chore(3p/git): Unvendor git and track patches instead r/2903

This was vendored a long time ago under the expectation that keeping
it in sync with cgit would be easier this way, but it has proven not
to be a big issue.

On the other hand, a vendored copy of git is an annoying maintenance
burden. It is much easier to rebase the single (dottime) patch that we
have.

This removes the vendored copy of git and instead passes the git
source code to cgit via `pkgs.srcOnly`, which includes the applied
patch so that cgit can continue rendering dottime.

Change-Id: If31f62dea7ce688fd1b9050204e9378019775f2b

1 files changed, 0 insertions, 1715 deletions

diff --git a/third_party/git/builtin/merge.c b/third_party/git/builtin/merge.c
deleted file mode 100644
index 9d5359edc2f7..000000000000
--- a/third_party/git/builtin/merge.c
+++ /dev/null
@@ -1,1715 +0,0 @@
-/*
- * Builtin "git merge"
- *
- * Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
- *
- * Based on git-merge.sh by Junio C Hamano.
- */
-
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
-#include "cache.h"
-#include "config.h"
-#include "parse-options.h"
-#include "builtin.h"
-#include "lockfile.h"
-#include "run-command.h"
-#include "diff.h"
-#include "refs.h"
-#include "refspec.h"
-#include "commit.h"
-#include "diffcore.h"
-#include "revision.h"
-#include "unpack-trees.h"
-#include "cache-tree.h"
-#include "dir.h"
-#include "utf8.h"
-#include "log-tree.h"
-#include "color.h"
-#include "rerere.h"
-#include "help.h"
-#include "merge-recursive.h"
-#include "resolve-undo.h"
-#include "remote.h"
-#include "fmt-merge-msg.h"
-#include "gpg-interface.h"
-#include "sequencer.h"
-#include "string-list.h"
-#include "packfile.h"
-#include "tag.h"
-#include "alias.h"
-#include "branch.h"
-#include "commit-reach.h"
-#include "wt-status.h"
-#include "commit-graph.h"
-
-#define DEFAULT_TWOHEAD (1<<0)
-#define DEFAULT_OCTOPUS (1<<1)
-#define NO_FAST_FORWARD (1<<2)
-#define NO_TRIVIAL      (1<<3)
-
-struct strategy {
-	const char *name;
-	unsigned attr;
-};
-
-static const char * const builtin_merge_usage[] = {
-	N_("git merge [<options>] [<commit>...]"),
-	N_("git merge --abort"),
-	N_("git merge --continue"),
-	NULL
-};
-
-static int show_diffstat = 1, shortlog_len = -1, squash;
-static int option_commit = -1;
-static int option_edit = -1;
-static int allow_trivial = 1, have_message, verify_signatures;
-static int check_trust_level = 1;
-static int overwrite_ignore = 1;
-static struct strbuf merge_msg = STRBUF_INIT;
-static struct strategy **use_strategies;
-static size_t use_strategies_nr, use_strategies_alloc;
-static const char **xopts;
-static size_t xopts_nr, xopts_alloc;
-static const char *branch;
-static char *branch_mergeoptions;
-static int verbosity;
-static int allow_rerere_auto;
-static int abort_current_merge;
-static int quit_current_merge;
-static int continue_current_merge;
-static int allow_unrelated_histories;
-static int show_progress = -1;
-static int default_to_upstream = 1;
-static int signoff;
-static const char *sign_commit;
-static int autostash;
-static int no_verify;
-
-static struct strategy all_strategy[] = {
-	{ "recursive",  DEFAULT_TWOHEAD | NO_TRIVIAL },
-	{ "octopus",    DEFAULT_OCTOPUS },
-	{ "resolve",    0 },
-	{ "ours",       NO_FAST_FORWARD | NO_TRIVIAL },
-	{ "subtree",    NO_FAST_FORWARD | NO_TRIVIAL },
-};
-
-static const char *pull_twohead, *pull_octopus;
-
-enum ff_type {
-	FF_NO,
-	FF_ALLOW,
-	FF_ONLY
-};
-
-static enum ff_type fast_forward = FF_ALLOW;
-
-static const char *cleanup_arg;
-static enum commit_msg_cleanup_mode cleanup_mode;
-
-static int option_parse_message(const struct option *opt,
-				const char *arg, int unset)
-{
-	struct strbuf *buf = opt->value;
-
-	if (unset)
-		strbuf_setlen(buf, 0);
-	else if (arg) {
-		strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
-		have_message = 1;
-	} else
-		return error(_("switch `m' requires a value"));
-	return 0;
-}
-
-static enum parse_opt_result option_read_message(struct parse_opt_ctx_t *ctx,
-						 const struct option *opt,
-						 const char *arg_not_used,
-						 int unset)
-{
-	struct strbuf *buf = opt->value;
-	const char *arg;
-
-	BUG_ON_OPT_ARG(arg_not_used);
-	if (unset)
-		BUG("-F cannot be negated");
-
-	if (ctx->opt) {
-		arg = ctx->opt;
-		ctx->opt = NULL;
-	} else if (ctx->argc > 1) {
-		ctx->argc--;
-		arg = *++ctx->argv;
-	} else
-		return error(_("option `%s' requires a value"), opt->long_name);
-
-	if (buf->len)
-		strbuf_addch(buf, '\n');
-	if (ctx->prefix && !is_absolute_path(arg))
-		arg = prefix_filename(ctx->prefix, arg);
-	if (strbuf_read_file(buf, arg, 0) < 0)
-		return error(_("could not read file '%s'"), arg);
-	have_message = 1;
-
-	return 0;
-}
-
-static struct strategy *get_strategy(const char *name)
-{
-	int i;
-	struct strategy *ret;
-	static struct cmdnames main_cmds, other_cmds;
-	static int loaded;
-
-	if (!name)
-		return NULL;
-
-	for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
-		if (!strcmp(name, all_strategy[i].name))
-			return &all_strategy[i];
-
-	if (!loaded) {
-		struct cmdnames not_strategies;
-		loaded = 1;
-
-		memset(&not_strategies, 0, sizeof(struct cmdnames));
-		load_command_list("git-merge-", &main_cmds, &other_cmds);
-		for (i = 0; i < main_cmds.cnt; i++) {
-			int j, found = 0;
-			struct cmdname *ent = main_cmds.names[i];
-			for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
-				if (!strncmp(ent->name, all_strategy[j].name, ent->len)
-						&& !all_strategy[j].name[ent->len])
-					found = 1;
-			if (!found)
-				add_cmdname(&not_strategies, ent->name, ent->len);
-		}
-		exclude_cmds(&main_cmds, &not_strategies);
-	}
-	if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
-		fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
-		fprintf(stderr, _("Available strategies are:"));
-		for (i = 0; i < main_cmds.cnt; i++)
-			fprintf(stderr, " %s", main_cmds.names[i]->name);
-		fprintf(stderr, ".\n");
-		if (other_cmds.cnt) {
-			fprintf(stderr, _("Available custom strategies are:"));
-			for (i = 0; i < other_cmds.cnt; i++)
-				fprintf(stderr, " %s", other_cmds.names[i]->name);
-			fprintf(stderr, ".\n");
-		}
-		exit(1);
-	}
-
-	ret = xcalloc(1, sizeof(struct strategy));
-	ret->name = xstrdup(name);
-	ret->attr = NO_TRIVIAL;
-	return ret;
-}
-
-static void append_strategy(struct strategy *s)
-{
-	ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
-	use_strategies[use_strategies_nr++] = s;
-}
-
-static int option_parse_strategy(const struct option *opt,
-				 const char *name, int unset)
-{
-	if (unset)
-		return 0;
-
-	append_strategy(get_strategy(name));
-	return 0;
-}
-
-static int option_parse_x(const struct option *opt,
-			  const char *arg, int unset)
-{
-	if (unset)
-		return 0;
-
-	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
-	xopts[xopts_nr++] = xstrdup(arg);
-	return 0;
-}
-
-static int option_parse_n(const struct option *opt,
-			  const char *arg, int unset)
-{
-	BUG_ON_OPT_ARG(arg);
-	show_diffstat = unset;
-	return 0;
-}
-
-static struct option builtin_merge_options[] = {
-	OPT_CALLBACK_F('n', NULL, NULL, NULL,
-		N_("do not show a diffstat at the end of the merge"),
-		PARSE_OPT_NOARG, option_parse_n),
-	OPT_BOOL(0, "stat", &show_diffstat,
-		N_("show a diffstat at the end of the merge")),
-	OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
-	{ OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
-	  N_("add (at most <n>) entries from shortlog to merge commit message"),
-	  PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
-	OPT_BOOL(0, "squash", &squash,
-		N_("create a single commit instead of doing a merge")),
-	OPT_BOOL(0, "commit", &option_commit,
-		N_("perform a commit if the merge succeeds (default)")),
-	OPT_BOOL('e', "edit", &option_edit,
-		N_("edit message before committing")),
-	OPT_CLEANUP(&cleanup_arg),
-	OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
-	OPT_SET_INT_F(0, "ff-only", &fast_forward,
-		      N_("abort if fast-forward is not possible"),
-		      FF_ONLY, PARSE_OPT_NONEG),
-	OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
-	OPT_BOOL(0, "verify-signatures", &verify_signatures,
-		N_("verify that the named commit has a valid GPG signature")),
-	OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
-		N_("merge strategy to use"), option_parse_strategy),
-	OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
-		N_("option for selected merge strategy"), option_parse_x),
-	OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
-		N_("merge commit message (for a non-fast-forward merge)"),
-		option_parse_message),
-	{ OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
-		N_("read message from file"), PARSE_OPT_NONEG,
-		NULL, 0, option_read_message },
-	OPT__VERBOSITY(&verbosity),
-	OPT_BOOL(0, "abort", &abort_current_merge,
-		N_("abort the current in-progress merge")),
-	OPT_BOOL(0, "quit", &quit_current_merge,
-		N_("--abort but leave index and working tree alone")),
-	OPT_BOOL(0, "continue", &continue_current_merge,
-		N_("continue the current in-progress merge")),
-	OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
-		 N_("allow merging unrelated histories")),
-	OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
-	{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
-	  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
-	OPT_AUTOSTASH(&autostash),
-	OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
-	OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
-	OPT_BOOL(0, "no-verify", &no_verify, N_("bypass pre-merge-commit and commit-msg hooks")),
-	OPT_END()
-};
-
-static int save_state(struct object_id *stash)
-{
-	int len;
-	struct child_process cp = CHILD_PROCESS_INIT;
-	struct strbuf buffer = STRBUF_INIT;
-	const char *argv[] = {"stash", "create", NULL};
-	int rc = -1;
-
-	cp.argv = argv;
-	cp.out = -1;
-	cp.git_cmd = 1;
-
-	if (start_command(&cp))
-		die(_("could not run stash."));
-	len = strbuf_read(&buffer, cp.out, 1024);
-	close(cp.out);
-
-	if (finish_command(&cp) || len < 0)
-		die(_("stash failed"));
-	else if (!len)		/* no changes */
-		goto out;
-	strbuf_setlen(&buffer, buffer.len-1);
-	if (get_oid(buffer.buf, stash))
-		die(_("not a valid object: %s"), buffer.buf);
-	rc = 0;
-out:
-	strbuf_release(&buffer);
-	return rc;
-}
-
-static void read_empty(const struct object_id *oid, int verbose)
-{
-	int i = 0;
-	const char *args[7];
-
-	args[i++] = "read-tree";
-	if (verbose)
-		args[i++] = "-v";
-	args[i++] = "-m";
-	args[i++] = "-u";
-	args[i++] = empty_tree_oid_hex();
-	args[i++] = oid_to_hex(oid);
-	args[i] = NULL;
-
-	if (run_command_v_opt(args, RUN_GIT_CMD))
-		die(_("read-tree failed"));
-}
-
-static void reset_hard(const struct object_id *oid, int verbose)
-{
-	int i = 0;
-	const char *args[6];
-
-	args[i++] = "read-tree";
-	if (verbose)
-		args[i++] = "-v";
-	args[i++] = "--reset";
-	args[i++] = "-u";
-	args[i++] = oid_to_hex(oid);
-	args[i] = NULL;
-
-	if (run_command_v_opt(args, RUN_GIT_CMD))
-		die(_("read-tree failed"));
-}
-
-static void restore_state(const struct object_id *head,
-			  const struct object_id *stash)
-{
-	struct strbuf sb = STRBUF_INIT;
-	const char *args[] = { "stash", "apply", NULL, NULL };
-
-	if (is_null_oid(stash))
-		return;
-
-	reset_hard(head, 1);
-
-	args[2] = oid_to_hex(stash);
-
-	/*
-	 * It is OK to ignore error here, for example when there was
-	 * nothing to restore.
-	 */
-	run_command_v_opt(args, RUN_GIT_CMD);
-
-	strbuf_release(&sb);
-	refresh_cache(REFRESH_QUIET);
-}
-
-/* This is called when no merge was necessary. */
-static void finish_up_to_date(const char *msg)
-{
-	if (verbosity >= 0)
-		printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
-	remove_merge_branch_state(the_repository);
-}
-
-static void squash_message(struct commit *commit, struct commit_list *remoteheads)
-{
-	struct rev_info rev;
-	struct strbuf out = STRBUF_INIT;
-	struct commit_list *j;
-	struct pretty_print_context ctx = {0};
-
-	printf(_("Squash commit -- not updating HEAD\n"));
-
-	repo_init_revisions(the_repository, &rev, NULL);
-	rev.ignore_merges = 1;
-	rev.commit_format = CMIT_FMT_MEDIUM;
-
-	commit->object.flags |= UNINTERESTING;
-	add_pending_object(&rev, &commit->object, NULL);
-
-	for (j = remoteheads; j; j = j->next)
-		add_pending_object(&rev, &j->item->object, NULL);
-
-	setup_revisions(0, NULL, &rev, NULL);
-	if (prepare_revision_walk(&rev))
-		die(_("revision walk setup failed"));
-
-	ctx.abbrev = rev.abbrev;
-	ctx.date_mode = rev.date_mode;
-	ctx.fmt = rev.commit_format;
-
-	strbuf_addstr(&out, "Squashed commit of the following:\n");
-	while ((commit = get_revision(&rev)) != NULL) {
-		strbuf_addch(&out, '\n');
-		strbuf_addf(&out, "commit %s\n",
-			oid_to_hex(&commit->object.oid));
-		pretty_print_commit(&ctx, commit, &out);
-	}
-	write_file_buf(git_path_squash_msg(the_repository), out.buf, out.len);
-	strbuf_release(&out);
-}
-
-static void finish(struct commit *head_commit,
-		   struct commit_list *remoteheads,
-		   const struct object_id *new_head, const char *msg)
-{
-	struct strbuf reflog_message = STRBUF_INIT;
-	const struct object_id *head = &head_commit->object.oid;
-
-	if (!msg)
-		strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
-	else {
-		if (verbosity >= 0)
-			printf("%s\n", msg);
-		strbuf_addf(&reflog_message, "%s: %s",
-			getenv("GIT_REFLOG_ACTION"), msg);
-	}
-	if (squash) {
-		squash_message(head_commit, remoteheads);
-	} else {
-		if (verbosity >= 0 && !merge_msg.len)
-			printf(_("No merge message -- not updating HEAD\n"));
-		else {
-			update_ref(reflog_message.buf, "HEAD", new_head, head,
-				   0, UPDATE_REFS_DIE_ON_ERR);
-			/*
-			 * We ignore errors in 'gc --auto', since the
-			 * user should see them.
-			 */
-			close_object_store(the_repository->objects);
-			run_auto_maintenance(verbosity < 0);
-		}
-	}
-	if (new_head && show_diffstat) {
-		struct diff_options opts;
-		repo_diff_setup(the_repository, &opts);
-		opts.stat_width = -1; /* use full terminal width */
-		opts.stat_graph_width = -1; /* respect statGraphWidth config */
-		opts.output_format |=
-			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
-		opts.detect_rename = DIFF_DETECT_RENAME;
-		diff_setup_done(&opts);
-		diff_tree_oid(head, new_head, "", &opts);
-		diffcore_std(&opts);
-		diff_flush(&opts);
-	}
-
-	/* Run a post-merge hook */
-	run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
-
-	apply_autostash(git_path_merge_autostash(the_repository));
-	strbuf_release(&reflog_message);
-}
-
-/* Get the name for the merge commit's message. */
-static void merge_name(const char *remote, struct strbuf *msg)
-{
-	struct commit *remote_head;
-	struct object_id branch_head;
-	struct strbuf buf = STRBUF_INIT;
-	struct strbuf bname = STRBUF_INIT;
-	struct merge_remote_desc *desc;
-	const char *ptr;
-	char *found_ref;
-	int len, early;
-
-	strbuf_branchname(&bname, remote, 0);
-	remote = bname.buf;
-
-	oidclr(&branch_head);
-	remote_head = get_merge_parent(remote);
-	if (!remote_head)
-		die(_("'%s' does not point to a commit"), remote);
-
-	if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref, 0) > 0) {
-		if (starts_with(found_ref, "refs/heads/")) {
-			strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
-				    oid_to_hex(&branch_head), remote);
-			goto cleanup;
-		}
-		if (starts_with(found_ref, "refs/tags/")) {
-			strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
-				    oid_to_hex(&branch_head), remote);
-			goto cleanup;
-		}
-		if (starts_with(found_ref, "refs/remotes/")) {
-			strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
-				    oid_to_hex(&branch_head), remote);
-			goto cleanup;
-		}
-	}
-
-	/* See if remote matches <name>^^^.. or <name>~<number> */
-	for (len = 0, ptr = remote + strlen(remote);
-	     remote < ptr && ptr[-1] == '^';
-	     ptr--)
-		len++;
-	if (len)
-		early = 1;
-	else {
-		early = 0;
-		ptr = strrchr(remote, '~');
-		if (ptr) {
-			int seen_nonzero = 0;
-
-			len++; /* count ~ */
-			while (*++ptr && isdigit(*ptr)) {
-				seen_nonzero |= (*ptr != '0');
-				len++;
-			}
-			if (*ptr)
-				len = 0; /* not ...~<number> */
-			else if (seen_nonzero)
-				early = 1;
-			else if (len == 1)
-				early = 1; /* "name~" is "name~1"! */
-		}
-	}
-	if (len) {
-		struct strbuf truname = STRBUF_INIT;
-		strbuf_addf(&truname, "refs/heads/%s", remote);
-		strbuf_setlen(&truname, truname.len - len);
-		if (ref_exists(truname.buf)) {
-			strbuf_addf(msg,
-				    "%s\t\tbranch '%s'%s of .\n",
-				    oid_to_hex(&remote_head->object.oid),
-				    truname.buf + 11,
-				    (early ? " (early part)" : ""));
-			strbuf_release(&truname);
-			goto cleanup;
-		}
-		strbuf_release(&truname);
-	}
-
-	desc = merge_remote_util(remote_head);
-	if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
-		strbuf_addf(msg, "%s\t\t%s '%s'\n",
-			    oid_to_hex(&desc->obj->oid),
-			    type_name(desc->obj->type),
-			    remote);
-		goto cleanup;
-	}
-
-	strbuf_addf(msg, "%s\t\tcommit '%s'\n",
-		oid_to_hex(&remote_head->object.oid), remote);
-cleanup:
-	strbuf_release(&buf);
-	strbuf_release(&bname);
-}
-
-static void parse_branch_merge_options(char *bmo)
-{
-	const char **argv;
-	int argc;
-
-	if (!bmo)
-		return;
-	argc = split_cmdline(bmo, &argv);
-	if (argc < 0)
-		die(_("Bad branch.%s.mergeoptions string: %s"), branch,
-		    _(split_cmdline_strerror(argc)));
-	REALLOC_ARRAY(argv, argc + 2);
-	MOVE_ARRAY(argv + 1, argv, argc + 1);
-	argc++;
-	argv[0] = "branch.*.mergeoptions";
-	parse_options(argc, argv, NULL, builtin_merge_options,
-		      builtin_merge_usage, 0);
-	free(argv);
-}
-
-static int git_merge_config(const char *k, const char *v, void *cb)
-{
-	int status;
-	const char *str;
-
-	if (branch &&
-	    skip_prefix(k, "branch.", &str) &&
-	    skip_prefix(str, branch, &str) &&
-	    !strcmp(str, ".mergeoptions")) {
-		free(branch_mergeoptions);
-		branch_mergeoptions = xstrdup(v);
-		return 0;
-	}
-
-	if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
-		show_diffstat = git_config_bool(k, v);
-	else if (!strcmp(k, "merge.verifysignatures"))
-		verify_signatures = git_config_bool(k, v);
-	else if (!strcmp(k, "pull.twohead"))
-		return git_config_string(&pull_twohead, k, v);
-	else if (!strcmp(k, "pull.octopus"))
-		return git_config_string(&pull_octopus, k, v);
-	else if (!strcmp(k, "commit.cleanup"))
-		return git_config_string(&cleanup_arg, k, v);
-	else if (!strcmp(k, "merge.ff")) {
-		int boolval = git_parse_maybe_bool(v);
-		if (0 <= boolval) {
-			fast_forward = boolval ? FF_ALLOW : FF_NO;
-		} else if (v && !strcmp(v, "only")) {
-			fast_forward = FF_ONLY;
-		} /* do not barf on values from future versions of git */
-		return 0;
-	} else if (!strcmp(k, "merge.defaulttoupstream")) {
-		default_to_upstream = git_config_bool(k, v);
-		return 0;
-	} else if (!strcmp(k, "commit.gpgsign")) {
-		sign_commit = git_config_bool(k, v) ? "" : NULL;
-		return 0;
-	} else if (!strcmp(k, "gpg.mintrustlevel")) {
-		check_trust_level = 0;
-	} else if (!strcmp(k, "merge.autostash")) {
-		autostash = git_config_bool(k, v);
-		return 0;
-	}
-
-	status = fmt_merge_msg_config(k, v, cb);
-	if (status)
-		return status;
-	status = git_gpg_config(k, v, NULL);
-	if (status)
-		return status;
-	return git_diff_ui_config(k, v, cb);
-}
-
-static int read_tree_trivial(struct object_id *common, struct object_id *head,
-			     struct object_id *one)
-{
-	int i, nr_trees = 0;
-	struct tree *trees[MAX_UNPACK_TREES];
-	struct tree_desc t[MAX_UNPACK_TREES];
-	struct unpack_trees_options opts;
-
-	memset(&opts, 0, sizeof(opts));
-	opts.head_idx = 2;
-	opts.src_index = &the_index;
-	opts.dst_index = &the_index;
-	opts.update = 1;
-	opts.verbose_update = 1;
-	opts.trivial_merges_only = 1;
-	opts.merge = 1;
-	trees[nr_trees] = parse_tree_indirect(common);
-	if (!trees[nr_trees++])
-		return -1;
-	trees[nr_trees] = parse_tree_indirect(head);
-	if (!trees[nr_trees++])
-		return -1;
-	trees[nr_trees] = parse_tree_indirect(one);
-	if (!trees[nr_trees++])
-		return -1;
-	opts.fn = threeway_merge;
-	cache_tree_free(&active_cache_tree);
-	for (i = 0; i < nr_trees; i++) {
-		parse_tree(trees[i]);
-		init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
-	}
-	if (unpack_trees(nr_trees, t, &opts))
-		return -1;
-	return 0;
-}
-
-static void write_tree_trivial(struct object_id *oid)
-{
-	if (write_cache_as_tree(oid, 0, NULL))
-		die(_("git write-tree failed to write a tree"));
-}
-
-static int try_merge_strategy(const char *strategy, struct commit_list *common,
-			      struct commit_list *remoteheads,
-			      struct commit *head)
-{
-	const char *head_arg = "HEAD";
-
-	if (refresh_and_write_cache(REFRESH_QUIET, SKIP_IF_UNCHANGED, 0) < 0)
-		return error(_("Unable to write index."));
-
-	if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
-		struct lock_file lock = LOCK_INIT;
-		int clean, x;
-		struct commit *result;
-		struct commit_list *reversed = NULL;
-		struct merge_options o;
-		struct commit_list *j;
-
-		if (remoteheads->next) {
-			error(_("Not handling anything other than two heads merge."));
-			return 2;
-		}
-
-		init_merge_options(&o, the_repository);
-		if (!strcmp(strategy, "subtree"))
-			o.subtree_shift = "";
-
-		o.show_rename_progress =
-			show_progress == -1 ? isatty(2) : show_progress;
-
-		for (x = 0; x < xopts_nr; x++)
-			if (parse_merge_opt(&o, xopts[x]))
-				die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
-
-		o.branch1 = head_arg;
-		o.branch2 = merge_remote_util(remoteheads->item)->name;
-
-		for (j = common; j; j = j->next)
-			commit_list_insert(j->item, &reversed);
-
-		hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
-		clean = merge_recursive(&o, head,
-				remoteheads->item, reversed, &result);
-		if (clean < 0)
-			exit(128);
-		if (write_locked_index(&the_index, &lock,
-				       COMMIT_LOCK | SKIP_IF_UNCHANGED))
-			die(_("unable to write %s"), get_index_file());
-		return clean ? 0 : 1;
-	} else {
-		return try_merge_command(the_repository,
-					 strategy, xopts_nr, xopts,
-					 common, head_arg, remoteheads);
-	}
-}
-
-static void count_diff_files(struct diff_queue_struct *q,
-			     struct diff_options *opt, void *data)
-{
-	int *count = data;
-
-	(*count) += q->nr;
-}
-
-static int count_unmerged_entries(void)
-{
-	int i, ret = 0;
-
-	for (i = 0; i < active_nr; i++)
-		if (ce_stage(active_cache[i]))
-			ret++;
-
-	return ret;
-}
-
-static void add_strategies(const char *string, unsigned attr)
-{
-	int i;
-
-	if (string) {
-		struct string_list list = STRING_LIST_INIT_DUP;
-		struct string_list_item *item;
-		string_list_split(&list, string, ' ', -1);
-		for_each_string_list_item(item, &list)
-			append_strategy(get_strategy(item->string));
-		string_list_clear(&list, 0);
-		return;
-	}
-	for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
-		if (all_strategy[i].attr & attr)
-			append_strategy(&all_strategy[i]);
-
-}
-
-static void read_merge_msg(struct strbuf *msg)
-{
-	const char *filename = git_path_merge_msg(the_repository);
-	strbuf_reset(msg);
-	if (strbuf_read_file(msg, filename, 0) < 0)
-		die_errno(_("Could not read from '%s'"), filename);
-}
-
-static void write_merge_state(struct commit_list *);
-static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
-{
-	if (err_msg)
-		error("%s", err_msg);
-	fprintf(stderr,
-		_("Not committing merge; use 'git commit' to complete the merge.\n"));
-	write_merge_state(remoteheads);
-	exit(1);
-}
-
-static const char merge_editor_comment[] =
-N_("Please enter a commit message to explain why this merge is necessary,\n"
-   "especially if it merges an updated upstream into a topic branch.\n"
-   "\n");
-
-static const char scissors_editor_comment[] =
-N_("An empty message aborts the commit.\n");
-
-static const char no_scissors_editor_comment[] =
-N_("Lines starting with '%c' will be ignored, and an empty message aborts\n"
-   "the commit.\n");
-
-static void write_merge_heads(struct commit_list *);
-static void prepare_to_commit(struct commit_list *remoteheads)
-{
-	struct strbuf msg = STRBUF_INIT;
-	const char *index_file = get_index_file();
-
-	if (!no_verify && run_commit_hook(0 < option_edit, index_file, "pre-merge-commit", NULL))
-		abort_commit(remoteheads, NULL);
-	/*
-	 * Re-read the index as pre-merge-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.
-	 */
-	if (find_hook("pre-merge-commit"))
-		discard_cache();
-	read_cache_from(index_file);
-	strbuf_addbuf(&msg, &merge_msg);
-	if (squash)
-		BUG("the control must not reach here under --squash");
-	if (0 < option_edit) {
-		strbuf_addch(&msg, '\n');
-		if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS) {
-			wt_status_append_cut_line(&msg);
-			strbuf_commented_addf(&msg, "\n");
-		}
-		strbuf_commented_addf(&msg, _(merge_editor_comment));
-		strbuf_commented_addf(&msg, _(cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS ?
-			scissors_editor_comment :
-			no_scissors_editor_comment), comment_line_char);
-	}
-	if (signoff)
-		append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
-	write_merge_heads(remoteheads);
-	write_file_buf(git_path_merge_msg(the_repository), msg.buf, msg.len);
-	if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
-			    git_path_merge_msg(the_repository), "merge", NULL))
-		abort_commit(remoteheads, NULL);
-	if (0 < option_edit) {
-		if (launch_editor(git_path_merge_msg(the_repository), NULL, NULL))
-			abort_commit(remoteheads, NULL);
-	}
-
-	if (!no_verify && run_commit_hook(0 < option_edit, get_index_file(),
-					  "commit-msg",
-					  git_path_merge_msg(the_repository), NULL))
-		abort_commit(remoteheads, NULL);
-
-	read_merge_msg(&msg);
-	cleanup_message(&msg, cleanup_mode, 0);
-	if (!msg.len)
-		abort_commit(remoteheads, _("Empty commit message."));
-	strbuf_release(&merge_msg);
-	strbuf_addbuf(&merge_msg, &msg);
-	strbuf_release(&msg);
-}
-
-static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
-{
-	struct object_id result_tree, result_commit;
-	struct commit_list *parents, **pptr = &parents;
-
-	if (refresh_and_write_cache(REFRESH_QUIET, SKIP_IF_UNCHANGED, 0) < 0)
-		return error(_("Unable to write index."));
-
-	write_tree_trivial(&result_tree);
-	printf(_("Wonderful.\n"));
-	pptr = commit_list_append(head, pptr);
-	pptr = commit_list_append(remoteheads->item, pptr);
-	prepare_to_commit(remoteheads);
-	if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
-			&result_commit, NULL, sign_commit))
-		die(_("failed to write commit object"));
-	finish(head, remoteheads, &result_commit, "In-index merge");
-	remove_merge_branch_state(the_repository);
-	return 0;
-}
-
-static int finish_automerge(struct commit *head,
-			    int head_subsumed,
-			    struct commit_list *common,
-			    struct commit_list *remoteheads,
-			    struct object_id *result_tree,
-			    const char *wt_strategy)
-{
-	struct commit_list *parents = NULL;
-	struct strbuf buf = STRBUF_INIT;
-	struct object_id result_commit;
-
-	write_tree_trivial(result_tree);
-	free_commit_list(common);
-	parents = remoteheads;
-	if (!head_subsumed || fast_forward == FF_NO)
-		commit_list_insert(head, &parents);
-	prepare_to_commit(remoteheads);
-	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
-			&result_commit, NULL, sign_commit))
-		die(_("failed to write commit object"));
-	strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
-	finish(head, remoteheads, &result_commit, buf.buf);
-	strbuf_release(&buf);
-	remove_merge_branch_state(the_repository);
-	return 0;
-}
-
-static int suggest_conflicts(void)
-{
-	const char *filename;
-	FILE *fp;
-	struct strbuf msgbuf = STRBUF_INIT;
-
-	filename = git_path_merge_msg(the_repository);
-	fp = xfopen(filename, "a");
-
-	/*
-	 * We can't use cleanup_mode because if we're not using the editor,
-	 * get_cleanup_mode will return COMMIT_MSG_CLEANUP_SPACE instead, even
-	 * though the message is meant to be processed later by git-commit.
-	 * Thus, we will get the cleanup mode which is returned when we _are_
-	 * using an editor.
-	 */
-	append_conflicts_hint(&the_index, &msgbuf,
-			      get_cleanup_mode(cleanup_arg, 1));
-	fputs(msgbuf.buf, fp);
-	strbuf_release(&msgbuf);
-	fclose(fp);
-	repo_rerere(the_repository, allow_rerere_auto);
-	printf(_("Automatic merge failed; "
-			"fix conflicts and then commit the result.\n"));
-	return 1;
-}
-
-static int evaluate_result(void)
-{
-	int cnt = 0;
-	struct rev_info rev;
-
-	/* Check how many files differ. */
-	repo_init_revisions(the_repository, &rev, "");
-	setup_revisions(0, NULL, &rev, NULL);
-	rev.diffopt.output_format |=
-		DIFF_FORMAT_CALLBACK;
-	rev.diffopt.format_callback = count_diff_files;
-	rev.diffopt.format_callback_data = &cnt;
-	run_diff_files(&rev, 0);
-
-	/*
-	 * Check how many unmerged entries are
-	 * there.
-	 */
-	cnt += count_unmerged_entries();
-
-	return cnt;
-}
-
-/*
- * Pretend as if the user told us to merge with the remote-tracking
- * branch we have for the upstream of the current branch
- */
-static int setup_with_upstream(const char ***argv)
-{
-	struct branch *branch = branch_get(NULL);
-	int i;
-	const char **args;
-
-	if (!branch)
-		die(_("No current branch."));
-	if (!branch->remote_name)
-		die(_("No remote for the current branch."));
-	if (!branch->merge_nr)
-		die(_("No default upstream defined for the current branch."));
-
-	args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
-	for (i = 0; i < branch->merge_nr; i++) {
-		if (!branch->merge[i]->dst)
-			die(_("No remote-tracking branch for %s from %s"),
-			    branch->merge[i]->src, branch->remote_name);
-		args[i] = branch->merge[i]->dst;
-	}
-	args[i] = NULL;
-	*argv = args;
-	return i;
-}
-
-static void write_merge_heads(struct commit_list *remoteheads)
-{
-	struct commit_list *j;
-	struct strbuf buf = STRBUF_INIT;
-
-	for (j = remoteheads; j; j = j->next) {
-		struct object_id *oid;
-		struct commit *c = j->item;
-		struct merge_remote_desc *desc;
-
-		desc = merge_remote_util(c);
-		if (desc && desc->obj) {
-			oid = &desc->obj->oid;
-		} else {
-			oid = &c->object.oid;
-		}
-		strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
-	}
-	write_file_buf(git_path_merge_head(the_repository), buf.buf, buf.len);
-
-	strbuf_reset(&buf);
-	if (fast_forward == FF_NO)
-		strbuf_addstr(&buf, "no-ff");
-	write_file_buf(git_path_merge_mode(the_repository), buf.buf, buf.len);
-	strbuf_release(&buf);
-}
-
-static void write_merge_state(struct commit_list *remoteheads)
-{
-	write_merge_heads(remoteheads);
-	strbuf_addch(&merge_msg, '\n');
-	write_file_buf(git_path_merge_msg(the_repository), merge_msg.buf,
-		       merge_msg.len);
-}
-
-static int default_edit_option(void)
-{
-	static const char name[] = "GIT_MERGE_AUTOEDIT";
-	const char *e = getenv(name);
-	struct stat st_stdin, st_stdout;
-
-	if (have_message)
-		/* an explicit -m msg without --[no-]edit */
-		return 0;
-
-	if (e) {
-		int v = git_parse_maybe_bool(e);
-		if (v < 0)
-			die(_("Bad value '%s' in environment '%s'"), e, name);
-		return v;
-	}
-
-	/* Use editor if stdin and stdout are the same and is a tty */
-	return (!fstat(0, &st_stdin) &&
-		!fstat(1, &st_stdout) &&
-		isatty(0) && isatty(1) &&
-		st_stdin.st_dev == st_stdout.st_dev &&
-		st_stdin.st_ino == st_stdout.st_ino &&
-		st_stdin.st_mode == st_stdout.st_mode);
-}
-
-static struct commit_list *reduce_parents(struct commit *head_commit,
-					  int *head_subsumed,
-					  struct commit_list *remoteheads)
-{
-	struct commit_list *parents, **remotes;
-
-	/*
-	 * Is the current HEAD reachable from another commit being
-	 * merged?  If so we do not want to record it as a parent of
-	 * the resulting merge, unless --no-ff is given.  We will flip
-	 * this variable to 0 when we find HEAD among the independent
-	 * tips being merged.
-	 */
-	*head_subsumed = 1;
-
-	/* Find what parents to record by checking independent ones. */
-	parents = reduce_heads(remoteheads);
-	free_commit_list(remoteheads);
-
-	remoteheads = NULL;
-	remotes = &remoteheads;
-	while (parents) {
-		struct commit *commit = pop_commit(&parents);
-		if (commit == head_commit)
-			*head_subsumed = 0;
-		else
-			remotes = &commit_list_insert(commit, remotes)->next;
-	}
-	return remoteheads;
-}
-
-static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
-{
-	struct fmt_merge_msg_opts opts;
-
-	memset(&opts, 0, sizeof(opts));
-	opts.add_title = !have_message;
-	opts.shortlog_len = shortlog_len;
-	opts.credit_people = (0 < option_edit);
-
-	fmt_merge_msg(merge_names, merge_msg, &opts);
-	if (merge_msg->len)
-		strbuf_setlen(merge_msg, merge_msg->len - 1);
-}
-
-static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
-{
-	const char *filename;
-	int fd, pos, npos;
-	struct strbuf fetch_head_file = STRBUF_INIT;
-	const unsigned hexsz = the_hash_algo->hexsz;
-
-	if (!merge_names)
-		merge_names = &fetch_head_file;
-
-	filename = git_path_fetch_head(the_repository);
-	fd = open(filename, O_RDONLY);
-	if (fd < 0)
-		die_errno(_("could not open '%s' for reading"), filename);
-
-	if (strbuf_read(merge_names, fd, 0) < 0)
-		die_errno(_("could not read '%s'"), filename);
-	if (close(fd) < 0)
-		die_errno(_("could not close '%s'"), filename);
-
-	for (pos = 0; pos < merge_names->len; pos = npos) {
-		struct object_id oid;
-		char *ptr;
-		struct commit *commit;
-
-		ptr = strchr(merge_names->buf + pos, '\n');
-		if (ptr)
-			npos = ptr - merge_names->buf + 1;
-		else
-			npos = merge_names->len;
-
-		if (npos - pos < hexsz + 2 ||
-		    get_oid_hex(merge_names->buf + pos, &oid))
-			commit = NULL; /* bad */
-		else if (memcmp(merge_names->buf + pos + hexsz, "\t\t", 2))
-			continue; /* not-for-merge */
-		else {
-			char saved = merge_names->buf[pos + hexsz];
-			merge_names->buf[pos + hexsz] = '\0';
-			commit = get_merge_parent(merge_names->buf + pos);
-			merge_names->buf[pos + hexsz] = saved;
-		}
-		if (!commit) {
-			if (ptr)
-				*ptr = '\0';
-			die(_("not something we can merge in %s: %s"),
-			    filename, merge_names->buf + pos);
-		}
-		remotes = &commit_list_insert(commit, remotes)->next;
-	}
-
-	if (merge_names == &fetch_head_file)
-		strbuf_release(&fetch_head_file);
-}
-
-static struct commit_list *collect_parents(struct commit *head_commit,
-					   int *head_subsumed,
-					   int argc, const char **argv,
-					   struct strbuf *merge_msg)
-{
-	int i;
-	struct commit_list *remoteheads = NULL;
-	struct commit_list **remotes = &remoteheads;
-	struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
-
-	if (merge_msg && (!have_message || shortlog_len))
-		autogen = &merge_names;
-
-	if (head_commit)
-		remotes = &commit_list_insert(head_commit, remotes)->next;
-
-	if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
-		handle_fetch_head(remotes, autogen);
-		remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
-	} else {
-		for (i = 0; i < argc; i++) {
-			struct commit *commit = get_merge_parent(argv[i]);
-			if (!commit)
-				help_unknown_ref(argv[i], "merge",
-						 _("not something we can merge"));
-			remotes = &commit_list_insert(commit, remotes)->next;
-		}
-		remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
-		if (autogen) {
-			struct commit_list *p;
-			for (p = remoteheads; p; p = p->next)
-				merge_name(merge_remote_util(p->item)->name, autogen);
-		}
-	}
-
-	if (autogen) {
-		prepare_merge_message(autogen, merge_msg);
-		strbuf_release(autogen);
-	}
-
-	return remoteheads;
-}
-
-static int merging_a_throwaway_tag(struct commit *commit)
-{
-	char *tag_ref;
-	struct object_id oid;
-	int is_throwaway_tag = 0;
-
-	/* Are we merging a tag? */
-	if (!merge_remote_util(commit) ||
-	    !merge_remote_util(commit)->obj ||
-	    merge_remote_util(commit)->obj->type != OBJ_TAG)
-		return is_throwaway_tag;
-
-	/*
-	 * Now we know we are merging a tag object.  Are we downstream
-	 * and following the tags from upstream?  If so, we must have
-	 * the tag object pointed at by "refs/tags/$T" where $T is the
-	 * tagname recorded in the tag object.  We want to allow such
-	 * a "just to catch up" merge to fast-forward.
-	 *
-	 * Otherwise, we are playing an integrator's role, making a
-	 * merge with a throw-away tag from a contributor with
-	 * something like "git pull $contributor $signed_tag".
-	 * We want to forbid such a merge from fast-forwarding
-	 * by default; otherwise we would not keep the signature
-	 * anywhere.
-	 */
-	tag_ref = xstrfmt("refs/tags/%s",
-			  ((struct tag *)merge_remote_util(commit)->obj)->tag);
-	if (!read_ref(tag_ref, &oid) &&
-	    oideq(&oid, &merge_remote_util(commit)->obj->oid))
-		is_throwaway_tag = 0;
-	else
-		is_throwaway_tag = 1;
-	free(tag_ref);
-	return is_throwaway_tag;
-}
-
-int cmd_merge(int argc, const char **argv, const char *prefix)
-{
-	struct object_id result_tree, stash, head_oid;
-	struct commit *head_commit;
-	struct strbuf buf = STRBUF_INIT;
-	int i, ret = 0, head_subsumed;
-	int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
-	struct commit_list *common = NULL;
-	const char *best_strategy = NULL, *wt_strategy = NULL;
-	struct commit_list *remoteheads, *p;
-	void *branch_to_free;
-	int orig_argc = argc;
-
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_merge_usage, builtin_merge_options);
-
-	/*
-	 * Check if we are _not_ on a detached HEAD, i.e. if there is a
-	 * current branch.
-	 */
-	branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
-	if (branch)
-		skip_prefix(branch, "refs/heads/", &branch);
-
-	init_diff_ui_defaults();
-	git_config(git_merge_config, NULL);
-
-	if (!branch || is_null_oid(&head_oid))
-		head_commit = NULL;
-	else
-		head_commit = lookup_commit_or_die(&head_oid, "HEAD");
-
-	if (branch_mergeoptions)
-		parse_branch_merge_options(branch_mergeoptions);
-	argc = parse_options(argc, argv, prefix, builtin_merge_options,
-			builtin_merge_usage, 0);
-	if (shortlog_len < 0)
-		shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
-
-	if (verbosity < 0 && show_progress == -1)
-		show_progress = 0;
-
-	if (abort_current_merge) {
-		int nargc = 2;
-		const char *nargv[] = {"reset", "--merge", NULL};
-		struct strbuf stash_oid = STRBUF_INIT;
-
-		if (orig_argc != 2)
-			usage_msg_opt(_("--abort expects no arguments"),
-			      builtin_merge_usage, builtin_merge_options);
-
-		if (!file_exists(git_path_merge_head(the_repository)))
-			die(_("There is no merge to abort (MERGE_HEAD missing)."));
-
-		if (read_oneliner(&stash_oid, git_path_merge_autostash(the_repository),
-		    READ_ONELINER_SKIP_IF_EMPTY))
-			unlink(git_path_merge_autostash(the_repository));
-
-		/* Invoke 'git reset --merge' */
-		ret = cmd_reset(nargc, nargv, prefix);
-
-		if (stash_oid.len)
-			apply_autostash_oid(stash_oid.buf);
-
-		strbuf_release(&stash_oid);
-		goto done;
-	}
-
-	if (quit_current_merge) {
-		if (orig_argc != 2)
-			usage_msg_opt(_("--quit expects no arguments"),
-				      builtin_merge_usage,
-				      builtin_merge_options);
-
-		remove_merge_branch_state(the_repository);
-		goto done;
-	}
-
-	if (continue_current_merge) {
-		int nargc = 1;
-		const char *nargv[] = {"commit", NULL};
-
-		if (orig_argc != 2)
-			usage_msg_opt(_("--continue expects no arguments"),
-			      builtin_merge_usage, builtin_merge_options);
-
-		if (!file_exists(git_path_merge_head(the_repository)))
-			die(_("There is no merge in progress (MERGE_HEAD missing)."));
-
-		/* Invoke 'git commit' */
-		ret = cmd_commit(nargc, nargv, prefix);
-		goto done;
-	}
-
-	if (read_cache_unmerged())
-		die_resolve_conflict("merge");
-
-	if (file_exists(git_path_merge_head(the_repository))) {
-		/*
-		 * There is no unmerged entry, don't advise 'git
-		 * add/rm <file>', just 'git commit'.
-		 */
-		if (advice_resolve_conflict)
-			die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
-				  "Please, commit your changes before you merge."));
-		else
-			die(_("You have not concluded your merge (MERGE_HEAD exists)."));
-	}
-	if (ref_exists("CHERRY_PICK_HEAD")) {
-		if (advice_resolve_conflict)
-			die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
-			    "Please, commit your changes before you merge."));
-		else
-			die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
-	}
-	resolve_undo_clear();
-
-	if (option_edit < 0)
-		option_edit = default_edit_option();
-
-	cleanup_mode = get_cleanup_mode(cleanup_arg, 0 < option_edit);
-
-	if (verbosity < 0)
-		show_diffstat = 0;
-
-	if (squash) {
-		if (fast_forward == FF_NO)
-			die(_("You cannot combine --squash with --no-ff."));
-		if (option_commit > 0)
-			die(_("You cannot combine --squash with --commit."));
-		/*
-		 * squash can now silently disable option_commit - this is not
-		 * a problem as it is only overriding the default, not a user
-		 * supplied option.
-		 */
-		option_commit = 0;
-	}
-
-	if (option_commit < 0)
-		option_commit = 1;
-
-	if (!argc) {
-		if (default_to_upstream)
-			argc = setup_with_upstream(&argv);
-		else
-			die(_("No commit specified and merge.defaultToUpstream not set."));
-	} else if (argc == 1 && !strcmp(argv[0], "-")) {
-		argv[0] = "@{-1}";
-	}
-
-	if (!argc)
-		usage_with_options(builtin_merge_usage,
-			builtin_merge_options);
-
-	if (!head_commit) {
-		/*
-		 * If the merged head is a valid one there is no reason
-		 * to forbid "git merge" into a branch yet to be born.
-		 * We do the same for "git pull".
-		 */
-		struct object_id *remote_head_oid;
-		if (squash)
-			die(_("Squash commit into empty head not supported yet"));
-		if (fast_forward == FF_NO)
-			die(_("Non-fast-forward commit does not make sense into "
-			    "an empty head"));
-		remoteheads = collect_parents(head_commit, &head_subsumed,
-					      argc, argv, NULL);
-		if (!remoteheads)
-			die(_("%s - not something we can merge"), argv[0]);
-		if (remoteheads->next)
-			die(_("Can merge only exactly one commit into empty head"));
-
-		if (verify_signatures)
-			verify_merge_signature(remoteheads->item, verbosity,
-					       check_trust_level);
-
-		remote_head_oid = &remoteheads->item->object.oid;
-		read_empty(remote_head_oid, 0);
-		update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
-			   UPDATE_REFS_DIE_ON_ERR);
-		goto done;
-	}
-
-	/*
-	 * All the rest are the commits being merged; prepare
-	 * the standard merge summary message to be appended
-	 * to the given message.
-	 */
-	remoteheads = collect_parents(head_commit, &head_subsumed,
-				      argc, argv, &merge_msg);
-
-	if (!head_commit || !argc)
-		usage_with_options(builtin_merge_usage,
-			builtin_merge_options);
-
-	if (verify_signatures) {
-		for (p = remoteheads; p; p = p->next) {
-			verify_merge_signature(p->item, verbosity,
-					       check_trust_level);
-		}
-	}
-
-	strbuf_addstr(&buf, "merge");
-	for (p = remoteheads; p; p = p->next)
-		strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
-	setenv("GIT_REFLOG_ACTION", buf.buf, 0);
-	strbuf_reset(&buf);
-
-	for (p = remoteheads; p; p = p->next) {
-		struct commit *commit = p->item;
-		strbuf_addf(&buf, "GITHEAD_%s",
-			    oid_to_hex(&commit->object.oid));
-		setenv(buf.buf, merge_remote_util(commit)->name, 1);
-		strbuf_reset(&buf);
-		if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
-			fast_forward = FF_NO;
-	}
-
-	if (!use_strategies) {
-		if (!remoteheads)
-			; /* already up-to-date */
-		else if (!remoteheads->next)
-			add_strategies(pull_twohead, DEFAULT_TWOHEAD);
-		else
-			add_strategies(pull_octopus, DEFAULT_OCTOPUS);
-	}
-
-	for (i = 0; i < use_strategies_nr; i++) {
-		if (use_strategies[i]->attr & NO_FAST_FORWARD)
-			fast_forward = FF_NO;
-		if (use_strategies[i]->attr & NO_TRIVIAL)
-			allow_trivial = 0;
-	}
-
-	if (!remoteheads)
-		; /* already up-to-date */
-	else if (!remoteheads->next)
-		common = get_merge_bases(head_commit, remoteheads->item);
-	else {
-		struct commit_list *list = remoteheads;
-		commit_list_insert(head_commit, &list);
-		common = get_octopus_merge_bases(list);
-		free(list);
-	}
-
-	update_ref("updating ORIG_HEAD", "ORIG_HEAD",
-		   &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
-
-	if (remoteheads && !common) {
-		/* No common ancestors found. */
-		if (!allow_unrelated_histories)
-			die(_("refusing to merge unrelated histories"));
-		/* otherwise, we need a real merge. */
-	} else if (!remoteheads ||
-		 (!remoteheads->next && !common->next &&
-		  common->item == remoteheads->item)) {
-		/*
-		 * If head can reach all the merge then we are up to date.
-		 * but first the most common case of merging one remote.
-		 */
-		finish_up_to_date(_("Already up to date."));
-		goto done;
-	} else if (fast_forward != FF_NO && !remoteheads->next &&
-			!common->next &&
-			oideq(&common->item->object.oid, &head_commit->object.oid)) {
-		/* Again the most common case of merging one remote. */
-		struct strbuf msg = STRBUF_INIT;
-		struct commit *commit;
-
-		if (verbosity >= 0) {
-			printf(_("Updating %s..%s\n"),
-			       find_unique_abbrev(&head_commit->object.oid,
-						  DEFAULT_ABBREV),
-			       find_unique_abbrev(&remoteheads->item->object.oid,
-						  DEFAULT_ABBREV));
-		}
-		strbuf_addstr(&msg, "Fast-forward");
-		if (have_message)
-			strbuf_addstr(&msg,
-				" (no commit created; -m option ignored)");
-		commit = remoteheads->item;
-		if (!commit) {
-			ret = 1;
-			goto done;
-		}
-
-		if (autostash)
-			create_autostash(the_repository,
-					 git_path_merge_autostash(the_repository),
-					 "merge");
-		if (checkout_fast_forward(the_repository,
-					  &head_commit->object.oid,
-					  &commit->object.oid,
-					  overwrite_ignore)) {
-			ret = 1;
-			goto done;
-		}
-
-		finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
-		remove_merge_branch_state(the_repository);
-		goto done;
-	} else if (!remoteheads->next && common->next)
-		;
-		/*
-		 * We are not doing octopus and not fast-forward.  Need
-		 * a real merge.
-		 */
-	else if (!remoteheads->next && !common->next && option_commit) {
-		/*
-		 * We are not doing octopus, not fast-forward, and have
-		 * only one common.
-		 */
-		refresh_cache(REFRESH_QUIET);
-		if (allow_trivial && fast_forward != FF_ONLY) {
-			/* See if it is really trivial. */
-			git_committer_info(IDENT_STRICT);
-			printf(_("Trying really trivial in-index merge...\n"));
-			if (!read_tree_trivial(&common->item->object.oid,
-					       &head_commit->object.oid,
-					       &remoteheads->item->object.oid)) {
-				ret = merge_trivial(head_commit, remoteheads);
-				goto done;
-			}
-			printf(_("Nope.\n"));
-		}
-	} else {
-		/*
-		 * An octopus.  If we can reach all the remote we are up
-		 * to date.
-		 */
-		int up_to_date = 1;
-		struct commit_list *j;
-
-		for (j = remoteheads; j; j = j->next) {
-			struct commit_list *common_one;
-
-			/*
-			 * Here we *have* to calculate the individual
-			 * merge_bases again, otherwise "git merge HEAD^
-			 * HEAD^^" would be missed.
-			 */
-			common_one = get_merge_bases(head_commit, j->item);
-			if (!oideq(&common_one->item->object.oid, &j->item->object.oid)) {
-				up_to_date = 0;
-				break;
-			}
-		}
-		if (up_to_date) {
-			finish_up_to_date(_("Already up to date. Yeeah!"));
-			goto done;
-		}
-	}
-
-	if (fast_forward == FF_ONLY)
-		die(_("Not possible to fast-forward, aborting."));
-
-	if (autostash)
-		create_autostash(the_repository,
-				 git_path_merge_autostash(the_repository),
-				 "merge");
-
-	/* We are going to make a new commit. */
-	git_committer_info(IDENT_STRICT);
-
-	/*
-	 * At this point, we need a real merge.  No matter what strategy
-	 * we use, it would operate on the index, possibly affecting the
-	 * working tree, and when resolved cleanly, have the desired
-	 * tree in the index -- this means that the index must be in
-	 * sync with the head commit.  The strategies are responsible
-	 * to ensure this.
-	 */
-	if (use_strategies_nr == 1 ||
-	    /*
-	     * Stash away the local changes so that we can try more than one.
-	     */
-	    save_state(&stash))
-		oidclr(&stash);
-
-	for (i = 0; !merge_was_ok && i < use_strategies_nr; i++) {
-		int ret, cnt;
-		if (i) {
-			printf(_("Rewinding the tree to pristine...\n"));
-			restore_state(&head_commit->object.oid, &stash);
-		}
-		if (use_strategies_nr != 1)
-			printf(_("Trying merge strategy %s...\n"),
-				use_strategies[i]->name);
-		/*
-		 * Remember which strategy left the state in the working
-		 * tree.
-		 */
-		wt_strategy = use_strategies[i]->name;
-
-		ret = try_merge_strategy(use_strategies[i]->name,
-					 common, remoteheads,
-					 head_commit);
-		/*
-		 * The backend exits with 1 when conflicts are
-		 * left to be resolved, with 2 when it does not
-		 * handle the given merge at all.
-		 */
-		if (ret < 2) {
-			if (!ret) {
-				if (option_commit) {
-					/* Automerge succeeded. */
-					automerge_was_ok = 1;
-					break;
-				}
-				merge_was_ok = 1;
-			}
-			cnt = (use_strategies_nr > 1) ? evaluate_result() : 0;
-			if (best_cnt <= 0 || cnt <= best_cnt) {
-				best_strategy = use_strategies[i]->name;
-				best_cnt = cnt;
-			}
-		}
-	}
-
-	/*
-	 * If we have a resulting tree, that means the strategy module
-	 * auto resolved the merge cleanly.
-	 */
-	if (automerge_was_ok) {
-		ret = finish_automerge(head_commit, head_subsumed,
-				       common, remoteheads,
-				       &result_tree, wt_strategy);
-		goto done;
-	}
-
-	/*
-	 * Pick the result from the best strategy and have the user fix
-	 * it up.
-	 */
-	if (!best_strategy) {
-		restore_state(&head_commit->object.oid, &stash);
-		if (use_strategies_nr > 1)
-			fprintf(stderr,
-				_("No merge strategy handled the merge.\n"));
-		else
-			fprintf(stderr, _("Merge with strategy %s failed.\n"),
-				use_strategies[0]->name);
-		ret = 2;
-		goto done;
-	} else if (best_strategy == wt_strategy)
-		; /* We already have its result in the working tree. */
-	else {
-		printf(_("Rewinding the tree to pristine...\n"));
-		restore_state(&head_commit->object.oid, &stash);
-		printf(_("Using the %s to prepare resolving by hand.\n"),
-			best_strategy);
-		try_merge_strategy(best_strategy, common, remoteheads,
-				   head_commit);
-	}
-
-	if (squash) {
-		finish(head_commit, remoteheads, NULL, NULL);
-
-		git_test_write_commit_graph_or_die();
-	} else
-		write_merge_state(remoteheads);
-
-	if (merge_was_ok)
-		fprintf(stderr, _("Automatic merge went well; "
-			"stopped before committing as requested\n"));
-	else
-		ret = suggest_conflicts();
-
-done:
-	free(branch_to_free);
-	return ret;
-}