builtin/checkout.c

   1 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   2 #include "builtin.h"
   3 #include "advice.h"
   4 #include "blob.h"
   5 #include "branch.h"
   6 #include "cache-tree.h"
   7 #include "checkout.h"
   8 #include "commit.h"
   9 #include "config.h"
  10 #include "diff.h"
  11 #include "dir.h"
  12 #include "ll-merge.h"
  13 #include "lockfile.h"
  14 #include "merge-recursive.h"
  15 #include "object-store.h"
  16 #include "parse-options.h"
  17 #include "refs.h"
  18 #include "remote.h"
  19 #include "resolve-undo.h"
  20 #include "revision.h"
  21 #include "run-command.h"
  22 #include "submodule.h"
  23 #include "submodule-config.h"
  24 #include "tree.h"
  25 #include "tree-walk.h"
  26 #include "unpack-trees.h"
  27 #include "wt-status.h"
  28 #include "xdiff-interface.h"
  29
  30 static const char * const checkout_usage[] = {
  31         N_("git checkout [<options>] <branch>"),
  32         N_("git checkout [<options>] [<branch>] -- <file>..."),
  33         NULL,
  34 };
  35
  36 static const char * const switch_branch_usage[] = {
  37         N_("git switch [<options>] [<branch>]"),
  38         NULL,
  39 };
  40
  41 static const char * const restore_usage[] = {
  42         N_("git restore [<options>] [--source=<branch>] <file>..."),
  43         NULL,
  44 };
  45
  46 struct checkout_opts {
  47         int patch_mode;
  48         int quiet;
  49         int merge;
  50         int force;
  51         int force_detach;
  52         int implicit_detach;
  53         int writeout_stage;
  54         int overwrite_ignore;
  55         int ignore_skipworktree;
  56         int ignore_other_worktrees;
  57         int show_progress;
  58         int count_checkout_paths;
  59         int overlay_mode;
  60         int dwim_new_local_branch;
  61         int discard_changes;
  62         int accept_ref;
  63         int accept_pathspec;
  64         int switch_branch_doing_nothing_is_ok;
  65         int only_merge_on_switching_branches;
  66         int can_switch_when_in_progress;
  67         int orphan_from_empty_tree;
  68         int empty_pathspec_ok;
  69         int checkout_index;
  70         int checkout_worktree;
  71         const char *ignore_unmerged_opt;
  72         int ignore_unmerged;
  73         int pathspec_file_nul;
  74         const char *pathspec_from_file;
  75
  76         const char *new_branch;
  77         const char *new_branch_force;
  78         const char *new_orphan_branch;
  79         int new_branch_log;
  80         enum branch_track track;
  81         struct diff_options diff_options;
  82         char *conflict_style;
  83
  84         int branch_exists;
  85         const char *prefix;
  86         struct pathspec pathspec;
  87         const char *from_treeish;
  88         struct tree *source_tree;
  89 };
  90
  91 struct branch_info {
  92         const char *name; /* The short name used */
  93         const char *path; /* The full name of a real branch */
  94         struct commit *commit; /* The named commit */
  95         char *refname; /* The full name of the ref being checked out. */
  96         struct object_id oid; /* The object ID of the commit being checked out. */
  97         /*
  98          * if not null the branch is detached because it's already
  99          * checked out in this checkout
 100          */
 101         char *checkout;
 102 };
 103
 104 static int post_checkout_hook(struct commit *old_commit, struct commit *new_commit,
 105                               int changed)
 106 {
 107         return run_hook_le(NULL, "post-checkout",
 108                            oid_to_hex(old_commit ? &old_commit->object.oid : &null_oid),
 109                            oid_to_hex(new_commit ? &new_commit->object.oid : &null_oid),
 110                            changed ? "1" : "0", NULL);
 111         /* "new_commit" can be NULL when checking out from the index before
 112            a commit exists. */
 113
 114 }
 115
 116 static int update_some(const struct object_id *oid, struct strbuf *base,
 117                 const char *pathname, unsigned mode, int stage, void *context)
 118 {
 119         int len;
 120         struct cache_entry *ce;
 121         int pos;
 122
 123         if (S_ISDIR(mode))
 124                 return READ_TREE_RECURSIVE;
 125
 126         len = base->len + strlen(pathname);
 127         ce = make_empty_cache_entry(&the_index, len);
 128         oidcpy(&ce->oid, oid);
 129         memcpy(ce->name, base->buf, base->len);
 130         memcpy(ce->name + base->len, pathname, len - base->len);
 131         ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
 132         ce->ce_namelen = len;
 133         ce->ce_mode = create_ce_mode(mode);
 134
 135         /*
 136          * If the entry is the same as the current index, we can leave the old
 137          * entry in place. Whether it is UPTODATE or not, checkout_entry will
 138          * do the right thing.
 139          */
 140         pos = cache_name_pos(ce->name, ce->ce_namelen);
 141         if (pos >= 0) {
 142                 struct cache_entry *old = active_cache[pos];
 143                 if (ce->ce_mode == old->ce_mode &&
 144                     !ce_intent_to_add(old) &&
 145                     oideq(&ce->oid, &old->oid)) {
 146                         old->ce_flags |= CE_UPDATE;
 147                         discard_cache_entry(ce);
 148                         return 0;
 149                 }
 150         }
 151
 152         add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
 153         return 0;
 154 }
 155
 156 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
 157 {
 158         read_tree_recursive(the_repository, tree, "", 0, 0,
 159                             pathspec, update_some, NULL);
 160
 161         /* update the index with the given tree's info
 162          * for all args, expanding wildcards, and exit
 163          * with any non-zero return code.
 164          */
 165         return 0;
 166 }
 167
 168 static int skip_same_name(const struct cache_entry *ce, int pos)
 169 {
 170         while (++pos < active_nr &&
 171                !strcmp(active_cache[pos]->name, ce->name))
 172                 ; /* skip */
 173         return pos;
 174 }
 175
 176 static int check_stage(int stage, const struct cache_entry *ce, int pos,
 177                        int overlay_mode)
 178 {
 179         while (pos < active_nr &&
 180                !strcmp(active_cache[pos]->name, ce->name)) {
 181                 if (ce_stage(active_cache[pos]) == stage)
 182                         return 0;
 183                 pos++;
 184         }
 185         if (!overlay_mode)
 186                 return 0;
 187         if (stage == 2)
 188                 return error(_("path '%s' does not have our version"), ce->name);
 189         else
 190                 return error(_("path '%s' does not have their version"), ce->name);
 191 }
 192
 193 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
 194 {
 195         unsigned seen = 0;
 196         const char *name = ce->name;
 197
 198         while (pos < active_nr) {
 199                 ce = active_cache[pos];
 200                 if (strcmp(name, ce->name))
 201                         break;
 202                 seen |= (1 << ce_stage(ce));
 203                 pos++;
 204         }
 205         if ((stages & seen) != stages)
 206                 return error(_("path '%s' does not have all necessary versions"),
 207                              name);
 208         return 0;
 209 }
 210
 211 static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
 212                           const struct checkout *state, int *nr_checkouts,
 213                           int overlay_mode)
 214 {
 215         while (pos < active_nr &&
 216                !strcmp(active_cache[pos]->name, ce->name)) {
 217                 if (ce_stage(active_cache[pos]) == stage)
 218                         return checkout_entry(active_cache[pos], state,
 219                                               NULL, nr_checkouts);
 220                 pos++;
 221         }
 222         if (!overlay_mode) {
 223                 unlink_entry(ce);
 224                 return 0;
 225         }
 226         if (stage == 2)
 227                 return error(_("path '%s' does not have our version"), ce->name);
 228         else
 229                 return error(_("path '%s' does not have their version"), ce->name);
 230 }
 231
 232 static int checkout_merged(int pos, const struct checkout *state, int *nr_checkouts)
 233 {
 234         struct cache_entry *ce = active_cache[pos];
 235         const char *path = ce->name;
 236         mmfile_t ancestor, ours, theirs;
 237         int status;
 238         struct object_id oid;
 239         mmbuffer_t result_buf;
 240         struct object_id threeway[3];
 241         unsigned mode = 0;
 242
 243         memset(threeway, 0, sizeof(threeway));
 244         while (pos < active_nr) {
 245                 int stage;
 246                 stage = ce_stage(ce);
 247                 if (!stage || strcmp(path, ce->name))
 248                         break;
 249                 oidcpy(&threeway[stage - 1], &ce->oid);
 250                 if (stage == 2)
 251                         mode = create_ce_mode(ce->ce_mode);
 252                 pos++;
 253                 ce = active_cache[pos];
 254         }
 255         if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
 256                 return error(_("path '%s' does not have necessary versions"), path);
 257
 258         read_mmblob(&ancestor, &threeway[0]);
 259         read_mmblob(&ours, &threeway[1]);
 260         read_mmblob(&theirs, &threeway[2]);
 261
 262         /*
 263          * NEEDSWORK: re-create conflicts from merges with
 264          * merge.renormalize set, too
 265          */
 266         status = ll_merge(&result_buf, path, &ancestor, "base",
 267                           &ours, "ours", &theirs, "theirs",
 268                           state->istate, NULL);
 269         free(ancestor.ptr);
 270         free(ours.ptr);
 271         free(theirs.ptr);
 272         if (status < 0 || !result_buf.ptr) {
 273                 free(result_buf.ptr);
 274                 return error(_("path '%s': cannot merge"), path);
 275         }
 276
 277         /*
 278          * NEEDSWORK:
 279          * There is absolutely no reason to write this as a blob object
 280          * and create a phony cache entry.  This hack is primarily to get
 281          * to the write_entry() machinery that massages the contents to
 282          * work-tree format and writes out which only allows it for a
 283          * cache entry.  The code in write_entry() needs to be refactored
 284          * to allow us to feed a <buffer, size, mode> instead of a cache
 285          * entry.  Such a refactoring would help merge_recursive as well
 286          * (it also writes the merge result to the object database even
 287          * when it may contain conflicts).
 288          */
 289         if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
 290                 die(_("Unable to add merge result for '%s'"), path);
 291         free(result_buf.ptr);
 292         ce = make_transient_cache_entry(mode, &oid, path, 2);
 293         if (!ce)
 294                 die(_("make_cache_entry failed for path '%s'"), path);
 295         status = checkout_entry(ce, state, NULL, nr_checkouts);
 296         discard_cache_entry(ce);
 297         return status;
 298 }
 299
 300 static void mark_ce_for_checkout_overlay(struct cache_entry *ce,
 301                                          char *ps_matched,
 302                                          const struct checkout_opts *opts)
 303 {
 304         ce->ce_flags &= ~CE_MATCHED;
 305         if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
 306                 return;
 307         if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
 308                 /*
 309                  * "git checkout tree-ish -- path", but this entry
 310                  * is in the original index but is not in tree-ish
 311                  * or does not match the pathspec; it will not be
 312                  * checked out to the working tree.  We will not do
 313                  * anything to this entry at all.
 314                  */
 315                 return;
 316         /*
 317          * Either this entry came from the tree-ish we are
 318          * checking the paths out of, or we are checking out
 319          * of the index.
 320          *
 321          * If it comes from the tree-ish, we already know it
 322          * matches the pathspec and could just stamp
 323          * CE_MATCHED to it from update_some(). But we still
 324          * need ps_matched and read_tree_recursive (and
 325          * eventually tree_entry_interesting) cannot fill
 326          * ps_matched yet. Once it can, we can avoid calling
 327          * match_pathspec() for _all_ entries when
 328          * opts->source_tree != NULL.
 329          */
 330         if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched))
 331                 ce->ce_flags |= CE_MATCHED;
 332 }
 333
 334 static void mark_ce_for_checkout_no_overlay(struct cache_entry *ce,
 335                                             char *ps_matched,
 336                                             const struct checkout_opts *opts)
 337 {
 338         ce->ce_flags &= ~CE_MATCHED;
 339         if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
 340                 return;
 341         if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched)) {
 342                 ce->ce_flags |= CE_MATCHED;
 343                 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
 344                         /*
 345                          * In overlay mode, but the path is not in
 346                          * tree-ish, which means we should remove it
 347                          * from the index and the working tree.
 348                          */
 349                         ce->ce_flags |= CE_REMOVE | CE_WT_REMOVE;
 350         }
 351 }
 352
 353 static int checkout_worktree(const struct checkout_opts *opts,
 354                              const struct branch_info *info)
 355 {
 356         struct checkout state = CHECKOUT_INIT;
 357         int nr_checkouts = 0, nr_unmerged = 0;
 358         int errs = 0;
 359         int pos;
 360
 361         state.force = 1;
 362         state.refresh_cache = 1;
 363         state.istate = &the_index;
 364
 365         init_checkout_metadata(&state.meta, info->refname,
 366                                info->commit ? &info->commit->object.oid : &info->oid,
 367                                NULL);
 368
 369         enable_delayed_checkout(&state);
 370         for (pos = 0; pos < active_nr; pos++) {
 371                 struct cache_entry *ce = active_cache[pos];
 372                 if (ce->ce_flags & CE_MATCHED) {
 373                         if (!ce_stage(ce)) {
 374                                 errs |= checkout_entry(ce, &state,
 375                                                        NULL, &nr_checkouts);
 376                                 continue;
 377                         }
 378                         if (opts->writeout_stage)
 379                                 errs |= checkout_stage(opts->writeout_stage,
 380                                                        ce, pos,
 381                                                        &state,
 382                                                        &nr_checkouts, opts->overlay_mode);
 383                         else if (opts->merge)
 384                                 errs |= checkout_merged(pos, &state,
 385                                                         &nr_unmerged);
 386                         pos = skip_same_name(ce, pos) - 1;
 387                 }
 388         }
 389         remove_marked_cache_entries(&the_index, 1);
 390         remove_scheduled_dirs();
 391         errs |= finish_delayed_checkout(&state, &nr_checkouts);
 392
 393         if (opts->count_checkout_paths) {
 394                 if (nr_unmerged)
 395                         fprintf_ln(stderr, Q_("Recreated %d merge conflict",
 396                                               "Recreated %d merge conflicts",
 397                                               nr_unmerged),
 398                                    nr_unmerged);
 399                 if (opts->source_tree)
 400                         fprintf_ln(stderr, Q_("Updated %d path from %s",
 401                                               "Updated %d paths from %s",
 402                                               nr_checkouts),
 403                                    nr_checkouts,
 404                                    find_unique_abbrev(&opts->source_tree->object.oid,
 405                                                       DEFAULT_ABBREV));
 406                 else if (!nr_unmerged || nr_checkouts)
 407                         fprintf_ln(stderr, Q_("Updated %d path from the index",
 408                                               "Updated %d paths from the index",
 409                                               nr_checkouts),
 410                                    nr_checkouts);
 411         }
 412
 413         return errs;
 414 }
 415
 416 static int checkout_paths(const struct checkout_opts *opts,
 417                           const struct branch_info *new_branch_info)
 418 {
 419         int pos;
 420         static char *ps_matched;
 421         struct object_id rev;
 422         struct commit *head;
 423         int errs = 0;
 424         struct lock_file lock_file = LOCK_INIT;
 425         int checkout_index;
 426
 427         trace2_cmd_mode(opts->patch_mode ? "patch" : "path");
 428
 429         if (opts->track != BRANCH_TRACK_UNSPECIFIED)
 430                 die(_("'%s' cannot be used with updating paths"), "--track");
 431
 432         if (opts->new_branch_log)
 433                 die(_("'%s' cannot be used with updating paths"), "-l");
 434
 435         if (opts->ignore_unmerged && opts->patch_mode)
 436                 die(_("'%s' cannot be used with updating paths"),
 437                     opts->ignore_unmerged_opt);
 438
 439         if (opts->force_detach)
 440                 die(_("'%s' cannot be used with updating paths"), "--detach");
 441
 442         if (opts->merge && opts->patch_mode)
 443                 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
 444
 445         if (opts->ignore_unmerged && opts->merge)
 446                 die(_("'%s' cannot be used with %s"),
 447                     opts->ignore_unmerged_opt, "-m");
 448
 449         if (opts->new_branch)
 450                 die(_("Cannot update paths and switch to branch '%s' at the same time."),
 451                     opts->new_branch);
 452
 453         if (!opts->checkout_worktree && !opts->checkout_index)
 454                 die(_("neither '%s' or '%s' is specified"),
 455                     "--staged", "--worktree");
 456
 457         if (!opts->checkout_worktree && !opts->from_treeish)
 458                 die(_("'%s' must be used when '%s' is not specified"),
 459                     "--worktree", "--source");
 460
 461         if (opts->checkout_index && !opts->checkout_worktree &&
 462             opts->writeout_stage)
 463                 die(_("'%s' or '%s' cannot be used with %s"),
 464                     "--ours", "--theirs", "--staged");
 465
 466         if (opts->checkout_index && !opts->checkout_worktree &&
 467             opts->merge)
 468                 die(_("'%s' or '%s' cannot be used with %s"),
 469                     "--merge", "--conflict", "--staged");
 470
 471         if (opts->patch_mode) {
 472                 const char *patch_mode;
 473
 474                 if (opts->checkout_index && opts->checkout_worktree)
 475                         patch_mode = "--patch=checkout";
 476                 else if (opts->checkout_index && !opts->checkout_worktree)
 477                         patch_mode = "--patch=reset";
 478                 else if (!opts->checkout_index && opts->checkout_worktree)
 479                         patch_mode = "--patch=worktree";
 480                 else
 481                         BUG("either flag must have been set, worktree=%d, index=%d",
 482                             opts->checkout_worktree, opts->checkout_index);
 483                 return run_add_interactive(new_branch_info->name, patch_mode, &opts->pathspec);
 484         }
 485
 486         repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 487         if (read_cache_preload(&opts->pathspec) < 0)
 488                 return error(_("index file corrupt"));
 489
 490         if (opts->source_tree)
 491                 read_tree_some(opts->source_tree, &opts->pathspec);
 492
 493         ps_matched = xcalloc(opts->pathspec.nr, 1);
 494
 495         /*
 496          * Make sure all pathspecs participated in locating the paths
 497          * to be checked out.
 498          */
 499         for (pos = 0; pos < active_nr; pos++)
 500                 if (opts->overlay_mode)
 501                         mark_ce_for_checkout_overlay(active_cache[pos],
 502                                                      ps_matched,
 503                                                      opts);
 504                 else
 505                         mark_ce_for_checkout_no_overlay(active_cache[pos],
 506                                                         ps_matched,
 507                                                         opts);
 508
 509         if (report_path_error(ps_matched, &opts->pathspec)) {
 510                 free(ps_matched);
 511                 return 1;
 512         }
 513         free(ps_matched);
 514
 515         /* "checkout -m path" to recreate conflicted state */
 516         if (opts->merge)
 517                 unmerge_marked_index(&the_index);
 518
 519         /* Any unmerged paths? */
 520         for (pos = 0; pos < active_nr; pos++) {
 521                 const struct cache_entry *ce = active_cache[pos];
 522                 if (ce->ce_flags & CE_MATCHED) {
 523                         if (!ce_stage(ce))
 524                                 continue;
 525                         if (opts->ignore_unmerged) {
 526                                 if (!opts->quiet)
 527                                         warning(_("path '%s' is unmerged"), ce->name);
 528                         } else if (opts->writeout_stage) {
 529                                 errs |= check_stage(opts->writeout_stage, ce, pos, opts->overlay_mode);
 530                         } else if (opts->merge) {
 531                                 errs |= check_stages((1<<2) | (1<<3), ce, pos);
 532                         } else {
 533                                 errs = 1;
 534                                 error(_("path '%s' is unmerged"), ce->name);
 535                         }
 536                         pos = skip_same_name(ce, pos) - 1;
 537                 }
 538         }
 539         if (errs)
 540                 return 1;
 541
 542         /* Now we are committed to check them out */
 543         if (opts->checkout_worktree)
 544                 errs |= checkout_worktree(opts, new_branch_info);
 545         else
 546                 remove_marked_cache_entries(&the_index, 1);
 547
 548         /*
 549          * Allow updating the index when checking out from the index.
 550          * This is to save new stat info.
 551          */
 552         if (opts->checkout_worktree && !opts->checkout_index && !opts->source_tree)
 553                 checkout_index = 1;
 554         else
 555                 checkout_index = opts->checkout_index;
 556
 557         if (checkout_index) {
 558                 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 559                         die(_("unable to write new index file"));
 560         } else {
 561                 /*
 562                  * NEEDSWORK: if --worktree is not specified, we
 563                  * should save stat info of checked out files in the
 564                  * index to avoid the next (potentially costly)
 565                  * refresh. But it's a bit tricker to do...
 566                  */
 567                 rollback_lock_file(&lock_file);
 568         }
 569
 570         read_ref_full("HEAD", 0, &rev, NULL);
 571         head = lookup_commit_reference_gently(the_repository, &rev, 1);
 572
 573         errs |= post_checkout_hook(head, head, 0);
 574         return errs;
 575 }
 576
 577 static void show_local_changes(struct object *head,
 578                                const struct diff_options *opts)
 579 {
 580         struct rev_info rev;
 581         /* I think we want full paths, even if we're in a subdirectory. */
 582         repo_init_revisions(the_repository, &rev, NULL);
 583         rev.diffopt.flags = opts->flags;
 584         rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
 585         diff_setup_done(&rev.diffopt);
 586         add_pending_object(&rev, head, NULL);
 587         run_diff_index(&rev, 0);
 588 }
 589
 590 static void describe_detached_head(const char *msg, struct commit *commit)
 591 {
 592         struct strbuf sb = STRBUF_INIT;
 593
 594         if (!parse_commit(commit))
 595                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
 596         if (print_sha1_ellipsis()) {
 597                 fprintf(stderr, "%s %s... %s\n", msg,
 598                         find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
 599         } else {
 600                 fprintf(stderr, "%s %s %s\n", msg,
 601                         find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
 602         }
 603         strbuf_release(&sb);
 604 }
 605
 606 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 607                       int worktree, int *writeout_error,
 608                       struct branch_info *info)
 609 {
 610         struct unpack_trees_options opts;
 611         struct tree_desc tree_desc;
 612
 613         memset(&opts, 0, sizeof(opts));
 614         opts.head_idx = -1;
 615         opts.update = worktree;
 616         opts.skip_unmerged = !worktree;
 617         opts.reset = 1;
 618         opts.merge = 1;
 619         opts.fn = oneway_merge;
 620         opts.verbose_update = o->show_progress;
 621         opts.src_index = &the_index;
 622         opts.dst_index = &the_index;
 623         init_checkout_metadata(&opts.meta, info->refname,
 624                                info->commit ? &info->commit->object.oid :
 625                                is_null_oid(&info->oid) ? &tree->object.oid :
 626                                &info->oid,
 627                                NULL);
 628         parse_tree(tree);
 629         init_tree_desc(&tree_desc, tree->buffer, tree->size);
 630         switch (unpack_trees(1, &tree_desc, &opts)) {
 631         case -2:
 632                 *writeout_error = 1;
 633                 /*
 634                  * We return 0 nevertheless, as the index is all right
 635                  * and more importantly we have made best efforts to
 636                  * update paths in the work tree, and we cannot revert
 637                  * them.
 638                  */
 639                 /* fallthrough */
 640         case 0:
 641                 return 0;
 642         default:
 643                 return 128;
 644         }
 645 }
 646
 647 static void setup_branch_path(struct branch_info *branch)
 648 {
 649         struct strbuf buf = STRBUF_INIT;
 650
 651         /*
 652          * If this is a ref, resolve it; otherwise, look up the OID for our
 653          * expression.  Failure here is okay.
 654          */
 655         if (!dwim_ref(branch->name, strlen(branch->name), &branch->oid, &branch->refname))
 656                 repo_get_oid_committish(the_repository, branch->name, &branch->oid);
 657
 658         strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
 659         if (strcmp(buf.buf, branch->name))
 660                 branch->name = xstrdup(buf.buf);
 661         strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
 662         branch->path = strbuf_detach(&buf, NULL);
 663 }
 664
 665 static int merge_working_tree(const struct checkout_opts *opts,
 666                               struct branch_info *old_branch_info,
 667                               struct branch_info *new_branch_info,
 668                               int *writeout_error)
 669 {
 670         int ret;
 671         struct lock_file lock_file = LOCK_INIT;
 672         struct tree *new_tree;
 673
 674         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 675         if (read_cache_preload(NULL) < 0)
 676                 return error(_("index file corrupt"));
 677
 678         resolve_undo_clear();
 679         if (opts->new_orphan_branch && opts->orphan_from_empty_tree) {
 680                 if (new_branch_info->commit)
 681                         BUG("'switch --orphan' should never accept a commit as starting point");
 682                 new_tree = parse_tree_indirect(the_hash_algo->empty_tree);
 683         } else
 684                 new_tree = get_commit_tree(new_branch_info->commit);
 685         if (opts->discard_changes) {
 686                 ret = reset_tree(new_tree, opts, 1, writeout_error, new_branch_info);
 687                 if (ret)
 688                         return ret;
 689         } else {
 690                 struct tree_desc trees[2];
 691                 struct tree *tree;
 692                 struct unpack_trees_options topts;
 693
 694                 memset(&topts, 0, sizeof(topts));
 695                 topts.head_idx = -1;
 696                 topts.src_index = &the_index;
 697                 topts.dst_index = &the_index;
 698
 699                 setup_unpack_trees_porcelain(&topts, "checkout");
 700
 701                 refresh_cache(REFRESH_QUIET);
 702
 703                 if (unmerged_cache()) {
 704                         error(_("you need to resolve your current index first"));
 705                         return 1;
 706                 }
 707
 708                 /* 2-way merge to the new branch */
 709                 topts.initial_checkout = is_cache_unborn();
 710                 topts.update = 1;
 711                 topts.merge = 1;
 712                 topts.quiet = opts->merge && old_branch_info->commit;
 713                 topts.verbose_update = opts->show_progress;
 714                 topts.fn = twoway_merge;
 715                 init_checkout_metadata(&topts.meta, new_branch_info->refname,
 716                                        new_branch_info->commit ?
 717                                        &new_branch_info->commit->object.oid :
 718                                        &new_branch_info->oid, NULL);
 719                 if (opts->overwrite_ignore) {
 720                         topts.dir = xcalloc(1, sizeof(*topts.dir));
 721                         topts.dir->flags |= DIR_SHOW_IGNORED;
 722                         setup_standard_excludes(topts.dir);
 723                 }
 724                 tree = parse_tree_indirect(old_branch_info->commit ?
 725                                            &old_branch_info->commit->object.oid :
 726                                            the_hash_algo->empty_tree);
 727                 init_tree_desc(&trees[0], tree->buffer, tree->size);
 728                 parse_tree(new_tree);
 729                 tree = new_tree;
 730                 init_tree_desc(&trees[1], tree->buffer, tree->size);
 731
 732                 ret = unpack_trees(2, trees, &topts);
 733                 clear_unpack_trees_porcelain(&topts);
 734                 if (ret == -1) {
 735                         /*
 736                          * Unpack couldn't do a trivial merge; either
 737                          * give up or do a real merge, depending on
 738                          * whether the merge flag was used.
 739                          */
 740                         struct tree *work;
 741                         struct tree *old_tree;
 742                         struct merge_options o;
 743                         struct strbuf sb = STRBUF_INIT;
 744                         struct strbuf old_commit_shortname = STRBUF_INIT;
 745
 746                         if (!opts->merge)
 747                                 return 1;
 748
 749                         /*
 750                          * Without old_branch_info->commit, the below is the same as
 751                          * the two-tree unpack we already tried and failed.
 752                          */
 753                         if (!old_branch_info->commit)
 754                                 return 1;
 755                         old_tree = get_commit_tree(old_branch_info->commit);
 756
 757                         if (repo_index_has_changes(the_repository, old_tree, &sb))
 758                                 die(_("cannot continue with staged changes in "
 759                                       "the following files:\n%s"), sb.buf);
 760                         strbuf_release(&sb);
 761
 762                         /* Do more real merge */
 763
 764                         /*
 765                          * We update the index fully, then write the
 766                          * tree from the index, then merge the new
 767                          * branch with the current tree, with the old
 768                          * branch as the base. Then we reset the index
 769                          * (but not the working tree) to the new
 770                          * branch, leaving the working tree as the
 771                          * merged version, but skipping unmerged
 772                          * entries in the index.
 773                          */
 774
 775                         add_files_to_cache(NULL, NULL, 0);
 776                         /*
 777                          * NEEDSWORK: carrying over local changes
 778                          * when branches have different end-of-line
 779                          * normalization (or clean+smudge rules) is
 780                          * a pain; plumb in an option to set
 781                          * o.renormalize?
 782                          */
 783                         init_merge_options(&o, the_repository);
 784                         o.verbosity = 0;
 785                         work = write_in_core_index_as_tree(the_repository);
 786
 787                         ret = reset_tree(new_tree,
 788                                          opts, 1,
 789                                          writeout_error, new_branch_info);
 790                         if (ret)
 791                                 return ret;
 792                         o.ancestor = old_branch_info->name;
 793                         if (old_branch_info->name == NULL) {
 794                                 strbuf_add_unique_abbrev(&old_commit_shortname,
 795                                                          &old_branch_info->commit->object.oid,
 796                                                          DEFAULT_ABBREV);
 797                                 o.ancestor = old_commit_shortname.buf;
 798                         }
 799                         o.branch1 = new_branch_info->name;
 800                         o.branch2 = "local";
 801                         ret = merge_trees(&o,
 802                                           new_tree,
 803                                           work,
 804                                           old_tree);
 805                         if (ret < 0)
 806                                 exit(128);
 807                         ret = reset_tree(new_tree,
 808                                          opts, 0,
 809                                          writeout_error, new_branch_info);
 810                         strbuf_release(&o.obuf);
 811                         strbuf_release(&old_commit_shortname);
 812                         if (ret)
 813                                 return ret;
 814                 }
 815         }
 816
 817         if (!active_cache_tree)
 818                 active_cache_tree = cache_tree();
 819
 820         if (!cache_tree_fully_valid(active_cache_tree))
 821                 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
 822
 823         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 824                 die(_("unable to write new index file"));
 825
 826         if (!opts->discard_changes && !opts->quiet && new_branch_info->commit)
 827                 show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
 828
 829         return 0;
 830 }
 831
 832 static void report_tracking(struct branch_info *new_branch_info)
 833 {
 834         struct strbuf sb = STRBUF_INIT;
 835         struct branch *branch = branch_get(new_branch_info->name);
 836
 837         if (!format_tracking_info(branch, &sb, AHEAD_BEHIND_FULL))
 838                 return;
 839         fputs(sb.buf, stdout);
 840         strbuf_release(&sb);
 841 }
 842
 843 static void update_refs_for_switch(const struct checkout_opts *opts,
 844                                    struct branch_info *old_branch_info,
 845                                    struct branch_info *new_branch_info)
 846 {
 847         struct strbuf msg = STRBUF_INIT;
 848         const char *old_desc, *reflog_msg;
 849         if (opts->new_branch) {
 850                 if (opts->new_orphan_branch) {
 851                         char *refname;
 852
 853                         refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
 854                         if (opts->new_branch_log &&
 855                             !should_autocreate_reflog(refname)) {
 856                                 int ret;
 857                                 struct strbuf err = STRBUF_INIT;
 858
 859                                 ret = safe_create_reflog(refname, 1, &err);
 860                                 if (ret) {
 861                                         fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
 862                                                 opts->new_orphan_branch, err.buf);
 863                                         strbuf_release(&err);
 864                                         free(refname);
 865                                         return;
 866                                 }
 867                                 strbuf_release(&err);
 868                         }
 869                         free(refname);
 870                 }
 871                 else
 872                         create_branch(the_repository,
 873                                       opts->new_branch, new_branch_info->name,
 874                                       opts->new_branch_force ? 1 : 0,
 875                                       opts->new_branch_force ? 1 : 0,
 876                                       opts->new_branch_log,
 877                                       opts->quiet,
 878                                       opts->track);
 879                 new_branch_info->name = opts->new_branch;
 880                 setup_branch_path(new_branch_info);
 881         }
 882
 883         old_desc = old_branch_info->name;
 884         if (!old_desc && old_branch_info->commit)
 885                 old_desc = oid_to_hex(&old_branch_info->commit->object.oid);
 886
 887         reflog_msg = getenv("GIT_REFLOG_ACTION");
 888         if (!reflog_msg)
 889                 strbuf_addf(&msg, "checkout: moving from %s to %s",
 890                         old_desc ? old_desc : "(invalid)", new_branch_info->name);
 891         else
 892                 strbuf_insertstr(&msg, 0, reflog_msg);
 893
 894         if (!strcmp(new_branch_info->name, "HEAD") && !new_branch_info->path && !opts->force_detach) {
 895                 /* Nothing to do. */
 896         } else if (opts->force_detach || !new_branch_info->path) {      /* No longer on any branch. */
 897                 update_ref(msg.buf, "HEAD", &new_branch_info->commit->object.oid, NULL,
 898                            REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
 899                 if (!opts->quiet) {
 900                         if (old_branch_info->path &&
 901                             advice_detached_head && !opts->force_detach)
 902                                 detach_advice(new_branch_info->name);
 903                         describe_detached_head(_("HEAD is now at"), new_branch_info->commit);
 904                 }
 905         } else if (new_branch_info->path) {     /* Switch branches. */
 906                 if (create_symref("HEAD", new_branch_info->path, msg.buf) < 0)
 907                         die(_("unable to update HEAD"));
 908                 if (!opts->quiet) {
 909                         if (old_branch_info->path && !strcmp(new_branch_info->path, old_branch_info->path)) {
 910                                 if (opts->new_branch_force)
 911                                         fprintf(stderr, _("Reset branch '%s'\n"),
 912                                                 new_branch_info->name);
 913                                 else
 914                                         fprintf(stderr, _("Already on '%s'\n"),
 915                                                 new_branch_info->name);
 916                         } else if (opts->new_branch) {
 917                                 if (opts->branch_exists)
 918                                         fprintf(stderr, _("Switched to and reset branch '%s'\n"), new_branch_info->name);
 919                                 else
 920                                         fprintf(stderr, _("Switched to a new branch '%s'\n"), new_branch_info->name);
 921                         } else {
 922                                 fprintf(stderr, _("Switched to branch '%s'\n"),
 923                                         new_branch_info->name);
 924                         }
 925                 }
 926                 if (old_branch_info->path && old_branch_info->name) {
 927                         if (!ref_exists(old_branch_info->path) && reflog_exists(old_branch_info->path))
 928                                 delete_reflog(old_branch_info->path);
 929                 }
 930         }
 931         remove_branch_state(the_repository, !opts->quiet);
 932         strbuf_release(&msg);
 933         if (!opts->quiet &&
 934             (new_branch_info->path || (!opts->force_detach && !strcmp(new_branch_info->name, "HEAD"))))
 935                 report_tracking(new_branch_info);
 936 }
 937
 938 static int add_pending_uninteresting_ref(const char *refname,
 939                                          const struct object_id *oid,
 940                                          int flags, void *cb_data)
 941 {
 942         add_pending_oid(cb_data, refname, oid, UNINTERESTING);
 943         return 0;
 944 }
 945
 946 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
 947 {
 948         strbuf_addstr(sb, "  ");
 949         strbuf_add_unique_abbrev(sb, &commit->object.oid, DEFAULT_ABBREV);
 950         strbuf_addch(sb, ' ');
 951         if (!parse_commit(commit))
 952                 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
 953         strbuf_addch(sb, '\n');
 954 }
 955
 956 #define ORPHAN_CUTOFF 4
 957 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
 958 {
 959         struct commit *c, *last = NULL;
 960         struct strbuf sb = STRBUF_INIT;
 961         int lost = 0;
 962         while ((c = get_revision(revs)) != NULL) {
 963                 if (lost < ORPHAN_CUTOFF)
 964                         describe_one_orphan(&sb, c);
 965                 last = c;
 966                 lost++;
 967         }
 968         if (ORPHAN_CUTOFF < lost) {
 969                 int more = lost - ORPHAN_CUTOFF;
 970                 if (more == 1)
 971                         describe_one_orphan(&sb, last);
 972                 else
 973                         strbuf_addf(&sb, _(" ... and %d more.\n"), more);
 974         }
 975
 976         fprintf(stderr,
 977                 Q_(
 978                 /* The singular version */
 979                 "Warning: you are leaving %d commit behind, "
 980                 "not connected to\n"
 981                 "any of your branches:\n\n"
 982                 "%s\n",
 983                 /* The plural version */
 984                 "Warning: you are leaving %d commits behind, "
 985                 "not connected to\n"
 986                 "any of your branches:\n\n"
 987                 "%s\n",
 988                 /* Give ngettext() the count */
 989                 lost),
 990                 lost,
 991                 sb.buf);
 992         strbuf_release(&sb);
 993
 994         if (advice_detached_head)
 995                 fprintf(stderr,
 996                         Q_(
 997                         /* The singular version */
 998                         "If you want to keep it by creating a new branch, "
 999                         "this may be a good time\nto do so with:\n\n"
1000                         " git branch <new-branch-name> %s\n\n",
1001                         /* The plural version */
1002                         "If you want to keep them by creating a new branch, "
1003                         "this may be a good time\nto do so with:\n\n"
1004                         " git branch <new-branch-name> %s\n\n",
1005                         /* Give ngettext() the count */
1006                         lost),
1007                         find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
1008 }
1009
1010 /*
1011  * We are about to leave commit that was at the tip of a detached
1012  * HEAD.  If it is not reachable from any ref, this is the last chance
1013  * for the user to do so without resorting to reflog.
1014  */
1015 static void orphaned_commit_warning(struct commit *old_commit, struct commit *new_commit)
1016 {
1017         struct rev_info revs;
1018         struct object *object = &old_commit->object;
1019
1020         repo_init_revisions(the_repository, &revs, NULL);
1021         setup_revisions(0, NULL, &revs, NULL);
1022
1023         object->flags &= ~UNINTERESTING;
1024         add_pending_object(&revs, object, oid_to_hex(&object->oid));
1025
1026         for_each_ref(add_pending_uninteresting_ref, &revs);
1027         if (new_commit)
1028                 add_pending_oid(&revs, "HEAD",
1029                                 &new_commit->object.oid,
1030                                 UNINTERESTING);
1031
1032         if (prepare_revision_walk(&revs))
1033                 die(_("internal error in revision walk"));
1034         if (!(old_commit->object.flags & UNINTERESTING))
1035                 suggest_reattach(old_commit, &revs);
1036         else
1037                 describe_detached_head(_("Previous HEAD position was"), old_commit);
1038
1039         /* Clean up objects used, as they will be reused. */
1040         clear_commit_marks_all(ALL_REV_FLAGS);
1041 }
1042
1043 static int switch_branches(const struct checkout_opts *opts,
1044                            struct branch_info *new_branch_info)
1045 {
1046         int ret = 0;
1047         struct branch_info old_branch_info;
1048         void *path_to_free;
1049         struct object_id rev;
1050         int flag, writeout_error = 0;
1051         int do_merge = 1;
1052
1053         trace2_cmd_mode("branch");
1054
1055         memset(&old_branch_info, 0, sizeof(old_branch_info));
1056         old_branch_info.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
1057         if (old_branch_info.path)
1058                 old_branch_info.commit = lookup_commit_reference_gently(the_repository, &rev, 1);
1059         if (!(flag & REF_ISSYMREF))
1060                 old_branch_info.path = NULL;
1061
1062         if (old_branch_info.path)
1063                 skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name);
1064
1065         if (opts->new_orphan_branch && opts->orphan_from_empty_tree) {
1066                 if (new_branch_info->name)
1067                         BUG("'switch --orphan' should never accept a commit as starting point");
1068                 new_branch_info->commit = NULL;
1069                 new_branch_info->name = "(empty)";
1070                 do_merge = 1;
1071         }
1072
1073         if (!new_branch_info->name) {
1074                 new_branch_info->name = "HEAD";
1075                 new_branch_info->commit = old_branch_info.commit;
1076                 if (!new_branch_info->commit)
1077                         die(_("You are on a branch yet to be born"));
1078                 parse_commit_or_die(new_branch_info->commit);
1079
1080                 if (opts->only_merge_on_switching_branches)
1081                         do_merge = 0;
1082         }
1083
1084         if (do_merge) {
1085                 ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
1086                 if (ret) {
1087                         free(path_to_free);
1088                         return ret;
1089                 }
1090         }
1091
1092         if (!opts->quiet && !old_branch_info.path && old_branch_info.commit && new_branch_info->commit != old_branch_info.commit)
1093                 orphaned_commit_warning(old_branch_info.commit, new_branch_info->commit);
1094
1095         update_refs_for_switch(opts, &old_branch_info, new_branch_info);
1096
1097         ret = post_checkout_hook(old_branch_info.commit, new_branch_info->commit, 1);
1098         free(path_to_free);
1099         return ret || writeout_error;
1100 }
1101
1102 static int git_checkout_config(const char *var, const char *value, void *cb)
1103 {
1104         if (!strcmp(var, "diff.ignoresubmodules")) {
1105                 struct checkout_opts *opts = cb;
1106                 handle_ignore_submodules_arg(&opts->diff_options, value);
1107                 return 0;
1108         }
1109
1110         if (starts_with(var, "submodule."))
1111                 return git_default_submodule_config(var, value, NULL);
1112
1113         return git_xmerge_config(var, value, NULL);
1114 }
1115
1116 static void setup_new_branch_info_and_source_tree(
1117         struct branch_info *new_branch_info,
1118         struct checkout_opts *opts,
1119         struct object_id *rev,
1120         const char *arg)
1121 {
1122         struct tree **source_tree = &opts->source_tree;
1123         struct object_id branch_rev;
1124
1125         new_branch_info->name = arg;
1126         setup_branch_path(new_branch_info);
1127
1128         if (!check_refname_format(new_branch_info->path, 0) &&
1129             !read_ref(new_branch_info->path, &branch_rev))
1130                 oidcpy(rev, &branch_rev);
1131         else
1132                 new_branch_info->path = NULL; /* not an existing branch */
1133
1134         new_branch_info->commit = lookup_commit_reference_gently(the_repository, rev, 1);
1135         if (!new_branch_info->commit) {
1136                 /* not a commit */
1137                 *source_tree = parse_tree_indirect(rev);
1138         } else {
1139                 parse_commit_or_die(new_branch_info->commit);
1140                 *source_tree = get_commit_tree(new_branch_info->commit);
1141         }
1142 }
1143
1144 static const char *parse_remote_branch(const char *arg,
1145                                        struct object_id *rev,
1146                                        int could_be_checkout_paths)
1147 {
1148         int num_matches = 0;
1149         const char *remote = unique_tracking_name(arg, rev, &num_matches);
1150
1151         if (remote && could_be_checkout_paths) {
1152                 die(_("'%s' could be both a local file and a tracking branch.\n"
1153                         "Please use -- (and optionally --no-guess) to disambiguate"),
1154                     arg);
1155         }
1156
1157         if (!remote && num_matches > 1) {
1158             if (advice_checkout_ambiguous_remote_branch_name) {
1159                     advise(_("If you meant to check out a remote tracking branch on, e.g. 'origin',\n"
1160                              "you can do so by fully qualifying the name with the --track option:\n"
1161                              "\n"
1162                              "    git checkout --track origin/<name>\n"
1163                              "\n"
1164                              "If you'd like to always have checkouts of an ambiguous <name> prefer\n"
1165                              "one remote, e.g. the 'origin' remote, consider setting\n"
1166                              "checkout.defaultRemote=origin in your config."));
1167             }
1168
1169             die(_("'%s' matched multiple (%d) remote tracking branches"),
1170                 arg, num_matches);
1171         }
1172
1173         return remote;
1174 }
1175
1176 static int parse_branchname_arg(int argc, const char **argv,
1177                                 int dwim_new_local_branch_ok,
1178                                 struct branch_info *new_branch_info,
1179                                 struct checkout_opts *opts,
1180                                 struct object_id *rev)
1181 {
1182         const char **new_branch = &opts->new_branch;
1183         int argcount = 0;
1184         const char *arg;
1185         int dash_dash_pos;
1186         int has_dash_dash = 0;
1187         int i;
1188
1189         /*
1190          * case 1: git checkout <ref> -- [<paths>]
1191          *
1192          *   <ref> must be a valid tree, everything after the '--' must be
1193          *   a path.
1194          *
1195          * case 2: git checkout -- [<paths>]
1196          *
1197          *   everything after the '--' must be paths.
1198          *
1199          * case 3: git checkout <something> [--]
1200          *
1201          *   (a) If <something> is a commit, that is to
1202          *       switch to the branch or detach HEAD at it.  As a special case,
1203          *       if <something> is A...B (missing A or B means HEAD but you can
1204          *       omit at most one side), and if there is a unique merge base
1205          *       between A and B, A...B names that merge base.
1206          *
1207          *   (b) If <something> is _not_ a commit, either "--" is present
1208          *       or <something> is not a path, no -t or -b was given, and
1209          *       and there is a tracking branch whose name is <something>
1210          *       in one and only one remote (or if the branch exists on the
1211          *       remote named in checkout.defaultRemote), then this is a
1212          *       short-hand to fork local <something> from that
1213          *       remote-tracking branch.
1214          *
1215          *   (c) Otherwise, if "--" is present, treat it like case (1).
1216          *
1217          *   (d) Otherwise :
1218          *       - if it's a reference, treat it like case (1)
1219          *       - else if it's a path, treat it like case (2)
1220          *       - else: fail.
1221          *
1222          * case 4: git checkout <something> <paths>
1223          *
1224          *   The first argument must not be ambiguous.
1225          *   - If it's *only* a reference, treat it like case (1).
1226          *   - If it's only a path, treat it like case (2).
1227          *   - else: fail.
1228          *
1229          */
1230         if (!argc)
1231                 return 0;
1232
1233         if (!opts->accept_pathspec) {
1234                 if (argc > 1)
1235                         die(_("only one reference expected"));
1236                 has_dash_dash = 1; /* helps disambiguate */
1237         }
1238
1239         arg = argv[0];
1240         dash_dash_pos = -1;
1241         for (i = 0; i < argc; i++) {
1242                 if (opts->accept_pathspec && !strcmp(argv[i], "--")) {
1243                         dash_dash_pos = i;
1244                         break;
1245                 }
1246         }
1247         if (dash_dash_pos == 0)
1248                 return 1; /* case (2) */
1249         else if (dash_dash_pos == 1)
1250                 has_dash_dash = 1; /* case (3) or (1) */
1251         else if (dash_dash_pos >= 2)
1252                 die(_("only one reference expected, %d given."), dash_dash_pos);
1253         opts->count_checkout_paths = !opts->quiet && !has_dash_dash;
1254
1255         if (!strcmp(arg, "-"))
1256                 arg = "@{-1}";
1257
1258         if (get_oid_mb(arg, rev)) {
1259                 /*
1260                  * Either case (3) or (4), with <something> not being
1261                  * a commit, or an attempt to use case (1) with an
1262                  * invalid ref.
1263                  *
1264                  * It's likely an error, but we need to find out if
1265                  * we should auto-create the branch, case (3).(b).
1266                  */
1267                 int recover_with_dwim = dwim_new_local_branch_ok;
1268
1269                 int could_be_checkout_paths = !has_dash_dash &&
1270                         check_filename(opts->prefix, arg);
1271
1272                 if (!has_dash_dash && !no_wildcard(arg))
1273                         recover_with_dwim = 0;
1274
1275                 /*
1276                  * Accept "git checkout foo", "git checkout foo --"
1277                  * and "git switch foo" as candidates for dwim.
1278                  */
1279                 if (!(argc == 1 && !has_dash_dash) &&
1280                     !(argc == 2 && has_dash_dash) &&
1281                     opts->accept_pathspec)
1282                         recover_with_dwim = 0;
1283
1284                 if (recover_with_dwim) {
1285                         const char *remote = parse_remote_branch(arg, rev,
1286                                                                  could_be_checkout_paths);
1287                         if (remote) {
1288                                 *new_branch = arg;
1289                                 arg = remote;
1290                                 /* DWIMmed to create local branch, case (3).(b) */
1291                         } else {
1292                                 recover_with_dwim = 0;
1293                         }
1294                 }
1295
1296                 if (!recover_with_dwim) {
1297                         if (has_dash_dash)
1298                                 die(_("invalid reference: %s"), arg);
1299                         return argcount;
1300                 }
1301         }
1302
1303         /* we can't end up being in (2) anymore, eat the argument */
1304         argcount++;
1305         argv++;
1306         argc--;
1307
1308         setup_new_branch_info_and_source_tree(new_branch_info, opts, rev, arg);
1309
1310         if (!opts->source_tree)                   /* case (1): want a tree */
1311                 die(_("reference is not a tree: %s"), arg);
1312
1313         if (!has_dash_dash) {   /* case (3).(d) -> (1) */
1314                 /*
1315                  * Do not complain the most common case
1316                  *      git checkout branch
1317                  * even if there happen to be a file called 'branch';
1318                  * it would be extremely annoying.
1319                  */
1320                 if (argc)
1321                         verify_non_filename(opts->prefix, arg);
1322         } else if (opts->accept_pathspec) {
1323                 argcount++;
1324                 argv++;
1325                 argc--;
1326         }
1327
1328         return argcount;
1329 }
1330
1331 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1332 {
1333         int status;
1334         struct strbuf branch_ref = STRBUF_INIT;
1335
1336         trace2_cmd_mode("unborn");
1337
1338         if (!opts->new_branch)
1339                 die(_("You are on a branch yet to be born"));
1340         strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1341         status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1342         strbuf_release(&branch_ref);
1343         if (!opts->quiet)
1344                 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1345                         opts->new_branch);
1346         return status;
1347 }
1348
1349 static void die_expecting_a_branch(const struct branch_info *branch_info)
1350 {
1351         struct object_id oid;
1352         char *to_free;
1353
1354         if (dwim_ref(branch_info->name, strlen(branch_info->name), &oid, &to_free) == 1) {
1355                 const char *ref = to_free;
1356
1357                 if (skip_prefix(ref, "refs/tags/", &ref))
1358                         die(_("a branch is expected, got tag '%s'"), ref);
1359                 if (skip_prefix(ref, "refs/remotes/", &ref))
1360                         die(_("a branch is expected, got remote branch '%s'"), ref);
1361                 die(_("a branch is expected, got '%s'"), ref);
1362         }
1363         if (branch_info->commit)
1364                 die(_("a branch is expected, got commit '%s'"), branch_info->name);
1365         /*
1366          * This case should never happen because we already die() on
1367          * non-commit, but just in case.
1368          */
1369         die(_("a branch is expected, got '%s'"), branch_info->name);
1370 }
1371
1372 static void die_if_some_operation_in_progress(void)
1373 {
1374         struct wt_status_state state;
1375
1376         memset(&state, 0, sizeof(state));
1377         wt_status_get_state(the_repository, &state, 0);
1378
1379         if (state.merge_in_progress)
1380                 die(_("cannot switch branch while merging\n"
1381                       "Consider \"git merge --quit\" "
1382                       "or \"git worktree add\"."));
1383         if (state.am_in_progress)
1384                 die(_("cannot switch branch in the middle of an am session\n"
1385                       "Consider \"git am --quit\" "
1386                       "or \"git worktree add\"."));
1387         if (state.rebase_interactive_in_progress || state.rebase_in_progress)
1388                 die(_("cannot switch branch while rebasing\n"
1389                       "Consider \"git rebase --quit\" "
1390                       "or \"git worktree add\"."));
1391         if (state.cherry_pick_in_progress)
1392                 die(_("cannot switch branch while cherry-picking\n"
1393                       "Consider \"git cherry-pick --quit\" "
1394                       "or \"git worktree add\"."));
1395         if (state.revert_in_progress)
1396                 die(_("cannot switch branch while reverting\n"
1397                       "Consider \"git revert --quit\" "
1398                       "or \"git worktree add\"."));
1399         if (state.bisect_in_progress)
1400                 warning(_("you are switching branch while bisecting"));
1401 }
1402
1403 static int checkout_branch(struct checkout_opts *opts,
1404                            struct branch_info *new_branch_info)
1405 {
1406         if (opts->pathspec.nr)
1407                 die(_("paths cannot be used with switching branches"));
1408
1409         if (opts->patch_mode)
1410                 die(_("'%s' cannot be used with switching branches"),
1411                     "--patch");
1412
1413         if (opts->overlay_mode != -1)
1414                 die(_("'%s' cannot be used with switching branches"),
1415                     "--[no]-overlay");
1416
1417         if (opts->writeout_stage)
1418                 die(_("'%s' cannot be used with switching branches"),
1419                     "--ours/--theirs");
1420
1421         if (opts->force && opts->merge)
1422                 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1423
1424         if (opts->discard_changes && opts->merge)
1425                 die(_("'%s' cannot be used with '%s'"), "--discard-changes", "--merge");
1426
1427         if (opts->force_detach && opts->new_branch)
1428                 die(_("'%s' cannot be used with '%s'"),
1429                     "--detach", "-b/-B/--orphan");
1430
1431         if (opts->new_orphan_branch) {
1432                 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1433                         die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1434                 if (opts->orphan_from_empty_tree && new_branch_info->name)
1435                         die(_("'%s' cannot take <start-point>"), "--orphan");
1436         } else if (opts->force_detach) {
1437                 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1438                         die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1439         } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1440                 opts->track = git_branch_track;
1441
1442         if (new_branch_info->name && !new_branch_info->commit)
1443                 die(_("Cannot switch branch to a non-commit '%s'"),
1444                     new_branch_info->name);
1445
1446         if (!opts->switch_branch_doing_nothing_is_ok &&
1447             !new_branch_info->name &&
1448             !opts->new_branch &&
1449             !opts->force_detach)
1450                 die(_("missing branch or commit argument"));
1451
1452         if (!opts->implicit_detach &&
1453             !opts->force_detach &&
1454             !opts->new_branch &&
1455             !opts->new_branch_force &&
1456             new_branch_info->name &&
1457             !new_branch_info->path)
1458                 die_expecting_a_branch(new_branch_info);
1459
1460         if (!opts->can_switch_when_in_progress)
1461                 die_if_some_operation_in_progress();
1462
1463         if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
1464             !opts->ignore_other_worktrees) {
1465                 int flag;
1466                 char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
1467                 if (head_ref &&
1468                     (!(flag & REF_ISSYMREF) || strcmp(head_ref, new_branch_info->path)))
1469                         die_if_checked_out(new_branch_info->path, 1);
1470                 free(head_ref);
1471         }
1472
1473         if (!new_branch_info->commit && opts->new_branch) {
1474                 struct object_id rev;
1475                 int flag;
1476
1477                 if (!read_ref_full("HEAD", 0, &rev, &flag) &&
1478                     (flag & REF_ISSYMREF) && is_null_oid(&rev))
1479                         return switch_unborn_to_new_branch(opts);
1480         }
1481         return switch_branches(opts, new_branch_info);
1482 }
1483
1484 static struct option *add_common_options(struct checkout_opts *opts,
1485                                          struct option *prevopts)
1486 {
1487         struct option options[] = {
1488                 OPT__QUIET(&opts->quiet, N_("suppress progress reporting")),
1489                 OPT_CALLBACK_F(0, "recurse-submodules", NULL,
1490                             "checkout", "control recursive updating of submodules",
1491                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
1492                 OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
1493                 OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
1494                 OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
1495                            N_("conflict style (merge or diff3)")),
1496                 OPT_END()
1497         };
1498         struct option *newopts = parse_options_concat(prevopts, options);
1499         free(prevopts);
1500         return newopts;
1501 }
1502
1503 static struct option *add_common_switch_branch_options(
1504         struct checkout_opts *opts, struct option *prevopts)
1505 {
1506         struct option options[] = {
1507                 OPT_BOOL('d', "detach", &opts->force_detach, N_("detach HEAD at named commit")),
1508                 OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
1509                         BRANCH_TRACK_EXPLICIT),
1510                 OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
1511                            PARSE_OPT_NOCOMPLETE),
1512                 OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1513                 OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
1514                            N_("update ignored files (default)"),
1515                            PARSE_OPT_NOCOMPLETE),
1516                 OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
1517                          N_("do not check if another worktree is holding the given ref")),
1518                 OPT_END()
1519         };
1520         struct option *newopts = parse_options_concat(prevopts, options);
1521         free(prevopts);
1522         return newopts;
1523 }
1524
1525 static struct option *add_checkout_path_options(struct checkout_opts *opts,
1526                                                 struct option *prevopts)
1527 {
1528         struct option options[] = {
1529                 OPT_SET_INT_F('2', "ours", &opts->writeout_stage,
1530                               N_("checkout our version for unmerged files"),
1531                               2, PARSE_OPT_NONEG),
1532                 OPT_SET_INT_F('3', "theirs", &opts->writeout_stage,
1533                               N_("checkout their version for unmerged files"),
1534                               3, PARSE_OPT_NONEG),
1535                 OPT_BOOL('p', "patch", &opts->patch_mode, N_("select hunks interactively")),
1536                 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts->ignore_skipworktree,
1537                          N_("do not limit pathspecs to sparse entries only")),
1538                 OPT_PATHSPEC_FROM_FILE(&opts->pathspec_from_file),
1539                 OPT_PATHSPEC_FILE_NUL(&opts->pathspec_file_nul),
1540                 OPT_END()
1541         };
1542         struct option *newopts = parse_options_concat(prevopts, options);
1543         free(prevopts);
1544         return newopts;
1545 }
1546
1547 /* create-branch option (either b or c) */
1548 static char cb_option = 'b';
1549
1550 static int checkout_main(int argc, const char **argv, const char *prefix,
1551                          struct checkout_opts *opts, struct option *options,
1552                          const char * const usagestr[])
1553 {
1554         struct branch_info new_branch_info;
1555         int parseopt_flags = 0;
1556
1557         memset(&new_branch_info, 0, sizeof(new_branch_info));
1558         opts->overwrite_ignore = 1;
1559         opts->prefix = prefix;
1560         opts->show_progress = -1;
1561
1562         git_config(git_checkout_config, opts);
1563
1564         opts->track = BRANCH_TRACK_UNSPECIFIED;
1565
1566         if (!opts->accept_pathspec && !opts->accept_ref)
1567                 BUG("make up your mind, you need to take _something_");
1568         if (opts->accept_pathspec && opts->accept_ref)
1569                 parseopt_flags = PARSE_OPT_KEEP_DASHDASH;
1570
1571         argc = parse_options(argc, argv, prefix, options,
1572                              usagestr, parseopt_flags);
1573
1574         if (opts->show_progress < 0) {
1575                 if (opts->quiet)
1576                         opts->show_progress = 0;
1577                 else
1578                         opts->show_progress = isatty(2);
1579         }
1580
1581         if (opts->conflict_style) {
1582                 opts->merge = 1; /* implied */
1583                 git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL);
1584         }
1585         if (opts->force) {
1586                 opts->discard_changes = 1;
1587                 opts->ignore_unmerged_opt = "--force";
1588                 opts->ignore_unmerged = 1;
1589         }
1590
1591         if ((!!opts->new_branch + !!opts->new_branch_force + !!opts->new_orphan_branch) > 1)
1592                 die(_("-%c, -%c and --orphan are mutually exclusive"),
1593                                 cb_option, toupper(cb_option));
1594
1595         if (opts->overlay_mode == 1 && opts->patch_mode)
1596                 die(_("-p and --overlay are mutually exclusive"));
1597
1598         if (opts->checkout_index >= 0 || opts->checkout_worktree >= 0) {
1599                 if (opts->checkout_index < 0)
1600                         opts->checkout_index = 0;
1601                 if (opts->checkout_worktree < 0)
1602                         opts->checkout_worktree = 0;
1603         } else {
1604                 if (opts->checkout_index < 0)
1605                         opts->checkout_index = -opts->checkout_index - 1;
1606                 if (opts->checkout_worktree < 0)
1607                         opts->checkout_worktree = -opts->checkout_worktree - 1;
1608         }
1609         if (opts->checkout_index < 0 || opts->checkout_worktree < 0)
1610                 BUG("these flags should be non-negative by now");
1611         /*
1612          * convenient shortcut: "git restore --staged [--worktree]" equals
1613          * "git restore --staged [--worktree] --source HEAD"
1614          */
1615         if (!opts->from_treeish && opts->checkout_index)
1616                 opts->from_treeish = "HEAD";
1617
1618         /*
1619          * From here on, new_branch will contain the branch to be checked out,
1620          * and new_branch_force and new_orphan_branch will tell us which one of
1621          * -b/-B/-c/-C/--orphan is being used.
1622          */
1623         if (opts->new_branch_force)
1624                 opts->new_branch = opts->new_branch_force;
1625
1626         if (opts->new_orphan_branch)
1627                 opts->new_branch = opts->new_orphan_branch;
1628
1629         /* --track without -c/-C/-b/-B/--orphan should DWIM */
1630         if (opts->track != BRANCH_TRACK_UNSPECIFIED && !opts->new_branch) {
1631                 const char *argv0 = argv[0];
1632                 if (!argc || !strcmp(argv0, "--"))
1633                         die(_("--track needs a branch name"));
1634                 skip_prefix(argv0, "refs/", &argv0);
1635                 skip_prefix(argv0, "remotes/", &argv0);
1636                 argv0 = strchr(argv0, '/');
1637                 if (!argv0 || !argv0[1])
1638                         die(_("missing branch name; try -%c"), cb_option);
1639                 opts->new_branch = argv0 + 1;
1640         }
1641
1642         /*
1643          * Extract branch name from command line arguments, so
1644          * all that is left is pathspecs.
1645          *
1646          * Handle
1647          *
1648          *  1) git checkout <tree> -- [<paths>]
1649          *  2) git checkout -- [<paths>]
1650          *  3) git checkout <something> [<paths>]
1651          *
1652          * including "last branch" syntax and DWIM-ery for names of
1653          * remote branches, erroring out for invalid or ambiguous cases.
1654          */
1655         if (argc && opts->accept_ref) {
1656                 struct object_id rev;
1657                 int dwim_ok =
1658                         !opts->patch_mode &&
1659                         opts->dwim_new_local_branch &&
1660                         opts->track == BRANCH_TRACK_UNSPECIFIED &&
1661                         !opts->new_branch;
1662                 int n = parse_branchname_arg(argc, argv, dwim_ok,
1663                                              &new_branch_info, opts, &rev);
1664                 argv += n;
1665                 argc -= n;
1666         } else if (!opts->accept_ref && opts->from_treeish) {
1667                 struct object_id rev;
1668
1669                 if (get_oid_mb(opts->from_treeish, &rev))
1670                         die(_("could not resolve %s"), opts->from_treeish);
1671
1672                 setup_new_branch_info_and_source_tree(&new_branch_info,
1673                                                       opts, &rev,
1674                                                       opts->from_treeish);
1675
1676                 if (!opts->source_tree)
1677                         die(_("reference is not a tree: %s"), opts->from_treeish);
1678         }
1679
1680         if (argc) {
1681                 parse_pathspec(&opts->pathspec, 0,
1682                                opts->patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1683                                prefix, argv);
1684
1685                 if (!opts->pathspec.nr)
1686                         die(_("invalid path specification"));
1687
1688                 /*
1689                  * Try to give more helpful suggestion.
1690                  * new_branch && argc > 1 will be caught later.
1691                  */
1692                 if (opts->new_branch && argc == 1)
1693                         die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1694                                 argv[0], opts->new_branch);
1695
1696                 if (opts->force_detach)
1697                         die(_("git checkout: --detach does not take a path argument '%s'"),
1698                             argv[0]);
1699         }
1700
1701         if (opts->pathspec_from_file) {
1702                 if (opts->pathspec.nr)
1703                         die(_("--pathspec-from-file is incompatible with pathspec arguments"));
1704
1705                 if (opts->force_detach)
1706                         die(_("--pathspec-from-file is incompatible with --detach"));
1707
1708                 if (opts->patch_mode)
1709                         die(_("--pathspec-from-file is incompatible with --patch"));
1710
1711                 parse_pathspec_file(&opts->pathspec, 0,
1712                                     0,
1713                                     prefix, opts->pathspec_from_file, opts->pathspec_file_nul);
1714         } else if (opts->pathspec_file_nul) {
1715                 die(_("--pathspec-file-nul requires --pathspec-from-file"));
1716         }
1717
1718         if (opts->pathspec.nr) {
1719                 if (1 < !!opts->writeout_stage + !!opts->force + !!opts->merge)
1720                         die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1721                               "checking out of the index."));
1722         } else {
1723                 if (opts->accept_pathspec && !opts->empty_pathspec_ok &&
1724                     !opts->patch_mode)  /* patch mode is special */
1725                         die(_("you must specify path(s) to restore"));
1726         }
1727
1728         if (opts->new_branch) {
1729                 struct strbuf buf = STRBUF_INIT;
1730
1731                 if (opts->new_branch_force)
1732                         opts->branch_exists = validate_branchname(opts->new_branch, &buf);
1733                 else
1734                         opts->branch_exists =
1735                                 validate_new_branchname(opts->new_branch, &buf, 0);
1736                 strbuf_release(&buf);
1737         }
1738
1739         UNLEAK(opts);
1740         if (opts->patch_mode || opts->pathspec.nr)
1741                 return checkout_paths(opts, &new_branch_info);
1742         else
1743                 return checkout_branch(opts, &new_branch_info);
1744 }
1745
1746 int cmd_checkout(int argc, const char **argv, const char *prefix)
1747 {
1748         struct checkout_opts opts;
1749         struct option *options;
1750         struct option checkout_options[] = {
1751                 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1752                            N_("create and checkout a new branch")),
1753                 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1754                            N_("create/reset and checkout a branch")),
1755                 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1756                 OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
1757                          N_("second guess 'git checkout <no-such-branch>' (default)")),
1758                 OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode (default)")),
1759                 OPT_END()
1760         };
1761         int ret;
1762
1763         memset(&opts, 0, sizeof(opts));
1764         opts.dwim_new_local_branch = 1;
1765         opts.switch_branch_doing_nothing_is_ok = 1;
1766         opts.only_merge_on_switching_branches = 0;
1767         opts.accept_ref = 1;
1768         opts.accept_pathspec = 1;
1769         opts.implicit_detach = 1;
1770         opts.can_switch_when_in_progress = 1;
1771         opts.orphan_from_empty_tree = 0;
1772         opts.empty_pathspec_ok = 1;
1773         opts.overlay_mode = -1;
1774         opts.checkout_index = -2;    /* default on */
1775         opts.checkout_worktree = -2; /* default on */
1776
1777         if (argc == 3 && !strcmp(argv[1], "-b")) {
1778                 /*
1779                  * User ran 'git checkout -b <branch>' and expects
1780                  * the same behavior as 'git switch -c <branch>'.
1781                  */
1782                 opts.switch_branch_doing_nothing_is_ok = 0;
1783                 opts.only_merge_on_switching_branches = 1;
1784         }
1785
1786         options = parse_options_dup(checkout_options);
1787         options = add_common_options(&opts, options);
1788         options = add_common_switch_branch_options(&opts, options);
1789         options = add_checkout_path_options(&opts, options);
1790
1791         ret = checkout_main(argc, argv, prefix, &opts,
1792                             options, checkout_usage);
1793         FREE_AND_NULL(options);
1794         return ret;
1795 }
1796
1797 int cmd_switch(int argc, const char **argv, const char *prefix)
1798 {
1799         struct checkout_opts opts;
1800         struct option *options = NULL;
1801         struct option switch_options[] = {
1802                 OPT_STRING('c', "create", &opts.new_branch, N_("branch"),
1803                            N_("create and switch to a new branch")),
1804                 OPT_STRING('C', "force-create", &opts.new_branch_force, N_("branch"),
1805                            N_("create/reset and switch to a branch")),
1806                 OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
1807                          N_("second guess 'git switch <no-such-branch>'")),
1808                 OPT_BOOL(0, "discard-changes", &opts.discard_changes,
1809                          N_("throw away local modifications")),
1810                 OPT_END()
1811         };
1812         int ret;
1813
1814         memset(&opts, 0, sizeof(opts));
1815         opts.dwim_new_local_branch = 1;
1816         opts.accept_ref = 1;
1817         opts.accept_pathspec = 0;
1818         opts.switch_branch_doing_nothing_is_ok = 0;
1819         opts.only_merge_on_switching_branches = 1;
1820         opts.implicit_detach = 0;
1821         opts.can_switch_when_in_progress = 0;
1822         opts.orphan_from_empty_tree = 1;
1823         opts.overlay_mode = -1;
1824
1825         options = parse_options_dup(switch_options);
1826         options = add_common_options(&opts, options);
1827         options = add_common_switch_branch_options(&opts, options);
1828
1829         cb_option = 'c';
1830
1831         ret = checkout_main(argc, argv, prefix, &opts,
1832                             options, switch_branch_usage);
1833         FREE_AND_NULL(options);
1834         return ret;
1835 }
1836
1837 int cmd_restore(int argc, const char **argv, const char *prefix)
1838 {
1839         struct checkout_opts opts;
1840         struct option *options;
1841         struct option restore_options[] = {
1842                 OPT_STRING('s', "source", &opts.from_treeish, "<tree-ish>",
1843                            N_("which tree-ish to checkout from")),
1844                 OPT_BOOL('S', "staged", &opts.checkout_index,
1845                            N_("restore the index")),
1846                 OPT_BOOL('W', "worktree", &opts.checkout_worktree,
1847                            N_("restore the working tree (default)")),
1848                 OPT_BOOL(0, "ignore-unmerged", &opts.ignore_unmerged,
1849                          N_("ignore unmerged entries")),
1850                 OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode")),
1851                 OPT_END()
1852         };
1853         int ret;
1854
1855         memset(&opts, 0, sizeof(opts));
1856         opts.accept_ref = 0;
1857         opts.accept_pathspec = 1;
1858         opts.empty_pathspec_ok = 0;
1859         opts.overlay_mode = 0;
1860         opts.checkout_index = -1;    /* default off */
1861         opts.checkout_worktree = -2; /* default on */
1862         opts.ignore_unmerged_opt = "--ignore-unmerged";
1863
1864         options = parse_options_dup(restore_options);
1865         options = add_common_options(&opts, options);
1866         options = add_checkout_path_options(&opts, options);
1867
1868         ret = checkout_main(argc, argv, prefix, &opts,
1869                             options, restore_usage);
1870         FREE_AND_NULL(options);
1871         return ret;
1872 }