git.oblomov.eu Git - git/blob - builtin/rebase.c

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #include "builtin.h"
   8 #include "run-command.h"
   9 #include "exec-cmd.h"
  10 #include "argv-array.h"
  11 #include "dir.h"
  12 #include "packfile.h"
  13 #include "refs.h"
  14 #include "quote.h"
  15 #include "config.h"
  16 #include "cache-tree.h"
  17 #include "unpack-trees.h"
  18 #include "lockfile.h"
  19 #include "parse-options.h"
  20 #include "commit.h"
  21 #include "diff.h"
  22 #include "wt-status.h"
  23 #include "revision.h"
  24 #include "commit-reach.h"
  25 #include "rerere.h"
  26
  27 static char const * const builtin_rebase_usage[] = {
  28         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  29                 "[<upstream>] [<branch>]"),
  30         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  31                 "--root [<branch>]"),
  32         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  33         NULL
  34 };
  35
  36 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  37 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  38
  39 enum rebase_type {
  40         REBASE_UNSPECIFIED = -1,
  41         REBASE_AM,
  42         REBASE_MERGE,
  43         REBASE_INTERACTIVE,
  44         REBASE_PRESERVE_MERGES
  45 };
  46
  47 static int use_builtin_rebase(void)
  48 {
  49         struct child_process cp = CHILD_PROCESS_INIT;
  50         struct strbuf out = STRBUF_INIT;
  51         int ret;
  52
  53         argv_array_pushl(&cp.args,
  54                          "config", "--bool", "rebase.usebuiltin", NULL);
  55         cp.git_cmd = 1;
  56         if (capture_command(&cp, &out, 6)) {
  57                 strbuf_release(&out);
  58                 return 0;
  59         }
  60
  61         strbuf_trim(&out);
  62         ret = !strcmp("true", out.buf);
  63         strbuf_release(&out);
  64         return ret;
  65 }
  66
  67 struct rebase_options {
  68         enum rebase_type type;
  69         const char *state_dir;
  70         struct commit *upstream;
  71         const char *upstream_name;
  72         const char *upstream_arg;
  73         char *head_name;
  74         struct object_id orig_head;
  75         struct commit *onto;
  76         const char *onto_name;
  77         const char *revisions;
  78         const char *switch_to;
  79         int root;
  80         struct object_id *squash_onto;
  81         struct commit *restrict_revision;
  82         int dont_finish_rebase;
  83         enum {
  84                 REBASE_NO_QUIET = 1<<0,
  85                 REBASE_VERBOSE = 1<<1,
  86                 REBASE_DIFFSTAT = 1<<2,
  87                 REBASE_FORCE = 1<<3,
  88                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  89         } flags;
  90         struct strbuf git_am_opt;
  91         const char *action;
  92         int signoff;
  93         int allow_rerere_autoupdate;
  94         int keep_empty;
  95         int autosquash;
  96         char *gpg_sign_opt;
  97         int autostash;
  98         char *cmd;
  99         int allow_empty_message;
 100         int rebase_merges, rebase_cousins;
 101         char *strategy, *strategy_opts;
 102 };
 103
 104 static int is_interactive(struct rebase_options *opts)
 105 {
 106         return opts->type == REBASE_INTERACTIVE ||
 107                 opts->type == REBASE_PRESERVE_MERGES;
 108 }
 109
 110 static void imply_interactive(struct rebase_options *opts, const char *option)
 111 {
 112         switch (opts->type) {
 113         case REBASE_AM:
 114                 die(_("%s requires an interactive rebase"), option);
 115                 break;
 116         case REBASE_INTERACTIVE:
 117         case REBASE_PRESERVE_MERGES:
 118                 break;
 119         case REBASE_MERGE:
 120                 /* we silently *upgrade* --merge to --interactive if needed */
 121         default:
 122                 opts->type = REBASE_INTERACTIVE; /* implied */
 123                 break;
 124         }
 125 }
 126
 127 /* Returns the filename prefixed by the state_dir */
 128 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 129 {
 130         static struct strbuf path = STRBUF_INIT;
 131         static size_t prefix_len;
 132
 133         if (!prefix_len) {
 134                 strbuf_addf(&path, "%s/", opts->state_dir);
 135                 prefix_len = path.len;
 136         }
 137
 138         strbuf_setlen(&path, prefix_len);
 139         strbuf_addstr(&path, filename);
 140         return path.buf;
 141 }
 142
 143 /* Read one file, then strip line endings */
 144 static int read_one(const char *path, struct strbuf *buf)
 145 {
 146         if (strbuf_read_file(buf, path, 0) < 0)
 147                 return error_errno(_("could not read '%s'"), path);
 148         strbuf_trim_trailing_newline(buf);
 149         return 0;
 150 }
 151
 152 /* Initialize the rebase options from the state directory. */
 153 static int read_basic_state(struct rebase_options *opts)
 154 {
 155         struct strbuf head_name = STRBUF_INIT;
 156         struct strbuf buf = STRBUF_INIT;
 157         struct object_id oid;
 158
 159         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 160             read_one(state_dir_path("onto", opts), &buf))
 161                 return -1;
 162         opts->head_name = starts_with(head_name.buf, "refs/") ?
 163                 xstrdup(head_name.buf) : NULL;
 164         strbuf_release(&head_name);
 165         if (get_oid(buf.buf, &oid))
 166                 return error(_("could not get 'onto': '%s'"), buf.buf);
 167         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 168
 169         /*
 170          * We always write to orig-head, but interactive rebase used to write to
 171          * head. Fall back to reading from head to cover for the case that the
 172          * user upgraded git with an ongoing interactive rebase.
 173          */
 174         strbuf_reset(&buf);
 175         if (file_exists(state_dir_path("orig-head", opts))) {
 176                 if (read_one(state_dir_path("orig-head", opts), &buf))
 177                         return -1;
 178         } else if (read_one(state_dir_path("head", opts), &buf))
 179                 return -1;
 180         if (get_oid(buf.buf, &opts->orig_head))
 181                 return error(_("invalid orig-head: '%s'"), buf.buf);
 182
 183         strbuf_reset(&buf);
 184         if (read_one(state_dir_path("quiet", opts), &buf))
 185                 return -1;
 186         if (buf.len)
 187                 opts->flags &= ~REBASE_NO_QUIET;
 188         else
 189                 opts->flags |= REBASE_NO_QUIET;
 190
 191         if (file_exists(state_dir_path("verbose", opts)))
 192                 opts->flags |= REBASE_VERBOSE;
 193
 194         if (file_exists(state_dir_path("signoff", opts))) {
 195                 opts->signoff = 1;
 196                 opts->flags |= REBASE_FORCE;
 197         }
 198
 199         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 200                 strbuf_reset(&buf);
 201                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 202                             &buf))
 203                         return -1;
 204                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 205                         opts->allow_rerere_autoupdate = 1;
 206                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 207                         opts->allow_rerere_autoupdate = 0;
 208                 else
 209                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 210                                   "'%s'"), buf.buf);
 211         } else
 212                 opts->allow_rerere_autoupdate = -1;
 213
 214         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 215                 strbuf_reset(&buf);
 216                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 217                             &buf))
 218                         return -1;
 219                 free(opts->gpg_sign_opt);
 220                 opts->gpg_sign_opt = xstrdup(buf.buf);
 221         }
 222
 223         if (file_exists(state_dir_path("strategy", opts))) {
 224                 strbuf_reset(&buf);
 225                 if (read_one(state_dir_path("strategy", opts), &buf))
 226                         return -1;
 227                 free(opts->strategy);
 228                 opts->strategy = xstrdup(buf.buf);
 229         }
 230
 231         if (file_exists(state_dir_path("strategy_opts", opts))) {
 232                 strbuf_reset(&buf);
 233                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 234                         return -1;
 235                 free(opts->strategy_opts);
 236                 opts->strategy_opts = xstrdup(buf.buf);
 237         }
 238
 239         strbuf_release(&buf);
 240
 241         return 0;
 242 }
 243
 244 static int apply_autostash(struct rebase_options *opts)
 245 {
 246         const char *path = state_dir_path("autostash", opts);
 247         struct strbuf autostash = STRBUF_INIT;
 248         struct child_process stash_apply = CHILD_PROCESS_INIT;
 249
 250         if (!file_exists(path))
 251                 return 0;
 252
 253         if (read_one(state_dir_path("autostash", opts), &autostash))
 254                 return error(_("Could not read '%s'"), path);
 255         argv_array_pushl(&stash_apply.args,
 256                          "stash", "apply", autostash.buf, NULL);
 257         stash_apply.git_cmd = 1;
 258         stash_apply.no_stderr = stash_apply.no_stdout =
 259                 stash_apply.no_stdin = 1;
 260         if (!run_command(&stash_apply))
 261                 printf(_("Applied autostash.\n"));
 262         else {
 263                 struct argv_array args = ARGV_ARRAY_INIT;
 264                 int res = 0;
 265
 266                 argv_array_pushl(&args,
 267                                  "stash", "store", "-m", "autostash", "-q",
 268                                  autostash.buf, NULL);
 269                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 270                         res = error(_("Cannot store %s"), autostash.buf);
 271                 argv_array_clear(&args);
 272                 strbuf_release(&autostash);
 273                 if (res)
 274                         return res;
 275
 276                 fprintf(stderr,
 277                         _("Applying autostash resulted in conflicts.\n"
 278                           "Your changes are safe in the stash.\n"
 279                           "You can run \"git stash pop\" or \"git stash drop\" "
 280                           "at any time.\n"));
 281         }
 282
 283         strbuf_release(&autostash);
 284         return 0;
 285 }
 286
 287 static int finish_rebase(struct rebase_options *opts)
 288 {
 289         struct strbuf dir = STRBUF_INIT;
 290         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 291
 292         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 293         apply_autostash(opts);
 294         close_all_packs(the_repository->objects);
 295         /*
 296          * We ignore errors in 'gc --auto', since the
 297          * user should see them.
 298          */
 299         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 300         strbuf_addstr(&dir, opts->state_dir);
 301         remove_dir_recursively(&dir, 0);
 302         strbuf_release(&dir);
 303
 304         return 0;
 305 }
 306
 307 static struct commit *peel_committish(const char *name)
 308 {
 309         struct object *obj;
 310         struct object_id oid;
 311
 312         if (get_oid(name, &oid))
 313                 return NULL;
 314         obj = parse_object(the_repository, &oid);
 315         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 316 }
 317
 318 static void add_var(struct strbuf *buf, const char *name, const char *value)
 319 {
 320         if (!value)
 321                 strbuf_addf(buf, "unset %s; ", name);
 322         else {
 323                 strbuf_addf(buf, "%s=", name);
 324                 sq_quote_buf(buf, value);
 325                 strbuf_addstr(buf, "; ");
 326         }
 327 }
 328
 329 static int run_specific_rebase(struct rebase_options *opts)
 330 {
 331         const char *argv[] = { NULL, NULL };
 332         struct strbuf script_snippet = STRBUF_INIT;
 333         int status;
 334         const char *backend, *backend_func;
 335
 336         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 337         add_var(&script_snippet, "state_dir", opts->state_dir);
 338
 339         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 340         add_var(&script_snippet, "upstream", opts->upstream ?
 341                 oid_to_hex(&opts->upstream->object.oid) : NULL);
 342         add_var(&script_snippet, "head_name",
 343                 opts->head_name ? opts->head_name : "detached HEAD");
 344         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 345         add_var(&script_snippet, "onto", opts->onto ?
 346                 oid_to_hex(&opts->onto->object.oid) : NULL);
 347         add_var(&script_snippet, "onto_name", opts->onto_name);
 348         add_var(&script_snippet, "revisions", opts->revisions);
 349         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 350                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 351         add_var(&script_snippet, "GIT_QUIET",
 352                 opts->flags & REBASE_NO_QUIET ? "" : "t");
 353         add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
 354         add_var(&script_snippet, "verbose",
 355                 opts->flags & REBASE_VERBOSE ? "t" : "");
 356         add_var(&script_snippet, "diffstat",
 357                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
 358         add_var(&script_snippet, "force_rebase",
 359                 opts->flags & REBASE_FORCE ? "t" : "");
 360         if (opts->switch_to)
 361                 add_var(&script_snippet, "switch_to", opts->switch_to);
 362         add_var(&script_snippet, "action", opts->action ? opts->action : "");
 363         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 364         add_var(&script_snippet, "allow_rerere_autoupdate",
 365                 opts->allow_rerere_autoupdate < 0 ? "" :
 366                 opts->allow_rerere_autoupdate ?
 367                 "--rerere-autoupdate" : "--no-rerere-autoupdate");
 368         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 369         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 370         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 371         add_var(&script_snippet, "cmd", opts->cmd);
 372         add_var(&script_snippet, "allow_empty_message",
 373                 opts->allow_empty_message ?  "--allow-empty-message" : "");
 374         add_var(&script_snippet, "rebase_merges",
 375                 opts->rebase_merges ? "t" : "");
 376         add_var(&script_snippet, "rebase_cousins",
 377                 opts->rebase_cousins ? "t" : "");
 378         add_var(&script_snippet, "strategy", opts->strategy);
 379         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 380         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 381         add_var(&script_snippet, "squash_onto",
 382                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 383
 384         switch (opts->type) {
 385         case REBASE_AM:
 386                 backend = "git-rebase--am";
 387                 backend_func = "git_rebase__am";
 388                 break;
 389         case REBASE_INTERACTIVE:
 390                 backend = "git-rebase--interactive";
 391                 backend_func = "git_rebase__interactive";
 392                 break;
 393         case REBASE_MERGE:
 394                 backend = "git-rebase--merge";
 395                 backend_func = "git_rebase__merge";
 396                 break;
 397         case REBASE_PRESERVE_MERGES:
 398                 backend = "git-rebase--preserve-merges";
 399                 backend_func = "git_rebase__preserve_merges";
 400                 break;
 401         default:
 402                 BUG("Unhandled rebase type %d", opts->type);
 403                 break;
 404         }
 405
 406         strbuf_addf(&script_snippet,
 407                     ". git-sh-setup && . git-rebase--common &&"
 408                     " . %s && %s", backend, backend_func);
 409         argv[0] = script_snippet.buf;
 410
 411         status = run_command_v_opt(argv, RUN_USING_SHELL);
 412         if (opts->dont_finish_rebase)
 413                 ; /* do nothing */
 414         else if (status == 0) {
 415                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 416                         finish_rebase(opts);
 417         } else if (status == 2) {
 418                 struct strbuf dir = STRBUF_INIT;
 419
 420                 apply_autostash(opts);
 421                 strbuf_addstr(&dir, opts->state_dir);
 422                 remove_dir_recursively(&dir, 0);
 423                 strbuf_release(&dir);
 424                 die("Nothing to do");
 425         }
 426
 427         strbuf_release(&script_snippet);
 428
 429         return status ? -1 : 0;
 430 }
 431
 432 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 433
 434 static int reset_head(struct object_id *oid, const char *action,
 435                       const char *switch_to_branch, int detach_head)
 436 {
 437         struct object_id head_oid;
 438         struct tree_desc desc;
 439         struct lock_file lock = LOCK_INIT;
 440         struct unpack_trees_options unpack_tree_opts;
 441         struct tree *tree;
 442         const char *reflog_action;
 443         struct strbuf msg = STRBUF_INIT;
 444         size_t prefix_len;
 445         struct object_id *orig = NULL, oid_orig,
 446                 *old_orig = NULL, oid_old_orig;
 447         int ret = 0;
 448
 449         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 450                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 451
 452         if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 453                 return -1;
 454
 455         if (!oid) {
 456                 if (get_oid("HEAD", &head_oid)) {
 457                         rollback_lock_file(&lock);
 458                         return error(_("could not determine HEAD revision"));
 459                 }
 460                 oid = &head_oid;
 461         }
 462
 463         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 464         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 465         unpack_tree_opts.head_idx = 1;
 466         unpack_tree_opts.src_index = the_repository->index;
 467         unpack_tree_opts.dst_index = the_repository->index;
 468         unpack_tree_opts.fn = oneway_merge;
 469         unpack_tree_opts.update = 1;
 470         unpack_tree_opts.merge = 1;
 471         if (!detach_head)
 472                 unpack_tree_opts.reset = 1;
 473
 474         if (read_index_unmerged(the_repository->index) < 0) {
 475                 rollback_lock_file(&lock);
 476                 return error(_("could not read index"));
 477         }
 478
 479         if (!fill_tree_descriptor(&desc, oid)) {
 480                 error(_("failed to find tree of %s"), oid_to_hex(oid));
 481                 rollback_lock_file(&lock);
 482                 free((void *)desc.buffer);
 483                 return -1;
 484         }
 485
 486         if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 487                 rollback_lock_file(&lock);
 488                 free((void *)desc.buffer);
 489                 return -1;
 490         }
 491
 492         tree = parse_tree_indirect(oid);
 493         prime_cache_tree(the_repository->index, tree);
 494
 495         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 496                 ret = error(_("could not write index"));
 497         free((void *)desc.buffer);
 498
 499         if (ret)
 500                 return ret;
 501
 502         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 503         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 504         prefix_len = msg.len;
 505
 506         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 507                 old_orig = &oid_old_orig;
 508         if (!get_oid("HEAD", &oid_orig)) {
 509                 orig = &oid_orig;
 510                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 511                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 512                            UPDATE_REFS_MSG_ON_ERR);
 513         } else if (old_orig)
 514                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 515         strbuf_setlen(&msg, prefix_len);
 516         strbuf_addstr(&msg, "updating HEAD");
 517         if (!switch_to_branch)
 518                 ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 519                                  UPDATE_REFS_MSG_ON_ERR);
 520         else {
 521                 ret = create_symref("HEAD", switch_to_branch, msg.buf);
 522                 if (!ret)
 523                         ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 524                                          UPDATE_REFS_MSG_ON_ERR);
 525         }
 526
 527         strbuf_release(&msg);
 528         return ret;
 529 }
 530
 531 static int rebase_config(const char *var, const char *value, void *data)
 532 {
 533         struct rebase_options *opts = data;
 534
 535         if (!strcmp(var, "rebase.stat")) {
 536                 if (git_config_bool(var, value))
 537                         opts->flags |= REBASE_DIFFSTAT;
 538                 else
 539                         opts->flags &= !REBASE_DIFFSTAT;
 540                 return 0;
 541         }
 542
 543         if (!strcmp(var, "rebase.autosquash")) {
 544                 opts->autosquash = git_config_bool(var, value);
 545                 return 0;
 546         }
 547
 548         if (!strcmp(var, "commit.gpgsign")) {
 549                 free(opts->gpg_sign_opt);
 550                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 551                         xstrdup("-S") : NULL;
 552                 return 0;
 553         }
 554
 555         if (!strcmp(var, "rebase.autostash")) {
 556                 opts->autostash = git_config_bool(var, value);
 557                 return 0;
 558         }
 559
 560         return git_default_config(var, value, data);
 561 }
 562
 563 /*
 564  * Determines whether the commits in from..to are linear, i.e. contain
 565  * no merge commits. This function *expects* `from` to be an ancestor of
 566  * `to`.
 567  */
 568 static int is_linear_history(struct commit *from, struct commit *to)
 569 {
 570         while (to && to != from) {
 571                 parse_commit(to);
 572                 if (!to->parents)
 573                         return 1;
 574                 if (to->parents->next)
 575                         return 0;
 576                 to = to->parents->item;
 577         }
 578         return 1;
 579 }
 580
 581 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 582                             struct object_id *merge_base)
 583 {
 584         struct commit *head = lookup_commit(the_repository, head_oid);
 585         struct commit_list *merge_bases;
 586         int res;
 587
 588         if (!head)
 589                 return 0;
 590
 591         merge_bases = get_merge_bases(onto, head);
 592         if (merge_bases && !merge_bases->next) {
 593                 oidcpy(merge_base, &merge_bases->item->object.oid);
 594                 res = !oidcmp(merge_base, &onto->object.oid);
 595         } else {
 596                 oidcpy(merge_base, &null_oid);
 597                 res = 0;
 598         }
 599         free_commit_list(merge_bases);
 600         return res && is_linear_history(onto, head);
 601 }
 602
 603 /* -i followed by -m is still -i */
 604 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 605 {
 606         struct rebase_options *opts = opt->value;
 607
 608         if (!is_interactive(opts))
 609                 opts->type = REBASE_MERGE;
 610
 611         return 0;
 612 }
 613
 614 /* -i followed by -p is still explicitly interactive, but -p alone is not */
 615 static int parse_opt_interactive(const struct option *opt, const char *arg,
 616                                  int unset)
 617 {
 618         struct rebase_options *opts = opt->value;
 619
 620         opts->type = REBASE_INTERACTIVE;
 621         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 622
 623         return 0;
 624 }
 625
 626 int cmd_rebase(int argc, const char **argv, const char *prefix)
 627 {
 628         struct rebase_options options = {
 629                 .type = REBASE_UNSPECIFIED,
 630                 .flags = REBASE_NO_QUIET,
 631                 .git_am_opt = STRBUF_INIT,
 632                 .allow_rerere_autoupdate  = -1,
 633                 .allow_empty_message = 1,
 634         };
 635         const char *branch_name;
 636         int ret, flags, total_argc, in_progress = 0;
 637         int ok_to_skip_pre_rebase = 0;
 638         struct strbuf msg = STRBUF_INIT;
 639         struct strbuf revisions = STRBUF_INIT;
 640         struct strbuf buf = STRBUF_INIT;
 641         struct object_id merge_base;
 642         enum {
 643                 NO_ACTION,
 644                 ACTION_CONTINUE,
 645                 ACTION_SKIP,
 646                 ACTION_ABORT,
 647                 ACTION_QUIT,
 648                 ACTION_EDIT_TODO,
 649                 ACTION_SHOW_CURRENT_PATCH,
 650         } action = NO_ACTION;
 651         int committer_date_is_author_date = 0;
 652         int ignore_date = 0;
 653         int ignore_whitespace = 0;
 654         const char *gpg_sign = NULL;
 655         int opt_c = -1;
 656         struct string_list whitespace = STRING_LIST_INIT_NODUP;
 657         struct string_list exec = STRING_LIST_INIT_NODUP;
 658         const char *rebase_merges = NULL;
 659         int fork_point = -1;
 660         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 661         struct object_id squash_onto;
 662         char *squash_onto_name = NULL;
 663         struct option builtin_rebase_options[] = {
 664                 OPT_STRING(0, "onto", &options.onto_name,
 665                            N_("revision"),
 666                            N_("rebase onto given branch instead of upstream")),
 667                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 668                          N_("allow pre-rebase hook to run")),
 669                 OPT_NEGBIT('q', "quiet", &options.flags,
 670                            N_("be quiet. implies --no-stat"),
 671                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 672                 OPT_BIT('v', "verbose", &options.flags,
 673                         N_("display a diffstat of what changed upstream"),
 674                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 675                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 676                         N_("do not show diffstat of what changed upstream"),
 677                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 678                 OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
 679                          N_("passed to 'git apply'")),
 680                 OPT_BOOL(0, "signoff", &options.signoff,
 681                          N_("add a Signed-off-by: line to each commit")),
 682                 OPT_BOOL(0, "committer-date-is-author-date",
 683                          &committer_date_is_author_date,
 684                          N_("passed to 'git am'")),
 685                 OPT_BOOL(0, "ignore-date", &ignore_date,
 686                          N_("passed to 'git am'")),
 687                 OPT_BIT('f', "force-rebase", &options.flags,
 688                         N_("cherry-pick all commits, even if unchanged"),
 689                         REBASE_FORCE),
 690                 OPT_BIT(0, "no-ff", &options.flags,
 691                         N_("cherry-pick all commits, even if unchanged"),
 692                         REBASE_FORCE),
 693                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
 694                             ACTION_CONTINUE),
 695                 OPT_CMDMODE(0, "skip", &action,
 696                             N_("skip current patch and continue"), ACTION_SKIP),
 697                 OPT_CMDMODE(0, "abort", &action,
 698                             N_("abort and check out the original branch"),
 699                             ACTION_ABORT),
 700                 OPT_CMDMODE(0, "quit", &action,
 701                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
 702                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 703                             "during an interactive rebase"), ACTION_EDIT_TODO),
 704                 OPT_CMDMODE(0, "show-current-patch", &action,
 705                             N_("show the patch file being applied or merged"),
 706                             ACTION_SHOW_CURRENT_PATCH),
 707                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 708                         N_("use merging strategies to rebase"),
 709                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 710                         parse_opt_merge },
 711                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 712                         N_("let the user edit the list of commits to rebase"),
 713                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 714                         parse_opt_interactive },
 715                 OPT_SET_INT('p', "preserve-merges", &options.type,
 716                             N_("try to recreate merges instead of ignoring "
 717                                "them"), REBASE_PRESERVE_MERGES),
 718                 OPT_BOOL(0, "rerere-autoupdate",
 719                          &options.allow_rerere_autoupdate,
 720                          N_("allow rerere to update index  with resolved "
 721                             "conflict")),
 722                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
 723                          N_("preserve empty commits during rebase")),
 724                 OPT_BOOL(0, "autosquash", &options.autosquash,
 725                          N_("move commits that begin with "
 726                             "squash!/fixup! under -i")),
 727                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 728                         N_("GPG-sign commits"),
 729                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 730                 OPT_STRING_LIST(0, "whitespace", &whitespace,
 731                                 N_("whitespace"), N_("passed to 'git apply'")),
 732                 OPT_SET_INT('C', NULL, &opt_c, N_("passed to 'git apply'"),
 733                             REBASE_AM),
 734                 OPT_BOOL(0, "autostash", &options.autostash,
 735                          N_("automatically stash/stash pop before and after")),
 736                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 737                                 N_("add exec lines after each commit of the "
 738                                    "editable list")),
 739                 OPT_BOOL(0, "allow-empty-message",
 740                          &options.allow_empty_message,
 741                          N_("allow rebasing commits with empty messages")),
 742                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 743                         N_("mode"),
 744                         N_("try to rebase merges instead of skipping them"),
 745                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 746                 OPT_BOOL(0, "fork-point", &fork_point,
 747                          N_("use 'merge-base --fork-point' to refine upstream")),
 748                 OPT_STRING('s', "strategy", &options.strategy,
 749                            N_("strategy"), N_("use the given merge strategy")),
 750                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 751                                 N_("option"),
 752                                 N_("pass the argument through to the merge "
 753                                    "strategy")),
 754                 OPT_BOOL(0, "root", &options.root,
 755                          N_("rebase all reachable commits up to the root(s)")),
 756                 OPT_END(),
 757         };
 758
 759         /*
 760          * NEEDSWORK: Once the builtin rebase has been tested enough
 761          * and git-legacy-rebase.sh is retired to contrib/, this preamble
 762          * can be removed.
 763          */
 764
 765         if (!use_builtin_rebase()) {
 766                 const char *path = mkpath("%s/git-legacy-rebase",
 767                                           git_exec_path());
 768
 769                 if (sane_execvp(path, (char **)argv) < 0)
 770                         die_errno(_("could not exec %s"), path);
 771                 else
 772                         BUG("sane_execvp() returned???");
 773         }
 774
 775         if (argc == 2 && !strcmp(argv[1], "-h"))
 776                 usage_with_options(builtin_rebase_usage,
 777                                    builtin_rebase_options);
 778
 779         prefix = setup_git_directory();
 780         trace_repo_setup(prefix);
 781         setup_work_tree();
 782
 783         git_config(rebase_config, &options);
 784
 785         strbuf_reset(&buf);
 786         strbuf_addf(&buf, "%s/applying", apply_dir());
 787         if(file_exists(buf.buf))
 788                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
 789
 790         if (is_directory(apply_dir())) {
 791                 options.type = REBASE_AM;
 792                 options.state_dir = apply_dir();
 793         } else if (is_directory(merge_dir())) {
 794                 strbuf_reset(&buf);
 795                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
 796                 if (is_directory(buf.buf)) {
 797                         options.type = REBASE_PRESERVE_MERGES;
 798                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 799                 } else {
 800                         strbuf_reset(&buf);
 801                         strbuf_addf(&buf, "%s/interactive", merge_dir());
 802                         if(file_exists(buf.buf)) {
 803                                 options.type = REBASE_INTERACTIVE;
 804                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 805                         } else
 806                                 options.type = REBASE_MERGE;
 807                 }
 808                 options.state_dir = merge_dir();
 809         }
 810
 811         if (options.type != REBASE_UNSPECIFIED)
 812                 in_progress = 1;
 813
 814         total_argc = argc;
 815         argc = parse_options(argc, argv, prefix,
 816                              builtin_rebase_options,
 817                              builtin_rebase_usage, 0);
 818
 819         if (action != NO_ACTION && total_argc != 2) {
 820                 usage_with_options(builtin_rebase_usage,
 821                                    builtin_rebase_options);
 822         }
 823
 824         if (argc > 2)
 825                 usage_with_options(builtin_rebase_usage,
 826                                    builtin_rebase_options);
 827
 828         if (action != NO_ACTION && !in_progress)
 829                 die(_("No rebase in progress?"));
 830
 831         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 832                 die(_("The --edit-todo action can only be used during "
 833                       "interactive rebase."));
 834
 835         switch (action) {
 836         case ACTION_CONTINUE: {
 837                 struct object_id head;
 838                 struct lock_file lock_file = LOCK_INIT;
 839                 int fd;
 840
 841                 options.action = "continue";
 842
 843                 /* Sanity check */
 844                 if (get_oid("HEAD", &head))
 845                         die(_("Cannot read HEAD"));
 846
 847                 fd = hold_locked_index(&lock_file, 0);
 848                 if (read_index(the_repository->index) < 0)
 849                         die(_("could not read index"));
 850                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
 851                               NULL);
 852                 if (0 <= fd)
 853                         update_index_if_able(the_repository->index,
 854                                              &lock_file);
 855                 rollback_lock_file(&lock_file);
 856
 857                 if (has_unstaged_changes(1)) {
 858                         puts(_("You must edit all merge conflicts and then\n"
 859                                "mark them as resolved using git add"));
 860                         exit(1);
 861                 }
 862                 if (read_basic_state(&options))
 863                         exit(1);
 864                 goto run_rebase;
 865         }
 866         case ACTION_SKIP: {
 867                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 868
 869                 options.action = "skip";
 870
 871                 rerere_clear(&merge_rr);
 872                 string_list_clear(&merge_rr, 1);
 873
 874                 if (reset_head(NULL, "reset", NULL, 0) < 0)
 875                         die(_("could not discard worktree changes"));
 876                 if (read_basic_state(&options))
 877                         exit(1);
 878                 goto run_rebase;
 879         }
 880         case ACTION_ABORT: {
 881                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 882                 options.action = "abort";
 883
 884                 rerere_clear(&merge_rr);
 885                 string_list_clear(&merge_rr, 1);
 886
 887                 if (read_basic_state(&options))
 888                         exit(1);
 889                 if (reset_head(&options.orig_head, "reset",
 890                                options.head_name, 0) < 0)
 891                         die(_("could not move back to %s"),
 892                             oid_to_hex(&options.orig_head));
 893                 ret = finish_rebase(&options);
 894                 goto cleanup;
 895         }
 896         case ACTION_QUIT: {
 897                 strbuf_reset(&buf);
 898                 strbuf_addstr(&buf, options.state_dir);
 899                 ret = !!remove_dir_recursively(&buf, 0);
 900                 if (ret)
 901                         die(_("could not remove '%s'"), options.state_dir);
 902                 goto cleanup;
 903         }
 904         case ACTION_EDIT_TODO:
 905                 options.action = "edit-todo";
 906                 options.dont_finish_rebase = 1;
 907                 goto run_rebase;
 908         case ACTION_SHOW_CURRENT_PATCH:
 909                 options.action = "show-current-patch";
 910                 options.dont_finish_rebase = 1;
 911                 goto run_rebase;
 912         case NO_ACTION:
 913                 break;
 914         default:
 915                 BUG("action: %d", action);
 916         }
 917
 918         /* Make sure no rebase is in progress */
 919         if (in_progress) {
 920                 const char *last_slash = strrchr(options.state_dir, '/');
 921                 const char *state_dir_base =
 922                         last_slash ? last_slash + 1 : options.state_dir;
 923                 const char *cmd_live_rebase =
 924                         "git rebase (--continue | --abort | --skip)";
 925                 strbuf_reset(&buf);
 926                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
 927                 die(_("It seems that there is already a %s directory, and\n"
 928                       "I wonder if you are in the middle of another rebase.  "
 929                       "If that is the\n"
 930                       "case, please try\n\t%s\n"
 931                       "If that is not the case, please\n\t%s\n"
 932                       "and run me again.  I am stopping in case you still "
 933                       "have something\n"
 934                       "valuable there.\n"),
 935                     state_dir_base, cmd_live_rebase, buf.buf);
 936         }
 937
 938         if (!(options.flags & REBASE_NO_QUIET))
 939                 strbuf_addstr(&options.git_am_opt, " -q");
 940
 941         if (committer_date_is_author_date) {
 942                 strbuf_addstr(&options.git_am_opt,
 943                               " --committer-date-is-author-date");
 944                 options.flags |= REBASE_FORCE;
 945         }
 946
 947         if (ignore_whitespace)
 948                 strbuf_addstr(&options.git_am_opt, " --ignore-whitespace");
 949
 950         if (ignore_date) {
 951                 strbuf_addstr(&options.git_am_opt, " --ignore-date");
 952                 options.flags |= REBASE_FORCE;
 953         }
 954
 955         if (options.keep_empty)
 956                 imply_interactive(&options, "--keep-empty");
 957
 958         if (gpg_sign) {
 959                 free(options.gpg_sign_opt);
 960                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
 961         }
 962
 963         if (opt_c >= 0)
 964                 strbuf_addf(&options.git_am_opt, " -C%d", opt_c);
 965
 966         if (whitespace.nr) {
 967                 int i;
 968
 969                 for (i = 0; i < whitespace.nr; i++) {
 970                         const char *item = whitespace.items[i].string;
 971
 972                         strbuf_addf(&options.git_am_opt, " --whitespace=%s",
 973                                     item);
 974
 975                         if ((!strcmp(item, "fix")) || (!strcmp(item, "strip")))
 976                                 options.flags |= REBASE_FORCE;
 977                 }
 978         }
 979
 980         if (exec.nr) {
 981                 int i;
 982
 983                 imply_interactive(&options, "--exec");
 984
 985                 strbuf_reset(&buf);
 986                 for (i = 0; i < exec.nr; i++)
 987                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
 988                 options.cmd = xstrdup(buf.buf);
 989         }
 990
 991         if (rebase_merges) {
 992                 if (!*rebase_merges)
 993                         ; /* default mode; do nothing */
 994                 else if (!strcmp("rebase-cousins", rebase_merges))
 995                         options.rebase_cousins = 1;
 996                 else if (strcmp("no-rebase-cousins", rebase_merges))
 997                         die(_("Unknown mode: %s"), rebase_merges);
 998                 options.rebase_merges = 1;
 999                 imply_interactive(&options, "--rebase-merges");
1000         }
1001
1002         if (strategy_options.nr) {
1003                 int i;
1004
1005                 if (!options.strategy)
1006                         options.strategy = "recursive";
1007
1008                 strbuf_reset(&buf);
1009                 for (i = 0; i < strategy_options.nr; i++)
1010                         strbuf_addf(&buf, " --%s",
1011                                     strategy_options.items[i].string);
1012                 options.strategy_opts = xstrdup(buf.buf);
1013         }
1014
1015         if (options.strategy) {
1016                 options.strategy = xstrdup(options.strategy);
1017                 switch (options.type) {
1018                 case REBASE_AM:
1019                         die(_("--strategy requires --merge or --interactive"));
1020                 case REBASE_MERGE:
1021                 case REBASE_INTERACTIVE:
1022                 case REBASE_PRESERVE_MERGES:
1023                         /* compatible */
1024                         break;
1025                 case REBASE_UNSPECIFIED:
1026                         options.type = REBASE_MERGE;
1027                         break;
1028                 default:
1029                         BUG("unhandled rebase type (%d)", options.type);
1030                 }
1031         }
1032
1033         if (options.root && !options.onto_name)
1034                 imply_interactive(&options, "--root without --onto");
1035
1036         switch (options.type) {
1037         case REBASE_MERGE:
1038         case REBASE_INTERACTIVE:
1039         case REBASE_PRESERVE_MERGES:
1040                 options.state_dir = merge_dir();
1041                 break;
1042         case REBASE_AM:
1043                 options.state_dir = apply_dir();
1044                 break;
1045         default:
1046                 /* the default rebase backend is `--am` */
1047                 options.type = REBASE_AM;
1048                 options.state_dir = apply_dir();
1049                 break;
1050         }
1051
1052         if (options.signoff) {
1053                 if (options.type == REBASE_PRESERVE_MERGES)
1054                         die("cannot combine '--signoff' with "
1055                             "'--preserve-merges'");
1056                 strbuf_addstr(&options.git_am_opt, " --signoff");
1057                 options.flags |= REBASE_FORCE;
1058         }
1059
1060         if (!options.root) {
1061                 if (argc < 1)
1062                         die("TODO: handle @{upstream}");
1063                 else {
1064                         options.upstream_name = argv[0];
1065                         argc--;
1066                         argv++;
1067                         if (!strcmp(options.upstream_name, "-"))
1068                                 options.upstream_name = "@{-1}";
1069                 }
1070                 options.upstream = peel_committish(options.upstream_name);
1071                 if (!options.upstream)
1072                         die(_("invalid upstream '%s'"), options.upstream_name);
1073                 options.upstream_arg = options.upstream_name;
1074         } else {
1075                 if (!options.onto_name) {
1076                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1077                                         &squash_onto, NULL, NULL) < 0)
1078                                 die(_("Could not create new root commit"));
1079                         options.squash_onto = &squash_onto;
1080                         options.onto_name = squash_onto_name =
1081                                 xstrdup(oid_to_hex(&squash_onto));
1082                 }
1083                 options.upstream_name = NULL;
1084                 options.upstream = NULL;
1085                 if (argc > 1)
1086                         usage_with_options(builtin_rebase_usage,
1087                                            builtin_rebase_options);
1088                 options.upstream_arg = "--root";
1089         }
1090
1091         /* Make sure the branch to rebase onto is valid. */
1092         if (!options.onto_name)
1093                 options.onto_name = options.upstream_name;
1094         if (strstr(options.onto_name, "...")) {
1095                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
1096                         die(_("'%s': need exactly one merge base"),
1097                             options.onto_name);
1098                 options.onto = lookup_commit_or_die(&merge_base,
1099                                                     options.onto_name);
1100         } else {
1101                 options.onto = peel_committish(options.onto_name);
1102                 if (!options.onto)
1103                         die(_("Does not point to a valid commit '%s'"),
1104                                 options.onto_name);
1105         }
1106
1107         /*
1108          * If the branch to rebase is given, that is the branch we will rebase
1109          * branch_name -- branch/commit being rebased, or
1110          *                HEAD (already detached)
1111          * orig_head -- commit object name of tip of the branch before rebasing
1112          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1113          */
1114         if (argc == 1) {
1115                 /* Is it "rebase other branchname" or "rebase other commit"? */
1116                 branch_name = argv[0];
1117                 options.switch_to = argv[0];
1118
1119                 /* Is it a local branch? */
1120                 strbuf_reset(&buf);
1121                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1122                 if (!read_ref(buf.buf, &options.orig_head))
1123                         options.head_name = xstrdup(buf.buf);
1124                 /* If not is it a valid ref (branch or commit)? */
1125                 else if (!get_oid(branch_name, &options.orig_head))
1126                         options.head_name = NULL;
1127                 else
1128                         die(_("fatal: no such branch/commit '%s'"),
1129                             branch_name);
1130         } else if (argc == 0) {
1131                 /* Do not need to switch branches, we are already on it. */
1132                 options.head_name =
1133                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1134                                          &flags));
1135                 if (!options.head_name)
1136                         die(_("No such ref: %s"), "HEAD");
1137                 if (flags & REF_ISSYMREF) {
1138                         if (!skip_prefix(options.head_name,
1139                                          "refs/heads/", &branch_name))
1140                                 branch_name = options.head_name;
1141
1142                 } else {
1143                         free(options.head_name);
1144                         options.head_name = NULL;
1145                         branch_name = "HEAD";
1146                 }
1147                 if (get_oid("HEAD", &options.orig_head))
1148                         die(_("Could not resolve HEAD to a revision"));
1149         } else
1150                 BUG("unexpected number of arguments left to parse");
1151
1152         if (fork_point > 0) {
1153                 struct commit *head =
1154                         lookup_commit_reference(the_repository,
1155                                                 &options.orig_head);
1156                 options.restrict_revision =
1157                         get_fork_point(options.upstream_name, head);
1158         }
1159
1160         if (read_index(the_repository->index) < 0)
1161                 die(_("could not read index"));
1162
1163         if (options.autostash) {
1164                 struct lock_file lock_file = LOCK_INIT;
1165                 int fd;
1166
1167                 fd = hold_locked_index(&lock_file, 0);
1168                 refresh_cache(REFRESH_QUIET);
1169                 if (0 <= fd)
1170                         update_index_if_able(&the_index, &lock_file);
1171                 rollback_lock_file(&lock_file);
1172
1173                 if (has_unstaged_changes(0) || has_uncommitted_changes(0)) {
1174                         const char *autostash =
1175                                 state_dir_path("autostash", &options);
1176                         struct child_process stash = CHILD_PROCESS_INIT;
1177                         struct object_id oid;
1178                         struct commit *head =
1179                                 lookup_commit_reference(the_repository,
1180                                                         &options.orig_head);
1181
1182                         argv_array_pushl(&stash.args,
1183                                          "stash", "create", "autostash", NULL);
1184                         stash.git_cmd = 1;
1185                         stash.no_stdin = 1;
1186                         strbuf_reset(&buf);
1187                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1188                                 die(_("Cannot autostash"));
1189                         strbuf_trim_trailing_newline(&buf);
1190                         if (get_oid(buf.buf, &oid))
1191                                 die(_("Unexpected stash response: '%s'"),
1192                                     buf.buf);
1193                         strbuf_reset(&buf);
1194                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1195
1196                         if (safe_create_leading_directories_const(autostash))
1197                                 die(_("Could not create directory for '%s'"),
1198                                     options.state_dir);
1199                         write_file(autostash, "%s", buf.buf);
1200                         printf(_("Created autostash: %s\n"), buf.buf);
1201                         if (reset_head(&head->object.oid, "reset --hard",
1202                                        NULL, 0) < 0)
1203                                 die(_("could not reset --hard"));
1204                         printf(_("HEAD is now at %s"),
1205                                find_unique_abbrev(&head->object.oid,
1206                                                   DEFAULT_ABBREV));
1207                         strbuf_reset(&buf);
1208                         pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1209                         if (buf.len > 0)
1210                                 printf(" %s", buf.buf);
1211                         putchar('\n');
1212
1213                         if (discard_index(the_repository->index) < 0 ||
1214                                 read_index(the_repository->index) < 0)
1215                                 die(_("could not read index"));
1216                 }
1217         }
1218
1219         if (require_clean_work_tree("rebase",
1220                                     _("Please commit or stash them."), 1, 1)) {
1221                 ret = 1;
1222                 goto cleanup;
1223         }
1224
1225         /*
1226          * Now we are rebasing commits upstream..orig_head (or with --root,
1227          * everything leading up to orig_head) on top of onto.
1228          */
1229
1230         /*
1231          * Check if we are already based on onto with linear history,
1232          * but this should be done only when upstream and onto are the same
1233          * and if this is not an interactive rebase.
1234          */
1235         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1236             !is_interactive(&options) && !options.restrict_revision &&
1237             options.upstream &&
1238             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1239                 int flag;
1240
1241                 if (!(options.flags & REBASE_FORCE)) {
1242                         /* Lazily switch to the target branch if needed... */
1243                         if (options.switch_to) {
1244                                 struct object_id oid;
1245
1246                                 if (get_oid(options.switch_to, &oid) < 0) {
1247                                         ret = !!error(_("could not parse '%s'"),
1248                                                       options.switch_to);
1249                                         goto cleanup;
1250                                 }
1251
1252                                 strbuf_reset(&buf);
1253                                 strbuf_addf(&buf, "rebase: checkout %s",
1254                                             options.switch_to);
1255                                 if (reset_head(&oid, "checkout",
1256                                                options.head_name, 0) < 0) {
1257                                         ret = !!error(_("could not switch to "
1258                                                         "%s"),
1259                                                       options.switch_to);
1260                                         goto cleanup;
1261                                 }
1262                         }
1263
1264                         if (!(options.flags & REBASE_NO_QUIET))
1265                                 ; /* be quiet */
1266                         else if (!strcmp(branch_name, "HEAD") &&
1267                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1268                                 puts(_("HEAD is up to date."));
1269                         else
1270                                 printf(_("Current branch %s is up to date.\n"),
1271                                        branch_name);
1272                         ret = !!finish_rebase(&options);
1273                         goto cleanup;
1274                 } else if (!(options.flags & REBASE_NO_QUIET))
1275                         ; /* be quiet */
1276                 else if (!strcmp(branch_name, "HEAD") &&
1277                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1278                         puts(_("HEAD is up to date, rebase forced."));
1279                 else
1280                         printf(_("Current branch %s is up to date, rebase "
1281                                  "forced.\n"), branch_name);
1282         }
1283
1284         /* If a hook exists, give it a chance to interrupt*/
1285         if (!ok_to_skip_pre_rebase &&
1286             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1287                         argc ? argv[0] : NULL, NULL))
1288                 die(_("The pre-rebase hook refused to rebase."));
1289
1290         if (options.flags & REBASE_DIFFSTAT) {
1291                 struct diff_options opts;
1292
1293                 if (options.flags & REBASE_VERBOSE)
1294                         printf(_("Changes from %s to %s:\n"),
1295                                 oid_to_hex(&merge_base),
1296                                 oid_to_hex(&options.onto->object.oid));
1297
1298                 /* We want color (if set), but no pager */
1299                 diff_setup(&opts);
1300                 opts.stat_width = -1; /* use full terminal width */
1301                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1302                 opts.output_format |=
1303                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1304                 opts.detect_rename = DIFF_DETECT_RENAME;
1305                 diff_setup_done(&opts);
1306                 diff_tree_oid(&merge_base, &options.onto->object.oid,
1307                               "", &opts);
1308                 diffcore_std(&opts);
1309                 diff_flush(&opts);
1310         }
1311
1312         if (is_interactive(&options))
1313                 goto run_rebase;
1314
1315         /* Detach HEAD and reset the tree */
1316         if (options.flags & REBASE_NO_QUIET)
1317                 printf(_("First, rewinding head to replay your work on top of "
1318                          "it...\n"));
1319
1320         strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
1321         if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
1322                 die(_("Could not detach HEAD"));
1323         strbuf_release(&msg);
1324
1325         strbuf_addf(&revisions, "%s..%s",
1326                     options.root ? oid_to_hex(&options.onto->object.oid) :
1327                     (options.restrict_revision ?
1328                      oid_to_hex(&options.restrict_revision->object.oid) :
1329                      oid_to_hex(&options.upstream->object.oid)),
1330                     oid_to_hex(&options.orig_head));
1331
1332         options.revisions = revisions.buf;
1333
1334 run_rebase:
1335         ret = !!run_specific_rebase(&options);
1336
1337 cleanup:
1338         strbuf_release(&revisions);
1339         free(options.head_name);
1340         free(options.gpg_sign_opt);
1341         free(options.cmd);
1342         free(squash_onto_name);
1343         return ret;
1344 }