builtin/bisect--helper.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "parse-options.h"
   4 #include "bisect.h"
   5 #include "refs.h"
   6 #include "dir.h"
   7 #include "strvec.h"
   8 #include "run-command.h"
   9 #include "prompt.h"
  10 #include "quote.h"
  11 #include "revision.h"
  12
  13 static GIT_PATH_FUNC(git_path_bisect_terms, "BISECT_TERMS")
  14 static GIT_PATH_FUNC(git_path_bisect_expected_rev, "BISECT_EXPECTED_REV")
  15 static GIT_PATH_FUNC(git_path_bisect_ancestors_ok, "BISECT_ANCESTORS_OK")
  16 static GIT_PATH_FUNC(git_path_bisect_start, "BISECT_START")
  17 static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG")
  18 static GIT_PATH_FUNC(git_path_head_name, "head-name")
  19 static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
  20 static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT")
  21 static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN")
  22
  23 static const char * const git_bisect_helper_usage[] = {
  24         N_("git bisect--helper --bisect-reset [<commit>]"),
  25         "git bisect--helper --bisect-terms [--term-good | --term-old | --term-bad | --term-new]",
  26         N_("git bisect--helper --bisect-start [--term-{new,bad}=<term> --term-{old,good}=<term>]"
  27                                             " [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<paths>...]"),
  28         "git bisect--helper --bisect-next",
  29         N_("git bisect--helper --bisect-state (bad|new) [<rev>]"),
  30         N_("git bisect--helper --bisect-state (good|old) [<rev>...]"),
  31         N_("git bisect--helper --bisect-replay <filename>"),
  32         N_("git bisect--helper --bisect-skip [(<rev>|<range>)...]"),
  33         "git bisect--helper --bisect-visualize",
  34         N_("git bisect--helper --bisect-run <cmd>..."),
  35         NULL
  36 };
  37
  38 struct add_bisect_ref_data {
  39         struct rev_info *revs;
  40         unsigned int object_flags;
  41 };
  42
  43 struct bisect_terms {
  44         char *term_good;
  45         char *term_bad;
  46 };
  47
  48 static void free_terms(struct bisect_terms *terms)
  49 {
  50         FREE_AND_NULL(terms->term_good);
  51         FREE_AND_NULL(terms->term_bad);
  52 }
  53
  54 static void set_terms(struct bisect_terms *terms, const char *bad,
  55                       const char *good)
  56 {
  57         free((void *)terms->term_good);
  58         terms->term_good = xstrdup(good);
  59         free((void *)terms->term_bad);
  60         terms->term_bad = xstrdup(bad);
  61 }
  62
  63 static const char vocab_bad[] = "bad|new";
  64 static const char vocab_good[] = "good|old";
  65
  66 static int bisect_autostart(struct bisect_terms *terms);
  67
  68 /*
  69  * Check whether the string `term` belongs to the set of strings
  70  * included in the variable arguments.
  71  */
  72 LAST_ARG_MUST_BE_NULL
  73 static int one_of(const char *term, ...)
  74 {
  75         int res = 0;
  76         va_list matches;
  77         const char *match;
  78
  79         va_start(matches, term);
  80         while (!res && (match = va_arg(matches, const char *)))
  81                 res = !strcmp(term, match);
  82         va_end(matches);
  83
  84         return res;
  85 }
  86
  87 /*
  88  * return code BISECT_INTERNAL_SUCCESS_MERGE_BASE
  89  * and BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND are codes
  90  * that indicate special success.
  91  */
  92
  93 static int is_bisect_success(enum bisect_error res)
  94 {
  95         return !res ||
  96                 res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND ||
  97                 res == BISECT_INTERNAL_SUCCESS_MERGE_BASE;
  98 }
  99
 100 static int write_in_file(const char *path, const char *mode, const char *format, va_list args)
 101 {
 102         FILE *fp = NULL;
 103         int res = 0;
 104
 105         if (strcmp(mode, "w") && strcmp(mode, "a"))
 106                 BUG("write-in-file does not support '%s' mode", mode);
 107         fp = fopen(path, mode);
 108         if (!fp)
 109                 return error_errno(_("cannot open file '%s' in mode '%s'"), path, mode);
 110         res = vfprintf(fp, format, args);
 111
 112         if (res < 0) {
 113                 int saved_errno = errno;
 114                 fclose(fp);
 115                 errno = saved_errno;
 116                 return error_errno(_("could not write to file '%s'"), path);
 117         }
 118
 119         return fclose(fp);
 120 }
 121
 122 __attribute__((format (printf, 2, 3)))
 123 static int write_to_file(const char *path, const char *format, ...)
 124 {
 125         int res;
 126         va_list args;
 127
 128         va_start(args, format);
 129         res = write_in_file(path, "w", format, args);
 130         va_end(args);
 131
 132         return res;
 133 }
 134
 135 __attribute__((format (printf, 2, 3)))
 136 static int append_to_file(const char *path, const char *format, ...)
 137 {
 138         int res;
 139         va_list args;
 140
 141         va_start(args, format);
 142         res = write_in_file(path, "a", format, args);
 143         va_end(args);
 144
 145         return res;
 146 }
 147
 148 static int print_file_to_stdout(const char *path)
 149 {
 150         int fd = open(path, O_RDONLY);
 151         int ret = 0;
 152
 153         if (fd < 0)
 154                 return error_errno(_("cannot open file '%s' for reading"), path);
 155         if (copy_fd(fd, 1) < 0)
 156                 ret = error_errno(_("failed to read '%s'"), path);
 157         close(fd);
 158         return ret;
 159 }
 160
 161 static int check_term_format(const char *term, const char *orig_term)
 162 {
 163         int res;
 164         char *new_term = xstrfmt("refs/bisect/%s", term);
 165
 166         res = check_refname_format(new_term, 0);
 167         free(new_term);
 168
 169         if (res)
 170                 return error(_("'%s' is not a valid term"), term);
 171
 172         if (one_of(term, "help", "start", "skip", "next", "reset",
 173                         "visualize", "view", "replay", "log", "run", "terms", NULL))
 174                 return error(_("can't use the builtin command '%s' as a term"), term);
 175
 176         /*
 177          * In theory, nothing prevents swapping completely good and bad,
 178          * but this situation could be confusing and hasn't been tested
 179          * enough. Forbid it for now.
 180          */
 181
 182         if ((strcmp(orig_term, "bad") && one_of(term, "bad", "new", NULL)) ||
 183                  (strcmp(orig_term, "good") && one_of(term, "good", "old", NULL)))
 184                 return error(_("can't change the meaning of the term '%s'"), term);
 185
 186         return 0;
 187 }
 188
 189 static int write_terms(const char *bad, const char *good)
 190 {
 191         int res;
 192
 193         if (!strcmp(bad, good))
 194                 return error(_("please use two different terms"));
 195
 196         if (check_term_format(bad, "bad") || check_term_format(good, "good"))
 197                 return -1;
 198
 199         res = write_to_file(git_path_bisect_terms(), "%s\n%s\n", bad, good);
 200
 201         return res;
 202 }
 203
 204 static int bisect_reset(const char *commit)
 205 {
 206         struct strbuf branch = STRBUF_INIT;
 207
 208         if (!commit) {
 209                 if (strbuf_read_file(&branch, git_path_bisect_start(), 0) < 1) {
 210                         printf(_("We are not bisecting.\n"));
 211                         return 0;
 212                 }
 213                 strbuf_rtrim(&branch);
 214         } else {
 215                 struct object_id oid;
 216
 217                 if (get_oid_commit(commit, &oid))
 218                         return error(_("'%s' is not a valid commit"), commit);
 219                 strbuf_addstr(&branch, commit);
 220         }
 221
 222         if (!ref_exists("BISECT_HEAD")) {
 223                 struct strvec argv = STRVEC_INIT;
 224
 225                 strvec_pushl(&argv, "checkout", branch.buf, "--", NULL);
 226                 if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 227                         error(_("could not check out original"
 228                                 " HEAD '%s'. Try 'git bisect"
 229                                 " reset <commit>'."), branch.buf);
 230                         strbuf_release(&branch);
 231                         strvec_clear(&argv);
 232                         return -1;
 233                 }
 234                 strvec_clear(&argv);
 235         }
 236
 237         strbuf_release(&branch);
 238         return bisect_clean_state();
 239 }
 240
 241 static void log_commit(FILE *fp, char *fmt, const char *state,
 242                        struct commit *commit)
 243 {
 244         struct pretty_print_context pp = {0};
 245         struct strbuf commit_msg = STRBUF_INIT;
 246         char *label = xstrfmt(fmt, state);
 247
 248         format_commit_message(commit, "%s", &commit_msg, &pp);
 249
 250         fprintf(fp, "# %s: [%s] %s\n", label, oid_to_hex(&commit->object.oid),
 251                 commit_msg.buf);
 252
 253         strbuf_release(&commit_msg);
 254         free(label);
 255 }
 256
 257 static int bisect_write(const char *state, const char *rev,
 258                         const struct bisect_terms *terms, int nolog)
 259 {
 260         struct strbuf tag = STRBUF_INIT;
 261         struct object_id oid;
 262         struct commit *commit;
 263         FILE *fp = NULL;
 264         int res = 0;
 265
 266         if (!strcmp(state, terms->term_bad)) {
 267                 strbuf_addf(&tag, "refs/bisect/%s", state);
 268         } else if (one_of(state, terms->term_good, "skip", NULL)) {
 269                 strbuf_addf(&tag, "refs/bisect/%s-%s", state, rev);
 270         } else {
 271                 res = error(_("Bad bisect_write argument: %s"), state);
 272                 goto finish;
 273         }
 274
 275         if (get_oid(rev, &oid)) {
 276                 res = error(_("couldn't get the oid of the rev '%s'"), rev);
 277                 goto finish;
 278         }
 279
 280         if (update_ref(NULL, tag.buf, &oid, NULL, 0,
 281                        UPDATE_REFS_MSG_ON_ERR)) {
 282                 res = -1;
 283                 goto finish;
 284         }
 285
 286         fp = fopen(git_path_bisect_log(), "a");
 287         if (!fp) {
 288                 res = error_errno(_("couldn't open the file '%s'"), git_path_bisect_log());
 289                 goto finish;
 290         }
 291
 292         commit = lookup_commit_reference(the_repository, &oid);
 293         log_commit(fp, "%s", state, commit);
 294
 295         if (!nolog)
 296                 fprintf(fp, "git bisect %s %s\n", state, rev);
 297
 298 finish:
 299         if (fp)
 300                 fclose(fp);
 301         strbuf_release(&tag);
 302         return res;
 303 }
 304
 305 static int check_and_set_terms(struct bisect_terms *terms, const char *cmd)
 306 {
 307         int has_term_file = !is_empty_or_missing_file(git_path_bisect_terms());
 308
 309         if (one_of(cmd, "skip", "start", "terms", NULL))
 310                 return 0;
 311
 312         if (has_term_file && strcmp(cmd, terms->term_bad) &&
 313             strcmp(cmd, terms->term_good))
 314                 return error(_("Invalid command: you're currently in a "
 315                                 "%s/%s bisect"), terms->term_bad,
 316                                 terms->term_good);
 317
 318         if (!has_term_file) {
 319                 if (one_of(cmd, "bad", "good", NULL)) {
 320                         set_terms(terms, "bad", "good");
 321                         return write_terms(terms->term_bad, terms->term_good);
 322                 }
 323                 if (one_of(cmd, "new", "old", NULL)) {
 324                         set_terms(terms, "new", "old");
 325                         return write_terms(terms->term_bad, terms->term_good);
 326                 }
 327         }
 328
 329         return 0;
 330 }
 331
 332 static int inc_nr(const char *refname, const struct object_id *oid,
 333                   int flag, void *cb_data)
 334 {
 335         unsigned int *nr = (unsigned int *)cb_data;
 336         (*nr)++;
 337         return 0;
 338 }
 339
 340 static const char need_bad_and_good_revision_warning[] =
 341         N_("You need to give me at least one %s and %s revision.\n"
 342            "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 343
 344 static const char need_bisect_start_warning[] =
 345         N_("You need to start by \"git bisect start\".\n"
 346            "You then need to give me at least one %s and %s revision.\n"
 347            "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 348
 349 static int decide_next(const struct bisect_terms *terms,
 350                        const char *current_term, int missing_good,
 351                        int missing_bad)
 352 {
 353         if (!missing_good && !missing_bad)
 354                 return 0;
 355         if (!current_term)
 356                 return -1;
 357
 358         if (missing_good && !missing_bad &&
 359             !strcmp(current_term, terms->term_good)) {
 360                 char *yesno;
 361                 /*
 362                  * have bad (or new) but not good (or old). We could bisect
 363                  * although this is less optimum.
 364                  */
 365                 warning(_("bisecting only with a %s commit"), terms->term_bad);
 366                 if (!isatty(0))
 367                         return 0;
 368                 /*
 369                  * TRANSLATORS: Make sure to include [Y] and [n] in your
 370                  * translation. The program will only accept English input
 371                  * at this point.
 372                  */
 373                 yesno = git_prompt(_("Are you sure [Y/n]? "), PROMPT_ECHO);
 374                 if (starts_with(yesno, "N") || starts_with(yesno, "n"))
 375                         return -1;
 376                 return 0;
 377         }
 378
 379         if (!is_empty_or_missing_file(git_path_bisect_start()))
 380                 return error(_(need_bad_and_good_revision_warning),
 381                              vocab_bad, vocab_good, vocab_bad, vocab_good);
 382         else
 383                 return error(_(need_bisect_start_warning),
 384                              vocab_good, vocab_bad, vocab_good, vocab_bad);
 385 }
 386
 387 static void bisect_status(struct bisect_state *state,
 388                           const struct bisect_terms *terms)
 389 {
 390         char *bad_ref = xstrfmt("refs/bisect/%s", terms->term_bad);
 391         char *good_glob = xstrfmt("%s-*", terms->term_good);
 392
 393         if (ref_exists(bad_ref))
 394                 state->nr_bad = 1;
 395
 396         for_each_glob_ref_in(inc_nr, good_glob, "refs/bisect/",
 397                              (void *) &state->nr_good);
 398
 399         free(good_glob);
 400         free(bad_ref);
 401 }
 402
 403 __attribute__((format (printf, 1, 2)))
 404 static void bisect_log_printf(const char *fmt, ...)
 405 {
 406         struct strbuf buf = STRBUF_INIT;
 407         va_list ap;
 408
 409         va_start(ap, fmt);
 410         strbuf_vaddf(&buf, fmt, ap);
 411         va_end(ap);
 412
 413         printf("%s", buf.buf);
 414         append_to_file(git_path_bisect_log(), "# %s", buf.buf);
 415
 416         strbuf_release(&buf);
 417 }
 418
 419 static void bisect_print_status(const struct bisect_terms *terms)
 420 {
 421         struct bisect_state state = { 0 };
 422
 423         bisect_status(&state, terms);
 424
 425         /* If we had both, we'd already be started, and shouldn't get here. */
 426         if (state.nr_good && state.nr_bad)
 427                 return;
 428
 429         if (!state.nr_good && !state.nr_bad)
 430                 bisect_log_printf(_("status: waiting for both good and bad commits\n"));
 431         else if (state.nr_good)
 432                 bisect_log_printf(Q_("status: waiting for bad commit, %d good commit known\n",
 433                                      "status: waiting for bad commit, %d good commits known\n",
 434                                      state.nr_good), state.nr_good);
 435         else
 436                 bisect_log_printf(_("status: waiting for good commit(s), bad commit known\n"));
 437 }
 438
 439 static int bisect_next_check(const struct bisect_terms *terms,
 440                              const char *current_term)
 441 {
 442         struct bisect_state state = { 0 };
 443         bisect_status(&state, terms);
 444         return decide_next(terms, current_term, !state.nr_good, !state.nr_bad);
 445 }
 446
 447 static int get_terms(struct bisect_terms *terms)
 448 {
 449         struct strbuf str = STRBUF_INIT;
 450         FILE *fp = NULL;
 451         int res = 0;
 452
 453         fp = fopen(git_path_bisect_terms(), "r");
 454         if (!fp) {
 455                 res = -1;
 456                 goto finish;
 457         }
 458
 459         free_terms(terms);
 460         strbuf_getline_lf(&str, fp);
 461         terms->term_bad = strbuf_detach(&str, NULL);
 462         strbuf_getline_lf(&str, fp);
 463         terms->term_good = strbuf_detach(&str, NULL);
 464
 465 finish:
 466         if (fp)
 467                 fclose(fp);
 468         strbuf_release(&str);
 469         return res;
 470 }
 471
 472 static int bisect_terms(struct bisect_terms *terms, const char *option)
 473 {
 474         if (get_terms(terms))
 475                 return error(_("no terms defined"));
 476
 477         if (!option) {
 478                 printf(_("Your current terms are %s for the old state\n"
 479                          "and %s for the new state.\n"),
 480                        terms->term_good, terms->term_bad);
 481                 return 0;
 482         }
 483         if (one_of(option, "--term-good", "--term-old", NULL))
 484                 printf("%s\n", terms->term_good);
 485         else if (one_of(option, "--term-bad", "--term-new", NULL))
 486                 printf("%s\n", terms->term_bad);
 487         else
 488                 return error(_("invalid argument %s for 'git bisect terms'.\n"
 489                                "Supported options are: "
 490                                "--term-good|--term-old and "
 491                                "--term-bad|--term-new."), option);
 492
 493         return 0;
 494 }
 495
 496 static int bisect_append_log_quoted(const char **argv)
 497 {
 498         int res = 0;
 499         FILE *fp = fopen(git_path_bisect_log(), "a");
 500         struct strbuf orig_args = STRBUF_INIT;
 501
 502         if (!fp)
 503                 return -1;
 504
 505         if (fprintf(fp, "git bisect start") < 1) {
 506                 res = -1;
 507                 goto finish;
 508         }
 509
 510         sq_quote_argv(&orig_args, argv);
 511         if (fprintf(fp, "%s\n", orig_args.buf) < 1)
 512                 res = -1;
 513
 514 finish:
 515         fclose(fp);
 516         strbuf_release(&orig_args);
 517         return res;
 518 }
 519
 520 static int add_bisect_ref(const char *refname, const struct object_id *oid,
 521                           int flags, void *cb)
 522 {
 523         struct add_bisect_ref_data *data = cb;
 524
 525         add_pending_oid(data->revs, refname, oid, data->object_flags);
 526
 527         return 0;
 528 }
 529
 530 static int prepare_revs(struct bisect_terms *terms, struct rev_info *revs)
 531 {
 532         int res = 0;
 533         struct add_bisect_ref_data cb = { revs };
 534         char *good = xstrfmt("%s-*", terms->term_good);
 535
 536         /*
 537          * We cannot use terms->term_bad directly in
 538          * for_each_glob_ref_in() and we have to append a '*' to it,
 539          * otherwise for_each_glob_ref_in() will append '/' and '*'.
 540          */
 541         char *bad = xstrfmt("%s*", terms->term_bad);
 542
 543         /*
 544          * It is important to reset the flags used by revision walks
 545          * as the previous call to bisect_next_all() in turn
 546          * sets up a revision walk.
 547          */
 548         reset_revision_walk();
 549         init_revisions(revs, NULL);
 550         setup_revisions(0, NULL, revs, NULL);
 551         for_each_glob_ref_in(add_bisect_ref, bad, "refs/bisect/", &cb);
 552         cb.object_flags = UNINTERESTING;
 553         for_each_glob_ref_in(add_bisect_ref, good, "refs/bisect/", &cb);
 554         if (prepare_revision_walk(revs))
 555                 res = error(_("revision walk setup failed\n"));
 556
 557         free(good);
 558         free(bad);
 559         return res;
 560 }
 561
 562 static int bisect_skipped_commits(struct bisect_terms *terms)
 563 {
 564         int res;
 565         FILE *fp = NULL;
 566         struct rev_info revs;
 567         struct commit *commit;
 568         struct pretty_print_context pp = {0};
 569         struct strbuf commit_name = STRBUF_INIT;
 570
 571         res = prepare_revs(terms, &revs);
 572         if (res)
 573                 return res;
 574
 575         fp = fopen(git_path_bisect_log(), "a");
 576         if (!fp)
 577                 return error_errno(_("could not open '%s' for appending"),
 578                                   git_path_bisect_log());
 579
 580         if (fprintf(fp, "# only skipped commits left to test\n") < 0)
 581                 return error_errno(_("failed to write to '%s'"), git_path_bisect_log());
 582
 583         while ((commit = get_revision(&revs)) != NULL) {
 584                 strbuf_reset(&commit_name);
 585                 format_commit_message(commit, "%s",
 586                                       &commit_name, &pp);
 587                 fprintf(fp, "# possible first %s commit: [%s] %s\n",
 588                         terms->term_bad, oid_to_hex(&commit->object.oid),
 589                         commit_name.buf);
 590         }
 591
 592         /*
 593          * Reset the flags used by revision walks in case
 594          * there is another revision walk after this one.
 595          */
 596         reset_revision_walk();
 597
 598         strbuf_release(&commit_name);
 599         release_revisions(&revs);
 600         fclose(fp);
 601         return 0;
 602 }
 603
 604 static int bisect_successful(struct bisect_terms *terms)
 605 {
 606         struct object_id oid;
 607         struct commit *commit;
 608         struct pretty_print_context pp = {0};
 609         struct strbuf commit_name = STRBUF_INIT;
 610         char *bad_ref = xstrfmt("refs/bisect/%s",terms->term_bad);
 611         int res;
 612
 613         read_ref(bad_ref, &oid);
 614         commit = lookup_commit_reference_by_name(bad_ref);
 615         format_commit_message(commit, "%s", &commit_name, &pp);
 616
 617         res = append_to_file(git_path_bisect_log(), "# first %s commit: [%s] %s\n",
 618                             terms->term_bad, oid_to_hex(&commit->object.oid),
 619                             commit_name.buf);
 620
 621         strbuf_release(&commit_name);
 622         free(bad_ref);
 623         return res;
 624 }
 625
 626 static enum bisect_error bisect_next(struct bisect_terms *terms, const char *prefix)
 627 {
 628         enum bisect_error res;
 629
 630         if (bisect_autostart(terms))
 631                 return BISECT_FAILED;
 632
 633         if (bisect_next_check(terms, terms->term_good))
 634                 return BISECT_FAILED;
 635
 636         /* Perform all bisection computation */
 637         res = bisect_next_all(the_repository, prefix);
 638
 639         if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
 640                 res = bisect_successful(terms);
 641                 return res ? res : BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND;
 642         } else if (res == BISECT_ONLY_SKIPPED_LEFT) {
 643                 res = bisect_skipped_commits(terms);
 644                 return res ? res : BISECT_ONLY_SKIPPED_LEFT;
 645         }
 646         return res;
 647 }
 648
 649 static enum bisect_error bisect_auto_next(struct bisect_terms *terms, const char *prefix)
 650 {
 651         if (bisect_next_check(terms, NULL)) {
 652                 bisect_print_status(terms);
 653                 return BISECT_OK;
 654         }
 655
 656         return bisect_next(terms, prefix);
 657 }
 658
 659 static enum bisect_error bisect_start(struct bisect_terms *terms, const char **argv, int argc)
 660 {
 661         int no_checkout = 0;
 662         int first_parent_only = 0;
 663         int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
 664         int flags, pathspec_pos;
 665         enum bisect_error res = BISECT_OK;
 666         struct string_list revs = STRING_LIST_INIT_DUP;
 667         struct string_list states = STRING_LIST_INIT_DUP;
 668         struct strbuf start_head = STRBUF_INIT;
 669         struct strbuf bisect_names = STRBUF_INIT;
 670         struct object_id head_oid;
 671         struct object_id oid;
 672         const char *head;
 673
 674         if (is_bare_repository())
 675                 no_checkout = 1;
 676
 677         /*
 678          * Check for one bad and then some good revisions
 679          */
 680         for (i = 0; i < argc; i++) {
 681                 if (!strcmp(argv[i], "--")) {
 682                         has_double_dash = 1;
 683                         break;
 684                 }
 685         }
 686
 687         for (i = 0; i < argc; i++) {
 688                 const char *arg = argv[i];
 689                 if (!strcmp(argv[i], "--")) {
 690                         break;
 691                 } else if (!strcmp(arg, "--no-checkout")) {
 692                         no_checkout = 1;
 693                 } else if (!strcmp(arg, "--first-parent")) {
 694                         first_parent_only = 1;
 695                 } else if (!strcmp(arg, "--term-good") ||
 696                          !strcmp(arg, "--term-old")) {
 697                         i++;
 698                         if (argc <= i)
 699                                 return error(_("'' is not a valid term"));
 700                         must_write_terms = 1;
 701                         free((void *) terms->term_good);
 702                         terms->term_good = xstrdup(argv[i]);
 703                 } else if (skip_prefix(arg, "--term-good=", &arg) ||
 704                            skip_prefix(arg, "--term-old=", &arg)) {
 705                         must_write_terms = 1;
 706                         free((void *) terms->term_good);
 707                         terms->term_good = xstrdup(arg);
 708                 } else if (!strcmp(arg, "--term-bad") ||
 709                          !strcmp(arg, "--term-new")) {
 710                         i++;
 711                         if (argc <= i)
 712                                 return error(_("'' is not a valid term"));
 713                         must_write_terms = 1;
 714                         free((void *) terms->term_bad);
 715                         terms->term_bad = xstrdup(argv[i]);
 716                 } else if (skip_prefix(arg, "--term-bad=", &arg) ||
 717                            skip_prefix(arg, "--term-new=", &arg)) {
 718                         must_write_terms = 1;
 719                         free((void *) terms->term_bad);
 720                         terms->term_bad = xstrdup(arg);
 721                 } else if (starts_with(arg, "--")) {
 722                         return error(_("unrecognized option: '%s'"), arg);
 723                 } else if (!get_oidf(&oid, "%s^{commit}", arg)) {
 724                         string_list_append(&revs, oid_to_hex(&oid));
 725                 } else if (has_double_dash) {
 726                         die(_("'%s' does not appear to be a valid "
 727                               "revision"), arg);
 728                 } else {
 729                         break;
 730                 }
 731         }
 732         pathspec_pos = i;
 733
 734         /*
 735          * The user ran "git bisect start <sha1> <sha1>", hence did not
 736          * explicitly specify the terms, but we are already starting to
 737          * set references named with the default terms, and won't be able
 738          * to change afterwards.
 739          */
 740         if (revs.nr)
 741                 must_write_terms = 1;
 742         for (i = 0; i < revs.nr; i++) {
 743                 if (bad_seen) {
 744                         string_list_append(&states, terms->term_good);
 745                 } else {
 746                         bad_seen = 1;
 747                         string_list_append(&states, terms->term_bad);
 748                 }
 749         }
 750
 751         /*
 752          * Verify HEAD
 753          */
 754         head = resolve_ref_unsafe("HEAD", 0, &head_oid, &flags);
 755         if (!head)
 756                 if (get_oid("HEAD", &head_oid))
 757                         return error(_("bad HEAD - I need a HEAD"));
 758
 759         /*
 760          * Check if we are bisecting
 761          */
 762         if (!is_empty_or_missing_file(git_path_bisect_start())) {
 763                 /* Reset to the rev from where we started */
 764                 strbuf_read_file(&start_head, git_path_bisect_start(), 0);
 765                 strbuf_trim(&start_head);
 766                 if (!no_checkout) {
 767                         struct strvec argv = STRVEC_INIT;
 768
 769                         strvec_pushl(&argv, "checkout", start_head.buf,
 770                                      "--", NULL);
 771                         if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 772                                 res = error(_("checking out '%s' failed."
 773                                                  " Try 'git bisect start "
 774                                                  "<valid-branch>'."),
 775                                                start_head.buf);
 776                                 goto finish;
 777                         }
 778                 }
 779         } else {
 780                 /* Get the rev from where we start. */
 781                 if (!get_oid(head, &head_oid) &&
 782                     !starts_with(head, "refs/heads/")) {
 783                         strbuf_reset(&start_head);
 784                         strbuf_addstr(&start_head, oid_to_hex(&head_oid));
 785                 } else if (!get_oid(head, &head_oid) &&
 786                            skip_prefix(head, "refs/heads/", &head)) {
 787                         /*
 788                          * This error message should only be triggered by
 789                          * cogito usage, and cogito users should understand
 790                          * it relates to cg-seek.
 791                          */
 792                         if (!is_empty_or_missing_file(git_path_head_name()))
 793                                 return error(_("won't bisect on cg-seek'ed tree"));
 794                         strbuf_addstr(&start_head, head);
 795                 } else {
 796                         return error(_("bad HEAD - strange symbolic ref"));
 797                 }
 798         }
 799
 800         /*
 801          * Get rid of any old bisect state.
 802          */
 803         if (bisect_clean_state())
 804                 return BISECT_FAILED;
 805
 806         /*
 807          * Write new start state
 808          */
 809         write_file(git_path_bisect_start(), "%s\n", start_head.buf);
 810
 811         if (first_parent_only)
 812                 write_file(git_path_bisect_first_parent(), "\n");
 813
 814         if (no_checkout) {
 815                 if (get_oid(start_head.buf, &oid) < 0) {
 816                         res = error(_("invalid ref: '%s'"), start_head.buf);
 817                         goto finish;
 818                 }
 819                 if (update_ref(NULL, "BISECT_HEAD", &oid, NULL, 0,
 820                                UPDATE_REFS_MSG_ON_ERR)) {
 821                         res = BISECT_FAILED;
 822                         goto finish;
 823                 }
 824         }
 825
 826         if (pathspec_pos < argc - 1)
 827                 sq_quote_argv(&bisect_names, argv + pathspec_pos);
 828         write_file(git_path_bisect_names(), "%s\n", bisect_names.buf);
 829
 830         for (i = 0; i < states.nr; i++)
 831                 if (bisect_write(states.items[i].string,
 832                                  revs.items[i].string, terms, 1)) {
 833                         res = BISECT_FAILED;
 834                         goto finish;
 835                 }
 836
 837         if (must_write_terms && write_terms(terms->term_bad,
 838                                             terms->term_good)) {
 839                 res = BISECT_FAILED;
 840                 goto finish;
 841         }
 842
 843         res = bisect_append_log_quoted(argv);
 844         if (res)
 845                 res = BISECT_FAILED;
 846
 847 finish:
 848         string_list_clear(&revs, 0);
 849         string_list_clear(&states, 0);
 850         strbuf_release(&start_head);
 851         strbuf_release(&bisect_names);
 852         if (res)
 853                 return res;
 854
 855         res = bisect_auto_next(terms, NULL);
 856         if (!is_bisect_success(res))
 857                 bisect_clean_state();
 858         return res;
 859 }
 860
 861 static inline int file_is_not_empty(const char *path)
 862 {
 863         return !is_empty_or_missing_file(path);
 864 }
 865
 866 static int bisect_autostart(struct bisect_terms *terms)
 867 {
 868         int res;
 869         const char *yesno;
 870
 871         if (file_is_not_empty(git_path_bisect_start()))
 872                 return 0;
 873
 874         fprintf_ln(stderr, _("You need to start by \"git bisect "
 875                           "start\"\n"));
 876
 877         if (!isatty(STDIN_FILENO))
 878                 return -1;
 879
 880         /*
 881          * TRANSLATORS: Make sure to include [Y] and [n] in your
 882          * translation. The program will only accept English input
 883          * at this point.
 884          */
 885         yesno = git_prompt(_("Do you want me to do it for you "
 886                              "[Y/n]? "), PROMPT_ECHO);
 887         res = tolower(*yesno) == 'n' ?
 888                 -1 : bisect_start(terms, empty_strvec, 0);
 889
 890         return res;
 891 }
 892
 893 static enum bisect_error bisect_state(struct bisect_terms *terms, const char **argv,
 894                                       int argc)
 895 {
 896         const char *state;
 897         int i, verify_expected = 1;
 898         struct object_id oid, expected;
 899         struct strbuf buf = STRBUF_INIT;
 900         struct oid_array revs = OID_ARRAY_INIT;
 901
 902         if (!argc)
 903                 return error(_("Please call `--bisect-state` with at least one argument"));
 904
 905         if (bisect_autostart(terms))
 906                 return BISECT_FAILED;
 907
 908         state = argv[0];
 909         if (check_and_set_terms(terms, state) ||
 910             !one_of(state, terms->term_good, terms->term_bad, "skip", NULL))
 911                 return BISECT_FAILED;
 912
 913         argv++;
 914         argc--;
 915         if (argc > 1 && !strcmp(state, terms->term_bad))
 916                 return error(_("'git bisect %s' can take only one argument."), terms->term_bad);
 917
 918         if (argc == 0) {
 919                 const char *head = "BISECT_HEAD";
 920                 enum get_oid_result res_head = get_oid(head, &oid);
 921
 922                 if (res_head == MISSING_OBJECT) {
 923                         head = "HEAD";
 924                         res_head = get_oid(head, &oid);
 925                 }
 926
 927                 if (res_head)
 928                         error(_("Bad rev input: %s"), head);
 929                 oid_array_append(&revs, &oid);
 930         }
 931
 932         /*
 933          * All input revs must be checked before executing bisect_write()
 934          * to discard junk revs.
 935          */
 936
 937         for (; argc; argc--, argv++) {
 938                 struct commit *commit;
 939
 940                 if (get_oid(*argv, &oid)){
 941                         error(_("Bad rev input: %s"), *argv);
 942                         oid_array_clear(&revs);
 943                         return BISECT_FAILED;
 944                 }
 945
 946                 commit = lookup_commit_reference(the_repository, &oid);
 947                 if (!commit)
 948                         die(_("Bad rev input (not a commit): %s"), *argv);
 949
 950                 oid_array_append(&revs, &commit->object.oid);
 951         }
 952
 953         if (strbuf_read_file(&buf, git_path_bisect_expected_rev(), 0) < the_hash_algo->hexsz ||
 954             get_oid_hex(buf.buf, &expected) < 0)
 955                 verify_expected = 0; /* Ignore invalid file contents */
 956         strbuf_release(&buf);
 957
 958         for (i = 0; i < revs.nr; i++) {
 959                 if (bisect_write(state, oid_to_hex(&revs.oid[i]), terms, 0)) {
 960                         oid_array_clear(&revs);
 961                         return BISECT_FAILED;
 962                 }
 963                 if (verify_expected && !oideq(&revs.oid[i], &expected)) {
 964                         unlink_or_warn(git_path_bisect_ancestors_ok());
 965                         unlink_or_warn(git_path_bisect_expected_rev());
 966                         verify_expected = 0;
 967                 }
 968         }
 969
 970         oid_array_clear(&revs);
 971         return bisect_auto_next(terms, NULL);
 972 }
 973
 974 static enum bisect_error bisect_log(void)
 975 {
 976         int fd, status;
 977         const char* filename = git_path_bisect_log();
 978
 979         if (is_empty_or_missing_file(filename))
 980                 return error(_("We are not bisecting."));
 981
 982         fd = open(filename, O_RDONLY);
 983         if (fd < 0)
 984                 return BISECT_FAILED;
 985
 986         status = copy_fd(fd, STDOUT_FILENO);
 987         close(fd);
 988         return status ? BISECT_FAILED : BISECT_OK;
 989 }
 990
 991 static int process_replay_line(struct bisect_terms *terms, struct strbuf *line)
 992 {
 993         const char *p = line->buf + strspn(line->buf, " \t");
 994         char *word_end, *rev;
 995
 996         if ((!skip_prefix(p, "git bisect", &p) &&
 997         !skip_prefix(p, "git-bisect", &p)) || !isspace(*p))
 998                 return 0;
 999         p += strspn(p, " \t");
1000
1001         word_end = (char *)p + strcspn(p, " \t");
1002         rev = word_end + strspn(word_end, " \t");
1003         *word_end = '\0'; /* NUL-terminate the word */
1004
1005         get_terms(terms);
1006         if (check_and_set_terms(terms, p))
1007                 return -1;
1008
1009         if (!strcmp(p, "start")) {
1010                 struct strvec argv = STRVEC_INIT;
1011                 int res;
1012                 sq_dequote_to_strvec(rev, &argv);
1013                 res = bisect_start(terms, argv.v, argv.nr);
1014                 strvec_clear(&argv);
1015                 return res;
1016         }
1017
1018         if (one_of(p, terms->term_good,
1019            terms->term_bad, "skip", NULL))
1020                 return bisect_write(p, rev, terms, 0);
1021
1022         if (!strcmp(p, "terms")) {
1023                 struct strvec argv = STRVEC_INIT;
1024                 int res;
1025                 sq_dequote_to_strvec(rev, &argv);
1026                 res = bisect_terms(terms, argv.nr == 1 ? argv.v[0] : NULL);
1027                 strvec_clear(&argv);
1028                 return res;
1029         }
1030         error(_("'%s'?? what are you talking about?"), p);
1031
1032         return -1;
1033 }
1034
1035 static enum bisect_error bisect_replay(struct bisect_terms *terms, const char *filename)
1036 {
1037         FILE *fp = NULL;
1038         enum bisect_error res = BISECT_OK;
1039         struct strbuf line = STRBUF_INIT;
1040
1041         if (is_empty_or_missing_file(filename))
1042                 return error(_("cannot read file '%s' for replaying"), filename);
1043
1044         if (bisect_reset(NULL))
1045                 return BISECT_FAILED;
1046
1047         fp = fopen(filename, "r");
1048         if (!fp)
1049                 return BISECT_FAILED;
1050
1051         while ((strbuf_getline(&line, fp) != EOF) && !res)
1052                 res = process_replay_line(terms, &line);
1053
1054         strbuf_release(&line);
1055         fclose(fp);
1056
1057         if (res)
1058                 return BISECT_FAILED;
1059
1060         return bisect_auto_next(terms, NULL);
1061 }
1062
1063 static enum bisect_error bisect_skip(struct bisect_terms *terms, const char **argv, int argc)
1064 {
1065         int i;
1066         enum bisect_error res;
1067         struct strvec argv_state = STRVEC_INIT;
1068
1069         strvec_push(&argv_state, "skip");
1070
1071         for (i = 0; i < argc; i++) {
1072                 const char *dotdot = strstr(argv[i], "..");
1073
1074                 if (dotdot) {
1075                         struct rev_info revs;
1076                         struct commit *commit;
1077
1078                         init_revisions(&revs, NULL);
1079                         setup_revisions(2, argv + i - 1, &revs, NULL);
1080
1081                         if (prepare_revision_walk(&revs))
1082                                 die(_("revision walk setup failed\n"));
1083                         while ((commit = get_revision(&revs)) != NULL)
1084                                 strvec_push(&argv_state,
1085                                                 oid_to_hex(&commit->object.oid));
1086
1087                         reset_revision_walk();
1088                         release_revisions(&revs);
1089                 } else {
1090                         strvec_push(&argv_state, argv[i]);
1091                 }
1092         }
1093         res = bisect_state(terms, argv_state.v, argv_state.nr);
1094
1095         strvec_clear(&argv_state);
1096         return res;
1097 }
1098
1099 static int bisect_visualize(struct bisect_terms *terms, const char **argv, int argc)
1100 {
1101         struct strvec args = STRVEC_INIT;
1102         int flags = RUN_COMMAND_NO_STDIN, res = 0;
1103         struct strbuf sb = STRBUF_INIT;
1104
1105         if (bisect_next_check(terms, NULL) != 0)
1106                 return BISECT_FAILED;
1107
1108         if (!argc) {
1109                 if ((getenv("DISPLAY") || getenv("SESSIONNAME") || getenv("MSYSTEM") ||
1110                      getenv("SECURITYSESSIONID")) && exists_in_PATH("gitk")) {
1111                         strvec_push(&args, "gitk");
1112                 } else {
1113                         strvec_push(&args, "log");
1114                         flags |= RUN_GIT_CMD;
1115                 }
1116         } else {
1117                 if (argv[0][0] == '-') {
1118                         strvec_push(&args, "log");
1119                         flags |= RUN_GIT_CMD;
1120                 } else if (strcmp(argv[0], "tig") && !starts_with(argv[0], "git"))
1121                         flags |= RUN_GIT_CMD;
1122
1123                 strvec_pushv(&args, argv);
1124         }
1125
1126         strvec_pushl(&args, "--bisect", "--", NULL);
1127
1128         strbuf_read_file(&sb, git_path_bisect_names(), 0);
1129         sq_dequote_to_strvec(sb.buf, &args);
1130         strbuf_release(&sb);
1131
1132         res = run_command_v_opt(args.v, flags);
1133         strvec_clear(&args);
1134         return res;
1135 }
1136
1137 static int get_first_good(const char *refname, const struct object_id *oid,
1138                           int flag, void *cb_data)
1139 {
1140         oidcpy(cb_data, oid);
1141         return 1;
1142 }
1143
1144 static int verify_good(const struct bisect_terms *terms,
1145                        const char **quoted_argv)
1146 {
1147         int rc;
1148         enum bisect_error res;
1149         struct object_id good_rev;
1150         struct object_id current_rev;
1151         char *good_glob = xstrfmt("%s-*", terms->term_good);
1152         int no_checkout = ref_exists("BISECT_HEAD");
1153
1154         for_each_glob_ref_in(get_first_good, good_glob, "refs/bisect/",
1155                              &good_rev);
1156         free(good_glob);
1157
1158         if (read_ref(no_checkout ? "BISECT_HEAD" : "HEAD", &current_rev))
1159                 return -1;
1160
1161         res = bisect_checkout(&good_rev, no_checkout);
1162         if (res != BISECT_OK)
1163                 return -1;
1164
1165         printf(_("running %s\n"), quoted_argv[0]);
1166         rc = run_command_v_opt(quoted_argv, RUN_USING_SHELL);
1167
1168         res = bisect_checkout(&current_rev, no_checkout);
1169         if (res != BISECT_OK)
1170                 return -1;
1171
1172         return rc;
1173 }
1174
1175 static int bisect_run(struct bisect_terms *terms, const char **argv, int argc)
1176 {
1177         int res = BISECT_OK;
1178         struct strbuf command = STRBUF_INIT;
1179         struct strvec run_args = STRVEC_INIT;
1180         const char *new_state;
1181         int temporary_stdout_fd, saved_stdout;
1182         int is_first_run = 1;
1183
1184         if (bisect_next_check(terms, NULL))
1185                 return BISECT_FAILED;
1186
1187         if (argc)
1188                 sq_quote_argv(&command, argv);
1189         else {
1190                 error(_("bisect run failed: no command provided."));
1191                 return BISECT_FAILED;
1192         }
1193
1194         strvec_push(&run_args, command.buf);
1195
1196         while (1) {
1197                 printf(_("running %s\n"), command.buf);
1198                 res = run_command_v_opt(run_args.v, RUN_USING_SHELL);
1199
1200                 /*
1201                  * Exit code 126 and 127 can either come from the shell
1202                  * if it was unable to execute or even find the script,
1203                  * or from the script itself.  Check with a known-good
1204                  * revision to avoid trashing the bisect run due to a
1205                  * missing or non-executable script.
1206                  */
1207                 if (is_first_run && (res == 126 || res == 127)) {
1208                         int rc = verify_good(terms, run_args.v);
1209                         is_first_run = 0;
1210                         if (rc < 0) {
1211                                 error(_("unable to verify '%s' on good"
1212                                         " revision"), command.buf);
1213                                 res = BISECT_FAILED;
1214                                 break;
1215                         }
1216                         if (rc == res) {
1217                                 error(_("bogus exit code %d for good revision"),
1218                                       rc);
1219                                 res = BISECT_FAILED;
1220                                 break;
1221                         }
1222                 }
1223
1224                 if (res < 0 || 128 <= res) {
1225                         error(_("bisect run failed: exit code %d from"
1226                                 " '%s' is < 0 or >= 128"), res, command.buf);
1227                         break;
1228                 }
1229
1230                 if (res == 125)
1231                         new_state = "skip";
1232                 else if (!res)
1233                         new_state = terms->term_good;
1234                 else
1235                         new_state = terms->term_bad;
1236
1237                 temporary_stdout_fd = open(git_path_bisect_run(), O_CREAT | O_WRONLY | O_TRUNC, 0666);
1238
1239                 if (temporary_stdout_fd < 0) {
1240                         res = error_errno(_("cannot open file '%s' for writing"), git_path_bisect_run());
1241                         break;
1242                 }
1243
1244                 fflush(stdout);
1245                 saved_stdout = dup(1);
1246                 dup2(temporary_stdout_fd, 1);
1247
1248                 res = bisect_state(terms, &new_state, 1);
1249
1250                 fflush(stdout);
1251                 dup2(saved_stdout, 1);
1252                 close(saved_stdout);
1253                 close(temporary_stdout_fd);
1254
1255                 print_file_to_stdout(git_path_bisect_run());
1256
1257                 if (res == BISECT_ONLY_SKIPPED_LEFT)
1258                         error(_("bisect run cannot continue any more"));
1259                 else if (res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) {
1260                         printf(_("bisect run success"));
1261                         res = BISECT_OK;
1262                 } else if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
1263                         printf(_("bisect found first bad commit"));
1264                         res = BISECT_OK;
1265                 } else if (res) {
1266                         error(_("bisect run failed: 'git bisect--helper --bisect-state"
1267                         " %s' exited with error code %d"), new_state, res);
1268                 } else {
1269                         continue;
1270                 }
1271                 break;
1272         }
1273
1274         strbuf_release(&command);
1275         strvec_clear(&run_args);
1276         return res;
1277 }
1278
1279 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
1280 {
1281         enum {
1282                 BISECT_RESET = 1,
1283                 BISECT_NEXT_CHECK,
1284                 BISECT_TERMS,
1285                 BISECT_START,
1286                 BISECT_AUTOSTART,
1287                 BISECT_NEXT,
1288                 BISECT_STATE,
1289                 BISECT_LOG,
1290                 BISECT_REPLAY,
1291                 BISECT_SKIP,
1292                 BISECT_VISUALIZE,
1293                 BISECT_RUN,
1294         } cmdmode = 0;
1295         int res = 0, nolog = 0;
1296         struct option options[] = {
1297                 OPT_CMDMODE(0, "bisect-reset", &cmdmode,
1298                          N_("reset the bisection state"), BISECT_RESET),
1299                 OPT_CMDMODE(0, "bisect-next-check", &cmdmode,
1300                          N_("check whether bad or good terms exist"), BISECT_NEXT_CHECK),
1301                 OPT_CMDMODE(0, "bisect-terms", &cmdmode,
1302                          N_("print out the bisect terms"), BISECT_TERMS),
1303                 OPT_CMDMODE(0, "bisect-start", &cmdmode,
1304                          N_("start the bisect session"), BISECT_START),
1305                 OPT_CMDMODE(0, "bisect-next", &cmdmode,
1306                          N_("find the next bisection commit"), BISECT_NEXT),
1307                 OPT_CMDMODE(0, "bisect-state", &cmdmode,
1308                          N_("mark the state of ref (or refs)"), BISECT_STATE),
1309                 OPT_CMDMODE(0, "bisect-log", &cmdmode,
1310                          N_("list the bisection steps so far"), BISECT_LOG),
1311                 OPT_CMDMODE(0, "bisect-replay", &cmdmode,
1312                          N_("replay the bisection process from the given file"), BISECT_REPLAY),
1313                 OPT_CMDMODE(0, "bisect-skip", &cmdmode,
1314                          N_("skip some commits for checkout"), BISECT_SKIP),
1315                 OPT_CMDMODE(0, "bisect-visualize", &cmdmode,
1316                          N_("visualize the bisection"), BISECT_VISUALIZE),
1317                 OPT_CMDMODE(0, "bisect-run", &cmdmode,
1318                          N_("use <cmd>... to automatically bisect"), BISECT_RUN),
1319                 OPT_BOOL(0, "no-log", &nolog,
1320                          N_("no log for BISECT_WRITE")),
1321                 OPT_END()
1322         };
1323         struct bisect_terms terms = { .term_good = NULL, .term_bad = NULL };
1324
1325         argc = parse_options(argc, argv, prefix, options,
1326                              git_bisect_helper_usage,
1327                              PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_UNKNOWN);
1328
1329         if (!cmdmode)
1330                 usage_with_options(git_bisect_helper_usage, options);
1331
1332         switch (cmdmode) {
1333         case BISECT_RESET:
1334                 if (argc > 1)
1335                         return error(_("--bisect-reset requires either no argument or a commit"));
1336                 res = bisect_reset(argc ? argv[0] : NULL);
1337                 break;
1338         case BISECT_TERMS:
1339                 if (argc > 1)
1340                         return error(_("--bisect-terms requires 0 or 1 argument"));
1341                 res = bisect_terms(&terms, argc == 1 ? argv[0] : NULL);
1342                 break;
1343         case BISECT_START:
1344                 set_terms(&terms, "bad", "good");
1345                 res = bisect_start(&terms, argv, argc);
1346                 break;
1347         case BISECT_NEXT:
1348                 if (argc)
1349                         return error(_("--bisect-next requires 0 arguments"));
1350                 get_terms(&terms);
1351                 res = bisect_next(&terms, prefix);
1352                 break;
1353         case BISECT_STATE:
1354                 set_terms(&terms, "bad", "good");
1355                 get_terms(&terms);
1356                 res = bisect_state(&terms, argv, argc);
1357                 break;
1358         case BISECT_LOG:
1359                 if (argc)
1360                         return error(_("--bisect-log requires 0 arguments"));
1361                 res = bisect_log();
1362                 break;
1363         case BISECT_REPLAY:
1364                 if (argc != 1)
1365                         return error(_("no logfile given"));
1366                 set_terms(&terms, "bad", "good");
1367                 res = bisect_replay(&terms, argv[0]);
1368                 break;
1369         case BISECT_SKIP:
1370                 set_terms(&terms, "bad", "good");
1371                 get_terms(&terms);
1372                 res = bisect_skip(&terms, argv, argc);
1373                 break;
1374         case BISECT_VISUALIZE:
1375                 get_terms(&terms);
1376                 res = bisect_visualize(&terms, argv, argc);
1377                 break;
1378         case BISECT_RUN:
1379                 if (!argc)
1380                         return error(_("bisect run failed: no command provided."));
1381                 get_terms(&terms);
1382                 res = bisect_run(&terms, argv, argc);
1383                 break;
1384         default:
1385                 BUG("unknown subcommand %d", cmdmode);
1386         }
1387         free_terms(&terms);
1388
1389         /*
1390          * Handle early success
1391          * From check_merge_bases > check_good_are_ancestors_of_bad > bisect_next_all
1392          */
1393         if ((res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) || (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND))
1394                 res = BISECT_OK;
1395
1396         return -res;
1397 }