t/unit-tests: fix typos

[git/gitster.git] / builtin / branch.c

/*
 * Builtin "git branch"
 *
 * Copyright (c) 2006 Kristian Høgsberg <krh@redhat.com>
 * Based on git-branch.sh by Junio C Hamano.
 */
#define USE_THE_REPOSITORY_VARIABLE
#include "builtin.h"
#include "config.h"
#include "color.h"
#include "editor.h"
#include "environment.h"
#include "refs.h"
#include "commit.h"
#include "gettext.h"
#include "object-name.h"
#include "remote.h"
#include "parse-options.h"
#include "branch.h"
#include "path.h"
#include "string-list.h"
#include "column.h"
#include "utf8.h"
#include "ref-filter.h"
#include "worktree.h"
#include "help.h"
#include "advice.h"
#include "commit-reach.h"

static const char * const builtin_branch_usage[] = {
        N_("git branch [<options>] [-r | -a] [--merged] [--no-merged]"),
        N_("git branch [<options>] [-f] [--recurse-submodules] <branch-name> [<start-point>]"),
        N_("git branch [<options>] [-l] [<pattern>...]"),
        N_("git branch [<options>] [-r] (-d | -D) <branch-name>..."),
        N_("git branch [<options>] (-m | -M) [<old-branch>] <new-branch>"),
        N_("git branch [<options>] (-c | -C) [<old-branch>] <new-branch>"),
        N_("git branch [<options>] [-r | -a] [--points-at]"),
        N_("git branch [<options>] [-r | -a] [--format]"),
        NULL
};

static const char *head;
static struct object_id head_oid;
static int recurse_submodules = 0;
static int submodule_propagate_branches = 0;

static int branch_use_color = -1;
static char branch_colors[][COLOR_MAXLEN] = {
        GIT_COLOR_RESET,
        GIT_COLOR_NORMAL,       /* PLAIN */
        GIT_COLOR_RED,          /* REMOTE */
        GIT_COLOR_NORMAL,       /* LOCAL */
        GIT_COLOR_GREEN,        /* CURRENT */
        GIT_COLOR_BLUE,         /* UPSTREAM */
        GIT_COLOR_CYAN,         /* WORKTREE */
};
enum color_branch {
        BRANCH_COLOR_RESET = 0,
        BRANCH_COLOR_PLAIN = 1,
        BRANCH_COLOR_REMOTE = 2,
        BRANCH_COLOR_LOCAL = 3,
        BRANCH_COLOR_CURRENT = 4,
        BRANCH_COLOR_UPSTREAM = 5,
        BRANCH_COLOR_WORKTREE = 6
};

static const char *color_branch_slots[] = {
        [BRANCH_COLOR_RESET]    = "reset",
        [BRANCH_COLOR_PLAIN]    = "plain",
        [BRANCH_COLOR_REMOTE]   = "remote",
        [BRANCH_COLOR_LOCAL]    = "local",
        [BRANCH_COLOR_CURRENT]  = "current",
        [BRANCH_COLOR_UPSTREAM] = "upstream",
        [BRANCH_COLOR_WORKTREE] = "worktree",
};

static struct string_list output = STRING_LIST_INIT_DUP;
static unsigned int colopts;

define_list_config_array(color_branch_slots);

static int git_branch_config(const char *var, const char *value,
                             const struct config_context *ctx, void *cb)
{
        const char *slot_name;

        if (!strcmp(var, "branch.sort")) {
                if (!value)
                        return config_error_nonbool(var);
                string_list_append(cb, value);
                return 0;
        }

        if (starts_with(var, "column."))
                return git_column_config(var, value, "branch", &colopts);
        if (!strcmp(var, "color.branch")) {
                branch_use_color = git_config_colorbool(var, value);
                return 0;
        }
        if (skip_prefix(var, "color.branch.", &slot_name)) {
                int slot = LOOKUP_CONFIG(color_branch_slots, slot_name);
                if (slot < 0)
                        return 0;
                if (!value)
                        return config_error_nonbool(var);
                return color_parse(value, branch_colors[slot]);
        }
        if (!strcmp(var, "submodule.recurse")) {
                recurse_submodules = git_config_bool(var, value);
                return 0;
        }
        if (!strcasecmp(var, "submodule.propagateBranches")) {
                submodule_propagate_branches = git_config_bool(var, value);
                return 0;
        }

        if (git_color_config(var, value, cb) < 0)
                return -1;

        return git_default_config(var, value, ctx, cb);
}

static const char *branch_get_color(enum color_branch ix)
{
        if (want_color(branch_use_color))
                return branch_colors[ix];
        return "";
}

static int branch_merged(int kind, const char *name,
                         struct commit *rev, struct commit *head_rev)
{
        /*
         * This checks whether the merge bases of branch and HEAD (or
         * the other branch this branch builds upon) contains the
         * branch, which means that the branch has already been merged
         * safely to HEAD (or the other branch).
         */
        struct commit *reference_rev = NULL;
        const char *reference_name = NULL;
        void *reference_name_to_free = NULL;
        int merged;

        if (kind == FILTER_REFS_BRANCHES) {
                struct branch *branch = branch_get(name);
                const char *upstream = branch_get_upstream(branch, NULL);
                struct object_id oid;

                if (upstream &&
                    (reference_name = reference_name_to_free =
                     refs_resolve_refdup(get_main_ref_store(the_repository), upstream, RESOLVE_REF_READING,
                                         &oid, NULL)) != NULL)
                        reference_rev = lookup_commit_reference(the_repository,
                                                                &oid);
        }
        if (!reference_rev)
                reference_rev = head_rev;

        merged = reference_rev ? repo_in_merge_bases(the_repository, rev,
                                                     reference_rev) : 0;
        if (merged < 0)
                exit(128);

        /*
         * After the safety valve is fully redefined to "check with
         * upstream, if any, otherwise with HEAD", we should just
         * return the result of the repo_in_merge_bases() above without
         * any of the following code, but during the transition period,
         * a gentle reminder is in order.
         */
        if (head_rev != reference_rev) {
                int expect = head_rev ? repo_in_merge_bases(the_repository, rev, head_rev) : 0;
                if (expect < 0)
                        exit(128);
                if (expect == merged)
                        ; /* okay */
                else if (merged)
                        warning(_("deleting branch '%s' that has been merged to\n"
                                "         '%s', but not yet merged to HEAD"),
                                name, reference_name);
                else
                        warning(_("not deleting branch '%s' that is not yet merged to\n"
                                "         '%s', even though it is merged to HEAD"),
                                name, reference_name);
        }
        free(reference_name_to_free);
        return merged;
}

static int check_branch_commit(const char *branchname, const char *refname,
                               const struct object_id *oid, struct commit *head_rev,
                               int kinds, int force)
{
        struct commit *rev = lookup_commit_reference(the_repository, oid);
        if (!force && !rev) {
                error(_("couldn't look up commit object for '%s'"), refname);
                return -1;
        }
        if (!force && !branch_merged(kinds, branchname, rev, head_rev)) {
                error(_("the branch '%s' is not fully merged"), branchname);
                advise_if_enabled(ADVICE_FORCE_DELETE_BRANCH,
                                  _("If you are sure you want to delete it, "
                                  "run 'git branch -D %s'"), branchname);
                return -1;
        }
        return 0;
}

static void delete_branch_config(const char *branchname)
{
        struct strbuf buf = STRBUF_INIT;
        strbuf_addf(&buf, "branch.%s", branchname);
        if (repo_config_rename_section(the_repository, buf.buf, NULL) < 0)
                warning(_("update of config-file failed"));
        strbuf_release(&buf);
}

static int delete_branches(int argc, const char **argv, int force, int kinds,
                           int quiet)
{
        struct commit *head_rev = NULL;
        struct object_id oid;
        char *name = NULL;
        const char *fmt;
        int i;
        int ret = 0;
        int remote_branch = 0;
        struct strbuf bname = STRBUF_INIT;
        unsigned allowed_interpret;
        struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
        struct string_list_item *item;
        int branch_name_pos;
        const char *fmt_remotes = "refs/remotes/%s";

        switch (kinds) {
        case FILTER_REFS_REMOTES:
                fmt = fmt_remotes;
                /* For subsequent UI messages */
                remote_branch = 1;
                allowed_interpret = INTERPRET_BRANCH_REMOTE;

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

        if (!force)
                head_rev = lookup_commit_reference(the_repository, &head_oid);

        for (i = 0; i < argc; i++, strbuf_reset(&bname)) {
                char *target = NULL;
                int flags = 0;

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

                if (kinds == FILTER_REFS_BRANCHES) {
                        const char *path;
                        if ((path = branch_checked_out(name))) {
                                error(_("cannot delete branch '%s' "
                                        "used by worktree at '%s'"),
                                      bname.buf, path);
                                ret = 1;
                                continue;
                        }
                }

                target = refs_resolve_refdup(get_main_ref_store(the_repository),
                                             name,
                                             RESOLVE_REF_READING
                                             | RESOLVE_REF_NO_RECURSE
                                             | RESOLVE_REF_ALLOW_BAD_NAME,
                                             &oid, &flags);
                if (!target) {
                        if (remote_branch) {
                                error(_("remote-tracking branch '%s' not found"), bname.buf);
                        } else {
                                char *virtual_name = mkpathdup(fmt_remotes, bname.buf);
                                char *virtual_target = refs_resolve_refdup(get_main_ref_store(the_repository),
                                                                           virtual_name,
                                                                           RESOLVE_REF_READING
                                                                           | RESOLVE_REF_NO_RECURSE
                                                                           | RESOLVE_REF_ALLOW_BAD_NAME,
                                                                           &oid,
                                                                           &flags);
                                FREE_AND_NULL(virtual_name);

                                if (virtual_target)
                                        error(_("branch '%s' not found.\n"
                                                "Did you forget --remote?"),
                                                bname.buf);
                                else
                                        error(_("branch '%s' not found"), bname.buf);
                                FREE_AND_NULL(virtual_target);
                        }
                        ret = 1;
                        continue;
                }

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

                item = string_list_append(&refs_to_delete, name);
                item->util = xstrdup((flags & REF_ISBROKEN) ? "broken"
                                    : (flags & REF_ISSYMREF) ? target
                                    : repo_find_unique_abbrev(the_repository, &oid, DEFAULT_ABBREV));

        next:
                free(target);
        }

        if (refs_delete_refs(get_main_ref_store(the_repository), NULL, &refs_to_delete, REF_NO_DEREF))
                ret = 1;

        for_each_string_list_item(item, &refs_to_delete) {
                char *describe_ref = item->util;
                char *name = item->string;
                if (!refs_ref_exists(get_main_ref_store(the_repository), name)) {
                        char *refname = name + branch_name_pos;
                        if (!quiet)
                                printf(remote_branch
                                        ? _("Deleted remote-tracking branch %s (was %s).\n")
                                        : _("Deleted branch %s (was %s).\n"),
                                        name + branch_name_pos, describe_ref);

                        delete_branch_config(refname);
                }
                free(describe_ref);
        }
        string_list_clear(&refs_to_delete, 0);

        free(name);
        strbuf_release(&bname);

        return ret;
}

static int calc_maxwidth(struct ref_array *refs, int remote_bonus)
{
        int i, max = 0;
        for (i = 0; i < refs->nr; i++) {
                struct ref_array_item *it = refs->items[i];
                const char *desc = it->refname;
                int w;

                skip_prefix(it->refname, "refs/heads/", &desc);
                skip_prefix(it->refname, "refs/remotes/", &desc);
                if (it->kind == FILTER_REFS_DETACHED_HEAD) {
                        char *head_desc = get_head_description();
                        w = utf8_strwidth(head_desc);
                        free(head_desc);
                } else
                        w = utf8_strwidth(desc);

                if (it->kind == FILTER_REFS_REMOTES)
                        w += remote_bonus;
                if (w > max)
                        max = w;
        }
        return max;
}

static const char *quote_literal_for_format(const char *s)
{
        static struct strbuf buf = STRBUF_INIT;

        strbuf_reset(&buf);
        while (strbuf_expand_step(&buf, &s))
                strbuf_addstr(&buf, "%%");
        return buf.buf;
}

static char *build_format(struct ref_filter *filter, int maxwidth, const char *remote_prefix)
{
        struct strbuf fmt = STRBUF_INIT;
        struct strbuf local = STRBUF_INIT;
        struct strbuf remote = STRBUF_INIT;

        strbuf_addf(&local, "%%(if)%%(HEAD)%%(then)* %s%%(else)%%(if)%%(worktreepath)%%(then)+ %s%%(else)  %s%%(end)%%(end)",
                        branch_get_color(BRANCH_COLOR_CURRENT),
                        branch_get_color(BRANCH_COLOR_WORKTREE),
                        branch_get_color(BRANCH_COLOR_LOCAL));
        strbuf_addf(&remote, "  %s",
                    branch_get_color(BRANCH_COLOR_REMOTE));

        if (filter->verbose) {
                struct strbuf obname = STRBUF_INIT;

                if (filter->abbrev < 0)
                        strbuf_addf(&obname, "%%(objectname:short)");
                else if (!filter->abbrev)
                        strbuf_addf(&obname, "%%(objectname)");
                else
                        strbuf_addf(&obname, "%%(objectname:short=%d)", filter->abbrev);

                strbuf_addf(&local, "%%(align:%d,left)%%(refname:lstrip=2)%%(end)", maxwidth);
                strbuf_addstr(&local, branch_get_color(BRANCH_COLOR_RESET));
                strbuf_addf(&local, " %s ", obname.buf);

                if (filter->verbose > 1)
                {
                        strbuf_addf(&local, "%%(if:notequals=*)%%(HEAD)%%(then)%%(if)%%(worktreepath)%%(then)(%s%%(worktreepath)%s) %%(end)%%(end)",
                                    branch_get_color(BRANCH_COLOR_WORKTREE), branch_get_color(BRANCH_COLOR_RESET));
                        strbuf_addf(&local, "%%(if)%%(upstream)%%(then)[%s%%(upstream:short)%s%%(if)%%(upstream:track)"
                                    "%%(then): %%(upstream:track,nobracket)%%(end)] %%(end)%%(contents:subject)",
                                    branch_get_color(BRANCH_COLOR_UPSTREAM), branch_get_color(BRANCH_COLOR_RESET));
                }
                else
                        strbuf_addf(&local, "%%(if)%%(upstream:track)%%(then)%%(upstream:track) %%(end)%%(contents:subject)");

                strbuf_addf(&remote, "%%(align:%d,left)%s%%(refname:lstrip=2)%%(end)%s"
                            "%%(if)%%(symref)%%(then) -> %%(symref:short)"
                            "%%(else) %s %%(contents:subject)%%(end)",
                            maxwidth, quote_literal_for_format(remote_prefix),
                            branch_get_color(BRANCH_COLOR_RESET), obname.buf);
                strbuf_release(&obname);
        } else {
                strbuf_addf(&local, "%%(refname:lstrip=2)%s%%(if)%%(symref)%%(then) -> %%(symref:short)%%(end)",
                            branch_get_color(BRANCH_COLOR_RESET));
                strbuf_addf(&remote, "%s%%(refname:lstrip=2)%s%%(if)%%(symref)%%(then) -> %%(symref:short)%%(end)",
                            quote_literal_for_format(remote_prefix),
                            branch_get_color(BRANCH_COLOR_RESET));
        }

        strbuf_addf(&fmt, "%%(if:notequals=refs/remotes)%%(refname:rstrip=-2)%%(then)%s%%(else)%s%%(end)", local.buf, remote.buf);

        strbuf_release(&local);
        strbuf_release(&remote);
        return strbuf_detach(&fmt, NULL);
}

static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sorting,
                           struct ref_format *format, struct string_list *output)
{
        int i;
        struct ref_array array;
        int maxwidth = 0;
        const char *remote_prefix = "";
        char *to_free = NULL;

        /*
         * If we are listing more than just remote branches,
         * then remote branches will have a "remotes/" prefix.
         * We need to account for this in the width.
         */
        if (filter->kind != FILTER_REFS_REMOTES)
                remote_prefix = "remotes/";

        memset(&array, 0, sizeof(array));

        filter_refs(&array, filter, filter->kind);

        if (filter->verbose)
                maxwidth = calc_maxwidth(&array, strlen(remote_prefix));

        if (!format->format)
                format->format = to_free = build_format(filter, maxwidth, remote_prefix);
        format->use_color = branch_use_color;

        if (verify_ref_format(format))
                die(_("unable to parse format string"));

        filter_ahead_behind(the_repository, format, &array);
        ref_array_sort(sorting, &array);

        if (column_active(colopts)) {
                struct strbuf out = STRBUF_INIT, err = STRBUF_INIT;

                assert(!filter->verbose && "--column and --verbose are incompatible");

                for (i = 0; i < array.nr; i++) {
                        strbuf_reset(&err);
                        strbuf_reset(&out);
                        if (format_ref_array_item(array.items[i], format, &out, &err))
                                die("%s", err.buf);

                        /* format to a string_list to let print_columns() do its job */
                        string_list_append(output, out.buf);
                }

                strbuf_release(&err);
                strbuf_release(&out);
        } else {
                print_formatted_ref_array(&array, format);
        }

        ref_array_clear(&array);
        free(to_free);
}

static void print_current_branch_name(void)
{
        int flags;
        const char *refname = refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
                                                      "HEAD", 0, NULL, &flags);
        const char *shortname;
        if (!refname)
                die(_("could not resolve HEAD"));
        else if (!(flags & REF_ISSYMREF))
                return;
        else if (skip_prefix(refname, "refs/heads/", &shortname))
                puts(shortname);
        else
                die(_("HEAD (%s) points outside of refs/heads/"), refname);
}

static void reject_rebase_or_bisect_branch(struct worktree **worktrees,
                                           const char *target)
{
        int i;

        for (i = 0; worktrees[i]; i++) {
                struct worktree *wt = worktrees[i];

                if (!wt->is_detached)
                        continue;

                if (is_worktree_being_rebased(wt, target))
                        die(_("branch %s is being rebased at %s"),
                            target, wt->path);

                if (is_worktree_being_bisected(wt, target))
                        die(_("branch %s is being bisected at %s"),
                            target, wt->path);
        }
}

/*
 * Update all per-worktree HEADs pointing at the old ref to point the new ref.
 * This will be used when renaming a branch. Returns 0 if successful, non-zero
 * otherwise.
 */
static int replace_each_worktree_head_symref(struct worktree **worktrees,
                                             const char *oldref, const char *newref,
                                             const char *logmsg)
{
        int ret = 0;
        int i;

        for (i = 0; worktrees[i]; i++) {
                struct ref_store *refs;

                if (worktrees[i]->is_detached)
                        continue;
                if (!worktrees[i]->head_ref)
                        continue;
                if (strcmp(oldref, worktrees[i]->head_ref))
                        continue;

                refs = get_worktree_ref_store(worktrees[i]);
                if (refs_update_symref(refs, "HEAD", newref, logmsg))
                        ret = error(_("HEAD of working tree %s is not updated"),
                                    worktrees[i]->path);
        }

        return ret;
}

#define IS_HEAD 1
#define IS_ORPHAN 2

static void copy_or_rename_branch(const char *oldname, const char *newname, int copy, int force)
{
        struct strbuf oldref = STRBUF_INIT, newref = STRBUF_INIT, logmsg = STRBUF_INIT;
        struct strbuf oldsection = STRBUF_INIT, newsection = STRBUF_INIT;
        const char *interpreted_oldname = NULL;
        const char *interpreted_newname = NULL;
        int recovery = 0, oldref_usage = 0;
        struct worktree **worktrees = get_worktrees();

        if (strbuf_check_branch_ref(&oldref, oldname)) {
                /*
                 * Bad name --- this could be an attempt to rename a
                 * ref that we used to allow to be created by accident.
                 */
                if (refs_ref_exists(get_main_ref_store(the_repository), oldref.buf))
                        recovery = 1;
                else {
                        int code = die_message(_("invalid branch name: '%s'"), oldname);
                        advise_if_enabled(ADVICE_REF_SYNTAX,
                                          _("See `man git check-ref-format`"));
                        exit(code);
                }
        }

        for (int i = 0; worktrees[i]; i++) {
                struct worktree *wt = worktrees[i];

                if (wt->head_ref && !strcmp(oldref.buf, wt->head_ref)) {
                        oldref_usage |= IS_HEAD;
                        if (is_null_oid(&wt->head_oid))
                                oldref_usage |= IS_ORPHAN;
                        break;
                }
        }

        if ((copy || !(oldref_usage & IS_HEAD)) && !refs_ref_exists(get_main_ref_store(the_repository), oldref.buf)) {
                if (oldref_usage & IS_HEAD)
                        die(_("no commit on branch '%s' yet"), oldname);
                else
                        die(_("no branch named '%s'"), oldname);
        }

        /*
         * A command like "git branch -M currentbranch currentbranch" cannot
         * cause the worktree to become inconsistent with HEAD, so allow it.
         */
        if (!strcmp(oldname, newname))
                validate_branchname(newname, &newref);
        else
                validate_new_branchname(newname, &newref, force);

        reject_rebase_or_bisect_branch(worktrees, oldref.buf);

        if (!skip_prefix(oldref.buf, "refs/heads/", &interpreted_oldname) ||
            !skip_prefix(newref.buf, "refs/heads/", &interpreted_newname)) {
                BUG("expected prefix missing for refs");
        }

        if (copy)
                strbuf_addf(&logmsg, "Branch: copied %s to %s",
                            oldref.buf, newref.buf);
        else
                strbuf_addf(&logmsg, "Branch: renamed %s to %s",
                            oldref.buf, newref.buf);

        if (!copy && !(oldref_usage & IS_ORPHAN) &&
            refs_rename_ref(get_main_ref_store(the_repository), oldref.buf, newref.buf, logmsg.buf))
                die(_("branch rename failed"));
        if (copy && refs_copy_existing_ref(get_main_ref_store(the_repository), oldref.buf, newref.buf, logmsg.buf))
                die(_("branch copy failed"));

        if (recovery) {
                if (copy)
                        warning(_("created a copy of a misnamed branch '%s'"),
                                interpreted_oldname);
                else
                        warning(_("renamed a misnamed branch '%s' away"),
                                interpreted_oldname);
        }

        if (!copy && (oldref_usage & IS_HEAD) &&
            replace_each_worktree_head_symref(worktrees, oldref.buf, newref.buf,
                                              logmsg.buf))
                die(_("branch renamed to %s, but HEAD is not updated"), newname);

        strbuf_release(&logmsg);

        strbuf_addf(&oldsection, "branch.%s", interpreted_oldname);
        strbuf_addf(&newsection, "branch.%s", interpreted_newname);
        if (!copy && repo_config_rename_section(the_repository, oldsection.buf, newsection.buf) < 0)
                die(_("branch is renamed, but update of config-file failed"));
        if (copy && strcmp(interpreted_oldname, interpreted_newname) &&
            repo_config_copy_section(the_repository, oldsection.buf, newsection.buf) < 0)
                die(_("branch is copied, but update of config-file failed"));
        strbuf_release(&oldref);
        strbuf_release(&newref);
        strbuf_release(&oldsection);
        strbuf_release(&newsection);
        free_worktrees(worktrees);
}

static GIT_PATH_FUNC(edit_description, "EDIT_DESCRIPTION")

static int edit_branch_description(const char *branch_name)
{
        int exists;
        struct strbuf buf = STRBUF_INIT;
        struct strbuf name = STRBUF_INIT;

        exists = !read_branch_desc(&buf, branch_name);
        if (!buf.len || buf.buf[buf.len-1] != '\n')
                strbuf_addch(&buf, '\n');
        strbuf_commented_addf(&buf, comment_line_str,
                    _("Please edit the description for the branch\n"
                      "  %s\n"
                      "Lines starting with '%s' will be stripped.\n"),
                    branch_name, comment_line_str);
        write_file_buf(edit_description(), buf.buf, buf.len);
        strbuf_reset(&buf);
        if (launch_editor(edit_description(), &buf, NULL)) {
                strbuf_release(&buf);
                return -1;
        }
        strbuf_stripspace(&buf, comment_line_str);

        strbuf_addf(&name, "branch.%s.description", branch_name);
        if (buf.len || exists)
                git_config_set(name.buf, buf.len ? buf.buf : NULL);
        strbuf_release(&name);
        strbuf_release(&buf);

        return 0;
}

int cmd_branch(int argc,
               const char **argv,
               const char *prefix,
               struct repository *repo UNUSED)
{
        /* possible actions */
        int delete = 0, rename = 0, copy = 0, list = 0,
            unset_upstream = 0, show_current = 0, edit_description = 0;
        const char *new_upstream = NULL;
        int noncreate_actions = 0;
        /* possible options */
        int reflog = 0, quiet = 0, icase = 0, force = 0,
            recurse_submodules_explicit = 0;
        enum branch_track track;
        struct ref_filter filter = REF_FILTER_INIT;
        static struct ref_sorting *sorting;
        struct string_list sorting_options = STRING_LIST_INIT_DUP;
        struct ref_format format = REF_FORMAT_INIT;

        struct option options[] = {
                OPT_GROUP(N_("Generic options")),
                OPT__VERBOSE(&filter.verbose,
                        N_("show hash and subject, give twice for upstream branch")),
                OPT__QUIET(&quiet, N_("suppress informational messages")),
                OPT_CALLBACK_F('t', "track",  &track, "(direct|inherit)",
                        N_("set branch tracking configuration"),
                        PARSE_OPT_OPTARG,
                        parse_opt_tracking_mode),
                OPT_SET_INT_F(0, "set-upstream", &track, N_("do not use"),
                        BRANCH_TRACK_OVERRIDE, PARSE_OPT_HIDDEN),
                OPT_STRING('u', "set-upstream-to", &new_upstream, N_("upstream"), N_("change the upstream info")),
                OPT_BOOL(0, "unset-upstream", &unset_upstream, N_("unset the upstream info")),
                OPT__COLOR(&branch_use_color, N_("use colored output")),
                OPT_SET_INT_F('r', "remotes",     &filter.kind, N_("act on remote-tracking branches"),
                              FILTER_REFS_REMOTES,
                              PARSE_OPT_NONEG),
                OPT_CONTAINS(&filter.with_commit, N_("print only branches that contain the commit")),
                OPT_NO_CONTAINS(&filter.no_commit, N_("print only branches that don't contain the commit")),
                OPT_WITH(&filter.with_commit, N_("print only branches that contain the commit")),
                OPT_WITHOUT(&filter.no_commit, N_("print only branches that don't contain the commit")),
                OPT__ABBREV(&filter.abbrev),

                OPT_GROUP(N_("Specific git-branch actions:")),
                OPT_SET_INT_F('a', "all", &filter.kind, N_("list both remote-tracking and local branches"),
                              FILTER_REFS_REMOTES | FILTER_REFS_BRANCHES,
                              PARSE_OPT_NONEG),
                OPT_BIT('d', "delete", &delete, N_("delete fully merged branch"), 1),
                OPT_BIT('D', NULL, &delete, N_("delete branch (even if not merged)"), 2),
                OPT_BIT('m', "move", &rename, N_("move/rename a branch and its reflog"), 1),
                OPT_BIT('M', NULL, &rename, N_("move/rename a branch, even if target exists"), 2),
                OPT_BOOL(0, "omit-empty",  &format.array_opts.omit_empty,
                        N_("do not output a newline after empty formatted refs")),
                OPT_BIT('c', "copy", &copy, N_("copy a branch and its reflog"), 1),
                OPT_BIT('C', NULL, &copy, N_("copy a branch, even if target exists"), 2),
                OPT_BOOL('l', "list", &list, N_("list branch names")),
                OPT_BOOL(0, "show-current", &show_current, N_("show current branch name")),
                OPT_BOOL(0, "create-reflog", &reflog, N_("create the branch's reflog")),
                OPT_BOOL(0, "edit-description", &edit_description,
                         N_("edit the description for the branch")),
                OPT__FORCE(&force, N_("force creation, move/rename, deletion"), PARSE_OPT_NOCOMPLETE),
                OPT_MERGED(&filter, N_("print only branches that are merged")),
                OPT_NO_MERGED(&filter, N_("print only branches that are not merged")),
                OPT_COLUMN(0, "column", &colopts, N_("list branches in columns")),
                OPT_REF_SORT(&sorting_options),
                OPT_CALLBACK(0, "points-at", &filter.points_at, N_("object"),
                        N_("print only branches of the object"), parse_opt_object_name),
                OPT_BOOL('i', "ignore-case", &icase, N_("sorting and filtering are case insensitive")),
                OPT_BOOL(0, "recurse-submodules", &recurse_submodules_explicit, N_("recurse through submodules")),
                OPT_STRING(  0 , "format", &format.format, N_("format"), N_("format to use for the output")),
                OPT_END(),
        };

        setup_ref_filter_porcelain_msg();

        filter.kind = FILTER_REFS_BRANCHES;
        filter.abbrev = -1;

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

        /*
         * Try to set sort keys from config. If config does not set any,
         * fall back on default (refname) sorting.
         */
        git_config(git_branch_config, &sorting_options);
        if (!sorting_options.nr)
                string_list_append(&sorting_options, "refname");

        track = git_branch_track;

        head = refs_resolve_refdup(get_main_ref_store(the_repository), "HEAD",
                                   0, &head_oid, NULL);
        if (!head)
                die(_("failed to resolve HEAD as a valid ref"));
        if (!strcmp(head, "HEAD"))
                filter.detached = 1;
        else if (!skip_prefix(head, "refs/heads/", &head))
                die(_("HEAD not found below refs/heads!"));

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

        if (!delete && !rename && !copy && !edit_description && !new_upstream &&
            !show_current && !unset_upstream && argc == 0)
                list = 1;

        if (filter.with_commit || filter.no_commit ||
            filter.reachable_from || filter.unreachable_from || filter.points_at.nr)
                list = 1;

        noncreate_actions = !!delete + !!rename + !!copy + !!new_upstream +
                            !!show_current + !!list + !!edit_description +
                            !!unset_upstream;
        if (noncreate_actions > 1)
                usage_with_options(builtin_branch_usage, options);

        if (recurse_submodules_explicit) {
                if (!submodule_propagate_branches)
                        die(_("branch with --recurse-submodules can only be used if submodule.propagateBranches is enabled"));
                if (noncreate_actions)
                        die(_("--recurse-submodules can only be used to create branches"));
        }

        recurse_submodules =
                (recurse_submodules || recurse_submodules_explicit) &&
                submodule_propagate_branches;

        if (filter.abbrev == -1)
                filter.abbrev = DEFAULT_ABBREV;
        filter.ignore_case = icase;

        finalize_colopts(&colopts, -1);
        if (filter.verbose) {
                if (explicitly_enable_column(colopts))
                        die(_("options '%s' and '%s' cannot be used together"), "--column", "--verbose");
                colopts = 0;
        }

        if (force) {
                delete *= 2;
                rename *= 2;
                copy *= 2;
        }

        if (list)
                setup_auto_pager("branch", 1);

        UNLEAK(sorting_options);

        if (delete) {
                if (!argc)
                        die(_("branch name required"));
                return delete_branches(argc, argv, delete > 1, filter.kind, quiet);
        } else if (show_current) {
                print_current_branch_name();
                return 0;
        } else if (list) {
                /*  git branch --list also shows HEAD when it is detached */
                if ((filter.kind & FILTER_REFS_BRANCHES) && filter.detached)
                        filter.kind |= FILTER_REFS_DETACHED_HEAD;
                filter.name_patterns = argv;
                /*
                 * If no sorting parameter is given then we default to sorting
                 * by 'refname'. This would give us an alphabetically sorted
                 * array with the 'HEAD' ref at the beginning followed by
                 * local branches 'refs/heads/...' and finally remote-tracking
                 * branches 'refs/remotes/...'.
                 */
                sorting = ref_sorting_options(&sorting_options);
                ref_sorting_set_sort_flags_all(sorting, REF_SORTING_ICASE, icase);
                ref_sorting_set_sort_flags_all(
                        sorting, REF_SORTING_DETACHED_HEAD_FIRST, 1);
                print_ref_list(&filter, sorting, &format, &output);
                print_columns(&output, colopts, NULL);
                string_list_clear(&output, 0);
                ref_sorting_release(sorting);
                ref_filter_clear(&filter);
                ref_format_clear(&format);
                return 0;
        } else if (edit_description) {
                const char *branch_name;
                struct strbuf branch_ref = STRBUF_INIT;
                struct strbuf buf = STRBUF_INIT;
                int ret = 1; /* assume failure */

                if (!argc) {
                        if (filter.detached)
                                die(_("cannot give description to detached HEAD"));
                        branch_name = head;
                } else if (argc == 1) {
                        strbuf_branchname(&buf, argv[0], INTERPRET_BRANCH_LOCAL);
                        branch_name = buf.buf;
                } else {
                        die(_("cannot edit description of more than one branch"));
                }

                strbuf_addf(&branch_ref, "refs/heads/%s", branch_name);
                if (!refs_ref_exists(get_main_ref_store(the_repository), branch_ref.buf))
                        error((!argc || branch_checked_out(branch_ref.buf))
                              ? _("no commit on branch '%s' yet")
                              : _("no branch named '%s'"),
                              branch_name);
                else if (!edit_branch_description(branch_name))
                        ret = 0; /* happy */

                strbuf_release(&branch_ref);
                strbuf_release(&buf);

                return ret;
        } else if (copy || rename) {
                if (!argc)
                        die(_("branch name required"));
                else if ((argc == 1) && filter.detached)
                        die(copy? _("cannot copy the current branch while not on any")
                                : _("cannot rename the current branch while not on any"));
                else if (argc == 1)
                        copy_or_rename_branch(head, argv[0], copy, copy + rename > 1);
                else if (argc == 2)
                        copy_or_rename_branch(argv[0], argv[1], copy, copy + rename > 1);
                else
                        die(copy? _("too many branches for a copy operation")
                                : _("too many arguments for a rename operation"));
        } else if (new_upstream) {
                struct branch *branch;
                struct strbuf buf = STRBUF_INIT;

                if (!argc)
                        branch = branch_get(NULL);
                else if (argc == 1) {
                        strbuf_branchname(&buf, argv[0], INTERPRET_BRANCH_LOCAL);
                        branch = branch_get(buf.buf);
                } else
                        die(_("too many arguments to set new upstream"));

                if (!branch) {
                        if (!argc || !strcmp(argv[0], "HEAD"))
                                die(_("could not set upstream of HEAD to %s when "
                                      "it does not point to any branch"),
                                    new_upstream);
                        die(_("no such branch '%s'"), argv[0]);
                }

                if (!refs_ref_exists(get_main_ref_store(the_repository), branch->refname)) {
                        if (!argc || branch_checked_out(branch->refname))
                                die(_("no commit on branch '%s' yet"), branch->name);
                        die(_("branch '%s' does not exist"), branch->name);
                }

                dwim_and_setup_tracking(the_repository, branch->name,
                                        new_upstream, BRANCH_TRACK_OVERRIDE,
                                        quiet);
                strbuf_release(&buf);
        } else if (unset_upstream) {
                struct branch *branch;
                struct strbuf buf = STRBUF_INIT;

                if (!argc)
                        branch = branch_get(NULL);
                else if (argc == 1) {
                        strbuf_branchname(&buf, argv[0], INTERPRET_BRANCH_LOCAL);
                        branch = branch_get(buf.buf);
                } else
                        die(_("too many arguments to unset upstream"));

                if (!branch) {
                        if (!argc || !strcmp(argv[0], "HEAD"))
                                die(_("could not unset upstream of HEAD when "
                                      "it does not point to any branch"));
                        die(_("no such branch '%s'"), argv[0]);
                }

                if (!branch_has_merge_config(branch))
                        die(_("branch '%s' has no upstream information"), branch->name);

                strbuf_reset(&buf);
                strbuf_addf(&buf, "branch.%s.remote", branch->name);
                git_config_set_multivar(buf.buf, NULL, NULL, CONFIG_FLAGS_MULTI_REPLACE);
                strbuf_reset(&buf);
                strbuf_addf(&buf, "branch.%s.merge", branch->name);
                git_config_set_multivar(buf.buf, NULL, NULL, CONFIG_FLAGS_MULTI_REPLACE);
                strbuf_release(&buf);
        } else if (!noncreate_actions && argc > 0 && argc <= 2) {
                const char *branch_name = argv[0];
                const char *start_name = argc == 2 ? argv[1] : head;

                if (filter.kind != FILTER_REFS_BRANCHES)
                        die(_("the -a, and -r, options to 'git branch' do not take a branch name.\n"
                                  "Did you mean to use: -a|-r --list <pattern>?"));

                if (track == BRANCH_TRACK_OVERRIDE)
                        die(_("the '--set-upstream' option is no longer supported. Please use '--track' or '--set-upstream-to' instead"));

                if (recurse_submodules) {
                        create_branches_recursively(the_repository, branch_name,
                                                    start_name, NULL, force,
                                                    reflog, quiet, track, 0);
                        return 0;
                }
                create_branch(the_repository, branch_name, start_name, force, 0,
                              reflog, quiet, track, 0);
        } else
                usage_with_options(builtin_branch_usage, options);

        return 0;
}