builtin-update-index.con commit branch: fix segfault when resolving an invalid HEAD (078f838)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 */
   6#include "cache.h"
   7#include "strbuf.h"
   8#include "quote.h"
   9#include "cache-tree.h"
  10#include "tree-walk.h"
  11#include "builtin.h"
  12
  13/*
  14 * Default to not allowing changes to the list of files. The
  15 * tool doesn't actually care, but this makes it harder to add
  16 * files to the revision control by mistake by doing something
  17 * like "git-update-index *" and suddenly having all the object
  18 * files be revision controlled.
  19 */
  20static int allow_add;
  21static int allow_remove;
  22static int allow_replace;
  23static int info_only;
  24static int force_remove;
  25static int verbose;
  26static int mark_valid_only;
  27#define MARK_VALID 1
  28#define UNMARK_VALID 2
  29
  30static void report(const char *fmt, ...)
  31{
  32        va_list vp;
  33
  34        if (!verbose)
  35                return;
  36
  37        va_start(vp, fmt);
  38        vprintf(fmt, vp);
  39        putchar('\n');
  40        va_end(vp);
  41}
  42
  43static int mark_valid(const char *path)
  44{
  45        int namelen = strlen(path);
  46        int pos = cache_name_pos(path, namelen);
  47        if (0 <= pos) {
  48                switch (mark_valid_only) {
  49                case MARK_VALID:
  50                        active_cache[pos]->ce_flags |= htons(CE_VALID);
  51                        break;
  52                case UNMARK_VALID:
  53                        active_cache[pos]->ce_flags &= ~htons(CE_VALID);
  54                        break;
  55                }
  56                cache_tree_invalidate_path(active_cache_tree, path);
  57                active_cache_changed = 1;
  58                return 0;
  59        }
  60        return -1;
  61}
  62
  63static int add_file_to_cache(const char *path)
  64{
  65        int size, namelen, option, status;
  66        struct cache_entry *ce;
  67        struct stat st;
  68
  69        status = lstat(path, &st);
  70
  71        /* We probably want to do this in remove_file_from_cache() and
  72         * add_cache_entry() instead...
  73         */
  74        cache_tree_invalidate_path(active_cache_tree, path);
  75
  76        if (status < 0 || S_ISDIR(st.st_mode)) {
  77                /* When we used to have "path" and now we want to add
  78                 * "path/file", we need a way to remove "path" before
  79                 * being able to add "path/file".  However,
  80                 * "git-update-index --remove path" would not work.
  81                 * --force-remove can be used but this is more user
  82                 * friendly, especially since we can do the opposite
  83                 * case just fine without --force-remove.
  84                 */
  85                if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
  86                        if (allow_remove) {
  87                                if (remove_file_from_cache(path))
  88                                        return error("%s: cannot remove from the index",
  89                                                     path);
  90                                else
  91                                        return 0;
  92                        } else if (status < 0) {
  93                                return error("%s: does not exist and --remove not passed",
  94                                             path);
  95                        }
  96                }
  97                if (0 == status)
  98                        return error("%s: is a directory - add files inside instead",
  99                                     path);
 100                else
 101                        return error("lstat(\"%s\"): %s", path,
 102                                     strerror(errno));
 103        }
 104
 105        namelen = strlen(path);
 106        size = cache_entry_size(namelen);
 107        ce = xcalloc(1, size);
 108        memcpy(ce->name, path, namelen);
 109        ce->ce_flags = htons(namelen);
 110        fill_stat_cache_info(ce, &st);
 111
 112        if (trust_executable_bit && has_symlinks)
 113                ce->ce_mode = create_ce_mode(st.st_mode);
 114        else {
 115                /* If there is an existing entry, pick the mode bits and type
 116                 * from it, otherwise assume unexecutable regular file.
 117                 */
 118                struct cache_entry *ent;
 119                int pos = cache_name_pos(path, namelen);
 120
 121                ent = (0 <= pos) ? active_cache[pos] : NULL;
 122                ce->ce_mode = ce_mode_from_stat(ent, st.st_mode);
 123        }
 124
 125        if (index_path(ce->sha1, path, &st, !info_only))
 126                return -1;
 127        option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
 128        option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
 129        if (add_cache_entry(ce, option))
 130                return error("%s: cannot add to the index - missing --add option?",
 131                             path);
 132        return 0;
 133}
 134
 135static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 136                         const char *path, int stage)
 137{
 138        int size, len, option;
 139        struct cache_entry *ce;
 140
 141        if (!verify_path(path))
 142                return -1;
 143
 144        len = strlen(path);
 145        size = cache_entry_size(len);
 146        ce = xcalloc(1, size);
 147
 148        hashcpy(ce->sha1, sha1);
 149        memcpy(ce->name, path, len);
 150        ce->ce_flags = create_ce_flags(len, stage);
 151        ce->ce_mode = create_ce_mode(mode);
 152        if (assume_unchanged)
 153                ce->ce_flags |= htons(CE_VALID);
 154        option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
 155        option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
 156        if (add_cache_entry(ce, option))
 157                return error("%s: cannot add to the index - missing --add option?",
 158                             path);
 159        report("add '%s'", path);
 160        cache_tree_invalidate_path(active_cache_tree, path);
 161        return 0;
 162}
 163
 164static void chmod_path(int flip, const char *path)
 165{
 166        int pos;
 167        struct cache_entry *ce;
 168        unsigned int mode;
 169
 170        pos = cache_name_pos(path, strlen(path));
 171        if (pos < 0)
 172                goto fail;
 173        ce = active_cache[pos];
 174        mode = ntohl(ce->ce_mode);
 175        if (!S_ISREG(mode))
 176                goto fail;
 177        switch (flip) {
 178        case '+':
 179                ce->ce_mode |= htonl(0111); break;
 180        case '-':
 181                ce->ce_mode &= htonl(~0111); break;
 182        default:
 183                goto fail;
 184        }
 185        cache_tree_invalidate_path(active_cache_tree, path);
 186        active_cache_changed = 1;
 187        report("chmod %cx '%s'", flip, path);
 188        return;
 189 fail:
 190        die("git-update-index: cannot chmod %cx '%s'", flip, path);
 191}
 192
 193static void update_one(const char *path, const char *prefix, int prefix_length)
 194{
 195        const char *p = prefix_path(prefix, prefix_length, path);
 196        if (!verify_path(p)) {
 197                fprintf(stderr, "Ignoring path %s\n", path);
 198                goto free_return;
 199        }
 200        if (mark_valid_only) {
 201                if (mark_valid(p))
 202                        die("Unable to mark file %s", path);
 203                goto free_return;
 204        }
 205        cache_tree_invalidate_path(active_cache_tree, path);
 206
 207        if (force_remove) {
 208                if (remove_file_from_cache(p))
 209                        die("git-update-index: unable to remove %s", path);
 210                report("remove '%s'", path);
 211                goto free_return;
 212        }
 213        if (add_file_to_cache(p))
 214                die("Unable to process file %s", path);
 215        report("add '%s'", path);
 216 free_return:
 217        if (p < path || p > path + strlen(path))
 218                free((char*)p);
 219}
 220
 221static void read_index_info(int line_termination)
 222{
 223        struct strbuf buf;
 224        strbuf_init(&buf);
 225        while (1) {
 226                char *ptr, *tab;
 227                char *path_name;
 228                unsigned char sha1[20];
 229                unsigned int mode;
 230                unsigned long ul;
 231                int stage;
 232
 233                /* This reads lines formatted in one of three formats:
 234                 *
 235                 * (1) mode         SP sha1          TAB path
 236                 * The first format is what "git-apply --index-info"
 237                 * reports, and used to reconstruct a partial tree
 238                 * that is used for phony merge base tree when falling
 239                 * back on 3-way merge.
 240                 *
 241                 * (2) mode SP type SP sha1          TAB path
 242                 * The second format is to stuff git-ls-tree output
 243                 * into the index file.
 244                 *
 245                 * (3) mode         SP sha1 SP stage TAB path
 246                 * This format is to put higher order stages into the
 247                 * index file and matches git-ls-files --stage output.
 248                 */
 249                read_line(&buf, stdin, line_termination);
 250                if (buf.eof)
 251                        break;
 252
 253                errno = 0;
 254                ul = strtoul(buf.buf, &ptr, 8);
 255                if (ptr == buf.buf || *ptr != ' '
 256                    || errno || (unsigned int) ul != ul)
 257                        goto bad_line;
 258                mode = ul;
 259
 260                tab = strchr(ptr, '\t');
 261                if (!tab || tab - ptr < 41)
 262                        goto bad_line;
 263
 264                if (tab[-2] == ' ' && '0' <= tab[-1] && tab[-1] <= '3') {
 265                        stage = tab[-1] - '0';
 266                        ptr = tab + 1; /* point at the head of path */
 267                        tab = tab - 2; /* point at tail of sha1 */
 268                }
 269                else {
 270                        stage = 0;
 271                        ptr = tab + 1; /* point at the head of path */
 272                }
 273
 274                if (get_sha1_hex(tab - 40, sha1) || tab[-41] != ' ')
 275                        goto bad_line;
 276
 277                if (line_termination && ptr[0] == '"')
 278                        path_name = unquote_c_style(ptr, NULL);
 279                else
 280                        path_name = ptr;
 281
 282                if (!verify_path(path_name)) {
 283                        fprintf(stderr, "Ignoring path %s\n", path_name);
 284                        if (path_name != ptr)
 285                                free(path_name);
 286                        continue;
 287                }
 288                cache_tree_invalidate_path(active_cache_tree, path_name);
 289
 290                if (!mode) {
 291                        /* mode == 0 means there is no such path -- remove */
 292                        if (remove_file_from_cache(path_name))
 293                                die("git-update-index: unable to remove %s",
 294                                    ptr);
 295                }
 296                else {
 297                        /* mode ' ' sha1 '\t' name
 298                         * ptr[-1] points at tab,
 299                         * ptr[-41] is at the beginning of sha1
 300                         */
 301                        ptr[-42] = ptr[-1] = 0;
 302                        if (add_cacheinfo(mode, sha1, path_name, stage))
 303                                die("git-update-index: unable to update %s",
 304                                    path_name);
 305                }
 306                if (path_name != ptr)
 307                        free(path_name);
 308                continue;
 309
 310        bad_line:
 311                die("malformed index info %s", buf.buf);
 312        }
 313}
 314
 315static const char update_index_usage[] =
 316"git-update-index [-q] [--add] [--replace] [--remove] [--unmerged] [--refresh] [--really-refresh] [--cacheinfo] [--chmod=(+|-)x] [--assume-unchanged] [--info-only] [--force-remove] [--stdin] [--index-info] [--unresolve] [--again | -g] [--ignore-missing] [-z] [--verbose] [--] <file>...";
 317
 318static unsigned char head_sha1[20];
 319static unsigned char merge_head_sha1[20];
 320
 321static struct cache_entry *read_one_ent(const char *which,
 322                                        unsigned char *ent, const char *path,
 323                                        int namelen, int stage)
 324{
 325        unsigned mode;
 326        unsigned char sha1[20];
 327        int size;
 328        struct cache_entry *ce;
 329
 330        if (get_tree_entry(ent, path, sha1, &mode)) {
 331                if (which)
 332                        error("%s: not in %s branch.", path, which);
 333                return NULL;
 334        }
 335        if (mode == S_IFDIR) {
 336                if (which)
 337                        error("%s: not a blob in %s branch.", path, which);
 338                return NULL;
 339        }
 340        size = cache_entry_size(namelen);
 341        ce = xcalloc(1, size);
 342
 343        hashcpy(ce->sha1, sha1);
 344        memcpy(ce->name, path, namelen);
 345        ce->ce_flags = create_ce_flags(namelen, stage);
 346        ce->ce_mode = create_ce_mode(mode);
 347        return ce;
 348}
 349
 350static int unresolve_one(const char *path)
 351{
 352        int namelen = strlen(path);
 353        int pos;
 354        int ret = 0;
 355        struct cache_entry *ce_2 = NULL, *ce_3 = NULL;
 356
 357        /* See if there is such entry in the index. */
 358        pos = cache_name_pos(path, namelen);
 359        if (pos < 0) {
 360                /* If there isn't, either it is unmerged, or
 361                 * resolved as "removed" by mistake.  We do not
 362                 * want to do anything in the former case.
 363                 */
 364                pos = -pos-1;
 365                if (pos < active_nr) {
 366                        struct cache_entry *ce = active_cache[pos];
 367                        if (ce_namelen(ce) == namelen &&
 368                            !memcmp(ce->name, path, namelen)) {
 369                                fprintf(stderr,
 370                                        "%s: skipping still unmerged path.\n",
 371                                        path);
 372                                goto free_return;
 373                        }
 374                }
 375        }
 376
 377        /* Grab blobs from given path from HEAD and MERGE_HEAD,
 378         * stuff HEAD version in stage #2,
 379         * stuff MERGE_HEAD version in stage #3.
 380         */
 381        ce_2 = read_one_ent("our", head_sha1, path, namelen, 2);
 382        ce_3 = read_one_ent("their", merge_head_sha1, path, namelen, 3);
 383
 384        if (!ce_2 || !ce_3) {
 385                ret = -1;
 386                goto free_return;
 387        }
 388        if (!hashcmp(ce_2->sha1, ce_3->sha1) &&
 389            ce_2->ce_mode == ce_3->ce_mode) {
 390                fprintf(stderr, "%s: identical in both, skipping.\n",
 391                        path);
 392                goto free_return;
 393        }
 394
 395        cache_tree_invalidate_path(active_cache_tree, path);
 396        remove_file_from_cache(path);
 397        if (add_cache_entry(ce_2, ADD_CACHE_OK_TO_ADD)) {
 398                error("%s: cannot add our version to the index.", path);
 399                ret = -1;
 400                goto free_return;
 401        }
 402        if (!add_cache_entry(ce_3, ADD_CACHE_OK_TO_ADD))
 403                return 0;
 404        error("%s: cannot add their version to the index.", path);
 405        ret = -1;
 406 free_return:
 407        free(ce_2);
 408        free(ce_3);
 409        return ret;
 410}
 411
 412static void read_head_pointers(void)
 413{
 414        if (read_ref("HEAD", head_sha1))
 415                die("No HEAD -- no initial commit yet?\n");
 416        if (read_ref("MERGE_HEAD", merge_head_sha1)) {
 417                fprintf(stderr, "Not in the middle of a merge.\n");
 418                exit(0);
 419        }
 420}
 421
 422static int do_unresolve(int ac, const char **av,
 423                        const char *prefix, int prefix_length)
 424{
 425        int i;
 426        int err = 0;
 427
 428        /* Read HEAD and MERGE_HEAD; if MERGE_HEAD does not exist, we
 429         * are not doing a merge, so exit with success status.
 430         */
 431        read_head_pointers();
 432
 433        for (i = 1; i < ac; i++) {
 434                const char *arg = av[i];
 435                const char *p = prefix_path(prefix, prefix_length, arg);
 436                err |= unresolve_one(p);
 437                if (p < arg || p > arg + strlen(arg))
 438                        free((char*)p);
 439        }
 440        return err;
 441}
 442
 443static int do_reupdate(int ac, const char **av,
 444                       const char *prefix, int prefix_length)
 445{
 446        /* Read HEAD and run update-index on paths that are
 447         * merged and already different between index and HEAD.
 448         */
 449        int pos;
 450        int has_head = 1;
 451        const char **pathspec = get_pathspec(prefix, av + 1);
 452
 453        if (read_ref("HEAD", head_sha1))
 454                /* If there is no HEAD, that means it is an initial
 455                 * commit.  Update everything in the index.
 456                 */
 457                has_head = 0;
 458 redo:
 459        for (pos = 0; pos < active_nr; pos++) {
 460                struct cache_entry *ce = active_cache[pos];
 461                struct cache_entry *old = NULL;
 462                int save_nr;
 463
 464                if (ce_stage(ce) || !ce_path_match(ce, pathspec))
 465                        continue;
 466                if (has_head)
 467                        old = read_one_ent(NULL, head_sha1,
 468                                           ce->name, ce_namelen(ce), 0);
 469                if (old && ce->ce_mode == old->ce_mode &&
 470                    !hashcmp(ce->sha1, old->sha1)) {
 471                        free(old);
 472                        continue; /* unchanged */
 473                }
 474                /* Be careful.  The working tree may not have the
 475                 * path anymore, in which case, under 'allow_remove',
 476                 * or worse yet 'allow_replace', active_nr may decrease.
 477                 */
 478                save_nr = active_nr;
 479                update_one(ce->name + prefix_length, prefix, prefix_length);
 480                if (save_nr != active_nr)
 481                        goto redo;
 482        }
 483        return 0;
 484}
 485
 486int cmd_update_index(int argc, const char **argv, const char *prefix)
 487{
 488        int i, newfd, entries, has_errors = 0, line_termination = '\n';
 489        int allow_options = 1;
 490        int read_from_stdin = 0;
 491        int prefix_length = prefix ? strlen(prefix) : 0;
 492        char set_executable_bit = 0;
 493        unsigned int refresh_flags = 0;
 494        int lock_error = 0;
 495        struct lock_file *lock_file;
 496
 497        git_config(git_default_config);
 498
 499        /* We can't free this memory, it becomes part of a linked list parsed atexit() */
 500        lock_file = xcalloc(1, sizeof(struct lock_file));
 501
 502        newfd = hold_lock_file_for_update(lock_file, get_index_file(), 0);
 503        if (newfd < 0)
 504                lock_error = errno;
 505
 506        entries = read_cache();
 507        if (entries < 0)
 508                die("cache corrupted");
 509
 510        for (i = 1 ; i < argc; i++) {
 511                const char *path = argv[i];
 512                const char *p;
 513
 514                if (allow_options && *path == '-') {
 515                        if (!strcmp(path, "--")) {
 516                                allow_options = 0;
 517                                continue;
 518                        }
 519                        if (!strcmp(path, "-q")) {
 520                                refresh_flags |= REFRESH_QUIET;
 521                                continue;
 522                        }
 523                        if (!strcmp(path, "--add")) {
 524                                allow_add = 1;
 525                                continue;
 526                        }
 527                        if (!strcmp(path, "--replace")) {
 528                                allow_replace = 1;
 529                                continue;
 530                        }
 531                        if (!strcmp(path, "--remove")) {
 532                                allow_remove = 1;
 533                                continue;
 534                        }
 535                        if (!strcmp(path, "--unmerged")) {
 536                                refresh_flags |= REFRESH_UNMERGED;
 537                                continue;
 538                        }
 539                        if (!strcmp(path, "--refresh")) {
 540                                has_errors |= refresh_cache(refresh_flags);
 541                                continue;
 542                        }
 543                        if (!strcmp(path, "--really-refresh")) {
 544                                has_errors |= refresh_cache(REFRESH_REALLY | refresh_flags);
 545                                continue;
 546                        }
 547                        if (!strcmp(path, "--cacheinfo")) {
 548                                unsigned char sha1[20];
 549                                unsigned int mode;
 550
 551                                if (i+3 >= argc)
 552                                        die("git-update-index: --cacheinfo <mode> <sha1> <path>");
 553
 554                                if (strtoul_ui(argv[i+1], 8, &mode) ||
 555                                    get_sha1_hex(argv[i+2], sha1) ||
 556                                    add_cacheinfo(mode, sha1, argv[i+3], 0))
 557                                        die("git-update-index: --cacheinfo"
 558                                            " cannot add %s", argv[i+3]);
 559                                i += 3;
 560                                continue;
 561                        }
 562                        if (!strcmp(path, "--chmod=-x") ||
 563                            !strcmp(path, "--chmod=+x")) {
 564                                if (argc <= i+1)
 565                                        die("git-update-index: %s <path>", path);
 566                                set_executable_bit = path[8];
 567                                continue;
 568                        }
 569                        if (!strcmp(path, "--assume-unchanged")) {
 570                                mark_valid_only = MARK_VALID;
 571                                continue;
 572                        }
 573                        if (!strcmp(path, "--no-assume-unchanged")) {
 574                                mark_valid_only = UNMARK_VALID;
 575                                continue;
 576                        }
 577                        if (!strcmp(path, "--info-only")) {
 578                                info_only = 1;
 579                                continue;
 580                        }
 581                        if (!strcmp(path, "--force-remove")) {
 582                                force_remove = 1;
 583                                continue;
 584                        }
 585                        if (!strcmp(path, "-z")) {
 586                                line_termination = 0;
 587                                continue;
 588                        }
 589                        if (!strcmp(path, "--stdin")) {
 590                                if (i != argc - 1)
 591                                        die("--stdin must be at the end");
 592                                read_from_stdin = 1;
 593                                break;
 594                        }
 595                        if (!strcmp(path, "--index-info")) {
 596                                if (i != argc - 1)
 597                                        die("--index-info must be at the end");
 598                                allow_add = allow_replace = allow_remove = 1;
 599                                read_index_info(line_termination);
 600                                break;
 601                        }
 602                        if (!strcmp(path, "--unresolve")) {
 603                                has_errors = do_unresolve(argc - i, argv + i,
 604                                                          prefix, prefix_length);
 605                                if (has_errors)
 606                                        active_cache_changed = 0;
 607                                goto finish;
 608                        }
 609                        if (!strcmp(path, "--again") || !strcmp(path, "-g")) {
 610                                has_errors = do_reupdate(argc - i, argv + i,
 611                                                         prefix, prefix_length);
 612                                if (has_errors)
 613                                        active_cache_changed = 0;
 614                                goto finish;
 615                        }
 616                        if (!strcmp(path, "--ignore-missing")) {
 617                                refresh_flags |= REFRESH_IGNORE_MISSING;
 618                                continue;
 619                        }
 620                        if (!strcmp(path, "--verbose")) {
 621                                verbose = 1;
 622                                continue;
 623                        }
 624                        if (!strcmp(path, "-h") || !strcmp(path, "--help"))
 625                                usage(update_index_usage);
 626                        die("unknown option %s", path);
 627                }
 628                p = prefix_path(prefix, prefix_length, path);
 629                update_one(p, NULL, 0);
 630                if (set_executable_bit)
 631                        chmod_path(set_executable_bit, p);
 632                if (p < path || p > path + strlen(path))
 633                        free((char*)p);
 634        }
 635        if (read_from_stdin) {
 636                struct strbuf buf;
 637                strbuf_init(&buf);
 638                while (1) {
 639                        char *path_name;
 640                        const char *p;
 641                        read_line(&buf, stdin, line_termination);
 642                        if (buf.eof)
 643                                break;
 644                        if (line_termination && buf.buf[0] == '"')
 645                                path_name = unquote_c_style(buf.buf, NULL);
 646                        else
 647                                path_name = buf.buf;
 648                        p = prefix_path(prefix, prefix_length, path_name);
 649                        update_one(p, NULL, 0);
 650                        if (set_executable_bit)
 651                                chmod_path(set_executable_bit, p);
 652                        if (p < path_name || p > path_name + strlen(path_name))
 653                                free((char*) p);
 654                        if (path_name != buf.buf)
 655                                free(path_name);
 656                }
 657        }
 658
 659 finish:
 660        if (active_cache_changed) {
 661                if (newfd < 0) {
 662                        if (refresh_flags & REFRESH_QUIET)
 663                                exit(128);
 664                        die("unable to create '%s.lock': %s",
 665                            get_index_file(), strerror(lock_error));
 666                }
 667                if (write_cache(newfd, active_cache, active_nr) ||
 668                    close(newfd) || commit_lock_file(lock_file))
 669                        die("Unable to write new index file");
 670        }
 671
 672        rollback_lock_file(lock_file);
 673
 674        return has_errors ? 1 : 0;
 675}