builtin/rebase.c

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #define USE_THE_INDEX_VARIABLE
   8 #include "builtin.h"
   9 #include "run-command.h"
  10 #include "exec-cmd.h"
  11 #include "strvec.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 #include "sequencer.h"
  29 #include "rebase-interactive.h"
  30 #include "reset.h"
  31 #include "hook.h"
  32
  33 static char const * const builtin_rebase_usage[] = {
  34         N_("git rebase [-i] [options] [--exec <cmd>] "
  35                 "[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
  36         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  37                 "--root [<branch>]"),
  38         "git rebase --continue | --abort | --skip | --edit-todo",
  39         NULL
  40 };
  41
  42 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
  43 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
  44 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  45 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  46
  47 enum rebase_type {
  48         REBASE_UNSPECIFIED = -1,
  49         REBASE_APPLY,
  50         REBASE_MERGE
  51 };
  52
  53 enum empty_type {
  54         EMPTY_UNSPECIFIED = -1,
  55         EMPTY_DROP,
  56         EMPTY_KEEP,
  57         EMPTY_ASK
  58 };
  59
  60 enum action {
  61         ACTION_NONE = 0,
  62         ACTION_CONTINUE,
  63         ACTION_SKIP,
  64         ACTION_ABORT,
  65         ACTION_QUIT,
  66         ACTION_EDIT_TODO,
  67         ACTION_SHOW_CURRENT_PATCH
  68 };
  69
  70 static const char *action_names[] = {
  71         "undefined",
  72         "continue",
  73         "skip",
  74         "abort",
  75         "quit",
  76         "edit_todo",
  77         "show_current_patch"
  78 };
  79
  80 struct rebase_options {
  81         enum rebase_type type;
  82         enum empty_type empty;
  83         const char *default_backend;
  84         const char *state_dir;
  85         struct commit *upstream;
  86         const char *upstream_name;
  87         const char *upstream_arg;
  88         char *head_name;
  89         struct commit *orig_head;
  90         struct commit *onto;
  91         const char *onto_name;
  92         const char *revisions;
  93         const char *switch_to;
  94         int root, root_with_onto;
  95         struct object_id *squash_onto;
  96         struct commit *restrict_revision;
  97         int dont_finish_rebase;
  98         enum {
  99                 REBASE_NO_QUIET = 1<<0,
 100                 REBASE_VERBOSE = 1<<1,
 101                 REBASE_DIFFSTAT = 1<<2,
 102                 REBASE_FORCE = 1<<3,
 103                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
 104         } flags;
 105         struct strvec git_am_opts;
 106         enum action action;
 107         char *reflog_action;
 108         int signoff;
 109         int allow_rerere_autoupdate;
 110         int keep_empty;
 111         int autosquash;
 112         char *gpg_sign_opt;
 113         int autostash;
 114         int committer_date_is_author_date;
 115         int ignore_date;
 116         struct string_list exec;
 117         int allow_empty_message;
 118         int rebase_merges, rebase_cousins;
 119         char *strategy, *strategy_opts;
 120         struct strbuf git_format_patch_opt;
 121         int reschedule_failed_exec;
 122         int reapply_cherry_picks;
 123         int fork_point;
 124         int update_refs;
 125         int config_autosquash;
 126         int config_update_refs;
 127 };
 128
 129 #define REBASE_OPTIONS_INIT {                           \
 130                 .type = REBASE_UNSPECIFIED,             \
 131                 .empty = EMPTY_UNSPECIFIED,             \
 132                 .keep_empty = 1,                        \
 133                 .default_backend = "merge",             \
 134                 .flags = REBASE_NO_QUIET,               \
 135                 .git_am_opts = STRVEC_INIT,             \
 136                 .exec = STRING_LIST_INIT_NODUP,         \
 137                 .git_format_patch_opt = STRBUF_INIT,    \
 138                 .fork_point = -1,                       \
 139                 .reapply_cherry_picks = -1,             \
 140                 .allow_empty_message = 1,               \
 141                 .autosquash = -1,                       \
 142                 .config_autosquash = -1,                \
 143                 .update_refs = -1,                      \
 144                 .config_update_refs = -1,               \
 145         }
 146
 147 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 148 {
 149         struct replay_opts replay = REPLAY_OPTS_INIT;
 150
 151         replay.action = REPLAY_INTERACTIVE_REBASE;
 152         replay.strategy = NULL;
 153         sequencer_init_config(&replay);
 154
 155         replay.signoff = opts->signoff;
 156         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 157         if (opts->allow_rerere_autoupdate)
 158                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 159         replay.allow_empty = 1;
 160         replay.allow_empty_message = opts->allow_empty_message;
 161         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
 162         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
 163         replay.quiet = !(opts->flags & REBASE_NO_QUIET);
 164         replay.verbose = opts->flags & REBASE_VERBOSE;
 165         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 166         replay.committer_date_is_author_date =
 167                                         opts->committer_date_is_author_date;
 168         replay.ignore_date = opts->ignore_date;
 169         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 170         replay.reflog_action = xstrdup(opts->reflog_action);
 171         if (opts->strategy)
 172                 replay.strategy = xstrdup_or_null(opts->strategy);
 173         else if (!replay.strategy && replay.default_strategy) {
 174                 replay.strategy = replay.default_strategy;
 175                 replay.default_strategy = NULL;
 176         }
 177
 178         if (opts->strategy_opts)
 179                 parse_strategy_opts(&replay, opts->strategy_opts);
 180
 181         if (opts->squash_onto) {
 182                 oidcpy(&replay.squash_onto, opts->squash_onto);
 183                 replay.have_squash_onto = 1;
 184         }
 185
 186         return replay;
 187 }
 188
 189 static int edit_todo_file(unsigned flags)
 190 {
 191         const char *todo_file = rebase_path_todo();
 192         struct todo_list todo_list = TODO_LIST_INIT,
 193                 new_todo = TODO_LIST_INIT;
 194         int res = 0;
 195
 196         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 197                 return error_errno(_("could not read '%s'."), todo_file);
 198
 199         strbuf_stripspace(&todo_list.buf, 1);
 200         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 201         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 202                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 203                 res = error_errno(_("could not write '%s'"), todo_file);
 204
 205         todo_list_release(&todo_list);
 206         todo_list_release(&new_todo);
 207
 208         return res;
 209 }
 210
 211 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 212                                struct object_id *orig_head, char **revisions,
 213                                char **shortrevisions)
 214 {
 215         struct commit *base_rev = upstream ? upstream : onto;
 216         const char *shorthead;
 217
 218         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 219                              oid_to_hex(orig_head));
 220
 221         shorthead = find_unique_abbrev(orig_head, DEFAULT_ABBREV);
 222
 223         if (upstream) {
 224                 const char *shortrev;
 225
 226                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 227                                               DEFAULT_ABBREV);
 228
 229                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 230         } else
 231                 *shortrevisions = xstrdup(shorthead);
 232
 233         return 0;
 234 }
 235
 236 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 237                             struct commit *onto,
 238                             const struct object_id *orig_head)
 239 {
 240         FILE *interactive;
 241
 242         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 243                 return error_errno(_("could not create temporary %s"), merge_dir());
 244
 245         delete_reflog("REBASE_HEAD");
 246
 247         interactive = fopen(path_interactive(), "w");
 248         if (!interactive)
 249                 return error_errno(_("could not mark as interactive"));
 250         fclose(interactive);
 251
 252         return write_basic_state(opts, head_name, onto, orig_head);
 253 }
 254
 255 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 256 {
 257         int ret;
 258         char *revisions = NULL, *shortrevisions = NULL;
 259         struct strvec make_script_args = STRVEC_INIT;
 260         struct todo_list todo_list = TODO_LIST_INIT;
 261         struct replay_opts replay = get_replay_opts(opts);
 262
 263         if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head->object.oid,
 264                                 &revisions, &shortrevisions))
 265                 return -1;
 266
 267         if (init_basic_state(&replay,
 268                              opts->head_name ? opts->head_name : "detached HEAD",
 269                              opts->onto, &opts->orig_head->object.oid)) {
 270                 free(revisions);
 271                 free(shortrevisions);
 272
 273                 return -1;
 274         }
 275
 276         if (!opts->upstream && opts->squash_onto)
 277                 write_file(path_squash_onto(), "%s\n",
 278                            oid_to_hex(opts->squash_onto));
 279
 280         strvec_pushl(&make_script_args, "", revisions, NULL);
 281         if (opts->restrict_revision)
 282                 strvec_pushf(&make_script_args, "^%s",
 283                              oid_to_hex(&opts->restrict_revision->object.oid));
 284
 285         ret = sequencer_make_script(the_repository, &todo_list.buf,
 286                                     make_script_args.nr, make_script_args.v,
 287                                     flags);
 288
 289         if (ret)
 290                 error(_("could not generate todo list"));
 291         else {
 292                 discard_index(&the_index);
 293                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 294                                                 &todo_list))
 295                         BUG("unusable todo list");
 296
 297                 ret = complete_action(the_repository, &replay, flags,
 298                         shortrevisions, opts->onto_name, opts->onto,
 299                         &opts->orig_head->object.oid, &opts->exec,
 300                         opts->autosquash, opts->update_refs, &todo_list);
 301         }
 302
 303         free(revisions);
 304         free(shortrevisions);
 305         todo_list_release(&todo_list);
 306         strvec_clear(&make_script_args);
 307
 308         return ret;
 309 }
 310
 311 static int run_sequencer_rebase(struct rebase_options *opts)
 312 {
 313         unsigned flags = 0;
 314         int abbreviate_commands = 0, ret = 0;
 315
 316         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 317
 318         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 319         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 320         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 321         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 322         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 323         flags |= opts->reapply_cherry_picks ? TODO_LIST_REAPPLY_CHERRY_PICKS : 0;
 324         flags |= opts->flags & REBASE_NO_QUIET ? TODO_LIST_WARN_SKIPPED_CHERRY_PICKS : 0;
 325
 326         switch (opts->action) {
 327         case ACTION_NONE: {
 328                 if (!opts->onto && !opts->upstream)
 329                         die(_("a base commit must be provided with --upstream or --onto"));
 330
 331                 ret = do_interactive_rebase(opts, flags);
 332                 break;
 333         }
 334         case ACTION_SKIP: {
 335                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 336
 337                 rerere_clear(the_repository, &merge_rr);
 338         }
 339                 /* fallthrough */
 340         case ACTION_CONTINUE: {
 341                 struct replay_opts replay_opts = get_replay_opts(opts);
 342
 343                 ret = sequencer_continue(the_repository, &replay_opts);
 344                 break;
 345         }
 346         case ACTION_EDIT_TODO:
 347                 ret = edit_todo_file(flags);
 348                 break;
 349         case ACTION_SHOW_CURRENT_PATCH: {
 350                 struct child_process cmd = CHILD_PROCESS_INIT;
 351
 352                 cmd.git_cmd = 1;
 353                 strvec_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 354                 ret = run_command(&cmd);
 355
 356                 break;
 357         }
 358         default:
 359                 BUG("invalid command '%d'", opts->action);
 360         }
 361
 362         return ret;
 363 }
 364
 365 static void imply_merge(struct rebase_options *opts, const char *option);
 366 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 367                                 int unset)
 368 {
 369         struct rebase_options *opts = opt->value;
 370
 371         BUG_ON_OPT_ARG(arg);
 372
 373         imply_merge(opts, unset ? "--no-keep-empty" : "--keep-empty");
 374         opts->keep_empty = !unset;
 375         opts->type = REBASE_MERGE;
 376         return 0;
 377 }
 378
 379 static int is_merge(struct rebase_options *opts)
 380 {
 381         return opts->type == REBASE_MERGE;
 382 }
 383
 384 static void imply_merge(struct rebase_options *opts, const char *option)
 385 {
 386         switch (opts->type) {
 387         case REBASE_APPLY:
 388                 die(_("%s requires the merge backend"), option);
 389                 break;
 390         case REBASE_MERGE:
 391                 break;
 392         default:
 393                 opts->type = REBASE_MERGE; /* implied */
 394                 break;
 395         }
 396 }
 397
 398 /* Returns the filename prefixed by the state_dir */
 399 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 400 {
 401         static struct strbuf path = STRBUF_INIT;
 402         static size_t prefix_len;
 403
 404         if (!prefix_len) {
 405                 strbuf_addf(&path, "%s/", opts->state_dir);
 406                 prefix_len = path.len;
 407         }
 408
 409         strbuf_setlen(&path, prefix_len);
 410         strbuf_addstr(&path, filename);
 411         return path.buf;
 412 }
 413
 414 /* Initialize the rebase options from the state directory. */
 415 static int read_basic_state(struct rebase_options *opts)
 416 {
 417         struct strbuf head_name = STRBUF_INIT;
 418         struct strbuf buf = STRBUF_INIT;
 419         struct object_id oid;
 420
 421         if (!read_oneliner(&head_name, state_dir_path("head-name", opts),
 422                            READ_ONELINER_WARN_MISSING) ||
 423             !read_oneliner(&buf, state_dir_path("onto", opts),
 424                            READ_ONELINER_WARN_MISSING))
 425                 return -1;
 426         opts->head_name = starts_with(head_name.buf, "refs/") ?
 427                 xstrdup(head_name.buf) : NULL;
 428         strbuf_release(&head_name);
 429         if (get_oid_hex(buf.buf, &oid) ||
 430             !(opts->onto = lookup_commit_object(the_repository, &oid)))
 431                 return error(_("invalid onto: '%s'"), buf.buf);
 432
 433         /*
 434          * We always write to orig-head, but interactive rebase used to write to
 435          * head. Fall back to reading from head to cover for the case that the
 436          * user upgraded git with an ongoing interactive rebase.
 437          */
 438         strbuf_reset(&buf);
 439         if (file_exists(state_dir_path("orig-head", opts))) {
 440                 if (!read_oneliner(&buf, state_dir_path("orig-head", opts),
 441                                    READ_ONELINER_WARN_MISSING))
 442                         return -1;
 443         } else if (!read_oneliner(&buf, state_dir_path("head", opts),
 444                                   READ_ONELINER_WARN_MISSING))
 445                 return -1;
 446         if (get_oid_hex(buf.buf, &oid) ||
 447             !(opts->orig_head = lookup_commit_object(the_repository, &oid)))
 448                 return error(_("invalid orig-head: '%s'"), buf.buf);
 449
 450         if (file_exists(state_dir_path("quiet", opts)))
 451                 opts->flags &= ~REBASE_NO_QUIET;
 452         else
 453                 opts->flags |= REBASE_NO_QUIET;
 454
 455         if (file_exists(state_dir_path("verbose", opts)))
 456                 opts->flags |= REBASE_VERBOSE;
 457
 458         if (file_exists(state_dir_path("signoff", opts))) {
 459                 opts->signoff = 1;
 460                 opts->flags |= REBASE_FORCE;
 461         }
 462
 463         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 464                 strbuf_reset(&buf);
 465                 if (!read_oneliner(&buf, state_dir_path("allow_rerere_autoupdate", opts),
 466                                    READ_ONELINER_WARN_MISSING))
 467                         return -1;
 468                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 469                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 470                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 471                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 472                 else
 473                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 474                                   "'%s'"), buf.buf);
 475         }
 476
 477         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 478                 strbuf_reset(&buf);
 479                 if (!read_oneliner(&buf, state_dir_path("gpg_sign_opt", opts),
 480                                    READ_ONELINER_WARN_MISSING))
 481                         return -1;
 482                 free(opts->gpg_sign_opt);
 483                 opts->gpg_sign_opt = xstrdup(buf.buf);
 484         }
 485
 486         if (file_exists(state_dir_path("strategy", opts))) {
 487                 strbuf_reset(&buf);
 488                 if (!read_oneliner(&buf, state_dir_path("strategy", opts),
 489                                    READ_ONELINER_WARN_MISSING))
 490                         return -1;
 491                 free(opts->strategy);
 492                 opts->strategy = xstrdup(buf.buf);
 493         }
 494
 495         if (file_exists(state_dir_path("strategy_opts", opts))) {
 496                 strbuf_reset(&buf);
 497                 if (!read_oneliner(&buf, state_dir_path("strategy_opts", opts),
 498                                    READ_ONELINER_WARN_MISSING))
 499                         return -1;
 500                 free(opts->strategy_opts);
 501                 opts->strategy_opts = xstrdup(buf.buf);
 502         }
 503
 504         strbuf_release(&buf);
 505
 506         return 0;
 507 }
 508
 509 static int rebase_write_basic_state(struct rebase_options *opts)
 510 {
 511         write_file(state_dir_path("head-name", opts), "%s",
 512                    opts->head_name ? opts->head_name : "detached HEAD");
 513         write_file(state_dir_path("onto", opts), "%s",
 514                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 515         write_file(state_dir_path("orig-head", opts), "%s",
 516                    oid_to_hex(&opts->orig_head->object.oid));
 517         if (!(opts->flags & REBASE_NO_QUIET))
 518                 write_file(state_dir_path("quiet", opts), "%s", "");
 519         if (opts->flags & REBASE_VERBOSE)
 520                 write_file(state_dir_path("verbose", opts), "%s", "");
 521         if (opts->strategy)
 522                 write_file(state_dir_path("strategy", opts), "%s",
 523                            opts->strategy);
 524         if (opts->strategy_opts)
 525                 write_file(state_dir_path("strategy_opts", opts), "%s",
 526                            opts->strategy_opts);
 527         if (opts->allow_rerere_autoupdate > 0)
 528                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 529                            "-%s-rerere-autoupdate",
 530                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 531                                 "" : "-no");
 532         if (opts->gpg_sign_opt)
 533                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 534                            opts->gpg_sign_opt);
 535         if (opts->signoff)
 536                 write_file(state_dir_path("signoff", opts), "--signoff");
 537
 538         return 0;
 539 }
 540
 541 static int finish_rebase(struct rebase_options *opts)
 542 {
 543         struct strbuf dir = STRBUF_INIT;
 544         int ret = 0;
 545
 546         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 547         unlink(git_path_auto_merge(the_repository));
 548         apply_autostash(state_dir_path("autostash", opts));
 549         /*
 550          * We ignore errors in 'git maintenance run --auto', since the
 551          * user should see them.
 552          */
 553         run_auto_maintenance(!(opts->flags & (REBASE_NO_QUIET|REBASE_VERBOSE)));
 554         if (opts->type == REBASE_MERGE) {
 555                 struct replay_opts replay = REPLAY_OPTS_INIT;
 556
 557                 replay.action = REPLAY_INTERACTIVE_REBASE;
 558                 ret = sequencer_remove_state(&replay);
 559         } else {
 560                 strbuf_addstr(&dir, opts->state_dir);
 561                 if (remove_dir_recursively(&dir, 0))
 562                         ret = error(_("could not remove '%s'"),
 563                                     opts->state_dir);
 564                 strbuf_release(&dir);
 565         }
 566
 567         return ret;
 568 }
 569
 570 static int move_to_original_branch(struct rebase_options *opts)
 571 {
 572         struct strbuf branch_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 573         struct reset_head_opts ropts = { 0 };
 574         int ret;
 575
 576         if (!opts->head_name)
 577                 return 0; /* nothing to move back to */
 578
 579         if (!opts->onto)
 580                 BUG("move_to_original_branch without onto");
 581
 582         strbuf_addf(&branch_reflog, "%s (finish): %s onto %s",
 583                     opts->reflog_action,
 584                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 585         strbuf_addf(&head_reflog, "%s (finish): returning to %s",
 586                     opts->reflog_action, opts->head_name);
 587         ropts.branch = opts->head_name;
 588         ropts.flags = RESET_HEAD_REFS_ONLY;
 589         ropts.branch_msg = branch_reflog.buf;
 590         ropts.head_msg = head_reflog.buf;
 591         ret = reset_head(the_repository, &ropts);
 592
 593         strbuf_release(&branch_reflog);
 594         strbuf_release(&head_reflog);
 595         return ret;
 596 }
 597
 598 static const char *resolvemsg =
 599 N_("Resolve all conflicts manually, mark them as resolved with\n"
 600 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 601 "You can instead skip this commit: run \"git rebase --skip\".\n"
 602 "To abort and get back to the state before \"git rebase\", run "
 603 "\"git rebase --abort\".");
 604
 605 static int run_am(struct rebase_options *opts)
 606 {
 607         struct child_process am = CHILD_PROCESS_INIT;
 608         struct child_process format_patch = CHILD_PROCESS_INIT;
 609         struct strbuf revisions = STRBUF_INIT;
 610         int status;
 611         char *rebased_patches;
 612
 613         am.git_cmd = 1;
 614         strvec_push(&am.args, "am");
 615         strvec_pushf(&am.env, GIT_REFLOG_ACTION_ENVIRONMENT "=%s (pick)",
 616                      opts->reflog_action);
 617         if (opts->action == ACTION_CONTINUE) {
 618                 strvec_push(&am.args, "--resolved");
 619                 strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 620                 if (opts->gpg_sign_opt)
 621                         strvec_push(&am.args, opts->gpg_sign_opt);
 622                 status = run_command(&am);
 623                 if (status)
 624                         return status;
 625
 626                 return move_to_original_branch(opts);
 627         }
 628         if (opts->action == ACTION_SKIP) {
 629                 strvec_push(&am.args, "--skip");
 630                 strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 631                 status = run_command(&am);
 632                 if (status)
 633                         return status;
 634
 635                 return move_to_original_branch(opts);
 636         }
 637         if (opts->action == ACTION_SHOW_CURRENT_PATCH) {
 638                 strvec_push(&am.args, "--show-current-patch");
 639                 return run_command(&am);
 640         }
 641
 642         strbuf_addf(&revisions, "%s...%s",
 643                     oid_to_hex(opts->root ?
 644                                /* this is now equivalent to !opts->upstream */
 645                                &opts->onto->object.oid :
 646                                &opts->upstream->object.oid),
 647                     oid_to_hex(&opts->orig_head->object.oid));
 648
 649         rebased_patches = xstrdup(git_path("rebased-patches"));
 650         format_patch.out = open(rebased_patches,
 651                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
 652         if (format_patch.out < 0) {
 653                 status = error_errno(_("could not open '%s' for writing"),
 654                                      rebased_patches);
 655                 free(rebased_patches);
 656                 strvec_clear(&am.args);
 657                 return status;
 658         }
 659
 660         format_patch.git_cmd = 1;
 661         strvec_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
 662                      "--full-index", "--cherry-pick", "--right-only",
 663                      "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
 664                      "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
 665                      "--no-base", NULL);
 666         if (opts->git_format_patch_opt.len)
 667                 strvec_split(&format_patch.args,
 668                              opts->git_format_patch_opt.buf);
 669         strvec_push(&format_patch.args, revisions.buf);
 670         if (opts->restrict_revision)
 671                 strvec_pushf(&format_patch.args, "^%s",
 672                              oid_to_hex(&opts->restrict_revision->object.oid));
 673
 674         status = run_command(&format_patch);
 675         if (status) {
 676                 struct reset_head_opts ropts = { 0 };
 677                 unlink(rebased_patches);
 678                 free(rebased_patches);
 679                 strvec_clear(&am.args);
 680
 681                 ropts.oid = &opts->orig_head->object.oid;
 682                 ropts.branch = opts->head_name;
 683                 ropts.default_reflog_action = opts->reflog_action;
 684                 reset_head(the_repository, &ropts);
 685                 error(_("\ngit encountered an error while preparing the "
 686                         "patches to replay\n"
 687                         "these revisions:\n"
 688                         "\n    %s\n\n"
 689                         "As a result, git cannot rebase them."),
 690                       opts->revisions);
 691
 692                 strbuf_release(&revisions);
 693                 return status;
 694         }
 695         strbuf_release(&revisions);
 696
 697         am.in = open(rebased_patches, O_RDONLY);
 698         if (am.in < 0) {
 699                 status = error_errno(_("could not open '%s' for reading"),
 700                                      rebased_patches);
 701                 free(rebased_patches);
 702                 strvec_clear(&am.args);
 703                 return status;
 704         }
 705
 706         strvec_pushv(&am.args, opts->git_am_opts.v);
 707         strvec_push(&am.args, "--rebasing");
 708         strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 709         strvec_push(&am.args, "--patch-format=mboxrd");
 710         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
 711                 strvec_push(&am.args, "--rerere-autoupdate");
 712         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
 713                 strvec_push(&am.args, "--no-rerere-autoupdate");
 714         if (opts->gpg_sign_opt)
 715                 strvec_push(&am.args, opts->gpg_sign_opt);
 716         status = run_command(&am);
 717         unlink(rebased_patches);
 718         free(rebased_patches);
 719
 720         if (!status) {
 721                 return move_to_original_branch(opts);
 722         }
 723
 724         if (is_directory(opts->state_dir))
 725                 rebase_write_basic_state(opts);
 726
 727         return status;
 728 }
 729
 730 static int run_specific_rebase(struct rebase_options *opts)
 731 {
 732         int status;
 733
 734         if (opts->type == REBASE_MERGE) {
 735                 /* Run sequencer-based rebase */
 736                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
 737                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 738                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
 739                         opts->autosquash = 0;
 740                 }
 741                 if (opts->gpg_sign_opt) {
 742                         /* remove the leading "-S" */
 743                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
 744                         free(opts->gpg_sign_opt);
 745                         opts->gpg_sign_opt = tmp;
 746                 }
 747
 748                 status = run_sequencer_rebase(opts);
 749         } else if (opts->type == REBASE_APPLY)
 750                 status = run_am(opts);
 751         else
 752                 BUG("Unhandled rebase type %d", opts->type);
 753
 754         if (opts->dont_finish_rebase)
 755                 ; /* do nothing */
 756         else if (opts->type == REBASE_MERGE)
 757                 ; /* merge backend cleans up after itself */
 758         else if (status == 0) {
 759                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 760                         finish_rebase(opts);
 761         } else if (status == 2) {
 762                 struct strbuf dir = STRBUF_INIT;
 763
 764                 apply_autostash(state_dir_path("autostash", opts));
 765                 strbuf_addstr(&dir, opts->state_dir);
 766                 remove_dir_recursively(&dir, 0);
 767                 strbuf_release(&dir);
 768                 die("Nothing to do");
 769         }
 770
 771         return status ? -1 : 0;
 772 }
 773
 774 static int rebase_config(const char *var, const char *value, void *data)
 775 {
 776         struct rebase_options *opts = data;
 777
 778         if (!strcmp(var, "rebase.stat")) {
 779                 if (git_config_bool(var, value))
 780                         opts->flags |= REBASE_DIFFSTAT;
 781                 else
 782                         opts->flags &= ~REBASE_DIFFSTAT;
 783                 return 0;
 784         }
 785
 786         if (!strcmp(var, "rebase.autosquash")) {
 787                 opts->config_autosquash = git_config_bool(var, value);
 788                 return 0;
 789         }
 790
 791         if (!strcmp(var, "commit.gpgsign")) {
 792                 free(opts->gpg_sign_opt);
 793                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 794                         xstrdup("-S") : NULL;
 795                 return 0;
 796         }
 797
 798         if (!strcmp(var, "rebase.autostash")) {
 799                 opts->autostash = git_config_bool(var, value);
 800                 return 0;
 801         }
 802
 803         if (!strcmp(var, "rebase.updaterefs")) {
 804                 opts->config_update_refs = git_config_bool(var, value);
 805                 return 0;
 806         }
 807
 808         if (!strcmp(var, "rebase.reschedulefailedexec")) {
 809                 opts->reschedule_failed_exec = git_config_bool(var, value);
 810                 return 0;
 811         }
 812
 813         if (!strcmp(var, "rebase.forkpoint")) {
 814                 opts->fork_point = git_config_bool(var, value) ? -1 : 0;
 815                 return 0;
 816         }
 817
 818         if (!strcmp(var, "rebase.backend")) {
 819                 return git_config_string(&opts->default_backend, var, value);
 820         }
 821
 822         return git_default_config(var, value, data);
 823 }
 824
 825 static int checkout_up_to_date(struct rebase_options *options)
 826 {
 827         struct strbuf buf = STRBUF_INIT;
 828         struct reset_head_opts ropts = { 0 };
 829         int ret = 0;
 830
 831         strbuf_addf(&buf, "%s: checkout %s",
 832                     options->reflog_action, options->switch_to);
 833         ropts.oid = &options->orig_head->object.oid;
 834         ropts.branch = options->head_name;
 835         ropts.flags = RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 836         if (!ropts.branch)
 837                 ropts.flags |=  RESET_HEAD_DETACH;
 838         ropts.head_msg = buf.buf;
 839         if (reset_head(the_repository, &ropts) < 0)
 840                 ret = error(_("could not switch to %s"), options->switch_to);
 841         strbuf_release(&buf);
 842
 843         return ret;
 844 }
 845
 846 /*
 847  * Determines whether the commits in from..to are linear, i.e. contain
 848  * no merge commits. This function *expects* `from` to be an ancestor of
 849  * `to`.
 850  */
 851 static int is_linear_history(struct commit *from, struct commit *to)
 852 {
 853         while (to && to != from) {
 854                 parse_commit(to);
 855                 if (!to->parents)
 856                         return 1;
 857                 if (to->parents->next)
 858                         return 0;
 859                 to = to->parents->item;
 860         }
 861         return 1;
 862 }
 863
 864 static int can_fast_forward(struct commit *onto, struct commit *upstream,
 865                             struct commit *restrict_revision,
 866                             struct commit *head, struct object_id *branch_base)
 867 {
 868         struct commit_list *merge_bases = NULL;
 869         int res = 0;
 870
 871         if (is_null_oid(branch_base))
 872                 goto done; /* fill_branch_base() found multiple merge bases */
 873
 874         if (!oideq(branch_base, &onto->object.oid))
 875                 goto done;
 876
 877         if (restrict_revision && !oideq(&restrict_revision->object.oid, branch_base))
 878                 goto done;
 879
 880         if (!upstream)
 881                 goto done;
 882
 883         merge_bases = get_merge_bases(upstream, head);
 884         if (!merge_bases || merge_bases->next)
 885                 goto done;
 886
 887         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
 888                 goto done;
 889
 890         res = 1;
 891
 892 done:
 893         free_commit_list(merge_bases);
 894         return res && is_linear_history(onto, head);
 895 }
 896
 897 static void fill_branch_base(struct rebase_options *options,
 898                             struct object_id *branch_base)
 899 {
 900         struct commit_list *merge_bases = NULL;
 901
 902         merge_bases = get_merge_bases(options->onto, options->orig_head);
 903         if (!merge_bases || merge_bases->next)
 904                 oidcpy(branch_base, null_oid());
 905         else
 906                 oidcpy(branch_base, &merge_bases->item->object.oid);
 907
 908         free_commit_list(merge_bases);
 909 }
 910
 911 static int parse_opt_am(const struct option *opt, const char *arg, int unset)
 912 {
 913         struct rebase_options *opts = opt->value;
 914
 915         BUG_ON_OPT_NEG(unset);
 916         BUG_ON_OPT_ARG(arg);
 917
 918         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_APPLY)
 919             die(_("apply options and merge options cannot be used together"));
 920
 921         opts->type = REBASE_APPLY;
 922
 923         return 0;
 924 }
 925
 926 /* -i followed by -m is still -i */
 927 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 928 {
 929         struct rebase_options *opts = opt->value;
 930
 931         BUG_ON_OPT_NEG(unset);
 932         BUG_ON_OPT_ARG(arg);
 933
 934         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_MERGE)
 935             die(_("apply options and merge options cannot be used together"));
 936
 937         opts->type = REBASE_MERGE;
 938
 939         return 0;
 940 }
 941
 942 /* -i followed by -r is still explicitly interactive, but -r alone is not */
 943 static int parse_opt_interactive(const struct option *opt, const char *arg,
 944                                  int unset)
 945 {
 946         struct rebase_options *opts = opt->value;
 947
 948         BUG_ON_OPT_NEG(unset);
 949         BUG_ON_OPT_ARG(arg);
 950
 951         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_MERGE)
 952             die(_("apply options and merge options cannot be used together"));
 953
 954         opts->type = REBASE_MERGE;
 955         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 956
 957         return 0;
 958 }
 959
 960 static enum empty_type parse_empty_value(const char *value)
 961 {
 962         if (!strcasecmp(value, "drop"))
 963                 return EMPTY_DROP;
 964         else if (!strcasecmp(value, "keep"))
 965                 return EMPTY_KEEP;
 966         else if (!strcasecmp(value, "ask"))
 967                 return EMPTY_ASK;
 968
 969         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
 970 }
 971
 972 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
 973 {
 974         struct rebase_options *options = opt->value;
 975         enum empty_type value = parse_empty_value(arg);
 976
 977         BUG_ON_OPT_NEG(unset);
 978
 979         options->empty = value;
 980         return 0;
 981 }
 982
 983 static void NORETURN error_on_missing_default_upstream(void)
 984 {
 985         struct branch *current_branch = branch_get(NULL);
 986
 987         printf(_("%s\n"
 988                  "Please specify which branch you want to rebase against.\n"
 989                  "See git-rebase(1) for details.\n"
 990                  "\n"
 991                  "    git rebase '<branch>'\n"
 992                  "\n"),
 993                 current_branch ? _("There is no tracking information for "
 994                         "the current branch.") :
 995                         _("You are not currently on a branch."));
 996
 997         if (current_branch) {
 998                 const char *remote = current_branch->remote_name;
 999
1000                 if (!remote)
1001                         remote = _("<remote>");
1002
1003                 printf(_("If you wish to set tracking information for this "
1004                          "branch you can do so with:\n"
1005                          "\n"
1006                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1007                          "\n"),
1008                        remote, current_branch->name);
1009         }
1010         exit(1);
1011 }
1012
1013 static int check_exec_cmd(const char *cmd)
1014 {
1015         if (strchr(cmd, '\n'))
1016                 return error(_("exec commands cannot contain newlines"));
1017
1018         /* Does the command consist purely of whitespace? */
1019         if (!cmd[strspn(cmd, " \t\r\f\v")])
1020                 return error(_("empty exec command"));
1021
1022         return 0;
1023 }
1024
1025 int cmd_rebase(int argc, const char **argv, const char *prefix)
1026 {
1027         struct rebase_options options = REBASE_OPTIONS_INIT;
1028         const char *branch_name;
1029         int ret, flags, total_argc, in_progress = 0;
1030         int keep_base = 0;
1031         int ok_to_skip_pre_rebase = 0;
1032         struct strbuf msg = STRBUF_INIT;
1033         struct strbuf revisions = STRBUF_INIT;
1034         struct strbuf buf = STRBUF_INIT;
1035         struct object_id branch_base;
1036         int ignore_whitespace = 0;
1037         const char *gpg_sign = NULL;
1038         const char *rebase_merges = NULL;
1039         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1040         struct object_id squash_onto;
1041         char *squash_onto_name = NULL;
1042         int reschedule_failed_exec = -1;
1043         int allow_preemptive_ff = 1;
1044         int preserve_merges_selected = 0;
1045         struct reset_head_opts ropts = { 0 };
1046         struct option builtin_rebase_options[] = {
1047                 OPT_STRING(0, "onto", &options.onto_name,
1048                            N_("revision"),
1049                            N_("rebase onto given branch instead of upstream")),
1050                 OPT_BOOL(0, "keep-base", &keep_base,
1051                          N_("use the merge-base of upstream and branch as the current base")),
1052                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1053                          N_("allow pre-rebase hook to run")),
1054                 OPT_NEGBIT('q', "quiet", &options.flags,
1055                            N_("be quiet. implies --no-stat"),
1056                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1057                 OPT_BIT('v', "verbose", &options.flags,
1058                         N_("display a diffstat of what changed upstream"),
1059                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1060                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1061                         N_("do not show diffstat of what changed upstream"),
1062                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1063                 OPT_BOOL(0, "signoff", &options.signoff,
1064                          N_("add a Signed-off-by trailer to each commit")),
1065                 OPT_BOOL(0, "committer-date-is-author-date",
1066                          &options.committer_date_is_author_date,
1067                          N_("make committer date match author date")),
1068                 OPT_BOOL(0, "reset-author-date", &options.ignore_date,
1069                          N_("ignore author date and use current date")),
1070                 OPT_HIDDEN_BOOL(0, "ignore-date", &options.ignore_date,
1071                                 N_("synonym of --reset-author-date")),
1072                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1073                                   N_("passed to 'git apply'"), 0),
1074                 OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
1075                          N_("ignore changes in whitespace")),
1076                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1077                                   N_("action"), N_("passed to 'git apply'"), 0),
1078                 OPT_BIT('f', "force-rebase", &options.flags,
1079                         N_("cherry-pick all commits, even if unchanged"),
1080                         REBASE_FORCE),
1081                 OPT_BIT(0, "no-ff", &options.flags,
1082                         N_("cherry-pick all commits, even if unchanged"),
1083                         REBASE_FORCE),
1084                 OPT_CMDMODE(0, "continue", &options.action, N_("continue"),
1085                             ACTION_CONTINUE),
1086                 OPT_CMDMODE(0, "skip", &options.action,
1087                             N_("skip current patch and continue"), ACTION_SKIP),
1088                 OPT_CMDMODE(0, "abort", &options.action,
1089                             N_("abort and check out the original branch"),
1090                             ACTION_ABORT),
1091                 OPT_CMDMODE(0, "quit", &options.action,
1092                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1093                 OPT_CMDMODE(0, "edit-todo", &options.action, N_("edit the todo list "
1094                             "during an interactive rebase"), ACTION_EDIT_TODO),
1095                 OPT_CMDMODE(0, "show-current-patch", &options.action,
1096                             N_("show the patch file being applied or merged"),
1097                             ACTION_SHOW_CURRENT_PATCH),
1098                 OPT_CALLBACK_F(0, "apply", &options, NULL,
1099                         N_("use apply strategies to rebase"),
1100                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1101                         parse_opt_am),
1102                 OPT_CALLBACK_F('m', "merge", &options, NULL,
1103                         N_("use merging strategies to rebase"),
1104                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1105                         parse_opt_merge),
1106                 OPT_CALLBACK_F('i', "interactive", &options, NULL,
1107                         N_("let the user edit the list of commits to rebase"),
1108                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1109                         parse_opt_interactive),
1110                 OPT_SET_INT_F('p', "preserve-merges", &preserve_merges_selected,
1111                               N_("(REMOVED) was: try to recreate merges "
1112                                  "instead of ignoring them"),
1113                               1, PARSE_OPT_HIDDEN),
1114                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1115                 OPT_CALLBACK_F(0, "empty", &options, "{drop,keep,ask}",
1116                                N_("how to handle commits that become empty"),
1117                                PARSE_OPT_NONEG, parse_opt_empty),
1118                 OPT_CALLBACK_F('k', "keep-empty", &options, NULL,
1119                         N_("keep commits which start empty"),
1120                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1121                         parse_opt_keep_empty),
1122                 OPT_BOOL(0, "autosquash", &options.autosquash,
1123                          N_("move commits that begin with "
1124                             "squash!/fixup! under -i")),
1125                 OPT_BOOL(0, "update-refs", &options.update_refs,
1126                          N_("update branches that point to commits "
1127                             "that are being rebased")),
1128                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1129                         N_("GPG-sign commits"),
1130                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1131                 OPT_AUTOSTASH(&options.autostash),
1132                 OPT_STRING_LIST('x', "exec", &options.exec, N_("exec"),
1133                                 N_("add exec lines after each commit of the "
1134                                    "editable list")),
1135                 OPT_BOOL_F(0, "allow-empty-message",
1136                            &options.allow_empty_message,
1137                            N_("allow rebasing commits with empty messages"),
1138                            PARSE_OPT_HIDDEN),
1139                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1140                         N_("mode"),
1141                         N_("try to rebase merges instead of skipping them"),
1142                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1143                 OPT_BOOL(0, "fork-point", &options.fork_point,
1144                          N_("use 'merge-base --fork-point' to refine upstream")),
1145                 OPT_STRING('s', "strategy", &options.strategy,
1146                            N_("strategy"), N_("use the given merge strategy")),
1147                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1148                                 N_("option"),
1149                                 N_("pass the argument through to the merge "
1150                                    "strategy")),
1151                 OPT_BOOL(0, "root", &options.root,
1152                          N_("rebase all reachable commits up to the root(s)")),
1153                 OPT_BOOL(0, "reschedule-failed-exec",
1154                          &reschedule_failed_exec,
1155                          N_("automatically re-schedule any `exec` that fails")),
1156                 OPT_BOOL(0, "reapply-cherry-picks", &options.reapply_cherry_picks,
1157                          N_("apply all changes, even those already present upstream")),
1158                 OPT_END(),
1159         };
1160         int i;
1161
1162         if (argc == 2 && !strcmp(argv[1], "-h"))
1163                 usage_with_options(builtin_rebase_usage,
1164                                    builtin_rebase_options);
1165
1166         prepare_repo_settings(the_repository);
1167         the_repository->settings.command_requires_full_index = 0;
1168
1169         git_config(rebase_config, &options);
1170         /* options.gpg_sign_opt will be either "-S" or NULL */
1171         gpg_sign = options.gpg_sign_opt ? "" : NULL;
1172         FREE_AND_NULL(options.gpg_sign_opt);
1173
1174         strbuf_reset(&buf);
1175         strbuf_addf(&buf, "%s/applying", apply_dir());
1176         if(file_exists(buf.buf))
1177                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1178
1179         if (is_directory(apply_dir())) {
1180                 options.type = REBASE_APPLY;
1181                 options.state_dir = apply_dir();
1182         } else if (is_directory(merge_dir())) {
1183                 strbuf_reset(&buf);
1184                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1185                 if (!(options.action == ACTION_ABORT) && is_directory(buf.buf)) {
1186                         die(_("`rebase --preserve-merges` (-p) is no longer supported.\n"
1187                         "Use `git rebase --abort` to terminate current rebase.\n"
1188                         "Or downgrade to v2.33, or earlier, to complete the rebase."));
1189                 } else {
1190                         strbuf_reset(&buf);
1191                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1192                         options.type = REBASE_MERGE;
1193                         if (file_exists(buf.buf))
1194                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1195                 }
1196                 options.state_dir = merge_dir();
1197         }
1198
1199         if (options.type != REBASE_UNSPECIFIED)
1200                 in_progress = 1;
1201
1202         total_argc = argc;
1203         argc = parse_options(argc, argv, prefix,
1204                              builtin_rebase_options,
1205                              builtin_rebase_usage, 0);
1206
1207         if (preserve_merges_selected)
1208                 die(_("--preserve-merges was replaced by --rebase-merges\n"
1209                         "Note: Your `pull.rebase` configuration may also be set to 'preserve',\n"
1210                         "which is no longer supported; use 'merges' instead"));
1211
1212         if (options.action != ACTION_NONE && total_argc != 2) {
1213                 usage_with_options(builtin_rebase_usage,
1214                                    builtin_rebase_options);
1215         }
1216
1217         if (argc > 2)
1218                 usage_with_options(builtin_rebase_usage,
1219                                    builtin_rebase_options);
1220
1221         if (keep_base) {
1222                 if (options.onto_name)
1223                         die(_("options '%s' and '%s' cannot be used together"), "--keep-base", "--onto");
1224                 if (options.root)
1225                         die(_("options '%s' and '%s' cannot be used together"), "--keep-base", "--root");
1226                 /*
1227                  * --keep-base defaults to --no-fork-point to keep the
1228                  * base the same.
1229                  */
1230                 if (options.fork_point < 0)
1231                         options.fork_point = 0;
1232         }
1233         if (options.root && options.fork_point > 0)
1234                 die(_("options '%s' and '%s' cannot be used together"), "--root", "--fork-point");
1235
1236         if (options.action != ACTION_NONE && !in_progress)
1237                 die(_("No rebase in progress?"));
1238
1239         if (options.action == ACTION_EDIT_TODO && !is_merge(&options))
1240                 die(_("The --edit-todo action can only be used during "
1241                       "interactive rebase."));
1242
1243         if (trace2_is_enabled()) {
1244                 if (is_merge(&options))
1245                         trace2_cmd_mode("interactive");
1246                 else if (options.exec.nr)
1247                         trace2_cmd_mode("interactive-exec");
1248                 else
1249                         trace2_cmd_mode(action_names[options.action]);
1250         }
1251
1252         options.reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1253         options.reflog_action =
1254                 xstrdup(options.reflog_action ? options.reflog_action : "rebase");
1255
1256         switch (options.action) {
1257         case ACTION_CONTINUE: {
1258                 struct object_id head;
1259                 struct lock_file lock_file = LOCK_INIT;
1260                 int fd;
1261
1262                 /* Sanity check */
1263                 if (get_oid("HEAD", &head))
1264                         die(_("Cannot read HEAD"));
1265
1266                 fd = repo_hold_locked_index(the_repository, &lock_file, 0);
1267                 if (repo_read_index(the_repository) < 0)
1268                         die(_("could not read index"));
1269                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1270                               NULL);
1271                 if (0 <= fd)
1272                         repo_update_index_if_able(the_repository, &lock_file);
1273                 rollback_lock_file(&lock_file);
1274
1275                 if (has_unstaged_changes(the_repository, 1)) {
1276                         puts(_("You must edit all merge conflicts and then\n"
1277                                "mark them as resolved using git add"));
1278                         exit(1);
1279                 }
1280                 if (read_basic_state(&options))
1281                         exit(1);
1282                 goto run_rebase;
1283         }
1284         case ACTION_SKIP: {
1285                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1286
1287                 rerere_clear(the_repository, &merge_rr);
1288                 string_list_clear(&merge_rr, 1);
1289                 ropts.flags = RESET_HEAD_HARD;
1290                 if (reset_head(the_repository, &ropts) < 0)
1291                         die(_("could not discard worktree changes"));
1292                 remove_branch_state(the_repository, 0);
1293                 if (read_basic_state(&options))
1294                         exit(1);
1295                 goto run_rebase;
1296         }
1297         case ACTION_ABORT: {
1298                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1299                 struct strbuf head_msg = STRBUF_INIT;
1300
1301                 rerere_clear(the_repository, &merge_rr);
1302                 string_list_clear(&merge_rr, 1);
1303
1304                 if (read_basic_state(&options))
1305                         exit(1);
1306
1307                 strbuf_addf(&head_msg, "%s (abort): returning to %s",
1308                             options.reflog_action,
1309                             options.head_name ? options.head_name
1310                                               : oid_to_hex(&options.orig_head->object.oid));
1311                 ropts.oid = &options.orig_head->object.oid;
1312                 ropts.head_msg = head_msg.buf;
1313                 ropts.branch = options.head_name;
1314                 ropts.flags = RESET_HEAD_HARD;
1315                 if (reset_head(the_repository, &ropts) < 0)
1316                         die(_("could not move back to %s"),
1317                             oid_to_hex(&options.orig_head->object.oid));
1318                 strbuf_release(&head_msg);
1319                 remove_branch_state(the_repository, 0);
1320                 ret = finish_rebase(&options);
1321                 goto cleanup;
1322         }
1323         case ACTION_QUIT: {
1324                 save_autostash(state_dir_path("autostash", &options));
1325                 if (options.type == REBASE_MERGE) {
1326                         struct replay_opts replay = REPLAY_OPTS_INIT;
1327
1328                         replay.action = REPLAY_INTERACTIVE_REBASE;
1329                         ret = sequencer_remove_state(&replay);
1330                 } else {
1331                         strbuf_reset(&buf);
1332                         strbuf_addstr(&buf, options.state_dir);
1333                         ret = remove_dir_recursively(&buf, 0);
1334                         if (ret)
1335                                 error(_("could not remove '%s'"),
1336                                        options.state_dir);
1337                 }
1338                 goto cleanup;
1339         }
1340         case ACTION_EDIT_TODO:
1341                 options.dont_finish_rebase = 1;
1342                 goto run_rebase;
1343         case ACTION_SHOW_CURRENT_PATCH:
1344                 options.dont_finish_rebase = 1;
1345                 goto run_rebase;
1346         case ACTION_NONE:
1347                 break;
1348         default:
1349                 BUG("action: %d", options.action);
1350         }
1351
1352         /* Make sure no rebase is in progress */
1353         if (in_progress) {
1354                 const char *last_slash = strrchr(options.state_dir, '/');
1355                 const char *state_dir_base =
1356                         last_slash ? last_slash + 1 : options.state_dir;
1357                 const char *cmd_live_rebase =
1358                         "git rebase (--continue | --abort | --skip)";
1359                 strbuf_reset(&buf);
1360                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1361                 die(_("It seems that there is already a %s directory, and\n"
1362                       "I wonder if you are in the middle of another rebase.  "
1363                       "If that is the\n"
1364                       "case, please try\n\t%s\n"
1365                       "If that is not the case, please\n\t%s\n"
1366                       "and run me again.  I am stopping in case you still "
1367                       "have something\n"
1368                       "valuable there.\n"),
1369                     state_dir_base, cmd_live_rebase, buf.buf);
1370         }
1371
1372         if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
1373             (options.action != ACTION_NONE) ||
1374             (options.exec.nr > 0) ||
1375             (options.autosquash == -1 && options.config_autosquash == 1) ||
1376             options.autosquash == 1) {
1377                 allow_preemptive_ff = 0;
1378         }
1379         if (options.committer_date_is_author_date || options.ignore_date)
1380                 options.flags |= REBASE_FORCE;
1381
1382         for (i = 0; i < options.git_am_opts.nr; i++) {
1383                 const char *option = options.git_am_opts.v[i], *p;
1384                 if (!strcmp(option, "--whitespace=fix") ||
1385                     !strcmp(option, "--whitespace=strip"))
1386                         allow_preemptive_ff = 0;
1387                 else if (skip_prefix(option, "-C", &p)) {
1388                         while (*p)
1389                                 if (!isdigit(*(p++)))
1390                                         die(_("switch `C' expects a "
1391                                               "numerical value"));
1392                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1393                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1394                             strcmp(p, "error") && strcmp(p, "error-all"))
1395                                 die("Invalid whitespace option: '%s'", p);
1396                 }
1397         }
1398
1399         for (i = 0; i < options.exec.nr; i++)
1400                 if (check_exec_cmd(options.exec.items[i].string))
1401                         exit(1);
1402
1403         if (!(options.flags & REBASE_NO_QUIET))
1404                 strvec_push(&options.git_am_opts, "-q");
1405
1406         if (options.empty != EMPTY_UNSPECIFIED)
1407                 imply_merge(&options, "--empty");
1408
1409         if (options.reapply_cherry_picks < 0)
1410                 /*
1411                  * We default to --no-reapply-cherry-picks unless
1412                  * --keep-base is given; when --keep-base is given, we want
1413                  * to default to --reapply-cherry-picks.
1414                  */
1415                 options.reapply_cherry_picks = keep_base;
1416         else if (!keep_base)
1417                 /*
1418                  * The apply backend always searches for and drops cherry
1419                  * picks.  This is often not wanted with --keep-base, so
1420                  * --keep-base allows --reapply-cherry-picks to be
1421                  * simulated by altering the upstream such that
1422                  * cherry-picks cannot be detected and thus all commits are
1423                  * reapplied.  Thus, --[no-]reapply-cherry-picks is
1424                  * supported when --keep-base is specified, but not when
1425                  * --keep-base is left out.
1426                  */
1427                 imply_merge(&options, options.reapply_cherry_picks ?
1428                                           "--reapply-cherry-picks" :
1429                                           "--no-reapply-cherry-picks");
1430
1431         if (gpg_sign)
1432                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1433
1434         if (options.exec.nr)
1435                 imply_merge(&options, "--exec");
1436
1437         if (rebase_merges) {
1438                 if (!*rebase_merges)
1439                         ; /* default mode; do nothing */
1440                 else if (!strcmp("rebase-cousins", rebase_merges))
1441                         options.rebase_cousins = 1;
1442                 else if (strcmp("no-rebase-cousins", rebase_merges))
1443                         die(_("Unknown mode: %s"), rebase_merges);
1444                 options.rebase_merges = 1;
1445                 imply_merge(&options, "--rebase-merges");
1446         }
1447
1448         if (options.type == REBASE_APPLY) {
1449                 if (ignore_whitespace)
1450                         strvec_push(&options.git_am_opts,
1451                                     "--ignore-whitespace");
1452                 if (options.committer_date_is_author_date)
1453                         strvec_push(&options.git_am_opts,
1454                                     "--committer-date-is-author-date");
1455                 if (options.ignore_date)
1456                         strvec_push(&options.git_am_opts, "--ignore-date");
1457         } else {
1458                 /* REBASE_MERGE */
1459                 if (ignore_whitespace) {
1460                         string_list_append(&strategy_options,
1461                                            "ignore-space-change");
1462                 }
1463         }
1464
1465         if (strategy_options.nr) {
1466                 int i;
1467
1468                 if (!options.strategy)
1469                         options.strategy = "ort";
1470
1471                 strbuf_reset(&buf);
1472                 for (i = 0; i < strategy_options.nr; i++)
1473                         strbuf_addf(&buf, " --%s",
1474                                     strategy_options.items[i].string);
1475                 options.strategy_opts = xstrdup(buf.buf);
1476         }
1477
1478         if (options.strategy) {
1479                 options.strategy = xstrdup(options.strategy);
1480                 switch (options.type) {
1481                 case REBASE_APPLY:
1482                         die(_("--strategy requires --merge or --interactive"));
1483                 case REBASE_MERGE:
1484                         /* compatible */
1485                         break;
1486                 case REBASE_UNSPECIFIED:
1487                         options.type = REBASE_MERGE;
1488                         break;
1489                 default:
1490                         BUG("unhandled rebase type (%d)", options.type);
1491                 }
1492         }
1493
1494         if (options.type == REBASE_MERGE)
1495                 imply_merge(&options, "--merge");
1496
1497         if (options.root && !options.onto_name)
1498                 imply_merge(&options, "--root without --onto");
1499
1500         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1501                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1502
1503         if (options.git_am_opts.nr || options.type == REBASE_APPLY) {
1504                 /* all am options except -q are compatible only with --apply */
1505                 for (i = options.git_am_opts.nr - 1; i >= 0; i--)
1506                         if (strcmp(options.git_am_opts.v[i], "-q"))
1507                                 break;
1508
1509                 if (i >= 0 || options.type == REBASE_APPLY) {
1510                         if (is_merge(&options))
1511                                 die(_("apply options and merge options "
1512                                           "cannot be used together"));
1513                         else if (options.autosquash == -1 && options.config_autosquash == 1)
1514                                 die(_("apply options are incompatible with rebase.autosquash.  Consider adding --no-autosquash"));
1515                         else if (options.update_refs == -1 && options.config_update_refs == 1)
1516                                 die(_("apply options are incompatible with rebase.updateRefs.  Consider adding --no-update-refs"));
1517                         else
1518                                 options.type = REBASE_APPLY;
1519                 }
1520         }
1521
1522         if (options.update_refs == 1)
1523                 imply_merge(&options, "--update-refs");
1524         options.update_refs = (options.update_refs >= 0) ? options.update_refs :
1525                              ((options.config_update_refs >= 0) ? options.config_update_refs : 0);
1526
1527         if (options.autosquash == 1)
1528                 imply_merge(&options, "--autosquash");
1529         options.autosquash = (options.autosquash >= 0) ? options.autosquash :
1530                              ((options.config_autosquash >= 0) ? options.config_autosquash : 0);
1531
1532         if (options.type == REBASE_UNSPECIFIED) {
1533                 if (!strcmp(options.default_backend, "merge"))
1534                         imply_merge(&options, "--merge");
1535                 else if (!strcmp(options.default_backend, "apply"))
1536                         options.type = REBASE_APPLY;
1537                 else
1538                         die(_("Unknown rebase backend: %s"),
1539                             options.default_backend);
1540         }
1541
1542         if (options.type == REBASE_MERGE &&
1543             !options.strategy &&
1544             getenv("GIT_TEST_MERGE_ALGORITHM"))
1545                 options.strategy = xstrdup(getenv("GIT_TEST_MERGE_ALGORITHM"));
1546
1547         switch (options.type) {
1548         case REBASE_MERGE:
1549                 options.state_dir = merge_dir();
1550                 break;
1551         case REBASE_APPLY:
1552                 options.state_dir = apply_dir();
1553                 break;
1554         default:
1555                 BUG("options.type was just set above; should be unreachable.");
1556         }
1557
1558         if (options.empty == EMPTY_UNSPECIFIED) {
1559                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1560                         options.empty = EMPTY_ASK;
1561                 else if (options.exec.nr > 0)
1562                         options.empty = EMPTY_KEEP;
1563                 else
1564                         options.empty = EMPTY_DROP;
1565         }
1566         if (reschedule_failed_exec > 0 && !is_merge(&options))
1567                 die(_("--reschedule-failed-exec requires "
1568                       "--exec or --interactive"));
1569         if (reschedule_failed_exec >= 0)
1570                 options.reschedule_failed_exec = reschedule_failed_exec;
1571
1572         if (options.signoff) {
1573                 strvec_push(&options.git_am_opts, "--signoff");
1574                 options.flags |= REBASE_FORCE;
1575         }
1576
1577         if (!options.root) {
1578                 if (argc < 1) {
1579                         struct branch *branch;
1580
1581                         branch = branch_get(NULL);
1582                         options.upstream_name = branch_get_upstream(branch,
1583                                                                     NULL);
1584                         if (!options.upstream_name)
1585                                 error_on_missing_default_upstream();
1586                         if (options.fork_point < 0)
1587                                 options.fork_point = 1;
1588                 } else {
1589                         options.upstream_name = argv[0];
1590                         argc--;
1591                         argv++;
1592                         if (!strcmp(options.upstream_name, "-"))
1593                                 options.upstream_name = "@{-1}";
1594                 }
1595                 options.upstream =
1596                         lookup_commit_reference_by_name(options.upstream_name);
1597                 if (!options.upstream)
1598                         die(_("invalid upstream '%s'"), options.upstream_name);
1599                 options.upstream_arg = options.upstream_name;
1600         } else {
1601                 if (!options.onto_name) {
1602                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1603                                         &squash_onto, NULL, NULL) < 0)
1604                                 die(_("Could not create new root commit"));
1605                         options.squash_onto = &squash_onto;
1606                         options.onto_name = squash_onto_name =
1607                                 xstrdup(oid_to_hex(&squash_onto));
1608                 } else
1609                         options.root_with_onto = 1;
1610
1611                 options.upstream_name = NULL;
1612                 options.upstream = NULL;
1613                 if (argc > 1)
1614                         usage_with_options(builtin_rebase_usage,
1615                                            builtin_rebase_options);
1616                 options.upstream_arg = "--root";
1617         }
1618
1619         /*
1620          * If the branch to rebase is given, that is the branch we will rebase
1621          * branch_name -- branch/commit being rebased, or
1622          *                HEAD (already detached)
1623          * orig_head -- commit object name of tip of the branch before rebasing
1624          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1625          */
1626         if (argc == 1) {
1627                 /* Is it "rebase other branchname" or "rebase other commit"? */
1628                 struct object_id branch_oid;
1629                 branch_name = argv[0];
1630                 options.switch_to = argv[0];
1631
1632                 /* Is it a local branch? */
1633                 strbuf_reset(&buf);
1634                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1635                 if (!read_ref(buf.buf, &branch_oid)) {
1636                         die_if_checked_out(buf.buf, 1);
1637                         options.head_name = xstrdup(buf.buf);
1638                         options.orig_head =
1639                                 lookup_commit_object(the_repository,
1640                                                      &branch_oid);
1641                 /* If not is it a valid ref (branch or commit)? */
1642                 } else {
1643                         options.orig_head =
1644                                 lookup_commit_reference_by_name(branch_name);
1645                         options.head_name = NULL;
1646                 }
1647                 if (!options.orig_head)
1648                         die(_("no such branch/commit '%s'"), branch_name);
1649         } else if (argc == 0) {
1650                 /* Do not need to switch branches, we are already on it. */
1651                 options.head_name =
1652                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1653                                          &flags));
1654                 if (!options.head_name)
1655                         die(_("No such ref: %s"), "HEAD");
1656                 if (flags & REF_ISSYMREF) {
1657                         if (!skip_prefix(options.head_name,
1658                                          "refs/heads/", &branch_name))
1659                                 branch_name = options.head_name;
1660
1661                 } else {
1662                         FREE_AND_NULL(options.head_name);
1663                         branch_name = "HEAD";
1664                 }
1665                 options.orig_head = lookup_commit_reference_by_name("HEAD");
1666                 if (!options.orig_head)
1667                         die(_("Could not resolve HEAD to a commit"));
1668         } else
1669                 BUG("unexpected number of arguments left to parse");
1670
1671         /* Make sure the branch to rebase onto is valid. */
1672         if (keep_base) {
1673                 strbuf_reset(&buf);
1674                 strbuf_addstr(&buf, options.upstream_name);
1675                 strbuf_addstr(&buf, "...");
1676                 strbuf_addstr(&buf, branch_name);
1677                 options.onto_name = xstrdup(buf.buf);
1678         } else if (!options.onto_name)
1679                 options.onto_name = options.upstream_name;
1680         if (strstr(options.onto_name, "...")) {
1681                 if (get_oid_mb(options.onto_name, &branch_base) < 0) {
1682                         if (keep_base)
1683                                 die(_("'%s': need exactly one merge base with branch"),
1684                                     options.upstream_name);
1685                         else
1686                                 die(_("'%s': need exactly one merge base"),
1687                                     options.onto_name);
1688                 }
1689                 options.onto = lookup_commit_or_die(&branch_base,
1690                                                     options.onto_name);
1691         } else {
1692                 options.onto =
1693                         lookup_commit_reference_by_name(options.onto_name);
1694                 if (!options.onto)
1695                         die(_("Does not point to a valid commit '%s'"),
1696                                 options.onto_name);
1697                 fill_branch_base(&options, &branch_base);
1698         }
1699
1700         if (keep_base && options.reapply_cherry_picks)
1701                 options.upstream = options.onto;
1702
1703         if (options.fork_point > 0)
1704                 options.restrict_revision =
1705                         get_fork_point(options.upstream_name, options.orig_head);
1706
1707         if (repo_read_index(the_repository) < 0)
1708                 die(_("could not read index"));
1709
1710         if (options.autostash)
1711                 create_autostash(the_repository,
1712                                  state_dir_path("autostash", &options));
1713
1714
1715         if (require_clean_work_tree(the_repository, "rebase",
1716                                     _("Please commit or stash them."), 1, 1)) {
1717                 ret = -1;
1718                 goto cleanup;
1719         }
1720
1721         /*
1722          * Now we are rebasing commits upstream..orig_head (or with --root,
1723          * everything leading up to orig_head) on top of onto.
1724          */
1725
1726         /*
1727          * Check if we are already based on onto with linear history,
1728          * in which case we could fast-forward without replacing the commits
1729          * with new commits recreated by replaying their changes.
1730          */
1731         if (allow_preemptive_ff &&
1732             can_fast_forward(options.onto, options.upstream, options.restrict_revision,
1733                              options.orig_head, &branch_base)) {
1734                 int flag;
1735
1736                 if (!(options.flags & REBASE_FORCE)) {
1737                         /* Lazily switch to the target branch if needed... */
1738                         if (options.switch_to) {
1739                                 ret = checkout_up_to_date(&options);
1740                                 if (ret)
1741                                         goto cleanup;
1742                         }
1743
1744                         if (!(options.flags & REBASE_NO_QUIET))
1745                                 ; /* be quiet */
1746                         else if (!strcmp(branch_name, "HEAD") &&
1747                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1748                                 puts(_("HEAD is up to date."));
1749                         else
1750                                 printf(_("Current branch %s is up to date.\n"),
1751                                        branch_name);
1752                         ret = finish_rebase(&options);
1753                         goto cleanup;
1754                 } else if (!(options.flags & REBASE_NO_QUIET))
1755                         ; /* be quiet */
1756                 else if (!strcmp(branch_name, "HEAD") &&
1757                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1758                         puts(_("HEAD is up to date, rebase forced."));
1759                 else
1760                         printf(_("Current branch %s is up to date, rebase "
1761                                  "forced.\n"), branch_name);
1762         }
1763
1764         /* If a hook exists, give it a chance to interrupt*/
1765         if (!ok_to_skip_pre_rebase &&
1766             run_hooks_l("pre-rebase", options.upstream_arg,
1767                         argc ? argv[0] : NULL, NULL))
1768                 die(_("The pre-rebase hook refused to rebase."));
1769
1770         if (options.flags & REBASE_DIFFSTAT) {
1771                 struct diff_options opts;
1772
1773                 if (options.flags & REBASE_VERBOSE) {
1774                         if (is_null_oid(&branch_base))
1775                                 printf(_("Changes to %s:\n"),
1776                                        oid_to_hex(&options.onto->object.oid));
1777                         else
1778                                 printf(_("Changes from %s to %s:\n"),
1779                                        oid_to_hex(&branch_base),
1780                                        oid_to_hex(&options.onto->object.oid));
1781                 }
1782
1783                 /* We want color (if set), but no pager */
1784                 diff_setup(&opts);
1785                 opts.stat_width = -1; /* use full terminal width */
1786                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1787                 opts.output_format |=
1788                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1789                 opts.detect_rename = DIFF_DETECT_RENAME;
1790                 diff_setup_done(&opts);
1791                 diff_tree_oid(is_null_oid(&branch_base) ?
1792                               the_hash_algo->empty_tree : &branch_base,
1793                               &options.onto->object.oid, "", &opts);
1794                 diffcore_std(&opts);
1795                 diff_flush(&opts);
1796         }
1797
1798         if (is_merge(&options))
1799                 goto run_rebase;
1800
1801         /* Detach HEAD and reset the tree */
1802         if (options.flags & REBASE_NO_QUIET)
1803                 printf(_("First, rewinding head to replay your work on top of "
1804                          "it...\n"));
1805
1806         strbuf_addf(&msg, "%s (start): checkout %s",
1807                     options.reflog_action, options.onto_name);
1808         ropts.oid = &options.onto->object.oid;
1809         ropts.orig_head = &options.orig_head->object.oid,
1810         ropts.flags = RESET_HEAD_DETACH | RESET_ORIG_HEAD |
1811                         RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
1812         ropts.head_msg = msg.buf;
1813         ropts.default_reflog_action = options.reflog_action;
1814         if (reset_head(the_repository, &ropts))
1815                 die(_("Could not detach HEAD"));
1816         strbuf_release(&msg);
1817
1818         /*
1819          * If the onto is a proper descendant of the tip of the branch, then
1820          * we just fast-forwarded.
1821          */
1822         if (oideq(&branch_base, &options.orig_head->object.oid)) {
1823                 printf(_("Fast-forwarded %s to %s.\n"),
1824                         branch_name, options.onto_name);
1825                 move_to_original_branch(&options);
1826                 ret = finish_rebase(&options);
1827                 goto cleanup;
1828         }
1829
1830         strbuf_addf(&revisions, "%s..%s",
1831                     options.root ? oid_to_hex(&options.onto->object.oid) :
1832                     (options.restrict_revision ?
1833                      oid_to_hex(&options.restrict_revision->object.oid) :
1834                      oid_to_hex(&options.upstream->object.oid)),
1835                     oid_to_hex(&options.orig_head->object.oid));
1836
1837         options.revisions = revisions.buf;
1838
1839 run_rebase:
1840         ret = run_specific_rebase(&options);
1841
1842 cleanup:
1843         strbuf_release(&buf);
1844         strbuf_release(&revisions);
1845         free(options.reflog_action);
1846         free(options.head_name);
1847         strvec_clear(&options.git_am_opts);
1848         free(options.gpg_sign_opt);
1849         string_list_clear(&options.exec, 0);
1850         free(options.strategy);
1851         strbuf_release(&options.git_format_patch_opt);
1852         free(squash_onto_name);
1853         string_list_clear(&strategy_options, 0);
1854         return !!ret;
1855 }