builtin / checkout.con commit Merge branch 'sl/clean-d-ignored-fix' into maint (f4683b4)
   1#include "builtin.h"
   2#include "lockfile.h"
   3#include "parse-options.h"
   4#include "refs.h"
   5#include "commit.h"
   6#include "tree.h"
   7#include "tree-walk.h"
   8#include "cache-tree.h"
   9#include "unpack-trees.h"
  10#include "dir.h"
  11#include "run-command.h"
  12#include "merge-recursive.h"
  13#include "branch.h"
  14#include "diff.h"
  15#include "revision.h"
  16#include "remote.h"
  17#include "blob.h"
  18#include "xdiff-interface.h"
  19#include "ll-merge.h"
  20#include "resolve-undo.h"
  21#include "submodule-config.h"
  22#include "submodule.h"
  23
  24static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
  25
  26static const char * const checkout_usage[] = {
  27        N_("git checkout [<options>] <branch>"),
  28        N_("git checkout [<options>] [<branch>] -- <file>..."),
  29        NULL,
  30};
  31
  32static int option_parse_recurse_submodules(const struct option *opt,
  33                                           const char *arg, int unset)
  34{
  35        if (unset) {
  36                recurse_submodules = RECURSE_SUBMODULES_OFF;
  37                return 0;
  38        }
  39        if (arg)
  40                recurse_submodules =
  41                        parse_update_recurse_submodules_arg(opt->long_name,
  42                                                            arg);
  43        else
  44                recurse_submodules = RECURSE_SUBMODULES_ON;
  45
  46        return 0;
  47}
  48
  49struct checkout_opts {
  50        int patch_mode;
  51        int quiet;
  52        int merge;
  53        int force;
  54        int force_detach;
  55        int writeout_stage;
  56        int overwrite_ignore;
  57        int ignore_skipworktree;
  58        int ignore_other_worktrees;
  59        int show_progress;
  60
  61        const char *new_branch;
  62        const char *new_branch_force;
  63        const char *new_orphan_branch;
  64        int new_branch_log;
  65        enum branch_track track;
  66        struct diff_options diff_options;
  67
  68        int branch_exists;
  69        const char *prefix;
  70        struct pathspec pathspec;
  71        struct tree *source_tree;
  72};
  73
  74static int post_checkout_hook(struct commit *old, struct commit *new,
  75                              int changed)
  76{
  77        return run_hook_le(NULL, "post-checkout",
  78                           oid_to_hex(old ? &old->object.oid : &null_oid),
  79                           oid_to_hex(new ? &new->object.oid : &null_oid),
  80                           changed ? "1" : "0", NULL);
  81        /* "new" can be NULL when checking out from the index before
  82           a commit exists. */
  83
  84}
  85
  86static int update_some(const unsigned char *sha1, struct strbuf *base,
  87                const char *pathname, unsigned mode, int stage, void *context)
  88{
  89        int len;
  90        struct cache_entry *ce;
  91        int pos;
  92
  93        if (S_ISDIR(mode))
  94                return READ_TREE_RECURSIVE;
  95
  96        len = base->len + strlen(pathname);
  97        ce = xcalloc(1, cache_entry_size(len));
  98        hashcpy(ce->oid.hash, sha1);
  99        memcpy(ce->name, base->buf, base->len);
 100        memcpy(ce->name + base->len, pathname, len - base->len);
 101        ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
 102        ce->ce_namelen = len;
 103        ce->ce_mode = create_ce_mode(mode);
 104
 105        /*
 106         * If the entry is the same as the current index, we can leave the old
 107         * entry in place. Whether it is UPTODATE or not, checkout_entry will
 108         * do the right thing.
 109         */
 110        pos = cache_name_pos(ce->name, ce->ce_namelen);
 111        if (pos >= 0) {
 112                struct cache_entry *old = active_cache[pos];
 113                if (ce->ce_mode == old->ce_mode &&
 114                    !oidcmp(&ce->oid, &old->oid)) {
 115                        old->ce_flags |= CE_UPDATE;
 116                        free(ce);
 117                        return 0;
 118                }
 119        }
 120
 121        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
 122        return 0;
 123}
 124
 125static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
 126{
 127        read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
 128
 129        /* update the index with the given tree's info
 130         * for all args, expanding wildcards, and exit
 131         * with any non-zero return code.
 132         */
 133        return 0;
 134}
 135
 136static int skip_same_name(const struct cache_entry *ce, int pos)
 137{
 138        while (++pos < active_nr &&
 139               !strcmp(active_cache[pos]->name, ce->name))
 140                ; /* skip */
 141        return pos;
 142}
 143
 144static int check_stage(int stage, const struct cache_entry *ce, int pos)
 145{
 146        while (pos < active_nr &&
 147               !strcmp(active_cache[pos]->name, ce->name)) {
 148                if (ce_stage(active_cache[pos]) == stage)
 149                        return 0;
 150                pos++;
 151        }
 152        if (stage == 2)
 153                return error(_("path '%s' does not have our version"), ce->name);
 154        else
 155                return error(_("path '%s' does not have their version"), ce->name);
 156}
 157
 158static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
 159{
 160        unsigned seen = 0;
 161        const char *name = ce->name;
 162
 163        while (pos < active_nr) {
 164                ce = active_cache[pos];
 165                if (strcmp(name, ce->name))
 166                        break;
 167                seen |= (1 << ce_stage(ce));
 168                pos++;
 169        }
 170        if ((stages & seen) != stages)
 171                return error(_("path '%s' does not have all necessary versions"),
 172                             name);
 173        return 0;
 174}
 175
 176static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
 177                          const struct checkout *state)
 178{
 179        while (pos < active_nr &&
 180               !strcmp(active_cache[pos]->name, ce->name)) {
 181                if (ce_stage(active_cache[pos]) == stage)
 182                        return checkout_entry(active_cache[pos], state, NULL);
 183                pos++;
 184        }
 185        if (stage == 2)
 186                return error(_("path '%s' does not have our version"), ce->name);
 187        else
 188                return error(_("path '%s' does not have their version"), ce->name);
 189}
 190
 191static int checkout_merged(int pos, const struct checkout *state)
 192{
 193        struct cache_entry *ce = active_cache[pos];
 194        const char *path = ce->name;
 195        mmfile_t ancestor, ours, theirs;
 196        int status;
 197        struct object_id oid;
 198        mmbuffer_t result_buf;
 199        struct object_id threeway[3];
 200        unsigned mode = 0;
 201
 202        memset(threeway, 0, sizeof(threeway));
 203        while (pos < active_nr) {
 204                int stage;
 205                stage = ce_stage(ce);
 206                if (!stage || strcmp(path, ce->name))
 207                        break;
 208                oidcpy(&threeway[stage - 1], &ce->oid);
 209                if (stage == 2)
 210                        mode = create_ce_mode(ce->ce_mode);
 211                pos++;
 212                ce = active_cache[pos];
 213        }
 214        if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
 215                return error(_("path '%s' does not have necessary versions"), path);
 216
 217        read_mmblob(&ancestor, &threeway[0]);
 218        read_mmblob(&ours, &threeway[1]);
 219        read_mmblob(&theirs, &threeway[2]);
 220
 221        /*
 222         * NEEDSWORK: re-create conflicts from merges with
 223         * merge.renormalize set, too
 224         */
 225        status = ll_merge(&result_buf, path, &ancestor, "base",
 226                          &ours, "ours", &theirs, "theirs", NULL);
 227        free(ancestor.ptr);
 228        free(ours.ptr);
 229        free(theirs.ptr);
 230        if (status < 0 || !result_buf.ptr) {
 231                free(result_buf.ptr);
 232                return error(_("path '%s': cannot merge"), path);
 233        }
 234
 235        /*
 236         * NEEDSWORK:
 237         * There is absolutely no reason to write this as a blob object
 238         * and create a phony cache entry.  This hack is primarily to get
 239         * to the write_entry() machinery that massages the contents to
 240         * work-tree format and writes out which only allows it for a
 241         * cache entry.  The code in write_entry() needs to be refactored
 242         * to allow us to feed a <buffer, size, mode> instead of a cache
 243         * entry.  Such a refactoring would help merge_recursive as well
 244         * (it also writes the merge result to the object database even
 245         * when it may contain conflicts).
 246         */
 247        if (write_sha1_file(result_buf.ptr, result_buf.size,
 248                            blob_type, oid.hash))
 249                die(_("Unable to add merge result for '%s'"), path);
 250        free(result_buf.ptr);
 251        ce = make_cache_entry(mode, oid.hash, path, 2, 0);
 252        if (!ce)
 253                die(_("make_cache_entry failed for path '%s'"), path);
 254        status = checkout_entry(ce, state, NULL);
 255        free(ce);
 256        return status;
 257}
 258
 259static int checkout_paths(const struct checkout_opts *opts,
 260                          const char *revision)
 261{
 262        int pos;
 263        struct checkout state = CHECKOUT_INIT;
 264        static char *ps_matched;
 265        struct object_id rev;
 266        struct commit *head;
 267        int errs = 0;
 268        struct lock_file *lock_file;
 269
 270        if (opts->track != BRANCH_TRACK_UNSPECIFIED)
 271                die(_("'%s' cannot be used with updating paths"), "--track");
 272
 273        if (opts->new_branch_log)
 274                die(_("'%s' cannot be used with updating paths"), "-l");
 275
 276        if (opts->force && opts->patch_mode)
 277                die(_("'%s' cannot be used with updating paths"), "-f");
 278
 279        if (opts->force_detach)
 280                die(_("'%s' cannot be used with updating paths"), "--detach");
 281
 282        if (opts->merge && opts->patch_mode)
 283                die(_("'%s' cannot be used with %s"), "--merge", "--patch");
 284
 285        if (opts->force && opts->merge)
 286                die(_("'%s' cannot be used with %s"), "-f", "-m");
 287
 288        if (opts->new_branch)
 289                die(_("Cannot update paths and switch to branch '%s' at the same time."),
 290                    opts->new_branch);
 291
 292        if (opts->patch_mode)
 293                return run_add_interactive(revision, "--patch=checkout",
 294                                           &opts->pathspec);
 295
 296        lock_file = xcalloc(1, sizeof(struct lock_file));
 297
 298        hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
 299        if (read_cache_preload(&opts->pathspec) < 0)
 300                return error(_("index file corrupt"));
 301
 302        if (opts->source_tree)
 303                read_tree_some(opts->source_tree, &opts->pathspec);
 304
 305        ps_matched = xcalloc(opts->pathspec.nr, 1);
 306
 307        /*
 308         * Make sure all pathspecs participated in locating the paths
 309         * to be checked out.
 310         */
 311        for (pos = 0; pos < active_nr; pos++) {
 312                struct cache_entry *ce = active_cache[pos];
 313                ce->ce_flags &= ~CE_MATCHED;
 314                if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
 315                        continue;
 316                if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
 317                        /*
 318                         * "git checkout tree-ish -- path", but this entry
 319                         * is in the original index; it will not be checked
 320                         * out to the working tree and it does not matter
 321                         * if pathspec matched this entry.  We will not do
 322                         * anything to this entry at all.
 323                         */
 324                        continue;
 325                /*
 326                 * Either this entry came from the tree-ish we are
 327                 * checking the paths out of, or we are checking out
 328                 * of the index.
 329                 *
 330                 * If it comes from the tree-ish, we already know it
 331                 * matches the pathspec and could just stamp
 332                 * CE_MATCHED to it from update_some(). But we still
 333                 * need ps_matched and read_tree_recursive (and
 334                 * eventually tree_entry_interesting) cannot fill
 335                 * ps_matched yet. Once it can, we can avoid calling
 336                 * match_pathspec() for _all_ entries when
 337                 * opts->source_tree != NULL.
 338                 */
 339                if (ce_path_match(ce, &opts->pathspec, ps_matched))
 340                        ce->ce_flags |= CE_MATCHED;
 341        }
 342
 343        if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
 344                free(ps_matched);
 345                return 1;
 346        }
 347        free(ps_matched);
 348
 349        /* "checkout -m path" to recreate conflicted state */
 350        if (opts->merge)
 351                unmerge_marked_index(&the_index);
 352
 353        /* Any unmerged paths? */
 354        for (pos = 0; pos < active_nr; pos++) {
 355                const struct cache_entry *ce = active_cache[pos];
 356                if (ce->ce_flags & CE_MATCHED) {
 357                        if (!ce_stage(ce))
 358                                continue;
 359                        if (opts->force) {
 360                                warning(_("path '%s' is unmerged"), ce->name);
 361                        } else if (opts->writeout_stage) {
 362                                errs |= check_stage(opts->writeout_stage, ce, pos);
 363                        } else if (opts->merge) {
 364                                errs |= check_stages((1<<2) | (1<<3), ce, pos);
 365                        } else {
 366                                errs = 1;
 367                                error(_("path '%s' is unmerged"), ce->name);
 368                        }
 369                        pos = skip_same_name(ce, pos) - 1;
 370                }
 371        }
 372        if (errs)
 373                return 1;
 374
 375        /* Now we are committed to check them out */
 376        state.force = 1;
 377        state.refresh_cache = 1;
 378        state.istate = &the_index;
 379        for (pos = 0; pos < active_nr; pos++) {
 380                struct cache_entry *ce = active_cache[pos];
 381                if (ce->ce_flags & CE_MATCHED) {
 382                        if (!ce_stage(ce)) {
 383                                errs |= checkout_entry(ce, &state, NULL);
 384                                continue;
 385                        }
 386                        if (opts->writeout_stage)
 387                                errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
 388                        else if (opts->merge)
 389                                errs |= checkout_merged(pos, &state);
 390                        pos = skip_same_name(ce, pos) - 1;
 391                }
 392        }
 393
 394        if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 395                die(_("unable to write new index file"));
 396
 397        read_ref_full("HEAD", 0, rev.hash, NULL);
 398        head = lookup_commit_reference_gently(rev.hash, 1);
 399
 400        errs |= post_checkout_hook(head, head, 0);
 401        return errs;
 402}
 403
 404static void show_local_changes(struct object *head,
 405                               const struct diff_options *opts)
 406{
 407        struct rev_info rev;
 408        /* I think we want full paths, even if we're in a subdirectory. */
 409        init_revisions(&rev, NULL);
 410        rev.diffopt.flags = opts->flags;
 411        rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
 412        diff_setup_done(&rev.diffopt);
 413        add_pending_object(&rev, head, NULL);
 414        run_diff_index(&rev, 0);
 415}
 416
 417static void describe_detached_head(const char *msg, struct commit *commit)
 418{
 419        struct strbuf sb = STRBUF_INIT;
 420        if (!parse_commit(commit))
 421                pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
 422        fprintf(stderr, "%s %s... %s\n", msg,
 423                find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
 424        strbuf_release(&sb);
 425}
 426
 427static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 428                      int worktree, int *writeout_error)
 429{
 430        struct unpack_trees_options opts;
 431        struct tree_desc tree_desc;
 432
 433        memset(&opts, 0, sizeof(opts));
 434        opts.head_idx = -1;
 435        opts.update = worktree;
 436        opts.skip_unmerged = !worktree;
 437        opts.reset = 1;
 438        opts.merge = 1;
 439        opts.fn = oneway_merge;
 440        opts.verbose_update = o->show_progress;
 441        opts.src_index = &the_index;
 442        opts.dst_index = &the_index;
 443        parse_tree(tree);
 444        init_tree_desc(&tree_desc, tree->buffer, tree->size);
 445        switch (unpack_trees(1, &tree_desc, &opts)) {
 446        case -2:
 447                *writeout_error = 1;
 448                /*
 449                 * We return 0 nevertheless, as the index is all right
 450                 * and more importantly we have made best efforts to
 451                 * update paths in the work tree, and we cannot revert
 452                 * them.
 453                 */
 454        case 0:
 455                return 0;
 456        default:
 457                return 128;
 458        }
 459}
 460
 461struct branch_info {
 462        const char *name; /* The short name used */
 463        const char *path; /* The full name of a real branch */
 464        struct commit *commit; /* The named commit */
 465        /*
 466         * if not null the branch is detached because it's already
 467         * checked out in this checkout
 468         */
 469        char *checkout;
 470};
 471
 472static void setup_branch_path(struct branch_info *branch)
 473{
 474        struct strbuf buf = STRBUF_INIT;
 475
 476        strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
 477        if (strcmp(buf.buf, branch->name))
 478                branch->name = xstrdup(buf.buf);
 479        strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
 480        branch->path = strbuf_detach(&buf, NULL);
 481}
 482
 483static int merge_working_tree(const struct checkout_opts *opts,
 484                              struct branch_info *old,
 485                              struct branch_info *new,
 486                              int *writeout_error)
 487{
 488        int ret;
 489        struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 490
 491        hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
 492        if (read_cache_preload(NULL) < 0)
 493                return error(_("index file corrupt"));
 494
 495        resolve_undo_clear();
 496        if (opts->force) {
 497                ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
 498                if (ret)
 499                        return ret;
 500        } else {
 501                struct tree_desc trees[2];
 502                struct tree *tree;
 503                struct unpack_trees_options topts;
 504
 505                memset(&topts, 0, sizeof(topts));
 506                topts.head_idx = -1;
 507                topts.src_index = &the_index;
 508                topts.dst_index = &the_index;
 509
 510                setup_unpack_trees_porcelain(&topts, "checkout");
 511
 512                refresh_cache(REFRESH_QUIET);
 513
 514                if (unmerged_cache()) {
 515                        error(_("you need to resolve your current index first"));
 516                        return 1;
 517                }
 518
 519                /* 2-way merge to the new branch */
 520                topts.initial_checkout = is_cache_unborn();
 521                topts.update = 1;
 522                topts.merge = 1;
 523                topts.gently = opts->merge && old->commit;
 524                topts.verbose_update = opts->show_progress;
 525                topts.fn = twoway_merge;
 526                if (opts->overwrite_ignore) {
 527                        topts.dir = xcalloc(1, sizeof(*topts.dir));
 528                        topts.dir->flags |= DIR_SHOW_IGNORED;
 529                        setup_standard_excludes(topts.dir);
 530                }
 531                tree = parse_tree_indirect(old->commit ?
 532                                           old->commit->object.oid.hash :
 533                                           EMPTY_TREE_SHA1_BIN);
 534                init_tree_desc(&trees[0], tree->buffer, tree->size);
 535                tree = parse_tree_indirect(new->commit->object.oid.hash);
 536                init_tree_desc(&trees[1], tree->buffer, tree->size);
 537
 538                ret = unpack_trees(2, trees, &topts);
 539                if (ret == -1) {
 540                        /*
 541                         * Unpack couldn't do a trivial merge; either
 542                         * give up or do a real merge, depending on
 543                         * whether the merge flag was used.
 544                         */
 545                        struct tree *result;
 546                        struct tree *work;
 547                        struct merge_options o;
 548                        if (!opts->merge)
 549                                return 1;
 550
 551                        /*
 552                         * Without old->commit, the below is the same as
 553                         * the two-tree unpack we already tried and failed.
 554                         */
 555                        if (!old->commit)
 556                                return 1;
 557
 558                        /* Do more real merge */
 559
 560                        /*
 561                         * We update the index fully, then write the
 562                         * tree from the index, then merge the new
 563                         * branch with the current tree, with the old
 564                         * branch as the base. Then we reset the index
 565                         * (but not the working tree) to the new
 566                         * branch, leaving the working tree as the
 567                         * merged version, but skipping unmerged
 568                         * entries in the index.
 569                         */
 570
 571                        add_files_to_cache(NULL, NULL, 0);
 572                        /*
 573                         * NEEDSWORK: carrying over local changes
 574                         * when branches have different end-of-line
 575                         * normalization (or clean+smudge rules) is
 576                         * a pain; plumb in an option to set
 577                         * o.renormalize?
 578                         */
 579                        init_merge_options(&o);
 580                        o.verbosity = 0;
 581                        work = write_tree_from_memory(&o);
 582
 583                        ret = reset_tree(new->commit->tree, opts, 1,
 584                                         writeout_error);
 585                        if (ret)
 586                                return ret;
 587                        o.ancestor = old->name;
 588                        o.branch1 = new->name;
 589                        o.branch2 = "local";
 590                        ret = merge_trees(&o, new->commit->tree, work,
 591                                old->commit->tree, &result);
 592                        if (ret < 0)
 593                                exit(128);
 594                        ret = reset_tree(new->commit->tree, opts, 0,
 595                                         writeout_error);
 596                        strbuf_release(&o.obuf);
 597                        if (ret)
 598                                return ret;
 599                }
 600        }
 601
 602        if (!active_cache_tree)
 603                active_cache_tree = cache_tree();
 604
 605        if (!cache_tree_fully_valid(active_cache_tree))
 606                cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
 607
 608        if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 609                die(_("unable to write new index file"));
 610
 611        if (!opts->force && !opts->quiet)
 612                show_local_changes(&new->commit->object, &opts->diff_options);
 613
 614        return 0;
 615}
 616
 617static void report_tracking(struct branch_info *new)
 618{
 619        struct strbuf sb = STRBUF_INIT;
 620        struct branch *branch = branch_get(new->name);
 621
 622        if (!format_tracking_info(branch, &sb))
 623                return;
 624        fputs(sb.buf, stdout);
 625        strbuf_release(&sb);
 626}
 627
 628static void update_refs_for_switch(const struct checkout_opts *opts,
 629                                   struct branch_info *old,
 630                                   struct branch_info *new)
 631{
 632        struct strbuf msg = STRBUF_INIT;
 633        const char *old_desc, *reflog_msg;
 634        if (opts->new_branch) {
 635                if (opts->new_orphan_branch) {
 636                        char *refname;
 637
 638                        refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
 639                        if (opts->new_branch_log &&
 640                            !should_autocreate_reflog(refname)) {
 641                                int ret;
 642                                struct strbuf err = STRBUF_INIT;
 643
 644                                ret = safe_create_reflog(refname, 1, &err);
 645                                if (ret) {
 646                                        fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
 647                                                opts->new_orphan_branch, err.buf);
 648                                        strbuf_release(&err);
 649                                        free(refname);
 650                                        return;
 651                                }
 652                                strbuf_release(&err);
 653                        }
 654                        free(refname);
 655                }
 656                else
 657                        create_branch(opts->new_branch, new->name,
 658                                      opts->new_branch_force ? 1 : 0,
 659                                      opts->new_branch_log,
 660                                      opts->new_branch_force ? 1 : 0,
 661                                      opts->quiet,
 662                                      opts->track);
 663                new->name = opts->new_branch;
 664                setup_branch_path(new);
 665        }
 666
 667        old_desc = old->name;
 668        if (!old_desc && old->commit)
 669                old_desc = oid_to_hex(&old->commit->object.oid);
 670
 671        reflog_msg = getenv("GIT_REFLOG_ACTION");
 672        if (!reflog_msg)
 673                strbuf_addf(&msg, "checkout: moving from %s to %s",
 674                        old_desc ? old_desc : "(invalid)", new->name);
 675        else
 676                strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
 677
 678        if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
 679                /* Nothing to do. */
 680        } else if (opts->force_detach || !new->path) {  /* No longer on any branch. */
 681                update_ref(msg.buf, "HEAD", new->commit->object.oid.hash, NULL,
 682                           REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 683                if (!opts->quiet) {
 684                        if (old->path &&
 685                            advice_detached_head && !opts->force_detach)
 686                                detach_advice(new->name);
 687                        describe_detached_head(_("HEAD is now at"), new->commit);
 688                }
 689        } else if (new->path) { /* Switch branches. */
 690                if (create_symref("HEAD", new->path, msg.buf) < 0)
 691                        die(_("unable to update HEAD"));
 692                if (!opts->quiet) {
 693                        if (old->path && !strcmp(new->path, old->path)) {
 694                                if (opts->new_branch_force)
 695                                        fprintf(stderr, _("Reset branch '%s'\n"),
 696                                                new->name);
 697                                else
 698                                        fprintf(stderr, _("Already on '%s'\n"),
 699                                                new->name);
 700                        } else if (opts->new_branch) {
 701                                if (opts->branch_exists)
 702                                        fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
 703                                else
 704                                        fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
 705                        } else {
 706                                fprintf(stderr, _("Switched to branch '%s'\n"),
 707                                        new->name);
 708                        }
 709                }
 710                if (old->path && old->name) {
 711                        if (!ref_exists(old->path) && reflog_exists(old->path))
 712                                delete_reflog(old->path);
 713                }
 714        }
 715        remove_branch_state();
 716        strbuf_release(&msg);
 717        if (!opts->quiet &&
 718            (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
 719                report_tracking(new);
 720}
 721
 722static int add_pending_uninteresting_ref(const char *refname,
 723                                         const struct object_id *oid,
 724                                         int flags, void *cb_data)
 725{
 726        add_pending_sha1(cb_data, refname, oid->hash, UNINTERESTING);
 727        return 0;
 728}
 729
 730static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
 731{
 732        strbuf_addstr(sb, "  ");
 733        strbuf_add_unique_abbrev(sb, commit->object.oid.hash, DEFAULT_ABBREV);
 734        strbuf_addch(sb, ' ');
 735        if (!parse_commit(commit))
 736                pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
 737        strbuf_addch(sb, '\n');
 738}
 739
 740#define ORPHAN_CUTOFF 4
 741static void suggest_reattach(struct commit *commit, struct rev_info *revs)
 742{
 743        struct commit *c, *last = NULL;
 744        struct strbuf sb = STRBUF_INIT;
 745        int lost = 0;
 746        while ((c = get_revision(revs)) != NULL) {
 747                if (lost < ORPHAN_CUTOFF)
 748                        describe_one_orphan(&sb, c);
 749                last = c;
 750                lost++;
 751        }
 752        if (ORPHAN_CUTOFF < lost) {
 753                int more = lost - ORPHAN_CUTOFF;
 754                if (more == 1)
 755                        describe_one_orphan(&sb, last);
 756                else
 757                        strbuf_addf(&sb, _(" ... and %d more.\n"), more);
 758        }
 759
 760        fprintf(stderr,
 761                Q_(
 762                /* The singular version */
 763                "Warning: you are leaving %d commit behind, "
 764                "not connected to\n"
 765                "any of your branches:\n\n"
 766                "%s\n",
 767                /* The plural version */
 768                "Warning: you are leaving %d commits behind, "
 769                "not connected to\n"
 770                "any of your branches:\n\n"
 771                "%s\n",
 772                /* Give ngettext() the count */
 773                lost),
 774                lost,
 775                sb.buf);
 776        strbuf_release(&sb);
 777
 778        if (advice_detached_head)
 779                fprintf(stderr,
 780                        Q_(
 781                        /* The singular version */
 782                        "If you want to keep it by creating a new branch, "
 783                        "this may be a good time\nto do so with:\n\n"
 784                        " git branch <new-branch-name> %s\n\n",
 785                        /* The plural version */
 786                        "If you want to keep them by creating a new branch, "
 787                        "this may be a good time\nto do so with:\n\n"
 788                        " git branch <new-branch-name> %s\n\n",
 789                        /* Give ngettext() the count */
 790                        lost),
 791                        find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
 792}
 793
 794/*
 795 * We are about to leave commit that was at the tip of a detached
 796 * HEAD.  If it is not reachable from any ref, this is the last chance
 797 * for the user to do so without resorting to reflog.
 798 */
 799static void orphaned_commit_warning(struct commit *old, struct commit *new)
 800{
 801        struct rev_info revs;
 802        struct object *object = &old->object;
 803        struct object_array refs;
 804
 805        init_revisions(&revs, NULL);
 806        setup_revisions(0, NULL, &revs, NULL);
 807
 808        object->flags &= ~UNINTERESTING;
 809        add_pending_object(&revs, object, oid_to_hex(&object->oid));
 810
 811        for_each_ref(add_pending_uninteresting_ref, &revs);
 812        add_pending_sha1(&revs, "HEAD", new->object.oid.hash, UNINTERESTING);
 813
 814        refs = revs.pending;
 815        revs.leak_pending = 1;
 816
 817        if (prepare_revision_walk(&revs))
 818                die(_("internal error in revision walk"));
 819        if (!(old->object.flags & UNINTERESTING))
 820                suggest_reattach(old, &revs);
 821        else
 822                describe_detached_head(_("Previous HEAD position was"), old);
 823
 824        clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
 825        free(refs.objects);
 826}
 827
 828static int switch_branches(const struct checkout_opts *opts,
 829                           struct branch_info *new)
 830{
 831        int ret = 0;
 832        struct branch_info old;
 833        void *path_to_free;
 834        struct object_id rev;
 835        int flag, writeout_error = 0;
 836        memset(&old, 0, sizeof(old));
 837        old.path = path_to_free = resolve_refdup("HEAD", 0, rev.hash, &flag);
 838        if (old.path)
 839                old.commit = lookup_commit_reference_gently(rev.hash, 1);
 840        if (!(flag & REF_ISSYMREF))
 841                old.path = NULL;
 842
 843        if (old.path)
 844                skip_prefix(old.path, "refs/heads/", &old.name);
 845
 846        if (!new->name) {
 847                new->name = "HEAD";
 848                new->commit = old.commit;
 849                if (!new->commit)
 850                        die(_("You are on a branch yet to be born"));
 851                parse_commit_or_die(new->commit);
 852        }
 853
 854        ret = merge_working_tree(opts, &old, new, &writeout_error);
 855        if (ret) {
 856                free(path_to_free);
 857                return ret;
 858        }
 859
 860        if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
 861                orphaned_commit_warning(old.commit, new->commit);
 862
 863        update_refs_for_switch(opts, &old, new);
 864
 865        ret = post_checkout_hook(old.commit, new->commit, 1);
 866        free(path_to_free);
 867        return ret || writeout_error;
 868}
 869
 870static int git_checkout_config(const char *var, const char *value, void *cb)
 871{
 872        if (!strcmp(var, "diff.ignoresubmodules")) {
 873                struct checkout_opts *opts = cb;
 874                handle_ignore_submodules_arg(&opts->diff_options, value);
 875                return 0;
 876        }
 877
 878        if (starts_with(var, "submodule."))
 879                return parse_submodule_config_option(var, value);
 880
 881        return git_xmerge_config(var, value, NULL);
 882}
 883
 884struct tracking_name_data {
 885        /* const */ char *src_ref;
 886        char *dst_ref;
 887        struct object_id *dst_oid;
 888        int unique;
 889};
 890
 891static int check_tracking_name(struct remote *remote, void *cb_data)
 892{
 893        struct tracking_name_data *cb = cb_data;
 894        struct refspec query;
 895        memset(&query, 0, sizeof(struct refspec));
 896        query.src = cb->src_ref;
 897        if (remote_find_tracking(remote, &query) ||
 898            get_oid(query.dst, cb->dst_oid)) {
 899                free(query.dst);
 900                return 0;
 901        }
 902        if (cb->dst_ref) {
 903                free(query.dst);
 904                cb->unique = 0;
 905                return 0;
 906        }
 907        cb->dst_ref = query.dst;
 908        return 0;
 909}
 910
 911static const char *unique_tracking_name(const char *name, struct object_id *oid)
 912{
 913        struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
 914        cb_data.src_ref = xstrfmt("refs/heads/%s", name);
 915        cb_data.dst_oid = oid;
 916        for_each_remote(check_tracking_name, &cb_data);
 917        free(cb_data.src_ref);
 918        if (cb_data.unique)
 919                return cb_data.dst_ref;
 920        free(cb_data.dst_ref);
 921        return NULL;
 922}
 923
 924static int parse_branchname_arg(int argc, const char **argv,
 925                                int dwim_new_local_branch_ok,
 926                                struct branch_info *new,
 927                                struct checkout_opts *opts,
 928                                struct object_id *rev)
 929{
 930        struct tree **source_tree = &opts->source_tree;
 931        const char **new_branch = &opts->new_branch;
 932        int argcount = 0;
 933        struct object_id branch_rev;
 934        const char *arg;
 935        int dash_dash_pos;
 936        int has_dash_dash = 0;
 937        int i;
 938
 939        /*
 940         * case 1: git checkout <ref> -- [<paths>]
 941         *
 942         *   <ref> must be a valid tree, everything after the '--' must be
 943         *   a path.
 944         *
 945         * case 2: git checkout -- [<paths>]
 946         *
 947         *   everything after the '--' must be paths.
 948         *
 949         * case 3: git checkout <something> [--]
 950         *
 951         *   (a) If <something> is a commit, that is to
 952         *       switch to the branch or detach HEAD at it.  As a special case,
 953         *       if <something> is A...B (missing A or B means HEAD but you can
 954         *       omit at most one side), and if there is a unique merge base
 955         *       between A and B, A...B names that merge base.
 956         *
 957         *   (b) If <something> is _not_ a commit, either "--" is present
 958         *       or <something> is not a path, no -t or -b was given, and
 959         *       and there is a tracking branch whose name is <something>
 960         *       in one and only one remote, then this is a short-hand to
 961         *       fork local <something> from that remote-tracking branch.
 962         *
 963         *   (c) Otherwise, if "--" is present, treat it like case (1).
 964         *
 965         *   (d) Otherwise :
 966         *       - if it's a reference, treat it like case (1)
 967         *       - else if it's a path, treat it like case (2)
 968         *       - else: fail.
 969         *
 970         * case 4: git checkout <something> <paths>
 971         *
 972         *   The first argument must not be ambiguous.
 973         *   - If it's *only* a reference, treat it like case (1).
 974         *   - If it's only a path, treat it like case (2).
 975         *   - else: fail.
 976         *
 977         */
 978        if (!argc)
 979                return 0;
 980
 981        arg = argv[0];
 982        dash_dash_pos = -1;
 983        for (i = 0; i < argc; i++) {
 984                if (!strcmp(argv[i], "--")) {
 985                        dash_dash_pos = i;
 986                        break;
 987                }
 988        }
 989        if (dash_dash_pos == 0)
 990                return 1; /* case (2) */
 991        else if (dash_dash_pos == 1)
 992                has_dash_dash = 1; /* case (3) or (1) */
 993        else if (dash_dash_pos >= 2)
 994                die(_("only one reference expected, %d given."), dash_dash_pos);
 995
 996        if (!strcmp(arg, "-"))
 997                arg = "@{-1}";
 998
 999        if (get_oid_mb(arg, rev)) {
1000                /*
1001                 * Either case (3) or (4), with <something> not being
1002                 * a commit, or an attempt to use case (1) with an
1003                 * invalid ref.
1004                 *
1005                 * It's likely an error, but we need to find out if
1006                 * we should auto-create the branch, case (3).(b).
1007                 */
1008                int recover_with_dwim = dwim_new_local_branch_ok;
1009
1010                if (!has_dash_dash &&
1011                    (check_filename(opts->prefix, arg) || !no_wildcard(arg)))
1012                        recover_with_dwim = 0;
1013                /*
1014                 * Accept "git checkout foo" and "git checkout foo --"
1015                 * as candidates for dwim.
1016                 */
1017                if (!(argc == 1 && !has_dash_dash) &&
1018                    !(argc == 2 && has_dash_dash))
1019                        recover_with_dwim = 0;
1020
1021                if (recover_with_dwim) {
1022                        const char *remote = unique_tracking_name(arg, rev);
1023                        if (remote) {
1024                                *new_branch = arg;
1025                                arg = remote;
1026                                /* DWIMmed to create local branch, case (3).(b) */
1027                        } else {
1028                                recover_with_dwim = 0;
1029                        }
1030                }
1031
1032                if (!recover_with_dwim) {
1033                        if (has_dash_dash)
1034                                die(_("invalid reference: %s"), arg);
1035                        return argcount;
1036                }
1037        }
1038
1039        /* we can't end up being in (2) anymore, eat the argument */
1040        argcount++;
1041        argv++;
1042        argc--;
1043
1044        new->name = arg;
1045        setup_branch_path(new);
1046
1047        if (!check_refname_format(new->path, 0) &&
1048            !read_ref(new->path, branch_rev.hash))
1049                oidcpy(rev, &branch_rev);
1050        else
1051                new->path = NULL; /* not an existing branch */
1052
1053        new->commit = lookup_commit_reference_gently(rev->hash, 1);
1054        if (!new->commit) {
1055                /* not a commit */
1056                *source_tree = parse_tree_indirect(rev->hash);
1057        } else {
1058                parse_commit_or_die(new->commit);
1059                *source_tree = new->commit->tree;
1060        }
1061
1062        if (!*source_tree)                   /* case (1): want a tree */
1063                die(_("reference is not a tree: %s"), arg);
1064        if (!has_dash_dash) {   /* case (3).(d) -> (1) */
1065                /*
1066                 * Do not complain the most common case
1067                 *      git checkout branch
1068                 * even if there happen to be a file called 'branch';
1069                 * it would be extremely annoying.
1070                 */
1071                if (argc)
1072                        verify_non_filename(opts->prefix, arg);
1073        } else {
1074                argcount++;
1075                argv++;
1076                argc--;
1077        }
1078
1079        return argcount;
1080}
1081
1082static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1083{
1084        int status;
1085        struct strbuf branch_ref = STRBUF_INIT;
1086
1087        if (!opts->new_branch)
1088                die(_("You are on a branch yet to be born"));
1089        strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1090        status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1091        strbuf_release(&branch_ref);
1092        if (!opts->quiet)
1093                fprintf(stderr, _("Switched to a new branch '%s'\n"),
1094                        opts->new_branch);
1095        return status;
1096}
1097
1098static int checkout_branch(struct checkout_opts *opts,
1099                           struct branch_info *new)
1100{
1101        if (opts->pathspec.nr)
1102                die(_("paths cannot be used with switching branches"));
1103
1104        if (opts->patch_mode)
1105                die(_("'%s' cannot be used with switching branches"),
1106                    "--patch");
1107
1108        if (opts->writeout_stage)
1109                die(_("'%s' cannot be used with switching branches"),
1110                    "--ours/--theirs");
1111
1112        if (opts->force && opts->merge)
1113                die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1114
1115        if (opts->force_detach && opts->new_branch)
1116                die(_("'%s' cannot be used with '%s'"),
1117                    "--detach", "-b/-B/--orphan");
1118
1119        if (opts->new_orphan_branch) {
1120                if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1121                        die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1122        } else if (opts->force_detach) {
1123                if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1124                        die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1125        } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1126                opts->track = git_branch_track;
1127
1128        if (new->name && !new->commit)
1129                die(_("Cannot switch branch to a non-commit '%s'"),
1130                    new->name);
1131
1132        if (new->path && !opts->force_detach && !opts->new_branch &&
1133            !opts->ignore_other_worktrees) {
1134                struct object_id oid;
1135                int flag;
1136                char *head_ref = resolve_refdup("HEAD", 0, oid.hash, &flag);
1137                if (head_ref &&
1138                    (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1139                        die_if_checked_out(new->path, 1);
1140                free(head_ref);
1141        }
1142
1143        if (!new->commit && opts->new_branch) {
1144                struct object_id rev;
1145                int flag;
1146
1147                if (!read_ref_full("HEAD", 0, rev.hash, &flag) &&
1148                    (flag & REF_ISSYMREF) && is_null_oid(&rev))
1149                        return switch_unborn_to_new_branch(opts);
1150        }
1151        return switch_branches(opts, new);
1152}
1153
1154int cmd_checkout(int argc, const char **argv, const char *prefix)
1155{
1156        struct checkout_opts opts;
1157        struct branch_info new;
1158        char *conflict_style = NULL;
1159        int dwim_new_local_branch = 1;
1160        struct option options[] = {
1161                OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1162                OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1163                           N_("create and checkout a new branch")),
1164                OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1165                           N_("create/reset and checkout a branch")),
1166                OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1167                OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1168                OPT_SET_INT('t', "track",  &opts.track, N_("set upstream info for new branch"),
1169                        BRANCH_TRACK_EXPLICIT),
1170                OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1171                OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1172                            2),
1173                OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1174                            3),
1175                OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1176                OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1177                OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1178                OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1179                           N_("conflict style (merge or diff3)")),
1180                OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1181                OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1182                         N_("do not limit pathspecs to sparse entries only")),
1183                OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1184                                N_("second guess 'git checkout <no-such-branch>'")),
1185                OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1186                         N_("do not check if another worktree is holding the given ref")),
1187                { OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
1188                            "checkout", "control recursive updating of submodules",
1189                            PARSE_OPT_OPTARG, option_parse_recurse_submodules },
1190                OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1191                OPT_END(),
1192        };
1193
1194        memset(&opts, 0, sizeof(opts));
1195        memset(&new, 0, sizeof(new));
1196        opts.overwrite_ignore = 1;
1197        opts.prefix = prefix;
1198        opts.show_progress = -1;
1199
1200        gitmodules_config();
1201        git_config(git_checkout_config, &opts);
1202
1203        opts.track = BRANCH_TRACK_UNSPECIFIED;
1204
1205        argc = parse_options(argc, argv, prefix, options, checkout_usage,
1206                             PARSE_OPT_KEEP_DASHDASH);
1207
1208        if (opts.show_progress < 0) {
1209                if (opts.quiet)
1210                        opts.show_progress = 0;
1211                else
1212                        opts.show_progress = isatty(2);
1213        }
1214
1215        if (conflict_style) {
1216                opts.merge = 1; /* implied */
1217                git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1218        }
1219
1220        if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
1221                git_config(submodule_config, NULL);
1222                if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
1223                        set_config_update_recurse_submodules(recurse_submodules);
1224        }
1225
1226        if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1227                die(_("-b, -B and --orphan are mutually exclusive"));
1228
1229        /*
1230         * From here on, new_branch will contain the branch to be checked out,
1231         * and new_branch_force and new_orphan_branch will tell us which one of
1232         * -b/-B/--orphan is being used.
1233         */
1234        if (opts.new_branch_force)
1235                opts.new_branch = opts.new_branch_force;
1236
1237        if (opts.new_orphan_branch)
1238                opts.new_branch = opts.new_orphan_branch;
1239
1240        /* --track without -b/-B/--orphan should DWIM */
1241        if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1242                const char *argv0 = argv[0];
1243                if (!argc || !strcmp(argv0, "--"))
1244                        die (_("--track needs a branch name"));
1245                skip_prefix(argv0, "refs/", &argv0);
1246                skip_prefix(argv0, "remotes/", &argv0);
1247                argv0 = strchr(argv0, '/');
1248                if (!argv0 || !argv0[1])
1249                        die (_("Missing branch name; try -b"));
1250                opts.new_branch = argv0 + 1;
1251        }
1252
1253        /*
1254         * Extract branch name from command line arguments, so
1255         * all that is left is pathspecs.
1256         *
1257         * Handle
1258         *
1259         *  1) git checkout <tree> -- [<paths>]
1260         *  2) git checkout -- [<paths>]
1261         *  3) git checkout <something> [<paths>]
1262         *
1263         * including "last branch" syntax and DWIM-ery for names of
1264         * remote branches, erroring out for invalid or ambiguous cases.
1265         */
1266        if (argc) {
1267                struct object_id rev;
1268                int dwim_ok =
1269                        !opts.patch_mode &&
1270                        dwim_new_local_branch &&
1271                        opts.track == BRANCH_TRACK_UNSPECIFIED &&
1272                        !opts.new_branch;
1273                int n = parse_branchname_arg(argc, argv, dwim_ok,
1274                                             &new, &opts, &rev);
1275                argv += n;
1276                argc -= n;
1277        }
1278
1279        if (argc) {
1280                parse_pathspec(&opts.pathspec, 0,
1281                               opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1282                               prefix, argv);
1283
1284                if (!opts.pathspec.nr)
1285                        die(_("invalid path specification"));
1286
1287                /*
1288                 * Try to give more helpful suggestion.
1289                 * new_branch && argc > 1 will be caught later.
1290                 */
1291                if (opts.new_branch && argc == 1)
1292                        die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1293                                argv[0], opts.new_branch);
1294
1295                if (opts.force_detach)
1296                        die(_("git checkout: --detach does not take a path argument '%s'"),
1297                            argv[0]);
1298
1299                if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1300                        die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1301                              "checking out of the index."));
1302        }
1303
1304        if (opts.new_branch) {
1305                struct strbuf buf = STRBUF_INIT;
1306
1307                opts.branch_exists =
1308                        validate_new_branchname(opts.new_branch, &buf,
1309                                                !!opts.new_branch_force,
1310                                                !!opts.new_branch_force);
1311
1312                strbuf_release(&buf);
1313        }
1314
1315        if (opts.patch_mode || opts.pathspec.nr)
1316                return checkout_paths(&opts, new.name);
1317        else
1318                return checkout_branch(&opts, &new);
1319}