static int reset_refs(const char *rev, const unsigned char *sha1)
{
	int update_ref_status;
	struct strbuf msg = STRBUF_INIT;
	struct strbuf err = STRBUF_INIT;
	unsigned char *orig = NULL, sha1_orig[20],
		*old_orig = NULL, sha1_old_orig[20];

	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
		old_orig = sha1_old_orig;
	if (!get_sha1("HEAD", sha1_orig)) {
		orig = sha1_orig;
		set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
		if (update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, &err))
			error("%s", err.buf);
		strbuf_release(&err);
	} else if (old_orig)
		delete_ref("ORIG_HEAD", old_orig, 0);
	set_reflog_message(&msg, "updating HEAD", rev);
	update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, &err);
	if (update_ref_status)
		error("%s", err.buf);
	strbuf_release(&err);
	strbuf_release(&msg);
	return update_ref_status;
}

static int delete_replace_ref(const char *name, const char *ref,
			      const struct object_id *oid)
{
	if (delete_ref(NULL, ref, oid, 0))
		return 1;
	printf("Deleted replace ref '%s'\n", name);
	return 0;
}

static int do_clear_stash(void)
{
	struct object_id obj;
	if (get_oid(ref_stash, &obj))
		return 0;

	return delete_ref(NULL, ref_stash, &obj, 0);
}

static int merge_abort(struct notes_merge_options *o)
{
	int ret = 0;

	/*
	 * Remove .git/NOTES_MERGE_PARTIAL and .git/NOTES_MERGE_REF, and call
	 * notes_merge_abort() to remove .git/NOTES_MERGE_WORKTREE.
	 */

	if (delete_ref("NOTES_MERGE_PARTIAL", NULL, 0))
		ret += error("Failed to delete ref NOTES_MERGE_PARTIAL");
	if (delete_ref("NOTES_MERGE_REF", NULL, REF_NODEREF))
		ret += error("Failed to delete ref NOTES_MERGE_REF");
	if (notes_merge_abort(o))
		ret += error("Failed to remove 'git notes merge' worktree");
	return ret;
}

static int delete_tag(const char *name, const char *ref,
				const unsigned char *sha1)
{
	if (delete_ref(ref, sha1, 0))
		return 1;
	printf(_("Deleted tag '%s' (was %s)\n"), name, find_unique_abbrev(sha1, DEFAULT_ABBREV));
	return 0;
}

static void update_tracking_ref(struct remote *remote, struct ref *ref)
{
	struct refspec rs;

	if (ref->status != REF_STATUS_OK && ref->status != REF_STATUS_UPTODATE)
		return;

	rs.src = ref->name;
	rs.dst = NULL;

	if (!remote_find_tracking(remote, &rs)) {
		if (args.verbose)
			fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
		if (ref->deletion) {
			delete_ref(rs.dst, NULL, 0);
		} else
			update_ref("update by push", rs.dst,
					ref->new_sha1, NULL, 0, 0);
		free(rs.dst);
	}
}

static int prune_refs(struct transport *transport, struct ref *ref_map)
{
	int result = 0;
	struct ref *ref, *stale_refs = get_stale_heads(transport->remote, ref_map);
	const char *dangling_msg = dry_run
		? "   (%s will become dangling)\n"
		: "   (%s has become dangling)\n";

	for (ref = stale_refs; ref; ref = ref->next) {
		if (!dry_run)
			result |= delete_ref(ref->name, NULL, 0);
		if (verbosity >= 0) {
			fprintf(stderr, " x %-*s %-*s -> %s\n",
				TRANSPORT_SUMMARY_WIDTH, "[deleted]",
				REFCOL_WIDTH, "(none)", prettify_refname(ref->name));
			warn_dangling_symref(stderr, dangling_msg, ref->name);
		}
	}
	free_refs(stale_refs);
	return result;
}

static int reset_refs(const char *rev, const struct object_id *oid)
{
	int update_ref_status;
	struct strbuf msg = STRBUF_INIT;
	struct object_id *orig = NULL, oid_orig,
		*old_orig = NULL, oid_old_orig;

	if (!get_oid("ORIG_HEAD", &oid_old_orig))
		old_orig = &oid_old_orig;
	if (!get_oid("HEAD", &oid_orig)) {
		orig = &oid_orig;
		set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
		update_ref_oid(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
			   UPDATE_REFS_MSG_ON_ERR);
	} else if (old_orig)
		delete_ref("ORIG_HEAD", old_orig->hash, 0);
	set_reflog_message(&msg, "updating HEAD", rev);
	update_ref_status = update_ref_oid(msg.buf, "HEAD", oid, orig, 0,
				       UPDATE_REFS_MSG_ON_ERR);
	strbuf_release(&msg);
	return update_ref_status;
}

//.........这里部分代码省略.........
		switch (deny_current_branch) {
		case DENY_IGNORE:
			break;
		case DENY_WARN:
			rp_warning("updating the current branch");
			break;
		case DENY_REFUSE:
		case DENY_UNCONFIGURED:
			rp_error("refusing to update checked out branch: %s", name);
			if (deny_current_branch == DENY_UNCONFIGURED)
				refuse_unconfigured_deny();
			return "branch is currently checked out";
		}
	}

	if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
		error("unpack should have generated %s, "
		      "but I can't find it!", sha1_to_hex(new_sha1));
		return "bad pack";
	}

	if (!is_null_sha1(old_sha1) && is_null_sha1(new_sha1)) {
		if (deny_deletes && !prefixcmp(name, "refs/heads/")) {
			rp_error("denying ref deletion for %s", name);
			return "deletion prohibited";
		}

		if (!strcmp(namespaced_name, head_name)) {
			switch (deny_delete_current) {
			case DENY_IGNORE:
				break;
			case DENY_WARN:
				rp_warning("deleting the current branch");
				break;
			case DENY_REFUSE:
			case DENY_UNCONFIGURED:
				if (deny_delete_current == DENY_UNCONFIGURED)
					refuse_unconfigured_deny_delete_current();
				rp_error("refusing to delete the current branch: %s", name);
				return "deletion of the current branch prohibited";
			}
		}
	}

	if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
	    !is_null_sha1(old_sha1) &&
	    !prefixcmp(name, "refs/heads/")) {
		struct object *old_object, *new_object;
		struct commit *old_commit, *new_commit;

		old_object = parse_object(old_sha1);
		new_object = parse_object(new_sha1);

		if (!old_object || !new_object ||
		    old_object->type != OBJ_COMMIT ||
		    new_object->type != OBJ_COMMIT) {
			error("bad sha1 objects for %s", name);
			return "bad ref";
		}
		old_commit = (struct commit *)old_object;
		new_commit = (struct commit *)new_object;
		if (!in_merge_bases(old_commit, new_commit)) {
			rp_error("denying non-fast-forward %s"
				 " (you should pull first)", name);
			return "non-fast-forward";
		}
	}
	if (run_update_hook(cmd)) {
		rp_error("hook declined to update %s", name);
		return "hook declined";
	}

	if (is_null_sha1(new_sha1)) {
		if (!parse_object(old_sha1)) {
			old_sha1 = NULL;
			if (ref_exists(name)) {
				rp_warning("Allowing deletion of corrupt ref.");
			} else {
				rp_warning("Deleting a non-existent ref.");
				cmd->did_not_exist = 1;
			}
		}
		if (delete_ref(namespaced_name, old_sha1, 0)) {
			rp_error("failed to delete %s", name);
			return "failed to delete";
		}
		return NULL; /* good */
	}
	else {
		lock = lock_any_ref_for_update(namespaced_name, old_sha1, 0);
		if (!lock) {
			rp_error("failed to lock %s", name);
			return "failed to lock";
		}
		if (write_ref_sha1(lock, new_sha1, "push")) {
			return "failed to write"; /* error() already called */
		}
		return NULL; /* good */
	}
}

static const char *update(struct command *cmd)
{
	const char *name = cmd->ref_name;
	unsigned char *old_sha1 = cmd->old_sha1;
	unsigned char *new_sha1 = cmd->new_sha1;
	struct ref_lock *lock;

	/* only refs/... are allowed */
	if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
		error("refusing to create funny ref '%s' remotely", name);
		return "funny refname";
	}

	if (is_ref_checked_out(name)) {
		switch (deny_current_branch) {
		case DENY_IGNORE:
			break;
		case DENY_UNCONFIGURED:
		case DENY_WARN:
			warning("updating the current branch");
			if (deny_current_branch == DENY_UNCONFIGURED)
				warn_unconfigured_deny();
			break;
		case DENY_REFUSE:
			error("refusing to update checked out branch: %s", name);
			return "branch is currently checked out";
		}
	}

	if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
		error("unpack should have generated %s, "
		      "but I can't find it!", sha1_to_hex(new_sha1));
		return "bad pack";
	}

	if (!is_null_sha1(old_sha1) && is_null_sha1(new_sha1)) {
		if (deny_deletes && !prefixcmp(name, "refs/heads/")) {
			error("denying ref deletion for %s", name);
			return "deletion prohibited";
		}

		if (!strcmp(name, head_name)) {
			switch (deny_delete_current) {
			case DENY_IGNORE:
				break;
			case DENY_WARN:
			case DENY_UNCONFIGURED:
				if (deny_delete_current == DENY_UNCONFIGURED)
					warn_unconfigured_deny_delete_current();
				warning("deleting the current branch");
				break;
			case DENY_REFUSE:
				error("refusing to delete the current branch: %s", name);
				return "deletion of the current branch prohibited";
			}
		}
	}

	if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
	    !is_null_sha1(old_sha1) &&
	    !prefixcmp(name, "refs/heads/")) {
		struct object *old_object, *new_object;
		struct commit *old_commit, *new_commit;
		struct commit_list *bases, *ent;

		old_object = parse_object(old_sha1);
		new_object = parse_object(new_sha1);

		if (!old_object || !new_object ||
		    old_object->type != OBJ_COMMIT ||
		    new_object->type != OBJ_COMMIT) {
			error("bad sha1 objects for %s", name);
			return "bad ref";
		}
		old_commit = (struct commit *)old_object;
		new_commit = (struct commit *)new_object;
		bases = get_merge_bases(old_commit, new_commit, 1);
		for (ent = bases; ent; ent = ent->next)
			if (!hashcmp(old_sha1, ent->item->object.sha1))
				break;
		free_commit_list(bases);
		if (!ent) {
			error("denying non-fast forward %s"
			      " (you should pull first)", name);
			return "non-fast forward";
		}
	}
	if (run_update_hook(cmd)) {
		error("hook declined to update %s", name);
		return "hook declined";
	}

	if (is_null_sha1(new_sha1)) {
		if (!parse_object(old_sha1)) {
			warning ("Allowing deletion of corrupt ref.");
			old_sha1 = NULL;
		}
		if (delete_ref(name, old_sha1, 0)) {
			error("failed to delete %s", name);
			return "failed to delete";
//.........这里部分代码省略.........

//.........这里部分代码省略.........
	 * git reset [-opts] <rev> -- <paths>...
	 * git reset [-opts] -- <paths>...
	 * git reset [-opts] <paths>...
	 *
	 * At this point, argv[i] points immediately after [-opts].
	 */

	if (i < argc) {
		if (!strcmp(argv[i], "--")) {
			i++; /* reset to HEAD, possibly with paths */
		} else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
			rev = argv[i];
			i += 2;
		}
		/*
		 * Otherwise, argv[i] could be either <rev> or <paths> and
		 * has to be unambigous.
		 */
		else if (!get_sha1(argv[i], sha1)) {
			/*
			 * Ok, argv[i] looks like a rev; it should not
			 * be a filename.
			 */
			verify_non_filename(prefix, argv[i]);
			rev = argv[i++];
		} else {
			/* Otherwise we treat this as a filename */
			verify_filename(prefix, argv[i]);
		}
	}

	if (get_sha1(rev, sha1))
		die("Failed to resolve '%s' as a valid ref.", rev);

	commit = lookup_commit_reference(sha1);
	if (!commit)
		die("Could not parse object '%s'.", rev);
	hashcpy(sha1, commit->object.sha1);

	/* git reset tree [--] paths... can be used to
	 * load chosen paths from the tree into the index without
	 * affecting the working tree nor HEAD. */
	if (i < argc) {
		if (reset_type == MIXED)
			warning("--mixed option is deprecated with paths.");
		else if (reset_type != NONE)
			die("Cannot do %s reset with paths.",
					reset_type_names[reset_type]);
		return read_from_tree(prefix, argv + i, sha1,
				quiet ? REFRESH_QUIET : REFRESH_SAY_CHANGED);
	}
	if (reset_type == NONE)
		reset_type = MIXED; /* by default */

	if (reset_type == HARD && is_bare_repository())
		die("hard reset makes no sense in a bare repository");

	/* Soft reset does not touch the index file nor the working tree
	 * at all, but requires them in a good order.  Other resets reset
	 * the index file to the tree object we are switching to. */
	if (reset_type == SOFT) {
		if (is_merge() || read_cache() < 0 || unmerged_cache())
			die("Cannot do a soft reset in the middle of a merge.");
	}
	else if (reset_index_file(sha1, (reset_type == HARD), quiet))
		die("Could not reset index file to revision '%s'.", rev);

	/* Any resets update HEAD to the head being switched to,
	 * saving the previous head in ORIG_HEAD before. */
	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
		old_orig = sha1_old_orig;
	if (!get_sha1("HEAD", sha1_orig)) {
		orig = sha1_orig;
		prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
		update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	}
	else if (old_orig)
		delete_ref("ORIG_HEAD", old_orig);
	prepend_reflog_action("updating HEAD", msg, sizeof(msg));
	update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);

	switch (reset_type) {
	case HARD:
		if (!update_ref_status && !quiet)
			print_new_head_line(commit);
		break;
	case SOFT: /* Nothing else to do. */
		break;
	case MIXED: /* Report what has not been updated. */
		update_index_refresh(0, NULL,
				quiet ? REFRESH_QUIET : REFRESH_SAY_CHANGED);
		break;
	}

	remove_branch_state();

	free(reflog_action);

	return update_ref_status;
}

int rename_ref(const char *oldref, const char *newref, const char *logmsg)
{
	static const char renamed_ref[] = "RENAMED-REF";
	unsigned char sha1[20], orig_sha1[20];
	int flag = 0, logmoved = 0;
	struct ref_lock *lock;
	struct stat loginfo;
	int log = !lstat(git_path("logs/%s", oldref), &loginfo);
	const char *symref = NULL;

	if (log && S_ISLNK(loginfo.st_mode))
		return error("reflog for %s is a symlink", oldref);

	symref = resolve_ref(oldref, orig_sha1, 1, &flag);
	if (flag & REF_ISSYMREF)
		return error("refname %s is a symbolic ref, renaming it is not supported",
			oldref);
	if (!symref)
		return error("refname %s not found", oldref);

	if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
		return 1;

	if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
		return 1;

	lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
	if (!lock)
		return error("unable to lock %s", renamed_ref);
	lock->force_write = 1;
	if (write_ref_sha1(lock, orig_sha1, logmsg))
		return error("unable to save current sha1 in %s", renamed_ref);

	if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
		return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
			oldref, strerror(errno));

	if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
		error("unable to delete old %s", oldref);
		goto rollback;
	}

	if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
		if (errno==EISDIR) {
			if (remove_empty_directories(git_path("%s", newref))) {
				error("Directory not empty: %s", newref);
				goto rollback;
			}
		} else {
			error("unable to delete existing %s", newref);
			goto rollback;
		}
	}

	if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
		error("unable to create directory for %s", newref);
		goto rollback;
	}

 retry:
	if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
		if (errno==EISDIR || errno==ENOTDIR) {
			/*
			 * rename(a, b) when b is an existing
			 * directory ought to result in ISDIR, but
			 * Solaris 5.8 gives ENOTDIR.  Sheesh.
			 */
			if (remove_empty_directories(git_path("logs/%s", newref))) {
				error("Directory not empty: logs/%s", newref);
				goto rollback;
			}
			goto retry;
		} else {
			error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
				newref, strerror(errno));
			goto rollback;
		}
	}
	logmoved = log;

	lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
	if (!lock) {
		error("unable to lock %s for update", newref);
		goto rollback;
	}
	lock->force_write = 1;
	hashcpy(lock->old_sha1, orig_sha1);
	if (write_ref_sha1(lock, orig_sha1, logmsg)) {
		error("unable to write current sha1 into %s", newref);
		goto rollback;
	}

	return 0;

 rollback:
	lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
	if (!lock) {
		error("unable to lock %s for rollback", oldref);
		goto rollbacklog;
	}
//.........这里部分代码省略.........

static int delete_branches(int argc, const char **argv, int force, int kinds)
{
	struct commit *rev, *head_rev = NULL;
	unsigned char sha1[20];
	char *name = NULL;
	const char *fmt, *remote;
	int i;
	int ret = 0;
	struct strbuf bname = STRBUF_INIT;

	switch (kinds) {
	case REF_REMOTE_BRANCH:
		fmt = "refs/remotes/%s";
		/* TRANSLATORS: This is "remote " in "remote branch '%s' not found" */
		remote = _("remote ");
		force = 1;
		break;
	case REF_LOCAL_BRANCH:
		fmt = "refs/heads/%s";
		remote = "";
		break;
	default:
		die(_("cannot use -a with -d"));
	}

	if (!force) {
		head_rev = lookup_commit_reference(head_sha1);
		if (!head_rev)
			die(_("Couldn't look up commit object for HEAD"));
	}
	for (i = 0; i < argc; i++, strbuf_release(&bname)) {
		strbuf_branchname(&bname, argv[i]);
		if (kinds == REF_LOCAL_BRANCH && !strcmp(head, bname.buf)) {
			error(_("Cannot delete the branch '%s' "
			      "which you are currently on."), bname.buf);
			ret = 1;
			continue;
		}

		free(name);

		name = xstrdup(mkpath(fmt, bname.buf));
		if (!resolve_ref(name, sha1, 1, NULL)) {
			error(_("%sbranch '%s' not found."),
					remote, bname.buf);
			ret = 1;
			continue;
		}

		rev = lookup_commit_reference(sha1);
		if (!rev) {
			error(_("Couldn't look up commit object for '%s'"), name);
			ret = 1;
			continue;
		}

		if (!force && !branch_merged(kinds, bname.buf, rev, head_rev)) {
			error(_("The branch '%s' is not fully merged.\n"
			      "If you are sure you want to delete it, "
			      "run 'git branch -D %s'."), bname.buf, bname.buf);
			ret = 1;
			continue;
		}

		if (delete_ref(name, sha1, 0)) {
			error(_("Error deleting %sbranch '%s'"), remote,
			      bname.buf);
			ret = 1;
		} else {
			struct strbuf buf = STRBUF_INIT;
			printf(_("Deleted %sbranch %s (was %s).\n"), remote,
			       bname.buf,
			       find_unique_abbrev(sha1, DEFAULT_ABBREV));
			strbuf_addf(&buf, "branch.%s", bname.buf);
			if (git_config_rename_section(buf.buf, NULL) < 0)
				warning(_("Update of config-file failed"));
			strbuf_release(&buf);
		}
	}

	free(name);

	return(ret);
}

static int delete_branches(int argc, const char **argv, int force, int kinds)
{
	struct commit *rev, *head_rev = head_rev;
	unsigned char sha1[20];
	char *name = NULL;
	const char *fmt, *remote;
	int i;
	int ret = 0;
	struct strbuf bname = STRBUF_INIT;

	switch (kinds) {
	case REF_REMOTE_BRANCH:
		fmt = "refs/remotes/%s";
		remote = "remote ";
		force = 1;
		break;
	case REF_LOCAL_BRANCH:
		fmt = "refs/heads/%s";
		remote = "";
		break;
	default:
		die("cannot use -a with -d");
	}

	if (!force) {
		head_rev = lookup_commit_reference(head_sha1);
		if (!head_rev)
			die("Couldn't look up commit object for HEAD");
	}
	for (i = 0; i < argc; i++, strbuf_release(&bname)) {
		int len = strlen(argv[i]);

		if (interpret_nth_last_branch(argv[i], &bname) != len)
			strbuf_add(&bname, argv[i], len);

		if (kinds == REF_LOCAL_BRANCH && !strcmp(head, bname.buf)) {
			error("Cannot delete the branch '%s' "
			      "which you are currently on.", bname.buf);
			ret = 1;
			continue;
		}

		free(name);

		name = xstrdup(mkpath(fmt, bname.buf));
		if (!resolve_ref(name, sha1, 1, NULL)) {
			error("%sbranch '%s' not found.",
					remote, bname.buf);
			ret = 1;
			continue;
		}

		rev = lookup_commit_reference(sha1);
		if (!rev) {
			error("Couldn't look up commit object for '%s'", name);
			ret = 1;
			continue;
		}

		/* This checks whether the merge bases of branch and
		 * HEAD contains branch -- which means that the HEAD
		 * contains everything in both.
		 */

		if (!force &&
		    !in_merge_bases(rev, &head_rev, 1)) {
			error("The branch '%s' is not an ancestor of "
			      "your current HEAD.\n"
			      "If you are sure you want to delete it, "
			      "run 'git branch -D %s'.", bname.buf, bname.buf);
			ret = 1;
			continue;
		}

		if (delete_ref(name, sha1, 0)) {
			error("Error deleting %sbranch '%s'", remote,
			      bname.buf);
			ret = 1;
		} else {
			struct strbuf buf = STRBUF_INIT;
			printf("Deleted %sbranch %s (%s).\n", remote,
			       bname.buf,
			       find_unique_abbrev(sha1, DEFAULT_ABBREV));
			strbuf_addf(&buf, "branch.%s", bname.buf);
			if (git_config_rename_section(buf.buf, NULL) < 0)
				warning("Update of config-file failed");
			strbuf_release(&buf);
		}
	}

	free(name);

	return(ret);
}

static int delete_branches(int argc, const char **argv, int force, int kinds,
			   int quiet)
{
	struct commit *head_rev = NULL;
	unsigned char sha1[20];
	char *name = NULL;
	const char *fmt;
	int i;
	int ret = 0;
	int remote_branch = 0;
	struct strbuf bname = STRBUF_INIT;

	switch (kinds) {
	case REF_REMOTE_BRANCH:
		fmt = "refs/remotes/%s";
		/* For subsequent UI messages */
		remote_branch = 1;

		force = 1;
		break;
	case REF_LOCAL_BRANCH:
		fmt = "refs/heads/%s";
		break;
	default:
		die(_("cannot use -a with -d"));
	}

	if (!force) {
		head_rev = lookup_commit_reference(head_sha1);
		if (!head_rev)
			die(_("Couldn't look up commit object for HEAD"));
	}
	for (i = 0; i < argc; i++, strbuf_release(&bname)) {
		const char *target;
		int flags = 0;

		strbuf_branchname(&bname, argv[i]);
		if (kinds == REF_LOCAL_BRANCH && !strcmp(head, bname.buf)) {
			error(_("Cannot delete the branch '%s' "
			      "which you are currently on."), bname.buf);
			ret = 1;
			continue;
		}

		free(name);

		name = mkpathdup(fmt, bname.buf);
		target = resolve_ref_unsafe(name, sha1, 0, &flags);
		if (!target ||
		    (!(flags & REF_ISSYMREF) && is_null_sha1(sha1))) {
			error(remote_branch
			      ? _("remote branch '%s' not found.")
			      : _("branch '%s' not found."), bname.buf);
			ret = 1;
			continue;
		}

		if (!(flags & REF_ISSYMREF) &&
		    check_branch_commit(bname.buf, name, sha1, head_rev, kinds,
					force)) {
			ret = 1;
			continue;
		}

		if (delete_ref(name, sha1, REF_NODEREF)) {
			error(remote_branch
			      ? _("Error deleting remote branch '%s'")
			      : _("Error deleting branch '%s'"),
			      bname.buf);
			ret = 1;
			continue;
		}
		if (!quiet) {
			printf(remote_branch
			       ? _("Deleted remote branch %s (was %s).\n")
			       : _("Deleted branch %s (was %s).\n"),
			       bname.buf,
			       (flags & REF_ISSYMREF)
			       ? target
			       : find_unique_abbrev(sha1, DEFAULT_ABBREV));
		}
		delete_branch_config(bname.buf);
	}

	free(name);

	return(ret);
}

//.........这里部分代码省略.........
		 * has to be unambiguous.
		 */
		else if (!get_sha1(argv[i], sha1)) {
			/*
			 * Ok, argv[i] looks like a rev; it should not
			 * be a filename.
			 */
			verify_non_filename(prefix, argv[i]);
			rev = argv[i++];
		} else {
			/* Otherwise we treat this as a filename */
			verify_filename(prefix, argv[i]);
		}
	}

	if (get_sha1(rev, sha1))
		die(_("Failed to resolve '%s' as a valid ref."), rev);

	commit = lookup_commit_reference(sha1);
	if (!commit)
		die(_("Could not parse object '%s'."), rev);
	hashcpy(sha1, commit->object.sha1);

	if (patch_mode) {
		if (reset_type != NONE)
			die(_("--patch is incompatible with --{hard,mixed,soft}"));
		return interactive_reset(rev, argv + i, prefix);
	}

	/* git reset tree [--] paths... can be used to
	 * load chosen paths from the tree into the index without
	 * affecting the working tree nor HEAD. */
	if (i < argc) {
		if (reset_type == MIXED)
			warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
		else if (reset_type != NONE)
			die(_("Cannot do %s reset with paths."),
					_(reset_type_names[reset_type]));
		return read_from_tree(prefix, argv + i, sha1,
				quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
	}
	if (reset_type == NONE)
		reset_type = MIXED; /* by default */

	if (reset_type != SOFT && reset_type != MIXED)
		setup_work_tree();

	if (reset_type == MIXED && is_bare_repository())
		die(_("%s reset is not allowed in a bare repository"),
		    _(reset_type_names[reset_type]));

	/* Soft reset does not touch the index file nor the working tree
	 * at all, but requires them in a good order.  Other resets reset
	 * the index file to the tree object we are switching to. */
	if (reset_type == SOFT)
		die_if_unmerged_cache(reset_type);
	else {
		int err;
		if (reset_type == KEEP)
			die_if_unmerged_cache(reset_type);
		err = reset_index_file(sha1, reset_type, quiet);
		if (reset_type == KEEP)
			err = err || reset_index_file(sha1, MIXED, quiet);
		if (err)
			die(_("Could not reset index file to revision '%s'."), rev);
	}

	/* Any resets update HEAD to the head being switched to,
	 * saving the previous head in ORIG_HEAD before. */
	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
		old_orig = sha1_old_orig;
	if (!get_sha1("HEAD", sha1_orig)) {
		orig = sha1_orig;
		set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
		update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	}
	else if (old_orig)
		delete_ref("ORIG_HEAD", old_orig, 0);
	set_reflog_message(&msg, "updating HEAD", rev);
	update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);

	switch (reset_type) {
	case HARD:
		if (!update_ref_status && !quiet)
			print_new_head_line(commit);
		break;
	case SOFT: /* Nothing else to do. */
		break;
	case MIXED: /* Report what has not been updated. */
		update_index_refresh(0, NULL,
				quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
		break;
	}

	remove_branch_state();

	strbuf_release(&msg);

	return update_ref_status;
}

static int delete_branches(int argc, const char **argv, int force, int kinds,
			   int quiet)
{
	struct commit *head_rev = NULL;
	unsigned char sha1[20];
	char *name = NULL;
	const char *fmt;
	int i;
	int ret = 0;
	int remote_branch = 0;
	struct strbuf bname = STRBUF_INIT;

	switch (kinds) {
	case FILTER_REFS_REMOTES:
		fmt = "refs/remotes/%s";
		/* For subsequent UI messages */
		remote_branch = 1;

		force = 1;
		break;
	case FILTER_REFS_BRANCHES:
		fmt = "refs/heads/%s";
		break;
	default:
		die(_("cannot use -a with -d"));
	}

	if (!force) {
		head_rev = lookup_commit_reference(head_sha1);
		if (!head_rev)
			die(_("Couldn't look up commit object for HEAD"));
	}
	for (i = 0; i < argc; i++, strbuf_release(&bname)) {
		char *target = NULL;
		int flags = 0;

		strbuf_branchname(&bname, argv[i]);
		free(name);
		name = mkpathdup(fmt, bname.buf);

		if (kinds == FILTER_REFS_BRANCHES) {
			const struct worktree *wt =
				find_shared_symref("HEAD", name);
			if (wt) {
				error(_("Cannot delete branch '%s' "
					"checked out at '%s'"),
				      bname.buf, wt->path);
				ret = 1;
				continue;
			}
		}

		target = resolve_refdup(name,
					RESOLVE_REF_READING
					| RESOLVE_REF_NO_RECURSE
					| RESOLVE_REF_ALLOW_BAD_NAME,
					sha1, &flags);
		if (!target) {
			error(remote_branch
			      ? _("remote-tracking branch '%s' not found.")
			      : _("branch '%s' not found."), bname.buf);
			ret = 1;
			continue;
		}

		if (!(flags & (REF_ISSYMREF|REF_ISBROKEN)) &&
		    check_branch_commit(bname.buf, name, sha1, head_rev, kinds,
					force)) {
			ret = 1;
			goto next;
		}

		if (delete_ref(name, is_null_sha1(sha1) ? NULL : sha1,
			       REF_NODEREF)) {
			error(remote_branch
			      ? _("Error deleting remote-tracking branch '%s'")
			      : _("Error deleting branch '%s'"),
			      bname.buf);
			ret = 1;
			goto next;
		}
		if (!quiet) {
			printf(remote_branch
			       ? _("Deleted remote-tracking branch %s (was %s).\n")
			       : _("Deleted branch %s (was %s).\n"),
			       bname.buf,
			       (flags & REF_ISBROKEN) ? "broken"
			       : (flags & REF_ISSYMREF) ? target
			       : find_unique_abbrev(sha1, DEFAULT_ABBREV));
		}
		delete_branch_config(bname.buf);

	next:
		free(target);
	}

	free(name);

	return(ret);
}