f7967cdb7c9eca20e40ba5edc2224c79f10f766f
   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 "xdiff-interface.h"
  28
  29static const char * const checkout_usage[] = {
  30        N_("git checkout [<options>] <branch>"),
  31        N_("git checkout [<options>] [<branch>] -- <file>..."),
  32        NULL,
  33};
  34
  35static const char * const switch_branch_usage[] = {
  36        N_("git switch [<options>] [<branch>]"),
  37        NULL,
  38};
  39
  40struct checkout_opts {
  41        int patch_mode;
  42        int quiet;
  43        int merge;
  44        int force;
  45        int force_detach;
  46        int implicit_detach;
  47        int writeout_stage;
  48        int overwrite_ignore;
  49        int ignore_skipworktree;
  50        int ignore_other_worktrees;
  51        int show_progress;
  52        int count_checkout_paths;
  53        int overlay_mode;
  54        int dwim_new_local_branch;
  55        int discard_changes;
  56        int accept_pathspec;
  57        int switch_branch_doing_nothing_is_ok;
  58        int only_merge_on_switching_branches;
  59
  60        const char *new_branch;
  61        const char *new_branch_force;
  62        const char *new_orphan_branch;
  63        int new_branch_log;
  64        enum branch_track track;
  65        struct diff_options diff_options;
  66        char *conflict_style;
  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_commit, struct commit *new_commit,
  75                              int changed)
  76{
  77        return run_hook_le(NULL, "post-checkout",
  78                           oid_to_hex(old_commit ? &old_commit->object.oid : &null_oid),
  79                           oid_to_hex(new_commit ? &new_commit->object.oid : &null_oid),
  80                           changed ? "1" : "0", NULL);
  81        /* "new_commit" can be NULL when checking out from the index before
  82           a commit exists. */
  83
  84}
  85
  86static int update_some(const struct object_id *oid, 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 = make_empty_cache_entry(&the_index, len);
  98        oidcpy(&ce->oid, oid);
  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                    oideq(&ce->oid, &old->oid)) {
 115                        old->ce_flags |= CE_UPDATE;
 116                        discard_cache_entry(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(the_repository, tree, "", 0, 0,
 128                            pathspec, update_some, NULL);
 129
 130        /* update the index with the given tree's info
 131         * for all args, expanding wildcards, and exit
 132         * with any non-zero return code.
 133         */
 134        return 0;
 135}
 136
 137static int skip_same_name(const struct cache_entry *ce, int pos)
 138{
 139        while (++pos < active_nr &&
 140               !strcmp(active_cache[pos]->name, ce->name))
 141                ; /* skip */
 142        return pos;
 143}
 144
 145static int check_stage(int stage, const struct cache_entry *ce, int pos,
 146                       int overlay_mode)
 147{
 148        while (pos < active_nr &&
 149               !strcmp(active_cache[pos]->name, ce->name)) {
 150                if (ce_stage(active_cache[pos]) == stage)
 151                        return 0;
 152                pos++;
 153        }
 154        if (!overlay_mode)
 155                return 0;
 156        if (stage == 2)
 157                return error(_("path '%s' does not have our version"), ce->name);
 158        else
 159                return error(_("path '%s' does not have their version"), ce->name);
 160}
 161
 162static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
 163{
 164        unsigned seen = 0;
 165        const char *name = ce->name;
 166
 167        while (pos < active_nr) {
 168                ce = active_cache[pos];
 169                if (strcmp(name, ce->name))
 170                        break;
 171                seen |= (1 << ce_stage(ce));
 172                pos++;
 173        }
 174        if ((stages & seen) != stages)
 175                return error(_("path '%s' does not have all necessary versions"),
 176                             name);
 177        return 0;
 178}
 179
 180static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
 181                          const struct checkout *state, int *nr_checkouts,
 182                          int overlay_mode)
 183{
 184        while (pos < active_nr &&
 185               !strcmp(active_cache[pos]->name, ce->name)) {
 186                if (ce_stage(active_cache[pos]) == stage)
 187                        return checkout_entry(active_cache[pos], state,
 188                                              NULL, nr_checkouts);
 189                pos++;
 190        }
 191        if (!overlay_mode) {
 192                unlink_entry(ce);
 193                return 0;
 194        }
 195        if (stage == 2)
 196                return error(_("path '%s' does not have our version"), ce->name);
 197        else
 198                return error(_("path '%s' does not have their version"), ce->name);
 199}
 200
 201static int checkout_merged(int pos, const struct checkout *state, int *nr_checkouts)
 202{
 203        struct cache_entry *ce = active_cache[pos];
 204        const char *path = ce->name;
 205        mmfile_t ancestor, ours, theirs;
 206        int status;
 207        struct object_id oid;
 208        mmbuffer_t result_buf;
 209        struct object_id threeway[3];
 210        unsigned mode = 0;
 211
 212        memset(threeway, 0, sizeof(threeway));
 213        while (pos < active_nr) {
 214                int stage;
 215                stage = ce_stage(ce);
 216                if (!stage || strcmp(path, ce->name))
 217                        break;
 218                oidcpy(&threeway[stage - 1], &ce->oid);
 219                if (stage == 2)
 220                        mode = create_ce_mode(ce->ce_mode);
 221                pos++;
 222                ce = active_cache[pos];
 223        }
 224        if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
 225                return error(_("path '%s' does not have necessary versions"), path);
 226
 227        read_mmblob(&ancestor, &threeway[0]);
 228        read_mmblob(&ours, &threeway[1]);
 229        read_mmblob(&theirs, &threeway[2]);
 230
 231        /*
 232         * NEEDSWORK: re-create conflicts from merges with
 233         * merge.renormalize set, too
 234         */
 235        status = ll_merge(&result_buf, path, &ancestor, "base",
 236                          &ours, "ours", &theirs, "theirs",
 237                          state->istate, NULL);
 238        free(ancestor.ptr);
 239        free(ours.ptr);
 240        free(theirs.ptr);
 241        if (status < 0 || !result_buf.ptr) {
 242                free(result_buf.ptr);
 243                return error(_("path '%s': cannot merge"), path);
 244        }
 245
 246        /*
 247         * NEEDSWORK:
 248         * There is absolutely no reason to write this as a blob object
 249         * and create a phony cache entry.  This hack is primarily to get
 250         * to the write_entry() machinery that massages the contents to
 251         * work-tree format and writes out which only allows it for a
 252         * cache entry.  The code in write_entry() needs to be refactored
 253         * to allow us to feed a <buffer, size, mode> instead of a cache
 254         * entry.  Such a refactoring would help merge_recursive as well
 255         * (it also writes the merge result to the object database even
 256         * when it may contain conflicts).
 257         */
 258        if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
 259                die(_("Unable to add merge result for '%s'"), path);
 260        free(result_buf.ptr);
 261        ce = make_transient_cache_entry(mode, &oid, path, 2);
 262        if (!ce)
 263                die(_("make_cache_entry failed for path '%s'"), path);
 264        status = checkout_entry(ce, state, NULL, nr_checkouts);
 265        discard_cache_entry(ce);
 266        return status;
 267}
 268
 269static void mark_ce_for_checkout_overlay(struct cache_entry *ce,
 270                                         char *ps_matched,
 271                                         const struct checkout_opts *opts)
 272{
 273        ce->ce_flags &= ~CE_MATCHED;
 274        if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
 275                return;
 276        if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
 277                /*
 278                 * "git checkout tree-ish -- path", but this entry
 279                 * is in the original index but is not in tree-ish
 280                 * or does not match the pathspec; it will not be
 281                 * checked out to the working tree.  We will not do
 282                 * anything to this entry at all.
 283                 */
 284                return;
 285        /*
 286         * Either this entry came from the tree-ish we are
 287         * checking the paths out of, or we are checking out
 288         * of the index.
 289         *
 290         * If it comes from the tree-ish, we already know it
 291         * matches the pathspec and could just stamp
 292         * CE_MATCHED to it from update_some(). But we still
 293         * need ps_matched and read_tree_recursive (and
 294         * eventually tree_entry_interesting) cannot fill
 295         * ps_matched yet. Once it can, we can avoid calling
 296         * match_pathspec() for _all_ entries when
 297         * opts->source_tree != NULL.
 298         */
 299        if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched))
 300                ce->ce_flags |= CE_MATCHED;
 301}
 302
 303static void mark_ce_for_checkout_no_overlay(struct cache_entry *ce,
 304                                            char *ps_matched,
 305                                            const struct checkout_opts *opts)
 306{
 307        ce->ce_flags &= ~CE_MATCHED;
 308        if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
 309                return;
 310        if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched)) {
 311                ce->ce_flags |= CE_MATCHED;
 312                if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
 313                        /*
 314                         * In overlay mode, but the path is not in
 315                         * tree-ish, which means we should remove it
 316                         * from the index and the working tree.
 317                         */
 318                        ce->ce_flags |= CE_REMOVE | CE_WT_REMOVE;
 319        }
 320}
 321
 322static int checkout_paths(const struct checkout_opts *opts,
 323                          const char *revision)
 324{
 325        int pos;
 326        struct checkout state = CHECKOUT_INIT;
 327        static char *ps_matched;
 328        struct object_id rev;
 329        struct commit *head;
 330        int errs = 0;
 331        struct lock_file lock_file = LOCK_INIT;
 332        int nr_checkouts = 0, nr_unmerged = 0;
 333
 334        trace2_cmd_mode(opts->patch_mode ? "patch" : "path");
 335
 336        if (opts->track != BRANCH_TRACK_UNSPECIFIED)
 337                die(_("'%s' cannot be used with updating paths"), "--track");
 338
 339        if (opts->new_branch_log)
 340                die(_("'%s' cannot be used with updating paths"), "-l");
 341
 342        if (opts->force && opts->patch_mode)
 343                die(_("'%s' cannot be used with updating paths"), "-f");
 344
 345        if (opts->force_detach)
 346                die(_("'%s' cannot be used with updating paths"), "--detach");
 347
 348        if (opts->merge && opts->patch_mode)
 349                die(_("'%s' cannot be used with %s"), "--merge", "--patch");
 350
 351        if (opts->force && opts->merge)
 352                die(_("'%s' cannot be used with %s"), "-f", "-m");
 353
 354        if (opts->new_branch)
 355                die(_("Cannot update paths and switch to branch '%s' at the same time."),
 356                    opts->new_branch);
 357
 358        if (opts->patch_mode)
 359                return run_add_interactive(revision, "--patch=checkout",
 360                                           &opts->pathspec);
 361
 362        repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 363        if (read_cache_preload(&opts->pathspec) < 0)
 364                return error(_("index file corrupt"));
 365
 366        if (opts->source_tree)
 367                read_tree_some(opts->source_tree, &opts->pathspec);
 368
 369        ps_matched = xcalloc(opts->pathspec.nr, 1);
 370
 371        /*
 372         * Make sure all pathspecs participated in locating the paths
 373         * to be checked out.
 374         */
 375        for (pos = 0; pos < active_nr; pos++)
 376                if (opts->overlay_mode)
 377                        mark_ce_for_checkout_overlay(active_cache[pos],
 378                                                     ps_matched,
 379                                                     opts);
 380                else
 381                        mark_ce_for_checkout_no_overlay(active_cache[pos],
 382                                                        ps_matched,
 383                                                        opts);
 384
 385        if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
 386                free(ps_matched);
 387                return 1;
 388        }
 389        free(ps_matched);
 390
 391        /* "checkout -m path" to recreate conflicted state */
 392        if (opts->merge)
 393                unmerge_marked_index(&the_index);
 394
 395        /* Any unmerged paths? */
 396        for (pos = 0; pos < active_nr; pos++) {
 397                const struct cache_entry *ce = active_cache[pos];
 398                if (ce->ce_flags & CE_MATCHED) {
 399                        if (!ce_stage(ce))
 400                                continue;
 401                        if (opts->force) {
 402                                warning(_("path '%s' is unmerged"), ce->name);
 403                        } else if (opts->writeout_stage) {
 404                                errs |= check_stage(opts->writeout_stage, ce, pos, opts->overlay_mode);
 405                        } else if (opts->merge) {
 406                                errs |= check_stages((1<<2) | (1<<3), ce, pos);
 407                        } else {
 408                                errs = 1;
 409                                error(_("path '%s' is unmerged"), ce->name);
 410                        }
 411                        pos = skip_same_name(ce, pos) - 1;
 412                }
 413        }
 414        if (errs)
 415                return 1;
 416
 417        /* Now we are committed to check them out */
 418        state.force = 1;
 419        state.refresh_cache = 1;
 420        state.istate = &the_index;
 421
 422        enable_delayed_checkout(&state);
 423        for (pos = 0; pos < active_nr; pos++) {
 424                struct cache_entry *ce = active_cache[pos];
 425                if (ce->ce_flags & CE_MATCHED) {
 426                        if (!ce_stage(ce)) {
 427                                errs |= checkout_entry(ce, &state,
 428                                                       NULL, &nr_checkouts);
 429                                continue;
 430                        }
 431                        if (opts->writeout_stage)
 432                                errs |= checkout_stage(opts->writeout_stage,
 433                                                       ce, pos,
 434                                                       &state,
 435                                                       &nr_checkouts, opts->overlay_mode);
 436                        else if (opts->merge)
 437                                errs |= checkout_merged(pos, &state,
 438                                                        &nr_unmerged);
 439                        pos = skip_same_name(ce, pos) - 1;
 440                }
 441        }
 442        remove_marked_cache_entries(&the_index, 1);
 443        remove_scheduled_dirs();
 444        errs |= finish_delayed_checkout(&state, &nr_checkouts);
 445
 446        if (opts->count_checkout_paths) {
 447                if (nr_unmerged)
 448                        fprintf_ln(stderr, Q_("Recreated %d merge conflict",
 449                                              "Recreated %d merge conflicts",
 450                                              nr_unmerged),
 451                                   nr_unmerged);
 452                if (opts->source_tree)
 453                        fprintf_ln(stderr, Q_("Updated %d path from %s",
 454                                              "Updated %d paths from %s",
 455                                              nr_checkouts),
 456                                   nr_checkouts,
 457                                   find_unique_abbrev(&opts->source_tree->object.oid,
 458                                                      DEFAULT_ABBREV));
 459                else if (!nr_unmerged || nr_checkouts)
 460                        fprintf_ln(stderr, Q_("Updated %d path from the index",
 461                                              "Updated %d paths from the index",
 462                                              nr_checkouts),
 463                                   nr_checkouts);
 464        }
 465
 466        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 467                die(_("unable to write new index file"));
 468
 469        read_ref_full("HEAD", 0, &rev, NULL);
 470        head = lookup_commit_reference_gently(the_repository, &rev, 1);
 471
 472        errs |= post_checkout_hook(head, head, 0);
 473        return errs;
 474}
 475
 476static void show_local_changes(struct object *head,
 477                               const struct diff_options *opts)
 478{
 479        struct rev_info rev;
 480        /* I think we want full paths, even if we're in a subdirectory. */
 481        repo_init_revisions(the_repository, &rev, NULL);
 482        rev.diffopt.flags = opts->flags;
 483        rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
 484        diff_setup_done(&rev.diffopt);
 485        add_pending_object(&rev, head, NULL);
 486        run_diff_index(&rev, 0);
 487}
 488
 489static void describe_detached_head(const char *msg, struct commit *commit)
 490{
 491        struct strbuf sb = STRBUF_INIT;
 492
 493        if (!parse_commit(commit))
 494                pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
 495        if (print_sha1_ellipsis()) {
 496                fprintf(stderr, "%s %s... %s\n", msg,
 497                        find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
 498        } else {
 499                fprintf(stderr, "%s %s %s\n", msg,
 500                        find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
 501        }
 502        strbuf_release(&sb);
 503}
 504
 505static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 506                      int worktree, int *writeout_error)
 507{
 508        struct unpack_trees_options opts;
 509        struct tree_desc tree_desc;
 510
 511        memset(&opts, 0, sizeof(opts));
 512        opts.head_idx = -1;
 513        opts.update = worktree;
 514        opts.skip_unmerged = !worktree;
 515        opts.reset = 1;
 516        opts.merge = 1;
 517        opts.fn = oneway_merge;
 518        opts.verbose_update = o->show_progress;
 519        opts.src_index = &the_index;
 520        opts.dst_index = &the_index;
 521        parse_tree(tree);
 522        init_tree_desc(&tree_desc, tree->buffer, tree->size);
 523        switch (unpack_trees(1, &tree_desc, &opts)) {
 524        case -2:
 525                *writeout_error = 1;
 526                /*
 527                 * We return 0 nevertheless, as the index is all right
 528                 * and more importantly we have made best efforts to
 529                 * update paths in the work tree, and we cannot revert
 530                 * them.
 531                 */
 532                /* fallthrough */
 533        case 0:
 534                return 0;
 535        default:
 536                return 128;
 537        }
 538}
 539
 540struct branch_info {
 541        const char *name; /* The short name used */
 542        const char *path; /* The full name of a real branch */
 543        struct commit *commit; /* The named commit */
 544        /*
 545         * if not null the branch is detached because it's already
 546         * checked out in this checkout
 547         */
 548        char *checkout;
 549};
 550
 551static void setup_branch_path(struct branch_info *branch)
 552{
 553        struct strbuf buf = STRBUF_INIT;
 554
 555        strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
 556        if (strcmp(buf.buf, branch->name))
 557                branch->name = xstrdup(buf.buf);
 558        strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
 559        branch->path = strbuf_detach(&buf, NULL);
 560}
 561
 562static int merge_working_tree(const struct checkout_opts *opts,
 563                              struct branch_info *old_branch_info,
 564                              struct branch_info *new_branch_info,
 565                              int *writeout_error)
 566{
 567        int ret;
 568        struct lock_file lock_file = LOCK_INIT;
 569
 570        hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 571        if (read_cache_preload(NULL) < 0)
 572                return error(_("index file corrupt"));
 573
 574        resolve_undo_clear();
 575        if (opts->discard_changes) {
 576                ret = reset_tree(get_commit_tree(new_branch_info->commit),
 577                                 opts, 1, writeout_error);
 578                if (ret)
 579                        return ret;
 580        } else {
 581                struct tree_desc trees[2];
 582                struct tree *tree;
 583                struct unpack_trees_options topts;
 584
 585                memset(&topts, 0, sizeof(topts));
 586                topts.head_idx = -1;
 587                topts.src_index = &the_index;
 588                topts.dst_index = &the_index;
 589
 590                setup_unpack_trees_porcelain(&topts, "checkout");
 591
 592                refresh_cache(REFRESH_QUIET);
 593
 594                if (unmerged_cache()) {
 595                        error(_("you need to resolve your current index first"));
 596                        return 1;
 597                }
 598
 599                /* 2-way merge to the new branch */
 600                topts.initial_checkout = is_cache_unborn();
 601                topts.update = 1;
 602                topts.merge = 1;
 603                topts.gently = opts->merge && old_branch_info->commit;
 604                topts.verbose_update = opts->show_progress;
 605                topts.fn = twoway_merge;
 606                if (opts->overwrite_ignore) {
 607                        topts.dir = xcalloc(1, sizeof(*topts.dir));
 608                        topts.dir->flags |= DIR_SHOW_IGNORED;
 609                        setup_standard_excludes(topts.dir);
 610                }
 611                tree = parse_tree_indirect(old_branch_info->commit ?
 612                                           &old_branch_info->commit->object.oid :
 613                                           the_hash_algo->empty_tree);
 614                init_tree_desc(&trees[0], tree->buffer, tree->size);
 615                tree = parse_tree_indirect(&new_branch_info->commit->object.oid);
 616                init_tree_desc(&trees[1], tree->buffer, tree->size);
 617
 618                ret = unpack_trees(2, trees, &topts);
 619                clear_unpack_trees_porcelain(&topts);
 620                if (ret == -1) {
 621                        /*
 622                         * Unpack couldn't do a trivial merge; either
 623                         * give up or do a real merge, depending on
 624                         * whether the merge flag was used.
 625                         */
 626                        struct tree *result;
 627                        struct tree *work;
 628                        struct merge_options o;
 629                        if (!opts->merge)
 630                                return 1;
 631
 632                        /*
 633                         * Without old_branch_info->commit, the below is the same as
 634                         * the two-tree unpack we already tried and failed.
 635                         */
 636                        if (!old_branch_info->commit)
 637                                return 1;
 638
 639                        /* Do more real merge */
 640
 641                        /*
 642                         * We update the index fully, then write the
 643                         * tree from the index, then merge the new
 644                         * branch with the current tree, with the old
 645                         * branch as the base. Then we reset the index
 646                         * (but not the working tree) to the new
 647                         * branch, leaving the working tree as the
 648                         * merged version, but skipping unmerged
 649                         * entries in the index.
 650                         */
 651
 652                        add_files_to_cache(NULL, NULL, 0);
 653                        /*
 654                         * NEEDSWORK: carrying over local changes
 655                         * when branches have different end-of-line
 656                         * normalization (or clean+smudge rules) is
 657                         * a pain; plumb in an option to set
 658                         * o.renormalize?
 659                         */
 660                        init_merge_options(&o, the_repository);
 661                        o.verbosity = 0;
 662                        work = write_tree_from_memory(&o);
 663
 664                        ret = reset_tree(get_commit_tree(new_branch_info->commit),
 665                                         opts, 1,
 666                                         writeout_error);
 667                        if (ret)
 668                                return ret;
 669                        o.ancestor = old_branch_info->name;
 670                        o.branch1 = new_branch_info->name;
 671                        o.branch2 = "local";
 672                        ret = merge_trees(&o,
 673                                          get_commit_tree(new_branch_info->commit),
 674                                          work,
 675                                          get_commit_tree(old_branch_info->commit),
 676                                          &result);
 677                        if (ret < 0)
 678                                exit(128);
 679                        ret = reset_tree(get_commit_tree(new_branch_info->commit),
 680                                         opts, 0,
 681                                         writeout_error);
 682                        strbuf_release(&o.obuf);
 683                        if (ret)
 684                                return ret;
 685                }
 686        }
 687
 688        if (!active_cache_tree)
 689                active_cache_tree = cache_tree();
 690
 691        if (!cache_tree_fully_valid(active_cache_tree))
 692                cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
 693
 694        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 695                die(_("unable to write new index file"));
 696
 697        if (!opts->discard_changes && !opts->quiet)
 698                show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
 699
 700        return 0;
 701}
 702
 703static void report_tracking(struct branch_info *new_branch_info)
 704{
 705        struct strbuf sb = STRBUF_INIT;
 706        struct branch *branch = branch_get(new_branch_info->name);
 707
 708        if (!format_tracking_info(branch, &sb, AHEAD_BEHIND_FULL))
 709                return;
 710        fputs(sb.buf, stdout);
 711        strbuf_release(&sb);
 712}
 713
 714static void update_refs_for_switch(const struct checkout_opts *opts,
 715                                   struct branch_info *old_branch_info,
 716                                   struct branch_info *new_branch_info)
 717{
 718        struct strbuf msg = STRBUF_INIT;
 719        const char *old_desc, *reflog_msg;
 720        if (opts->new_branch) {
 721                if (opts->new_orphan_branch) {
 722                        char *refname;
 723
 724                        refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
 725                        if (opts->new_branch_log &&
 726                            !should_autocreate_reflog(refname)) {
 727                                int ret;
 728                                struct strbuf err = STRBUF_INIT;
 729
 730                                ret = safe_create_reflog(refname, 1, &err);
 731                                if (ret) {
 732                                        fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
 733                                                opts->new_orphan_branch, err.buf);
 734                                        strbuf_release(&err);
 735                                        free(refname);
 736                                        return;
 737                                }
 738                                strbuf_release(&err);
 739                        }
 740                        free(refname);
 741                }
 742                else
 743                        create_branch(the_repository,
 744                                      opts->new_branch, new_branch_info->name,
 745                                      opts->new_branch_force ? 1 : 0,
 746                                      opts->new_branch_force ? 1 : 0,
 747                                      opts->new_branch_log,
 748                                      opts->quiet,
 749                                      opts->track);
 750                new_branch_info->name = opts->new_branch;
 751                setup_branch_path(new_branch_info);
 752        }
 753
 754        old_desc = old_branch_info->name;
 755        if (!old_desc && old_branch_info->commit)
 756                old_desc = oid_to_hex(&old_branch_info->commit->object.oid);
 757
 758        reflog_msg = getenv("GIT_REFLOG_ACTION");
 759        if (!reflog_msg)
 760                strbuf_addf(&msg, "checkout: moving from %s to %s",
 761                        old_desc ? old_desc : "(invalid)", new_branch_info->name);
 762        else
 763                strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
 764
 765        if (!strcmp(new_branch_info->name, "HEAD") && !new_branch_info->path && !opts->force_detach) {
 766                /* Nothing to do. */
 767        } else if (opts->force_detach || !new_branch_info->path) {      /* No longer on any branch. */
 768                update_ref(msg.buf, "HEAD", &new_branch_info->commit->object.oid, NULL,
 769                           REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
 770                if (!opts->quiet) {
 771                        if (old_branch_info->path &&
 772                            advice_detached_head && !opts->force_detach)
 773                                detach_advice(new_branch_info->name);
 774                        describe_detached_head(_("HEAD is now at"), new_branch_info->commit);
 775                }
 776        } else if (new_branch_info->path) {     /* Switch branches. */
 777                if (create_symref("HEAD", new_branch_info->path, msg.buf) < 0)
 778                        die(_("unable to update HEAD"));
 779                if (!opts->quiet) {
 780                        if (old_branch_info->path && !strcmp(new_branch_info->path, old_branch_info->path)) {
 781                                if (opts->new_branch_force)
 782                                        fprintf(stderr, _("Reset branch '%s'\n"),
 783                                                new_branch_info->name);
 784                                else
 785                                        fprintf(stderr, _("Already on '%s'\n"),
 786                                                new_branch_info->name);
 787                        } else if (opts->new_branch) {
 788                                if (opts->branch_exists)
 789                                        fprintf(stderr, _("Switched to and reset branch '%s'\n"), new_branch_info->name);
 790                                else
 791                                        fprintf(stderr, _("Switched to a new branch '%s'\n"), new_branch_info->name);
 792                        } else {
 793                                fprintf(stderr, _("Switched to branch '%s'\n"),
 794                                        new_branch_info->name);
 795                        }
 796                }
 797                if (old_branch_info->path && old_branch_info->name) {
 798                        if (!ref_exists(old_branch_info->path) && reflog_exists(old_branch_info->path))
 799                                delete_reflog(old_branch_info->path);
 800                }
 801        }
 802        remove_branch_state(the_repository, !opts->quiet);
 803        strbuf_release(&msg);
 804        if (!opts->quiet &&
 805            (new_branch_info->path || (!opts->force_detach && !strcmp(new_branch_info->name, "HEAD"))))
 806                report_tracking(new_branch_info);
 807}
 808
 809static int add_pending_uninteresting_ref(const char *refname,
 810                                         const struct object_id *oid,
 811                                         int flags, void *cb_data)
 812{
 813        add_pending_oid(cb_data, refname, oid, UNINTERESTING);
 814        return 0;
 815}
 816
 817static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
 818{
 819        strbuf_addstr(sb, "  ");
 820        strbuf_add_unique_abbrev(sb, &commit->object.oid, DEFAULT_ABBREV);
 821        strbuf_addch(sb, ' ');
 822        if (!parse_commit(commit))
 823                pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
 824        strbuf_addch(sb, '\n');
 825}
 826
 827#define ORPHAN_CUTOFF 4
 828static void suggest_reattach(struct commit *commit, struct rev_info *revs)
 829{
 830        struct commit *c, *last = NULL;
 831        struct strbuf sb = STRBUF_INIT;
 832        int lost = 0;
 833        while ((c = get_revision(revs)) != NULL) {
 834                if (lost < ORPHAN_CUTOFF)
 835                        describe_one_orphan(&sb, c);
 836                last = c;
 837                lost++;
 838        }
 839        if (ORPHAN_CUTOFF < lost) {
 840                int more = lost - ORPHAN_CUTOFF;
 841                if (more == 1)
 842                        describe_one_orphan(&sb, last);
 843                else
 844                        strbuf_addf(&sb, _(" ... and %d more.\n"), more);
 845        }
 846
 847        fprintf(stderr,
 848                Q_(
 849                /* The singular version */
 850                "Warning: you are leaving %d commit behind, "
 851                "not connected to\n"
 852                "any of your branches:\n\n"
 853                "%s\n",
 854                /* The plural version */
 855                "Warning: you are leaving %d commits behind, "
 856                "not connected to\n"
 857                "any of your branches:\n\n"
 858                "%s\n",
 859                /* Give ngettext() the count */
 860                lost),
 861                lost,
 862                sb.buf);
 863        strbuf_release(&sb);
 864
 865        if (advice_detached_head)
 866                fprintf(stderr,
 867                        Q_(
 868                        /* The singular version */
 869                        "If you want to keep it by creating a new branch, "
 870                        "this may be a good time\nto do so with:\n\n"
 871                        " git branch <new-branch-name> %s\n\n",
 872                        /* The plural version */
 873                        "If you want to keep them by creating a new branch, "
 874                        "this may be a good time\nto do so with:\n\n"
 875                        " git branch <new-branch-name> %s\n\n",
 876                        /* Give ngettext() the count */
 877                        lost),
 878                        find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
 879}
 880
 881/*
 882 * We are about to leave commit that was at the tip of a detached
 883 * HEAD.  If it is not reachable from any ref, this is the last chance
 884 * for the user to do so without resorting to reflog.
 885 */
 886static void orphaned_commit_warning(struct commit *old_commit, struct commit *new_commit)
 887{
 888        struct rev_info revs;
 889        struct object *object = &old_commit->object;
 890
 891        repo_init_revisions(the_repository, &revs, NULL);
 892        setup_revisions(0, NULL, &revs, NULL);
 893
 894        object->flags &= ~UNINTERESTING;
 895        add_pending_object(&revs, object, oid_to_hex(&object->oid));
 896
 897        for_each_ref(add_pending_uninteresting_ref, &revs);
 898        add_pending_oid(&revs, "HEAD", &new_commit->object.oid, UNINTERESTING);
 899
 900        if (prepare_revision_walk(&revs))
 901                die(_("internal error in revision walk"));
 902        if (!(old_commit->object.flags & UNINTERESTING))
 903                suggest_reattach(old_commit, &revs);
 904        else
 905                describe_detached_head(_("Previous HEAD position was"), old_commit);
 906
 907        /* Clean up objects used, as they will be reused. */
 908        clear_commit_marks_all(ALL_REV_FLAGS);
 909}
 910
 911static int switch_branches(const struct checkout_opts *opts,
 912                           struct branch_info *new_branch_info)
 913{
 914        int ret = 0;
 915        struct branch_info old_branch_info;
 916        void *path_to_free;
 917        struct object_id rev;
 918        int flag, writeout_error = 0;
 919        int do_merge = 1;
 920
 921        trace2_cmd_mode("branch");
 922
 923        memset(&old_branch_info, 0, sizeof(old_branch_info));
 924        old_branch_info.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
 925        if (old_branch_info.path)
 926                old_branch_info.commit = lookup_commit_reference_gently(the_repository, &rev, 1);
 927        if (!(flag & REF_ISSYMREF))
 928                old_branch_info.path = NULL;
 929
 930        if (old_branch_info.path)
 931                skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name);
 932
 933        if (!new_branch_info->name) {
 934                new_branch_info->name = "HEAD";
 935                new_branch_info->commit = old_branch_info.commit;
 936                if (!new_branch_info->commit)
 937                        die(_("You are on a branch yet to be born"));
 938                parse_commit_or_die(new_branch_info->commit);
 939
 940                if (opts->only_merge_on_switching_branches)
 941                        do_merge = 0;
 942        }
 943
 944        if (do_merge) {
 945                ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
 946                if (ret) {
 947                        free(path_to_free);
 948                        return ret;
 949                }
 950        }
 951
 952        if (!opts->quiet && !old_branch_info.path && old_branch_info.commit && new_branch_info->commit != old_branch_info.commit)
 953                orphaned_commit_warning(old_branch_info.commit, new_branch_info->commit);
 954
 955        update_refs_for_switch(opts, &old_branch_info, new_branch_info);
 956
 957        ret = post_checkout_hook(old_branch_info.commit, new_branch_info->commit, 1);
 958        free(path_to_free);
 959        return ret || writeout_error;
 960}
 961
 962static int git_checkout_config(const char *var, const char *value, void *cb)
 963{
 964        if (!strcmp(var, "diff.ignoresubmodules")) {
 965                struct checkout_opts *opts = cb;
 966                handle_ignore_submodules_arg(&opts->diff_options, value);
 967                return 0;
 968        }
 969
 970        if (starts_with(var, "submodule."))
 971                return git_default_submodule_config(var, value, NULL);
 972
 973        return git_xmerge_config(var, value, NULL);
 974}
 975
 976static void setup_new_branch_info_and_source_tree(
 977        struct branch_info *new_branch_info,
 978        struct checkout_opts *opts,
 979        struct object_id *rev,
 980        const char *arg)
 981{
 982        struct tree **source_tree = &opts->source_tree;
 983        struct object_id branch_rev;
 984
 985        new_branch_info->name = arg;
 986        setup_branch_path(new_branch_info);
 987
 988        if (!check_refname_format(new_branch_info->path, 0) &&
 989            !read_ref(new_branch_info->path, &branch_rev))
 990                oidcpy(rev, &branch_rev);
 991        else
 992                new_branch_info->path = NULL; /* not an existing branch */
 993
 994        new_branch_info->commit = lookup_commit_reference_gently(the_repository, rev, 1);
 995        if (!new_branch_info->commit) {
 996                /* not a commit */
 997                *source_tree = parse_tree_indirect(rev);
 998        } else {
 999                parse_commit_or_die(new_branch_info->commit);
1000                *source_tree = get_commit_tree(new_branch_info->commit);
1001        }
1002}
1003
1004static int parse_branchname_arg(int argc, const char **argv,
1005                                int dwim_new_local_branch_ok,
1006                                struct branch_info *new_branch_info,
1007                                struct checkout_opts *opts,
1008                                struct object_id *rev,
1009                                int *dwim_remotes_matched)
1010{
1011        const char **new_branch = &opts->new_branch;
1012        int argcount = 0;
1013        const char *arg;
1014        int dash_dash_pos;
1015        int has_dash_dash = 0;
1016        int i;
1017
1018        /*
1019         * case 1: git checkout <ref> -- [<paths>]
1020         *
1021         *   <ref> must be a valid tree, everything after the '--' must be
1022         *   a path.
1023         *
1024         * case 2: git checkout -- [<paths>]
1025         *
1026         *   everything after the '--' must be paths.
1027         *
1028         * case 3: git checkout <something> [--]
1029         *
1030         *   (a) If <something> is a commit, that is to
1031         *       switch to the branch or detach HEAD at it.  As a special case,
1032         *       if <something> is A...B (missing A or B means HEAD but you can
1033         *       omit at most one side), and if there is a unique merge base
1034         *       between A and B, A...B names that merge base.
1035         *
1036         *   (b) If <something> is _not_ a commit, either "--" is present
1037         *       or <something> is not a path, no -t or -b was given, and
1038         *       and there is a tracking branch whose name is <something>
1039         *       in one and only one remote (or if the branch exists on the
1040         *       remote named in checkout.defaultRemote), then this is a
1041         *       short-hand to fork local <something> from that
1042         *       remote-tracking branch.
1043         *
1044         *   (c) Otherwise, if "--" is present, treat it like case (1).
1045         *
1046         *   (d) Otherwise :
1047         *       - if it's a reference, treat it like case (1)
1048         *       - else if it's a path, treat it like case (2)
1049         *       - else: fail.
1050         *
1051         * case 4: git checkout <something> <paths>
1052         *
1053         *   The first argument must not be ambiguous.
1054         *   - If it's *only* a reference, treat it like case (1).
1055         *   - If it's only a path, treat it like case (2).
1056         *   - else: fail.
1057         *
1058         */
1059        if (!argc)
1060                return 0;
1061
1062        if (!opts->accept_pathspec) {
1063                if (argc > 1)
1064                        die(_("only one reference expected"));
1065                has_dash_dash = 1; /* helps disambiguate */
1066        }
1067
1068        arg = argv[0];
1069        dash_dash_pos = -1;
1070        for (i = 0; i < argc; i++) {
1071                if (opts->accept_pathspec && !strcmp(argv[i], "--")) {
1072                        dash_dash_pos = i;
1073                        break;
1074                }
1075        }
1076        if (dash_dash_pos == 0)
1077                return 1; /* case (2) */
1078        else if (dash_dash_pos == 1)
1079                has_dash_dash = 1; /* case (3) or (1) */
1080        else if (dash_dash_pos >= 2)
1081                die(_("only one reference expected, %d given."), dash_dash_pos);
1082        opts->count_checkout_paths = !opts->quiet && !has_dash_dash;
1083
1084        if (!strcmp(arg, "-"))
1085                arg = "@{-1}";
1086
1087        if (get_oid_mb(arg, rev)) {
1088                /*
1089                 * Either case (3) or (4), with <something> not being
1090                 * a commit, or an attempt to use case (1) with an
1091                 * invalid ref.
1092                 *
1093                 * It's likely an error, but we need to find out if
1094                 * we should auto-create the branch, case (3).(b).
1095                 */
1096                int recover_with_dwim = dwim_new_local_branch_ok;
1097
1098                int could_be_checkout_paths = !has_dash_dash &&
1099                        check_filename(opts->prefix, arg);
1100
1101                if (!has_dash_dash && !no_wildcard(arg))
1102                        recover_with_dwim = 0;
1103
1104                /*
1105                 * Accept "git checkout foo", "git checkout foo --"
1106                 * and "git switch foo" as candidates for dwim.
1107                 */
1108                if (!(argc == 1 && !has_dash_dash) &&
1109                    !(argc == 2 && has_dash_dash) &&
1110                    opts->accept_pathspec)
1111                        recover_with_dwim = 0;
1112
1113                if (recover_with_dwim) {
1114                        const char *remote = unique_tracking_name(arg, rev,
1115                                                                  dwim_remotes_matched);
1116                        if (remote) {
1117                                if (could_be_checkout_paths)
1118                                        die(_("'%s' could be both a local file and a tracking branch.\n"
1119                                              "Please use -- (and optionally --no-guess) to disambiguate"),
1120                                            arg);
1121                                *new_branch = arg;
1122                                arg = remote;
1123                                /* DWIMmed to create local branch, case (3).(b) */
1124                        } else {
1125                                recover_with_dwim = 0;
1126                        }
1127                }
1128
1129                if (!recover_with_dwim) {
1130                        if (has_dash_dash)
1131                                die(_("invalid reference: %s"), arg);
1132                        return argcount;
1133                }
1134        }
1135
1136        /* we can't end up being in (2) anymore, eat the argument */
1137        argcount++;
1138        argv++;
1139        argc--;
1140
1141        setup_new_branch_info_and_source_tree(new_branch_info, opts, rev, arg);
1142
1143        if (!opts->source_tree)                   /* case (1): want a tree */
1144                die(_("reference is not a tree: %s"), arg);
1145
1146        if (!has_dash_dash) {   /* case (3).(d) -> (1) */
1147                /*
1148                 * Do not complain the most common case
1149                 *      git checkout branch
1150                 * even if there happen to be a file called 'branch';
1151                 * it would be extremely annoying.
1152                 */
1153                if (argc)
1154                        verify_non_filename(opts->prefix, arg);
1155        } else if (opts->accept_pathspec) {
1156                argcount++;
1157                argv++;
1158                argc--;
1159        }
1160
1161        return argcount;
1162}
1163
1164static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1165{
1166        int status;
1167        struct strbuf branch_ref = STRBUF_INIT;
1168
1169        trace2_cmd_mode("unborn");
1170
1171        if (!opts->new_branch)
1172                die(_("You are on a branch yet to be born"));
1173        strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1174        status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1175        strbuf_release(&branch_ref);
1176        if (!opts->quiet)
1177                fprintf(stderr, _("Switched to a new branch '%s'\n"),
1178                        opts->new_branch);
1179        return status;
1180}
1181
1182static void die_expecting_a_branch(const struct branch_info *branch_info)
1183{
1184        struct object_id oid;
1185        char *to_free;
1186
1187        if (dwim_ref(branch_info->name, strlen(branch_info->name), &oid, &to_free) == 1) {
1188                const char *ref = to_free;
1189
1190                if (skip_prefix(ref, "refs/tags/", &ref))
1191                        die(_("a branch is expected, got tag '%s'"), ref);
1192                if (skip_prefix(ref, "refs/remotes/", &ref))
1193                        die(_("a branch is expected, got remote branch '%s'"), ref);
1194                die(_("a branch is expected, got '%s'"), ref);
1195        }
1196        if (branch_info->commit)
1197                die(_("a branch is expected, got commit '%s'"), branch_info->name);
1198        /*
1199         * This case should never happen because we already die() on
1200         * non-commit, but just in case.
1201         */
1202        die(_("a branch is expected, got '%s'"), branch_info->name);
1203}
1204
1205static int checkout_branch(struct checkout_opts *opts,
1206                           struct branch_info *new_branch_info)
1207{
1208        if (opts->pathspec.nr)
1209                die(_("paths cannot be used with switching branches"));
1210
1211        if (opts->patch_mode)
1212                die(_("'%s' cannot be used with switching branches"),
1213                    "--patch");
1214
1215        if (!opts->overlay_mode)
1216                die(_("'%s' cannot be used with switching branches"),
1217                    "--no-overlay");
1218
1219        if (opts->writeout_stage)
1220                die(_("'%s' cannot be used with switching branches"),
1221                    "--ours/--theirs");
1222
1223        if (opts->force && opts->merge)
1224                die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1225
1226        if (opts->discard_changes && opts->merge)
1227                die(_("'%s' cannot be used with '%s'"), "--discard-changes", "--merge");
1228
1229        if (opts->force_detach && opts->new_branch)
1230                die(_("'%s' cannot be used with '%s'"),
1231                    "--detach", "-b/-B/--orphan");
1232
1233        if (opts->new_orphan_branch) {
1234                if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1235                        die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1236        } else if (opts->force_detach) {
1237                if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1238                        die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1239        } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1240                opts->track = git_branch_track;
1241
1242        if (new_branch_info->name && !new_branch_info->commit)
1243                die(_("Cannot switch branch to a non-commit '%s'"),
1244                    new_branch_info->name);
1245
1246        if (!opts->switch_branch_doing_nothing_is_ok &&
1247            !new_branch_info->name &&
1248            !opts->new_branch &&
1249            !opts->force_detach)
1250                die(_("missing branch or commit argument"));
1251
1252        if (!opts->implicit_detach &&
1253            !opts->force_detach &&
1254            !opts->new_branch &&
1255            !opts->new_branch_force &&
1256            new_branch_info->name &&
1257            !new_branch_info->path)
1258                die_expecting_a_branch(new_branch_info);
1259
1260        if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
1261            !opts->ignore_other_worktrees) {
1262                int flag;
1263                char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
1264                if (head_ref &&
1265                    (!(flag & REF_ISSYMREF) || strcmp(head_ref, new_branch_info->path)))
1266                        die_if_checked_out(new_branch_info->path, 1);
1267                free(head_ref);
1268        }
1269
1270        if (!new_branch_info->commit && opts->new_branch) {
1271                struct object_id rev;
1272                int flag;
1273
1274                if (!read_ref_full("HEAD", 0, &rev, &flag) &&
1275                    (flag & REF_ISSYMREF) && is_null_oid(&rev))
1276                        return switch_unborn_to_new_branch(opts);
1277        }
1278        return switch_branches(opts, new_branch_info);
1279}
1280
1281static struct option *add_common_options(struct checkout_opts *opts,
1282                                         struct option *prevopts)
1283{
1284        struct option options[] = {
1285                OPT__QUIET(&opts->quiet, N_("suppress progress reporting")),
1286                { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
1287                            "checkout", "control recursive updating of submodules",
1288                            PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
1289                OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
1290                OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
1291                           PARSE_OPT_NOCOMPLETE),
1292                OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
1293                OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
1294                           N_("conflict style (merge or diff3)")),
1295                OPT_END()
1296        };
1297        struct option *newopts = parse_options_concat(prevopts, options);
1298        free(prevopts);
1299        return newopts;
1300}
1301
1302static struct option *add_common_switch_branch_options(
1303        struct checkout_opts *opts, struct option *prevopts)
1304{
1305        struct option options[] = {
1306                OPT_BOOL('d', "detach", &opts->force_detach, N_("detach HEAD at named commit")),
1307                OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
1308                        BRANCH_TRACK_EXPLICIT),
1309                OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1310                OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
1311                           N_("update ignored files (default)"),
1312                           PARSE_OPT_NOCOMPLETE),
1313                OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
1314                         N_("do not check if another worktree is holding the given ref")),
1315                OPT_END()
1316        };
1317        struct option *newopts = parse_options_concat(prevopts, options);
1318        free(prevopts);
1319        return newopts;
1320}
1321
1322static struct option *add_checkout_path_options(struct checkout_opts *opts,
1323                                                struct option *prevopts)
1324{
1325        struct option options[] = {
1326                OPT_SET_INT_F('2', "ours", &opts->writeout_stage,
1327                              N_("checkout our version for unmerged files"),
1328                              2, PARSE_OPT_NONEG),
1329                OPT_SET_INT_F('3', "theirs", &opts->writeout_stage,
1330                              N_("checkout their version for unmerged files"),
1331                              3, PARSE_OPT_NONEG),
1332                OPT_BOOL('p', "patch", &opts->patch_mode, N_("select hunks interactively")),
1333                OPT_BOOL(0, "ignore-skip-worktree-bits", &opts->ignore_skipworktree,
1334                         N_("do not limit pathspecs to sparse entries only")),
1335                OPT_BOOL(0, "overlay", &opts->overlay_mode, N_("use overlay mode (default)")),
1336                OPT_END()
1337        };
1338        struct option *newopts = parse_options_concat(prevopts, options);
1339        free(prevopts);
1340        return newopts;
1341}
1342
1343static int checkout_main(int argc, const char **argv, const char *prefix,
1344                         struct checkout_opts *opts, struct option *options,
1345                         const char * const usagestr[])
1346{
1347        struct branch_info new_branch_info;
1348        int dwim_remotes_matched = 0;
1349
1350        memset(&new_branch_info, 0, sizeof(new_branch_info));
1351        opts->overwrite_ignore = 1;
1352        opts->prefix = prefix;
1353        opts->show_progress = -1;
1354        opts->overlay_mode = -1;
1355
1356        git_config(git_checkout_config, opts);
1357
1358        opts->track = BRANCH_TRACK_UNSPECIFIED;
1359
1360        argc = parse_options(argc, argv, prefix, options, usagestr,
1361                             PARSE_OPT_KEEP_DASHDASH);
1362
1363        if (opts->show_progress < 0) {
1364                if (opts->quiet)
1365                        opts->show_progress = 0;
1366                else
1367                        opts->show_progress = isatty(2);
1368        }
1369
1370        if (opts->conflict_style) {
1371                opts->merge = 1; /* implied */
1372                git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL);
1373        }
1374        if (opts->force)
1375                opts->discard_changes = 1;
1376
1377        if ((!!opts->new_branch + !!opts->new_branch_force + !!opts->new_orphan_branch) > 1)
1378                die(_("-b, -B and --orphan are mutually exclusive"));
1379
1380        if (opts->overlay_mode == 1 && opts->patch_mode)
1381                die(_("-p and --overlay are mutually exclusive"));
1382
1383        /*
1384         * From here on, new_branch will contain the branch to be checked out,
1385         * and new_branch_force and new_orphan_branch will tell us which one of
1386         * -b/-B/--orphan is being used.
1387         */
1388        if (opts->new_branch_force)
1389                opts->new_branch = opts->new_branch_force;
1390
1391        if (opts->new_orphan_branch)
1392                opts->new_branch = opts->new_orphan_branch;
1393
1394        /* --track without -b/-B/--orphan should DWIM */
1395        if (opts->track != BRANCH_TRACK_UNSPECIFIED && !opts->new_branch) {
1396                const char *argv0 = argv[0];
1397                if (!argc || !strcmp(argv0, "--"))
1398                        die(_("--track needs a branch name"));
1399                skip_prefix(argv0, "refs/", &argv0);
1400                skip_prefix(argv0, "remotes/", &argv0);
1401                argv0 = strchr(argv0, '/');
1402                if (!argv0 || !argv0[1])
1403                        die(_("missing branch name; try -b"));
1404                opts->new_branch = argv0 + 1;
1405        }
1406
1407        /*
1408         * Extract branch name from command line arguments, so
1409         * all that is left is pathspecs.
1410         *
1411         * Handle
1412         *
1413         *  1) git checkout <tree> -- [<paths>]
1414         *  2) git checkout -- [<paths>]
1415         *  3) git checkout <something> [<paths>]
1416         *
1417         * including "last branch" syntax and DWIM-ery for names of
1418         * remote branches, erroring out for invalid or ambiguous cases.
1419         */
1420        if (argc) {
1421                struct object_id rev;
1422                int dwim_ok =
1423                        !opts->patch_mode &&
1424                        opts->dwim_new_local_branch &&
1425                        opts->track == BRANCH_TRACK_UNSPECIFIED &&
1426                        !opts->new_branch;
1427                int n = parse_branchname_arg(argc, argv, dwim_ok,
1428                                             &new_branch_info, opts, &rev,
1429                                             &dwim_remotes_matched);
1430                argv += n;
1431                argc -= n;
1432        }
1433
1434        if (argc) {
1435                parse_pathspec(&opts->pathspec, 0,
1436                               opts->patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1437                               prefix, argv);
1438
1439                if (!opts->pathspec.nr)
1440                        die(_("invalid path specification"));
1441
1442                /*
1443                 * Try to give more helpful suggestion.
1444                 * new_branch && argc > 1 will be caught later.
1445                 */
1446                if (opts->new_branch && argc == 1)
1447                        die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1448                                argv[0], opts->new_branch);
1449
1450                if (opts->force_detach)
1451                        die(_("git checkout: --detach does not take a path argument '%s'"),
1452                            argv[0]);
1453
1454                if (1 < !!opts->writeout_stage + !!opts->force + !!opts->merge)
1455                        die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1456                              "checking out of the index."));
1457        }
1458
1459        if (opts->new_branch) {
1460                struct strbuf buf = STRBUF_INIT;
1461
1462                if (opts->new_branch_force)
1463                        opts->branch_exists = validate_branchname(opts->new_branch, &buf);
1464                else
1465                        opts->branch_exists =
1466                                validate_new_branchname(opts->new_branch, &buf, 0);
1467                strbuf_release(&buf);
1468        }
1469
1470        UNLEAK(opts);
1471        if (opts->patch_mode || opts->pathspec.nr) {
1472                int ret = checkout_paths(opts, new_branch_info.name);
1473                if (ret && dwim_remotes_matched > 1 &&
1474                    advice_checkout_ambiguous_remote_branch_name)
1475                        advise(_("'%s' matched more than one remote tracking branch.\n"
1476                                 "We found %d remotes with a reference that matched. So we fell back\n"
1477                                 "on trying to resolve the argument as a path, but failed there too!\n"
1478                                 "\n"
1479                                 "If you meant to check out a remote tracking branch on, e.g. 'origin',\n"
1480                                 "you can do so by fully qualifying the name with the --track option:\n"
1481                                 "\n"
1482                                 "    git checkout --track origin/<name>\n"
1483                                 "\n"
1484                                 "If you'd like to always have checkouts of an ambiguous <name> prefer\n"
1485                                 "one remote, e.g. the 'origin' remote, consider setting\n"
1486                                 "checkout.defaultRemote=origin in your config."),
1487                               argv[0],
1488                               dwim_remotes_matched);
1489                return ret;
1490        } else {
1491                return checkout_branch(opts, &new_branch_info);
1492        }
1493}
1494
1495int cmd_checkout(int argc, const char **argv, const char *prefix)
1496{
1497        struct checkout_opts opts;
1498        struct option *options;
1499        struct option checkout_options[] = {
1500                OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1501                           N_("create and checkout a new branch")),
1502                OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1503                           N_("create/reset and checkout a branch")),
1504                OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1505                OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
1506                         N_("second guess 'git checkout <no-such-branch>' (default)")),
1507                OPT_END()
1508        };
1509        int ret;
1510
1511        memset(&opts, 0, sizeof(opts));
1512        opts.dwim_new_local_branch = 1;
1513        opts.switch_branch_doing_nothing_is_ok = 1;
1514        opts.only_merge_on_switching_branches = 0;
1515        opts.accept_pathspec = 1;
1516        opts.implicit_detach = 1;
1517
1518        options = parse_options_dup(checkout_options);
1519        options = add_common_options(&opts, options);
1520        options = add_common_switch_branch_options(&opts, options);
1521        options = add_checkout_path_options(&opts, options);
1522
1523        ret = checkout_main(argc, argv, prefix, &opts,
1524                            options, checkout_usage);
1525        FREE_AND_NULL(options);
1526        return ret;
1527}
1528
1529int cmd_switch(int argc, const char **argv, const char *prefix)
1530{
1531        struct checkout_opts opts;
1532        struct option *options = NULL;
1533        struct option switch_options[] = {
1534                OPT_STRING('c', "create", &opts.new_branch, N_("branch"),
1535                           N_("create and switch to a new branch")),
1536                OPT_STRING('C', "force-create", &opts.new_branch_force, N_("branch"),
1537                           N_("create/reset and switch to a branch")),
1538                OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
1539                         N_("second guess 'git switch <no-such-branch>'")),
1540                OPT_BOOL(0, "discard-changes", &opts.discard_changes,
1541                         N_("throw away local modifications")),
1542                OPT_END()
1543        };
1544        int ret;
1545
1546        memset(&opts, 0, sizeof(opts));
1547        opts.dwim_new_local_branch = 1;
1548        opts.accept_pathspec = 0;
1549        opts.switch_branch_doing_nothing_is_ok = 0;
1550        opts.only_merge_on_switching_branches = 1;
1551        opts.implicit_detach = 0;
1552
1553        options = parse_options_dup(switch_options);
1554        options = add_common_options(&opts, options);
1555        options = add_common_switch_branch_options(&opts, options);
1556
1557        ret = checkout_main(argc, argv, prefix, &opts,
1558                            options, switch_branch_usage);
1559        FREE_AND_NULL(options);
1560        return ret;
1561}