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 "abspath.h"
  10 #include "environment.h"
  11 #include "gettext.h"
  12 #include "hex.h"
  13 #include "run-command.h"
  14 #include "exec-cmd.h"
  15 #include "strvec.h"
  16 #include "dir.h"
  17 #include "packfile.h"
  18 #include "refs.h"
  19 #include "quote.h"
  20 #include "config.h"
  21 #include "cache-tree.h"
  22 #include "unpack-trees.h"
  23 #include "lockfile.h"
  24 #include "object-file.h"
  25 #include "object-name.h"
  26 #include "parse-options.h"
  27 #include "path.h"
  28 #include "commit.h"
  29 #include "diff.h"
  30 #include "wt-status.h"
  31 #include "revision.h"
  32 #include "commit-reach.h"
  33 #include "rerere.h"
  34 #include "branch.h"
  35 #include "sequencer.h"
  36 #include "rebase-interactive.h"
  37 #include "reset.h"
  38 #include "trace2.h"
  39 #include "hook.h"
  40
  41 static char const * const builtin_rebase_usage[] = {
  42         N_("git rebase [-i] [options] [--exec <cmd>] "
  43                 "[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
  44         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  45                 "--root [<branch>]"),
  46         "git rebase --continue | --abort | --skip | --edit-todo",
  47         NULL
  48 };
  49
  50 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
  51 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
  52 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  53 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  54
  55 enum rebase_type {
  56         REBASE_UNSPECIFIED = -1,
  57         REBASE_APPLY,
  58         REBASE_MERGE
  59 };
  60
  61 enum empty_type {
  62         EMPTY_UNSPECIFIED = -1,
  63         EMPTY_DROP,
  64         EMPTY_KEEP,
  65         EMPTY_ASK
  66 };
  67
  68 enum action {
  69         ACTION_NONE = 0,
  70         ACTION_CONTINUE,
  71         ACTION_SKIP,
  72         ACTION_ABORT,
  73         ACTION_QUIT,
  74         ACTION_EDIT_TODO,
  75         ACTION_SHOW_CURRENT_PATCH
  76 };
  77
  78 static const char *action_names[] = {
  79         "undefined",
  80         "continue",
  81         "skip",
  82         "abort",
  83         "quit",
  84         "edit_todo",
  85         "show_current_patch"
  86 };
  87
  88 struct rebase_options {
  89         enum rebase_type type;
  90         enum empty_type empty;
  91         const char *default_backend;
  92         const char *state_dir;
  93         struct commit *upstream;
  94         const char *upstream_name;
  95         const char *upstream_arg;
  96         char *head_name;
  97         struct commit *orig_head;
  98         struct commit *onto;
  99         const char *onto_name;
 100         const char *revisions;
 101         const char *switch_to;
 102         int root, root_with_onto;
 103         struct object_id *squash_onto;
 104         struct commit *restrict_revision;
 105         int dont_finish_rebase;
 106         enum {
 107                 REBASE_NO_QUIET = 1<<0,
 108                 REBASE_VERBOSE = 1<<1,
 109                 REBASE_DIFFSTAT = 1<<2,
 110                 REBASE_FORCE = 1<<3,
 111                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
 112         } flags;
 113         struct strvec git_am_opts;
 114         enum action action;
 115         char *reflog_action;
 116         int signoff;
 117         int allow_rerere_autoupdate;
 118         int keep_empty;
 119         int autosquash;
 120         char *gpg_sign_opt;
 121         int autostash;
 122         int committer_date_is_author_date;
 123         int ignore_date;
 124         struct string_list exec;
 125         int allow_empty_message;
 126         int rebase_merges, rebase_cousins;
 127         char *strategy;
 128         struct string_list strategy_opts;
 129         struct strbuf git_format_patch_opt;
 130         int reschedule_failed_exec;
 131         int reapply_cherry_picks;
 132         int fork_point;
 133         int update_refs;
 134         int config_autosquash;
 135         int config_rebase_merges;
 136         int config_update_refs;
 137 };
 138
 139 #define REBASE_OPTIONS_INIT {                           \
 140                 .type = REBASE_UNSPECIFIED,             \
 141                 .empty = EMPTY_UNSPECIFIED,             \
 142                 .keep_empty = 1,                        \
 143                 .default_backend = "merge",             \
 144                 .flags = REBASE_NO_QUIET,               \
 145                 .git_am_opts = STRVEC_INIT,             \
 146                 .exec = STRING_LIST_INIT_NODUP,         \
 147                 .git_format_patch_opt = STRBUF_INIT,    \
 148                 .fork_point = -1,                       \
 149                 .reapply_cherry_picks = -1,             \
 150                 .allow_empty_message = 1,               \
 151                 .autosquash = -1,                       \
 152                 .rebase_merges = -1,                    \
 153                 .config_rebase_merges = -1,             \
 154                 .update_refs = -1,                      \
 155                 .config_update_refs = -1,               \
 156                 .strategy_opts = STRING_LIST_INIT_NODUP,\
 157         }
 158
 159 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 160 {
 161         struct replay_opts replay = REPLAY_OPTS_INIT;
 162
 163         replay.action = REPLAY_INTERACTIVE_REBASE;
 164         replay.strategy = NULL;
 165         sequencer_init_config(&replay);
 166
 167         replay.signoff = opts->signoff;
 168         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 169         if (opts->allow_rerere_autoupdate)
 170                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 171         replay.allow_empty = 1;
 172         replay.allow_empty_message = opts->allow_empty_message;
 173         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
 174         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
 175         replay.quiet = !(opts->flags & REBASE_NO_QUIET);
 176         replay.verbose = opts->flags & REBASE_VERBOSE;
 177         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 178         replay.committer_date_is_author_date =
 179                                         opts->committer_date_is_author_date;
 180         replay.ignore_date = opts->ignore_date;
 181         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 182         replay.reflog_action = xstrdup(opts->reflog_action);
 183         if (opts->strategy)
 184                 replay.strategy = xstrdup_or_null(opts->strategy);
 185         else if (!replay.strategy && replay.default_strategy) {
 186                 replay.strategy = replay.default_strategy;
 187                 replay.default_strategy = NULL;
 188         }
 189
 190         for (size_t i = 0; i < opts->strategy_opts.nr; i++)
 191                 strvec_push(&replay.xopts, opts->strategy_opts.items[i].string);
 192
 193         if (opts->squash_onto) {
 194                 oidcpy(&replay.squash_onto, opts->squash_onto);
 195                 replay.have_squash_onto = 1;
 196         }
 197
 198         return replay;
 199 }
 200
 201 static int edit_todo_file(unsigned flags)
 202 {
 203         const char *todo_file = rebase_path_todo();
 204         struct todo_list todo_list = TODO_LIST_INIT,
 205                 new_todo = TODO_LIST_INIT;
 206         int res = 0;
 207
 208         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 209                 return error_errno(_("could not read '%s'."), todo_file);
 210
 211         strbuf_stripspace(&todo_list.buf, comment_line_char);
 212         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 213         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 214                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 215                 res = error_errno(_("could not write '%s'"), todo_file);
 216
 217         todo_list_release(&todo_list);
 218         todo_list_release(&new_todo);
 219
 220         return res;
 221 }
 222
 223 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 224                                struct object_id *orig_head, char **revisions,
 225                                char **shortrevisions)
 226 {
 227         struct commit *base_rev = upstream ? upstream : onto;
 228         const char *shorthead;
 229
 230         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 231                              oid_to_hex(orig_head));
 232
 233         shorthead = repo_find_unique_abbrev(the_repository, orig_head,
 234                                             DEFAULT_ABBREV);
 235
 236         if (upstream) {
 237                 const char *shortrev;
 238
 239                 shortrev = repo_find_unique_abbrev(the_repository,
 240                                                    &base_rev->object.oid,
 241                                                    DEFAULT_ABBREV);
 242
 243                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 244         } else
 245                 *shortrevisions = xstrdup(shorthead);
 246
 247         return 0;
 248 }
 249
 250 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 251                             struct commit *onto,
 252                             const struct object_id *orig_head)
 253 {
 254         FILE *interactive;
 255
 256         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 257                 return error_errno(_("could not create temporary %s"), merge_dir());
 258
 259         delete_reflog("REBASE_HEAD");
 260
 261         interactive = fopen(path_interactive(), "w");
 262         if (!interactive)
 263                 return error_errno(_("could not mark as interactive"));
 264         fclose(interactive);
 265
 266         return write_basic_state(opts, head_name, onto, orig_head);
 267 }
 268
 269 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 270 {
 271         int ret = -1;
 272         char *revisions = NULL, *shortrevisions = NULL;
 273         struct strvec make_script_args = STRVEC_INIT;
 274         struct todo_list todo_list = TODO_LIST_INIT;
 275         struct replay_opts replay = get_replay_opts(opts);
 276
 277         if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head->object.oid,
 278                                 &revisions, &shortrevisions))
 279                 goto cleanup;
 280
 281         if (init_basic_state(&replay,
 282                              opts->head_name ? opts->head_name : "detached HEAD",
 283                              opts->onto, &opts->orig_head->object.oid))
 284                 goto cleanup;
 285
 286         if (!opts->upstream && opts->squash_onto)
 287                 write_file(path_squash_onto(), "%s\n",
 288                            oid_to_hex(opts->squash_onto));
 289
 290         strvec_pushl(&make_script_args, "", revisions, NULL);
 291         if (opts->restrict_revision)
 292                 strvec_pushf(&make_script_args, "^%s",
 293                              oid_to_hex(&opts->restrict_revision->object.oid));
 294
 295         ret = sequencer_make_script(the_repository, &todo_list.buf,
 296                                     make_script_args.nr, make_script_args.v,
 297                                     flags);
 298
 299         if (ret)
 300                 error(_("could not generate todo list"));
 301         else {
 302                 discard_index(&the_index);
 303                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 304                                                 &todo_list))
 305                         BUG("unusable todo list");
 306
 307                 ret = complete_action(the_repository, &replay, flags,
 308                         shortrevisions, opts->onto_name, opts->onto,
 309                         &opts->orig_head->object.oid, &opts->exec,
 310                         opts->autosquash, opts->update_refs, &todo_list);
 311         }
 312
 313 cleanup:
 314         replay_opts_release(&replay);
 315         free(revisions);
 316         free(shortrevisions);
 317         todo_list_release(&todo_list);
 318         strvec_clear(&make_script_args);
 319
 320         return ret;
 321 }
 322
 323 static int run_sequencer_rebase(struct rebase_options *opts)
 324 {
 325         unsigned flags = 0;
 326         int abbreviate_commands = 0, ret = 0;
 327
 328         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 329
 330         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 331         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 332         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 333         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 334         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 335         flags |= opts->reapply_cherry_picks ? TODO_LIST_REAPPLY_CHERRY_PICKS : 0;
 336         flags |= opts->flags & REBASE_NO_QUIET ? TODO_LIST_WARN_SKIPPED_CHERRY_PICKS : 0;
 337
 338         switch (opts->action) {
 339         case ACTION_NONE: {
 340                 if (!opts->onto && !opts->upstream)
 341                         die(_("a base commit must be provided with --upstream or --onto"));
 342
 343                 ret = do_interactive_rebase(opts, flags);
 344                 break;
 345         }
 346         case ACTION_SKIP: {
 347                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 348
 349                 rerere_clear(the_repository, &merge_rr);
 350         }
 351                 /* fallthrough */
 352         case ACTION_CONTINUE: {
 353                 struct replay_opts replay_opts = get_replay_opts(opts);
 354
 355                 ret = sequencer_continue(the_repository, &replay_opts);
 356                 replay_opts_release(&replay_opts);
 357                 break;
 358         }
 359         case ACTION_EDIT_TODO:
 360                 ret = edit_todo_file(flags);
 361                 break;
 362         case ACTION_SHOW_CURRENT_PATCH: {
 363                 struct child_process cmd = CHILD_PROCESS_INIT;
 364
 365                 cmd.git_cmd = 1;
 366                 strvec_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 367                 ret = run_command(&cmd);
 368
 369                 break;
 370         }
 371         default:
 372                 BUG("invalid command '%d'", opts->action);
 373         }
 374
 375         return ret;
 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         strbuf_release(&buf);
 486
 487         return 0;
 488 }
 489
 490 static int rebase_write_basic_state(struct rebase_options *opts)
 491 {
 492         write_file(state_dir_path("head-name", opts), "%s",
 493                    opts->head_name ? opts->head_name : "detached HEAD");
 494         write_file(state_dir_path("onto", opts), "%s",
 495                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 496         write_file(state_dir_path("orig-head", opts), "%s",
 497                    oid_to_hex(&opts->orig_head->object.oid));
 498         if (!(opts->flags & REBASE_NO_QUIET))
 499                 write_file(state_dir_path("quiet", opts), "%s", "");
 500         if (opts->flags & REBASE_VERBOSE)
 501                 write_file(state_dir_path("verbose", opts), "%s", "");
 502         if (opts->allow_rerere_autoupdate > 0)
 503                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 504                            "-%s-rerere-autoupdate",
 505                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 506                                 "" : "-no");
 507         if (opts->gpg_sign_opt)
 508                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 509                            opts->gpg_sign_opt);
 510         if (opts->signoff)
 511                 write_file(state_dir_path("signoff", opts), "--signoff");
 512
 513         return 0;
 514 }
 515
 516 static int finish_rebase(struct rebase_options *opts)
 517 {
 518         struct strbuf dir = STRBUF_INIT;
 519         int ret = 0;
 520
 521         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 522         unlink(git_path_auto_merge(the_repository));
 523         apply_autostash(state_dir_path("autostash", opts));
 524         /*
 525          * We ignore errors in 'git maintenance run --auto', since the
 526          * user should see them.
 527          */
 528         run_auto_maintenance(!(opts->flags & (REBASE_NO_QUIET|REBASE_VERBOSE)));
 529         if (opts->type == REBASE_MERGE) {
 530                 struct replay_opts replay = REPLAY_OPTS_INIT;
 531
 532                 replay.action = REPLAY_INTERACTIVE_REBASE;
 533                 ret = sequencer_remove_state(&replay);
 534                 replay_opts_release(&replay);
 535         } else {
 536                 strbuf_addstr(&dir, opts->state_dir);
 537                 if (remove_dir_recursively(&dir, 0))
 538                         ret = error(_("could not remove '%s'"),
 539                                     opts->state_dir);
 540                 strbuf_release(&dir);
 541         }
 542
 543         return ret;
 544 }
 545
 546 static int move_to_original_branch(struct rebase_options *opts)
 547 {
 548         struct strbuf branch_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 549         struct reset_head_opts ropts = { 0 };
 550         int ret;
 551
 552         if (!opts->head_name)
 553                 return 0; /* nothing to move back to */
 554
 555         if (!opts->onto)
 556                 BUG("move_to_original_branch without onto");
 557
 558         strbuf_addf(&branch_reflog, "%s (finish): %s onto %s",
 559                     opts->reflog_action,
 560                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 561         strbuf_addf(&head_reflog, "%s (finish): returning to %s",
 562                     opts->reflog_action, opts->head_name);
 563         ropts.branch = opts->head_name;
 564         ropts.flags = RESET_HEAD_REFS_ONLY;
 565         ropts.branch_msg = branch_reflog.buf;
 566         ropts.head_msg = head_reflog.buf;
 567         ret = reset_head(the_repository, &ropts);
 568
 569         strbuf_release(&branch_reflog);
 570         strbuf_release(&head_reflog);
 571         return ret;
 572 }
 573
 574 static const char *resolvemsg =
 575 N_("Resolve all conflicts manually, mark them as resolved with\n"
 576 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 577 "You can instead skip this commit: run \"git rebase --skip\".\n"
 578 "To abort and get back to the state before \"git rebase\", run "
 579 "\"git rebase --abort\".");
 580
 581 static int run_am(struct rebase_options *opts)
 582 {
 583         struct child_process am = CHILD_PROCESS_INIT;
 584         struct child_process format_patch = CHILD_PROCESS_INIT;
 585         struct strbuf revisions = STRBUF_INIT;
 586         int status;
 587         char *rebased_patches;
 588
 589         am.git_cmd = 1;
 590         strvec_push(&am.args, "am");
 591         strvec_pushf(&am.env, GIT_REFLOG_ACTION_ENVIRONMENT "=%s (pick)",
 592                      opts->reflog_action);
 593         if (opts->action == ACTION_CONTINUE) {
 594                 strvec_push(&am.args, "--resolved");
 595                 strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 596                 if (opts->gpg_sign_opt)
 597                         strvec_push(&am.args, opts->gpg_sign_opt);
 598                 status = run_command(&am);
 599                 if (status)
 600                         return status;
 601
 602                 return move_to_original_branch(opts);
 603         }
 604         if (opts->action == ACTION_SKIP) {
 605                 strvec_push(&am.args, "--skip");
 606                 strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 607                 status = run_command(&am);
 608                 if (status)
 609                         return status;
 610
 611                 return move_to_original_branch(opts);
 612         }
 613         if (opts->action == ACTION_SHOW_CURRENT_PATCH) {
 614                 strvec_push(&am.args, "--show-current-patch");
 615                 return run_command(&am);
 616         }
 617
 618         strbuf_addf(&revisions, "%s...%s",
 619                     oid_to_hex(opts->root ?
 620                                /* this is now equivalent to !opts->upstream */
 621                                &opts->onto->object.oid :
 622                                &opts->upstream->object.oid),
 623                     oid_to_hex(&opts->orig_head->object.oid));
 624
 625         rebased_patches = xstrdup(git_path("rebased-patches"));
 626         format_patch.out = open(rebased_patches,
 627                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
 628         if (format_patch.out < 0) {
 629                 status = error_errno(_("could not open '%s' for writing"),
 630                                      rebased_patches);
 631                 free(rebased_patches);
 632                 strvec_clear(&am.args);
 633                 return status;
 634         }
 635
 636         format_patch.git_cmd = 1;
 637         strvec_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
 638                      "--full-index", "--cherry-pick", "--right-only",
 639                      "--default-prefix", "--no-renames",
 640                      "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
 641                      "--no-base", NULL);
 642         if (opts->git_format_patch_opt.len)
 643                 strvec_split(&format_patch.args,
 644                              opts->git_format_patch_opt.buf);
 645         strvec_push(&format_patch.args, revisions.buf);
 646         if (opts->restrict_revision)
 647                 strvec_pushf(&format_patch.args, "^%s",
 648                              oid_to_hex(&opts->restrict_revision->object.oid));
 649
 650         status = run_command(&format_patch);
 651         if (status) {
 652                 struct reset_head_opts ropts = { 0 };
 653                 unlink(rebased_patches);
 654                 free(rebased_patches);
 655                 strvec_clear(&am.args);
 656
 657                 ropts.oid = &opts->orig_head->object.oid;
 658                 ropts.branch = opts->head_name;
 659                 ropts.default_reflog_action = opts->reflog_action;
 660                 reset_head(the_repository, &ropts);
 661                 error(_("\ngit encountered an error while preparing the "
 662                         "patches to replay\n"
 663                         "these revisions:\n"
 664                         "\n    %s\n\n"
 665                         "As a result, git cannot rebase them."),
 666                       opts->revisions);
 667
 668                 strbuf_release(&revisions);
 669                 return status;
 670         }
 671         strbuf_release(&revisions);
 672
 673         am.in = open(rebased_patches, O_RDONLY);
 674         if (am.in < 0) {
 675                 status = error_errno(_("could not open '%s' for reading"),
 676                                      rebased_patches);
 677                 free(rebased_patches);
 678                 strvec_clear(&am.args);
 679                 return status;
 680         }
 681
 682         strvec_pushv(&am.args, opts->git_am_opts.v);
 683         strvec_push(&am.args, "--rebasing");
 684         strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 685         strvec_push(&am.args, "--patch-format=mboxrd");
 686         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
 687                 strvec_push(&am.args, "--rerere-autoupdate");
 688         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
 689                 strvec_push(&am.args, "--no-rerere-autoupdate");
 690         if (opts->gpg_sign_opt)
 691                 strvec_push(&am.args, opts->gpg_sign_opt);
 692         status = run_command(&am);
 693         unlink(rebased_patches);
 694         free(rebased_patches);
 695
 696         if (!status) {
 697                 return move_to_original_branch(opts);
 698         }
 699
 700         if (is_directory(opts->state_dir))
 701                 rebase_write_basic_state(opts);
 702
 703         return status;
 704 }
 705
 706 static int run_specific_rebase(struct rebase_options *opts)
 707 {
 708         int status;
 709
 710         if (opts->type == REBASE_MERGE) {
 711                 /* Run sequencer-based rebase */
 712                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
 713                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT))
 714                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
 715                 if (opts->gpg_sign_opt) {
 716                         /* remove the leading "-S" */
 717                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
 718                         free(opts->gpg_sign_opt);
 719                         opts->gpg_sign_opt = tmp;
 720                 }
 721
 722                 status = run_sequencer_rebase(opts);
 723         } else if (opts->type == REBASE_APPLY)
 724                 status = run_am(opts);
 725         else
 726                 BUG("Unhandled rebase type %d", opts->type);
 727
 728         if (opts->dont_finish_rebase)
 729                 ; /* do nothing */
 730         else if (opts->type == REBASE_MERGE)
 731                 ; /* merge backend cleans up after itself */
 732         else if (status == 0) {
 733                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 734                         finish_rebase(opts);
 735         } else if (status == 2) {
 736                 struct strbuf dir = STRBUF_INIT;
 737
 738                 apply_autostash(state_dir_path("autostash", opts));
 739                 strbuf_addstr(&dir, opts->state_dir);
 740                 remove_dir_recursively(&dir, 0);
 741                 strbuf_release(&dir);
 742                 die("Nothing to do");
 743         }
 744
 745         return status ? -1 : 0;
 746 }
 747
 748 static void parse_rebase_merges_value(struct rebase_options *options, const char *value)
 749 {
 750         if (!strcmp("no-rebase-cousins", value))
 751                 options->rebase_cousins = 0;
 752         else if (!strcmp("rebase-cousins", value))
 753                 options->rebase_cousins = 1;
 754         else
 755                 die(_("Unknown rebase-merges mode: %s"), value);
 756 }
 757
 758 static int rebase_config(const char *var, const char *value,
 759                          const struct config_context *ctx, void *data)
 760 {
 761         struct rebase_options *opts = data;
 762
 763         if (!strcmp(var, "rebase.stat")) {
 764                 if (git_config_bool(var, value))
 765                         opts->flags |= REBASE_DIFFSTAT;
 766                 else
 767                         opts->flags &= ~REBASE_DIFFSTAT;
 768                 return 0;
 769         }
 770
 771         if (!strcmp(var, "rebase.autosquash")) {
 772                 opts->config_autosquash = git_config_bool(var, value);
 773                 return 0;
 774         }
 775
 776         if (!strcmp(var, "commit.gpgsign")) {
 777                 free(opts->gpg_sign_opt);
 778                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 779                         xstrdup("-S") : NULL;
 780                 return 0;
 781         }
 782
 783         if (!strcmp(var, "rebase.autostash")) {
 784                 opts->autostash = git_config_bool(var, value);
 785                 return 0;
 786         }
 787
 788         if (!strcmp(var, "rebase.rebasemerges")) {
 789                 opts->config_rebase_merges = git_parse_maybe_bool(value);
 790                 if (opts->config_rebase_merges < 0) {
 791                         opts->config_rebase_merges = 1;
 792                         parse_rebase_merges_value(opts, value);
 793                 } else {
 794                         opts->rebase_cousins = 0;
 795                 }
 796                 return 0;
 797         }
 798
 799         if (!strcmp(var, "rebase.updaterefs")) {
 800                 opts->config_update_refs = git_config_bool(var, value);
 801                 return 0;
 802         }
 803
 804         if (!strcmp(var, "rebase.reschedulefailedexec")) {
 805                 opts->reschedule_failed_exec = git_config_bool(var, value);
 806                 return 0;
 807         }
 808
 809         if (!strcmp(var, "rebase.forkpoint")) {
 810                 opts->fork_point = git_config_bool(var, value) ? -1 : 0;
 811                 return 0;
 812         }
 813
 814         if (!strcmp(var, "rebase.backend")) {
 815                 return git_config_string(&opts->default_backend, var, value);
 816         }
 817
 818         return git_default_config(var, value, ctx, data);
 819 }
 820
 821 static int checkout_up_to_date(struct rebase_options *options)
 822 {
 823         struct strbuf buf = STRBUF_INIT;
 824         struct reset_head_opts ropts = { 0 };
 825         int ret = 0;
 826
 827         strbuf_addf(&buf, "%s: checkout %s",
 828                     options->reflog_action, options->switch_to);
 829         ropts.oid = &options->orig_head->object.oid;
 830         ropts.branch = options->head_name;
 831         ropts.flags = RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 832         if (!ropts.branch)
 833                 ropts.flags |=  RESET_HEAD_DETACH;
 834         ropts.head_msg = buf.buf;
 835         if (reset_head(the_repository, &ropts) < 0)
 836                 ret = error(_("could not switch to %s"), options->switch_to);
 837         strbuf_release(&buf);
 838
 839         return ret;
 840 }
 841
 842 /*
 843  * Determines whether the commits in from..to are linear, i.e. contain
 844  * no merge commits. This function *expects* `from` to be an ancestor of
 845  * `to`.
 846  */
 847 static int is_linear_history(struct commit *from, struct commit *to)
 848 {
 849         while (to && to != from) {
 850                 repo_parse_commit(the_repository, to);
 851                 if (!to->parents)
 852                         return 1;
 853                 if (to->parents->next)
 854                         return 0;
 855                 to = to->parents->item;
 856         }
 857         return 1;
 858 }
 859
 860 static int can_fast_forward(struct commit *onto, struct commit *upstream,
 861                             struct commit *restrict_revision,
 862                             struct commit *head, struct object_id *branch_base)
 863 {
 864         struct commit_list *merge_bases = NULL;
 865         int res = 0;
 866
 867         if (is_null_oid(branch_base))
 868                 goto done; /* fill_branch_base() found multiple merge bases */
 869
 870         if (!oideq(branch_base, &onto->object.oid))
 871                 goto done;
 872
 873         if (restrict_revision && !oideq(&restrict_revision->object.oid, branch_base))
 874                 goto done;
 875
 876         if (!upstream)
 877                 goto done;
 878
 879         merge_bases = repo_get_merge_bases(the_repository, upstream, head);
 880         if (!merge_bases || merge_bases->next)
 881                 goto done;
 882
 883         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
 884                 goto done;
 885
 886         res = 1;
 887
 888 done:
 889         free_commit_list(merge_bases);
 890         return res && is_linear_history(onto, head);
 891 }
 892
 893 static void fill_branch_base(struct rebase_options *options,
 894                             struct object_id *branch_base)
 895 {
 896         struct commit_list *merge_bases = NULL;
 897
 898         merge_bases = repo_get_merge_bases(the_repository, options->onto,
 899                                            options->orig_head);
 900         if (!merge_bases || merge_bases->next)
 901                 oidcpy(branch_base, null_oid());
 902         else
 903                 oidcpy(branch_base, &merge_bases->item->object.oid);
 904
 905         free_commit_list(merge_bases);
 906 }
 907
 908 static int parse_opt_am(const struct option *opt, const char *arg, int unset)
 909 {
 910         struct rebase_options *opts = opt->value;
 911
 912         BUG_ON_OPT_NEG(unset);
 913         BUG_ON_OPT_ARG(arg);
 914
 915         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_APPLY)
 916             die(_("apply options and merge options cannot be used together"));
 917
 918         opts->type = REBASE_APPLY;
 919
 920         return 0;
 921 }
 922
 923 /* -i followed by -m is still -i */
 924 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 925 {
 926         struct rebase_options *opts = opt->value;
 927
 928         BUG_ON_OPT_NEG(unset);
 929         BUG_ON_OPT_ARG(arg);
 930
 931         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_MERGE)
 932             die(_("apply options and merge options cannot be used together"));
 933
 934         opts->type = REBASE_MERGE;
 935
 936         return 0;
 937 }
 938
 939 /* -i followed by -r is still explicitly interactive, but -r alone is not */
 940 static int parse_opt_interactive(const struct option *opt, const char *arg,
 941                                  int unset)
 942 {
 943         struct rebase_options *opts = opt->value;
 944
 945         BUG_ON_OPT_NEG(unset);
 946         BUG_ON_OPT_ARG(arg);
 947
 948         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_MERGE)
 949             die(_("apply options and merge options cannot be used together"));
 950
 951         opts->type = REBASE_MERGE;
 952         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 953
 954         return 0;
 955 }
 956
 957 static enum empty_type parse_empty_value(const char *value)
 958 {
 959         if (!strcasecmp(value, "drop"))
 960                 return EMPTY_DROP;
 961         else if (!strcasecmp(value, "keep"))
 962                 return EMPTY_KEEP;
 963         else if (!strcasecmp(value, "ask"))
 964                 return EMPTY_ASK;
 965
 966         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
 967 }
 968
 969 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 970                                 int unset)
 971 {
 972         struct rebase_options *opts = opt->value;
 973
 974         BUG_ON_OPT_ARG(arg);
 975
 976         imply_merge(opts, unset ? "--no-keep-empty" : "--keep-empty");
 977         opts->keep_empty = !unset;
 978         return 0;
 979 }
 980
 981 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
 982 {
 983         struct rebase_options *options = opt->value;
 984         enum empty_type value = parse_empty_value(arg);
 985
 986         BUG_ON_OPT_NEG(unset);
 987
 988         options->empty = value;
 989         return 0;
 990 }
 991
 992 static int parse_opt_rebase_merges(const struct option *opt, const char *arg, int unset)
 993 {
 994         struct rebase_options *options = opt->value;
 995
 996         options->rebase_merges = !unset;
 997         options->rebase_cousins = 0;
 998
 999         if (arg) {
1000                 if (!*arg) {
1001                         warning(_("--rebase-merges with an empty string "
1002                                   "argument is deprecated and will stop "
1003                                   "working in a future version of Git. Use "
1004                                   "--rebase-merges without an argument "
1005                                   "instead, which does the same thing."));
1006                         return 0;
1007                 }
1008                 parse_rebase_merges_value(options, arg);
1009         }
1010
1011         return 0;
1012 }
1013
1014 static void NORETURN error_on_missing_default_upstream(void)
1015 {
1016         struct branch *current_branch = branch_get(NULL);
1017
1018         printf(_("%s\n"
1019                  "Please specify which branch you want to rebase against.\n"
1020                  "See git-rebase(1) for details.\n"
1021                  "\n"
1022                  "    git rebase '<branch>'\n"
1023                  "\n"),
1024                 current_branch ? _("There is no tracking information for "
1025                         "the current branch.") :
1026                         _("You are not currently on a branch."));
1027
1028         if (current_branch) {
1029                 const char *remote = current_branch->remote_name;
1030
1031                 if (!remote)
1032                         remote = _("<remote>");
1033
1034                 printf(_("If you wish to set tracking information for this "
1035                          "branch you can do so with:\n"
1036                          "\n"
1037                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1038                          "\n"),
1039                        remote, current_branch->name);
1040         }
1041         exit(1);
1042 }
1043
1044 static int check_exec_cmd(const char *cmd)
1045 {
1046         if (strchr(cmd, '\n'))
1047                 return error(_("exec commands cannot contain newlines"));
1048
1049         /* Does the command consist purely of whitespace? */
1050         if (!cmd[strspn(cmd, " \t\r\f\v")])
1051                 return error(_("empty exec command"));
1052
1053         return 0;
1054 }
1055
1056 int cmd_rebase(int argc, const char **argv, const char *prefix)
1057 {
1058         struct rebase_options options = REBASE_OPTIONS_INIT;
1059         const char *branch_name;
1060         int ret, flags, total_argc, in_progress = 0;
1061         int keep_base = 0;
1062         int ok_to_skip_pre_rebase = 0;
1063         struct strbuf msg = STRBUF_INIT;
1064         struct strbuf revisions = STRBUF_INIT;
1065         struct strbuf buf = STRBUF_INIT;
1066         struct object_id branch_base;
1067         int ignore_whitespace = 0;
1068         const char *gpg_sign = NULL;
1069         struct object_id squash_onto;
1070         char *squash_onto_name = NULL;
1071         char *keep_base_onto_name = NULL;
1072         int reschedule_failed_exec = -1;
1073         int allow_preemptive_ff = 1;
1074         int preserve_merges_selected = 0;
1075         struct reset_head_opts ropts = { 0 };
1076         struct option builtin_rebase_options[] = {
1077                 OPT_STRING(0, "onto", &options.onto_name,
1078                            N_("revision"),
1079                            N_("rebase onto given branch instead of upstream")),
1080                 OPT_BOOL(0, "keep-base", &keep_base,
1081                          N_("use the merge-base of upstream and branch as the current base")),
1082                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1083                          N_("allow pre-rebase hook to run")),
1084                 OPT_NEGBIT('q', "quiet", &options.flags,
1085                            N_("be quiet. implies --no-stat"),
1086                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1087                 OPT_BIT('v', "verbose", &options.flags,
1088                         N_("display a diffstat of what changed upstream"),
1089                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1090                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1091                         N_("do not show diffstat of what changed upstream"),
1092                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1093                 OPT_BOOL(0, "signoff", &options.signoff,
1094                          N_("add a Signed-off-by trailer to each commit")),
1095                 OPT_BOOL(0, "committer-date-is-author-date",
1096                          &options.committer_date_is_author_date,
1097                          N_("make committer date match author date")),
1098                 OPT_BOOL(0, "reset-author-date", &options.ignore_date,
1099                          N_("ignore author date and use current date")),
1100                 OPT_HIDDEN_BOOL(0, "ignore-date", &options.ignore_date,
1101                                 N_("synonym of --reset-author-date")),
1102                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1103                                   N_("passed to 'git apply'"), 0),
1104                 OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
1105                          N_("ignore changes in whitespace")),
1106                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1107                                   N_("action"), N_("passed to 'git apply'"), 0),
1108                 OPT_BIT('f', "force-rebase", &options.flags,
1109                         N_("cherry-pick all commits, even if unchanged"),
1110                         REBASE_FORCE),
1111                 OPT_BIT(0, "no-ff", &options.flags,
1112                         N_("cherry-pick all commits, even if unchanged"),
1113                         REBASE_FORCE),
1114                 OPT_CMDMODE(0, "continue", &options.action, N_("continue"),
1115                             ACTION_CONTINUE),
1116                 OPT_CMDMODE(0, "skip", &options.action,
1117                             N_("skip current patch and continue"), ACTION_SKIP),
1118                 OPT_CMDMODE(0, "abort", &options.action,
1119                             N_("abort and check out the original branch"),
1120                             ACTION_ABORT),
1121                 OPT_CMDMODE(0, "quit", &options.action,
1122                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1123                 OPT_CMDMODE(0, "edit-todo", &options.action, N_("edit the todo list "
1124                             "during an interactive rebase"), ACTION_EDIT_TODO),
1125                 OPT_CMDMODE(0, "show-current-patch", &options.action,
1126                             N_("show the patch file being applied or merged"),
1127                             ACTION_SHOW_CURRENT_PATCH),
1128                 OPT_CALLBACK_F(0, "apply", &options, NULL,
1129                         N_("use apply strategies to rebase"),
1130                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1131                         parse_opt_am),
1132                 OPT_CALLBACK_F('m', "merge", &options, NULL,
1133                         N_("use merging strategies to rebase"),
1134                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1135                         parse_opt_merge),
1136                 OPT_CALLBACK_F('i', "interactive", &options, NULL,
1137                         N_("let the user edit the list of commits to rebase"),
1138                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1139                         parse_opt_interactive),
1140                 OPT_SET_INT_F('p', "preserve-merges", &preserve_merges_selected,
1141                               N_("(REMOVED) was: try to recreate merges "
1142                                  "instead of ignoring them"),
1143                               1, PARSE_OPT_HIDDEN),
1144                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1145                 OPT_CALLBACK_F(0, "empty", &options, "(drop|keep|ask)",
1146                                N_("how to handle commits that become empty"),
1147                                PARSE_OPT_NONEG, parse_opt_empty),
1148                 OPT_CALLBACK_F('k', "keep-empty", &options, NULL,
1149                         N_("keep commits which start empty"),
1150                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1151                         parse_opt_keep_empty),
1152                 OPT_BOOL(0, "autosquash", &options.autosquash,
1153                          N_("move commits that begin with "
1154                             "squash!/fixup! under -i")),
1155                 OPT_BOOL(0, "update-refs", &options.update_refs,
1156                          N_("update branches that point to commits "
1157                             "that are being rebased")),
1158                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1159                         N_("GPG-sign commits"),
1160                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1161                 OPT_AUTOSTASH(&options.autostash),
1162                 OPT_STRING_LIST('x', "exec", &options.exec, N_("exec"),
1163                                 N_("add exec lines after each commit of the "
1164                                    "editable list")),
1165                 OPT_BOOL_F(0, "allow-empty-message",
1166                            &options.allow_empty_message,
1167                            N_("allow rebasing commits with empty messages"),
1168                            PARSE_OPT_HIDDEN),
1169                 OPT_CALLBACK_F('r', "rebase-merges", &options, N_("mode"),
1170                         N_("try to rebase merges instead of skipping them"),
1171                         PARSE_OPT_OPTARG, parse_opt_rebase_merges),
1172                 OPT_BOOL(0, "fork-point", &options.fork_point,
1173                          N_("use 'merge-base --fork-point' to refine upstream")),
1174                 OPT_STRING('s', "strategy", &options.strategy,
1175                            N_("strategy"), N_("use the given merge strategy")),
1176                 OPT_STRING_LIST('X', "strategy-option", &options.strategy_opts,
1177                                 N_("option"),
1178                                 N_("pass the argument through to the merge "
1179                                    "strategy")),
1180                 OPT_BOOL(0, "root", &options.root,
1181                          N_("rebase all reachable commits up to the root(s)")),
1182                 OPT_BOOL(0, "reschedule-failed-exec",
1183                          &reschedule_failed_exec,
1184                          N_("automatically re-schedule any `exec` that fails")),
1185                 OPT_BOOL(0, "reapply-cherry-picks", &options.reapply_cherry_picks,
1186                          N_("apply all changes, even those already present upstream")),
1187                 OPT_END(),
1188         };
1189         int i;
1190
1191         if (argc == 2 && !strcmp(argv[1], "-h"))
1192                 usage_with_options(builtin_rebase_usage,
1193                                    builtin_rebase_options);
1194
1195         prepare_repo_settings(the_repository);
1196         the_repository->settings.command_requires_full_index = 0;
1197
1198         git_config(rebase_config, &options);
1199         /* options.gpg_sign_opt will be either "-S" or NULL */
1200         gpg_sign = options.gpg_sign_opt ? "" : NULL;
1201         FREE_AND_NULL(options.gpg_sign_opt);
1202
1203         strbuf_reset(&buf);
1204         strbuf_addf(&buf, "%s/applying", apply_dir());
1205         if(file_exists(buf.buf))
1206                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1207
1208         if (is_directory(apply_dir())) {
1209                 options.type = REBASE_APPLY;
1210                 options.state_dir = apply_dir();
1211         } else if (is_directory(merge_dir())) {
1212                 strbuf_reset(&buf);
1213                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1214                 if (!(options.action == ACTION_ABORT) && is_directory(buf.buf)) {
1215                         die(_("`rebase --preserve-merges` (-p) is no longer supported.\n"
1216                         "Use `git rebase --abort` to terminate current rebase.\n"
1217                         "Or downgrade to v2.33, or earlier, to complete the rebase."));
1218                 } else {
1219                         strbuf_reset(&buf);
1220                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1221                         options.type = REBASE_MERGE;
1222                         if (file_exists(buf.buf))
1223                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1224                 }
1225                 options.state_dir = merge_dir();
1226         }
1227
1228         if (options.type != REBASE_UNSPECIFIED)
1229                 in_progress = 1;
1230
1231         total_argc = argc;
1232         argc = parse_options(argc, argv, prefix,
1233                              builtin_rebase_options,
1234                              builtin_rebase_usage, 0);
1235
1236         if (preserve_merges_selected)
1237                 die(_("--preserve-merges was replaced by --rebase-merges\n"
1238                         "Note: Your `pull.rebase` configuration may also be set to 'preserve',\n"
1239                         "which is no longer supported; use 'merges' instead"));
1240
1241         if (options.action != ACTION_NONE && total_argc != 2) {
1242                 usage_with_options(builtin_rebase_usage,
1243                                    builtin_rebase_options);
1244         }
1245
1246         if (argc > 2)
1247                 usage_with_options(builtin_rebase_usage,
1248                                    builtin_rebase_options);
1249
1250         if (keep_base) {
1251                 if (options.onto_name)
1252                         die(_("options '%s' and '%s' cannot be used together"), "--keep-base", "--onto");
1253                 if (options.root)
1254                         die(_("options '%s' and '%s' cannot be used together"), "--keep-base", "--root");
1255                 /*
1256                  * --keep-base defaults to --no-fork-point to keep the
1257                  * base the same.
1258                  */
1259                 if (options.fork_point < 0)
1260                         options.fork_point = 0;
1261         }
1262         if (options.root && options.fork_point > 0)
1263                 die(_("options '%s' and '%s' cannot be used together"), "--root", "--fork-point");
1264
1265         if (options.action != ACTION_NONE && !in_progress)
1266                 die(_("No rebase in progress?"));
1267
1268         if (options.action == ACTION_EDIT_TODO && !is_merge(&options))
1269                 die(_("The --edit-todo action can only be used during "
1270                       "interactive rebase."));
1271
1272         if (trace2_is_enabled()) {
1273                 if (is_merge(&options))
1274                         trace2_cmd_mode("interactive");
1275                 else if (options.exec.nr)
1276                         trace2_cmd_mode("interactive-exec");
1277                 else
1278                         trace2_cmd_mode(action_names[options.action]);
1279         }
1280
1281         options.reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1282         options.reflog_action =
1283                 xstrdup(options.reflog_action ? options.reflog_action : "rebase");
1284
1285         switch (options.action) {
1286         case ACTION_CONTINUE: {
1287                 struct object_id head;
1288                 struct lock_file lock_file = LOCK_INIT;
1289                 int fd;
1290
1291                 /* Sanity check */
1292                 if (repo_get_oid(the_repository, "HEAD", &head))
1293                         die(_("Cannot read HEAD"));
1294
1295                 fd = repo_hold_locked_index(the_repository, &lock_file, 0);
1296                 if (repo_read_index(the_repository) < 0)
1297                         die(_("could not read index"));
1298                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1299                               NULL);
1300                 if (0 <= fd)
1301                         repo_update_index_if_able(the_repository, &lock_file);
1302                 rollback_lock_file(&lock_file);
1303
1304                 if (has_unstaged_changes(the_repository, 1)) {
1305                         puts(_("You must edit all merge conflicts and then\n"
1306                                "mark them as resolved using git add"));
1307                         exit(1);
1308                 }
1309                 if (read_basic_state(&options))
1310                         exit(1);
1311                 goto run_rebase;
1312         }
1313         case ACTION_SKIP: {
1314                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1315
1316                 rerere_clear(the_repository, &merge_rr);
1317                 string_list_clear(&merge_rr, 1);
1318                 ropts.flags = RESET_HEAD_HARD;
1319                 if (reset_head(the_repository, &ropts) < 0)
1320                         die(_("could not discard worktree changes"));
1321                 remove_branch_state(the_repository, 0);
1322                 if (read_basic_state(&options))
1323                         exit(1);
1324                 goto run_rebase;
1325         }
1326         case ACTION_ABORT: {
1327                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1328                 struct strbuf head_msg = STRBUF_INIT;
1329
1330                 rerere_clear(the_repository, &merge_rr);
1331                 string_list_clear(&merge_rr, 1);
1332
1333                 if (read_basic_state(&options))
1334                         exit(1);
1335
1336                 strbuf_addf(&head_msg, "%s (abort): returning to %s",
1337                             options.reflog_action,
1338                             options.head_name ? options.head_name
1339                                               : oid_to_hex(&options.orig_head->object.oid));
1340                 ropts.oid = &options.orig_head->object.oid;
1341                 ropts.head_msg = head_msg.buf;
1342                 ropts.branch = options.head_name;
1343                 ropts.flags = RESET_HEAD_HARD;
1344                 if (reset_head(the_repository, &ropts) < 0)
1345                         die(_("could not move back to %s"),
1346                             oid_to_hex(&options.orig_head->object.oid));
1347                 strbuf_release(&head_msg);
1348                 remove_branch_state(the_repository, 0);
1349                 ret = finish_rebase(&options);
1350                 goto cleanup;
1351         }
1352         case ACTION_QUIT: {
1353                 save_autostash(state_dir_path("autostash", &options));
1354                 if (options.type == REBASE_MERGE) {
1355                         struct replay_opts replay = REPLAY_OPTS_INIT;
1356
1357                         replay.action = REPLAY_INTERACTIVE_REBASE;
1358                         ret = sequencer_remove_state(&replay);
1359                         replay_opts_release(&replay);
1360                 } else {
1361                         strbuf_reset(&buf);
1362                         strbuf_addstr(&buf, options.state_dir);
1363                         ret = remove_dir_recursively(&buf, 0);
1364                         if (ret)
1365                                 error(_("could not remove '%s'"),
1366                                        options.state_dir);
1367                 }
1368                 goto cleanup;
1369         }
1370         case ACTION_EDIT_TODO:
1371                 options.dont_finish_rebase = 1;
1372                 goto run_rebase;
1373         case ACTION_SHOW_CURRENT_PATCH:
1374                 options.dont_finish_rebase = 1;
1375                 goto run_rebase;
1376         case ACTION_NONE:
1377                 break;
1378         default:
1379                 BUG("action: %d", options.action);
1380         }
1381
1382         /* Make sure no rebase is in progress */
1383         if (in_progress) {
1384                 const char *last_slash = strrchr(options.state_dir, '/');
1385                 const char *state_dir_base =
1386                         last_slash ? last_slash + 1 : options.state_dir;
1387                 const char *cmd_live_rebase =
1388                         "git rebase (--continue | --abort | --skip)";
1389                 strbuf_reset(&buf);
1390                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1391                 die(_("It seems that there is already a %s directory, and\n"
1392                       "I wonder if you are in the middle of another rebase.  "
1393                       "If that is the\n"
1394                       "case, please try\n\t%s\n"
1395                       "If that is not the case, please\n\t%s\n"
1396                       "and run me again.  I am stopping in case you still "
1397                       "have something\n"
1398                       "valuable there.\n"),
1399                     state_dir_base, cmd_live_rebase, buf.buf);
1400         }
1401
1402         if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
1403             (options.action != ACTION_NONE) ||
1404             (options.exec.nr > 0) ||
1405             options.autosquash == 1) {
1406                 allow_preemptive_ff = 0;
1407         }
1408         if (options.committer_date_is_author_date || options.ignore_date)
1409                 options.flags |= REBASE_FORCE;
1410
1411         for (i = 0; i < options.git_am_opts.nr; i++) {
1412                 const char *option = options.git_am_opts.v[i], *p;
1413                 if (!strcmp(option, "--whitespace=fix") ||
1414                     !strcmp(option, "--whitespace=strip"))
1415                         allow_preemptive_ff = 0;
1416                 else if (skip_prefix(option, "-C", &p)) {
1417                         while (*p)
1418                                 if (!isdigit(*(p++)))
1419                                         die(_("switch `C' expects a "
1420                                               "numerical value"));
1421                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1422                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1423                             strcmp(p, "error") && strcmp(p, "error-all"))
1424                                 die("Invalid whitespace option: '%s'", p);
1425                 }
1426         }
1427
1428         for (i = 0; i < options.exec.nr; i++)
1429                 if (check_exec_cmd(options.exec.items[i].string))
1430                         exit(1);
1431
1432         if (!(options.flags & REBASE_NO_QUIET))
1433                 strvec_push(&options.git_am_opts, "-q");
1434
1435         if (options.empty != EMPTY_UNSPECIFIED)
1436                 imply_merge(&options, "--empty");
1437
1438         if (options.reapply_cherry_picks < 0)
1439                 /*
1440                  * We default to --no-reapply-cherry-picks unless
1441                  * --keep-base is given; when --keep-base is given, we want
1442                  * to default to --reapply-cherry-picks.
1443                  */
1444                 options.reapply_cherry_picks = keep_base;
1445         else if (!keep_base)
1446                 /*
1447                  * The apply backend always searches for and drops cherry
1448                  * picks.  This is often not wanted with --keep-base, so
1449                  * --keep-base allows --reapply-cherry-picks to be
1450                  * simulated by altering the upstream such that
1451                  * cherry-picks cannot be detected and thus all commits are
1452                  * reapplied.  Thus, --[no-]reapply-cherry-picks is
1453                  * supported when --keep-base is specified, but not when
1454                  * --keep-base is left out.
1455                  */
1456                 imply_merge(&options, options.reapply_cherry_picks ?
1457                                           "--reapply-cherry-picks" :
1458                                           "--no-reapply-cherry-picks");
1459
1460         if (gpg_sign)
1461                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1462
1463         if (options.exec.nr)
1464                 imply_merge(&options, "--exec");
1465
1466         if (options.type == REBASE_APPLY) {
1467                 if (ignore_whitespace)
1468                         strvec_push(&options.git_am_opts,
1469                                     "--ignore-whitespace");
1470                 if (options.committer_date_is_author_date)
1471                         strvec_push(&options.git_am_opts,
1472                                     "--committer-date-is-author-date");
1473                 if (options.ignore_date)
1474                         strvec_push(&options.git_am_opts, "--ignore-date");
1475         } else {
1476                 /* REBASE_MERGE */
1477                 if (ignore_whitespace) {
1478                         string_list_append(&options.strategy_opts,
1479                                            "ignore-space-change");
1480                 }
1481         }
1482
1483         if (options.strategy_opts.nr && !options.strategy)
1484                 options.strategy = "ort";
1485
1486         if (options.strategy) {
1487                 options.strategy = xstrdup(options.strategy);
1488                 imply_merge(&options, "--strategy");
1489         }
1490
1491         if (options.root && !options.onto_name)
1492                 imply_merge(&options, "--root without --onto");
1493
1494         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1495                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1496
1497         if (options.git_am_opts.nr || options.type == REBASE_APPLY) {
1498                 /* all am options except -q are compatible only with --apply */
1499                 for (i = options.git_am_opts.nr - 1; i >= 0; i--)
1500                         if (strcmp(options.git_am_opts.v[i], "-q"))
1501                                 break;
1502
1503                 if (i >= 0 || options.type == REBASE_APPLY) {
1504                         if (is_merge(&options))
1505                                 die(_("apply options and merge options "
1506                                           "cannot be used together"));
1507                         else if (options.rebase_merges == -1 && options.config_rebase_merges == 1)
1508                                 die(_("apply options are incompatible with rebase.rebaseMerges.  Consider adding --no-rebase-merges"));
1509                         else if (options.update_refs == -1 && options.config_update_refs == 1)
1510                                 die(_("apply options are incompatible with rebase.updateRefs.  Consider adding --no-update-refs"));
1511                         else
1512                                 options.type = REBASE_APPLY;
1513                 }
1514         }
1515
1516         if (options.update_refs == 1)
1517                 imply_merge(&options, "--update-refs");
1518         options.update_refs = (options.update_refs >= 0) ? options.update_refs :
1519                              ((options.config_update_refs >= 0) ? options.config_update_refs : 0);
1520
1521         if (options.rebase_merges == 1)
1522                 imply_merge(&options, "--rebase-merges");
1523         options.rebase_merges = (options.rebase_merges >= 0) ? options.rebase_merges :
1524                                 ((options.config_rebase_merges >= 0) ? options.config_rebase_merges : 0);
1525
1526         if (options.autosquash == 1) {
1527                 imply_merge(&options, "--autosquash");
1528         } else if (options.autosquash == -1) {
1529                 options.autosquash =
1530                         options.config_autosquash &&
1531                         (options.flags & REBASE_INTERACTIVE_EXPLICIT);
1532         }
1533
1534         if (options.type == REBASE_UNSPECIFIED) {
1535                 if (!strcmp(options.default_backend, "merge"))
1536                         options.type = REBASE_MERGE;
1537                 else if (!strcmp(options.default_backend, "apply"))
1538                         options.type = REBASE_APPLY;
1539                 else
1540                         die(_("Unknown rebase backend: %s"),
1541                             options.default_backend);
1542         }
1543
1544         if (options.type == REBASE_MERGE &&
1545             !options.strategy &&
1546             getenv("GIT_TEST_MERGE_ALGORITHM"))
1547                 options.strategy = xstrdup(getenv("GIT_TEST_MERGE_ALGORITHM"));
1548
1549         switch (options.type) {
1550         case REBASE_MERGE:
1551                 options.state_dir = merge_dir();
1552                 break;
1553         case REBASE_APPLY:
1554                 options.state_dir = apply_dir();
1555                 break;
1556         default:
1557                 BUG("options.type was just set above; should be unreachable.");
1558         }
1559
1560         if (options.empty == EMPTY_UNSPECIFIED) {
1561                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1562                         options.empty = EMPTY_ASK;
1563                 else if (options.exec.nr > 0)
1564                         options.empty = EMPTY_KEEP;
1565                 else
1566                         options.empty = EMPTY_DROP;
1567         }
1568         if (reschedule_failed_exec > 0 && !is_merge(&options))
1569                 die(_("--reschedule-failed-exec requires "
1570                       "--exec or --interactive"));
1571         if (reschedule_failed_exec >= 0)
1572                 options.reschedule_failed_exec = reschedule_failed_exec;
1573
1574         if (options.signoff) {
1575                 strvec_push(&options.git_am_opts, "--signoff");
1576                 options.flags |= REBASE_FORCE;
1577         }
1578
1579         if (!options.root) {
1580                 if (argc < 1) {
1581                         struct branch *branch;
1582
1583                         branch = branch_get(NULL);
1584                         options.upstream_name = branch_get_upstream(branch,
1585                                                                     NULL);
1586                         if (!options.upstream_name)
1587                                 error_on_missing_default_upstream();
1588                         if (options.fork_point < 0)
1589                                 options.fork_point = 1;
1590                 } else {
1591                         options.upstream_name = argv[0];
1592                         argc--;
1593                         argv++;
1594                         if (!strcmp(options.upstream_name, "-"))
1595                                 options.upstream_name = "@{-1}";
1596                 }
1597                 options.upstream =
1598                         lookup_commit_reference_by_name(options.upstream_name);
1599                 if (!options.upstream)
1600                         die(_("invalid upstream '%s'"), options.upstream_name);
1601                 options.upstream_arg = options.upstream_name;
1602         } else {
1603                 if (!options.onto_name) {
1604                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1605                                         &squash_onto, NULL, NULL) < 0)
1606                                 die(_("Could not create new root commit"));
1607                         options.squash_onto = &squash_onto;
1608                         options.onto_name = squash_onto_name =
1609                                 xstrdup(oid_to_hex(&squash_onto));
1610                 } else
1611                         options.root_with_onto = 1;
1612
1613                 options.upstream_name = NULL;
1614                 options.upstream = NULL;
1615                 if (argc > 1)
1616                         usage_with_options(builtin_rebase_usage,
1617                                            builtin_rebase_options);
1618                 options.upstream_arg = "--root";
1619         }
1620
1621         /*
1622          * If the branch to rebase is given, that is the branch we will rebase
1623          * branch_name -- branch/commit being rebased, or
1624          *                HEAD (already detached)
1625          * orig_head -- commit object name of tip of the branch before rebasing
1626          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1627          */
1628         if (argc == 1) {
1629                 /* Is it "rebase other branchname" or "rebase other commit"? */
1630                 struct object_id branch_oid;
1631                 branch_name = argv[0];
1632                 options.switch_to = argv[0];
1633
1634                 /* Is it a local branch? */
1635                 strbuf_reset(&buf);
1636                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1637                 if (!read_ref(buf.buf, &branch_oid)) {
1638                         die_if_checked_out(buf.buf, 1);
1639                         options.head_name = xstrdup(buf.buf);
1640                         options.orig_head =
1641                                 lookup_commit_object(the_repository,
1642                                                      &branch_oid);
1643                 /* If not is it a valid ref (branch or commit)? */
1644                 } else {
1645                         options.orig_head =
1646                                 lookup_commit_reference_by_name(branch_name);
1647                         options.head_name = NULL;
1648                 }
1649                 if (!options.orig_head)
1650                         die(_("no such branch/commit '%s'"), branch_name);
1651         } else if (argc == 0) {
1652                 /* Do not need to switch branches, we are already on it. */
1653                 options.head_name =
1654                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1655                                          &flags));
1656                 if (!options.head_name)
1657                         die(_("No such ref: %s"), "HEAD");
1658                 if (flags & REF_ISSYMREF) {
1659                         if (!skip_prefix(options.head_name,
1660                                          "refs/heads/", &branch_name))
1661                                 branch_name = options.head_name;
1662
1663                 } else {
1664                         FREE_AND_NULL(options.head_name);
1665                         branch_name = "HEAD";
1666                 }
1667                 options.orig_head = lookup_commit_reference_by_name("HEAD");
1668                 if (!options.orig_head)
1669                         die(_("Could not resolve HEAD to a commit"));
1670         } else
1671                 BUG("unexpected number of arguments left to parse");
1672
1673         /* Make sure the branch to rebase onto is valid. */
1674         if (keep_base) {
1675                 strbuf_reset(&buf);
1676                 strbuf_addstr(&buf, options.upstream_name);
1677                 strbuf_addstr(&buf, "...");
1678                 strbuf_addstr(&buf, branch_name);
1679                 options.onto_name = keep_base_onto_name = xstrdup(buf.buf);
1680         } else if (!options.onto_name)
1681                 options.onto_name = options.upstream_name;
1682         if (strstr(options.onto_name, "...")) {
1683                 if (repo_get_oid_mb(the_repository, options.onto_name, &branch_base) < 0) {
1684                         if (keep_base)
1685                                 die(_("'%s': need exactly one merge base with branch"),
1686                                     options.upstream_name);
1687                         else
1688                                 die(_("'%s': need exactly one merge base"),
1689                                     options.onto_name);
1690                 }
1691                 options.onto = lookup_commit_or_die(&branch_base,
1692                                                     options.onto_name);
1693         } else {
1694                 options.onto =
1695                         lookup_commit_reference_by_name(options.onto_name);
1696                 if (!options.onto)
1697                         die(_("Does not point to a valid commit '%s'"),
1698                                 options.onto_name);
1699                 fill_branch_base(&options, &branch_base);
1700         }
1701
1702         if (keep_base && options.reapply_cherry_picks)
1703                 options.upstream = options.onto;
1704
1705         if (options.fork_point > 0)
1706                 options.restrict_revision =
1707                         get_fork_point(options.upstream_name, options.orig_head);
1708
1709         if (repo_read_index(the_repository) < 0)
1710                 die(_("could not read index"));
1711
1712         if (options.autostash)
1713                 create_autostash(the_repository,
1714                                  state_dir_path("autostash", &options));
1715
1716
1717         if (require_clean_work_tree(the_repository, "rebase",
1718                                     _("Please commit or stash them."), 1, 1)) {
1719                 ret = -1;
1720                 goto cleanup;
1721         }
1722
1723         /*
1724          * Now we are rebasing commits upstream..orig_head (or with --root,
1725          * everything leading up to orig_head) on top of onto.
1726          */
1727
1728         /*
1729          * Check if we are already based on onto with linear history,
1730          * in which case we could fast-forward without replacing the commits
1731          * with new commits recreated by replaying their changes.
1732          */
1733         if (allow_preemptive_ff &&
1734             can_fast_forward(options.onto, options.upstream, options.restrict_revision,
1735                              options.orig_head, &branch_base)) {
1736                 int flag;
1737
1738                 if (!(options.flags & REBASE_FORCE)) {
1739                         /* Lazily switch to the target branch if needed... */
1740                         if (options.switch_to) {
1741                                 ret = checkout_up_to_date(&options);
1742                                 if (ret)
1743                                         goto cleanup;
1744                         }
1745
1746                         if (!(options.flags & REBASE_NO_QUIET))
1747                                 ; /* be quiet */
1748                         else if (!strcmp(branch_name, "HEAD") &&
1749                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1750                                 puts(_("HEAD is up to date."));
1751                         else
1752                                 printf(_("Current branch %s is up to date.\n"),
1753                                        branch_name);
1754                         ret = finish_rebase(&options);
1755                         goto cleanup;
1756                 } else if (!(options.flags & REBASE_NO_QUIET))
1757                         ; /* be quiet */
1758                 else if (!strcmp(branch_name, "HEAD") &&
1759                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1760                         puts(_("HEAD is up to date, rebase forced."));
1761                 else
1762                         printf(_("Current branch %s is up to date, rebase "
1763                                  "forced.\n"), branch_name);
1764         }
1765
1766         /* If a hook exists, give it a chance to interrupt*/
1767         if (!ok_to_skip_pre_rebase &&
1768             run_hooks_l("pre-rebase", options.upstream_arg,
1769                         argc ? argv[0] : NULL, NULL))
1770                 die(_("The pre-rebase hook refused to rebase."));
1771
1772         if (options.flags & REBASE_DIFFSTAT) {
1773                 struct diff_options opts;
1774
1775                 if (options.flags & REBASE_VERBOSE) {
1776                         if (is_null_oid(&branch_base))
1777                                 printf(_("Changes to %s:\n"),
1778                                        oid_to_hex(&options.onto->object.oid));
1779                         else
1780                                 printf(_("Changes from %s to %s:\n"),
1781                                        oid_to_hex(&branch_base),
1782                                        oid_to_hex(&options.onto->object.oid));
1783                 }
1784
1785                 /* We want color (if set), but no pager */
1786                 repo_diff_setup(the_repository, &opts);
1787                 init_diffstat_widths(&opts);
1788                 opts.output_format |=
1789                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1790                 opts.detect_rename = DIFF_DETECT_RENAME;
1791                 diff_setup_done(&opts);
1792                 diff_tree_oid(is_null_oid(&branch_base) ?
1793                               the_hash_algo->empty_tree : &branch_base,
1794                               &options.onto->object.oid, "", &opts);
1795                 diffcore_std(&opts);
1796                 diff_flush(&opts);
1797         }
1798
1799         if (is_merge(&options))
1800                 goto run_rebase;
1801
1802         /* Detach HEAD and reset the tree */
1803         if (options.flags & REBASE_NO_QUIET)
1804                 printf(_("First, rewinding head to replay your work on top of "
1805                          "it...\n"));
1806
1807         strbuf_addf(&msg, "%s (start): checkout %s",
1808                     options.reflog_action, options.onto_name);
1809         ropts.oid = &options.onto->object.oid;
1810         ropts.orig_head = &options.orig_head->object.oid,
1811         ropts.flags = RESET_HEAD_DETACH | RESET_ORIG_HEAD |
1812                         RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
1813         ropts.head_msg = msg.buf;
1814         ropts.default_reflog_action = options.reflog_action;
1815         if (reset_head(the_repository, &ropts))
1816                 die(_("Could not detach HEAD"));
1817         strbuf_release(&msg);
1818
1819         /*
1820          * If the onto is a proper descendant of the tip of the branch, then
1821          * we just fast-forwarded.
1822          */
1823         if (oideq(&branch_base, &options.orig_head->object.oid)) {
1824                 printf(_("Fast-forwarded %s to %s.\n"),
1825                         branch_name, options.onto_name);
1826                 move_to_original_branch(&options);
1827                 ret = finish_rebase(&options);
1828                 goto cleanup;
1829         }
1830
1831         strbuf_addf(&revisions, "%s..%s",
1832                     options.root ? oid_to_hex(&options.onto->object.oid) :
1833                     (options.restrict_revision ?
1834                      oid_to_hex(&options.restrict_revision->object.oid) :
1835                      oid_to_hex(&options.upstream->object.oid)),
1836                     oid_to_hex(&options.orig_head->object.oid));
1837
1838         options.revisions = revisions.buf;
1839
1840 run_rebase:
1841         ret = run_specific_rebase(&options);
1842
1843 cleanup:
1844         strbuf_release(&buf);
1845         strbuf_release(&revisions);
1846         free(options.reflog_action);
1847         free(options.head_name);
1848         strvec_clear(&options.git_am_opts);
1849         free(options.gpg_sign_opt);
1850         string_list_clear(&options.exec, 0);
1851         free(options.strategy);
1852         string_list_clear(&options.strategy_opts, 0);
1853         strbuf_release(&options.git_format_patch_opt);
1854         free(squash_onto_name);
1855         free(keep_base_onto_name);
1856         return !!ret;
1857 }