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