/*
 * Builtin "git log" and related commands (show, whatchanged)
 *
 * (C) Copyright 2006 Linus Torvalds
 *		 2006 Junio Hamano
 */
#define USE_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
#include "config.h"
#include "refs.h"
#include "object-store.h"
#include "color.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "log-tree.h"
#include "builtin.h"
#include "tag.h"
#include "reflog-walk.h"
#include "patch-ids.h"
#include "run-command.h"
#include "shortlog.h"
#include "remote.h"
#include "string-list.h"
#include "parse-options.h"
#include "line-log.h"
#include "branch.h"
#include "streaming.h"
#include "version.h"
#include "mailmap.h"
#include "gpg-interface.h"
#include "progress.h"
#include "commit-slab.h"
#include "repository.h"
#include "commit-reach.h"
#include "interdiff.h"
#include "range-diff.h"

#define MAIL_DEFAULT_WRAP 72

/* Set a default date-time format for git log ("log.date" config variable) */
static const char *default_date_mode = NULL;

static int default_abbrev_commit;
static int default_show_root = 1;
static int default_follow;
static int default_show_signature;
static int decoration_style;
static int decoration_given;
static int use_mailmap_config = -1;
static const char *fmt_patch_subject_prefix = "PATCH";
static const char *fmt_pretty;

static const char * const builtin_log_usage[] = {
	N_("git log [<options>] [<revision-range>] [[--] <path>...]"),
	N_("git show [<options>] <object>..."),
	NULL
};

struct line_opt_callback_data {
	struct rev_info *rev;
	const char *prefix;
	struct string_list args;
};

static int session_is_interactive(void)
{
	return isatty(1) || pager_in_use();
}

static int auto_decoration_style(void)
{
	return session_is_interactive() ? DECORATE_SHORT_REFS : 0;
}

static int parse_decoration_style(const char *value)
{
	switch (git_parse_maybe_bool(value)) {
	case 1:
		return DECORATE_SHORT_REFS;
	case 0:
		return 0;
	default:
		break;
	}
	if (!strcmp(value, "full"))
		return DECORATE_FULL_REFS;
	else if (!strcmp(value, "short"))
		return DECORATE_SHORT_REFS;
	else if (!strcmp(value, "auto"))
		return auto_decoration_style();
	/*
	 * Please update _git_log() in git-completion.bash when you
	 * add new decoration styles.
	 */
	return -1;
}

static int decorate_callback(const struct option *opt, const char *arg, int unset)
{
	if (unset)
		decoration_style = 0;
	else if (arg)
		decoration_style = parse_decoration_style(arg);
	else
		decoration_style = DECORATE_SHORT_REFS;

	if (decoration_style < 0)
		die(_("invalid --decorate option: %s"), arg);

	decoration_given = 1;

	return 0;
}

static int log_line_range_callback(const struct option *option, const char *arg, int unset)
{
	struct line_opt_callback_data *data = option->value;

	BUG_ON_OPT_NEG(unset);

	if (!arg)
		return -1;

	data->rev->line_level_traverse = 1;
	string_list_append(&data->args, arg);

	return 0;
}

static void init_log_defaults(void)
{
	init_grep_defaults(the_repository);
	init_diff_ui_defaults();

	decoration_style = auto_decoration_style();
}

static void cmd_log_init_defaults(struct rev_info *rev)
{
	if (fmt_pretty)
		get_commit_format(fmt_pretty, rev);
	if (default_follow)
		rev->diffopt.flags.default_follow_renames = 1;
	rev->verbose_header = 1;
	rev->diffopt.flags.recursive = 1;
	rev->diffopt.stat_width = -1; /* use full terminal width */
	rev->diffopt.stat_graph_width = -1; /* respect statGraphWidth config */
	rev->abbrev_commit = default_abbrev_commit;
	rev->show_root_diff = default_show_root;
	rev->subject_prefix = fmt_patch_subject_prefix;
	rev->show_signature = default_show_signature;
	rev->diffopt.flags.allow_textconv = 1;

	if (default_date_mode)
		parse_date_format(default_date_mode, &rev->date_mode);
}

static char warn_unspecified_mailmap_msg[] =
N_("log.mailmap is not set; its implicit value will change in an\n"
   "upcoming release. To squelch this message and preserve current\n"
   "behaviour, set the log.mailmap configuration value to false.\n"
   "\n"
   "To squelch this message and adopt the new behaviour now, set the\n"
   "log.mailmap configuration value to true.\n"
   "\n"
   "See 'git help config' and search for 'log.mailmap' for further information.");

static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
			 struct rev_info *rev, struct setup_revision_opt *opt)
{
	struct userformat_want w;
	int quiet = 0, source = 0, mailmap = 0;
	static struct line_opt_callback_data line_cb = {NULL, NULL, STRING_LIST_INIT_DUP};
	static struct string_list decorate_refs_exclude = STRING_LIST_INIT_NODUP;
	static struct string_list decorate_refs_include = STRING_LIST_INIT_NODUP;
	struct decoration_filter decoration_filter = {&decorate_refs_include,
						      &decorate_refs_exclude};
	static struct revision_sources revision_sources;

	const struct option builtin_log_options[] = {
		OPT__QUIET(&quiet, N_("suppress diff output")),
		OPT_BOOL(0, "source", &source, N_("show source")),
		OPT_BOOL(0, "use-mailmap", &mailmap, N_("Use mail map file")),
		OPT_STRING_LIST(0, "decorate-refs", &decorate_refs_include,
				N_("pattern"), N_("only decorate refs that match <pattern>")),
		OPT_STRING_LIST(0, "decorate-refs-exclude", &decorate_refs_exclude,
				N_("pattern"), N_("do not decorate refs that match <pattern>")),
		{ OPTION_CALLBACK, 0, "decorate", NULL, NULL, N_("decorate options"),
		  PARSE_OPT_OPTARG, decorate_callback},
		OPT_CALLBACK('L', NULL, &line_cb, "n,m:file",
			     N_("Process line range n,m in file, counting from 1"),
			     log_line_range_callback),
		OPT_END()
	};

	line_cb.rev = rev;
	line_cb.prefix = prefix;

	mailmap = use_mailmap_config;
	argc = parse_options(argc, argv, prefix,
			     builtin_log_options, builtin_log_usage,
			     PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
			     PARSE_OPT_KEEP_DASHDASH);

	if (quiet)
		rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
	argc = setup_revisions(argc, argv, rev, opt);

	/* Any arguments at this point are not recognized */
	if (argc > 1)
		die(_("unrecognized argument: %s"), argv[1]);

	memset(&w, 0, sizeof(w));
	userformat_find_requirements(NULL, &w);

	if (mailmap < 0) {
		if (session_is_interactive() && !rev->pretty_given)
			warning("%s\n", _(warn_unspecified_mailmap_msg));

		mailmap = 0;
	}

	if (!rev->show_notes_given && (!rev->pretty_given || w.notes))
		rev->show_notes = 1;
	if (rev->show_notes)
		init_display_notes(&rev->notes_opt);

	if ((rev->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
	    rev->diffopt.filter || rev->diffopt.flags.follow_renames)
		rev->always_show_header = 0;

	if (source || w.source) {
		init_revision_sources(&revision_sources);
		rev->sources = &revision_sources;
	}

	if (mailmap) {
		rev->mailmap = xcalloc(1, sizeof(struct string_list));
		read_mailmap(rev->mailmap, NULL);
	}

	if (rev->pretty_given && rev->commit_format == CMIT_FMT_RAW) {
		/*
		 * "log --pretty=raw" is special; ignore UI oriented
		 * configuration variables such as decoration.
		 */
		if (!decoration_given)
			decoration_style = 0;
		if (!rev->abbrev_commit_given)
			rev->abbrev_commit = 0;
	}

	if (decoration_style) {
		rev->show_decorations = 1;
		load_ref_decorations(&decoration_filter, decoration_style);
	}

	if (rev->line_level_traverse)
		line_log_init(rev, line_cb.prefix, &line_cb.args);

	setup_pager();
}

static void cmd_log_init(int argc, const char **argv, const char *prefix,
			 struct rev_info *rev, struct setup_revision_opt *opt)
{
	cmd_log_init_defaults(rev);
	cmd_log_init_finish(argc, argv, prefix, rev, opt);
}

/*
 * This gives a rough estimate for how many commits we
 * will print out in the list.
 */
static int estimate_commit_count(struct commit_list *list)
{
	int n = 0;

	while (list) {
		struct commit *commit = list->item;
		unsigned int flags = commit->object.flags;
		list = list->next;
		if (!(flags & (TREESAME | UNINTERESTING)))
			n++;
	}
	return n;
}

static void show_early_header(struct rev_info *rev, const char *stage, int nr)
{
	if (rev->shown_one) {
		rev->shown_one = 0;
		if (rev->commit_format != CMIT_FMT_ONELINE)
			putchar(rev->diffopt.line_termination);
	}
	fprintf(rev->diffopt.file, _("Final output: %d %s\n"), nr, stage);
}

static struct itimerval early_output_timer;

static void log_show_early(struct rev_info *revs, struct commit_list *list)
{
	int i = revs->early_output, close_file = revs->diffopt.close_file;
	int show_header = 1;

	revs->diffopt.close_file = 0;
	sort_in_topological_order(&list, revs->sort_order);
	while (list && i) {
		struct commit *commit = list->item;
		switch (simplify_commit(revs, commit)) {
		case commit_show:
			if (show_header) {
				int n = estimate_commit_count(list);
				show_early_header(revs, "incomplete", n);
				show_header = 0;
			}
			log_tree_commit(revs, commit);
			i--;
			break;
		case commit_ignore:
			break;
		case commit_error:
			if (close_file)
				fclose(revs->diffopt.file);
			return;
		}
		list = list->next;
	}

	/* Did we already get enough commits for the early output? */
	if (!i) {
		if (close_file)
			fclose(revs->diffopt.file);
		return;
	}

	/*
	 * ..if no, then repeat it twice a second until we
	 * do.
	 *
	 * NOTE! We don't use "it_interval", because if the
	 * reader isn't listening, we want our output to be
	 * throttled by the writing, and not have the timer
	 * trigger every second even if we're blocked on a
	 * reader!
	 */
	early_output_timer.it_value.tv_sec = 0;
	early_output_timer.it_value.tv_usec = 500000;
	setitimer(ITIMER_REAL, &early_output_timer, NULL);
}

static void early_output(int signal)
{
	show_early_output = log_show_early;
}

static void setup_early_output(void)
{
	struct sigaction sa;

	/*
	 * Set up the signal handler, minimally intrusively:
	 * we only set a single volatile integer word (not
	 * using sigatomic_t - trying to avoid unnecessary
	 * system dependencies and headers), and using
	 * SA_RESTART.
	 */
	memset(&sa, 0, sizeof(sa));
	sa.sa_handler = early_output;
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = SA_RESTART;
	sigaction(SIGALRM, &sa, NULL);

	/*
	 * If we can get the whole output in less than a
	 * tenth of a second, don't even bother doing the
	 * early-output thing..
	 *
	 * This is a one-time-only trigger.
	 */
	early_output_timer.it_value.tv_sec = 0;
	early_output_timer.it_value.tv_usec = 100000;
	setitimer(ITIMER_REAL, &early_output_timer, NULL);
}

static void finish_early_output(struct rev_info *rev)
{
	int n = estimate_commit_count(rev->commits);
	signal(SIGALRM, SIG_IGN);
	show_early_header(rev, "done", n);
}

static int cmd_log_walk(struct rev_info *rev)
{
	struct commit *commit;
	int saved_nrl = 0;
	int saved_dcctc = 0, close_file = rev->diffopt.close_file;

	if (rev->early_output)
		setup_early_output();

	if (prepare_revision_walk(rev))
		die(_("revision walk setup failed"));

	if (rev->early_output)
		finish_early_output(rev);

	/*
	 * For --check and --exit-code, the exit code is based on CHECK_FAILED
	 * and HAS_CHANGES being accumulated in rev->diffopt, so be careful to
	 * retain that state information if replacing rev->diffopt in this loop
	 */
	rev->diffopt.close_file = 0;
	while ((commit = get_revision(rev)) != NULL) {
		if (!log_tree_commit(rev, commit) && rev->max_count >= 0)
			/*
			 * We decremented max_count in get_revision,
			 * but we didn't actually show the commit.
			 */
			rev->max_count++;
		if (!rev->reflog_info) {
			/*
			 * We may show a given commit multiple times when
			 * walking the reflogs.
			 */
			free_commit_buffer(the_repository->parsed_objects,
					   commit);
			free_commit_list(commit->parents);
			commit->parents = NULL;
		}
		if (saved_nrl < rev->diffopt.needed_rename_limit)
			saved_nrl = rev->diffopt.needed_rename_limit;
		if (rev->diffopt.degraded_cc_to_c)
			saved_dcctc = 1;
	}
	rev->diffopt.degraded_cc_to_c = saved_dcctc;
	rev->diffopt.needed_rename_limit = saved_nrl;
	if (close_file)
		fclose(rev->diffopt.file);

	if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF &&
	    rev->diffopt.flags.check_failed) {
		return 02;
	}
	return diff_result_code(&rev->diffopt, 0);
}

static int git_log_config(const char *var, const char *value, void *cb)
{
	const char *slot_name;

	if (!strcmp(var, "format.pretty"))
		return git_config_string(&fmt_pretty, var, value);
	if (!strcmp(var, "format.subjectprefix"))
		return git_config_string(&fmt_patch_subject_prefix, var, value);
	if (!strcmp(var, "log.abbrevcommit")) {
		default_abbrev_commit = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp(var, "log.date"))
		return git_config_string(&default_date_mode, var, value);
	if (!strcmp(var, "log.decorate")) {
		decoration_style = parse_decoration_style(value);
		if (decoration_style < 0)
			decoration_style = 0; /* maybe warn? */
		return 0;
	}
	if (!strcmp(var, "log.showroot")) {
		default_show_root = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp(var, "log.follow")) {
		default_follow = git_config_bool(var, value);
		return 0;
	}
	if (skip_prefix(var, "color.decorate.", &slot_name))
		return parse_decorate_color_config(var, slot_name, value);
	if (!strcmp(var, "log.mailmap")) {
		use_mailmap_config = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp(var, "log.showsignature")) {
		default_show_signature = git_config_bool(var, value);
		return 0;
	}

	if (grep_config(var, value, cb) < 0)
		return -1;
	if (git_gpg_config(var, value, cb) < 0)
		return -1;
	return git_diff_ui_config(var, value, cb);
}

int cmd_whatchanged(int argc, const char **argv, const char *prefix)
{
	struct rev_info rev;
	struct setup_revision_opt opt;

	init_log_defaults();
	git_config(git_log_config, NULL);

	repo_init_revisions(the_repository, &rev, prefix);
	rev.diff = 1;
	rev.simplify_history = 0;
	memset(&opt, 0, sizeof(opt));
	opt.def = "HEAD";
	opt.revarg_opt = REVARG_COMMITTISH;
	cmd_log_init(argc, argv, prefix, &rev, &opt);
	if (!rev.diffopt.output_format)
		rev.diffopt.output_format = DIFF_FORMAT_RAW;
	return cmd_log_walk(&rev);
}

static void show_tagger(const char *buf, struct rev_info *rev)
{
	struct strbuf out = STRBUF_INIT;
	struct pretty_print_context pp = {0};

	pp.fmt = rev->commit_format;
	pp.date_mode = rev->date_mode;
	pp_user_info(&pp, "Tagger", &out, buf, get_log_output_encoding());
	fprintf(rev->diffopt.file, "%s", out.buf);
	strbuf_release(&out);
}

static int show_blob_object(const struct object_id *oid, struct rev_info *rev, const char *obj_name)
{
	struct object_id oidc;
	struct object_context obj_context;
	char *buf;
	unsigned long size;

	fflush(rev->diffopt.file);
	if (!rev->diffopt.flags.textconv_set_via_cmdline ||
	    !rev->diffopt.flags.allow_textconv)
		return stream_blob_to_fd(1, oid, NULL, 0);

	if (get_oid_with_context(the_repository, obj_name,
				 GET_OID_RECORD_PATH,
				 &oidc, &obj_context))
		die(_("not a valid object name %s"), obj_name);
	if (!obj_context.path ||
	    !textconv_object(the_repository, obj_context.path,
			     obj_context.mode, &oidc, 1, &buf, &size)) {
		free(obj_context.path);
		return stream_blob_to_fd(1, oid, NULL, 0);
	}

	if (!buf)
		die(_("git show %s: bad file"), obj_name);

	write_or_die(1, buf, size);
	free(obj_context.path);
	return 0;
}

static int show_tag_object(const struct object_id *oid, struct rev_info *rev)
{
	unsigned long size;
	enum object_type type;
	char *buf = read_object_file(oid, &type, &size);
	int offset = 0;

	if (!buf)
		return error(_("could not read object %s"), oid_to_hex(oid));

	assert(type == OBJ_TAG);
	while (offset < size && buf[offset] != '\n') {
		int new_offset = offset + 1;
		const char *ident;
		while (new_offset < size && buf[new_offset++] != '\n')
			; /* do nothing */
		if (skip_prefix(buf + offset, "tagger ", &ident))
			show_tagger(ident, rev);
		offset = new_offset;
	}

	if (offset < size)
		fwrite(buf + offset, size - offset, 1, rev->diffopt.file);
	free(buf);
	return 0;
}

static int show_tree_object(const struct object_id *oid,
		struct strbuf *base,
		const char *pathname, unsigned mode, int stage, void *context)
{
	FILE *file = context;
	fprintf(file, "%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
	return 0;
}

static void show_setup_revisions_tweak(struct rev_info *rev,
				       struct setup_revision_opt *opt)
{
	if (rev->ignore_merges) {
		/* There was no "-m" on the command line */
		rev->ignore_merges = 0;
		if (!rev->first_parent_only && !rev->combine_merges) {
			/* No "--first-parent", "-c", or "--cc" */
			rev->combine_merges = 1;
			rev->dense_combined_merges = 1;
		}
	}
	if (!rev->diffopt.output_format)
		rev->diffopt.output_format = DIFF_FORMAT_PATCH;
}

int cmd_show(int argc, const char **argv, const char *prefix)
{
	struct rev_info rev;
	struct object_array_entry *objects;
	struct setup_revision_opt opt;
	struct pathspec match_all;
	int i, count, ret = 0;

	init_log_defaults();
	git_config(git_log_config, NULL);

	memset(&match_all, 0, sizeof(match_all));
	repo_init_revisions(the_repository, &rev, prefix);
	rev.diff = 1;
	rev.always_show_header = 1;
	rev.no_walk = REVISION_WALK_NO_WALK_SORTED;
	rev.diffopt.stat_width = -1; 	/* Scale to real terminal size */

	memset(&opt, 0, sizeof(opt));
	opt.def = "HEAD";
	opt.tweak = show_setup_revisions_tweak;
	cmd_log_init(argc, argv, prefix, &rev, &opt);

	if (!rev.no_walk)
		return cmd_log_walk(&rev);

	count = rev.pending.nr;
	objects = rev.pending.objects;
	for (i = 0; i < count && !ret; i++) {
		struct object *o = objects[i].item;
		const char *name = objects[i].name;
		switch (o->type) {
		case OBJ_BLOB:
			ret = show_blob_object(&o->oid, &rev, name);
			break;
		case OBJ_TAG: {
			struct tag *t = (struct tag *)o;

			if (rev.shown_one)
				putchar('\n');
			fprintf(rev.diffopt.file, "%stag %s%s\n",
					diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
					t->tag,
					diff_get_color_opt(&rev.diffopt, DIFF_RESET));
			ret = show_tag_object(&o->oid, &rev);
			rev.shown_one = 1;
			if (ret)
				break;
			o = parse_object(the_repository, &t->tagged->oid);
			if (!o)
				ret = error(_("could not read object %s"),
					    oid_to_hex(&t->tagged->oid));
			objects[i].item = o;
			i--;
			break;
		}
		case OBJ_TREE:
			if (rev.shown_one)
				putchar('\n');
			fprintf(rev.diffopt.file, "%stree %s%s\n\n",
					diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
					name,
					diff_get_color_opt(&rev.diffopt, DIFF_RESET));
			read_tree_recursive(the_repository, (struct tree *)o, "",
					    0, 0, &match_all, show_tree_object,
					    rev.diffopt.file);
			rev.shown_one = 1;
			break;
		case OBJ_COMMIT:
			rev.pending.nr = rev.pending.alloc = 0;
			rev.pending.objects = NULL;
			add_object_array(o, name, &rev.pending);
			ret = cmd_log_walk(&rev);
			break;
		default:
			ret = error(_("unknown type: %d"), o->type);
		}
	}
	free(objects);
	return ret;
}

/*
 * This is equivalent to "git log -g --abbrev-commit --pretty=oneline"
 */
int cmd_log_reflog(int argc, const char **argv, const char *prefix)
{
	struct rev_info rev;
	struct setup_revision_opt opt;

	init_log_defaults();
	git_config(git_log_config, NULL);

	repo_init_revisions(the_repository, &rev, prefix);
	init_reflog_walk(&rev.reflog_info);
	rev.verbose_header = 1;
	memset(&opt, 0, sizeof(opt));
	opt.def = "HEAD";
	cmd_log_init_defaults(&rev);
	rev.abbrev_commit = 1;
	rev.commit_format = CMIT_FMT_ONELINE;
	rev.use_terminator = 1;
	rev.always_show_header = 1;
	cmd_log_init_finish(argc, argv, prefix, &rev, &opt);

	return cmd_log_walk(&rev);
}

static void log_setup_revisions_tweak(struct rev_info *rev,
				      struct setup_revision_opt *opt)
{
	if (rev->diffopt.flags.default_follow_renames &&
	    rev->prune_data.nr == 1)
		rev->diffopt.flags.follow_renames = 1;

	/* Turn --cc/-c into -p --cc/-c when -p was not given */
	if (!rev->diffopt.output_format && rev->combine_merges)
		rev->diffopt.output_format = DIFF_FORMAT_PATCH;

	/* Turn -m on when --cc/-c was given */
	if (rev->combine_merges)
		rev->ignore_merges = 0;
}

int cmd_log(int argc, const char **argv, const char *prefix)
{
	struct rev_info rev;
	struct setup_revision_opt opt;

	init_log_defaults();
	git_config(git_log_config, NULL);

	repo_init_revisions(the_repository, &rev, prefix);
	rev.always_show_header = 1;
	memset(&opt, 0, sizeof(opt));
	opt.def = "HEAD";
	opt.revarg_opt = REVARG_COMMITTISH;
	opt.tweak = log_setup_revisions_tweak;
	cmd_log_init(argc, argv, prefix, &rev, &opt);
	return cmd_log_walk(&rev);
}

/* format-patch */

static const char *fmt_patch_suffix = ".patch";
static int numbered = 0;
static int auto_number = 1;

static char *default_attach = NULL;

static struct string_list extra_hdr = STRING_LIST_INIT_NODUP;
static struct string_list extra_to = STRING_LIST_INIT_NODUP;
static struct string_list extra_cc = STRING_LIST_INIT_NODUP;

static void add_header(const char *value)
{
	struct string_list_item *item;
	int len = strlen(value);
	while (len && value[len - 1] == '\n')
		len--;

	if (!strncasecmp(value, "to: ", 4)) {
		item = string_list_append(&extra_to, value + 4);
		len -= 4;
	} else if (!strncasecmp(value, "cc: ", 4)) {
		item = string_list_append(&extra_cc, value + 4);
		len -= 4;
	} else {
		item = string_list_append(&extra_hdr, value);
	}

	item->string[len] = '\0';
}

#define THREAD_SHALLOW 1
#define THREAD_DEEP 2
static int thread;
static int do_signoff;
static int base_auto;
static char *from;
static const char *signature = git_version_string;
static const char *signature_file;
static int config_cover_letter;
static const char *config_output_directory;

enum {
	COVER_UNSET,
	COVER_OFF,
	COVER_ON,
	COVER_AUTO
};

static int git_format_config(const char *var, const char *value, void *cb)
{
	struct rev_info *rev = cb;

	if (!strcmp(var, "format.headers")) {
		if (!value)
			die(_("format.headers without value"));
		add_header(value);
		return 0;
	}
	if (!strcmp(var, "format.suffix"))
		return git_config_string(&fmt_patch_suffix, var, value);
	if (!strcmp(var, "format.to")) {
		if (!value)
			return config_error_nonbool(var);
		string_list_append(&extra_to, value);
		return 0;
	}
	if (!strcmp(var, "format.cc")) {
		if (!value)
			return config_error_nonbool(var);
		string_list_append(&extra_cc, value);
		return 0;
	}
	if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff") ||
	    !strcmp(var, "color.ui") || !strcmp(var, "diff.submodule")) {
		return 0;
	}
	if (!strcmp(var, "format.numbered")) {
		if (value && !strcasecmp(value, "auto")) {
			auto_number = 1;
			return 0;
		}
		numbered = git_config_bool(var, value);
		auto_number = auto_number && numbered;
		return 0;
	}
	if (!strcmp(var, "format.attach")) {
		if (value && *value)
			default_attach = xstrdup(value);
		else
			default_attach = xstrdup(git_version_string);
		return 0;
	}
	if (!strcmp(var, "format.thread")) {
		if (value && !strcasecmp(value, "deep")) {
			thread = THREAD_DEEP;
			return 0;
		}
		if (value && !strcasecmp(value, "shallow")) {
			thread = THREAD_SHALLOW;
			return 0;
		}
		thread = git_config_bool(var, value) && THREAD_SHALLOW;
		return 0;
	}
	if (!strcmp(var, "format.signoff")) {
		do_signoff = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp(var, "format.signature"))
		return git_config_string(&signature, var, value);
	if (!strcmp(var, "format.signaturefile"))
		return git_config_pathname(&signature_file, var, value);
	if (!strcmp(var, "format.coverletter")) {
		if (value && !strcasecmp(value, "auto")) {
			config_cover_letter = COVER_AUTO;
			return 0;
		}
		config_cover_letter = git_config_bool(var, value) ? COVER_ON : COVER_OFF;
		return 0;
	}
	if (!strcmp(var, "format.outputdirectory"))
		return git_config_string(&config_output_directory, var, value);
	if (!strcmp(var, "format.useautobase")) {
		base_auto = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp(var, "format.from")) {
		int b = git_parse_maybe_bool(value);
		free(from);
		if (b < 0)
			from = xstrdup(value);
		else if (b)
			from = xstrdup(git_committer_info(IDENT_NO_DATE));
		else
			from = NULL;
		return 0;
	}
	if (!strcmp(var, "format.notes")) {
		struct strbuf buf = STRBUF_INIT;
		int b = git_parse_maybe_bool(value);
		if (!b)
			return 0;
		rev->show_notes = 1;
		if (b < 0) {
			strbuf_addstr(&buf, value);
			expand_notes_ref(&buf);
			string_list_append(&rev->notes_opt.extra_notes_refs,
					strbuf_detach(&buf, NULL));
		} else {
			rev->notes_opt.use_default_notes = 1;
		}
		return 0;
	}

	return git_log_config(var, value, cb);
}

static const char *output_directory = NULL;
static int outdir_offset;

static int open_next_file(struct commit *commit, const char *subject,
			 struct rev_info *rev, int quiet)
{
	struct strbuf filename = STRBUF_INIT;
	int suffix_len = strlen(rev->patch_suffix) + 1;

	if (output_directory) {
		strbuf_addstr(&filename, output_directory);
		if (filename.len >=
		    PATH_MAX - FORMAT_PATCH_NAME_MAX - suffix_len) {
			strbuf_release(&filename);
			return error(_("name of output directory is too long"));
		}
		strbuf_complete(&filename, '/');
	}

	if (rev->numbered_files)
		strbuf_addf(&filename, "%d", rev->nr);
	else if (commit)
		fmt_output_commit(&filename, commit, rev);
	else
		fmt_output_subject(&filename, subject, rev);

	if (!quiet)
		printf("%s\n", filename.buf + outdir_offset);

	if ((rev->diffopt.file = fopen(filename.buf, "w")) == NULL) {
		error_errno(_("cannot open patch file %s"), filename.buf);
		strbuf_release(&filename);
		return -1;
	}

	strbuf_release(&filename);
	return 0;
}

static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids)
{
	struct rev_info check_rev;
	struct commit *commit, *c1, *c2;
	struct object *o1, *o2;
	unsigned flags1, flags2;

	if (rev->pending.nr != 2)
		die(_("need exactly one range"));

	o1 = rev->pending.objects[0].item;
	o2 = rev->pending.objects[1].item;
	flags1 = o1->flags;
	flags2 = o2->flags;
	c1 = lookup_commit_reference(the_repository, &o1->oid);
	c2 = lookup_commit_reference(the_repository, &o2->oid);

	if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
		die(_("not a range"));

	init_patch_ids(the_repository, ids);

	/* given a range a..b get all patch ids for b..a */
	repo_init_revisions(the_repository, &check_rev, rev->prefix);
	check_rev.max_parents = 1;
	o1->flags ^= UNINTERESTING;
	o2->flags ^= UNINTERESTING;
	add_pending_object(&check_rev, o1, "o1");
	add_pending_object(&check_rev, o2, "o2");
	if (prepare_revision_walk(&check_rev))
		die(_("revision walk setup failed"));

	while ((commit = get_revision(&check_rev)) != NULL) {
		add_commit_patch_id(commit, ids);
	}

	/* reset for next revision walk */
	clear_commit_marks(c1, SEEN | UNINTERESTING | SHOWN | ADDED);
	clear_commit_marks(c2, SEEN | UNINTERESTING | SHOWN | ADDED);
	o1->flags = flags1;
	o2->flags = flags2;
}

static void gen_message_id(struct rev_info *info, char *base)
{
	struct strbuf buf = STRBUF_INIT;
	strbuf_addf(&buf, "%s.%"PRItime".git.%s", base,
		    (timestamp_t) time(NULL),
		    git_committer_info(IDENT_NO_NAME|IDENT_NO_DATE|IDENT_STRICT));
	info->message_id = strbuf_detach(&buf, NULL);
}

static void print_signature(FILE *file)
{
	if (!signature || !*signature)
		return;

	fprintf(file, "-- \n%s", signature);
	if (signature[strlen(signature)-1] != '\n')
		putc('\n', file);
	putc('\n', file);
}

static void add_branch_description(struct strbuf *buf, const char *branch_name)
{
	struct strbuf desc = STRBUF_INIT;
	if (!branch_name || !*branch_name)
		return;
	read_branch_desc(&desc, branch_name);
	if (desc.len) {
		strbuf_addch(buf, '\n');
		strbuf_addbuf(buf, &desc);
		strbuf_addch(buf, '\n');
	}
	strbuf_release(&desc);
}

static char *find_branch_name(struct rev_info *rev)
{
	int i, positive = -1;
	struct object_id branch_oid;
	const struct object_id *tip_oid;
	const char *ref, *v;
	char *full_ref, *branch = NULL;

	for (i = 0; i < rev->cmdline.nr; i++) {
		if (rev->cmdline.rev[i].flags & UNINTERESTING)
			continue;
		if (positive < 0)
			positive = i;
		else
			return NULL;
	}
	if (positive < 0)
		return NULL;
	ref = rev->cmdline.rev[positive].name;
	tip_oid = &rev->cmdline.rev[positive].item->oid;
	if (dwim_ref(ref, strlen(ref), &branch_oid, &full_ref) &&
	    skip_prefix(full_ref, "refs/heads/", &v) &&
	    oideq(tip_oid, &branch_oid))
		branch = xstrdup(v);
	free(full_ref);
	return branch;
}

static void show_diffstat(struct rev_info *rev,
			  struct commit *origin, struct commit *head)
{
	struct diff_options opts;

	memcpy(&opts, &rev->diffopt, sizeof(opts));
	opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
	diff_setup_done(&opts);

	diff_tree_oid(get_commit_tree_oid(origin),
		      get_commit_tree_oid(head),
		      "", &opts);
	diffcore_std(&opts);
	diff_flush(&opts);

	fprintf(rev->diffopt.file, "\n");
}

static void make_cover_letter(struct rev_info *rev, int use_stdout,
			      struct commit *origin,
			      int nr, struct commit **list,
			      const char *branch_name,
			      int quiet)
{
	const char *committer;
	const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
	const char *msg;
	struct shortlog log;
	struct strbuf sb = STRBUF_INIT;
	int i;
	const char *encoding = "UTF-8";
	int need_8bit_cte = 0;
	struct pretty_print_context pp = {0};
	struct commit *head = list[0];

	if (!cmit_fmt_is_mail(rev->commit_format))
		die(_("cover letter needs email format"));

	committer = git_committer_info(0);

	if (!use_stdout &&
	    open_next_file(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
		die(_("failed to create cover-letter file"));

	log_write_email_headers(rev, head, &pp.after_subject, &need_8bit_cte, 0);

	for (i = 0; !need_8bit_cte && i < nr; i++) {
		const char *buf = get_commit_buffer(list[i], NULL);
		if (has_non_ascii(buf))
			need_8bit_cte = 1;
		unuse_commit_buffer(list[i], buf);
	}

	if (!branch_name)
		branch_name = find_branch_name(rev);

	msg = body;
	pp.fmt = CMIT_FMT_EMAIL;
	pp.date_mode.type = DATE_RFC2822;
	pp.rev = rev;
	pp.print_email_subject = 1;
	pp_user_info(&pp, NULL, &sb, committer, encoding);
	pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
	pp_remainder(&pp, &msg, &sb, 0);
	add_branch_description(&sb, branch_name);
	fprintf(rev->diffopt.file, "%s\n", sb.buf);

	strbuf_release(&sb);

	shortlog_init(&log);
	log.wrap_lines = 1;
	log.wrap = MAIL_DEFAULT_WRAP;
	log.in1 = 2;
	log.in2 = 4;
	log.file = rev->diffopt.file;
	for (i = 0; i < nr; i++)
		shortlog_add_commit(&log, list[i]);

	shortlog_output(&log);

	/* We can only do diffstat with a unique reference point */
	if (origin)
		show_diffstat(rev, origin, head);

	if (rev->idiff_oid1) {
		fprintf_ln(rev->diffopt.file, "%s", rev->idiff_title);
		show_interdiff(rev, 0);
	}

	if (rev->rdiff1) {
		/*
		 * Pass minimum required diff-options to range-diff; others
		 * can be added later if deemed desirable.
		 */
		struct diff_options opts;
		diff_setup(&opts);
		opts.file = rev->diffopt.file;
		opts.use_color = rev->diffopt.use_color;
		diff_setup_done(&opts);
		fprintf_ln(rev->diffopt.file, "%s", rev->rdiff_title);
		show_range_diff(rev->rdiff1, rev->rdiff2,
				rev->creation_factor, 1, &opts);
	}
}

static const char *clean_message_id(const char *msg_id)
{
	char ch;
	const char *a, *z, *m;

	m = msg_id;
	while ((ch = *m) && (isspace(ch) || (ch == '<')))
		m++;
	a = m;
	z = NULL;
	while ((ch = *m)) {
		if (!isspace(ch) && (ch != '>'))
			z = m;
		m++;
	}
	if (!z)
		die(_("insane in-reply-to: %s"), msg_id);
	if (++z == m)
		return a;
	return xmemdupz(a, z - a);
}

static const char *set_outdir(const char *prefix, const char *output_directory)
{
	if (output_directory && is_absolute_path(output_directory))
		return output_directory;

	if (!prefix || !*prefix) {
		if (output_directory)
			return output_directory;
		/* The user did not explicitly ask for "./" */
		outdir_offset = 2;
		return "./";
	}

	outdir_offset = strlen(prefix);
	if (!output_directory)
		return prefix;

	return prefix_filename(prefix, output_directory);
}

static const char * const builtin_format_patch_usage[] = {
	N_("git format-patch [<options>] [<since> | <revision-range>]"),
	NULL
};

static int keep_subject = 0;

static int keep_callback(const struct option *opt, const char *arg, int unset)
{
	BUG_ON_OPT_NEG(unset);
	BUG_ON_OPT_ARG(arg);
	((struct rev_info *)opt->value)->total = -1;
	keep_subject = 1;
	return 0;
}

static int subject_prefix = 0;

static int subject_prefix_callback(const struct option *opt, const char *arg,
			    int unset)
{
	BUG_ON_OPT_NEG(unset);
	subject_prefix = 1;
	((struct rev_info *)opt->value)->subject_prefix = arg;
	return 0;
}

static int rfc_callback(const struct option *opt, const char *arg, int unset)
{
	BUG_ON_OPT_NEG(unset);
	BUG_ON_OPT_ARG(arg);
	return subject_prefix_callback(opt, "RFC PATCH", unset);
}

static int numbered_cmdline_opt = 0;

static int numbered_callback(const struct option *opt, const char *arg,
			     int unset)
{
	BUG_ON_OPT_ARG(arg);
	*(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
	if (unset)
		auto_number =  0;
	return 0;
}

static int no_numbered_callback(const struct option *opt, const char *arg,
				int unset)
{
	BUG_ON_OPT_NEG(unset);
	return numbered_callback(opt, arg, 1);
}

static int output_directory_callback(const struct option *opt, const char *arg,
			      int unset)
{
	const char **dir = (const char **)opt->value;
	BUG_ON_OPT_NEG(unset);
	if (*dir)
		die(_("two output directories?"));
	*dir = arg;
	return 0;
}

static int thread_callback(const struct option *opt, const char *arg, int unset)
{
	int *thread = (int *)opt->value;
	if (unset)
		*thread = 0;
	else if (!arg || !strcmp(arg, "shallow"))
		*thread = THREAD_SHALLOW;
	else if (!strcmp(arg, "deep"))
		*thread = THREAD_DEEP;
	/*
	 * Please update _git_formatpatch() in git-completion.bash
	 * when you add new options.
	 */
	else
		return 1;
	return 0;
}

static int attach_callback(const struct option *opt, const char *arg, int unset)
{
	struct rev_info *rev = (struct rev_info *)opt->value;
	if (unset)
		rev->mime_boundary = NULL;
	else if (arg)
		rev->mime_boundary = arg;
	else
		rev->mime_boundary = git_version_string;
	rev->no_inline = unset ? 0 : 1;
	return 0;
}

static int inline_callback(const struct option *opt, const char *arg, int unset)
{
	struct rev_info *rev = (struct rev_info *)opt->value;
	if (unset)
		rev->mime_boundary = NULL;
	else if (arg)
		rev->mime_boundary = arg;
	else
		rev->mime_boundary = git_version_string;
	rev->no_inline = 0;
	return 0;
}

static int header_callback(const struct option *opt, const char *arg, int unset)
{
	if (unset) {
		string_list_clear(&extra_hdr, 0);
		string_list_clear(&extra_to, 0);
		string_list_clear(&extra_cc, 0);
	} else {
	    add_header(arg);
	}
	return 0;
}

static int to_callback(const struct option *opt, const char *arg, int unset)
{
	if (unset)
		string_list_clear(&extra_to, 0);
	else
		string_list_append(&extra_to, arg);
	return 0;
}

static int cc_callback(const struct option *opt, const char *arg, int unset)
{
	if (unset)
		string_list_clear(&extra_cc, 0);
	else
		string_list_append(&extra_cc, arg);
	return 0;
}

static int from_callback(const struct option *opt, const char *arg, int unset)
{
	char **from = opt->value;

	free(*from);

	if (unset)
		*from = NULL;
	else if (arg)
		*from = xstrdup(arg);
	else
		*from = xstrdup(git_committer_info(IDENT_NO_DATE));
	return 0;
}

struct base_tree_info {
	struct object_id base_commit;
	int nr_patch_id, alloc_patch_id;
	struct object_id *patch_id;
};

static struct commit *get_base_commit(const char *base_commit,
				      struct commit **list,
				      int total)
{
	struct commit *base = NULL;
	struct commit **rev;
	int i = 0, rev_nr = 0;

	if (base_commit && strcmp(base_commit, "auto")) {
		base = lookup_commit_reference_by_name(base_commit);
		if (!base)
			die(_("unknown commit %s"), base_commit);
	} else if ((base_commit && !strcmp(base_commit, "auto")) || base_auto) {
		struct branch *curr_branch = branch_get(NULL);
		const char *upstream = branch_get_upstream(curr_branch, NULL);
		if (upstream) {
			struct commit_list *base_list;
			struct commit *commit;
			struct object_id oid;

			if (get_oid(upstream, &oid))
				die(_("failed to resolve '%s' as a valid ref"), upstream);
			commit = lookup_commit_or_die(&oid, "upstream base");
			base_list = get_merge_bases_many(commit, total, list);
			/* There should be one and only one merge base. */
			if (!base_list || base_list->next)
				die(_("could not find exact merge base"));
			base = base_list->item;
			free_commit_list(base_list);
		} else {
			die(_("failed to get upstream, if you want to record base commit automatically,\n"
			      "please use git branch --set-upstream-to to track a remote branch.\n"
			      "Or you could specify base commit by --base=<base-commit-id> manually"));
		}
	}

	ALLOC_ARRAY(rev, total);
	for (i = 0; i < total; i++)
		rev[i] = list[i];

	rev_nr = total;
	/*
	 * Get merge base through pair-wise computations
	 * and store it in rev[0].
	 */
	while (rev_nr > 1) {
		for (i = 0; i < rev_nr / 2; i++) {
			struct commit_list *merge_base;
			merge_base = get_merge_bases(rev[2 * i], rev[2 * i + 1]);
			if (!merge_base || merge_base->next)
				die(_("failed to find exact merge base"));

			rev[i] = merge_base->item;
		}

		if (rev_nr % 2)
			rev[i] = rev[2 * i];
		rev_nr = DIV_ROUND_UP(rev_nr, 2);
	}

	if (!in_merge_bases(base, rev[0]))
		die(_("base commit should be the ancestor of revision list"));

	for (i = 0; i < total; i++) {
		if (base == list[i])
			die(_("base commit shouldn't be in revision list"));
	}

	free(rev);
	return base;
}

define_commit_slab(commit_base, int);

static void prepare_bases(struct base_tree_info *bases,
			  struct commit *base,
			  struct commit **list,
			  int total)
{
	struct commit *commit;
	struct rev_info revs;
	struct diff_options diffopt;
	struct commit_base commit_base;
	int i;

	if (!base)
		return;

	init_commit_base(&commit_base);
	repo_diff_setup(the_repository, &diffopt);
	diffopt.flags.recursive = 1;
	diff_setup_done(&diffopt);

	oidcpy(&bases->base_commit, &base->object.oid);

	repo_init_revisions(the_repository, &revs, NULL);
	revs.max_parents = 1;
	revs.topo_order = 1;
	for (i = 0; i < total; i++) {
		list[i]->object.flags &= ~UNINTERESTING;
		add_pending_object(&revs, &list[i]->object, "rev_list");
		*commit_base_at(&commit_base, list[i]) = 1;
	}
	base->object.flags |= UNINTERESTING;
	add_pending_object(&revs, &base->object, "base");

	if (prepare_revision_walk(&revs))
		die(_("revision walk setup failed"));
	/*
	 * Traverse the commits list, get prerequisite patch ids
	 * and stuff them in bases structure.
	 */
	while ((commit = get_revision(&revs)) != NULL) {
		struct object_id oid;
		struct object_id *patch_id;
		if (*commit_base_at(&commit_base, commit))
			continue;
		if (commit_patch_id(commit, &diffopt, &oid, 0, 1))
			die(_("cannot get patch id"));
		ALLOC_GROW(bases->patch_id, bases->nr_patch_id + 1, bases->alloc_patch_id);
		patch_id = bases->patch_id + bases->nr_patch_id;
		oidcpy(patch_id, &oid);
		bases->nr_patch_id++;
	}
	clear_commit_base(&commit_base);
}

static void print_bases(struct base_tree_info *bases, FILE *file)
{
	int i;

	/* Only do this once, either for the cover or for the first one */
	if (is_null_oid(&bases->base_commit))
		return;

	/* Show the base commit */
	fprintf(file, "\nbase-commit: %s\n", oid_to_hex(&bases->base_commit));

	/* Show the prerequisite patches */
	for (i = bases->nr_patch_id - 1; i >= 0; i--)
		fprintf(file, "prerequisite-patch-id: %s\n", oid_to_hex(&bases->patch_id[i]));

	free(bases->patch_id);
	bases->nr_patch_id = 0;
	bases->alloc_patch_id = 0;
	oidclr(&bases->base_commit);
}

static const char *diff_title(struct strbuf *sb, int reroll_count,
		       const char *generic, const char *rerolled)
{
	if (reroll_count <= 0)
		strbuf_addstr(sb, generic);
	else /* RFC may be v0, so allow -v1 to diff against v0 */
		strbuf_addf(sb, rerolled, reroll_count - 1);
	return sb->buf;
}

static void infer_range_diff_ranges(struct strbuf *r1,
				    struct strbuf *r2,
				    const char *prev,
				    struct commit *origin,
				    struct commit *head)
{
	const char *head_oid = oid_to_hex(&head->object.oid);

	if (!strstr(prev, "..")) {
		strbuf_addf(r1, "%s..%s", head_oid, prev);
		strbuf_addf(r2, "%s..%s", prev, head_oid);
	} else if (!origin) {
		die(_("failed to infer range-diff ranges"));
	} else {
		strbuf_addstr(r1, prev);
		strbuf_addf(r2, "%s..%s",
			    oid_to_hex(&origin->object.oid), head_oid);
	}
}

int cmd_format_patch(int argc, const char **argv, const char *prefix)
{
	struct commit *commit;
	struct commit **list = NULL;
	struct rev_info rev;
	struct setup_revision_opt s_r_opt;
	int nr = 0, total, i;
	int use_stdout = 0;
	int start_number = -1;
	int just_numbers = 0;
	int ignore_if_in_upstream = 0;
	int cover_letter = -1;
	int boundary_count = 0;
	int no_binary_diff = 0;
	int zero_commit = 0;
	struct commit *origin = NULL;
	const char *in_reply_to = NULL;
	struct patch_ids ids;
	struct strbuf buf = STRBUF_INIT;
	int use_patch_format = 0;
	int quiet = 0;
	int reroll_count = -1;
	char *branch_name = NULL;
	char *base_commit = NULL;
	struct base_tree_info bases;
	int show_progress = 0;
	struct progress *progress = NULL;
	struct oid_array idiff_prev = OID_ARRAY_INIT;
	struct strbuf idiff_title = STRBUF_INIT;
	const char *rdiff_prev = NULL;
	struct strbuf rdiff1 = STRBUF_INIT;
	struct strbuf rdiff2 = STRBUF_INIT;
	struct strbuf rdiff_title = STRBUF_INIT;
	int creation_factor = -1;

	const struct option builtin_format_patch_options[] = {
		{ OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
			    N_("use [PATCH n/m] even with a single patch"),
			    PARSE_OPT_NOARG, numbered_callback },
		{ OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
			    N_("use [PATCH] even with multiple patches"),
			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, no_numbered_callback },
		OPT_BOOL('s', "signoff", &do_signoff, N_("add Signed-off-by:")),
		OPT_BOOL(0, "stdout", &use_stdout,
			    N_("print patches to standard out")),
		OPT_BOOL(0, "cover-letter", &cover_letter,
			    N_("generate a cover letter")),
		OPT_BOOL(0, "numbered-files", &just_numbers,
			    N_("use simple number sequence for output file names")),
		OPT_STRING(0, "suffix", &fmt_patch_suffix, N_("sfx"),
			    N_("use <sfx> instead of '.patch'")),
		OPT_INTEGER(0, "start-number", &start_number,
			    N_("start numbering patches at <n> instead of 1")),
		OPT_INTEGER('v', "reroll-count", &reroll_count,
			    N_("mark the series as Nth re-roll")),
		{ OPTION_CALLBACK, 0, "rfc", &rev, NULL,
			    N_("Use [RFC PATCH] instead of [PATCH]"),
			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, rfc_callback },
		{ OPTION_CALLBACK, 0, "subject-prefix", &rev, N_("prefix"),
			    N_("Use [<prefix>] instead of [PATCH]"),
			    PARSE_OPT_NONEG, subject_prefix_callback },
		{ OPTION_CALLBACK, 'o', "output-directory", &output_directory,
			    N_("dir"), N_("store resulting files in <dir>"),
			    PARSE_OPT_NONEG, output_directory_callback },
		{ OPTION_CALLBACK, 'k', "keep-subject", &rev, NULL,
			    N_("don't strip/add [PATCH]"),
			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
		OPT_BOOL(0, "no-binary", &no_binary_diff,
			 N_("don't output binary diffs")),
		OPT_BOOL(0, "zero-commit", &zero_commit,
			 N_("output all-zero hash in From header")),
		OPT_BOOL(0, "ignore-if-in-upstream", &ignore_if_in_upstream,
			 N_("don't include a patch matching a commit upstream")),
		OPT_SET_INT_F('p', "no-stat", &use_patch_format,
			      N_("show patch format instead of default (patch + stat)"),
			      1, PARSE_OPT_NONEG),
		OPT_GROUP(N_("Messaging")),
		{ OPTION_CALLBACK, 0, "add-header", NULL, N_("header"),
			    N_("add email header"), 0, header_callback },
		{ OPTION_CALLBACK, 0, "to", NULL, N_("email"), N_("add To: header"),
			    0, to_callback },
		{ OPTION_CALLBACK, 0, "cc", NULL, N_("email"), N_("add Cc: header"),
			    0, cc_callback },
		{ OPTION_CALLBACK, 0, "from", &from, N_("ident"),
			    N_("set From address to <ident> (or committer ident if absent)"),
			    PARSE_OPT_OPTARG, from_callback },
		OPT_STRING(0, "in-reply-to", &in_reply_to, N_("message-id"),
			    N_("make first mail a reply to <message-id>")),
		{ OPTION_CALLBACK, 0, "attach", &rev, N_("boundary"),
			    N_("attach the patch"), PARSE_OPT_OPTARG,
			    attach_callback },
		{ OPTION_CALLBACK, 0, "inline", &rev, N_("boundary"),
			    N_("inline the patch"),
			    PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
			    inline_callback },
		{ OPTION_CALLBACK, 0, "thread", &thread, N_("style"),
			    N_("enable message threading, styles: shallow, deep"),
			    PARSE_OPT_OPTARG, thread_callback },
		OPT_STRING(0, "signature", &signature, N_("signature"),
			    N_("add a signature")),
		OPT_STRING(0, "base", &base_commit, N_("base-commit"),
			   N_("add prerequisite tree info to the patch series")),
		OPT_FILENAME(0, "signature-file", &signature_file,
				N_("add a signature from a file")),
		OPT__QUIET(&quiet, N_("don't print the patch filenames")),
		OPT_BOOL(0, "progress", &show_progress,
			 N_("show progress while generating patches")),
		OPT_CALLBACK(0, "interdiff", &idiff_prev, N_("rev"),
			     N_("show changes against <rev> in cover letter or single patch"),
			     parse_opt_object_name),
		OPT_STRING(0, "range-diff", &rdiff_prev, N_("refspec"),
			   N_("show changes against <refspec> in cover letter or single patch")),
		OPT_INTEGER(0, "creation-factor", &creation_factor,
			    N_("percentage by which creation is weighted")),
		OPT_END()
	};

	extra_hdr.strdup_strings = 1;
	extra_to.strdup_strings = 1;
	extra_cc.strdup_strings = 1;
	init_log_defaults();
	repo_init_revisions(the_repository, &rev, prefix);
	git_config(git_format_config, &rev);
	rev.commit_format = CMIT_FMT_EMAIL;
	rev.expand_tabs_in_log_default = 0;
	rev.verbose_header = 1;
	rev.diff = 1;
	rev.max_parents = 1;
	rev.diffopt.flags.recursive = 1;
	rev.subject_prefix = fmt_patch_subject_prefix;
	memset(&s_r_opt, 0, sizeof(s_r_opt));
	s_r_opt.def = "HEAD";
	s_r_opt.revarg_opt = REVARG_COMMITTISH;

	if (default_attach) {
		rev.mime_boundary = default_attach;
		rev.no_inline = 1;
	}

	/*
	 * Parse the arguments before setup_revisions(), or something
	 * like "git format-patch -o a123 HEAD^.." may fail; a123 is
	 * possibly a valid SHA1.
	 */
	argc = parse_options(argc, argv, prefix, builtin_format_patch_options,
			     builtin_format_patch_usage,
			     PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
			     PARSE_OPT_KEEP_DASHDASH);

	if (0 < reroll_count) {
		struct strbuf sprefix = STRBUF_INIT;
		strbuf_addf(&sprefix, "%s v%d",
			    rev.subject_prefix, reroll_count);
		rev.reroll_count = reroll_count;
		rev.subject_prefix = strbuf_detach(&sprefix, NULL);
	}

	for (i = 0; i < extra_hdr.nr; i++) {
		strbuf_addstr(&buf, extra_hdr.items[i].string);
		strbuf_addch(&buf, '\n');
	}

	if (extra_to.nr)
		strbuf_addstr(&buf, "To: ");
	for (i = 0; i < extra_to.nr; i++) {
		if (i)
			strbuf_addstr(&buf, "    ");
		strbuf_addstr(&buf, extra_to.items[i].string);
		if (i + 1 < extra_to.nr)
			strbuf_addch(&buf, ',');
		strbuf_addch(&buf, '\n');
	}

	if (extra_cc.nr)
		strbuf_addstr(&buf, "Cc: ");
	for (i = 0; i < extra_cc.nr; i++) {
		if (i)
			strbuf_addstr(&buf, "    ");
		strbuf_addstr(&buf, extra_cc.items[i].string);
		if (i + 1 < extra_cc.nr)
			strbuf_addch(&buf, ',');
		strbuf_addch(&buf, '\n');
	}

	rev.extra_headers = strbuf_detach(&buf, NULL);

	if (from) {
		if (split_ident_line(&rev.from_ident, from, strlen(from)))
			die(_("invalid ident line: %s"), from);
	}

	if (start_number < 0)
		start_number = 1;

	/*
	 * If numbered is set solely due to format.numbered in config,
	 * and it would conflict with --keep-subject (-k) from the
	 * command line, reset "numbered".
	 */
	if (numbered && keep_subject && !numbered_cmdline_opt)
		numbered = 0;

	if (numbered && keep_subject)
		die(_("-n and -k are mutually exclusive"));
	if (keep_subject && subject_prefix)
		die(_("--subject-prefix/--rfc and -k are mutually exclusive"));
	rev.preserve_subject = keep_subject;

	argc = setup_revisions(argc, argv, &rev, &s_r_opt);
	if (argc > 1)
		die(_("unrecognized argument: %s"), argv[1]);

	if (rev.diffopt.output_format & DIFF_FORMAT_NAME)
		die(_("--name-only does not make sense"));
	if (rev.diffopt.output_format & DIFF_FORMAT_NAME_STATUS)
		die(_("--name-status does not make sense"));
	if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF)
		die(_("--check does not make sense"));

	if (!use_patch_format &&
		(!rev.diffopt.output_format ||
		 rev.diffopt.output_format == DIFF_FORMAT_PATCH))
		rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY;
	if (!rev.diffopt.stat_width)
		rev.diffopt.stat_width = MAIL_DEFAULT_WRAP;

	/* Always generate a patch */
	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;

	rev.zero_commit = zero_commit;

	if (!rev.diffopt.flags.text && !no_binary_diff)
		rev.diffopt.flags.binary = 1;

	if (rev.show_notes)
		init_display_notes(&rev.notes_opt);

	if (!output_directory && !use_stdout)
		output_directory = config_output_directory;

	if (!use_stdout)
		output_directory = set_outdir(prefix, output_directory);
	else
		setup_pager();

	if (output_directory) {
		if (rev.diffopt.use_color != GIT_COLOR_ALWAYS)
			rev.diffopt.use_color = GIT_COLOR_NEVER;
		if (use_stdout)
			die(_("standard output, or directory, which one?"));
		if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
			die_errno(_("could not create directory '%s'"),
				  output_directory);
	}

	if (rev.pending.nr == 1) {
		int check_head = 0;

		if (rev.max_count < 0 && !rev.show_root_diff) {
			/*
			 * This is traditional behaviour of "git format-patch
			 * origin" that prepares what the origin side still
			 * does not have.
			 */
			rev.pending.objects[0].item->flags |= UNINTERESTING;
			add_head_to_pending(&rev);
			check_head = 1;
		}
		/*
		 * Otherwise, it is "format-patch -22 HEAD", and/or
		 * "format-patch --root HEAD".  The user wants
		 * get_revision() to do the usual traversal.
		 */

		if (!strcmp(rev.pending.objects[0].name, "HEAD"))
			check_head = 1;

		if (check_head) {
			const char *ref, *v;
			ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
						 NULL, NULL);
			if (ref && skip_prefix(ref, "refs/heads/", &v))
				branch_name = xstrdup(v);
			else
				branch_name = xstrdup(""); /* no branch */
		}
	}

	/*
	 * We cannot move this anywhere earlier because we do want to
	 * know if --root was given explicitly from the command line.
	 */
	rev.show_root_diff = 1;

	if (ignore_if_in_upstream) {
		/* Don't say anything if head and upstream are the same. */
		if (rev.pending.nr == 2) {
			struct object_array_entry *o = rev.pending.objects;
			if (oideq(&o[0].item->oid, &o[1].item->oid))
				goto done;
		}
		get_patch_ids(&rev, &ids);
	}

	if (prepare_revision_walk(&rev))
		die(_("revision walk setup failed"));
	rev.boundary = 1;
	while ((commit = get_revision(&rev)) != NULL) {
		if (commit->object.flags & BOUNDARY) {
			boundary_count++;
			origin = (boundary_count == 1) ? commit : NULL;
			continue;
		}

		if (ignore_if_in_upstream && has_commit_patch_id(commit, &ids))
			continue;

		nr++;
		REALLOC_ARRAY(list, nr);
		list[nr - 1] = commit;
	}
	if (nr == 0)
		/* nothing to do */
		goto done;
	total = nr;
	if (cover_letter == -1) {
		if (config_cover_letter == COVER_AUTO)
			cover_letter = (total > 1);
		else
			cover_letter = (config_cover_letter == COVER_ON);
	}
	if (!keep_subject && auto_number && (total > 1 || cover_letter))
		numbered = 1;
	if (numbered)
		rev.total = total + start_number - 1;

	if (idiff_prev.nr) {
		if (!cover_letter && total != 1)
			die(_("--interdiff requires --cover-letter or single patch"));
		rev.idiff_oid1 = &idiff_prev.oid[idiff_prev.nr - 1];
		rev.idiff_oid2 = get_commit_tree_oid(list[0]);
		rev.idiff_title = diff_title(&idiff_title, reroll_count,
					     _("Interdiff:"),
					     _("Interdiff against v%d:"));
	}

	if (creation_factor < 0)
		creation_factor = RANGE_DIFF_CREATION_FACTOR_DEFAULT;
	else if (!rdiff_prev)
		die(_("--creation-factor requires --range-diff"));

	if (rdiff_prev) {
		if (!cover_letter && total != 1)
			die(_("--range-diff requires --cover-letter or single patch"));

		infer_range_diff_ranges(&rdiff1, &rdiff2, rdiff_prev,
					origin, list[0]);
		rev.rdiff1 = rdiff1.buf;
		rev.rdiff2 = rdiff2.buf;
		rev.creation_factor = creation_factor;
		rev.rdiff_title = diff_title(&rdiff_title, reroll_count,
					     _("Range-diff:"),
					     _("Range-diff against v%d:"));
	}

	if (!signature) {
		; /* --no-signature inhibits all signatures */
	} else if (signature && signature != git_version_string) {
		; /* non-default signature already set */
	} else if (signature_file) {
		struct strbuf buf = STRBUF_INIT;

		if (strbuf_read_file(&buf, signature_file, 128) < 0)
			die_errno(_("unable to read signature file '%s'"), signature_file);
		signature = strbuf_detach(&buf, NULL);
	}

	memset(&bases, 0, sizeof(bases));
	if (base_commit || base_auto) {
		struct commit *base = get_base_commit(base_commit, list, nr);
		reset_revision_walk();
		clear_object_flags(UNINTERESTING);
		prepare_bases(&bases, base, list, nr);
	}

	if (in_reply_to || thread || cover_letter)
		rev.ref_message_ids = xcalloc(1, sizeof(struct string_list));
	if (in_reply_to) {
		const char *msgid = clean_message_id(in_reply_to);
		string_list_append(rev.ref_message_ids, msgid);
	}
	rev.numbered_files = just_numbers;
	rev.patch_suffix = fmt_patch_suffix;
	if (cover_letter) {
		if (thread)
			gen_message_id(&rev, "cover");
		make_cover_letter(&rev, use_stdout,
				  origin, nr, list, branch_name, quiet);
		print_bases(&bases, rev.diffopt.file);
		print_signature(rev.diffopt.file);
		total++;
		start_number--;
		/* interdiff/range-diff in cover-letter; omit from patches */
		rev.idiff_oid1 = NULL;
		rev.rdiff1 = NULL;
	}
	rev.add_signoff = do_signoff;

	if (show_progress)
		progress = start_delayed_progress(_("Generating patches"), total);
	while (0 <= --nr) {
		int shown;
		display_progress(progress, total - nr);
		commit = list[nr];
		rev.nr = total - nr + (start_number - 1);
		/* Make the second and subsequent mails replies to the first */
		if (thread) {
			/* Have we already had a message ID? */
			if (rev.message_id) {
				/*
				 * For deep threading: make every mail
				 * a reply to the previous one, no
				 * matter what other options are set.
				 *
				 * For shallow threading:
				 *
				 * Without --cover-letter and
				 * --in-reply-to, make every mail a
				 * reply to the one before.
				 *
				 * With --in-reply-to but no
				 * --cover-letter, make every mail a
				 * reply to the <reply-to>.
				 *
				 * With --cover-letter, make every
				 * mail but the cover letter a reply
				 * to the cover letter.  The cover
				 * letter is a reply to the
				 * --in-reply-to, if specified.
				 */
				if (thread == THREAD_SHALLOW
				    && rev.ref_message_ids->nr > 0
				    && (!cover_letter || rev.nr > 1))
					free(rev.message_id);
				else
					string_list_append(rev.ref_message_ids,
							   rev.message_id);
			}
			gen_message_id(&rev, oid_to_hex(&commit->object.oid));
		}

		if (!use_stdout &&
		    open_next_file(rev.numbered_files ? NULL : commit, NULL, &rev, quiet))
			die(_("failed to create output files"));
		shown = log_tree_commit(&rev, commit);
		free_commit_buffer(the_repository->parsed_objects,
				   commit);

		/* We put one extra blank line between formatted
		 * patches and this flag is used by log-tree code
		 * to see if it needs to emit a LF before showing
		 * the log; when using one file per patch, we do
		 * not want the extra blank line.
		 */
		if (!use_stdout)
			rev.shown_one = 0;
		if (shown) {
			print_bases(&bases, rev.diffopt.file);
			if (rev.mime_boundary)
				fprintf(rev.diffopt.file, "\n--%s%s--\n\n\n",
				       mime_boundary_leader,
				       rev.mime_boundary);
			else
				print_signature(rev.diffopt.file);
		}
		if (!use_stdout)
			fclose(rev.diffopt.file);
	}
	stop_progress(&progress);
	free(list);
	free(branch_name);
	string_list_clear(&extra_to, 0);
	string_list_clear(&extra_cc, 0);
	string_list_clear(&extra_hdr, 0);
	if (ignore_if_in_upstream)
		free_patch_ids(&ids);

done:
	oid_array_clear(&idiff_prev);
	strbuf_release(&idiff_title);
	strbuf_release(&rdiff1);
	strbuf_release(&rdiff2);
	strbuf_release(&rdiff_title);
	return 0;
}

static int add_pending_commit(const char *arg, struct rev_info *revs, int flags)
{
	struct object_id oid;
	if (get_oid(arg, &oid) == 0) {
		struct commit *commit = lookup_commit_reference(the_repository,
								&oid);
		if (commit) {
			commit->object.flags |= flags;
			add_pending_object(revs, &commit->object, arg);
			return 0;
		}
	}
	return -1;
}

static const char * const cherry_usage[] = {
	N_("git cherry [-v] [<upstream> [<head> [<limit>]]]"),
	NULL
};

static void print_commit(char sign, struct commit *commit, int verbose,
			 int abbrev, FILE *file)
{
	if (!verbose) {
		fprintf(file, "%c %s\n", sign,
		       find_unique_abbrev(&commit->object.oid, abbrev));
	} else {
		struct strbuf buf = STRBUF_INIT;
		pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
		fprintf(file, "%c %s %s\n", sign,
		       find_unique_abbrev(&commit->object.oid, abbrev),
		       buf.buf);
		strbuf_release(&buf);
	}
}

int cmd_cherry(int argc, const char **argv, const char *prefix)
{
	struct rev_info revs;
	struct patch_ids ids;
	struct commit *commit;
	struct commit_list *list = NULL;
	struct branch *current_branch;
	const char *upstream;
	const char *head = "HEAD";
	const char *limit = NULL;
	int verbose = 0, abbrev = 0;

	struct option options[] = {
		OPT__ABBREV(&abbrev),
		OPT__VERBOSE(&verbose, N_("be verbose")),
		OPT_END()
	};

	argc = parse_options(argc, argv, prefix, options, cherry_usage, 0);

	switch (argc) {
	case 3:
		limit = argv[2];
		/* FALLTHROUGH */
	case 2:
		head = argv[1];
		/* FALLTHROUGH */
	case 1:
		upstream = argv[0];
		break;
	default:
		current_branch = branch_get(NULL);
		upstream = branch_get_upstream(current_branch, NULL);
		if (!upstream) {
			fprintf(stderr, _("Could not find a tracked"
					" remote branch, please"
					" specify <upstream> manually.\n"));
			usage_with_options(cherry_usage, options);
		}
	}

	repo_init_revisions(the_repository, &revs, prefix);
	revs.max_parents = 1;

	if (add_pending_commit(head, &revs, 0))
		die(_("unknown commit %s"), head);
	if (add_pending_commit(upstream, &revs, UNINTERESTING))
		die(_("unknown commit %s"), upstream);

	/* Don't say anything if head and upstream are the same. */
	if (revs.pending.nr == 2) {
		struct object_array_entry *o = revs.pending.objects;
		if (oideq(&o[0].item->oid, &o[1].item->oid))
			return 0;
	}

	get_patch_ids(&revs, &ids);

	if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
		die(_("unknown commit %s"), limit);

	/* reverse the list of commits */
	if (prepare_revision_walk(&revs))
		die(_("revision walk setup failed"));
	while ((commit = get_revision(&revs)) != NULL) {
		commit_list_insert(commit, &list);
	}

	while (list) {
		char sign = '+';

		commit = list->item;
		if (has_commit_patch_id(commit, &ids))
			sign = '-';
		print_commit(sign, commit, verbose, abbrev, revs.diffopt.file);
		list = list->next;
	}

	free_patch_ids(&ids);
	return 0;
}
