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 "strvec.h"
  15 #include "dir.h"
  16 #include "refs.h"
  17 #include "config.h"
  18 #include "unpack-trees.h"
  19 #include "lockfile.h"
  20 #include "object-file.h"
  21 #include "object-name.h"
  22 #include "parse-options.h"
  23 #include "path.h"
  24 #include "commit.h"
  25 #include "diff.h"
  26 #include "wt-status.h"
  27 #include "revision.h"
  28 #include "commit-reach.h"
  29 #include "rerere.h"
  30 #include "branch.h"
  31 #include "sequencer.h"
  32 #include "rebase-interactive.h"
  33 #include "reset.h"
  34 #include "trace2.h"
  35 #include "hook.h"
  36
  37 static char const * const builtin_rebase_usage[] = {
  38         N_("git rebase [-i] [options] [--exec <cmd>] "
  39                 "[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
  40         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  41                 "--root [<branch>]"),
  42         "git rebase --continue | --abort | --skip | --edit-todo",
  43         NULL
  44 };
  45
  46 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
  47 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
  48 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  49 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  50
  51 enum rebase_type {
  52         REBASE_UNSPECIFIED = -1,
  53         REBASE_APPLY,
  54         REBASE_MERGE
  55 };
  56
  57 enum empty_type {
  58         EMPTY_UNSPECIFIED = -1,
  59         EMPTY_DROP,
  60         EMPTY_KEEP,
  61         EMPTY_ASK
  62 };
  63
  64 enum action {
  65         ACTION_NONE = 0,
  66         ACTION_CONTINUE,
  67         ACTION_SKIP,
  68         ACTION_ABORT,
  69         ACTION_QUIT,
  70         ACTION_EDIT_TODO,
  71         ACTION_SHOW_CURRENT_PATCH
  72 };
  73
  74 static const char *action_names[] = {
  75         "undefined",
  76         "continue",
  77         "skip",
  78         "abort",
  79         "quit",
  80         "edit_todo",
  81         "show_current_patch"
  82 };
  83
  84 struct rebase_options {
  85         enum rebase_type type;
  86         enum empty_type empty;
  87         const char *default_backend;
  88         const char *state_dir;
  89         struct commit *upstream;
  90         const char *upstream_name;
  91         const char *upstream_arg;
  92         char *head_name;
  93         struct commit *orig_head;
  94         struct commit *onto;
  95         const char *onto_name;
  96         const char *revisions;
  97         const char *switch_to;
  98         int root, root_with_onto;
  99         struct object_id *squash_onto;
 100         struct commit *restrict_revision;
 101         int dont_finish_rebase;
 102         enum {
 103                 REBASE_NO_QUIET = 1<<0,
 104                 REBASE_VERBOSE = 1<<1,
 105                 REBASE_DIFFSTAT = 1<<2,
 106                 REBASE_FORCE = 1<<3,
 107                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
 108         } flags;
 109         struct strvec git_am_opts;
 110         enum action action;
 111         char *reflog_action;
 112         int signoff;
 113         int allow_rerere_autoupdate;
 114         int keep_empty;
 115         int autosquash;
 116         char *gpg_sign_opt;
 117         int autostash;
 118         int committer_date_is_author_date;
 119         int ignore_date;
 120         struct string_list exec;
 121         int allow_empty_message;
 122         int rebase_merges, rebase_cousins;
 123         char *strategy;
 124         struct string_list strategy_opts;
 125         struct strbuf git_format_patch_opt;
 126         int reschedule_failed_exec;
 127         int reapply_cherry_picks;
 128         int fork_point;
 129         int update_refs;
 130         int config_autosquash;
 131         int config_rebase_merges;
 132         int config_update_refs;
 133 };
 134
 135 #define REBASE_OPTIONS_INIT {                           \
 136                 .type = REBASE_UNSPECIFIED,             \
 137                 .empty = EMPTY_UNSPECIFIED,             \
 138                 .keep_empty = 1,                        \
 139                 .default_backend = "merge",             \
 140                 .flags = REBASE_NO_QUIET,               \
 141                 .git_am_opts = STRVEC_INIT,             \
 142                 .exec = STRING_LIST_INIT_NODUP,         \
 143                 .git_format_patch_opt = STRBUF_INIT,    \
 144                 .fork_point = -1,                       \
 145                 .reapply_cherry_picks = -1,             \
 146                 .allow_empty_message = 1,               \
 147                 .autosquash = -1,                       \
 148                 .rebase_merges = -1,                    \
 149                 .config_rebase_merges = -1,             \
 150                 .update_refs = -1,                      \
 151                 .config_update_refs = -1,               \
 152                 .strategy_opts = STRING_LIST_INIT_NODUP,\
 153         }
 154
 155 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 156 {
 157         struct replay_opts replay = REPLAY_OPTS_INIT;
 158
 159         replay.action = REPLAY_INTERACTIVE_REBASE;
 160         replay.strategy = NULL;
 161         sequencer_init_config(&replay);
 162
 163         replay.signoff = opts->signoff;
 164         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 165         if (opts->allow_rerere_autoupdate)
 166                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 167         replay.allow_empty = 1;
 168         replay.allow_empty_message = opts->allow_empty_message;
 169         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
 170         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
 171         replay.quiet = !(opts->flags & REBASE_NO_QUIET);
 172         replay.verbose = opts->flags & REBASE_VERBOSE;
 173         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 174         replay.committer_date_is_author_date =
 175                                         opts->committer_date_is_author_date;
 176         replay.ignore_date = opts->ignore_date;
 177         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 178         replay.reflog_action = xstrdup(opts->reflog_action);
 179         if (opts->strategy)
 180                 replay.strategy = xstrdup_or_null(opts->strategy);
 181         else if (!replay.strategy && replay.default_strategy) {
 182                 replay.strategy = replay.default_strategy;
 183                 replay.default_strategy = NULL;
 184         }
 185
 186         for (size_t i = 0; i < opts->strategy_opts.nr; i++)
 187                 strvec_push(&replay.xopts, opts->strategy_opts.items[i].string);
 188
 189         if (opts->squash_onto) {
 190                 oidcpy(&replay.squash_onto, opts->squash_onto);
 191                 replay.have_squash_onto = 1;
 192         }
 193
 194         return replay;
 195 }
 196
 197 static int edit_todo_file(unsigned flags)
 198 {
 199         const char *todo_file = rebase_path_todo();
 200         struct todo_list todo_list = TODO_LIST_INIT,
 201                 new_todo = TODO_LIST_INIT;
 202         int res = 0;
 203
 204         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 205                 return error_errno(_("could not read '%s'."), todo_file);
 206
 207         strbuf_stripspace(&todo_list.buf, comment_line_char);
 208         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 209         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 210                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 211                 res = error_errno(_("could not write '%s'"), todo_file);
 212
 213         todo_list_release(&todo_list);
 214         todo_list_release(&new_todo);
 215
 216         return res;
 217 }
 218
 219 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 220                                struct object_id *orig_head, char **revisions,
 221                                char **shortrevisions)
 222 {
 223         struct commit *base_rev = upstream ? upstream : onto;
 224         const char *shorthead;
 225
 226         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 227                              oid_to_hex(orig_head));
 228
 229         shorthead = repo_find_unique_abbrev(the_repository, orig_head,
 230                                             DEFAULT_ABBREV);
 231
 232         if (upstream) {
 233                 const char *shortrev;
 234
 235                 shortrev = repo_find_unique_abbrev(the_repository,
 236                                                    &base_rev->object.oid,
 237                                                    DEFAULT_ABBREV);
 238
 239                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 240         } else
 241                 *shortrevisions = xstrdup(shorthead);
 242
 243         return 0;
 244 }
 245
 246 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 247                             struct commit *onto,
 248                             const struct object_id *orig_head)
 249 {
 250         FILE *interactive;
 251
 252         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 253                 return error_errno(_("could not create temporary %s"), merge_dir());
 254
 255         delete_reflog("REBASE_HEAD");
 256
 257         interactive = fopen(path_interactive(), "w");
 258         if (!interactive)
 259                 return error_errno(_("could not mark as interactive"));
 260         fclose(interactive);
 261
 262         return write_basic_state(opts, head_name, onto, orig_head);
 263 }
 264
 265 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 266 {
 267         int ret = -1;
 268         char *revisions = NULL, *shortrevisions = NULL;
 269         struct strvec make_script_args = STRVEC_INIT;
 270         struct todo_list todo_list = TODO_LIST_INIT;
 271         struct replay_opts replay = get_replay_opts(opts);
 272
 273         if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head->object.oid,
 274                                 &revisions, &shortrevisions))
 275                 goto cleanup;
 276
 277         if (init_basic_state(&replay,
 278                              opts->head_name ? opts->head_name : "detached HEAD",
 279                              opts->onto, &opts->orig_head->object.oid))
 280                 goto cleanup;
 281
 282         if (!opts->upstream && opts->squash_onto)
 283                 write_file(path_squash_onto(), "%s\n",
 284                            oid_to_hex(opts->squash_onto));
 285
 286         strvec_pushl(&make_script_args, "", revisions, NULL);
 287         if (opts->restrict_revision)
 288                 strvec_pushf(&make_script_args, "^%s",
 289                              oid_to_hex(&opts->restrict_revision->object.oid));
 290
 291         ret = sequencer_make_script(the_repository, &todo_list.buf,
 292                                     make_script_args.nr, make_script_args.v,
 293                                     flags);
 294
 295         if (ret)
 296                 error(_("could not generate todo list"));
 297         else {
 298                 discard_index(&the_index);
 299                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 300                                                 &todo_list))
 301                         BUG("unusable todo list");
 302
 303                 ret = complete_action(the_repository, &replay, flags,
 304                         shortrevisions, opts->onto_name, opts->onto,
 305                         &opts->orig_head->object.oid, &opts->exec,
 306                         opts->autosquash, opts->update_refs, &todo_list);
 307         }
 308
 309 cleanup:
 310         replay_opts_release(&replay);
 311         free(revisions);
 312         free(shortrevisions);
 313         todo_list_release(&todo_list);
 314         strvec_clear(&make_script_args);
 315
 316         return ret;
 317 }
 318
 319 static int run_sequencer_rebase(struct rebase_options *opts)
 320 {
 321         unsigned flags = 0;
 322         int abbreviate_commands = 0, ret = 0;
 323
 324         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 325
 326         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 327         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 328         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 329         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 330         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 331         flags |= opts->reapply_cherry_picks ? TODO_LIST_REAPPLY_CHERRY_PICKS : 0;
 332         flags |= opts->flags & REBASE_NO_QUIET ? TODO_LIST_WARN_SKIPPED_CHERRY_PICKS : 0;
 333
 334         switch (opts->action) {
 335         case ACTION_NONE: {
 336                 if (!opts->onto && !opts->upstream)
 337                         die(_("a base commit must be provided with --upstream or --onto"));
 338
 339                 ret = do_interactive_rebase(opts, flags);
 340                 break;
 341         }
 342         case ACTION_SKIP: {
 343                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 344
 345                 rerere_clear(the_repository, &merge_rr);
 346         }
 347                 /* fallthrough */
 348         case ACTION_CONTINUE: {
 349                 struct replay_opts replay_opts = get_replay_opts(opts);
 350
 351                 ret = sequencer_continue(the_repository, &replay_opts);
 352                 replay_opts_release(&replay_opts);
 353                 break;
 354         }
 355         case ACTION_EDIT_TODO:
 356                 ret = edit_todo_file(flags);
 357                 break;
 358         case ACTION_SHOW_CURRENT_PATCH: {
 359                 struct child_process cmd = CHILD_PROCESS_INIT;
 360
 361                 cmd.git_cmd = 1;
 362                 strvec_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 363                 ret = run_command(&cmd);
 364
 365                 break;
 366         }
 367         default:
 368                 BUG("invalid command '%d'", opts->action);
 369         }
 370
 371         return ret;
 372 }
 373
 374 static int is_merge(struct rebase_options *opts)
 375 {
 376         return opts->type == REBASE_MERGE;
 377 }
 378
 379 static void imply_merge(struct rebase_options *opts, const char *option)
 380 {
 381         switch (opts->type) {
 382         case REBASE_APPLY:
 383                 die(_("%s requires the merge backend"), option);
 384                 break;
 385         case REBASE_MERGE:
 386                 break;
 387         default:
 388                 opts->type = REBASE_MERGE; /* implied */
 389                 break;
 390         }
 391 }
 392
 393 /* Returns the filename prefixed by the state_dir */
 394 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 395 {
 396         static struct strbuf path = STRBUF_INIT;
 397         static size_t prefix_len;
 398
 399         if (!prefix_len) {
 400                 strbuf_addf(&path, "%s/", opts->state_dir);
 401                 prefix_len = path.len;
 402         }
 403
 404         strbuf_setlen(&path, prefix_len);
 405         strbuf_addstr(&path, filename);
 406         return path.buf;
 407 }
 408
 409 /* Initialize the rebase options from the state directory. */
 410 static int read_basic_state(struct rebase_options *opts)
 411 {
 412         struct strbuf head_name = STRBUF_INIT;
 413         struct strbuf buf = STRBUF_INIT;
 414         struct object_id oid;
 415
 416         if (!read_oneliner(&head_name, state_dir_path("head-name", opts),
 417                            READ_ONELINER_WARN_MISSING) ||
 418             !read_oneliner(&buf, state_dir_path("onto", opts),
 419                            READ_ONELINER_WARN_MISSING))
 420                 return -1;
 421         opts->head_name = starts_with(head_name.buf, "refs/") ?
 422                 xstrdup(head_name.buf) : NULL;
 423         strbuf_release(&head_name);
 424         if (get_oid_hex(buf.buf, &oid) ||
 425             !(opts->onto = lookup_commit_object(the_repository, &oid)))
 426                 return error(_("invalid onto: '%s'"), buf.buf);
 427
 428         /*
 429          * We always write to orig-head, but interactive rebase used to write to
 430          * head. Fall back to reading from head to cover for the case that the
 431          * user upgraded git with an ongoing interactive rebase.
 432          */
 433         strbuf_reset(&buf);
 434         if (file_exists(state_dir_path("orig-head", opts))) {
 435                 if (!read_oneliner(&buf, state_dir_path("orig-head", opts),
 436                                    READ_ONELINER_WARN_MISSING))
 437                         return -1;
 438         } else if (!read_oneliner(&buf, state_dir_path("head", opts),
 439                                   READ_ONELINER_WARN_MISSING))
 440                 return -1;
 441         if (get_oid_hex(buf.buf, &oid) ||
 442             !(opts->orig_head = lookup_commit_object(the_repository, &oid)))
 443                 return error(_("invalid orig-head: '%s'"), buf.buf);
 444
 445         if (file_exists(state_dir_path("quiet", opts)))
 446                 opts->flags &= ~REBASE_NO_QUIET;
 447         else
 448                 opts->flags |= REBASE_NO_QUIET;
 449
 450         if (file_exists(state_dir_path("verbose", opts)))
 451                 opts->flags |= REBASE_VERBOSE;
 452
 453         if (file_exists(state_dir_path("signoff", opts))) {
 454                 opts->signoff = 1;
 455                 opts->flags |= REBASE_FORCE;
 456         }
 457
 458         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 459                 strbuf_reset(&buf);
 460                 if (!read_oneliner(&buf, state_dir_path("allow_rerere_autoupdate", opts),
 461                                    READ_ONELINER_WARN_MISSING))
 462                         return -1;
 463                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 464                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 465                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 466                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 467                 else
 468                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 469                                   "'%s'"), buf.buf);
 470         }
 471
 472         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 473                 strbuf_reset(&buf);
 474                 if (!read_oneliner(&buf, state_dir_path("gpg_sign_opt", opts),
 475                                    READ_ONELINER_WARN_MISSING))
 476                         return -1;
 477                 free(opts->gpg_sign_opt);
 478                 opts->gpg_sign_opt = xstrdup(buf.buf);
 479         }
 480
 481         strbuf_release(&buf);
 482
 483         return 0;
 484 }
 485
 486 static int rebase_write_basic_state(struct rebase_options *opts)
 487 {
 488         write_file(state_dir_path("head-name", opts), "%s",
 489                    opts->head_name ? opts->head_name : "detached HEAD");
 490         write_file(state_dir_path("onto", opts), "%s",
 491                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 492         write_file(state_dir_path("orig-head", opts), "%s",
 493                    oid_to_hex(&opts->orig_head->object.oid));
 494         if (!(opts->flags & REBASE_NO_QUIET))
 495                 write_file(state_dir_path("quiet", opts), "%s", "");
 496         if (opts->flags & REBASE_VERBOSE)
 497                 write_file(state_dir_path("verbose", opts), "%s", "");
 498         if (opts->allow_rerere_autoupdate > 0)
 499                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 500                            "-%s-rerere-autoupdate",
 501                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 502                                 "" : "-no");
 503         if (opts->gpg_sign_opt)
 504                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 505                            opts->gpg_sign_opt);
 506         if (opts->signoff)
 507                 write_file(state_dir_path("signoff", opts), "--signoff");
 508
 509         return 0;
 510 }
 511
 512 static int finish_rebase(struct rebase_options *opts)
 513 {
 514         struct strbuf dir = STRBUF_INIT;
 515         int ret = 0;
 516
 517         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 518         delete_ref(NULL, "AUTO_MERGE", NULL, REF_NO_DEREF);
 519         apply_autostash(state_dir_path("autostash", opts));
 520         /*
 521          * We ignore errors in 'git maintenance run --auto', since the
 522          * user should see them.
 523          */
 524         run_auto_maintenance(!(opts->flags & (REBASE_NO_QUIET|REBASE_VERBOSE)));
 525         if (opts->type == REBASE_MERGE) {
 526                 struct replay_opts replay = REPLAY_OPTS_INIT;
 527
 528                 replay.action = REPLAY_INTERACTIVE_REBASE;
 529                 ret = sequencer_remove_state(&replay);
 530                 replay_opts_release(&replay);
 531         } else {
 532                 strbuf_addstr(&dir, opts->state_dir);
 533                 if (remove_dir_recursively(&dir, 0))
 534                         ret = error(_("could not remove '%s'"),
 535                                     opts->state_dir);
 536                 strbuf_release(&dir);
 537         }
 538
 539         return ret;
 540 }
 541
 542 static int move_to_original_branch(struct rebase_options *opts)
 543 {
 544         struct strbuf branch_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 545         struct reset_head_opts ropts = { 0 };
 546         int ret;
 547
 548         if (!opts->head_name)
 549                 return 0; /* nothing to move back to */
 550
 551         if (!opts->onto)
 552                 BUG("move_to_original_branch without onto");
 553
 554         strbuf_addf(&branch_reflog, "%s (finish): %s onto %s",
 555                     opts->reflog_action,
 556                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 557         strbuf_addf(&head_reflog, "%s (finish): returning to %s",
 558                     opts->reflog_action, opts->head_name);
 559         ropts.branch = opts->head_name;
 560         ropts.flags = RESET_HEAD_REFS_ONLY;
 561         ropts.branch_msg = branch_reflog.buf;
 562         ropts.head_msg = head_reflog.buf;
 563         ret = reset_head(the_repository, &ropts);
 564
 565         strbuf_release(&branch_reflog);
 566         strbuf_release(&head_reflog);
 567         return ret;
 568 }
 569
 570 static const char *resolvemsg =
 571 N_("Resolve all conflicts manually, mark them as resolved with\n"
 572 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 573 "You can instead skip this commit: run \"git rebase --skip\".\n"
 574 "To abort and get back to the state before \"git rebase\", run "
 575 "\"git rebase --abort\".");
 576
 577 static int run_am(struct rebase_options *opts)
 578 {
 579         struct child_process am = CHILD_PROCESS_INIT;
 580         struct child_process format_patch = CHILD_PROCESS_INIT;
 581         int status;
 582         char *rebased_patches;
 583
 584         am.git_cmd = 1;
 585         strvec_push(&am.args, "am");
 586         strvec_pushf(&am.env, GIT_REFLOG_ACTION_ENVIRONMENT "=%s (pick)",
 587                      opts->reflog_action);
 588         if (opts->action == ACTION_CONTINUE) {
 589                 strvec_push(&am.args, "--resolved");
 590                 strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 591                 if (opts->gpg_sign_opt)
 592                         strvec_push(&am.args, opts->gpg_sign_opt);
 593                 status = run_command(&am);
 594                 if (status)
 595                         return status;
 596
 597                 return move_to_original_branch(opts);
 598         }
 599         if (opts->action == ACTION_SKIP) {
 600                 strvec_push(&am.args, "--skip");
 601                 strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 602                 status = run_command(&am);
 603                 if (status)
 604                         return status;
 605
 606                 return move_to_original_branch(opts);
 607         }
 608         if (opts->action == ACTION_SHOW_CURRENT_PATCH) {
 609                 strvec_push(&am.args, "--show-current-patch");
 610                 return run_command(&am);
 611         }
 612
 613         rebased_patches = xstrdup(git_path("rebased-patches"));
 614         format_patch.out = open(rebased_patches,
 615                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
 616         if (format_patch.out < 0) {
 617                 status = error_errno(_("could not open '%s' for writing"),
 618                                      rebased_patches);
 619                 free(rebased_patches);
 620                 strvec_clear(&am.args);
 621                 return status;
 622         }
 623
 624         format_patch.git_cmd = 1;
 625         strvec_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
 626                      "--full-index", "--cherry-pick", "--right-only",
 627                      "--default-prefix", "--no-renames",
 628                      "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
 629                      "--no-base", NULL);
 630         if (opts->git_format_patch_opt.len)
 631                 strvec_split(&format_patch.args,
 632                              opts->git_format_patch_opt.buf);
 633         strvec_pushf(&format_patch.args, "%s...%s",
 634                      oid_to_hex(opts->root ?
 635                                 /* this is now equivalent to !opts->upstream */
 636                                 &opts->onto->object.oid :
 637                                 &opts->upstream->object.oid),
 638                      oid_to_hex(&opts->orig_head->object.oid));
 639         if (opts->restrict_revision)
 640                 strvec_pushf(&format_patch.args, "^%s",
 641                              oid_to_hex(&opts->restrict_revision->object.oid));
 642
 643         status = run_command(&format_patch);
 644         if (status) {
 645                 struct reset_head_opts ropts = { 0 };
 646                 unlink(rebased_patches);
 647                 free(rebased_patches);
 648                 strvec_clear(&am.args);
 649
 650                 ropts.oid = &opts->orig_head->object.oid;
 651                 ropts.branch = opts->head_name;
 652                 ropts.default_reflog_action = opts->reflog_action;
 653                 reset_head(the_repository, &ropts);
 654                 error(_("\ngit encountered an error while preparing the "
 655                         "patches to replay\n"
 656                         "these revisions:\n"
 657                         "\n    %s\n\n"
 658                         "As a result, git cannot rebase them."),
 659                       opts->revisions);
 660
 661                 return status;
 662         }
 663
 664         am.in = open(rebased_patches, O_RDONLY);
 665         if (am.in < 0) {
 666                 status = error_errno(_("could not open '%s' for reading"),
 667                                      rebased_patches);
 668                 free(rebased_patches);
 669                 strvec_clear(&am.args);
 670                 return status;
 671         }
 672
 673         strvec_pushv(&am.args, opts->git_am_opts.v);
 674         strvec_push(&am.args, "--rebasing");
 675         strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 676         strvec_push(&am.args, "--patch-format=mboxrd");
 677         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
 678                 strvec_push(&am.args, "--rerere-autoupdate");
 679         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
 680                 strvec_push(&am.args, "--no-rerere-autoupdate");
 681         if (opts->gpg_sign_opt)
 682                 strvec_push(&am.args, opts->gpg_sign_opt);
 683         status = run_command(&am);
 684         unlink(rebased_patches);
 685         free(rebased_patches);
 686
 687         if (!status) {
 688                 return move_to_original_branch(opts);
 689         }
 690
 691         if (is_directory(opts->state_dir))
 692                 rebase_write_basic_state(opts);
 693
 694         return status;
 695 }
 696
 697 static int run_specific_rebase(struct rebase_options *opts)
 698 {
 699         int status;
 700
 701         if (opts->type == REBASE_MERGE) {
 702                 /* Run sequencer-based rebase */
 703                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
 704                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT))
 705                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
 706                 if (opts->gpg_sign_opt) {
 707                         /* remove the leading "-S" */
 708                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
 709                         free(opts->gpg_sign_opt);
 710                         opts->gpg_sign_opt = tmp;
 711                 }
 712
 713                 status = run_sequencer_rebase(opts);
 714         } else if (opts->type == REBASE_APPLY)
 715                 status = run_am(opts);
 716         else
 717                 BUG("Unhandled rebase type %d", opts->type);
 718
 719         if (opts->dont_finish_rebase)
 720                 ; /* do nothing */
 721         else if (opts->type == REBASE_MERGE)
 722                 ; /* merge backend cleans up after itself */
 723         else if (status == 0) {
 724                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 725                         finish_rebase(opts);
 726         } else if (status == 2) {
 727                 struct strbuf dir = STRBUF_INIT;
 728
 729                 apply_autostash(state_dir_path("autostash", opts));
 730                 strbuf_addstr(&dir, opts->state_dir);
 731                 remove_dir_recursively(&dir, 0);
 732                 strbuf_release(&dir);
 733                 die("Nothing to do");
 734         }
 735
 736         return status ? -1 : 0;
 737 }
 738
 739 static void parse_rebase_merges_value(struct rebase_options *options, const char *value)
 740 {
 741         if (!strcmp("no-rebase-cousins", value))
 742                 options->rebase_cousins = 0;
 743         else if (!strcmp("rebase-cousins", value))
 744                 options->rebase_cousins = 1;
 745         else
 746                 die(_("Unknown rebase-merges mode: %s"), value);
 747 }
 748
 749 static int rebase_config(const char *var, const char *value,
 750                          const struct config_context *ctx, void *data)
 751 {
 752         struct rebase_options *opts = data;
 753
 754         if (!strcmp(var, "rebase.stat")) {
 755                 if (git_config_bool(var, value))
 756                         opts->flags |= REBASE_DIFFSTAT;
 757                 else
 758                         opts->flags &= ~REBASE_DIFFSTAT;
 759                 return 0;
 760         }
 761
 762         if (!strcmp(var, "rebase.autosquash")) {
 763                 opts->config_autosquash = git_config_bool(var, value);
 764                 return 0;
 765         }
 766
 767         if (!strcmp(var, "commit.gpgsign")) {
 768                 free(opts->gpg_sign_opt);
 769                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 770                         xstrdup("-S") : NULL;
 771                 return 0;
 772         }
 773
 774         if (!strcmp(var, "rebase.autostash")) {
 775                 opts->autostash = git_config_bool(var, value);
 776                 return 0;
 777         }
 778
 779         if (!strcmp(var, "rebase.rebasemerges")) {
 780                 opts->config_rebase_merges = git_parse_maybe_bool(value);
 781                 if (opts->config_rebase_merges < 0) {
 782                         opts->config_rebase_merges = 1;
 783                         parse_rebase_merges_value(opts, value);
 784                 } else {
 785                         opts->rebase_cousins = 0;
 786                 }
 787                 return 0;
 788         }
 789
 790         if (!strcmp(var, "rebase.updaterefs")) {
 791                 opts->config_update_refs = git_config_bool(var, value);
 792                 return 0;
 793         }
 794
 795         if (!strcmp(var, "rebase.reschedulefailedexec")) {
 796                 opts->reschedule_failed_exec = git_config_bool(var, value);
 797                 return 0;
 798         }
 799
 800         if (!strcmp(var, "rebase.forkpoint")) {
 801                 opts->fork_point = git_config_bool(var, value) ? -1 : 0;
 802                 return 0;
 803         }
 804
 805         if (!strcmp(var, "rebase.backend")) {
 806                 return git_config_string(&opts->default_backend, var, value);
 807         }
 808
 809         return git_default_config(var, value, ctx, data);
 810 }
 811
 812 static int checkout_up_to_date(struct rebase_options *options)
 813 {
 814         struct strbuf buf = STRBUF_INIT;
 815         struct reset_head_opts ropts = { 0 };
 816         int ret = 0;
 817
 818         strbuf_addf(&buf, "%s: checkout %s",
 819                     options->reflog_action, options->switch_to);
 820         ropts.oid = &options->orig_head->object.oid;
 821         ropts.branch = options->head_name;
 822         ropts.flags = RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 823         if (!ropts.branch)
 824                 ropts.flags |=  RESET_HEAD_DETACH;
 825         ropts.head_msg = buf.buf;
 826         if (reset_head(the_repository, &ropts) < 0)
 827                 ret = error(_("could not switch to %s"), options->switch_to);
 828         strbuf_release(&buf);
 829
 830         return ret;
 831 }
 832
 833 /*
 834  * Determines whether the commits in from..to are linear, i.e. contain
 835  * no merge commits. This function *expects* `from` to be an ancestor of
 836  * `to`.
 837  */
 838 static int is_linear_history(struct commit *from, struct commit *to)
 839 {
 840         while (to && to != from) {
 841                 repo_parse_commit(the_repository, to);
 842                 if (!to->parents)
 843                         return 1;
 844                 if (to->parents->next)
 845                         return 0;
 846                 to = to->parents->item;
 847         }
 848         return 1;
 849 }
 850
 851 static int can_fast_forward(struct commit *onto, struct commit *upstream,
 852                             struct commit *restrict_revision,
 853                             struct commit *head, struct object_id *branch_base)
 854 {
 855         struct commit_list *merge_bases = NULL;
 856         int res = 0;
 857
 858         if (is_null_oid(branch_base))
 859                 goto done; /* fill_branch_base() found multiple merge bases */
 860
 861         if (!oideq(branch_base, &onto->object.oid))
 862                 goto done;
 863
 864         if (restrict_revision && !oideq(&restrict_revision->object.oid, branch_base))
 865                 goto done;
 866
 867         if (!upstream)
 868                 goto done;
 869
 870         merge_bases = repo_get_merge_bases(the_repository, upstream, head);
 871         if (!merge_bases || merge_bases->next)
 872                 goto done;
 873
 874         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
 875                 goto done;
 876
 877         res = 1;
 878
 879 done:
 880         free_commit_list(merge_bases);
 881         return res && is_linear_history(onto, head);
 882 }
 883
 884 static void fill_branch_base(struct rebase_options *options,
 885                             struct object_id *branch_base)
 886 {
 887         struct commit_list *merge_bases = NULL;
 888
 889         merge_bases = repo_get_merge_bases(the_repository, options->onto,
 890                                            options->orig_head);
 891         if (!merge_bases || merge_bases->next)
 892                 oidcpy(branch_base, null_oid());
 893         else
 894                 oidcpy(branch_base, &merge_bases->item->object.oid);
 895
 896         free_commit_list(merge_bases);
 897 }
 898
 899 static int parse_opt_am(const struct option *opt, const char *arg, int unset)
 900 {
 901         struct rebase_options *opts = opt->value;
 902
 903         BUG_ON_OPT_NEG(unset);
 904         BUG_ON_OPT_ARG(arg);
 905
 906         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_APPLY)
 907             die(_("apply options and merge options cannot be used together"));
 908
 909         opts->type = REBASE_APPLY;
 910
 911         return 0;
 912 }
 913
 914 /* -i followed by -m is still -i */
 915 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 916 {
 917         struct rebase_options *opts = opt->value;
 918
 919         BUG_ON_OPT_NEG(unset);
 920         BUG_ON_OPT_ARG(arg);
 921
 922         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_MERGE)
 923             die(_("apply options and merge options cannot be used together"));
 924
 925         opts->type = REBASE_MERGE;
 926
 927         return 0;
 928 }
 929
 930 /* -i followed by -r is still explicitly interactive, but -r alone is not */
 931 static int parse_opt_interactive(const struct option *opt, const char *arg,
 932                                  int unset)
 933 {
 934         struct rebase_options *opts = opt->value;
 935
 936         BUG_ON_OPT_NEG(unset);
 937         BUG_ON_OPT_ARG(arg);
 938
 939         if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_MERGE)
 940             die(_("apply options and merge options cannot be used together"));
 941
 942         opts->type = REBASE_MERGE;
 943         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 944
 945         return 0;
 946 }
 947
 948 static enum empty_type parse_empty_value(const char *value)
 949 {
 950         if (!strcasecmp(value, "drop"))
 951                 return EMPTY_DROP;
 952         else if (!strcasecmp(value, "keep"))
 953                 return EMPTY_KEEP;
 954         else if (!strcasecmp(value, "ask"))
 955                 return EMPTY_ASK;
 956
 957         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
 958 }
 959
 960 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 961                                 int unset)
 962 {
 963         struct rebase_options *opts = opt->value;
 964
 965         BUG_ON_OPT_ARG(arg);
 966
 967         imply_merge(opts, unset ? "--no-keep-empty" : "--keep-empty");
 968         opts->keep_empty = !unset;
 969         return 0;
 970 }
 971
 972 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
 973 {
 974         struct rebase_options *options = opt->value;
 975         enum empty_type value = parse_empty_value(arg);
 976
 977         BUG_ON_OPT_NEG(unset);
 978
 979         options->empty = value;
 980         return 0;
 981 }
 982
 983 static int parse_opt_rebase_merges(const struct option *opt, const char *arg, int unset)
 984 {
 985         struct rebase_options *options = opt->value;
 986
 987         options->rebase_merges = !unset;
 988         options->rebase_cousins = 0;
 989
 990         if (arg) {
 991                 if (!*arg) {
 992                         warning(_("--rebase-merges with an empty string "
 993                                   "argument is deprecated and will stop "
 994                                   "working in a future version of Git. Use "
 995                                   "--rebase-merges without an argument "
 996                                   "instead, which does the same thing."));
 997                         return 0;
 998                 }
 999                 parse_rebase_merges_value(options, arg);
1000         }
1001
1002         return 0;
1003 }
1004
1005 static void NORETURN error_on_missing_default_upstream(void)
1006 {
1007         struct branch *current_branch = branch_get(NULL);
1008
1009         printf(_("%s\n"
1010                  "Please specify which branch you want to rebase against.\n"
1011                  "See git-rebase(1) for details.\n"
1012                  "\n"
1013                  "    git rebase '<branch>'\n"
1014                  "\n"),
1015                 current_branch ? _("There is no tracking information for "
1016                         "the current branch.") :
1017                         _("You are not currently on a branch."));
1018
1019         if (current_branch) {
1020                 const char *remote = current_branch->remote_name;
1021
1022                 if (!remote)
1023                         remote = _("<remote>");
1024
1025                 printf(_("If you wish to set tracking information for this "
1026                          "branch you can do so with:\n"
1027                          "\n"
1028                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1029                          "\n"),
1030                        remote, current_branch->name);
1031         }
1032         exit(1);
1033 }
1034
1035 static int check_exec_cmd(const char *cmd)
1036 {
1037         if (strchr(cmd, '\n'))
1038                 return error(_("exec commands cannot contain newlines"));
1039
1040         /* Does the command consist purely of whitespace? */
1041         if (!cmd[strspn(cmd, " \t\r\f\v")])
1042                 return error(_("empty exec command"));
1043
1044         return 0;
1045 }
1046
1047 int cmd_rebase(int argc, const char **argv, const char *prefix)
1048 {
1049         struct rebase_options options = REBASE_OPTIONS_INIT;
1050         const char *branch_name;
1051         int ret, flags, total_argc, in_progress = 0;
1052         int keep_base = 0;
1053         int ok_to_skip_pre_rebase = 0;
1054         struct strbuf msg = STRBUF_INIT;
1055         struct strbuf revisions = STRBUF_INIT;
1056         struct strbuf buf = STRBUF_INIT;
1057         struct object_id branch_base;
1058         int ignore_whitespace = 0;
1059         const char *gpg_sign = NULL;
1060         struct object_id squash_onto;
1061         char *squash_onto_name = NULL;
1062         char *keep_base_onto_name = NULL;
1063         int reschedule_failed_exec = -1;
1064         int allow_preemptive_ff = 1;
1065         int preserve_merges_selected = 0;
1066         struct reset_head_opts ropts = { 0 };
1067         struct option builtin_rebase_options[] = {
1068                 OPT_STRING(0, "onto", &options.onto_name,
1069                            N_("revision"),
1070                            N_("rebase onto given branch instead of upstream")),
1071                 OPT_BOOL(0, "keep-base", &keep_base,
1072                          N_("use the merge-base of upstream and branch as the current base")),
1073                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1074                          N_("allow pre-rebase hook to run")),
1075                 OPT_NEGBIT('q', "quiet", &options.flags,
1076                            N_("be quiet. implies --no-stat"),
1077                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1078                 OPT_BIT('v', "verbose", &options.flags,
1079                         N_("display a diffstat of what changed upstream"),
1080                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1081                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1082                         N_("do not show diffstat of what changed upstream"),
1083                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1084                 OPT_BOOL(0, "signoff", &options.signoff,
1085                          N_("add a Signed-off-by trailer to each commit")),
1086                 OPT_BOOL(0, "committer-date-is-author-date",
1087                          &options.committer_date_is_author_date,
1088                          N_("make committer date match author date")),
1089                 OPT_BOOL(0, "reset-author-date", &options.ignore_date,
1090                          N_("ignore author date and use current date")),
1091                 OPT_HIDDEN_BOOL(0, "ignore-date", &options.ignore_date,
1092                                 N_("synonym of --reset-author-date")),
1093                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1094                                   N_("passed to 'git apply'"), 0),
1095                 OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
1096                          N_("ignore changes in whitespace")),
1097                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1098                                   N_("action"), N_("passed to 'git apply'"), 0),
1099                 OPT_BIT('f', "force-rebase", &options.flags,
1100                         N_("cherry-pick all commits, even if unchanged"),
1101                         REBASE_FORCE),
1102                 OPT_BIT(0, "no-ff", &options.flags,
1103                         N_("cherry-pick all commits, even if unchanged"),
1104                         REBASE_FORCE),
1105                 OPT_CMDMODE(0, "continue", &options.action, N_("continue"),
1106                             ACTION_CONTINUE),
1107                 OPT_CMDMODE(0, "skip", &options.action,
1108                             N_("skip current patch and continue"), ACTION_SKIP),
1109                 OPT_CMDMODE(0, "abort", &options.action,
1110                             N_("abort and check out the original branch"),
1111                             ACTION_ABORT),
1112                 OPT_CMDMODE(0, "quit", &options.action,
1113                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1114                 OPT_CMDMODE(0, "edit-todo", &options.action, N_("edit the todo list "
1115                             "during an interactive rebase"), ACTION_EDIT_TODO),
1116                 OPT_CMDMODE(0, "show-current-patch", &options.action,
1117                             N_("show the patch file being applied or merged"),
1118                             ACTION_SHOW_CURRENT_PATCH),
1119                 OPT_CALLBACK_F(0, "apply", &options, NULL,
1120                         N_("use apply strategies to rebase"),
1121                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1122                         parse_opt_am),
1123                 OPT_CALLBACK_F('m', "merge", &options, NULL,
1124                         N_("use merging strategies to rebase"),
1125                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1126                         parse_opt_merge),
1127                 OPT_CALLBACK_F('i', "interactive", &options, NULL,
1128                         N_("let the user edit the list of commits to rebase"),
1129                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1130                         parse_opt_interactive),
1131                 OPT_SET_INT_F('p', "preserve-merges", &preserve_merges_selected,
1132                               N_("(REMOVED) was: try to recreate merges "
1133                                  "instead of ignoring them"),
1134                               1, PARSE_OPT_HIDDEN),
1135                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1136                 OPT_CALLBACK_F(0, "empty", &options, "(drop|keep|ask)",
1137                                N_("how to handle commits that become empty"),
1138                                PARSE_OPT_NONEG, parse_opt_empty),
1139                 OPT_CALLBACK_F('k', "keep-empty", &options, NULL,
1140                         N_("keep commits which start empty"),
1141                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1142                         parse_opt_keep_empty),
1143                 OPT_BOOL(0, "autosquash", &options.autosquash,
1144                          N_("move commits that begin with "
1145                             "squash!/fixup! under -i")),
1146                 OPT_BOOL(0, "update-refs", &options.update_refs,
1147                          N_("update branches that point to commits "
1148                             "that are being rebased")),
1149                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1150                         N_("GPG-sign commits"),
1151                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1152                 OPT_AUTOSTASH(&options.autostash),
1153                 OPT_STRING_LIST('x', "exec", &options.exec, N_("exec"),
1154                                 N_("add exec lines after each commit of the "
1155                                    "editable list")),
1156                 OPT_BOOL_F(0, "allow-empty-message",
1157                            &options.allow_empty_message,
1158                            N_("allow rebasing commits with empty messages"),
1159                            PARSE_OPT_HIDDEN),
1160                 OPT_CALLBACK_F('r', "rebase-merges", &options, N_("mode"),
1161                         N_("try to rebase merges instead of skipping them"),
1162                         PARSE_OPT_OPTARG, parse_opt_rebase_merges),
1163                 OPT_BOOL(0, "fork-point", &options.fork_point,
1164                          N_("use 'merge-base --fork-point' to refine upstream")),
1165                 OPT_STRING('s', "strategy", &options.strategy,
1166                            N_("strategy"), N_("use the given merge strategy")),
1167                 OPT_STRING_LIST('X', "strategy-option", &options.strategy_opts,
1168                                 N_("option"),
1169                                 N_("pass the argument through to the merge "
1170                                    "strategy")),
1171                 OPT_BOOL(0, "root", &options.root,
1172                          N_("rebase all reachable commits up to the root(s)")),
1173                 OPT_BOOL(0, "reschedule-failed-exec",
1174                          &reschedule_failed_exec,
1175                          N_("automatically re-schedule any `exec` that fails")),
1176                 OPT_BOOL(0, "reapply-cherry-picks", &options.reapply_cherry_picks,
1177                          N_("apply all changes, even those already present upstream")),
1178                 OPT_END(),
1179         };
1180         int i;
1181
1182         if (argc == 2 && !strcmp(argv[1], "-h"))
1183                 usage_with_options(builtin_rebase_usage,
1184                                    builtin_rebase_options);
1185
1186         prepare_repo_settings(the_repository);
1187         the_repository->settings.command_requires_full_index = 0;
1188
1189         git_config(rebase_config, &options);
1190         /* options.gpg_sign_opt will be either "-S" or NULL */
1191         gpg_sign = options.gpg_sign_opt ? "" : NULL;
1192         FREE_AND_NULL(options.gpg_sign_opt);
1193
1194         strbuf_reset(&buf);
1195         strbuf_addf(&buf, "%s/applying", apply_dir());
1196         if(file_exists(buf.buf))
1197                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1198
1199         if (is_directory(apply_dir())) {
1200                 options.type = REBASE_APPLY;
1201                 options.state_dir = apply_dir();
1202         } else if (is_directory(merge_dir())) {
1203                 strbuf_reset(&buf);
1204                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1205                 if (!(options.action == ACTION_ABORT) && is_directory(buf.buf)) {
1206                         die(_("`rebase --preserve-merges` (-p) is no longer supported.\n"
1207                         "Use `git rebase --abort` to terminate current rebase.\n"
1208                         "Or downgrade to v2.33, or earlier, to complete the rebase."));
1209                 } else {
1210                         strbuf_reset(&buf);
1211                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1212                         options.type = REBASE_MERGE;
1213                         if (file_exists(buf.buf))
1214                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1215                 }
1216                 options.state_dir = merge_dir();
1217         }
1218
1219         if (options.type != REBASE_UNSPECIFIED)
1220                 in_progress = 1;
1221
1222         total_argc = argc;
1223         argc = parse_options(argc, argv, prefix,
1224                              builtin_rebase_options,
1225                              builtin_rebase_usage, 0);
1226
1227         if (preserve_merges_selected)
1228                 die(_("--preserve-merges was replaced by --rebase-merges\n"
1229                         "Note: Your `pull.rebase` configuration may also be set to 'preserve',\n"
1230                         "which is no longer supported; use 'merges' instead"));
1231
1232         if (options.action != ACTION_NONE && total_argc != 2) {
1233                 usage_with_options(builtin_rebase_usage,
1234                                    builtin_rebase_options);
1235         }
1236
1237         if (argc > 2)
1238                 usage_with_options(builtin_rebase_usage,
1239                                    builtin_rebase_options);
1240
1241         if (keep_base) {
1242                 if (options.onto_name)
1243                         die(_("options '%s' and '%s' cannot be used together"), "--keep-base", "--onto");
1244                 if (options.root)
1245                         die(_("options '%s' and '%s' cannot be used together"), "--keep-base", "--root");
1246                 /*
1247                  * --keep-base defaults to --no-fork-point to keep the
1248                  * base the same.
1249                  */
1250                 if (options.fork_point < 0)
1251                         options.fork_point = 0;
1252         }
1253         if (options.root && options.fork_point > 0)
1254                 die(_("options '%s' and '%s' cannot be used together"), "--root", "--fork-point");
1255
1256         if (options.action != ACTION_NONE && !in_progress)
1257                 die(_("No rebase in progress?"));
1258
1259         if (options.action == ACTION_EDIT_TODO && !is_merge(&options))
1260                 die(_("The --edit-todo action can only be used during "
1261                       "interactive rebase."));
1262
1263         if (trace2_is_enabled()) {
1264                 if (is_merge(&options))
1265                         trace2_cmd_mode("interactive");
1266                 else if (options.exec.nr)
1267                         trace2_cmd_mode("interactive-exec");
1268                 else
1269                         trace2_cmd_mode(action_names[options.action]);
1270         }
1271
1272         options.reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1273         options.reflog_action =
1274                 xstrdup(options.reflog_action ? options.reflog_action : "rebase");
1275
1276         switch (options.action) {
1277         case ACTION_CONTINUE: {
1278                 struct object_id head;
1279                 struct lock_file lock_file = LOCK_INIT;
1280                 int fd;
1281
1282                 /* Sanity check */
1283                 if (repo_get_oid(the_repository, "HEAD", &head))
1284                         die(_("Cannot read HEAD"));
1285
1286                 fd = repo_hold_locked_index(the_repository, &lock_file, 0);
1287                 if (repo_read_index(the_repository) < 0)
1288                         die(_("could not read index"));
1289                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1290                               NULL);
1291                 if (0 <= fd)
1292                         repo_update_index_if_able(the_repository, &lock_file);
1293                 rollback_lock_file(&lock_file);
1294
1295                 if (has_unstaged_changes(the_repository, 1)) {
1296                         puts(_("You must edit all merge conflicts and then\n"
1297                                "mark them as resolved using git add"));
1298                         exit(1);
1299                 }
1300                 if (read_basic_state(&options))
1301                         exit(1);
1302                 goto run_rebase;
1303         }
1304         case ACTION_SKIP: {
1305                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1306
1307                 rerere_clear(the_repository, &merge_rr);
1308                 string_list_clear(&merge_rr, 1);
1309                 ropts.flags = RESET_HEAD_HARD;
1310                 if (reset_head(the_repository, &ropts) < 0)
1311                         die(_("could not discard worktree changes"));
1312                 remove_branch_state(the_repository, 0);
1313                 if (read_basic_state(&options))
1314                         exit(1);
1315                 goto run_rebase;
1316         }
1317         case ACTION_ABORT: {
1318                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1319                 struct strbuf head_msg = STRBUF_INIT;
1320
1321                 rerere_clear(the_repository, &merge_rr);
1322                 string_list_clear(&merge_rr, 1);
1323
1324                 if (read_basic_state(&options))
1325                         exit(1);
1326
1327                 strbuf_addf(&head_msg, "%s (abort): returning to %s",
1328                             options.reflog_action,
1329                             options.head_name ? options.head_name
1330                                               : oid_to_hex(&options.orig_head->object.oid));
1331                 ropts.oid = &options.orig_head->object.oid;
1332                 ropts.head_msg = head_msg.buf;
1333                 ropts.branch = options.head_name;
1334                 ropts.flags = RESET_HEAD_HARD;
1335                 if (reset_head(the_repository, &ropts) < 0)
1336                         die(_("could not move back to %s"),
1337                             oid_to_hex(&options.orig_head->object.oid));
1338                 strbuf_release(&head_msg);
1339                 remove_branch_state(the_repository, 0);
1340                 ret = finish_rebase(&options);
1341                 goto cleanup;
1342         }
1343         case ACTION_QUIT: {
1344                 save_autostash(state_dir_path("autostash", &options));
1345                 if (options.type == REBASE_MERGE) {
1346                         struct replay_opts replay = REPLAY_OPTS_INIT;
1347
1348                         replay.action = REPLAY_INTERACTIVE_REBASE;
1349                         ret = sequencer_remove_state(&replay);
1350                         replay_opts_release(&replay);
1351                 } else {
1352                         strbuf_reset(&buf);
1353                         strbuf_addstr(&buf, options.state_dir);
1354                         ret = remove_dir_recursively(&buf, 0);
1355                         if (ret)
1356                                 error(_("could not remove '%s'"),
1357                                        options.state_dir);
1358                 }
1359                 goto cleanup;
1360         }
1361         case ACTION_EDIT_TODO:
1362                 options.dont_finish_rebase = 1;
1363                 goto run_rebase;
1364         case ACTION_SHOW_CURRENT_PATCH:
1365                 options.dont_finish_rebase = 1;
1366                 goto run_rebase;
1367         case ACTION_NONE:
1368                 break;
1369         default:
1370                 BUG("action: %d", options.action);
1371         }
1372
1373         /* Make sure no rebase is in progress */
1374         if (in_progress) {
1375                 const char *last_slash = strrchr(options.state_dir, '/');
1376                 const char *state_dir_base =
1377                         last_slash ? last_slash + 1 : options.state_dir;
1378                 const char *cmd_live_rebase =
1379                         "git rebase (--continue | --abort | --skip)";
1380                 strbuf_reset(&buf);
1381                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1382                 die(_("It seems that there is already a %s directory, and\n"
1383                       "I wonder if you are in the middle of another rebase.  "
1384                       "If that is the\n"
1385                       "case, please try\n\t%s\n"
1386                       "If that is not the case, please\n\t%s\n"
1387                       "and run me again.  I am stopping in case you still "
1388                       "have something\n"
1389                       "valuable there.\n"),
1390                     state_dir_base, cmd_live_rebase, buf.buf);
1391         }
1392
1393         if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
1394             (options.action != ACTION_NONE) ||
1395             (options.exec.nr > 0) ||
1396             options.autosquash == 1) {
1397                 allow_preemptive_ff = 0;
1398         }
1399         if (options.committer_date_is_author_date || options.ignore_date)
1400                 options.flags |= REBASE_FORCE;
1401
1402         for (i = 0; i < options.git_am_opts.nr; i++) {
1403                 const char *option = options.git_am_opts.v[i], *p;
1404                 if (!strcmp(option, "--whitespace=fix") ||
1405                     !strcmp(option, "--whitespace=strip"))
1406                         allow_preemptive_ff = 0;
1407                 else if (skip_prefix(option, "-C", &p)) {
1408                         while (*p)
1409                                 if (!isdigit(*(p++)))
1410                                         die(_("switch `C' expects a "
1411                                               "numerical value"));
1412                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1413                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1414                             strcmp(p, "error") && strcmp(p, "error-all"))
1415                                 die("Invalid whitespace option: '%s'", p);
1416                 }
1417         }
1418
1419         for (i = 0; i < options.exec.nr; i++)
1420                 if (check_exec_cmd(options.exec.items[i].string))
1421                         exit(1);
1422
1423         if (!(options.flags & REBASE_NO_QUIET))
1424                 strvec_push(&options.git_am_opts, "-q");
1425
1426         if (options.empty != EMPTY_UNSPECIFIED)
1427                 imply_merge(&options, "--empty");
1428
1429         if (options.reapply_cherry_picks < 0)
1430                 /*
1431                  * We default to --no-reapply-cherry-picks unless
1432                  * --keep-base is given; when --keep-base is given, we want
1433                  * to default to --reapply-cherry-picks.
1434                  */
1435                 options.reapply_cherry_picks = keep_base;
1436         else if (!keep_base)
1437                 /*
1438                  * The apply backend always searches for and drops cherry
1439                  * picks.  This is often not wanted with --keep-base, so
1440                  * --keep-base allows --reapply-cherry-picks to be
1441                  * simulated by altering the upstream such that
1442                  * cherry-picks cannot be detected and thus all commits are
1443                  * reapplied.  Thus, --[no-]reapply-cherry-picks is
1444                  * supported when --keep-base is specified, but not when
1445                  * --keep-base is left out.
1446                  */
1447                 imply_merge(&options, options.reapply_cherry_picks ?
1448                                           "--reapply-cherry-picks" :
1449                                           "--no-reapply-cherry-picks");
1450
1451         if (gpg_sign)
1452                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1453
1454         if (options.exec.nr)
1455                 imply_merge(&options, "--exec");
1456
1457         if (options.type == REBASE_APPLY) {
1458                 if (ignore_whitespace)
1459                         strvec_push(&options.git_am_opts,
1460                                     "--ignore-whitespace");
1461                 if (options.committer_date_is_author_date)
1462                         strvec_push(&options.git_am_opts,
1463                                     "--committer-date-is-author-date");
1464                 if (options.ignore_date)
1465                         strvec_push(&options.git_am_opts, "--ignore-date");
1466         } else {
1467                 /* REBASE_MERGE */
1468                 if (ignore_whitespace) {
1469                         string_list_append(&options.strategy_opts,
1470                                            "ignore-space-change");
1471                 }
1472         }
1473
1474         if (options.strategy_opts.nr && !options.strategy)
1475                 options.strategy = "ort";
1476
1477         if (options.strategy) {
1478                 options.strategy = xstrdup(options.strategy);
1479                 imply_merge(&options, "--strategy");
1480         }
1481
1482         if (options.root && !options.onto_name)
1483                 imply_merge(&options, "--root without --onto");
1484
1485         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1486                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1487
1488         if (options.git_am_opts.nr || options.type == REBASE_APPLY) {
1489                 /* all am options except -q are compatible only with --apply */
1490                 for (i = options.git_am_opts.nr - 1; i >= 0; i--)
1491                         if (strcmp(options.git_am_opts.v[i], "-q"))
1492                                 break;
1493
1494                 if (i >= 0 || options.type == REBASE_APPLY) {
1495                         if (is_merge(&options))
1496                                 die(_("apply options and merge options "
1497                                           "cannot be used together"));
1498                         else if (options.rebase_merges == -1 && options.config_rebase_merges == 1)
1499                                 die(_("apply options are incompatible with rebase.rebaseMerges.  Consider adding --no-rebase-merges"));
1500                         else if (options.update_refs == -1 && options.config_update_refs == 1)
1501                                 die(_("apply options are incompatible with rebase.updateRefs.  Consider adding --no-update-refs"));
1502                         else
1503                                 options.type = REBASE_APPLY;
1504                 }
1505         }
1506
1507         if (options.update_refs == 1)
1508                 imply_merge(&options, "--update-refs");
1509         options.update_refs = (options.update_refs >= 0) ? options.update_refs :
1510                              ((options.config_update_refs >= 0) ? options.config_update_refs : 0);
1511
1512         if (options.rebase_merges == 1)
1513                 imply_merge(&options, "--rebase-merges");
1514         options.rebase_merges = (options.rebase_merges >= 0) ? options.rebase_merges :
1515                                 ((options.config_rebase_merges >= 0) ? options.config_rebase_merges : 0);
1516
1517         if (options.autosquash == 1) {
1518                 imply_merge(&options, "--autosquash");
1519         } else if (options.autosquash == -1) {
1520                 options.autosquash =
1521                         options.config_autosquash &&
1522                         (options.flags & REBASE_INTERACTIVE_EXPLICIT);
1523         }
1524
1525         if (options.type == REBASE_UNSPECIFIED) {
1526                 if (!strcmp(options.default_backend, "merge"))
1527                         options.type = REBASE_MERGE;
1528                 else if (!strcmp(options.default_backend, "apply"))
1529                         options.type = REBASE_APPLY;
1530                 else
1531                         die(_("Unknown rebase backend: %s"),
1532                             options.default_backend);
1533         }
1534
1535         if (options.type == REBASE_MERGE &&
1536             !options.strategy &&
1537             getenv("GIT_TEST_MERGE_ALGORITHM"))
1538                 options.strategy = xstrdup(getenv("GIT_TEST_MERGE_ALGORITHM"));
1539
1540         switch (options.type) {
1541         case REBASE_MERGE:
1542                 options.state_dir = merge_dir();
1543                 break;
1544         case REBASE_APPLY:
1545                 options.state_dir = apply_dir();
1546                 break;
1547         default:
1548                 BUG("options.type was just set above; should be unreachable.");
1549         }
1550
1551         if (options.empty == EMPTY_UNSPECIFIED) {
1552                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1553                         options.empty = EMPTY_ASK;
1554                 else if (options.exec.nr > 0)
1555                         options.empty = EMPTY_KEEP;
1556                 else
1557                         options.empty = EMPTY_DROP;
1558         }
1559         if (reschedule_failed_exec > 0 && !is_merge(&options))
1560                 die(_("--reschedule-failed-exec requires "
1561                       "--exec or --interactive"));
1562         if (reschedule_failed_exec >= 0)
1563                 options.reschedule_failed_exec = reschedule_failed_exec;
1564
1565         if (options.signoff) {
1566                 strvec_push(&options.git_am_opts, "--signoff");
1567                 options.flags |= REBASE_FORCE;
1568         }
1569
1570         if (!options.root) {
1571                 if (argc < 1) {
1572                         struct branch *branch;
1573
1574                         branch = branch_get(NULL);
1575                         options.upstream_name = branch_get_upstream(branch,
1576                                                                     NULL);
1577                         if (!options.upstream_name)
1578                                 error_on_missing_default_upstream();
1579                         if (options.fork_point < 0)
1580                                 options.fork_point = 1;
1581                 } else {
1582                         options.upstream_name = argv[0];
1583                         argc--;
1584                         argv++;
1585                         if (!strcmp(options.upstream_name, "-"))
1586                                 options.upstream_name = "@{-1}";
1587                 }
1588                 options.upstream =
1589                         lookup_commit_reference_by_name(options.upstream_name);
1590                 if (!options.upstream)
1591                         die(_("invalid upstream '%s'"), options.upstream_name);
1592                 options.upstream_arg = options.upstream_name;
1593         } else {
1594                 if (!options.onto_name) {
1595                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1596                                         &squash_onto, NULL, NULL) < 0)
1597                                 die(_("Could not create new root commit"));
1598                         options.squash_onto = &squash_onto;
1599                         options.onto_name = squash_onto_name =
1600                                 xstrdup(oid_to_hex(&squash_onto));
1601                 } else
1602                         options.root_with_onto = 1;
1603
1604                 options.upstream_name = NULL;
1605                 options.upstream = NULL;
1606                 if (argc > 1)
1607                         usage_with_options(builtin_rebase_usage,
1608                                            builtin_rebase_options);
1609                 options.upstream_arg = "--root";
1610         }
1611
1612         /*
1613          * If the branch to rebase is given, that is the branch we will rebase
1614          * branch_name -- branch/commit being rebased, or
1615          *                HEAD (already detached)
1616          * orig_head -- commit object name of tip of the branch before rebasing
1617          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1618          */
1619         if (argc == 1) {
1620                 /* Is it "rebase other branchname" or "rebase other commit"? */
1621                 struct object_id branch_oid;
1622                 branch_name = argv[0];
1623                 options.switch_to = argv[0];
1624
1625                 /* Is it a local branch? */
1626                 strbuf_reset(&buf);
1627                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1628                 if (!read_ref(buf.buf, &branch_oid)) {
1629                         die_if_checked_out(buf.buf, 1);
1630                         options.head_name = xstrdup(buf.buf);
1631                         options.orig_head =
1632                                 lookup_commit_object(the_repository,
1633                                                      &branch_oid);
1634                 /* If not is it a valid ref (branch or commit)? */
1635                 } else {
1636                         options.orig_head =
1637                                 lookup_commit_reference_by_name(branch_name);
1638                         options.head_name = NULL;
1639                 }
1640                 if (!options.orig_head)
1641                         die(_("no such branch/commit '%s'"), branch_name);
1642         } else if (argc == 0) {
1643                 /* Do not need to switch branches, we are already on it. */
1644                 options.head_name =
1645                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1646                                          &flags));
1647                 if (!options.head_name)
1648                         die(_("No such ref: %s"), "HEAD");
1649                 if (flags & REF_ISSYMREF) {
1650                         if (!skip_prefix(options.head_name,
1651                                          "refs/heads/", &branch_name))
1652                                 branch_name = options.head_name;
1653
1654                 } else {
1655                         FREE_AND_NULL(options.head_name);
1656                         branch_name = "HEAD";
1657                 }
1658                 options.orig_head = lookup_commit_reference_by_name("HEAD");
1659                 if (!options.orig_head)
1660                         die(_("Could not resolve HEAD to a commit"));
1661         } else
1662                 BUG("unexpected number of arguments left to parse");
1663
1664         /* Make sure the branch to rebase onto is valid. */
1665         if (keep_base) {
1666                 strbuf_reset(&buf);
1667                 strbuf_addstr(&buf, options.upstream_name);
1668                 strbuf_addstr(&buf, "...");
1669                 strbuf_addstr(&buf, branch_name);
1670                 options.onto_name = keep_base_onto_name = xstrdup(buf.buf);
1671         } else if (!options.onto_name)
1672                 options.onto_name = options.upstream_name;
1673         if (strstr(options.onto_name, "...")) {
1674                 if (repo_get_oid_mb(the_repository, options.onto_name, &branch_base) < 0) {
1675                         if (keep_base)
1676                                 die(_("'%s': need exactly one merge base with branch"),
1677                                     options.upstream_name);
1678                         else
1679                                 die(_("'%s': need exactly one merge base"),
1680                                     options.onto_name);
1681                 }
1682                 options.onto = lookup_commit_or_die(&branch_base,
1683                                                     options.onto_name);
1684         } else {
1685                 options.onto =
1686                         lookup_commit_reference_by_name(options.onto_name);
1687                 if (!options.onto)
1688                         die(_("Does not point to a valid commit '%s'"),
1689                                 options.onto_name);
1690                 fill_branch_base(&options, &branch_base);
1691         }
1692
1693         if (keep_base && options.reapply_cherry_picks)
1694                 options.upstream = options.onto;
1695
1696         if (options.fork_point > 0)
1697                 options.restrict_revision =
1698                         get_fork_point(options.upstream_name, options.orig_head);
1699
1700         if (repo_read_index(the_repository) < 0)
1701                 die(_("could not read index"));
1702
1703         if (options.autostash)
1704                 create_autostash(the_repository,
1705                                  state_dir_path("autostash", &options));
1706
1707
1708         if (require_clean_work_tree(the_repository, "rebase",
1709                                     _("Please commit or stash them."), 1, 1)) {
1710                 ret = -1;
1711                 goto cleanup;
1712         }
1713
1714         /*
1715          * Now we are rebasing commits upstream..orig_head (or with --root,
1716          * everything leading up to orig_head) on top of onto.
1717          */
1718
1719         /*
1720          * Check if we are already based on onto with linear history,
1721          * in which case we could fast-forward without replacing the commits
1722          * with new commits recreated by replaying their changes.
1723          */
1724         if (allow_preemptive_ff &&
1725             can_fast_forward(options.onto, options.upstream, options.restrict_revision,
1726                              options.orig_head, &branch_base)) {
1727                 int flag;
1728
1729                 if (!(options.flags & REBASE_FORCE)) {
1730                         /* Lazily switch to the target branch if needed... */
1731                         if (options.switch_to) {
1732                                 ret = checkout_up_to_date(&options);
1733                                 if (ret)
1734                                         goto cleanup;
1735                         }
1736
1737                         if (!(options.flags & REBASE_NO_QUIET))
1738                                 ; /* be quiet */
1739                         else if (!strcmp(branch_name, "HEAD") &&
1740                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1741                                 puts(_("HEAD is up to date."));
1742                         else
1743                                 printf(_("Current branch %s is up to date.\n"),
1744                                        branch_name);
1745                         ret = finish_rebase(&options);
1746                         goto cleanup;
1747                 } else if (!(options.flags & REBASE_NO_QUIET))
1748                         ; /* be quiet */
1749                 else if (!strcmp(branch_name, "HEAD") &&
1750                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1751                         puts(_("HEAD is up to date, rebase forced."));
1752                 else
1753                         printf(_("Current branch %s is up to date, rebase "
1754                                  "forced.\n"), branch_name);
1755         }
1756
1757         /* If a hook exists, give it a chance to interrupt*/
1758         if (!ok_to_skip_pre_rebase &&
1759             run_hooks_l("pre-rebase", options.upstream_arg,
1760                         argc ? argv[0] : NULL, NULL))
1761                 die(_("The pre-rebase hook refused to rebase."));
1762
1763         if (options.flags & REBASE_DIFFSTAT) {
1764                 struct diff_options opts;
1765
1766                 if (options.flags & REBASE_VERBOSE) {
1767                         if (is_null_oid(&branch_base))
1768                                 printf(_("Changes to %s:\n"),
1769                                        oid_to_hex(&options.onto->object.oid));
1770                         else
1771                                 printf(_("Changes from %s to %s:\n"),
1772                                        oid_to_hex(&branch_base),
1773                                        oid_to_hex(&options.onto->object.oid));
1774                 }
1775
1776                 /* We want color (if set), but no pager */
1777                 repo_diff_setup(the_repository, &opts);
1778                 init_diffstat_widths(&opts);
1779                 opts.output_format |=
1780                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1781                 opts.detect_rename = DIFF_DETECT_RENAME;
1782                 diff_setup_done(&opts);
1783                 diff_tree_oid(is_null_oid(&branch_base) ?
1784                               the_hash_algo->empty_tree : &branch_base,
1785                               &options.onto->object.oid, "", &opts);
1786                 diffcore_std(&opts);
1787                 diff_flush(&opts);
1788         }
1789
1790         if (is_merge(&options))
1791                 goto run_rebase;
1792
1793         /* Detach HEAD and reset the tree */
1794         if (options.flags & REBASE_NO_QUIET)
1795                 printf(_("First, rewinding head to replay your work on top of "
1796                          "it...\n"));
1797
1798         strbuf_addf(&msg, "%s (start): checkout %s",
1799                     options.reflog_action, options.onto_name);
1800         ropts.oid = &options.onto->object.oid;
1801         ropts.orig_head = &options.orig_head->object.oid,
1802         ropts.flags = RESET_HEAD_DETACH | RESET_ORIG_HEAD |
1803                         RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
1804         ropts.head_msg = msg.buf;
1805         ropts.default_reflog_action = options.reflog_action;
1806         if (reset_head(the_repository, &ropts))
1807                 die(_("Could not detach HEAD"));
1808         strbuf_release(&msg);
1809
1810         /*
1811          * If the onto is a proper descendant of the tip of the branch, then
1812          * we just fast-forwarded.
1813          */
1814         if (oideq(&branch_base, &options.orig_head->object.oid)) {
1815                 printf(_("Fast-forwarded %s to %s.\n"),
1816                         branch_name, options.onto_name);
1817                 move_to_original_branch(&options);
1818                 ret = finish_rebase(&options);
1819                 goto cleanup;
1820         }
1821
1822         strbuf_addf(&revisions, "%s..%s",
1823                     options.root ? oid_to_hex(&options.onto->object.oid) :
1824                     (options.restrict_revision ?
1825                      oid_to_hex(&options.restrict_revision->object.oid) :
1826                      oid_to_hex(&options.upstream->object.oid)),
1827                     oid_to_hex(&options.orig_head->object.oid));
1828
1829         options.revisions = revisions.buf;
1830
1831 run_rebase:
1832         ret = run_specific_rebase(&options);
1833
1834 cleanup:
1835         strbuf_release(&buf);
1836         strbuf_release(&revisions);
1837         free(options.reflog_action);
1838         free(options.head_name);
1839         strvec_clear(&options.git_am_opts);
1840         free(options.gpg_sign_opt);
1841         string_list_clear(&options.exec, 0);
1842         free(options.strategy);
1843         string_list_clear(&options.strategy_opts, 0);
1844         strbuf_release(&options.git_format_patch_opt);
1845         free(squash_onto_name);
1846         free(keep_base_onto_name);
1847         return !!ret;
1848 }