builtin-checkout.con commit t0050: Fix merge test on case sensitive file systems (0047dd2)
   1#include "cache.h"
   2#include "builtin.h"
   3#include "parse-options.h"
   4#include "refs.h"
   5#include "commit.h"
   6#include "tree.h"
   7#include "tree-walk.h"
   8#include "unpack-trees.h"
   9#include "dir.h"
  10#include "run-command.h"
  11#include "merge-recursive.h"
  12#include "branch.h"
  13#include "diff.h"
  14#include "revision.h"
  15#include "remote.h"
  16
  17static const char * const checkout_usage[] = {
  18        "git checkout [options] <branch>",
  19        "git checkout [options] [<branch>] -- <file>...",
  20        NULL,
  21};
  22
  23static int post_checkout_hook(struct commit *old, struct commit *new,
  24                              int changed)
  25{
  26        struct child_process proc;
  27        const char *name = git_path("hooks/post-checkout");
  28        const char *argv[5];
  29
  30        if (access(name, X_OK) < 0)
  31                return 0;
  32
  33        memset(&proc, 0, sizeof(proc));
  34        argv[0] = name;
  35        argv[1] = xstrdup(sha1_to_hex(old->object.sha1));
  36        argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
  37        argv[3] = changed ? "1" : "0";
  38        argv[4] = NULL;
  39        proc.argv = argv;
  40        proc.no_stdin = 1;
  41        proc.stdout_to_stderr = 1;
  42        return run_command(&proc);
  43}
  44
  45static int update_some(const unsigned char *sha1, const char *base, int baselen,
  46                       const char *pathname, unsigned mode, int stage)
  47{
  48        int len;
  49        struct cache_entry *ce;
  50
  51        if (S_ISGITLINK(mode))
  52                return 0;
  53
  54        if (S_ISDIR(mode))
  55                return READ_TREE_RECURSIVE;
  56
  57        len = baselen + strlen(pathname);
  58        ce = xcalloc(1, cache_entry_size(len));
  59        hashcpy(ce->sha1, sha1);
  60        memcpy(ce->name, base, baselen);
  61        memcpy(ce->name + baselen, pathname, len - baselen);
  62        ce->ce_flags = create_ce_flags(len, 0);
  63        ce->ce_mode = create_ce_mode(mode);
  64        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
  65        return 0;
  66}
  67
  68static int read_tree_some(struct tree *tree, const char **pathspec)
  69{
  70        read_tree_recursive(tree, "", 0, 0, pathspec, update_some);
  71
  72        /* update the index with the given tree's info
  73         * for all args, expanding wildcards, and exit
  74         * with any non-zero return code.
  75         */
  76        return 0;
  77}
  78
  79static int checkout_paths(struct tree *source_tree, const char **pathspec)
  80{
  81        int pos;
  82        struct checkout state;
  83        static char *ps_matched;
  84        unsigned char rev[20];
  85        int flag;
  86        struct commit *head;
  87
  88        int newfd;
  89        struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
  90
  91        newfd = hold_locked_index(lock_file, 1);
  92        read_cache();
  93
  94        if (source_tree)
  95                read_tree_some(source_tree, pathspec);
  96
  97        for (pos = 0; pathspec[pos]; pos++)
  98                ;
  99        ps_matched = xcalloc(1, pos);
 100
 101        for (pos = 0; pos < active_nr; pos++) {
 102                struct cache_entry *ce = active_cache[pos];
 103                pathspec_match(pathspec, ps_matched, ce->name, 0);
 104        }
 105
 106        if (report_path_error(ps_matched, pathspec, 0))
 107                return 1;
 108
 109        memset(&state, 0, sizeof(state));
 110        state.force = 1;
 111        state.refresh_cache = 1;
 112        for (pos = 0; pos < active_nr; pos++) {
 113                struct cache_entry *ce = active_cache[pos];
 114                if (pathspec_match(pathspec, NULL, ce->name, 0)) {
 115                        checkout_entry(ce, &state, NULL);
 116                }
 117        }
 118
 119        if (write_cache(newfd, active_cache, active_nr) ||
 120            commit_locked_index(lock_file))
 121                die("unable to write new index file");
 122
 123        resolve_ref("HEAD", rev, 0, &flag);
 124        head = lookup_commit_reference_gently(rev, 1);
 125
 126        return post_checkout_hook(head, head, 0);
 127}
 128
 129static void show_local_changes(struct object *head)
 130{
 131        struct rev_info rev;
 132        /* I think we want full paths, even if we're in a subdirectory. */
 133        init_revisions(&rev, NULL);
 134        rev.abbrev = 0;
 135        rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
 136        add_pending_object(&rev, head, NULL);
 137        run_diff_index(&rev, 0);
 138}
 139
 140static void describe_detached_head(char *msg, struct commit *commit)
 141{
 142        struct strbuf sb;
 143        strbuf_init(&sb, 0);
 144        parse_commit(commit);
 145        pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
 146        fprintf(stderr, "%s %s... %s\n", msg,
 147                find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
 148        strbuf_release(&sb);
 149}
 150
 151static int reset_to_new(struct tree *tree, int quiet)
 152{
 153        struct unpack_trees_options opts;
 154        struct tree_desc tree_desc;
 155
 156        memset(&opts, 0, sizeof(opts));
 157        opts.head_idx = -1;
 158        opts.update = 1;
 159        opts.reset = 1;
 160        opts.merge = 1;
 161        opts.fn = oneway_merge;
 162        opts.verbose_update = !quiet;
 163        opts.src_index = &the_index;
 164        opts.dst_index = &the_index;
 165        parse_tree(tree);
 166        init_tree_desc(&tree_desc, tree->buffer, tree->size);
 167        if (unpack_trees(1, &tree_desc, &opts))
 168                return 128;
 169        return 0;
 170}
 171
 172static void reset_clean_to_new(struct tree *tree, int quiet)
 173{
 174        struct unpack_trees_options opts;
 175        struct tree_desc tree_desc;
 176
 177        memset(&opts, 0, sizeof(opts));
 178        opts.head_idx = -1;
 179        opts.skip_unmerged = 1;
 180        opts.reset = 1;
 181        opts.merge = 1;
 182        opts.fn = oneway_merge;
 183        opts.verbose_update = !quiet;
 184        opts.src_index = &the_index;
 185        opts.dst_index = &the_index;
 186        parse_tree(tree);
 187        init_tree_desc(&tree_desc, tree->buffer, tree->size);
 188        if (unpack_trees(1, &tree_desc, &opts))
 189                exit(128);
 190}
 191
 192struct checkout_opts {
 193        int quiet;
 194        int merge;
 195        int force;
 196
 197        char *new_branch;
 198        int new_branch_log;
 199        enum branch_track track;
 200};
 201
 202struct branch_info {
 203        const char *name; /* The short name used */
 204        const char *path; /* The full name of a real branch */
 205        struct commit *commit; /* The named commit */
 206};
 207
 208static void setup_branch_path(struct branch_info *branch)
 209{
 210        struct strbuf buf;
 211        strbuf_init(&buf, 0);
 212        strbuf_addstr(&buf, "refs/heads/");
 213        strbuf_addstr(&buf, branch->name);
 214        branch->path = strbuf_detach(&buf, NULL);
 215}
 216
 217static int merge_working_tree(struct checkout_opts *opts,
 218                              struct branch_info *old, struct branch_info *new)
 219{
 220        int ret;
 221        struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 222        int newfd = hold_locked_index(lock_file, 1);
 223        read_cache();
 224
 225        if (opts->force) {
 226                ret = reset_to_new(new->commit->tree, opts->quiet);
 227                if (ret)
 228                        return ret;
 229        } else {
 230                struct tree_desc trees[2];
 231                struct tree *tree;
 232                struct unpack_trees_options topts;
 233
 234                memset(&topts, 0, sizeof(topts));
 235                topts.head_idx = -1;
 236                topts.src_index = &the_index;
 237                topts.dst_index = &the_index;
 238
 239                refresh_cache(REFRESH_QUIET);
 240
 241                if (unmerged_cache()) {
 242                        error("you need to resolve your current index first");
 243                        return 1;
 244                }
 245
 246                /* 2-way merge to the new branch */
 247                topts.update = 1;
 248                topts.merge = 1;
 249                topts.gently = opts->merge;
 250                topts.verbose_update = !opts->quiet;
 251                topts.fn = twoway_merge;
 252                topts.dir = xcalloc(1, sizeof(*topts.dir));
 253                topts.dir->show_ignored = 1;
 254                topts.dir->exclude_per_dir = ".gitignore";
 255                tree = parse_tree_indirect(old->commit->object.sha1);
 256                init_tree_desc(&trees[0], tree->buffer, tree->size);
 257                tree = parse_tree_indirect(new->commit->object.sha1);
 258                init_tree_desc(&trees[1], tree->buffer, tree->size);
 259
 260                if (unpack_trees(2, trees, &topts)) {
 261                        /*
 262                         * Unpack couldn't do a trivial merge; either
 263                         * give up or do a real merge, depending on
 264                         * whether the merge flag was used.
 265                         */
 266                        struct tree *result;
 267                        struct tree *work;
 268                        if (!opts->merge)
 269                                return 1;
 270                        parse_commit(old->commit);
 271
 272                        /* Do more real merge */
 273
 274                        /*
 275                         * We update the index fully, then write the
 276                         * tree from the index, then merge the new
 277                         * branch with the current tree, with the old
 278                         * branch as the base. Then we reset the index
 279                         * (but not the working tree) to the new
 280                         * branch, leaving the working tree as the
 281                         * merged version, but skipping unmerged
 282                         * entries in the index.
 283                         */
 284
 285                        add_files_to_cache(0, NULL, NULL);
 286                        work = write_tree_from_memory();
 287
 288                        ret = reset_to_new(new->commit->tree, opts->quiet);
 289                        if (ret)
 290                                return ret;
 291                        merge_trees(new->commit->tree, work, old->commit->tree,
 292                                    new->name, "local", &result);
 293                        reset_clean_to_new(new->commit->tree, opts->quiet);
 294                }
 295        }
 296
 297        if (write_cache(newfd, active_cache, active_nr) ||
 298            commit_locked_index(lock_file))
 299                die("unable to write new index file");
 300
 301        if (!opts->force)
 302                show_local_changes(&new->commit->object);
 303
 304        return 0;
 305}
 306
 307static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
 308{
 309        /*
 310         * We have switched to a new branch; is it building on
 311         * top of another branch, and if so does that other branch
 312         * have changes we do not have yet?
 313         */
 314        char *base;
 315        unsigned char sha1[20];
 316        struct commit *ours, *theirs;
 317        char symmetric[84];
 318        struct rev_info revs;
 319        const char *rev_argv[10];
 320        int rev_argc;
 321        int num_ours, num_theirs;
 322        const char *remote_msg;
 323        struct branch *branch = branch_get(new->name);
 324
 325        /*
 326         * Nothing to report unless we are marked to build on top of
 327         * somebody else.
 328         */
 329        if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
 330                return;
 331
 332        /*
 333         * If what we used to build on no longer exists, there is
 334         * nothing to report.
 335         */
 336        base = branch->merge[0]->dst;
 337        if (!resolve_ref(base, sha1, 1, NULL))
 338                return;
 339
 340        theirs = lookup_commit(sha1);
 341        ours = new->commit;
 342        if (!hashcmp(sha1, ours->object.sha1))
 343                return; /* we are the same */
 344
 345        /* Run "rev-list --left-right ours...theirs" internally... */
 346        rev_argc = 0;
 347        rev_argv[rev_argc++] = NULL;
 348        rev_argv[rev_argc++] = "--left-right";
 349        rev_argv[rev_argc++] = symmetric;
 350        rev_argv[rev_argc++] = "--";
 351        rev_argv[rev_argc] = NULL;
 352
 353        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
 354        strcpy(symmetric + 40, "...");
 355        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
 356
 357        init_revisions(&revs, NULL);
 358        setup_revisions(rev_argc, rev_argv, &revs, NULL);
 359        prepare_revision_walk(&revs);
 360
 361        /* ... and count the commits on each side. */
 362        num_ours = 0;
 363        num_theirs = 0;
 364        while (1) {
 365                struct commit *c = get_revision(&revs);
 366                if (!c)
 367                        break;
 368                if (c->object.flags & SYMMETRIC_LEFT)
 369                        num_ours++;
 370                else
 371                        num_theirs++;
 372        }
 373
 374        if (!prefixcmp(base, "refs/remotes/")) {
 375                remote_msg = " remote";
 376                base += strlen("refs/remotes/");
 377        } else {
 378                remote_msg = "";
 379        }
 380
 381        if (!num_theirs)
 382                printf("Your branch is ahead of the tracked%s branch '%s' "
 383                       "by %d commit%s.\n",
 384                       remote_msg, base,
 385                       num_ours, (num_ours == 1) ? "" : "s");
 386        else if (!num_ours)
 387                printf("Your branch is behind the tracked%s branch '%s' "
 388                       "by %d commit%s,\n"
 389                       "and can be fast-forwarded.\n",
 390                       remote_msg, base,
 391                       num_theirs, (num_theirs == 1) ? "" : "s");
 392        else
 393                printf("Your branch and the tracked%s branch '%s' "
 394                       "have diverged,\nand respectively "
 395                       "have %d and %d different commit(s) each.\n",
 396                       remote_msg, base,
 397                       num_ours, num_theirs);
 398}
 399
 400static void update_refs_for_switch(struct checkout_opts *opts,
 401                                   struct branch_info *old,
 402                                   struct branch_info *new)
 403{
 404        struct strbuf msg;
 405        const char *old_desc;
 406        if (opts->new_branch) {
 407                create_branch(old->name, opts->new_branch, new->name, 0,
 408                              opts->new_branch_log, opts->track);
 409                new->name = opts->new_branch;
 410                setup_branch_path(new);
 411        }
 412
 413        strbuf_init(&msg, 0);
 414        old_desc = old->name;
 415        if (!old_desc)
 416                old_desc = sha1_to_hex(old->commit->object.sha1);
 417        strbuf_addf(&msg, "checkout: moving from %s to %s",
 418                    old_desc, new->name);
 419
 420        if (new->path) {
 421                create_symref("HEAD", new->path, msg.buf);
 422                if (!opts->quiet) {
 423                        if (old->path && !strcmp(new->path, old->path))
 424                                fprintf(stderr, "Already on \"%s\"\n",
 425                                        new->name);
 426                        else
 427                                fprintf(stderr, "Switched to%s branch \"%s\"\n",
 428                                        opts->new_branch ? " a new" : "",
 429                                        new->name);
 430                }
 431        } else if (strcmp(new->name, "HEAD")) {
 432                update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
 433                           REF_NODEREF, DIE_ON_ERR);
 434                if (!opts->quiet) {
 435                        if (old->path)
 436                                fprintf(stderr, "Note: moving to \"%s\" which isn't a local branch\nIf you want to create a new branch from this checkout, you may do so\n(now or later) by using -b with the checkout command again. Example:\n  git checkout -b <new_branch_name>\n", new->name);
 437                        describe_detached_head("HEAD is now at", new->commit);
 438                }
 439        }
 440        remove_branch_state();
 441        strbuf_release(&msg);
 442        if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
 443                report_tracking(new, opts);
 444}
 445
 446static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 447{
 448        int ret = 0;
 449        struct branch_info old;
 450        unsigned char rev[20];
 451        int flag;
 452        memset(&old, 0, sizeof(old));
 453        old.path = resolve_ref("HEAD", rev, 0, &flag);
 454        old.commit = lookup_commit_reference_gently(rev, 1);
 455        if (!(flag & REF_ISSYMREF))
 456                old.path = NULL;
 457
 458        if (old.path && !prefixcmp(old.path, "refs/heads/"))
 459                old.name = old.path + strlen("refs/heads/");
 460
 461        if (!new->name) {
 462                new->name = "HEAD";
 463                new->commit = old.commit;
 464                if (!new->commit)
 465                        die("You are on a branch yet to be born");
 466                parse_commit(new->commit);
 467        }
 468
 469        /*
 470         * If the new thing isn't a branch and isn't HEAD and we're
 471         * not starting a new branch, and we want messages, and we
 472         * weren't on a branch, and we're moving to a new commit,
 473         * describe the old commit.
 474         */
 475        if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
 476            !opts->quiet && !old.path && new->commit != old.commit)
 477                describe_detached_head("Previous HEAD position was", old.commit);
 478
 479        if (!old.commit) {
 480                if (!opts->quiet) {
 481                        fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
 482                        fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
 483                }
 484                opts->force = 1;
 485        }
 486
 487        ret = merge_working_tree(opts, &old, new);
 488        if (ret)
 489                return ret;
 490
 491        update_refs_for_switch(opts, &old, new);
 492
 493        return post_checkout_hook(old.commit, new->commit, 1);
 494}
 495
 496int cmd_checkout(int argc, const char **argv, const char *prefix)
 497{
 498        struct checkout_opts opts;
 499        unsigned char rev[20];
 500        const char *arg;
 501        struct branch_info new;
 502        struct tree *source_tree = NULL;
 503        struct option options[] = {
 504                OPT__QUIET(&opts.quiet),
 505                OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
 506                OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
 507                OPT_SET_INT('t', "track",  &opts.track, "track",
 508                        BRANCH_TRACK_EXPLICIT),
 509                OPT_BOOLEAN('f', NULL, &opts.force, "force"),
 510                OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
 511                OPT_END(),
 512        };
 513
 514        memset(&opts, 0, sizeof(opts));
 515        memset(&new, 0, sizeof(new));
 516
 517        git_config(git_default_config);
 518
 519        opts.track = git_branch_track;
 520
 521        argc = parse_options(argc, argv, options, checkout_usage, 0);
 522        if (argc) {
 523                arg = argv[0];
 524                if (get_sha1(arg, rev))
 525                        ;
 526                else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
 527                        new.name = arg;
 528                        setup_branch_path(&new);
 529                        if (resolve_ref(new.path, rev, 1, NULL))
 530                                new.commit = lookup_commit_reference(rev);
 531                        else
 532                                new.path = NULL;
 533                        parse_commit(new.commit);
 534                        source_tree = new.commit->tree;
 535                        argv++;
 536                        argc--;
 537                } else if ((source_tree = parse_tree_indirect(rev))) {
 538                        argv++;
 539                        argc--;
 540                }
 541        }
 542
 543        if (argc && !strcmp(argv[0], "--")) {
 544                argv++;
 545                argc--;
 546        }
 547
 548        if (!opts.new_branch && (opts.track != git_branch_track))
 549                die("git checkout: --track and --no-track require -b");
 550
 551        if (opts.force && opts.merge)
 552                die("git checkout: -f and -m are incompatible");
 553
 554        if (argc) {
 555                const char **pathspec = get_pathspec(prefix, argv);
 556
 557                if (!pathspec)
 558                        die("invalid path specification");
 559
 560                /* Checkout paths */
 561                if (opts.new_branch || opts.force || opts.merge) {
 562                        if (argc == 1) {
 563                                die("git checkout: updating paths is incompatible with switching branches/forcing\nDid you intend to checkout '%s' which can not be resolved as commit?", argv[0]);
 564                        } else {
 565                                die("git checkout: updating paths is incompatible with switching branches/forcing");
 566                        }
 567                }
 568
 569                return checkout_paths(source_tree, pathspec);
 570        }
 571
 572        if (new.name && !new.commit) {
 573                die("Cannot switch branch to a non-commit.");
 574        }
 575
 576        return switch_branches(&opts, &new);
 577}