builtin / checkout.con commit commit-reach: move walk methods from commit.c (5227c38)
   1#include "builtin.h"
   2#include "config.h"
   3#include "checkout.h"
   4#include "lockfile.h"
   5#include "parse-options.h"
   6#include "refs.h"
   7#include "object-store.h"
   8#include "commit.h"
   9#include "tree.h"
  10#include "tree-walk.h"
  11#include "cache-tree.h"
  12#include "unpack-trees.h"
  13#include "dir.h"
  14#include "run-command.h"
  15#include "merge-recursive.h"
  16#include "branch.h"
  17#include "diff.h"
  18#include "revision.h"
  19#include "remote.h"
  20#include "blob.h"
  21#include "xdiff-interface.h"
  22#include "ll-merge.h"
  23#include "resolve-undo.h"
  24#include "submodule-config.h"
  25#include "submodule.h"
  26
  27static const char * const checkout_usage[] = {
  28        N_("git checkout [<options>] <branch>"),
  29        N_("git checkout [<options>] [<branch>] -- <file>..."),
  30        NULL,
  31};
  32
  33struct checkout_opts {
  34        int patch_mode;
  35        int quiet;
  36        int merge;
  37        int force;
  38        int force_detach;
  39        int writeout_stage;
  40        int overwrite_ignore;
  41        int ignore_skipworktree;
  42        int ignore_other_worktrees;
  43        int show_progress;
  44
  45        const char *new_branch;
  46        const char *new_branch_force;
  47        const char *new_orphan_branch;
  48        int new_branch_log;
  49        enum branch_track track;
  50        struct diff_options diff_options;
  51
  52        int branch_exists;
  53        const char *prefix;
  54        struct pathspec pathspec;
  55        struct tree *source_tree;
  56};
  57
  58static int post_checkout_hook(struct commit *old_commit, struct commit *new_commit,
  59                              int changed)
  60{
  61        return run_hook_le(NULL, "post-checkout",
  62                           oid_to_hex(old_commit ? &old_commit->object.oid : &null_oid),
  63                           oid_to_hex(new_commit ? &new_commit->object.oid : &null_oid),
  64                           changed ? "1" : "0", NULL);
  65        /* "new_commit" can be NULL when checking out from the index before
  66           a commit exists. */
  67
  68}
  69
  70static int update_some(const struct object_id *oid, struct strbuf *base,
  71                const char *pathname, unsigned mode, int stage, void *context)
  72{
  73        int len;
  74        struct cache_entry *ce;
  75        int pos;
  76
  77        if (S_ISDIR(mode))
  78                return READ_TREE_RECURSIVE;
  79
  80        len = base->len + strlen(pathname);
  81        ce = xcalloc(1, cache_entry_size(len));
  82        oidcpy(&ce->oid, oid);
  83        memcpy(ce->name, base->buf, base->len);
  84        memcpy(ce->name + base->len, pathname, len - base->len);
  85        ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
  86        ce->ce_namelen = len;
  87        ce->ce_mode = create_ce_mode(mode);
  88
  89        /*
  90         * If the entry is the same as the current index, we can leave the old
  91         * entry in place. Whether it is UPTODATE or not, checkout_entry will
  92         * do the right thing.
  93         */
  94        pos = cache_name_pos(ce->name, ce->ce_namelen);
  95        if (pos >= 0) {
  96                struct cache_entry *old = active_cache[pos];
  97                if (ce->ce_mode == old->ce_mode &&
  98                    !oidcmp(&ce->oid, &old->oid)) {
  99                        old->ce_flags |= CE_UPDATE;
 100                        free(ce);
 101                        return 0;
 102                }
 103        }
 104
 105        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
 106        return 0;
 107}
 108
 109static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
 110{
 111        read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
 112
 113        /* update the index with the given tree's info
 114         * for all args, expanding wildcards, and exit
 115         * with any non-zero return code.
 116         */
 117        return 0;
 118}
 119
 120static int skip_same_name(const struct cache_entry *ce, int pos)
 121{
 122        while (++pos < active_nr &&
 123               !strcmp(active_cache[pos]->name, ce->name))
 124                ; /* skip */
 125        return pos;
 126}
 127
 128static int check_stage(int stage, const struct cache_entry *ce, int pos)
 129{
 130        while (pos < active_nr &&
 131               !strcmp(active_cache[pos]->name, ce->name)) {
 132                if (ce_stage(active_cache[pos]) == stage)
 133                        return 0;
 134                pos++;
 135        }
 136        if (stage == 2)
 137                return error(_("path '%s' does not have our version"), ce->name);
 138        else
 139                return error(_("path '%s' does not have their version"), ce->name);
 140}
 141
 142static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
 143{
 144        unsigned seen = 0;
 145        const char *name = ce->name;
 146
 147        while (pos < active_nr) {
 148                ce = active_cache[pos];
 149                if (strcmp(name, ce->name))
 150                        break;
 151                seen |= (1 << ce_stage(ce));
 152                pos++;
 153        }
 154        if ((stages & seen) != stages)
 155                return error(_("path '%s' does not have all necessary versions"),
 156                             name);
 157        return 0;
 158}
 159
 160static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
 161                          const struct checkout *state)
 162{
 163        while (pos < active_nr &&
 164               !strcmp(active_cache[pos]->name, ce->name)) {
 165                if (ce_stage(active_cache[pos]) == stage)
 166                        return checkout_entry(active_cache[pos], state, NULL);
 167                pos++;
 168        }
 169        if (stage == 2)
 170                return error(_("path '%s' does not have our version"), ce->name);
 171        else
 172                return error(_("path '%s' does not have their version"), ce->name);
 173}
 174
 175static int checkout_merged(int pos, const struct checkout *state)
 176{
 177        struct cache_entry *ce = active_cache[pos];
 178        const char *path = ce->name;
 179        mmfile_t ancestor, ours, theirs;
 180        int status;
 181        struct object_id oid;
 182        mmbuffer_t result_buf;
 183        struct object_id threeway[3];
 184        unsigned mode = 0;
 185
 186        memset(threeway, 0, sizeof(threeway));
 187        while (pos < active_nr) {
 188                int stage;
 189                stage = ce_stage(ce);
 190                if (!stage || strcmp(path, ce->name))
 191                        break;
 192                oidcpy(&threeway[stage - 1], &ce->oid);
 193                if (stage == 2)
 194                        mode = create_ce_mode(ce->ce_mode);
 195                pos++;
 196                ce = active_cache[pos];
 197        }
 198        if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
 199                return error(_("path '%s' does not have necessary versions"), path);
 200
 201        read_mmblob(&ancestor, &threeway[0]);
 202        read_mmblob(&ours, &threeway[1]);
 203        read_mmblob(&theirs, &threeway[2]);
 204
 205        /*
 206         * NEEDSWORK: re-create conflicts from merges with
 207         * merge.renormalize set, too
 208         */
 209        status = ll_merge(&result_buf, path, &ancestor, "base",
 210                          &ours, "ours", &theirs, "theirs", NULL);
 211        free(ancestor.ptr);
 212        free(ours.ptr);
 213        free(theirs.ptr);
 214        if (status < 0 || !result_buf.ptr) {
 215                free(result_buf.ptr);
 216                return error(_("path '%s': cannot merge"), path);
 217        }
 218
 219        /*
 220         * NEEDSWORK:
 221         * There is absolutely no reason to write this as a blob object
 222         * and create a phony cache entry.  This hack is primarily to get
 223         * to the write_entry() machinery that massages the contents to
 224         * work-tree format and writes out which only allows it for a
 225         * cache entry.  The code in write_entry() needs to be refactored
 226         * to allow us to feed a <buffer, size, mode> instead of a cache
 227         * entry.  Such a refactoring would help merge_recursive as well
 228         * (it also writes the merge result to the object database even
 229         * when it may contain conflicts).
 230         */
 231        if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
 232                die(_("Unable to add merge result for '%s'"), path);
 233        free(result_buf.ptr);
 234        ce = make_cache_entry(mode, oid.hash, path, 2, 0);
 235        if (!ce)
 236                die(_("make_cache_entry failed for path '%s'"), path);
 237        status = checkout_entry(ce, state, NULL);
 238        free(ce);
 239        return status;
 240}
 241
 242static int checkout_paths(const struct checkout_opts *opts,
 243                          const char *revision)
 244{
 245        int pos;
 246        struct checkout state = CHECKOUT_INIT;
 247        static char *ps_matched;
 248        struct object_id rev;
 249        struct commit *head;
 250        int errs = 0;
 251        struct lock_file lock_file = LOCK_INIT;
 252
 253        if (opts->track != BRANCH_TRACK_UNSPECIFIED)
 254                die(_("'%s' cannot be used with updating paths"), "--track");
 255
 256        if (opts->new_branch_log)
 257                die(_("'%s' cannot be used with updating paths"), "-l");
 258
 259        if (opts->force && opts->patch_mode)
 260                die(_("'%s' cannot be used with updating paths"), "-f");
 261
 262        if (opts->force_detach)
 263                die(_("'%s' cannot be used with updating paths"), "--detach");
 264
 265        if (opts->merge && opts->patch_mode)
 266                die(_("'%s' cannot be used with %s"), "--merge", "--patch");
 267
 268        if (opts->force && opts->merge)
 269                die(_("'%s' cannot be used with %s"), "-f", "-m");
 270
 271        if (opts->new_branch)
 272                die(_("Cannot update paths and switch to branch '%s' at the same time."),
 273                    opts->new_branch);
 274
 275        if (opts->patch_mode)
 276                return run_add_interactive(revision, "--patch=checkout",
 277                                           &opts->pathspec);
 278
 279        hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 280        if (read_cache_preload(&opts->pathspec) < 0)
 281                return error(_("index file corrupt"));
 282
 283        if (opts->source_tree)
 284                read_tree_some(opts->source_tree, &opts->pathspec);
 285
 286        ps_matched = xcalloc(opts->pathspec.nr, 1);
 287
 288        /*
 289         * Make sure all pathspecs participated in locating the paths
 290         * to be checked out.
 291         */
 292        for (pos = 0; pos < active_nr; pos++) {
 293                struct cache_entry *ce = active_cache[pos];
 294                ce->ce_flags &= ~CE_MATCHED;
 295                if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
 296                        continue;
 297                if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
 298                        /*
 299                         * "git checkout tree-ish -- path", but this entry
 300                         * is in the original index; it will not be checked
 301                         * out to the working tree and it does not matter
 302                         * if pathspec matched this entry.  We will not do
 303                         * anything to this entry at all.
 304                         */
 305                        continue;
 306                /*
 307                 * Either this entry came from the tree-ish we are
 308                 * checking the paths out of, or we are checking out
 309                 * of the index.
 310                 *
 311                 * If it comes from the tree-ish, we already know it
 312                 * matches the pathspec and could just stamp
 313                 * CE_MATCHED to it from update_some(). But we still
 314                 * need ps_matched and read_tree_recursive (and
 315                 * eventually tree_entry_interesting) cannot fill
 316                 * ps_matched yet. Once it can, we can avoid calling
 317                 * match_pathspec() for _all_ entries when
 318                 * opts->source_tree != NULL.
 319                 */
 320                if (ce_path_match(ce, &opts->pathspec, ps_matched))
 321                        ce->ce_flags |= CE_MATCHED;
 322        }
 323
 324        if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
 325                free(ps_matched);
 326                return 1;
 327        }
 328        free(ps_matched);
 329
 330        /* "checkout -m path" to recreate conflicted state */
 331        if (opts->merge)
 332                unmerge_marked_index(&the_index);
 333
 334        /* Any unmerged paths? */
 335        for (pos = 0; pos < active_nr; pos++) {
 336                const struct cache_entry *ce = active_cache[pos];
 337                if (ce->ce_flags & CE_MATCHED) {
 338                        if (!ce_stage(ce))
 339                                continue;
 340                        if (opts->force) {
 341                                warning(_("path '%s' is unmerged"), ce->name);
 342                        } else if (opts->writeout_stage) {
 343                                errs |= check_stage(opts->writeout_stage, ce, pos);
 344                        } else if (opts->merge) {
 345                                errs |= check_stages((1<<2) | (1<<3), ce, pos);
 346                        } else {
 347                                errs = 1;
 348                                error(_("path '%s' is unmerged"), ce->name);
 349                        }
 350                        pos = skip_same_name(ce, pos) - 1;
 351                }
 352        }
 353        if (errs)
 354                return 1;
 355
 356        /* Now we are committed to check them out */
 357        state.force = 1;
 358        state.refresh_cache = 1;
 359        state.istate = &the_index;
 360
 361        enable_delayed_checkout(&state);
 362        for (pos = 0; pos < active_nr; pos++) {
 363                struct cache_entry *ce = active_cache[pos];
 364                if (ce->ce_flags & CE_MATCHED) {
 365                        if (!ce_stage(ce)) {
 366                                errs |= checkout_entry(ce, &state, NULL);
 367                                continue;
 368                        }
 369                        if (opts->writeout_stage)
 370                                errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
 371                        else if (opts->merge)
 372                                errs |= checkout_merged(pos, &state);
 373                        pos = skip_same_name(ce, pos) - 1;
 374                }
 375        }
 376        errs |= finish_delayed_checkout(&state);
 377
 378        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 379                die(_("unable to write new index file"));
 380
 381        read_ref_full("HEAD", 0, &rev, NULL);
 382        head = lookup_commit_reference_gently(the_repository, &rev, 1);
 383
 384        errs |= post_checkout_hook(head, head, 0);
 385        return errs;
 386}
 387
 388static void show_local_changes(struct object *head,
 389                               const struct diff_options *opts)
 390{
 391        struct rev_info rev;
 392        /* I think we want full paths, even if we're in a subdirectory. */
 393        init_revisions(&rev, NULL);
 394        rev.diffopt.flags = opts->flags;
 395        rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
 396        diff_setup_done(&rev.diffopt);
 397        add_pending_object(&rev, head, NULL);
 398        run_diff_index(&rev, 0);
 399}
 400
 401static void describe_detached_head(const char *msg, struct commit *commit)
 402{
 403        struct strbuf sb = STRBUF_INIT;
 404
 405        if (!parse_commit(commit))
 406                pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
 407        if (print_sha1_ellipsis()) {
 408                fprintf(stderr, "%s %s... %s\n", msg,
 409                        find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
 410        } else {
 411                fprintf(stderr, "%s %s %s\n", msg,
 412                        find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
 413        }
 414        strbuf_release(&sb);
 415}
 416
 417static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 418                      int worktree, int *writeout_error)
 419{
 420        struct unpack_trees_options opts;
 421        struct tree_desc tree_desc;
 422
 423        memset(&opts, 0, sizeof(opts));
 424        opts.head_idx = -1;
 425        opts.update = worktree;
 426        opts.skip_unmerged = !worktree;
 427        opts.reset = 1;
 428        opts.merge = 1;
 429        opts.fn = oneway_merge;
 430        opts.verbose_update = o->show_progress;
 431        opts.src_index = &the_index;
 432        opts.dst_index = &the_index;
 433        parse_tree(tree);
 434        init_tree_desc(&tree_desc, tree->buffer, tree->size);
 435        switch (unpack_trees(1, &tree_desc, &opts)) {
 436        case -2:
 437                *writeout_error = 1;
 438                /*
 439                 * We return 0 nevertheless, as the index is all right
 440                 * and more importantly we have made best efforts to
 441                 * update paths in the work tree, and we cannot revert
 442                 * them.
 443                 */
 444                /* fallthrough */
 445        case 0:
 446                return 0;
 447        default:
 448                return 128;
 449        }
 450}
 451
 452struct branch_info {
 453        const char *name; /* The short name used */
 454        const char *path; /* The full name of a real branch */
 455        struct commit *commit; /* The named commit */
 456        /*
 457         * if not null the branch is detached because it's already
 458         * checked out in this checkout
 459         */
 460        char *checkout;
 461};
 462
 463static void setup_branch_path(struct branch_info *branch)
 464{
 465        struct strbuf buf = STRBUF_INIT;
 466
 467        strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
 468        if (strcmp(buf.buf, branch->name))
 469                branch->name = xstrdup(buf.buf);
 470        strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
 471        branch->path = strbuf_detach(&buf, NULL);
 472}
 473
 474static int merge_working_tree(const struct checkout_opts *opts,
 475                              struct branch_info *old_branch_info,
 476                              struct branch_info *new_branch_info,
 477                              int *writeout_error)
 478{
 479        int ret;
 480        struct lock_file lock_file = LOCK_INIT;
 481
 482        hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 483        if (read_cache_preload(NULL) < 0)
 484                return error(_("index file corrupt"));
 485
 486        resolve_undo_clear();
 487        if (opts->force) {
 488                ret = reset_tree(get_commit_tree(new_branch_info->commit),
 489                                 opts, 1, writeout_error);
 490                if (ret)
 491                        return ret;
 492        } else {
 493                struct tree_desc trees[2];
 494                struct tree *tree;
 495                struct unpack_trees_options topts;
 496
 497                memset(&topts, 0, sizeof(topts));
 498                topts.head_idx = -1;
 499                topts.src_index = &the_index;
 500                topts.dst_index = &the_index;
 501
 502                setup_unpack_trees_porcelain(&topts, "checkout");
 503
 504                refresh_cache(REFRESH_QUIET);
 505
 506                if (unmerged_cache()) {
 507                        error(_("you need to resolve your current index first"));
 508                        return 1;
 509                }
 510
 511                /* 2-way merge to the new branch */
 512                topts.initial_checkout = is_cache_unborn();
 513                topts.update = 1;
 514                topts.merge = 1;
 515                topts.gently = opts->merge && old_branch_info->commit;
 516                topts.verbose_update = opts->show_progress;
 517                topts.fn = twoway_merge;
 518                if (opts->overwrite_ignore) {
 519                        topts.dir = xcalloc(1, sizeof(*topts.dir));
 520                        topts.dir->flags |= DIR_SHOW_IGNORED;
 521                        setup_standard_excludes(topts.dir);
 522                }
 523                tree = parse_tree_indirect(old_branch_info->commit ?
 524                                           &old_branch_info->commit->object.oid :
 525                                           the_hash_algo->empty_tree);
 526                init_tree_desc(&trees[0], tree->buffer, tree->size);
 527                tree = parse_tree_indirect(&new_branch_info->commit->object.oid);
 528                init_tree_desc(&trees[1], tree->buffer, tree->size);
 529
 530                ret = unpack_trees(2, trees, &topts);
 531                clear_unpack_trees_porcelain(&topts);
 532                if (ret == -1) {
 533                        /*
 534                         * Unpack couldn't do a trivial merge; either
 535                         * give up or do a real merge, depending on
 536                         * whether the merge flag was used.
 537                         */
 538                        struct tree *result;
 539                        struct tree *work;
 540                        struct merge_options o;
 541                        if (!opts->merge)
 542                                return 1;
 543
 544                        /*
 545                         * Without old_branch_info->commit, the below is the same as
 546                         * the two-tree unpack we already tried and failed.
 547                         */
 548                        if (!old_branch_info->commit)
 549                                return 1;
 550
 551                        /* Do more real merge */
 552
 553                        /*
 554                         * We update the index fully, then write the
 555                         * tree from the index, then merge the new
 556                         * branch with the current tree, with the old
 557                         * branch as the base. Then we reset the index
 558                         * (but not the working tree) to the new
 559                         * branch, leaving the working tree as the
 560                         * merged version, but skipping unmerged
 561                         * entries in the index.
 562                         */
 563
 564                        add_files_to_cache(NULL, NULL, 0);
 565                        /*
 566                         * NEEDSWORK: carrying over local changes
 567                         * when branches have different end-of-line
 568                         * normalization (or clean+smudge rules) is
 569                         * a pain; plumb in an option to set
 570                         * o.renormalize?
 571                         */
 572                        init_merge_options(&o);
 573                        o.verbosity = 0;
 574                        work = write_tree_from_memory(&o);
 575
 576                        ret = reset_tree(get_commit_tree(new_branch_info->commit),
 577                                         opts, 1,
 578                                         writeout_error);
 579                        if (ret)
 580                                return ret;
 581                        o.ancestor = old_branch_info->name;
 582                        o.branch1 = new_branch_info->name;
 583                        o.branch2 = "local";
 584                        ret = merge_trees(&o,
 585                                          get_commit_tree(new_branch_info->commit),
 586                                          work,
 587                                          get_commit_tree(old_branch_info->commit),
 588                                          &result);
 589                        if (ret < 0)
 590                                exit(128);
 591                        ret = reset_tree(get_commit_tree(new_branch_info->commit),
 592                                         opts, 0,
 593                                         writeout_error);
 594                        strbuf_release(&o.obuf);
 595                        if (ret)
 596                                return ret;
 597                }
 598        }
 599
 600        if (!active_cache_tree)
 601                active_cache_tree = cache_tree();
 602
 603        if (!cache_tree_fully_valid(active_cache_tree))
 604                cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
 605
 606        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 607                die(_("unable to write new index file"));
 608
 609        if (!opts->force && !opts->quiet)
 610                show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
 611
 612        return 0;
 613}
 614
 615static void report_tracking(struct branch_info *new_branch_info)
 616{
 617        struct strbuf sb = STRBUF_INIT;
 618        struct branch *branch = branch_get(new_branch_info->name);
 619
 620        if (!format_tracking_info(branch, &sb, AHEAD_BEHIND_FULL))
 621                return;
 622        fputs(sb.buf, stdout);
 623        strbuf_release(&sb);
 624}
 625
 626static void update_refs_for_switch(const struct checkout_opts *opts,
 627                                   struct branch_info *old_branch_info,
 628                                   struct branch_info *new_branch_info)
 629{
 630        struct strbuf msg = STRBUF_INIT;
 631        const char *old_desc, *reflog_msg;
 632        if (opts->new_branch) {
 633                if (opts->new_orphan_branch) {
 634                        char *refname;
 635
 636                        refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
 637                        if (opts->new_branch_log &&
 638                            !should_autocreate_reflog(refname)) {
 639                                int ret;
 640                                struct strbuf err = STRBUF_INIT;
 641
 642                                ret = safe_create_reflog(refname, 1, &err);
 643                                if (ret) {
 644                                        fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
 645                                                opts->new_orphan_branch, err.buf);
 646                                        strbuf_release(&err);
 647                                        free(refname);
 648                                        return;
 649                                }
 650                                strbuf_release(&err);
 651                        }
 652                        free(refname);
 653                }
 654                else
 655                        create_branch(opts->new_branch, new_branch_info->name,
 656                                      opts->new_branch_force ? 1 : 0,
 657                                      opts->new_branch_force ? 1 : 0,
 658                                      opts->new_branch_log,
 659                                      opts->quiet,
 660                                      opts->track);
 661                new_branch_info->name = opts->new_branch;
 662                setup_branch_path(new_branch_info);
 663        }
 664
 665        old_desc = old_branch_info->name;
 666        if (!old_desc && old_branch_info->commit)
 667                old_desc = oid_to_hex(&old_branch_info->commit->object.oid);
 668
 669        reflog_msg = getenv("GIT_REFLOG_ACTION");
 670        if (!reflog_msg)
 671                strbuf_addf(&msg, "checkout: moving from %s to %s",
 672                        old_desc ? old_desc : "(invalid)", new_branch_info->name);
 673        else
 674                strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
 675
 676        if (!strcmp(new_branch_info->name, "HEAD") && !new_branch_info->path && !opts->force_detach) {
 677                /* Nothing to do. */
 678        } else if (opts->force_detach || !new_branch_info->path) {      /* No longer on any branch. */
 679                update_ref(msg.buf, "HEAD", &new_branch_info->commit->object.oid, NULL,
 680                           REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
 681                if (!opts->quiet) {
 682                        if (old_branch_info->path &&
 683                            advice_detached_head && !opts->force_detach)
 684                                detach_advice(new_branch_info->name);
 685                        describe_detached_head(_("HEAD is now at"), new_branch_info->commit);
 686                }
 687        } else if (new_branch_info->path) {     /* Switch branches. */
 688                if (create_symref("HEAD", new_branch_info->path, msg.buf) < 0)
 689                        die(_("unable to update HEAD"));
 690                if (!opts->quiet) {
 691                        if (old_branch_info->path && !strcmp(new_branch_info->path, old_branch_info->path)) {
 692                                if (opts->new_branch_force)
 693                                        fprintf(stderr, _("Reset branch '%s'\n"),
 694                                                new_branch_info->name);
 695                                else
 696                                        fprintf(stderr, _("Already on '%s'\n"),
 697                                                new_branch_info->name);
 698                        } else if (opts->new_branch) {
 699                                if (opts->branch_exists)
 700                                        fprintf(stderr, _("Switched to and reset branch '%s'\n"), new_branch_info->name);
 701                                else
 702                                        fprintf(stderr, _("Switched to a new branch '%s'\n"), new_branch_info->name);
 703                        } else {
 704                                fprintf(stderr, _("Switched to branch '%s'\n"),
 705                                        new_branch_info->name);
 706                        }
 707                }
 708                if (old_branch_info->path && old_branch_info->name) {
 709                        if (!ref_exists(old_branch_info->path) && reflog_exists(old_branch_info->path))
 710                                delete_reflog(old_branch_info->path);
 711                }
 712        }
 713        remove_branch_state();
 714        strbuf_release(&msg);
 715        if (!opts->quiet &&
 716            (new_branch_info->path || (!opts->force_detach && !strcmp(new_branch_info->name, "HEAD"))))
 717                report_tracking(new_branch_info);
 718}
 719
 720static int add_pending_uninteresting_ref(const char *refname,
 721                                         const struct object_id *oid,
 722                                         int flags, void *cb_data)
 723{
 724        add_pending_oid(cb_data, refname, oid, UNINTERESTING);
 725        return 0;
 726}
 727
 728static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
 729{
 730        strbuf_addstr(sb, "  ");
 731        strbuf_add_unique_abbrev(sb, &commit->object.oid, DEFAULT_ABBREV);
 732        strbuf_addch(sb, ' ');
 733        if (!parse_commit(commit))
 734                pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
 735        strbuf_addch(sb, '\n');
 736}
 737
 738#define ORPHAN_CUTOFF 4
 739static void suggest_reattach(struct commit *commit, struct rev_info *revs)
 740{
 741        struct commit *c, *last = NULL;
 742        struct strbuf sb = STRBUF_INIT;
 743        int lost = 0;
 744        while ((c = get_revision(revs)) != NULL) {
 745                if (lost < ORPHAN_CUTOFF)
 746                        describe_one_orphan(&sb, c);
 747                last = c;
 748                lost++;
 749        }
 750        if (ORPHAN_CUTOFF < lost) {
 751                int more = lost - ORPHAN_CUTOFF;
 752                if (more == 1)
 753                        describe_one_orphan(&sb, last);
 754                else
 755                        strbuf_addf(&sb, _(" ... and %d more.\n"), more);
 756        }
 757
 758        fprintf(stderr,
 759                Q_(
 760                /* The singular version */
 761                "Warning: you are leaving %d commit behind, "
 762                "not connected to\n"
 763                "any of your branches:\n\n"
 764                "%s\n",
 765                /* The plural version */
 766                "Warning: you are leaving %d commits behind, "
 767                "not connected to\n"
 768                "any of your branches:\n\n"
 769                "%s\n",
 770                /* Give ngettext() the count */
 771                lost),
 772                lost,
 773                sb.buf);
 774        strbuf_release(&sb);
 775
 776        if (advice_detached_head)
 777                fprintf(stderr,
 778                        Q_(
 779                        /* The singular version */
 780                        "If you want to keep it by creating a new branch, "
 781                        "this may be a good time\nto do so with:\n\n"
 782                        " git branch <new-branch-name> %s\n\n",
 783                        /* The plural version */
 784                        "If you want to keep them by creating a new branch, "
 785                        "this may be a good time\nto do so with:\n\n"
 786                        " git branch <new-branch-name> %s\n\n",
 787                        /* Give ngettext() the count */
 788                        lost),
 789                        find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
 790}
 791
 792/*
 793 * We are about to leave commit that was at the tip of a detached
 794 * HEAD.  If it is not reachable from any ref, this is the last chance
 795 * for the user to do so without resorting to reflog.
 796 */
 797static void orphaned_commit_warning(struct commit *old_commit, struct commit *new_commit)
 798{
 799        struct rev_info revs;
 800        struct object *object = &old_commit->object;
 801
 802        init_revisions(&revs, NULL);
 803        setup_revisions(0, NULL, &revs, NULL);
 804
 805        object->flags &= ~UNINTERESTING;
 806        add_pending_object(&revs, object, oid_to_hex(&object->oid));
 807
 808        for_each_ref(add_pending_uninteresting_ref, &revs);
 809        add_pending_oid(&revs, "HEAD", &new_commit->object.oid, UNINTERESTING);
 810
 811        if (prepare_revision_walk(&revs))
 812                die(_("internal error in revision walk"));
 813        if (!(old_commit->object.flags & UNINTERESTING))
 814                suggest_reattach(old_commit, &revs);
 815        else
 816                describe_detached_head(_("Previous HEAD position was"), old_commit);
 817
 818        /* Clean up objects used, as they will be reused. */
 819        clear_commit_marks_all(ALL_REV_FLAGS);
 820}
 821
 822static int switch_branches(const struct checkout_opts *opts,
 823                           struct branch_info *new_branch_info)
 824{
 825        int ret = 0;
 826        struct branch_info old_branch_info;
 827        void *path_to_free;
 828        struct object_id rev;
 829        int flag, writeout_error = 0;
 830        memset(&old_branch_info, 0, sizeof(old_branch_info));
 831        old_branch_info.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
 832        if (old_branch_info.path)
 833                old_branch_info.commit = lookup_commit_reference_gently(the_repository, &rev, 1);
 834        if (!(flag & REF_ISSYMREF))
 835                old_branch_info.path = NULL;
 836
 837        if (old_branch_info.path)
 838                skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name);
 839
 840        if (!new_branch_info->name) {
 841                new_branch_info->name = "HEAD";
 842                new_branch_info->commit = old_branch_info.commit;
 843                if (!new_branch_info->commit)
 844                        die(_("You are on a branch yet to be born"));
 845                parse_commit_or_die(new_branch_info->commit);
 846        }
 847
 848        ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
 849        if (ret) {
 850                free(path_to_free);
 851                return ret;
 852        }
 853
 854        if (!opts->quiet && !old_branch_info.path && old_branch_info.commit && new_branch_info->commit != old_branch_info.commit)
 855                orphaned_commit_warning(old_branch_info.commit, new_branch_info->commit);
 856
 857        update_refs_for_switch(opts, &old_branch_info, new_branch_info);
 858
 859        ret = post_checkout_hook(old_branch_info.commit, new_branch_info->commit, 1);
 860        free(path_to_free);
 861        return ret || writeout_error;
 862}
 863
 864static int git_checkout_config(const char *var, const char *value, void *cb)
 865{
 866        if (!strcmp(var, "diff.ignoresubmodules")) {
 867                struct checkout_opts *opts = cb;
 868                handle_ignore_submodules_arg(&opts->diff_options, value);
 869                return 0;
 870        }
 871
 872        if (starts_with(var, "submodule."))
 873                return git_default_submodule_config(var, value, NULL);
 874
 875        return git_xmerge_config(var, value, NULL);
 876}
 877
 878static int parse_branchname_arg(int argc, const char **argv,
 879                                int dwim_new_local_branch_ok,
 880                                struct branch_info *new_branch_info,
 881                                struct checkout_opts *opts,
 882                                struct object_id *rev)
 883{
 884        struct tree **source_tree = &opts->source_tree;
 885        const char **new_branch = &opts->new_branch;
 886        int argcount = 0;
 887        struct object_id branch_rev;
 888        const char *arg;
 889        int dash_dash_pos;
 890        int has_dash_dash = 0;
 891        int i;
 892
 893        /*
 894         * case 1: git checkout <ref> -- [<paths>]
 895         *
 896         *   <ref> must be a valid tree, everything after the '--' must be
 897         *   a path.
 898         *
 899         * case 2: git checkout -- [<paths>]
 900         *
 901         *   everything after the '--' must be paths.
 902         *
 903         * case 3: git checkout <something> [--]
 904         *
 905         *   (a) If <something> is a commit, that is to
 906         *       switch to the branch or detach HEAD at it.  As a special case,
 907         *       if <something> is A...B (missing A or B means HEAD but you can
 908         *       omit at most one side), and if there is a unique merge base
 909         *       between A and B, A...B names that merge base.
 910         *
 911         *   (b) If <something> is _not_ a commit, either "--" is present
 912         *       or <something> is not a path, no -t or -b was given, and
 913         *       and there is a tracking branch whose name is <something>
 914         *       in one and only one remote, then this is a short-hand to
 915         *       fork local <something> from that remote-tracking branch.
 916         *
 917         *   (c) Otherwise, if "--" is present, treat it like case (1).
 918         *
 919         *   (d) Otherwise :
 920         *       - if it's a reference, treat it like case (1)
 921         *       - else if it's a path, treat it like case (2)
 922         *       - else: fail.
 923         *
 924         * case 4: git checkout <something> <paths>
 925         *
 926         *   The first argument must not be ambiguous.
 927         *   - If it's *only* a reference, treat it like case (1).
 928         *   - If it's only a path, treat it like case (2).
 929         *   - else: fail.
 930         *
 931         */
 932        if (!argc)
 933                return 0;
 934
 935        arg = argv[0];
 936        dash_dash_pos = -1;
 937        for (i = 0; i < argc; i++) {
 938                if (!strcmp(argv[i], "--")) {
 939                        dash_dash_pos = i;
 940                        break;
 941                }
 942        }
 943        if (dash_dash_pos == 0)
 944                return 1; /* case (2) */
 945        else if (dash_dash_pos == 1)
 946                has_dash_dash = 1; /* case (3) or (1) */
 947        else if (dash_dash_pos >= 2)
 948                die(_("only one reference expected, %d given."), dash_dash_pos);
 949
 950        if (!strcmp(arg, "-"))
 951                arg = "@{-1}";
 952
 953        if (get_oid_mb(arg, rev)) {
 954                /*
 955                 * Either case (3) or (4), with <something> not being
 956                 * a commit, or an attempt to use case (1) with an
 957                 * invalid ref.
 958                 *
 959                 * It's likely an error, but we need to find out if
 960                 * we should auto-create the branch, case (3).(b).
 961                 */
 962                int recover_with_dwim = dwim_new_local_branch_ok;
 963
 964                if (!has_dash_dash &&
 965                    (check_filename(opts->prefix, arg) || !no_wildcard(arg)))
 966                        recover_with_dwim = 0;
 967                /*
 968                 * Accept "git checkout foo" and "git checkout foo --"
 969                 * as candidates for dwim.
 970                 */
 971                if (!(argc == 1 && !has_dash_dash) &&
 972                    !(argc == 2 && has_dash_dash))
 973                        recover_with_dwim = 0;
 974
 975                if (recover_with_dwim) {
 976                        const char *remote = unique_tracking_name(arg, rev);
 977                        if (remote) {
 978                                *new_branch = arg;
 979                                arg = remote;
 980                                /* DWIMmed to create local branch, case (3).(b) */
 981                        } else {
 982                                recover_with_dwim = 0;
 983                        }
 984                }
 985
 986                if (!recover_with_dwim) {
 987                        if (has_dash_dash)
 988                                die(_("invalid reference: %s"), arg);
 989                        return argcount;
 990                }
 991        }
 992
 993        /* we can't end up being in (2) anymore, eat the argument */
 994        argcount++;
 995        argv++;
 996        argc--;
 997
 998        new_branch_info->name = arg;
 999        setup_branch_path(new_branch_info);
1000
1001        if (!check_refname_format(new_branch_info->path, 0) &&
1002            !read_ref(new_branch_info->path, &branch_rev))
1003                oidcpy(rev, &branch_rev);
1004        else
1005                new_branch_info->path = NULL; /* not an existing branch */
1006
1007        new_branch_info->commit = lookup_commit_reference_gently(the_repository, rev, 1);
1008        if (!new_branch_info->commit) {
1009                /* not a commit */
1010                *source_tree = parse_tree_indirect(rev);
1011        } else {
1012                parse_commit_or_die(new_branch_info->commit);
1013                *source_tree = get_commit_tree(new_branch_info->commit);
1014        }
1015
1016        if (!*source_tree)                   /* case (1): want a tree */
1017                die(_("reference is not a tree: %s"), arg);
1018        if (!has_dash_dash) {   /* case (3).(d) -> (1) */
1019                /*
1020                 * Do not complain the most common case
1021                 *      git checkout branch
1022                 * even if there happen to be a file called 'branch';
1023                 * it would be extremely annoying.
1024                 */
1025                if (argc)
1026                        verify_non_filename(opts->prefix, arg);
1027        } else {
1028                argcount++;
1029                argv++;
1030                argc--;
1031        }
1032
1033        return argcount;
1034}
1035
1036static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1037{
1038        int status;
1039        struct strbuf branch_ref = STRBUF_INIT;
1040
1041        if (!opts->new_branch)
1042                die(_("You are on a branch yet to be born"));
1043        strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1044        status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1045        strbuf_release(&branch_ref);
1046        if (!opts->quiet)
1047                fprintf(stderr, _("Switched to a new branch '%s'\n"),
1048                        opts->new_branch);
1049        return status;
1050}
1051
1052static int checkout_branch(struct checkout_opts *opts,
1053                           struct branch_info *new_branch_info)
1054{
1055        if (opts->pathspec.nr)
1056                die(_("paths cannot be used with switching branches"));
1057
1058        if (opts->patch_mode)
1059                die(_("'%s' cannot be used with switching branches"),
1060                    "--patch");
1061
1062        if (opts->writeout_stage)
1063                die(_("'%s' cannot be used with switching branches"),
1064                    "--ours/--theirs");
1065
1066        if (opts->force && opts->merge)
1067                die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1068
1069        if (opts->force_detach && opts->new_branch)
1070                die(_("'%s' cannot be used with '%s'"),
1071                    "--detach", "-b/-B/--orphan");
1072
1073        if (opts->new_orphan_branch) {
1074                if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1075                        die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1076        } else if (opts->force_detach) {
1077                if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1078                        die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1079        } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1080                opts->track = git_branch_track;
1081
1082        if (new_branch_info->name && !new_branch_info->commit)
1083                die(_("Cannot switch branch to a non-commit '%s'"),
1084                    new_branch_info->name);
1085
1086        if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
1087            !opts->ignore_other_worktrees) {
1088                int flag;
1089                char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
1090                if (head_ref &&
1091                    (!(flag & REF_ISSYMREF) || strcmp(head_ref, new_branch_info->path)))
1092                        die_if_checked_out(new_branch_info->path, 1);
1093                free(head_ref);
1094        }
1095
1096        if (!new_branch_info->commit && opts->new_branch) {
1097                struct object_id rev;
1098                int flag;
1099
1100                if (!read_ref_full("HEAD", 0, &rev, &flag) &&
1101                    (flag & REF_ISSYMREF) && is_null_oid(&rev))
1102                        return switch_unborn_to_new_branch(opts);
1103        }
1104        return switch_branches(opts, new_branch_info);
1105}
1106
1107int cmd_checkout(int argc, const char **argv, const char *prefix)
1108{
1109        struct checkout_opts opts;
1110        struct branch_info new_branch_info;
1111        char *conflict_style = NULL;
1112        int dwim_new_local_branch = 1;
1113        struct option options[] = {
1114                OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1115                OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1116                           N_("create and checkout a new branch")),
1117                OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1118                           N_("create/reset and checkout a branch")),
1119                OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1120                OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1121                OPT_SET_INT('t', "track",  &opts.track, N_("set upstream info for new branch"),
1122                        BRANCH_TRACK_EXPLICIT),
1123                OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1124                OPT_SET_INT_F('2', "ours", &opts.writeout_stage,
1125                              N_("checkout our version for unmerged files"),
1126                              2, PARSE_OPT_NONEG),
1127                OPT_SET_INT_F('3', "theirs", &opts.writeout_stage,
1128                              N_("checkout their version for unmerged files"),
1129                              3, PARSE_OPT_NONEG),
1130                OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)"),
1131                           PARSE_OPT_NOCOMPLETE),
1132                OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1133                OPT_BOOL_F(0, "overwrite-ignore", &opts.overwrite_ignore,
1134                           N_("update ignored files (default)"),
1135                           PARSE_OPT_NOCOMPLETE),
1136                OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1137                           N_("conflict style (merge or diff3)")),
1138                OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1139                OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1140                         N_("do not limit pathspecs to sparse entries only")),
1141                OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1142                                N_("second guess 'git checkout <no-such-branch>'")),
1143                OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1144                         N_("do not check if another worktree is holding the given ref")),
1145                { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
1146                            "checkout", "control recursive updating of submodules",
1147                            PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
1148                OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1149                OPT_END(),
1150        };
1151
1152        memset(&opts, 0, sizeof(opts));
1153        memset(&new_branch_info, 0, sizeof(new_branch_info));
1154        opts.overwrite_ignore = 1;
1155        opts.prefix = prefix;
1156        opts.show_progress = -1;
1157
1158        git_config(git_checkout_config, &opts);
1159
1160        opts.track = BRANCH_TRACK_UNSPECIFIED;
1161
1162        argc = parse_options(argc, argv, prefix, options, checkout_usage,
1163                             PARSE_OPT_KEEP_DASHDASH);
1164
1165        if (opts.show_progress < 0) {
1166                if (opts.quiet)
1167                        opts.show_progress = 0;
1168                else
1169                        opts.show_progress = isatty(2);
1170        }
1171
1172        if (conflict_style) {
1173                opts.merge = 1; /* implied */
1174                git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1175        }
1176
1177        if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1178                die(_("-b, -B and --orphan are mutually exclusive"));
1179
1180        /*
1181         * From here on, new_branch will contain the branch to be checked out,
1182         * and new_branch_force and new_orphan_branch will tell us which one of
1183         * -b/-B/--orphan is being used.
1184         */
1185        if (opts.new_branch_force)
1186                opts.new_branch = opts.new_branch_force;
1187
1188        if (opts.new_orphan_branch)
1189                opts.new_branch = opts.new_orphan_branch;
1190
1191        /* --track without -b/-B/--orphan should DWIM */
1192        if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1193                const char *argv0 = argv[0];
1194                if (!argc || !strcmp(argv0, "--"))
1195                        die (_("--track needs a branch name"));
1196                skip_prefix(argv0, "refs/", &argv0);
1197                skip_prefix(argv0, "remotes/", &argv0);
1198                argv0 = strchr(argv0, '/');
1199                if (!argv0 || !argv0[1])
1200                        die (_("Missing branch name; try -b"));
1201                opts.new_branch = argv0 + 1;
1202        }
1203
1204        /*
1205         * Extract branch name from command line arguments, so
1206         * all that is left is pathspecs.
1207         *
1208         * Handle
1209         *
1210         *  1) git checkout <tree> -- [<paths>]
1211         *  2) git checkout -- [<paths>]
1212         *  3) git checkout <something> [<paths>]
1213         *
1214         * including "last branch" syntax and DWIM-ery for names of
1215         * remote branches, erroring out for invalid or ambiguous cases.
1216         */
1217        if (argc) {
1218                struct object_id rev;
1219                int dwim_ok =
1220                        !opts.patch_mode &&
1221                        dwim_new_local_branch &&
1222                        opts.track == BRANCH_TRACK_UNSPECIFIED &&
1223                        !opts.new_branch;
1224                int n = parse_branchname_arg(argc, argv, dwim_ok,
1225                                             &new_branch_info, &opts, &rev);
1226                argv += n;
1227                argc -= n;
1228        }
1229
1230        if (argc) {
1231                parse_pathspec(&opts.pathspec, 0,
1232                               opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1233                               prefix, argv);
1234
1235                if (!opts.pathspec.nr)
1236                        die(_("invalid path specification"));
1237
1238                /*
1239                 * Try to give more helpful suggestion.
1240                 * new_branch && argc > 1 will be caught later.
1241                 */
1242                if (opts.new_branch && argc == 1)
1243                        die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1244                                argv[0], opts.new_branch);
1245
1246                if (opts.force_detach)
1247                        die(_("git checkout: --detach does not take a path argument '%s'"),
1248                            argv[0]);
1249
1250                if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1251                        die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1252                              "checking out of the index."));
1253        }
1254
1255        if (opts.new_branch) {
1256                struct strbuf buf = STRBUF_INIT;
1257
1258                if (opts.new_branch_force)
1259                        opts.branch_exists = validate_branchname(opts.new_branch, &buf);
1260                else
1261                        opts.branch_exists =
1262                                validate_new_branchname(opts.new_branch, &buf, 0);
1263                strbuf_release(&buf);
1264        }
1265
1266        UNLEAK(opts);
1267        if (opts.patch_mode || opts.pathspec.nr)
1268                return checkout_paths(&opts, new_branch_info.name);
1269        else
1270                return checkout_branch(&opts, &new_branch_info);
1271}