builtin/rebase.c

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   8 #include "builtin.h"
   9 #include "run-command.h"
  10 #include "exec-cmd.h"
  11 #include "argv-array.h"
  12 #include "dir.h"
  13 #include "packfile.h"
  14 #include "refs.h"
  15 #include "quote.h"
  16 #include "config.h"
  17 #include "cache-tree.h"
  18 #include "unpack-trees.h"
  19 #include "lockfile.h"
  20 #include "parse-options.h"
  21 #include "commit.h"
  22 #include "diff.h"
  23 #include "wt-status.h"
  24 #include "revision.h"
  25 #include "commit-reach.h"
  26 #include "rerere.h"
  27 #include "branch.h"
  28
  29 static char const * const builtin_rebase_usage[] = {
  30         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  31                 "[<upstream>] [<branch>]"),
  32         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  33                 "--root [<branch>]"),
  34         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  35         NULL
  36 };
  37
  38 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  39 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  40
  41 enum rebase_type {
  42         REBASE_UNSPECIFIED = -1,
  43         REBASE_AM,
  44         REBASE_MERGE,
  45         REBASE_INTERACTIVE,
  46         REBASE_PRESERVE_MERGES
  47 };
  48
  49 static int use_builtin_rebase(void)
  50 {
  51         struct child_process cp = CHILD_PROCESS_INIT;
  52         struct strbuf out = STRBUF_INIT;
  53         int ret, env = git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1);
  54
  55         if (env != -1)
  56                 return env;
  57
  58         argv_array_pushl(&cp.args,
  59                          "config", "--bool", "rebase.usebuiltin", NULL);
  60         cp.git_cmd = 1;
  61         if (capture_command(&cp, &out, 6)) {
  62                 strbuf_release(&out);
  63                 return 1;
  64         }
  65
  66         strbuf_trim(&out);
  67         ret = !strcmp("true", out.buf);
  68         strbuf_release(&out);
  69         return ret;
  70 }
  71
  72 struct rebase_options {
  73         enum rebase_type type;
  74         const char *state_dir;
  75         struct commit *upstream;
  76         const char *upstream_name;
  77         const char *upstream_arg;
  78         char *head_name;
  79         struct object_id orig_head;
  80         struct commit *onto;
  81         const char *onto_name;
  82         const char *revisions;
  83         const char *switch_to;
  84         int root;
  85         struct object_id *squash_onto;
  86         struct commit *restrict_revision;
  87         int dont_finish_rebase;
  88         enum {
  89                 REBASE_NO_QUIET = 1<<0,
  90                 REBASE_VERBOSE = 1<<1,
  91                 REBASE_DIFFSTAT = 1<<2,
  92                 REBASE_FORCE = 1<<3,
  93                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  94         } flags;
  95         struct argv_array git_am_opts;
  96         const char *action;
  97         int signoff;
  98         int allow_rerere_autoupdate;
  99         int keep_empty;
 100         int autosquash;
 101         char *gpg_sign_opt;
 102         int autostash;
 103         char *cmd;
 104         int allow_empty_message;
 105         int rebase_merges, rebase_cousins;
 106         char *strategy, *strategy_opts;
 107         struct strbuf git_format_patch_opt;
 108         int reschedule_failed_exec;
 109 };
 110
 111 static int is_interactive(struct rebase_options *opts)
 112 {
 113         return opts->type == REBASE_INTERACTIVE ||
 114                 opts->type == REBASE_PRESERVE_MERGES;
 115 }
 116
 117 static void imply_interactive(struct rebase_options *opts, const char *option)
 118 {
 119         switch (opts->type) {
 120         case REBASE_AM:
 121                 die(_("%s requires an interactive rebase"), option);
 122                 break;
 123         case REBASE_INTERACTIVE:
 124         case REBASE_PRESERVE_MERGES:
 125                 break;
 126         case REBASE_MERGE:
 127                 /* we now implement --merge via --interactive */
 128         default:
 129                 opts->type = REBASE_INTERACTIVE; /* implied */
 130                 break;
 131         }
 132 }
 133
 134 /* Returns the filename prefixed by the state_dir */
 135 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 136 {
 137         static struct strbuf path = STRBUF_INIT;
 138         static size_t prefix_len;
 139
 140         if (!prefix_len) {
 141                 strbuf_addf(&path, "%s/", opts->state_dir);
 142                 prefix_len = path.len;
 143         }
 144
 145         strbuf_setlen(&path, prefix_len);
 146         strbuf_addstr(&path, filename);
 147         return path.buf;
 148 }
 149
 150 /* Read one file, then strip line endings */
 151 static int read_one(const char *path, struct strbuf *buf)
 152 {
 153         if (strbuf_read_file(buf, path, 0) < 0)
 154                 return error_errno(_("could not read '%s'"), path);
 155         strbuf_trim_trailing_newline(buf);
 156         return 0;
 157 }
 158
 159 /* Initialize the rebase options from the state directory. */
 160 static int read_basic_state(struct rebase_options *opts)
 161 {
 162         struct strbuf head_name = STRBUF_INIT;
 163         struct strbuf buf = STRBUF_INIT;
 164         struct object_id oid;
 165
 166         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 167             read_one(state_dir_path("onto", opts), &buf))
 168                 return -1;
 169         opts->head_name = starts_with(head_name.buf, "refs/") ?
 170                 xstrdup(head_name.buf) : NULL;
 171         strbuf_release(&head_name);
 172         if (get_oid(buf.buf, &oid))
 173                 return error(_("could not get 'onto': '%s'"), buf.buf);
 174         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 175
 176         /*
 177          * We always write to orig-head, but interactive rebase used to write to
 178          * head. Fall back to reading from head to cover for the case that the
 179          * user upgraded git with an ongoing interactive rebase.
 180          */
 181         strbuf_reset(&buf);
 182         if (file_exists(state_dir_path("orig-head", opts))) {
 183                 if (read_one(state_dir_path("orig-head", opts), &buf))
 184                         return -1;
 185         } else if (read_one(state_dir_path("head", opts), &buf))
 186                 return -1;
 187         if (get_oid(buf.buf, &opts->orig_head))
 188                 return error(_("invalid orig-head: '%s'"), buf.buf);
 189
 190         if (file_exists(state_dir_path("quiet", opts)))
 191                 opts->flags &= ~REBASE_NO_QUIET;
 192         else
 193                 opts->flags |= REBASE_NO_QUIET;
 194
 195         if (file_exists(state_dir_path("verbose", opts)))
 196                 opts->flags |= REBASE_VERBOSE;
 197
 198         if (file_exists(state_dir_path("signoff", opts))) {
 199                 opts->signoff = 1;
 200                 opts->flags |= REBASE_FORCE;
 201         }
 202
 203         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 204                 strbuf_reset(&buf);
 205                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 206                             &buf))
 207                         return -1;
 208                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 209                         opts->allow_rerere_autoupdate = 1;
 210                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 211                         opts->allow_rerere_autoupdate = 0;
 212                 else
 213                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 214                                   "'%s'"), buf.buf);
 215         } else
 216                 opts->allow_rerere_autoupdate = -1;
 217
 218         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 219                 strbuf_reset(&buf);
 220                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 221                             &buf))
 222                         return -1;
 223                 free(opts->gpg_sign_opt);
 224                 opts->gpg_sign_opt = xstrdup(buf.buf);
 225         }
 226
 227         if (file_exists(state_dir_path("strategy", opts))) {
 228                 strbuf_reset(&buf);
 229                 if (read_one(state_dir_path("strategy", opts), &buf))
 230                         return -1;
 231                 free(opts->strategy);
 232                 opts->strategy = xstrdup(buf.buf);
 233         }
 234
 235         if (file_exists(state_dir_path("strategy_opts", opts))) {
 236                 strbuf_reset(&buf);
 237                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 238                         return -1;
 239                 free(opts->strategy_opts);
 240                 opts->strategy_opts = xstrdup(buf.buf);
 241         }
 242
 243         strbuf_release(&buf);
 244
 245         return 0;
 246 }
 247
 248 static int write_basic_state(struct rebase_options *opts)
 249 {
 250         write_file(state_dir_path("head-name", opts), "%s",
 251                    opts->head_name ? opts->head_name : "detached HEAD");
 252         write_file(state_dir_path("onto", opts), "%s",
 253                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 254         write_file(state_dir_path("orig-head", opts), "%s",
 255                    oid_to_hex(&opts->orig_head));
 256         write_file(state_dir_path("quiet", opts), "%s",
 257                    opts->flags & REBASE_NO_QUIET ? "" : "t");
 258         if (opts->flags & REBASE_VERBOSE)
 259                 write_file(state_dir_path("verbose", opts), "%s", "");
 260         if (opts->strategy)
 261                 write_file(state_dir_path("strategy", opts), "%s",
 262                            opts->strategy);
 263         if (opts->strategy_opts)
 264                 write_file(state_dir_path("strategy_opts", opts), "%s",
 265                            opts->strategy_opts);
 266         if (opts->allow_rerere_autoupdate >= 0)
 267                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 268                            "-%s-rerere-autoupdate",
 269                            opts->allow_rerere_autoupdate ? "" : "-no");
 270         if (opts->gpg_sign_opt)
 271                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 272                            opts->gpg_sign_opt);
 273         if (opts->signoff)
 274                 write_file(state_dir_path("strategy", opts), "--signoff");
 275
 276         return 0;
 277 }
 278
 279 static int apply_autostash(struct rebase_options *opts)
 280 {
 281         const char *path = state_dir_path("autostash", opts);
 282         struct strbuf autostash = STRBUF_INIT;
 283         struct child_process stash_apply = CHILD_PROCESS_INIT;
 284
 285         if (!file_exists(path))
 286                 return 0;
 287
 288         if (read_one(path, &autostash))
 289                 return error(_("Could not read '%s'"), path);
 290         /* Ensure that the hash is not mistaken for a number */
 291         strbuf_addstr(&autostash, "^0");
 292         argv_array_pushl(&stash_apply.args,
 293                          "stash", "apply", autostash.buf, NULL);
 294         stash_apply.git_cmd = 1;
 295         stash_apply.no_stderr = stash_apply.no_stdout =
 296                 stash_apply.no_stdin = 1;
 297         if (!run_command(&stash_apply))
 298                 printf(_("Applied autostash.\n"));
 299         else {
 300                 struct argv_array args = ARGV_ARRAY_INIT;
 301                 int res = 0;
 302
 303                 argv_array_pushl(&args,
 304                                  "stash", "store", "-m", "autostash", "-q",
 305                                  autostash.buf, NULL);
 306                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 307                         res = error(_("Cannot store %s"), autostash.buf);
 308                 argv_array_clear(&args);
 309                 strbuf_release(&autostash);
 310                 if (res)
 311                         return res;
 312
 313                 fprintf(stderr,
 314                         _("Applying autostash resulted in conflicts.\n"
 315                           "Your changes are safe in the stash.\n"
 316                           "You can run \"git stash pop\" or \"git stash drop\" "
 317                           "at any time.\n"));
 318         }
 319
 320         strbuf_release(&autostash);
 321         return 0;
 322 }
 323
 324 static int finish_rebase(struct rebase_options *opts)
 325 {
 326         struct strbuf dir = STRBUF_INIT;
 327         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 328
 329         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 330         apply_autostash(opts);
 331         close_all_packs(the_repository->objects);
 332         /*
 333          * We ignore errors in 'gc --auto', since the
 334          * user should see them.
 335          */
 336         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 337         strbuf_addstr(&dir, opts->state_dir);
 338         remove_dir_recursively(&dir, 0);
 339         strbuf_release(&dir);
 340
 341         return 0;
 342 }
 343
 344 static struct commit *peel_committish(const char *name)
 345 {
 346         struct object *obj;
 347         struct object_id oid;
 348
 349         if (get_oid(name, &oid))
 350                 return NULL;
 351         obj = parse_object(the_repository, &oid);
 352         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 353 }
 354
 355 static void add_var(struct strbuf *buf, const char *name, const char *value)
 356 {
 357         if (!value)
 358                 strbuf_addf(buf, "unset %s; ", name);
 359         else {
 360                 strbuf_addf(buf, "%s=", name);
 361                 sq_quote_buf(buf, value);
 362                 strbuf_addstr(buf, "; ");
 363         }
 364 }
 365
 366 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 367
 368 #define RESET_HEAD_DETACH (1<<0)
 369 #define RESET_HEAD_HARD (1<<1)
 370 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 371 #define RESET_HEAD_REFS_ONLY (1<<3)
 372 #define RESET_ORIG_HEAD (1<<4)
 373
 374 static int reset_head(struct object_id *oid, const char *action,
 375                       const char *switch_to_branch, unsigned flags,
 376                       const char *reflog_orig_head, const char *reflog_head)
 377 {
 378         unsigned detach_head = flags & RESET_HEAD_DETACH;
 379         unsigned reset_hard = flags & RESET_HEAD_HARD;
 380         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 381         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 382         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 383         struct object_id head_oid;
 384         struct tree_desc desc[2] = { { NULL }, { NULL } };
 385         struct lock_file lock = LOCK_INIT;
 386         struct unpack_trees_options unpack_tree_opts;
 387         struct tree *tree;
 388         const char *reflog_action;
 389         struct strbuf msg = STRBUF_INIT;
 390         size_t prefix_len;
 391         struct object_id *orig = NULL, oid_orig,
 392                 *old_orig = NULL, oid_old_orig;
 393         int ret = 0, nr = 0;
 394
 395         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 396                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 397
 398         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 399                 ret = -1;
 400                 goto leave_reset_head;
 401         }
 402
 403         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 404                 ret = error(_("could not determine HEAD revision"));
 405                 goto leave_reset_head;
 406         }
 407
 408         if (!oid)
 409                 oid = &head_oid;
 410
 411         if (refs_only)
 412                 goto reset_head_refs;
 413
 414         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 415         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 416         unpack_tree_opts.head_idx = 1;
 417         unpack_tree_opts.src_index = the_repository->index;
 418         unpack_tree_opts.dst_index = the_repository->index;
 419         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 420         unpack_tree_opts.update = 1;
 421         unpack_tree_opts.merge = 1;
 422         if (!detach_head)
 423                 unpack_tree_opts.reset = 1;
 424
 425         if (repo_read_index_unmerged(the_repository) < 0) {
 426                 ret = error(_("could not read index"));
 427                 goto leave_reset_head;
 428         }
 429
 430         if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
 431                 ret = error(_("failed to find tree of %s"),
 432                             oid_to_hex(&head_oid));
 433                 goto leave_reset_head;
 434         }
 435
 436         if (!fill_tree_descriptor(&desc[nr++], oid)) {
 437                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 438                 goto leave_reset_head;
 439         }
 440
 441         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 442                 ret = -1;
 443                 goto leave_reset_head;
 444         }
 445
 446         tree = parse_tree_indirect(oid);
 447         prime_cache_tree(the_repository, the_repository->index, tree);
 448
 449         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 450                 ret = error(_("could not write index"));
 451                 goto leave_reset_head;
 452         }
 453
 454 reset_head_refs:
 455         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 456         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 457         prefix_len = msg.len;
 458
 459         if (update_orig_head) {
 460                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 461                         old_orig = &oid_old_orig;
 462                 if (!get_oid("HEAD", &oid_orig)) {
 463                         orig = &oid_orig;
 464                         if (!reflog_orig_head) {
 465                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 466                                 reflog_orig_head = msg.buf;
 467                         }
 468                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 469                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 470                 } else if (old_orig)
 471                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 472         }
 473
 474         if (!reflog_head) {
 475                 strbuf_setlen(&msg, prefix_len);
 476                 strbuf_addstr(&msg, "updating HEAD");
 477                 reflog_head = msg.buf;
 478         }
 479         if (!switch_to_branch)
 480                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 481                                  detach_head ? REF_NO_DEREF : 0,
 482                                  UPDATE_REFS_MSG_ON_ERR);
 483         else {
 484                 ret = update_ref(reflog_head, switch_to_branch, oid,
 485                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 486                 if (!ret)
 487                         ret = create_symref("HEAD", switch_to_branch,
 488                                             reflog_head);
 489         }
 490         if (run_hook)
 491                 run_hook_le(NULL, "post-checkout",
 492                             oid_to_hex(orig ? orig : &null_oid),
 493                             oid_to_hex(oid), "1", NULL);
 494
 495 leave_reset_head:
 496         strbuf_release(&msg);
 497         rollback_lock_file(&lock);
 498         while (nr)
 499                 free((void *)desc[--nr].buffer);
 500         return ret;
 501 }
 502
 503 static int move_to_original_branch(struct rebase_options *opts)
 504 {
 505         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 506         int ret;
 507
 508         if (!opts->head_name)
 509                 return 0; /* nothing to move back to */
 510
 511         if (!opts->onto)
 512                 BUG("move_to_original_branch without onto");
 513
 514         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 515                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 516         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 517                     opts->head_name);
 518         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 519                          orig_head_reflog.buf, head_reflog.buf);
 520
 521         strbuf_release(&orig_head_reflog);
 522         strbuf_release(&head_reflog);
 523         return ret;
 524 }
 525
 526 static const char *resolvemsg =
 527 N_("Resolve all conflicts manually, mark them as resolved with\n"
 528 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 529 "You can instead skip this commit: run \"git rebase --skip\".\n"
 530 "To abort and get back to the state before \"git rebase\", run "
 531 "\"git rebase --abort\".");
 532
 533 static int run_am(struct rebase_options *opts)
 534 {
 535         struct child_process am = CHILD_PROCESS_INIT;
 536         struct child_process format_patch = CHILD_PROCESS_INIT;
 537         struct strbuf revisions = STRBUF_INIT;
 538         int status;
 539         char *rebased_patches;
 540
 541         am.git_cmd = 1;
 542         argv_array_push(&am.args, "am");
 543
 544         if (opts->action && !strcmp("continue", opts->action)) {
 545                 argv_array_push(&am.args, "--resolved");
 546                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 547                 if (opts->gpg_sign_opt)
 548                         argv_array_push(&am.args, opts->gpg_sign_opt);
 549                 status = run_command(&am);
 550                 if (status)
 551                         return status;
 552
 553                 return move_to_original_branch(opts);
 554         }
 555         if (opts->action && !strcmp("skip", opts->action)) {
 556                 argv_array_push(&am.args, "--skip");
 557                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 558                 status = run_command(&am);
 559                 if (status)
 560                         return status;
 561
 562                 return move_to_original_branch(opts);
 563         }
 564         if (opts->action && !strcmp("show-current-patch", opts->action)) {
 565                 argv_array_push(&am.args, "--show-current-patch");
 566                 return run_command(&am);
 567         }
 568
 569         strbuf_addf(&revisions, "%s...%s",
 570                     oid_to_hex(opts->root ?
 571                                /* this is now equivalent to !opts->upstream */
 572                                &opts->onto->object.oid :
 573                                &opts->upstream->object.oid),
 574                     oid_to_hex(&opts->orig_head));
 575
 576         rebased_patches = xstrdup(git_path("rebased-patches"));
 577         format_patch.out = open(rebased_patches,
 578                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
 579         if (format_patch.out < 0) {
 580                 status = error_errno(_("could not open '%s' for writing"),
 581                                      rebased_patches);
 582                 free(rebased_patches);
 583                 argv_array_clear(&am.args);
 584                 return status;
 585         }
 586
 587         format_patch.git_cmd = 1;
 588         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
 589                          "--full-index", "--cherry-pick", "--right-only",
 590                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
 591                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
 592         if (opts->git_format_patch_opt.len)
 593                 argv_array_split(&format_patch.args,
 594                                  opts->git_format_patch_opt.buf);
 595         argv_array_push(&format_patch.args, revisions.buf);
 596         if (opts->restrict_revision)
 597                 argv_array_pushf(&format_patch.args, "^%s",
 598                                  oid_to_hex(&opts->restrict_revision->object.oid));
 599
 600         status = run_command(&format_patch);
 601         if (status) {
 602                 unlink(rebased_patches);
 603                 free(rebased_patches);
 604                 argv_array_clear(&am.args);
 605
 606                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
 607                            "HEAD", NULL);
 608                 error(_("\ngit encountered an error while preparing the "
 609                         "patches to replay\n"
 610                         "these revisions:\n"
 611                         "\n    %s\n\n"
 612                         "As a result, git cannot rebase them."),
 613                       opts->revisions);
 614
 615                 strbuf_release(&revisions);
 616                 return status;
 617         }
 618         strbuf_release(&revisions);
 619
 620         am.in = open(rebased_patches, O_RDONLY);
 621         if (am.in < 0) {
 622                 status = error_errno(_("could not open '%s' for reading"),
 623                                      rebased_patches);
 624                 free(rebased_patches);
 625                 argv_array_clear(&am.args);
 626                 return status;
 627         }
 628
 629         argv_array_pushv(&am.args, opts->git_am_opts.argv);
 630         argv_array_push(&am.args, "--rebasing");
 631         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 632         argv_array_push(&am.args, "--patch-format=mboxrd");
 633         if (opts->allow_rerere_autoupdate > 0)
 634                 argv_array_push(&am.args, "--rerere-autoupdate");
 635         else if (opts->allow_rerere_autoupdate == 0)
 636                 argv_array_push(&am.args, "--no-rerere-autoupdate");
 637         if (opts->gpg_sign_opt)
 638                 argv_array_push(&am.args, opts->gpg_sign_opt);
 639         status = run_command(&am);
 640         unlink(rebased_patches);
 641         free(rebased_patches);
 642
 643         if (!status) {
 644                 return move_to_original_branch(opts);
 645         }
 646
 647         if (is_directory(opts->state_dir))
 648                 write_basic_state(opts);
 649
 650         return status;
 651 }
 652
 653 static int run_specific_rebase(struct rebase_options *opts)
 654 {
 655         const char *argv[] = { NULL, NULL };
 656         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
 657         int status;
 658         const char *backend, *backend_func;
 659
 660         if (opts->type == REBASE_INTERACTIVE) {
 661                 /* Run builtin interactive rebase */
 662                 struct child_process child = CHILD_PROCESS_INIT;
 663
 664                 argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 665                                  resolvemsg);
 666                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 667                         argv_array_push(&child.env_array,
 668                                         "GIT_SEQUENCE_EDITOR=:");
 669                         opts->autosquash = 0;
 670                 }
 671
 672                 child.git_cmd = 1;
 673                 argv_array_push(&child.args, "rebase--interactive");
 674
 675                 if (opts->action)
 676                         argv_array_pushf(&child.args, "--%s", opts->action);
 677                 if (opts->keep_empty)
 678                         argv_array_push(&child.args, "--keep-empty");
 679                 if (opts->rebase_merges)
 680                         argv_array_push(&child.args, "--rebase-merges");
 681                 if (opts->rebase_cousins)
 682                         argv_array_push(&child.args, "--rebase-cousins");
 683                 if (opts->autosquash)
 684                         argv_array_push(&child.args, "--autosquash");
 685                 if (opts->flags & REBASE_VERBOSE)
 686                         argv_array_push(&child.args, "--verbose");
 687                 if (opts->flags & REBASE_FORCE)
 688                         argv_array_push(&child.args, "--no-ff");
 689                 if (opts->restrict_revision)
 690                         argv_array_pushf(&child.args,
 691                                          "--restrict-revision=^%s",
 692                                          oid_to_hex(&opts->restrict_revision->object.oid));
 693                 if (opts->upstream)
 694                         argv_array_pushf(&child.args, "--upstream=%s",
 695                                          oid_to_hex(&opts->upstream->object.oid));
 696                 if (opts->onto)
 697                         argv_array_pushf(&child.args, "--onto=%s",
 698                                          oid_to_hex(&opts->onto->object.oid));
 699                 if (opts->squash_onto)
 700                         argv_array_pushf(&child.args, "--squash-onto=%s",
 701                                          oid_to_hex(opts->squash_onto));
 702                 if (opts->onto_name)
 703                         argv_array_pushf(&child.args, "--onto-name=%s",
 704                                          opts->onto_name);
 705                 argv_array_pushf(&child.args, "--head-name=%s",
 706                                  opts->head_name ?
 707                                  opts->head_name : "detached HEAD");
 708                 if (opts->strategy)
 709                         argv_array_pushf(&child.args, "--strategy=%s",
 710                                          opts->strategy);
 711                 if (opts->strategy_opts)
 712                         argv_array_pushf(&child.args, "--strategy-opts=%s",
 713                                          opts->strategy_opts);
 714                 if (opts->switch_to)
 715                         argv_array_pushf(&child.args, "--switch-to=%s",
 716                                          opts->switch_to);
 717                 if (opts->cmd)
 718                         argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
 719                 if (opts->allow_empty_message)
 720                         argv_array_push(&child.args, "--allow-empty-message");
 721                 if (opts->allow_rerere_autoupdate > 0)
 722                         argv_array_push(&child.args, "--rerere-autoupdate");
 723                 else if (opts->allow_rerere_autoupdate == 0)
 724                         argv_array_push(&child.args, "--no-rerere-autoupdate");
 725                 if (opts->gpg_sign_opt)
 726                         argv_array_push(&child.args, opts->gpg_sign_opt);
 727                 if (opts->signoff)
 728                         argv_array_push(&child.args, "--signoff");
 729                 if (opts->reschedule_failed_exec)
 730                         argv_array_push(&child.args, "--reschedule-failed-exec");
 731
 732                 status = run_command(&child);
 733                 goto finished_rebase;
 734         }
 735
 736         if (opts->type == REBASE_AM) {
 737                 status = run_am(opts);
 738                 goto finished_rebase;
 739         }
 740
 741         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 742         add_var(&script_snippet, "state_dir", opts->state_dir);
 743
 744         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 745         add_var(&script_snippet, "upstream", opts->upstream ?
 746                 oid_to_hex(&opts->upstream->object.oid) : NULL);
 747         add_var(&script_snippet, "head_name",
 748                 opts->head_name ? opts->head_name : "detached HEAD");
 749         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 750         add_var(&script_snippet, "onto", opts->onto ?
 751                 oid_to_hex(&opts->onto->object.oid) : NULL);
 752         add_var(&script_snippet, "onto_name", opts->onto_name);
 753         add_var(&script_snippet, "revisions", opts->revisions);
 754         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 755                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 756         add_var(&script_snippet, "GIT_QUIET",
 757                 opts->flags & REBASE_NO_QUIET ? "" : "t");
 758         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
 759         add_var(&script_snippet, "git_am_opt", buf.buf);
 760         strbuf_release(&buf);
 761         add_var(&script_snippet, "verbose",
 762                 opts->flags & REBASE_VERBOSE ? "t" : "");
 763         add_var(&script_snippet, "diffstat",
 764                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
 765         add_var(&script_snippet, "force_rebase",
 766                 opts->flags & REBASE_FORCE ? "t" : "");
 767         if (opts->switch_to)
 768                 add_var(&script_snippet, "switch_to", opts->switch_to);
 769         add_var(&script_snippet, "action", opts->action ? opts->action : "");
 770         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 771         add_var(&script_snippet, "allow_rerere_autoupdate",
 772                 opts->allow_rerere_autoupdate < 0 ? "" :
 773                 opts->allow_rerere_autoupdate ?
 774                 "--rerere-autoupdate" : "--no-rerere-autoupdate");
 775         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 776         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 777         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 778         add_var(&script_snippet, "cmd", opts->cmd);
 779         add_var(&script_snippet, "allow_empty_message",
 780                 opts->allow_empty_message ?  "--allow-empty-message" : "");
 781         add_var(&script_snippet, "rebase_merges",
 782                 opts->rebase_merges ? "t" : "");
 783         add_var(&script_snippet, "rebase_cousins",
 784                 opts->rebase_cousins ? "t" : "");
 785         add_var(&script_snippet, "strategy", opts->strategy);
 786         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 787         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 788         add_var(&script_snippet, "squash_onto",
 789                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 790         add_var(&script_snippet, "git_format_patch_opt",
 791                 opts->git_format_patch_opt.buf);
 792
 793         if (is_interactive(opts) &&
 794             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 795                 strbuf_addstr(&script_snippet,
 796                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
 797                 opts->autosquash = 0;
 798         }
 799
 800         switch (opts->type) {
 801         case REBASE_AM:
 802                 backend = "git-rebase--am";
 803                 backend_func = "git_rebase__am";
 804                 break;
 805         case REBASE_PRESERVE_MERGES:
 806                 backend = "git-rebase--preserve-merges";
 807                 backend_func = "git_rebase__preserve_merges";
 808                 break;
 809         default:
 810                 BUG("Unhandled rebase type %d", opts->type);
 811                 break;
 812         }
 813
 814         strbuf_addf(&script_snippet,
 815                     ". git-sh-setup && . git-rebase--common &&"
 816                     " . %s && %s", backend, backend_func);
 817         argv[0] = script_snippet.buf;
 818
 819         status = run_command_v_opt(argv, RUN_USING_SHELL);
 820 finished_rebase:
 821         if (opts->dont_finish_rebase)
 822                 ; /* do nothing */
 823         else if (opts->type == REBASE_INTERACTIVE)
 824                 ; /* interactive rebase cleans up after itself */
 825         else if (status == 0) {
 826                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 827                         finish_rebase(opts);
 828         } else if (status == 2) {
 829                 struct strbuf dir = STRBUF_INIT;
 830
 831                 apply_autostash(opts);
 832                 strbuf_addstr(&dir, opts->state_dir);
 833                 remove_dir_recursively(&dir, 0);
 834                 strbuf_release(&dir);
 835                 die("Nothing to do");
 836         }
 837
 838         strbuf_release(&script_snippet);
 839
 840         return status ? -1 : 0;
 841 }
 842
 843 static int rebase_config(const char *var, const char *value, void *data)
 844 {
 845         struct rebase_options *opts = data;
 846
 847         if (!strcmp(var, "rebase.stat")) {
 848                 if (git_config_bool(var, value))
 849                         opts->flags |= REBASE_DIFFSTAT;
 850                 else
 851                         opts->flags &= !REBASE_DIFFSTAT;
 852                 return 0;
 853         }
 854
 855         if (!strcmp(var, "rebase.autosquash")) {
 856                 opts->autosquash = git_config_bool(var, value);
 857                 return 0;
 858         }
 859
 860         if (!strcmp(var, "commit.gpgsign")) {
 861                 free(opts->gpg_sign_opt);
 862                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 863                         xstrdup("-S") : NULL;
 864                 return 0;
 865         }
 866
 867         if (!strcmp(var, "rebase.autostash")) {
 868                 opts->autostash = git_config_bool(var, value);
 869                 return 0;
 870         }
 871
 872         if (!strcmp(var, "rebase.reschedulefailedexec")) {
 873                 opts->reschedule_failed_exec = git_config_bool(var, value);
 874                 return 0;
 875         }
 876
 877         return git_default_config(var, value, data);
 878 }
 879
 880 /*
 881  * Determines whether the commits in from..to are linear, i.e. contain
 882  * no merge commits. This function *expects* `from` to be an ancestor of
 883  * `to`.
 884  */
 885 static int is_linear_history(struct commit *from, struct commit *to)
 886 {
 887         while (to && to != from) {
 888                 parse_commit(to);
 889                 if (!to->parents)
 890                         return 1;
 891                 if (to->parents->next)
 892                         return 0;
 893                 to = to->parents->item;
 894         }
 895         return 1;
 896 }
 897
 898 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 899                             struct object_id *merge_base)
 900 {
 901         struct commit *head = lookup_commit(the_repository, head_oid);
 902         struct commit_list *merge_bases;
 903         int res;
 904
 905         if (!head)
 906                 return 0;
 907
 908         merge_bases = get_merge_bases(onto, head);
 909         if (merge_bases && !merge_bases->next) {
 910                 oidcpy(merge_base, &merge_bases->item->object.oid);
 911                 res = oideq(merge_base, &onto->object.oid);
 912         } else {
 913                 oidcpy(merge_base, &null_oid);
 914                 res = 0;
 915         }
 916         free_commit_list(merge_bases);
 917         return res && is_linear_history(onto, head);
 918 }
 919
 920 /* -i followed by -m is still -i */
 921 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 922 {
 923         struct rebase_options *opts = opt->value;
 924
 925         BUG_ON_OPT_NEG(unset);
 926         BUG_ON_OPT_ARG(arg);
 927
 928         if (!is_interactive(opts))
 929                 opts->type = REBASE_MERGE;
 930
 931         return 0;
 932 }
 933
 934 /* -i followed by -p is still explicitly interactive, but -p alone is not */
 935 static int parse_opt_interactive(const struct option *opt, const char *arg,
 936                                  int unset)
 937 {
 938         struct rebase_options *opts = opt->value;
 939
 940         BUG_ON_OPT_NEG(unset);
 941         BUG_ON_OPT_ARG(arg);
 942
 943         opts->type = REBASE_INTERACTIVE;
 944         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 945
 946         return 0;
 947 }
 948
 949 static void NORETURN error_on_missing_default_upstream(void)
 950 {
 951         struct branch *current_branch = branch_get(NULL);
 952
 953         printf(_("%s\n"
 954                  "Please specify which branch you want to rebase against.\n"
 955                  "See git-rebase(1) for details.\n"
 956                  "\n"
 957                  "    git rebase '<branch>'\n"
 958                  "\n"),
 959                 current_branch ? _("There is no tracking information for "
 960                         "the current branch.") :
 961                         _("You are not currently on a branch."));
 962
 963         if (current_branch) {
 964                 const char *remote = current_branch->remote_name;
 965
 966                 if (!remote)
 967                         remote = _("<remote>");
 968
 969                 printf(_("If you wish to set tracking information for this "
 970                          "branch you can do so with:\n"
 971                          "\n"
 972                          "    git branch --set-upstream-to=%s/<branch> %s\n"
 973                          "\n"),
 974                        remote, current_branch->name);
 975         }
 976         exit(1);
 977 }
 978
 979 static void set_reflog_action(struct rebase_options *options)
 980 {
 981         const char *env;
 982         struct strbuf buf = STRBUF_INIT;
 983
 984         if (!is_interactive(options))
 985                 return;
 986
 987         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 988         if (env && strcmp("rebase", env))
 989                 return; /* only override it if it is "rebase" */
 990
 991         strbuf_addf(&buf, "rebase -i (%s)", options->action);
 992         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
 993         strbuf_release(&buf);
 994 }
 995
 996 static int check_exec_cmd(const char *cmd)
 997 {
 998         if (strchr(cmd, '\n'))
 999                 return error(_("exec commands cannot contain newlines"));
1000
1001         /* Does the command consist purely of whitespace? */
1002         if (!cmd[strspn(cmd, " \t\r\f\v")])
1003                 return error(_("empty exec command"));
1004
1005         return 0;
1006 }
1007
1008
1009 int cmd_rebase(int argc, const char **argv, const char *prefix)
1010 {
1011         struct rebase_options options = {
1012                 .type = REBASE_UNSPECIFIED,
1013                 .flags = REBASE_NO_QUIET,
1014                 .git_am_opts = ARGV_ARRAY_INIT,
1015                 .allow_rerere_autoupdate  = -1,
1016                 .allow_empty_message = 1,
1017                 .git_format_patch_opt = STRBUF_INIT,
1018         };
1019         const char *branch_name;
1020         int ret, flags, total_argc, in_progress = 0;
1021         int ok_to_skip_pre_rebase = 0;
1022         struct strbuf msg = STRBUF_INIT;
1023         struct strbuf revisions = STRBUF_INIT;
1024         struct strbuf buf = STRBUF_INIT;
1025         struct object_id merge_base;
1026         enum {
1027                 NO_ACTION,
1028                 ACTION_CONTINUE,
1029                 ACTION_SKIP,
1030                 ACTION_ABORT,
1031                 ACTION_QUIT,
1032                 ACTION_EDIT_TODO,
1033                 ACTION_SHOW_CURRENT_PATCH,
1034         } action = NO_ACTION;
1035         static const char *action_names[] = { N_("undefined"),
1036                                               N_("continue"),
1037                                               N_("skip"),
1038                                               N_("abort"),
1039                                               N_("quit"),
1040                                               N_("edit_todo"),
1041                                               N_("show_current_patch"),
1042                                               NULL };
1043         const char *gpg_sign = NULL;
1044         struct string_list exec = STRING_LIST_INIT_NODUP;
1045         const char *rebase_merges = NULL;
1046         int fork_point = -1;
1047         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1048         struct object_id squash_onto;
1049         char *squash_onto_name = NULL;
1050         struct option builtin_rebase_options[] = {
1051                 OPT_STRING(0, "onto", &options.onto_name,
1052                            N_("revision"),
1053                            N_("rebase onto given branch instead of upstream")),
1054                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1055                          N_("allow pre-rebase hook to run")),
1056                 OPT_NEGBIT('q', "quiet", &options.flags,
1057                            N_("be quiet. implies --no-stat"),
1058                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1059                 OPT_BIT('v', "verbose", &options.flags,
1060                         N_("display a diffstat of what changed upstream"),
1061                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1062                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1063                         N_("do not show diffstat of what changed upstream"),
1064                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1065                 OPT_BOOL(0, "signoff", &options.signoff,
1066                          N_("add a Signed-off-by: line to each commit")),
1067                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1068                                   NULL, N_("passed to 'git am'"),
1069                                   PARSE_OPT_NOARG),
1070                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1071                                   &options.git_am_opts, NULL,
1072                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1073                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1074                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1075                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1076                                   N_("passed to 'git apply'"), 0),
1077                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1078                                   N_("action"), N_("passed to 'git apply'"), 0),
1079                 OPT_BIT('f', "force-rebase", &options.flags,
1080                         N_("cherry-pick all commits, even if unchanged"),
1081                         REBASE_FORCE),
1082                 OPT_BIT(0, "no-ff", &options.flags,
1083                         N_("cherry-pick all commits, even if unchanged"),
1084                         REBASE_FORCE),
1085                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1086                             ACTION_CONTINUE),
1087                 OPT_CMDMODE(0, "skip", &action,
1088                             N_("skip current patch and continue"), ACTION_SKIP),
1089                 OPT_CMDMODE(0, "abort", &action,
1090                             N_("abort and check out the original branch"),
1091                             ACTION_ABORT),
1092                 OPT_CMDMODE(0, "quit", &action,
1093                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1094                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1095                             "during an interactive rebase"), ACTION_EDIT_TODO),
1096                 OPT_CMDMODE(0, "show-current-patch", &action,
1097                             N_("show the patch file being applied or merged"),
1098                             ACTION_SHOW_CURRENT_PATCH),
1099                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1100                         N_("use merging strategies to rebase"),
1101                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1102                         parse_opt_merge },
1103                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1104                         N_("let the user edit the list of commits to rebase"),
1105                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1106                         parse_opt_interactive },
1107                 OPT_SET_INT('p', "preserve-merges", &options.type,
1108                             N_("(DEPRECATED) try to recreate merges instead of "
1109                                "ignoring them"), REBASE_PRESERVE_MERGES),
1110                 OPT_BOOL(0, "rerere-autoupdate",
1111                          &options.allow_rerere_autoupdate,
1112                          N_("allow rerere to update index with resolved "
1113                             "conflict")),
1114                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
1115                          N_("preserve empty commits during rebase")),
1116                 OPT_BOOL(0, "autosquash", &options.autosquash,
1117                          N_("move commits that begin with "
1118                             "squash!/fixup! under -i")),
1119                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1120                         N_("GPG-sign commits"),
1121                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1122                 OPT_BOOL(0, "autostash", &options.autostash,
1123                          N_("automatically stash/stash pop before and after")),
1124                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1125                                 N_("add exec lines after each commit of the "
1126                                    "editable list")),
1127                 OPT_BOOL(0, "allow-empty-message",
1128                          &options.allow_empty_message,
1129                          N_("allow rebasing commits with empty messages")),
1130                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1131                         N_("mode"),
1132                         N_("try to rebase merges instead of skipping them"),
1133                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1134                 OPT_BOOL(0, "fork-point", &fork_point,
1135                          N_("use 'merge-base --fork-point' to refine upstream")),
1136                 OPT_STRING('s', "strategy", &options.strategy,
1137                            N_("strategy"), N_("use the given merge strategy")),
1138                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1139                                 N_("option"),
1140                                 N_("pass the argument through to the merge "
1141                                    "strategy")),
1142                 OPT_BOOL(0, "root", &options.root,
1143                          N_("rebase all reachable commits up to the root(s)")),
1144                 OPT_BOOL(0, "reschedule-failed-exec",
1145                          &options.reschedule_failed_exec,
1146                          N_("automatically re-schedule any `exec` that fails")),
1147                 OPT_END(),
1148         };
1149         int i;
1150
1151         /*
1152          * NEEDSWORK: Once the builtin rebase has been tested enough
1153          * and git-legacy-rebase.sh is retired to contrib/, this preamble
1154          * can be removed.
1155          */
1156
1157         if (!use_builtin_rebase()) {
1158                 const char *path = mkpath("%s/git-legacy-rebase",
1159                                           git_exec_path());
1160
1161                 if (sane_execvp(path, (char **)argv) < 0)
1162                         die_errno(_("could not exec %s"), path);
1163                 else
1164                         BUG("sane_execvp() returned???");
1165         }
1166
1167         if (argc == 2 && !strcmp(argv[1], "-h"))
1168                 usage_with_options(builtin_rebase_usage,
1169                                    builtin_rebase_options);
1170
1171         prefix = setup_git_directory();
1172         trace_repo_setup(prefix);
1173         setup_work_tree();
1174
1175         git_config(rebase_config, &options);
1176
1177         strbuf_reset(&buf);
1178         strbuf_addf(&buf, "%s/applying", apply_dir());
1179         if(file_exists(buf.buf))
1180                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1181
1182         if (is_directory(apply_dir())) {
1183                 options.type = REBASE_AM;
1184                 options.state_dir = apply_dir();
1185         } else if (is_directory(merge_dir())) {
1186                 strbuf_reset(&buf);
1187                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1188                 if (is_directory(buf.buf)) {
1189                         options.type = REBASE_PRESERVE_MERGES;
1190                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1191                 } else {
1192                         strbuf_reset(&buf);
1193                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1194                         if(file_exists(buf.buf)) {
1195                                 options.type = REBASE_INTERACTIVE;
1196                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1197                         } else
1198                                 options.type = REBASE_MERGE;
1199                 }
1200                 options.state_dir = merge_dir();
1201         }
1202
1203         if (options.type != REBASE_UNSPECIFIED)
1204                 in_progress = 1;
1205
1206         total_argc = argc;
1207         argc = parse_options(argc, argv, prefix,
1208                              builtin_rebase_options,
1209                              builtin_rebase_usage, 0);
1210
1211         if (action != NO_ACTION && total_argc != 2) {
1212                 usage_with_options(builtin_rebase_usage,
1213                                    builtin_rebase_options);
1214         }
1215
1216         if (argc > 2)
1217                 usage_with_options(builtin_rebase_usage,
1218                                    builtin_rebase_options);
1219
1220         if (options.type == REBASE_PRESERVE_MERGES)
1221                 warning(_("git rebase --preserve-merges is deprecated. "
1222                           "Use --rebase-merges instead."));
1223
1224         if (action != NO_ACTION && !in_progress)
1225                 die(_("No rebase in progress?"));
1226         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1227
1228         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1229                 die(_("The --edit-todo action can only be used during "
1230                       "interactive rebase."));
1231
1232         if (trace2_is_enabled()) {
1233                 if (is_interactive(&options))
1234                         trace2_cmd_mode("interactive");
1235                 else if (exec.nr)
1236                         trace2_cmd_mode("interactive-exec");
1237                 else
1238                         trace2_cmd_mode(action_names[action]);
1239         }
1240
1241         switch (action) {
1242         case ACTION_CONTINUE: {
1243                 struct object_id head;
1244                 struct lock_file lock_file = LOCK_INIT;
1245                 int fd;
1246
1247                 options.action = "continue";
1248                 set_reflog_action(&options);
1249
1250                 /* Sanity check */
1251                 if (get_oid("HEAD", &head))
1252                         die(_("Cannot read HEAD"));
1253
1254                 fd = hold_locked_index(&lock_file, 0);
1255                 if (repo_read_index(the_repository) < 0)
1256                         die(_("could not read index"));
1257                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1258                               NULL);
1259                 if (0 <= fd)
1260                         repo_update_index_if_able(the_repository, &lock_file);
1261                 rollback_lock_file(&lock_file);
1262
1263                 if (has_unstaged_changes(the_repository, 1)) {
1264                         puts(_("You must edit all merge conflicts and then\n"
1265                                "mark them as resolved using git add"));
1266                         exit(1);
1267                 }
1268                 if (read_basic_state(&options))
1269                         exit(1);
1270                 goto run_rebase;
1271         }
1272         case ACTION_SKIP: {
1273                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1274
1275                 options.action = "skip";
1276                 set_reflog_action(&options);
1277
1278                 rerere_clear(the_repository, &merge_rr);
1279                 string_list_clear(&merge_rr, 1);
1280
1281                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1282                                NULL, NULL) < 0)
1283                         die(_("could not discard worktree changes"));
1284                 remove_branch_state(the_repository);
1285                 if (read_basic_state(&options))
1286                         exit(1);
1287                 goto run_rebase;
1288         }
1289         case ACTION_ABORT: {
1290                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1291                 options.action = "abort";
1292                 set_reflog_action(&options);
1293
1294                 rerere_clear(the_repository, &merge_rr);
1295                 string_list_clear(&merge_rr, 1);
1296
1297                 if (read_basic_state(&options))
1298                         exit(1);
1299                 if (reset_head(&options.orig_head, "reset",
1300                                options.head_name, RESET_HEAD_HARD,
1301                                NULL, NULL) < 0)
1302                         die(_("could not move back to %s"),
1303                             oid_to_hex(&options.orig_head));
1304                 remove_branch_state(the_repository);
1305                 ret = finish_rebase(&options);
1306                 goto cleanup;
1307         }
1308         case ACTION_QUIT: {
1309                 strbuf_reset(&buf);
1310                 strbuf_addstr(&buf, options.state_dir);
1311                 ret = !!remove_dir_recursively(&buf, 0);
1312                 if (ret)
1313                         die(_("could not remove '%s'"), options.state_dir);
1314                 goto cleanup;
1315         }
1316         case ACTION_EDIT_TODO:
1317                 options.action = "edit-todo";
1318                 options.dont_finish_rebase = 1;
1319                 goto run_rebase;
1320         case ACTION_SHOW_CURRENT_PATCH:
1321                 options.action = "show-current-patch";
1322                 options.dont_finish_rebase = 1;
1323                 goto run_rebase;
1324         case NO_ACTION:
1325                 break;
1326         default:
1327                 BUG("action: %d", action);
1328         }
1329
1330         /* Make sure no rebase is in progress */
1331         if (in_progress) {
1332                 const char *last_slash = strrchr(options.state_dir, '/');
1333                 const char *state_dir_base =
1334                         last_slash ? last_slash + 1 : options.state_dir;
1335                 const char *cmd_live_rebase =
1336                         "git rebase (--continue | --abort | --skip)";
1337                 strbuf_reset(&buf);
1338                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1339                 die(_("It seems that there is already a %s directory, and\n"
1340                       "I wonder if you are in the middle of another rebase.  "
1341                       "If that is the\n"
1342                       "case, please try\n\t%s\n"
1343                       "If that is not the case, please\n\t%s\n"
1344                       "and run me again.  I am stopping in case you still "
1345                       "have something\n"
1346                       "valuable there.\n"),
1347                     state_dir_base, cmd_live_rebase, buf.buf);
1348         }
1349
1350         for (i = 0; i < options.git_am_opts.argc; i++) {
1351                 const char *option = options.git_am_opts.argv[i], *p;
1352                 if (!strcmp(option, "--committer-date-is-author-date") ||
1353                     !strcmp(option, "--ignore-date") ||
1354                     !strcmp(option, "--whitespace=fix") ||
1355                     !strcmp(option, "--whitespace=strip"))
1356                         options.flags |= REBASE_FORCE;
1357                 else if (skip_prefix(option, "-C", &p)) {
1358                         while (*p)
1359                                 if (!isdigit(*(p++)))
1360                                         die(_("switch `C' expects a "
1361                                               "numerical value"));
1362                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1363                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1364                             strcmp(p, "error") && strcmp(p, "error-all"))
1365                                 die("Invalid whitespace option: '%s'", p);
1366                 }
1367         }
1368
1369         for (i = 0; i < exec.nr; i++)
1370                 if (check_exec_cmd(exec.items[i].string))
1371                         exit(1);
1372
1373         if (!(options.flags & REBASE_NO_QUIET))
1374                 argv_array_push(&options.git_am_opts, "-q");
1375
1376         if (options.keep_empty)
1377                 imply_interactive(&options, "--keep-empty");
1378
1379         if (gpg_sign) {
1380                 free(options.gpg_sign_opt);
1381                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1382         }
1383
1384         if (exec.nr) {
1385                 int i;
1386
1387                 imply_interactive(&options, "--exec");
1388
1389                 strbuf_reset(&buf);
1390                 for (i = 0; i < exec.nr; i++)
1391                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1392                 options.cmd = xstrdup(buf.buf);
1393         }
1394
1395         if (rebase_merges) {
1396                 if (!*rebase_merges)
1397                         ; /* default mode; do nothing */
1398                 else if (!strcmp("rebase-cousins", rebase_merges))
1399                         options.rebase_cousins = 1;
1400                 else if (strcmp("no-rebase-cousins", rebase_merges))
1401                         die(_("Unknown mode: %s"), rebase_merges);
1402                 options.rebase_merges = 1;
1403                 imply_interactive(&options, "--rebase-merges");
1404         }
1405
1406         if (strategy_options.nr) {
1407                 int i;
1408
1409                 if (!options.strategy)
1410                         options.strategy = "recursive";
1411
1412                 strbuf_reset(&buf);
1413                 for (i = 0; i < strategy_options.nr; i++)
1414                         strbuf_addf(&buf, " --%s",
1415                                     strategy_options.items[i].string);
1416                 options.strategy_opts = xstrdup(buf.buf);
1417         }
1418
1419         if (options.strategy) {
1420                 options.strategy = xstrdup(options.strategy);
1421                 switch (options.type) {
1422                 case REBASE_AM:
1423                         die(_("--strategy requires --merge or --interactive"));
1424                 case REBASE_MERGE:
1425                 case REBASE_INTERACTIVE:
1426                 case REBASE_PRESERVE_MERGES:
1427                         /* compatible */
1428                         break;
1429                 case REBASE_UNSPECIFIED:
1430                         options.type = REBASE_MERGE;
1431                         break;
1432                 default:
1433                         BUG("unhandled rebase type (%d)", options.type);
1434                 }
1435         }
1436
1437         if (options.type == REBASE_MERGE)
1438                 imply_interactive(&options, "--merge");
1439
1440         if (options.root && !options.onto_name)
1441                 imply_interactive(&options, "--root without --onto");
1442
1443         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1444                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1445
1446         switch (options.type) {
1447         case REBASE_MERGE:
1448         case REBASE_INTERACTIVE:
1449         case REBASE_PRESERVE_MERGES:
1450                 options.state_dir = merge_dir();
1451                 break;
1452         case REBASE_AM:
1453                 options.state_dir = apply_dir();
1454                 break;
1455         default:
1456                 /* the default rebase backend is `--am` */
1457                 options.type = REBASE_AM;
1458                 options.state_dir = apply_dir();
1459                 break;
1460         }
1461
1462         if (options.reschedule_failed_exec && !is_interactive(&options))
1463                 die(_("%s requires an interactive rebase"), "--reschedule-failed-exec");
1464
1465         if (options.git_am_opts.argc) {
1466                 /* all am options except -q are compatible only with --am */
1467                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1468                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1469                                 break;
1470
1471                 if (is_interactive(&options) && i >= 0)
1472                         die(_("cannot combine am options with either "
1473                               "interactive or merge options"));
1474         }
1475
1476         if (options.signoff) {
1477                 if (options.type == REBASE_PRESERVE_MERGES)
1478                         die("cannot combine '--signoff' with "
1479                             "'--preserve-merges'");
1480                 argv_array_push(&options.git_am_opts, "--signoff");
1481                 options.flags |= REBASE_FORCE;
1482         }
1483
1484         if (options.type == REBASE_PRESERVE_MERGES) {
1485                 /*
1486                  * Note: incompatibility with --signoff handled in signoff block above
1487                  * Note: incompatibility with --interactive is just a strong warning;
1488                  *       git-rebase.txt caveats with "unless you know what you are doing"
1489                  */
1490                 if (options.rebase_merges)
1491                         die(_("cannot combine '--preserve-merges' with "
1492                               "'--rebase-merges'"));
1493
1494                 if (options.reschedule_failed_exec)
1495                         die(_("error: cannot combine '--preserve-merges' with "
1496                               "'--reschedule-failed-exec'"));
1497         }
1498
1499         if (options.rebase_merges) {
1500                 if (strategy_options.nr)
1501                         die(_("cannot combine '--rebase-merges' with "
1502                               "'--strategy-option'"));
1503                 if (options.strategy)
1504                         die(_("cannot combine '--rebase-merges' with "
1505                               "'--strategy'"));
1506         }
1507
1508         if (!options.root) {
1509                 if (argc < 1) {
1510                         struct branch *branch;
1511
1512                         branch = branch_get(NULL);
1513                         options.upstream_name = branch_get_upstream(branch,
1514                                                                     NULL);
1515                         if (!options.upstream_name)
1516                                 error_on_missing_default_upstream();
1517                         if (fork_point < 0)
1518                                 fork_point = 1;
1519                 } else {
1520                         options.upstream_name = argv[0];
1521                         argc--;
1522                         argv++;
1523                         if (!strcmp(options.upstream_name, "-"))
1524                                 options.upstream_name = "@{-1}";
1525                 }
1526                 options.upstream = peel_committish(options.upstream_name);
1527                 if (!options.upstream)
1528                         die(_("invalid upstream '%s'"), options.upstream_name);
1529                 options.upstream_arg = options.upstream_name;
1530         } else {
1531                 if (!options.onto_name) {
1532                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1533                                         &squash_onto, NULL, NULL) < 0)
1534                                 die(_("Could not create new root commit"));
1535                         options.squash_onto = &squash_onto;
1536                         options.onto_name = squash_onto_name =
1537                                 xstrdup(oid_to_hex(&squash_onto));
1538                 }
1539                 options.upstream_name = NULL;
1540                 options.upstream = NULL;
1541                 if (argc > 1)
1542                         usage_with_options(builtin_rebase_usage,
1543                                            builtin_rebase_options);
1544                 options.upstream_arg = "--root";
1545         }
1546
1547         /* Make sure the branch to rebase onto is valid. */
1548         if (!options.onto_name)
1549                 options.onto_name = options.upstream_name;
1550         if (strstr(options.onto_name, "...")) {
1551                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
1552                         die(_("'%s': need exactly one merge base"),
1553                             options.onto_name);
1554                 options.onto = lookup_commit_or_die(&merge_base,
1555                                                     options.onto_name);
1556         } else {
1557                 options.onto = peel_committish(options.onto_name);
1558                 if (!options.onto)
1559                         die(_("Does not point to a valid commit '%s'"),
1560                                 options.onto_name);
1561         }
1562
1563         /*
1564          * If the branch to rebase is given, that is the branch we will rebase
1565          * branch_name -- branch/commit being rebased, or
1566          *                HEAD (already detached)
1567          * orig_head -- commit object name of tip of the branch before rebasing
1568          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1569          */
1570         if (argc == 1) {
1571                 /* Is it "rebase other branchname" or "rebase other commit"? */
1572                 branch_name = argv[0];
1573                 options.switch_to = argv[0];
1574
1575                 /* Is it a local branch? */
1576                 strbuf_reset(&buf);
1577                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1578                 if (!read_ref(buf.buf, &options.orig_head))
1579                         options.head_name = xstrdup(buf.buf);
1580                 /* If not is it a valid ref (branch or commit)? */
1581                 else if (!get_oid(branch_name, &options.orig_head))
1582                         options.head_name = NULL;
1583                 else
1584                         die(_("fatal: no such branch/commit '%s'"),
1585                             branch_name);
1586         } else if (argc == 0) {
1587                 /* Do not need to switch branches, we are already on it. */
1588                 options.head_name =
1589                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1590                                          &flags));
1591                 if (!options.head_name)
1592                         die(_("No such ref: %s"), "HEAD");
1593                 if (flags & REF_ISSYMREF) {
1594                         if (!skip_prefix(options.head_name,
1595                                          "refs/heads/", &branch_name))
1596                                 branch_name = options.head_name;
1597
1598                 } else {
1599                         free(options.head_name);
1600                         options.head_name = NULL;
1601                         branch_name = "HEAD";
1602                 }
1603                 if (get_oid("HEAD", &options.orig_head))
1604                         die(_("Could not resolve HEAD to a revision"));
1605         } else
1606                 BUG("unexpected number of arguments left to parse");
1607
1608         if (fork_point > 0) {
1609                 struct commit *head =
1610                         lookup_commit_reference(the_repository,
1611                                                 &options.orig_head);
1612                 options.restrict_revision =
1613                         get_fork_point(options.upstream_name, head);
1614         }
1615
1616         if (repo_read_index(the_repository) < 0)
1617                 die(_("could not read index"));
1618
1619         if (options.autostash) {
1620                 struct lock_file lock_file = LOCK_INIT;
1621                 int fd;
1622
1623                 fd = hold_locked_index(&lock_file, 0);
1624                 refresh_cache(REFRESH_QUIET);
1625                 if (0 <= fd)
1626                         repo_update_index_if_able(the_repository, &lock_file);
1627                 rollback_lock_file(&lock_file);
1628
1629                 if (has_unstaged_changes(the_repository, 1) ||
1630                     has_uncommitted_changes(the_repository, 1)) {
1631                         const char *autostash =
1632                                 state_dir_path("autostash", &options);
1633                         struct child_process stash = CHILD_PROCESS_INIT;
1634                         struct object_id oid;
1635                         struct commit *head =
1636                                 lookup_commit_reference(the_repository,
1637                                                         &options.orig_head);
1638
1639                         argv_array_pushl(&stash.args,
1640                                          "stash", "create", "autostash", NULL);
1641                         stash.git_cmd = 1;
1642                         stash.no_stdin = 1;
1643                         strbuf_reset(&buf);
1644                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1645                                 die(_("Cannot autostash"));
1646                         strbuf_trim_trailing_newline(&buf);
1647                         if (get_oid(buf.buf, &oid))
1648                                 die(_("Unexpected stash response: '%s'"),
1649                                     buf.buf);
1650                         strbuf_reset(&buf);
1651                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1652
1653                         if (safe_create_leading_directories_const(autostash))
1654                                 die(_("Could not create directory for '%s'"),
1655                                     options.state_dir);
1656                         write_file(autostash, "%s", oid_to_hex(&oid));
1657                         printf(_("Created autostash: %s\n"), buf.buf);
1658                         if (reset_head(&head->object.oid, "reset --hard",
1659                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1660                                 die(_("could not reset --hard"));
1661                         printf(_("HEAD is now at %s"),
1662                                find_unique_abbrev(&head->object.oid,
1663                                                   DEFAULT_ABBREV));
1664                         strbuf_reset(&buf);
1665                         pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1666                         if (buf.len > 0)
1667                                 printf(" %s", buf.buf);
1668                         putchar('\n');
1669
1670                         if (discard_index(the_repository->index) < 0 ||
1671                                 repo_read_index(the_repository) < 0)
1672                                 die(_("could not read index"));
1673                 }
1674         }
1675
1676         if (require_clean_work_tree(the_repository, "rebase",
1677                                     _("Please commit or stash them."), 1, 1)) {
1678                 ret = 1;
1679                 goto cleanup;
1680         }
1681
1682         /*
1683          * Now we are rebasing commits upstream..orig_head (or with --root,
1684          * everything leading up to orig_head) on top of onto.
1685          */
1686
1687         /*
1688          * Check if we are already based on onto with linear history,
1689          * but this should be done only when upstream and onto are the same
1690          * and if this is not an interactive rebase.
1691          */
1692         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1693             !is_interactive(&options) && !options.restrict_revision &&
1694             options.upstream &&
1695             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1696                 int flag;
1697
1698                 if (!(options.flags & REBASE_FORCE)) {
1699                         /* Lazily switch to the target branch if needed... */
1700                         if (options.switch_to) {
1701                                 struct object_id oid;
1702
1703                                 if (get_oid(options.switch_to, &oid) < 0) {
1704                                         ret = !!error(_("could not parse '%s'"),
1705                                                       options.switch_to);
1706                                         goto cleanup;
1707                                 }
1708
1709                                 strbuf_reset(&buf);
1710                                 strbuf_addf(&buf, "%s: checkout %s",
1711                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1712                                             options.switch_to);
1713                                 if (reset_head(&oid, "checkout",
1714                                                options.head_name,
1715                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1716                                                NULL, buf.buf) < 0) {
1717                                         ret = !!error(_("could not switch to "
1718                                                         "%s"),
1719                                                       options.switch_to);
1720                                         goto cleanup;
1721                                 }
1722                         }
1723
1724                         if (!(options.flags & REBASE_NO_QUIET))
1725                                 ; /* be quiet */
1726                         else if (!strcmp(branch_name, "HEAD") &&
1727                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1728                                 puts(_("HEAD is up to date."));
1729                         else
1730                                 printf(_("Current branch %s is up to date.\n"),
1731                                        branch_name);
1732                         ret = !!finish_rebase(&options);
1733                         goto cleanup;
1734                 } else if (!(options.flags & REBASE_NO_QUIET))
1735                         ; /* be quiet */
1736                 else if (!strcmp(branch_name, "HEAD") &&
1737                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1738                         puts(_("HEAD is up to date, rebase forced."));
1739                 else
1740                         printf(_("Current branch %s is up to date, rebase "
1741                                  "forced.\n"), branch_name);
1742         }
1743
1744         /* If a hook exists, give it a chance to interrupt*/
1745         if (!ok_to_skip_pre_rebase &&
1746             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1747                         argc ? argv[0] : NULL, NULL))
1748                 die(_("The pre-rebase hook refused to rebase."));
1749
1750         if (options.flags & REBASE_DIFFSTAT) {
1751                 struct diff_options opts;
1752
1753                 if (options.flags & REBASE_VERBOSE) {
1754                         if (is_null_oid(&merge_base))
1755                                 printf(_("Changes to %s:\n"),
1756                                        oid_to_hex(&options.onto->object.oid));
1757                         else
1758                                 printf(_("Changes from %s to %s:\n"),
1759                                        oid_to_hex(&merge_base),
1760                                        oid_to_hex(&options.onto->object.oid));
1761                 }
1762
1763                 /* We want color (if set), but no pager */
1764                 diff_setup(&opts);
1765                 opts.stat_width = -1; /* use full terminal width */
1766                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1767                 opts.output_format |=
1768                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1769                 opts.detect_rename = DIFF_DETECT_RENAME;
1770                 diff_setup_done(&opts);
1771                 diff_tree_oid(is_null_oid(&merge_base) ?
1772                               the_hash_algo->empty_tree : &merge_base,
1773                               &options.onto->object.oid, "", &opts);
1774                 diffcore_std(&opts);
1775                 diff_flush(&opts);
1776         }
1777
1778         if (is_interactive(&options))
1779                 goto run_rebase;
1780
1781         /* Detach HEAD and reset the tree */
1782         if (options.flags & REBASE_NO_QUIET)
1783                 printf(_("First, rewinding head to replay your work on top of "
1784                          "it...\n"));
1785
1786         strbuf_addf(&msg, "%s: checkout %s",
1787                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
1788         if (reset_head(&options.onto->object.oid, "checkout", NULL,
1789                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
1790                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1791                        NULL, msg.buf))
1792                 die(_("Could not detach HEAD"));
1793         strbuf_release(&msg);
1794
1795         /*
1796          * If the onto is a proper descendant of the tip of the branch, then
1797          * we just fast-forwarded.
1798          */
1799         strbuf_reset(&msg);
1800         if (!oidcmp(&merge_base, &options.orig_head)) {
1801                 printf(_("Fast-forwarded %s to %s.\n"),
1802                         branch_name, options.onto_name);
1803                 strbuf_addf(&msg, "rebase finished: %s onto %s",
1804                         options.head_name ? options.head_name : "detached HEAD",
1805                         oid_to_hex(&options.onto->object.oid));
1806                 reset_head(NULL, "Fast-forwarded", options.head_name,
1807                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
1808                 strbuf_release(&msg);
1809                 ret = !!finish_rebase(&options);
1810                 goto cleanup;
1811         }
1812
1813         strbuf_addf(&revisions, "%s..%s",
1814                     options.root ? oid_to_hex(&options.onto->object.oid) :
1815                     (options.restrict_revision ?
1816                      oid_to_hex(&options.restrict_revision->object.oid) :
1817                      oid_to_hex(&options.upstream->object.oid)),
1818                     oid_to_hex(&options.orig_head));
1819
1820         options.revisions = revisions.buf;
1821
1822 run_rebase:
1823         ret = !!run_specific_rebase(&options);
1824
1825 cleanup:
1826         strbuf_release(&revisions);
1827         free(options.head_name);
1828         free(options.gpg_sign_opt);
1829         free(options.cmd);
1830         free(squash_onto_name);
1831         return ret;
1832 }