf_addbuf(&sb, &message);
		hook_arg1 = "message";
	} else if (!stat(git_path_merge_msg(), &statbuf)) {
		/*
		 * prepend SQUASH_MSG here if it exists and a
		 * "merge --squash" was originally performed
		 */
		if (!stat(git_path_squash_msg(), &statbuf)) {
			if (strbuf_read_file(&sb, git_path_squash_msg(), 0) < 0)
				die_errno(_("could not read SQUASH_MSG"));
			hook_arg1 = "squash";
		} else
			hook_arg1 = "merge";
		if (strbuf_read_file(&sb, git_path_merge_msg(), 0) < 0)
			die_errno(_("could not read MERGE_MSG"));
	} else if (!stat(git_path_squash_msg(), &statbuf)) {
		if (strbuf_read_file(&sb, git_path_squash_msg(), 0) < 0)
			die_errno(_("could not read SQUASH_MSG"));
		hook_arg1 = "squash";
	} else if (template_file) {
		if (strbuf_read_file(&sb, template_file, 0) < 0)
			die_errno(_("could not read '%s'"), template_file);
		hook_arg1 = "template";
		clean_message_contents = 0;
	}

	/*
	 * The remaining cases don't modify the template message, but
	 * just set the argument(s) to the prepare-commit-msg hook.
	 */
	else if (whence == FROM_MERGE)
		hook_arg1 = "merge";
	else if (whence == FROM_CHERRY_PICK) {
		hook_arg1 = "commit";
		hook_arg2 = "CHERRY_PICK_HEAD";
	}

	if (squash_message) {
		/*
		 * If squash_commit was used for the commit subject,
		 * then we're possibly hijacking other commit log options.
		 * Reset the hook args to tell the real story.
		 */
		hook_arg1 = "message";
		hook_arg2 = "";
	}

	s->fp = fopen_for_writing(git_path_commit_editmsg());
	if (s->fp == NULL)
		die_errno(_("could not open '%s'"), git_path_commit_editmsg());

	/* Ignore status.displayCommentPrefix: we do need comments in COMMIT_EDITMSG. */
	old_display_comment_prefix = s->display_comment_prefix;
	s->display_comment_prefix = 1;

	/*
	 * Most hints are counter-productive when the commit has
	 * already started.
	 */
	s->hints = 0;

	if (clean_message_contents)
		strbuf_stripspace(&sb, 0);

	if (signoff)
		append_signoff(&sb, ignore_non_trailer(sb.buf, sb.len), 0);

	if (fwrite(sb.buf, 1, sb.len, s->fp) < sb.len)
		die_errno(_("could not write commit template"));

	if (auto_comment_line_char)
		adjust_comment_line_char(&sb);
	strbuf_release(&sb);

	/* This checks if committer ident is explicitly given */
	strbuf_addstr(&committer_ident, git_committer_info(IDENT_STRICT));
	if (use_editor && include_status) {
		int ident_shown = 0;
		int saved_color_setting;
		struct ident_split ci, ai;

		if (whence != FROM_COMMIT) {
			if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
				wt_status_add_cut_line(s->fp);
			status_printf_ln(s, GIT_COLOR_NORMAL,
			    whence == FROM_MERGE
				? _("\n"
					"It looks like you may be committing a merge.\n"
					"If this is not correct, please remove the file\n"
					"	%s\n"
					"and try again.\n")
				: _("\n"
					"It looks like you may be committing a cherry-pick.\n"
					"If this is not correct, please remove the file\n"
					"	%s\n"
					"and try again.\n"),
				whence == FROM_MERGE ?
					git_path_merge_head() :
					git_path_cherry_pick_head());
		}

		fprintf(s->fp, "\n");
		if (cleanup_mode == COMMIT_MSG_CLEANUP_ALL)
			status_printf(s, GIT_COLOR_NORMAL,
				_("Please enter the commit message for your changes."
				  " Lines starting\nwith '%c' will be ignored, and an empty"
				  " message aborts the commit.\n"), comment_line_char);
		else if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS &&
			 whence == FROM_COMMIT)
			wt_status_add_cut_line(s->fp);
		else /* COMMIT_MSG_CLEANUP_SPACE, that is. */
			status_printf(s, GIT_COLOR_NORMAL,
				_("Please enter the commit message for your changes."
				  " Lines starting\n"
				  "with '%c' will be kept; you may remove them"
				  " yourself if you want to.\n"
				  "An empty message aborts the commit.\n"), comment_line_char);

		/*
		 * These should never fail because they come from our own
		 * fmt_ident. They may fail the sane_ident test, but we know
		 * that the name and mail pointers will at least be valid,
		 * which is enough for our tests and printing here.
		 */
		assert_split_ident(&ai, author_ident);
		assert_split_ident(&ci, &committer_ident);

		if (ident_cmp(&ai, &ci))
			status_printf_ln(s, GIT_COLOR_NORMAL,
				_("%s"
				"Author:    %.*s <%.*s>"),
				ident_shown++ ? "" : "\n",
				(int)(ai.name_end - ai.name_begin), ai.name_begin,
				(int)(ai.mail_end - ai.mail_begin), ai.mail_begin);

		if (author_date_is_interesting())
			status_printf_ln(s, GIT_COLOR_NORMAL,
				_("%s"
				"Date:      %s"),
				ident_shown++ ? "" : "\n",
				show_ident_date(&ai, DATE_MODE(NORMAL)));

		if (!committer_ident_sufficiently_given())
			status_printf_ln(s, GIT_COLOR_NORMAL,
				_("%s"
				"Committer: %.*s <%.*s>"),
				ident_shown++ ? "" : "\n",
				(int)(ci.name_end - ci.name_begin), ci.name_begin,
				(int)(ci.mail_end - ci.mail_begin), ci.mail_begin);

		status_printf_ln(s, GIT_COLOR_NORMAL, "%s", ""); /* Add new line for clarity */

		saved_color_setting = s->use_color;
		s->use_color = 0;
		commitable = run_status(s->fp, index_file, prefix, 1, s);
		s->use_color = saved_color_setting;
	} else {
		struct object_id oid;
		const char *parent = "HEAD";

		if (!active_nr && read_cache() < 0)
			die(_("Cannot read index"));

		if (amend)
			parent = "HEAD^1";

		if (get_oid(parent, &oid)) {
			int i, ita_nr = 0;

			for (i = 0; i < active_nr; i++)
				if (ce_intent_to_add(active_cache[i]))
					ita_nr++;
			commitable = active_nr - ita_nr > 0;
		} else {
			/*
			 * Unless the user did explicitly request a submodule
			 * ignore mode by passing a command line option we do
			 * not ignore any changed submodule SHA-1s when
			 * comparing index and parent, no matter what is
			 * configured. Otherwise we won't commit any
			 * submodules which were manually staged, which would
			 * be really confusing.
			 */
			struct diff_flags flags = DIFF_FLAGS_INIT;
			flags.override_submodule_config = 1;
			if (ignore_submodule_arg &&
			    !strcmp(ignore_submodule_arg, "all"))
				flags.ignore_submodules = 1;
			commitable = index_differs_from(parent, &flags, 1);
		}
	}
	strbuf_release(&committer_ident);

	fclose(s->fp);

	/*
	 * Reject an attempt to record a non-merge empty commit without
	 * explicit --allow-empty. In the cherry-pick case, it may be
	 * empty due to conflict resolution, which the user should okay.
	 */
	if (!commitable && whence != FROM_MERGE && !allow_empty &&
	    !(amend && is_a_merge(current_head))) {
		s->display_comment_prefix = old_display_comment_prefix;
		run_status(stdout, index_file, prefix, 0, s);
		if (amend)
			fputs(_(empty_amend_advice), stderr);
		else if (whence == FROM_CHERRY_PICK) {
			fputs(_(empty_cherry_pick_advice), stderr);
			if (!sequencer_in_use)
				fputs(_(empty_cherry_pick_advice_single), stderr);
			else
				fputs(_(empty_cherry_pick_advice_multi), stderr);
		}
		return 0;
	}

	if (!no_verify && find_hook("pre-commit")) {
		/*
		 * Re-read the index as pre-commit hook could have updated it,
		 * and write it out as a tree.  We must do this before we invoke
		 * the editor and after we invoke run_status above.
		 */
		discard_cache();
	}
	read_cache_from(index_file);

	if (update_main_cache_tree(0)) {
		error(_("Error building trees"));
		return 0;
	}

	if (run_commit_hook(use_editor, index_file, "prepare-commit-msg",
			    git_path_commit_editmsg(), hook_arg1, hook_arg2, NULL))
		return 0;

	if (use_editor) {
		struct argv_array env = ARGV_ARRAY_INIT;

		argv_array_pushf(&env, "GIT_INDEX_FILE=%s", index_file);
		if (launch_editor(git_path_commit_editmsg(), NULL, env.argv)) {
			fprintf(stderr,
			_("Please supply the message using either -m or -F option.\n"));
			exit(1);
		}
		argv_array_clear(&env);
	}

	if (!no_verify &&
	    run_commit_hook(use_editor, index_file, "commit-msg", git_path_commit_editmsg(), NULL)) {
		return 0;
	}

	return 1;
}

static const char *find_author_by_nickname(const char *name)
{
	struct rev_info revs;
	struct commit *commit;
	struct strbuf buf = STRBUF_INIT;
	struct string_list mailmap = STRING_LIST_INIT_NODUP;
	const char *av[20];
	int ac = 0;

	init_revisions(&revs, NULL);
	strbuf_addf(&buf, "--author=%s", name);
	av[++ac] = "--all";
	av[++ac] = "-i";
	av[++ac] = buf.buf;
	av[++ac] = NULL;
	setup_revisions(ac, av, &revs, NULL);
	revs.mailmap = &mailmap;
	read_mailmap(revs.mailmap, NULL);

	if (prepare_revision_walk(&revs))
		die(_("revision walk setup failed"));
	commit = get_revision(&revs);
	if (commit) {
		struct pretty_print_context ctx = {0};
		ctx.date_mode.type = DATE_NORMAL;
		strbuf_release(&buf);
		format_commit_message(commit, "%aN <%aE>", &buf, &ctx);
		clear_mailmap(&mailmap);
		return strbuf_detach(&buf, NULL);
	}
	die(_("--author '%s' is not 'Name <email>' and matches no existing author"), name);
}

static void handle_ignored_arg(struct wt_status *s)
{
	if (!ignored_arg)
		; /* default already initialized */
	else if (!strcmp(ignored_arg, "traditional"))
		s->show_ignored_mode = SHOW_TRADITIONAL_IGNORED;
	else if (!strcmp(ignored_arg, "no"))
		s->show_ignored_mode = SHOW_NO_IGNORED;
	else if (!strcmp(ignored_arg, "matching"))
		s->show_ignored_mode = SHOW_MATCHING_IGNORED;
	else
		die(_("Invalid ignored mode '%s'"), ignored_arg);
}

static void handle_untracked_files_arg(struct wt_status *s)
{
	if (!untracked_files_arg)
		; /* default already initialized */
	else if (!strcmp(untracked_files_arg, "no"))
		s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
	else if (!strcmp(untracked_files_arg, "normal"))
		s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
	else if (!strcmp(untracked_files_arg, "all"))
		s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
	else
		die(_("Invalid untracked files mode '%s'"), untracked_files_arg);
}

static const char *read_commit_message(const char *name)
{
	const char *out_enc;
	struct commit *commit;

	commit = lookup_commit_reference_by_name(name);
	if (!commit)
		die(_("could not lookup commit %s"), name);
	out_enc = get_commit_output_encoding();
	return logmsg_reencode(commit, NULL, out_enc);
}

/*
 * Enumerate what needs to be propagated when --porcelain
 * is not in effect here.
 */
static struct status_deferred_config {
	enum wt_status_format status_format;
	int show_branch;
} status_deferred_config = {
	STATUS_FORMAT_UNSPECIFIED,
	-1 /* unspecified */
};

static void finalize_deferred_config(struct wt_status *s)
{
	int use_deferred_config = (status_format != STATUS_FORMAT_PORCELAIN &&
				   status_format != STATUS_FORMAT_PORCELAIN_V2 &&
				   !s->null_termination);

	if (s->null_termination) {
		if (status_format == STATUS_FORMAT_NONE ||
		    status_format == STATUS_FORMAT_UNSPECIFIED)
			status_format = STATUS_FORMAT_PORCELAIN;
		else if (status_format == STATUS_FORMAT_LONG)
			die(_("--long and -z are incompatible"));
	}

	if (use_deferred_config && status_format == STATUS_FORMAT_UNSPECIFIED)
		status_format = status_deferred_config.status_format;
	if (status_format == STATUS_FORMAT_UNSPECIFIED)
		status_format = STATUS_FORMAT_NONE;

	if (use_deferred_config && s->show_branch < 0)
		s->show_branch = status_deferred_config.show_branch;
	if (s->show_branch < 0)
		s->show_branch = 0;

	if (s->ahead_behind_flags == AHEAD_BEHIND_UNSPECIFIED)
		s->ahead_behind_flags = AHEAD_BEHIND_FULL;
}

static int parse_and_validate_options(int argc, const char *argv[],
				      const struct option *options,
				      const char * const usage[],
				      const char *prefix,
				      struct commit *current_head,
				      struct wt_status *s)
{
	int f = 0;

	argc = parse_options(argc, argv, prefix, options, usage, 0);
	finalize_deferred_config(s);

	if (force_author && !strchr(force_author, '>'))
		force_author = find_author_by_nickname(force_author);

	if (force_author && renew_authorship)
		die(_("Using both --reset-author and --author does not make sense"));

	if (logfile || have_option_m || use_message || fixup_message)
		use_editor = 0;
	if (0 <= edit_flag)
		use_editor = edit_flag;

	/* Sanity check options */
	if (amend && !current_head)
		die(_("You have nothing to amend."));
	if (amend && whence != FROM_COMMIT) {
		if (whence == FROM_MERGE)
			die(_("You are in the middle of a merge -- cannot amend."));
		else if (whence == FROM_CHERRY_PICK)
			die(_("You are in the middle of a cherry-pick -- cannot amend."));
	}
	if (fixup_message && squash_message)
		die(_("Options --squash and --fixup cannot be used together"));
	if (use_message)
		f++;
	if (edit_message)
		f++;
	if (fixup_message)
		f++;
	if (logfile)
		f++;
	if (f > 1)
		die(_("Only one of -c/-C/-F/--fixup can be used."));
	if (have_option_m && (edit_message || use_message || logfile))
		die((_("Option -m cannot be combined with -c/-C/-F.")));
	if (f || have_option_m)
		template_file = NULL;
	if (edit_message)
		use_message = edit_message;
	if (amend && !use_message && !fixup_message)
		use_message = "HEAD";
	if (!use_message && whence != FROM_CHERRY_PICK && renew_authorship)
		die(_("--reset-author can be used only with -C, -c or --amend."));
	if (use_message) {
		use_message_buffer = read_commit_message(use_message);
		if (!renew_authorship) {
			author_message = use_message;
			author_message_buffer = use_message_buffer;
		}
	}
	if (whence == FROM_CHERRY_PICK && !renew_authorship) {
		author_message = "CHERRY_PICK_HEAD";
		author_message_buffer = read_commit_message(author_message);
	}

	if (patch_interactive)
		interactive = 1;

	if (also + only + all + interactive > 1)
		die(_("Only one of --include/--only/--all/--interactive/--patch can be used."));
	if (argc == 0 && (also || (only && !amend && !allow_empty)))
		die(_("No paths with --include/--only does not make sense."));
	if (!cleanup_arg || !strcmp(cleanup_arg, "default"))
		cleanup_mode = use_editor ? COMMIT_MSG_CLEANUP_ALL :
					    COMMIT_MSG_CLEANUP_SPACE;
	else if (!strcmp(cleanup_arg, "verbatim"))
		cleanup_mode = COMMIT_MSG_CLEANUP_NONE;
	else if (!strcmp(cleanup_arg, "whitespace"))
		cleanup_mode = COMMIT_MSG_CLEANUP_SPACE;
	else if (!strcmp(cleanup_arg, "strip"))
		cleanup_mode = COMMIT_MSG_CLEANUP_ALL;
	else if (!strcmp(cleanup_arg, "scissors"))
		cleanup_mode = use_editor ? COMMIT_MSG_CLEANUP_SCISSORS :
					    COMMIT_MSG_CLEANUP_SPACE;
	else
		die(_("Invalid cleanup mode %s"), cleanup_arg);

	handle_untracked_files_arg(s);

	if (all && argc > 0)
		die(_("Paths with -a does not make sense."));

	if (status_format != STATUS_FORMAT_NONE)
		dry_run = 1;

	return argc;
}

static int dry_run_commit(int argc, const char **argv, const char *prefix,
			  const struct commit *current_head, struct wt_status *s)
{
	int commitable;
	const char *index_file;

	index_file = prepare_index(argc, argv, prefix, current_head, 1);
	commitable = run_status(stdout, index_file, prefix, 0, s);
	rollback_index_files();

	return commitable ? 0 : 1;
}

define_list_config_array_extra(color_status_slots, {"added"});

static int parse_status_slot(const char *slot)
{
	if (!strcasecmp(slot, "added"))
		return WT_STATUS_UPDATED;

	return LOOKUP_CONFIG(color_status_slots, slot);
}

static int git_status_config(const char *k, const char *v, void *cb)
{
	struct wt_status *s = cb;
	const char *slot_name;

	if (starts_with(k, "column."))
		return git_column_config(k, v, "status", &s->colopts);
	if (!strcmp(k, "status.submodulesummary")) {
		int is_bool;
		s->submodule_summary = git_config_bool_or_int(k, v, &is_bool);
		if (is_bool && s->submodule_summary)
			s->submodule_summary = -1;
		return 0;
	}
	if (!strcmp(k, "status.short")) {
		if (git_config_bool(k, v))
			status_deferred_config.status_format = STATUS_FORMAT_SHORT;
		else
			status_deferred_config.status_format = STATUS_FORMAT_NONE;
		return 0;
	}
	if (!strcmp(k, "status.branch")) {
		status_deferred_config.show_branch = git_config_bool(k, v);
		return 0;
	}
	if (!strcmp(k, "status.showstash")) {
		s->show_stash = git_config_bool(k, v);
		return 0;
	}
	if (!strcmp(k, "status.color") || !strcmp(k, "color.status")) {
		s->use_color = git_config_colorbool(k, v);
		return 0;
	}
	if (!strcmp(k, "status.displaycommentprefix")) {
		s->display_comment_prefix = git_config_bool(k, v);
		return 0;
	}
	if (skip_prefix(k, "status.color.", &slot_name) ||
	    skip_prefix(k, "color.status.", &slot_name)) {
		int slot = parse_status_slot(slot_name);
		if (slot < 0)
			return 0;
		if (!v)
			return config_error_nonbool(k);
		return color_parse(v, s->color_palette[slot]);
	}
	if (!strcmp(k, "status.relativepaths")) {
		s->relative_paths = git_config_bool(k, v);
		return 0;
	}
	if (!strcmp(k, "status.showuntrackedfiles")) {
		if (!v)
			return config_error_nonbool(k);
		else if (!strcmp(v, "no"))
			s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
		else if (!strcmp(v, "normal"))
			s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
		else if (!strcmp(v, "all"))
			s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
		else
			return error(_("Invalid untracked files mode '%s'"), v);
		return 0;
	}
	if (!strcmp(k, "diff.renamelimit")) {
		if (s->rename_limit == -1)
			s->rename_limit = git_config_int(k, v);
		return 0;
	}
	if (!strcmp(k, "status.renamelimit")) {
		s->rename_limit = git_config_int(k, v);
		return 0;
	}
	if (!strcmp(k, "diff.renames")) {
		if (s->detect_rename == -1)
			s->detect_rename = git_config_rename(k, v);
		return 0;
	}
	if (!strcmp(k, "status.renames")) {
		s->detect_rename = git_config_rename(k, v);
		return 0;
	}
	return git_diff_ui_config(k, v, NULL);
}

int cmd_status(int argc, const char **argv, const char *prefix)
{
	static int no_renames = -1;
	static const char *rename_score_arg = (const char *)-1;
	static struct wt_status s;
	int fd;
	struct object_id oid;
	static struct option builtin_status_options[] = {
		OPT__VERBOSE(&verbose, N_("be verbose")),
		OPT_SET_INT('s', "short", &status_format,
			    N_("show status concisely"), STATUS_FORMAT_SHORT),
		OPT_BOOL('b', "branch", &s.show_branch,
			 N_("show branch information")),
		OPT_BOOL(0, "show-stash", &s.show_stash,
			 N_("show stash information")),
		OPT_BOOL(0, "ahead-behind", &s.ahead_behind_flags,
			 N_("compute full ahead/behind values")),
		{ OPTION_CALLBACK, 0, "porcelain", &status_format,
		  N_("version"), N_("machine-readable output"),
		  PARSE_OPT_OPTARG, opt_parse_porcelain },
		OPT_SET_INT(0, "long", &status_format,
			    N_("show status in long format (default)"),
			    STATUS_FORMAT_LONG),
		OPT_BOOL('z', "null", &s.null_termination,
			 N_("terminate entries with NUL")),
		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg,
		  N_("mode"),
		  N_("show untracked files, optional modes: all, normal, no. (Default: all)"),
		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
		{ OPTION_STRING, 0, "ignored", &ignored_arg,
		  N_("mode"),
		  N_("show ignored files, optional modes: traditional, matching, no. (Default: traditional)"),
		  PARSE_OPT_OPTARG, NULL, (intptr_t)"traditional" },
		{ OPTION_STRING, 0, "ignore-submodules", &ignore_submodule_arg, N_("when"),
		  N_("ignore changes to submodules, optional when: all, dirty, untracked. (Default: all)"),
		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
		OPT_COLUMN(0, "column", &s.colopts, N_("list untracked files in columns")),
		OPT_BOOL(0, "no-renames", &no_renames, N_("do not detect renames")),
		{ OPTION_CALLBACK, 'M', "find-renames", &rename_score_arg,
		  N_("n"), N_("detect renames, optionally set similarity index"),
		  PARSE_OPT_OPTARG, opt_parse_rename_score },
		OPT_END(),
	};

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage_with_options(builtin_status_usage, builtin_status_options);

	status_init_config(&s, git_status_config);
	argc = parse_options(argc, argv, prefix,
			     builtin_status_options,
			     builtin_status_usage, 0);
	finalize_colopts(&s.colopts, -1);
	finalize_deferred_config(&s);

	handle_untracked_files_arg(&s);
	handle_ignored_arg(&s);

	if (s.show_ignored_mode == SHOW_MATCHING_IGNORED &&
	    s.show_untracked_files == SHOW_NO_UNTRACKED_FILES)
		die(_("Unsupported combination of ignored and untracked-files arguments"));

	parse_pathspec(&s.pathspec, 0,
		       PATHSPEC_PREFER_FULL,
		       prefix, argv);

	read_cache_preload(&s.pathspec);
	refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, &s.pathspec, NULL, NULL);

	if (use_optional_locks())
		fd = hold_locked_index(&index_lock, 0);
	else
		fd = -1;

	s.is_initial = get_oid(s.reference, &oid) ? 1 : 0;
	if (!s.is_initial)
		hashcpy(s.sha1_commit, oid.hash);

	s.ignore_submodule_arg = ignore_submodule_arg;
	s.status_format = status_format;
	s.verbose = verbose;
	if (no_renames != -1)
		s.detect_rename = !no_renames;
	if ((intptr_t)rename_score_arg != -1) {
		if (s.detect_rename < DIFF_DETECT_RENAME)
			s.detect_rename = DIFF_DETECT_RENAME;
		if (rename_score_arg)
			s.rename_score = parse_rename_score(&rename_score_arg);
	}

	wt_status_collect(&s);

	if (0 <= fd)
		update_index_if_able(&the_index, &index_lock);

	if (s.relative_paths)
		s.prefix = prefix;

	wt_status_print(&s);
	return 0;
}

static int git_commit_config(const char *k, const char *v, void *cb)
{
	struct wt_status *s = cb;
	int status;

	if (!strcmp(k, "commit.template"))
		return git_config_pathname(&template_file, k, v);
	if (!strcmp(k, "commit.status")) {
		include_status = git_config_bool(k, v);
		return 0;
	}
	if (!strcmp(k, "commit.cleanup"))
		return git_config_string(&cleanup_arg, k, v);
	if (!strcmp(k, "commit.gpgsign")) {
		sign_commit = git_config_bool(k, v) ? "" : NULL;
		return 0;
	}
	if (!strcmp(k, "commit.verbose")) {
		int is_bool;
		config_commit_verbose = git_config_bool_or_int(k, v, &is_bool);
		return 0;
	}

	status = git_gpg_config(k, v, NULL);
	if (status)
		return status;
	return git_status_config(k, v, s);
}

int run_commit_hook(int editor_is_used, const char *index_file, const char *name, ...)
{
	struct argv_array hook_env = ARGV_ARRAY_INIT;
	va_list args;
	int ret;

	argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", index_file);

	/*
	 * Let the hook know that no editor will be launched.
	 */
	if (!editor_is_used)
		argv_array_push(&hook_env, "GIT_EDITOR=:");

	va_start(args, name);
	ret = run_hook_ve(hook_env.argv,name, args);
	va_end(args);
	argv_array_clear(&hook_env);

	return ret;
}

int cmd_commit(int argc, const char **argv, const char *prefix)
{
	const char *argv_gc_auto[] = {"gc", "--auto", NULL};
	static struct wt_status s;
	static struct option builtin_commit_options[] = {
		OPT__QUIET(&quiet, N_("suppress summary after successful commit")),
		OPT__VERBOSE(&verbose, N_("show diff in commit message template")),

		OPT_GROUP(N_("Commit message options")),
		OPT_FILENAME('F', "file", &logfile, N_("read message from file")),
		OPT_STRING(0, "author", &force_author, N_("author"), N_("override author for commit")),
		OPT_STRING(0, "date", &force_date, N_("date"), N_("override date for commit")),
		OPT_CALLBACK('m', "message", &message, N_("message"), N_("commit message"), opt_parse_m),
		OPT_STRING('c', "reedit-message", &edit_message, N_("commit"), N_("reuse and edit message from specified commit")),
		OPT_STRING('C', "reuse-message", &use_message, N_("commit"), N_("reuse message from specified commit")),
		OPT_STRING(0, "fixup", &fixup_message, N_("commit"), N_("use autosquash formatted message to fixup specified commit")),
		OPT_STRING(0, "squash", &squash_message, N_("commit"), N_("use autosquash formatted message to squash specified commit")),
		OPT_BOOL(0, "reset-author", &renew_authorship, N_("the commit is authored by me now (used with -C/-c/--amend)")),
		OPT_BOOL('s', "signoff", &signoff, N_("add Signed-off-by:")),
		OPT_FILENAME('t', "template", &template_file, N_("use specified template file")),
		OPT_BOOL('e', "edit", &edit_flag, N_("force edit of commit")),
		OPT_STRING(0, "cleanup", &cleanup_arg, N_("default"), N_("how to strip spaces and #comments from message")),
		OPT_BOOL(0, "status", &include_status, N_("include status in commit message template")),
		{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
		  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
		/* end commit message options */

		OPT_GROUP(N_("Commit contents options")),
		OPT_BOOL('a', "all", &all, N_("commit all changed files")),
		OPT_BOOL('i', "include", &also, N_("add specified files to index for commit")),
		OPT_BOOL(0, "interactive", &interactive, N_("interactively add files")),
		OPT_BOOL('p', "patch", &patch_interactive, N_("interactively add changes")),
		OPT_BOOL('o', "only", &only, N_("commit only specified files")),
		OPT_BOOL('n', "no-verify", &no_verify, N_("bypass pre-commit and commit-msg hooks")),
		OPT_BOOL(0, "dry-run", &dry_run, N_("show what would be committed")),
		OPT_SET_INT(0, "short", &status_format, N_("show status concisely"),
			    STATUS_FORMAT_SHORT),
		OPT_BOOL(0, "branch", &s.show_branch, N_("show branch information")),
		OPT_BOOL(0, "ahead-behind", &s.ahead_behind_flags,
			 N_("compute full ahead/behind values")),
		OPT_SET_INT(0, "porcelain", &status_format,
			    N_("machine-readable output"), STATUS_FORMAT_PORCELAIN),
		OPT_SET_INT(0, "long", &status_format,
			    N_("show status in long format (default)"),
			    STATUS_FORMAT_LONG),
		OPT_BOOL('z', "null", &s.null_termination,
			 N_("terminate entries with NUL")),
		OPT_BOOL(0, "amend", &amend, N_("amend previous commit")),
		OPT_BOOL(0, "no-post-rewrite", &no_post_rewrite, N_("bypass post-rewrite hook")),
		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, N_("mode"), N_("show untracked files, optional modes: all, normal, no. (Default: all)"), PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
		/* end commit contents options */

		OPT_HIDDEN_BOOL(0, "allow-empty", &allow_empty,
				N_("ok to record an empty change")),
		OPT_HIDDEN_BOOL(0, "allow-empty-message", &allow_empty_message,
				N_("ok to record a change with an empty message")),

		OPT_END()
	};

	struct strbuf sb = STRBUF_INIT;
	struct strbuf author_ident = STRBUF_INIT;
	const char *index_file, *reflog_msg;
	struct object_id oid;
	struct commit_list *parents = NULL;
	struct stat statbuf;
	struct commit *current_head = NULL;
	struct commit_extra_header *extra = NULL;
	struct strbuf err = STRBUF_INIT;

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage_with_options(builtin_commit_usage, builtin_commit_options);

	status_init_config(&s, git_commit_config);
	s.commit_template = 1;
	status_format = STATUS_FORMAT_NONE; /* Ignore status.short */
	s.colopts = 0;

	if (get_oid("HEAD", &oid))
		current_head = NULL;
	else {
		current_head = lookup_commit_or_die(&oid, "HEAD");
		if (parse_commit(current_head))
			die(_("could not parse HEAD commit"));
	}
	verbose = -1; /* unspecified */
	argc = parse_and_validate_options(argc, argv, builtin_commit_options,
					  builtin_commit_usage,
					  prefix, current_head, &s);
	if (verbose == -1)
		verbose = (config_commit_verbose < 0) ? 0 : config_commit_verbose;

	if (dry_run)
		return dry_run_commit(argc, argv, prefix, current_head, &s);
	index_file = prepare_index(argc, argv, prefix, current_head, 0);

	/* Set up everything for writing the commit object.  This includes
	   running hooks, writing the trees, and interacting with the user.  */
	if (!prepare_to_commit(index_file, prefix,
			       current_head, &s, &author_ident)) {
		rollback_index_files();
		return 1;
	}

	/* Determine parents */
	reflog_msg = getenv("GIT_REFLOG_ACTION");
	if (!current_head) {
		if (!reflog_msg)
			reflog_msg = "commit (initial)";
	} else if (amend) {
		if (!reflog_msg)
			reflog_msg = "commit (amend)";
		parents = copy_commit_list(current_head->parents);
	} else if (whence == FROM_MERGE) {
		struct strbuf m = STRBUF_INIT;
		FILE *fp;
		int allow_fast_forward = 1;
		struct commit_list **pptr = &parents;

		if (!reflog_msg)
			reflog_msg = "commit (merge)";
		pptr = commit_list_append(current_head, pptr);
		fp = xfopen(git_path_merge_head(), "r");
		while (strbuf_getline_lf(&m, fp) != EOF) {
			struct commit *parent;

			parent = get_merge_parent(m.buf);
			if (!parent)
				die(_("Corrupt MERGE_HEAD file (%s)"), m.buf);
			pptr = commit_list_append(parent, pptr);
		}
		fclose(fp);
		strbuf_release(&m);
		if (!stat(git_path_merge_mode(), &statbuf)) {
			if (strbuf_read_file(&sb, git_path_merge_mode(), 0) < 0)
				die_errno(_("could not read MERGE_MODE"));
			if (!strcmp(sb.buf, "no-ff"))
				allow_fast_forward = 0;
		}
		if (allow_fast_forward)
			reduce_heads_replace(&parents);
	} else {
		if (!reflog_msg)
			reflog_msg = (whence == FROM_CHERRY_PICK)
					? "commit (cherry-pick)"
					: "commit";
		commit_list_insert(current_head, &parents);
	}

	/* Finally, get the commit message */
	strbuf_reset(&sb);
	if (strbuf_read_file(&sb, git_path_commit_editmsg(), 0) < 0) {
		int saved_errno = errno;
		rollback_index_files();
		die(_("could not read commit message: %s"), strerror(saved_errno));
	}

	if (verbose || /* Truncate the message just before the diff, if any. */
	    cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
		strbuf_setlen(&sb, wt_status_locate_end(sb.buf, sb.len));
	if (cleanup_mode != COMMIT_MSG_CLEANUP_NONE)
		strbuf_stripspace(&sb, cleanup_mode == COMMIT_MSG_CLEANUP_ALL);

	if (message_is_empty(&sb, cleanup_mode) && !allow_empty_message) {
		rollback_index_files();
		fprintf(stderr, _("Aborting commit due to empty commit message.\n"));
		exit(1);
	}
	if (template_untouched(&sb, template_file, cleanup_mode) && !allow_empty_message) {
		rollback_index_files();
		fprintf(stderr, _("Aborting commit; you did not edit the message.\n"));
		exit(1);
	}

	if (amend) {
		const char *exclude_gpgsig[2] = { "gpgsig", NULL };
		extra = read_commit_extra_headers(current_head, exclude_gpgsig);
	} else {
		struct commit_extra_header **tail = &extra;
		append_merge_tag_headers(parents, &tail);
	}

	if (commit_tree_extended(sb.buf, sb.len, &active_cache_tree->oid,
				 parents, &oid, author_ident.buf, sign_commit,
				 extra)) {
		rollback_index_files();
		die(_("failed to write commit object"));
	}
	strbuf_release(&author_ident);
	free_commit_extra_headers(extra);

	if (update_head_with_reflog(current_head, &oid, reflog_msg, &sb,
				    &err)) {
		rollback_index_files();
		die("%s", err.buf);
	}

	unlink(git_path_cherry_pick_head());
	unlink(git_path_revert_head());
	unlink(git_path_merge_head());
	unlink(git_path_merge_msg());
	unlink(git_path_merge_mode());
	unlink(git_path_squash_msg());

	if (commit_index_files())
		die (_("Repository has been updated, but unable to write\n"
		     "new_index file. Check that disk is not full and quota is\n"
		     "not exceeded, and then \"git reset HEAD\" to recover."));

	rerere(0);
	run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
	run_commit_hook(use_editor, get_index_file(), "post-commit", NULL);
	if (amend && !no_post_rewrite) {
		commit_post_rewrite(current_head, &oid);
	}
	if (!quiet) {
		unsigned int flags = 0;

		if (!current_head)
			flags |= SUMMARY_INITIAL_COMMIT;
		if (author_date_is_interesting())
			flags |= SUMMARY_SHOW_AUTHOR_DATE;
		print_commit_summary(prefix, &oid, flags);
	}

	UNLEAK(err);
	UNLEAK(sb);
	return 0;
}