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