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