git.oblomov.eu Git - git/blob - builtin/rebase.c

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   8 #include "builtin.h"
   9 #include "run-command.h"
  10 #include "exec-cmd.h"
  11 #include "argv-array.h"
  12 #include "dir.h"
  13 #include "packfile.h"
  14 #include "refs.h"
  15 #include "quote.h"
  16 #include "config.h"
  17 #include "cache-tree.h"
  18 #include "unpack-trees.h"
  19 #include "lockfile.h"
  20 #include "parse-options.h"
  21 #include "commit.h"
  22 #include "diff.h"
  23 #include "wt-status.h"
  24 #include "revision.h"
  25 #include "commit-reach.h"
  26 #include "rerere.h"
  27 #include "branch.h"
  28 #include "sequencer.h"
  29 #include "rebase-interactive.h"
  30
  31 static char const * const builtin_rebase_usage[] = {
  32         N_("git rebase [-i] [options] [--exec <cmd>] "
  33                 "[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
  34         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  35                 "--root [<branch>]"),
  36         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  37         NULL
  38 };
  39
  40 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
  41 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
  42 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  43 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  44
  45 enum rebase_type {
  46         REBASE_UNSPECIFIED = -1,
  47         REBASE_AM,
  48         REBASE_MERGE,
  49         REBASE_INTERACTIVE,
  50         REBASE_PRESERVE_MERGES
  51 };
  52
  53 enum empty_type {
  54         EMPTY_UNSPECIFIED = -1,
  55         EMPTY_DROP,
  56         EMPTY_KEEP,
  57         EMPTY_ASK
  58 };
  59
  60 struct rebase_options {
  61         enum rebase_type type;
  62         enum empty_type empty;
  63         const char *state_dir;
  64         struct commit *upstream;
  65         const char *upstream_name;
  66         const char *upstream_arg;
  67         char *head_name;
  68         struct object_id orig_head;
  69         struct commit *onto;
  70         const char *onto_name;
  71         const char *revisions;
  72         const char *switch_to;
  73         int root, root_with_onto;
  74         struct object_id *squash_onto;
  75         struct commit *restrict_revision;
  76         int dont_finish_rebase;
  77         enum {
  78                 REBASE_NO_QUIET = 1<<0,
  79                 REBASE_VERBOSE = 1<<1,
  80                 REBASE_DIFFSTAT = 1<<2,
  81                 REBASE_FORCE = 1<<3,
  82                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  83         } flags;
  84         struct argv_array git_am_opts;
  85         const char *action;
  86         int signoff;
  87         int allow_rerere_autoupdate;
  88         int autosquash;
  89         char *gpg_sign_opt;
  90         int autostash;
  91         char *cmd;
  92         int allow_empty_message;
  93         int rebase_merges, rebase_cousins;
  94         char *strategy, *strategy_opts;
  95         struct strbuf git_format_patch_opt;
  96         int reschedule_failed_exec;
  97         int use_legacy_rebase;
  98 };
  99
 100 #define REBASE_OPTIONS_INIT {                           \
 101                 .type = REBASE_UNSPECIFIED,             \
 102                 .empty = EMPTY_UNSPECIFIED,             \
 103                 .flags = REBASE_NO_QUIET,               \
 104                 .git_am_opts = ARGV_ARRAY_INIT,         \
 105                 .git_format_patch_opt = STRBUF_INIT     \
 106         }
 107
 108 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 109 {
 110         struct replay_opts replay = REPLAY_OPTS_INIT;
 111
 112         replay.action = REPLAY_INTERACTIVE_REBASE;
 113         sequencer_init_config(&replay);
 114
 115         replay.signoff = opts->signoff;
 116         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 117         if (opts->allow_rerere_autoupdate)
 118                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 119         replay.allow_empty = 1;
 120         replay.allow_empty_message = opts->allow_empty_message;
 121         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
 122         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
 123         replay.verbose = opts->flags & REBASE_VERBOSE;
 124         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 125         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 126         replay.strategy = opts->strategy;
 127         if (opts->strategy_opts)
 128                 parse_strategy_opts(&replay, opts->strategy_opts);
 129
 130         if (opts->squash_onto) {
 131                 oidcpy(&replay.squash_onto, opts->squash_onto);
 132                 replay.have_squash_onto = 1;
 133         }
 134
 135         return replay;
 136 }
 137
 138 enum action {
 139         ACTION_NONE = 0,
 140         ACTION_CONTINUE,
 141         ACTION_SKIP,
 142         ACTION_ABORT,
 143         ACTION_QUIT,
 144         ACTION_EDIT_TODO,
 145         ACTION_SHOW_CURRENT_PATCH,
 146         ACTION_SHORTEN_OIDS,
 147         ACTION_EXPAND_OIDS,
 148         ACTION_CHECK_TODO_LIST,
 149         ACTION_REARRANGE_SQUASH,
 150         ACTION_ADD_EXEC
 151 };
 152
 153 static const char *action_names[] = { "undefined",
 154                                       "continue",
 155                                       "skip",
 156                                       "abort",
 157                                       "quit",
 158                                       "edit_todo",
 159                                       "show_current_patch" };
 160
 161 static int add_exec_commands(struct string_list *commands)
 162 {
 163         const char *todo_file = rebase_path_todo();
 164         struct todo_list todo_list = TODO_LIST_INIT;
 165         int res;
 166
 167         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 168                 return error_errno(_("could not read '%s'."), todo_file);
 169
 170         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 171                                         &todo_list)) {
 172                 todo_list_release(&todo_list);
 173                 return error(_("unusable todo list: '%s'"), todo_file);
 174         }
 175
 176         todo_list_add_exec_commands(&todo_list, commands);
 177         res = todo_list_write_to_file(the_repository, &todo_list,
 178                                       todo_file, NULL, NULL, -1, 0);
 179         todo_list_release(&todo_list);
 180
 181         if (res)
 182                 return error_errno(_("could not write '%s'."), todo_file);
 183         return 0;
 184 }
 185
 186 static int rearrange_squash_in_todo_file(void)
 187 {
 188         const char *todo_file = rebase_path_todo();
 189         struct todo_list todo_list = TODO_LIST_INIT;
 190         int res = 0;
 191
 192         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 193                 return error_errno(_("could not read '%s'."), todo_file);
 194         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 195                                         &todo_list)) {
 196                 todo_list_release(&todo_list);
 197                 return error(_("unusable todo list: '%s'"), todo_file);
 198         }
 199
 200         res = todo_list_rearrange_squash(&todo_list);
 201         if (!res)
 202                 res = todo_list_write_to_file(the_repository, &todo_list,
 203                                               todo_file, NULL, NULL, -1, 0);
 204
 205         todo_list_release(&todo_list);
 206
 207         if (res)
 208                 return error_errno(_("could not write '%s'."), todo_file);
 209         return 0;
 210 }
 211
 212 static int transform_todo_file(unsigned flags)
 213 {
 214         const char *todo_file = rebase_path_todo();
 215         struct todo_list todo_list = TODO_LIST_INIT;
 216         int res;
 217
 218         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 219                 return error_errno(_("could not read '%s'."), todo_file);
 220
 221         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 222                                         &todo_list)) {
 223                 todo_list_release(&todo_list);
 224                 return error(_("unusable todo list: '%s'"), todo_file);
 225         }
 226
 227         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 228                                       NULL, NULL, -1, flags);
 229         todo_list_release(&todo_list);
 230
 231         if (res)
 232                 return error_errno(_("could not write '%s'."), todo_file);
 233         return 0;
 234 }
 235
 236 static int edit_todo_file(unsigned flags)
 237 {
 238         const char *todo_file = rebase_path_todo();
 239         struct todo_list todo_list = TODO_LIST_INIT,
 240                 new_todo = TODO_LIST_INIT;
 241         int res = 0;
 242
 243         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 244                 return error_errno(_("could not read '%s'."), todo_file);
 245
 246         strbuf_stripspace(&todo_list.buf, 1);
 247         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 248         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 249                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 250                 res = error_errno(_("could not write '%s'"), todo_file);
 251
 252         todo_list_release(&todo_list);
 253         todo_list_release(&new_todo);
 254
 255         return res;
 256 }
 257
 258 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 259                                const char **head_hash,
 260                                char **revisions, char **shortrevisions)
 261 {
 262         struct commit *base_rev = upstream ? upstream : onto;
 263         const char *shorthead;
 264         struct object_id orig_head;
 265
 266         if (get_oid("HEAD", &orig_head))
 267                 return error(_("no HEAD?"));
 268
 269         *head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
 270         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 271                                                    *head_hash);
 272
 273         shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
 274
 275         if (upstream) {
 276                 const char *shortrev;
 277
 278                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 279                                               DEFAULT_ABBREV);
 280
 281                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 282         } else
 283                 *shortrevisions = xstrdup(shorthead);
 284
 285         return 0;
 286 }
 287
 288 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 289                             struct commit *onto, const char *orig_head)
 290 {
 291         FILE *interactive;
 292
 293         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 294                 return error_errno(_("could not create temporary %s"), merge_dir());
 295
 296         delete_reflog("REBASE_HEAD");
 297
 298         interactive = fopen(path_interactive(), "w");
 299         if (!interactive)
 300                 return error_errno(_("could not mark as interactive"));
 301         fclose(interactive);
 302
 303         return write_basic_state(opts, head_name, onto, orig_head);
 304 }
 305
 306 static void split_exec_commands(const char *cmd, struct string_list *commands)
 307 {
 308         if (cmd && *cmd) {
 309                 string_list_split(commands, cmd, '\n', -1);
 310
 311                 /* rebase.c adds a new line to cmd after every command,
 312                  * so here the last command is always empty */
 313                 string_list_remove_empty_items(commands, 0);
 314         }
 315 }
 316
 317 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 318 {
 319         int ret;
 320         const char *head_hash = NULL;
 321         char *revisions = NULL, *shortrevisions = NULL;
 322         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 323         struct todo_list todo_list = TODO_LIST_INIT;
 324         struct replay_opts replay = get_replay_opts(opts);
 325         struct string_list commands = STRING_LIST_INIT_DUP;
 326
 327         if (prepare_branch_to_be_rebased(the_repository, &replay,
 328                                          opts->switch_to))
 329                 return -1;
 330
 331         if (get_revision_ranges(opts->upstream, opts->onto, &head_hash,
 332                                 &revisions, &shortrevisions))
 333                 return -1;
 334
 335         if (init_basic_state(&replay,
 336                              opts->head_name ? opts->head_name : "detached HEAD",
 337                              opts->onto, head_hash)) {
 338                 free(revisions);
 339                 free(shortrevisions);
 340
 341                 return -1;
 342         }
 343
 344         if (!opts->upstream && opts->squash_onto)
 345                 write_file(path_squash_onto(), "%s\n",
 346                            oid_to_hex(opts->squash_onto));
 347
 348         argv_array_pushl(&make_script_args, "", revisions, NULL);
 349         if (opts->restrict_revision)
 350                 argv_array_push(&make_script_args,
 351                                 oid_to_hex(&opts->restrict_revision->object.oid));
 352
 353         ret = sequencer_make_script(the_repository, &todo_list.buf,
 354                                     make_script_args.argc, make_script_args.argv,
 355                                     flags);
 356
 357         if (ret)
 358                 error(_("could not generate todo list"));
 359         else {
 360                 discard_cache();
 361                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 362                                                 &todo_list))
 363                         BUG("unusable todo list");
 364
 365                 split_exec_commands(opts->cmd, &commands);
 366                 ret = complete_action(the_repository, &replay, flags,
 367                         shortrevisions, opts->onto_name, opts->onto, head_hash,
 368                         &commands, opts->autosquash, &todo_list);
 369         }
 370
 371         string_list_clear(&commands, 0);
 372         free(revisions);
 373         free(shortrevisions);
 374         todo_list_release(&todo_list);
 375         argv_array_clear(&make_script_args);
 376
 377         return ret;
 378 }
 379
 380 static int run_rebase_interactive(struct rebase_options *opts,
 381                                   enum action command)
 382 {
 383         unsigned flags = 0;
 384         int abbreviate_commands = 0, ret = 0;
 385
 386         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 387
 388         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 389         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 390         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 391         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 392         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 393
 394         switch (command) {
 395         case ACTION_NONE: {
 396                 if (!opts->onto && !opts->upstream)
 397                         die(_("a base commit must be provided with --upstream or --onto"));
 398
 399                 ret = do_interactive_rebase(opts, flags);
 400                 break;
 401         }
 402         case ACTION_SKIP: {
 403                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 404
 405                 rerere_clear(the_repository, &merge_rr);
 406         }
 407                 /* fallthrough */
 408         case ACTION_CONTINUE: {
 409                 struct replay_opts replay_opts = get_replay_opts(opts);
 410
 411                 ret = sequencer_continue(the_repository, &replay_opts);
 412                 break;
 413         }
 414         case ACTION_EDIT_TODO:
 415                 ret = edit_todo_file(flags);
 416                 break;
 417         case ACTION_SHOW_CURRENT_PATCH: {
 418                 struct child_process cmd = CHILD_PROCESS_INIT;
 419
 420                 cmd.git_cmd = 1;
 421                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 422                 ret = run_command(&cmd);
 423
 424                 break;
 425         }
 426         case ACTION_SHORTEN_OIDS:
 427         case ACTION_EXPAND_OIDS:
 428                 ret = transform_todo_file(flags);
 429                 break;
 430         case ACTION_CHECK_TODO_LIST:
 431                 ret = check_todo_list_from_file(the_repository);
 432                 break;
 433         case ACTION_REARRANGE_SQUASH:
 434                 ret = rearrange_squash_in_todo_file();
 435                 break;
 436         case ACTION_ADD_EXEC: {
 437                 struct string_list commands = STRING_LIST_INIT_DUP;
 438
 439                 split_exec_commands(opts->cmd, &commands);
 440                 ret = add_exec_commands(&commands);
 441                 string_list_clear(&commands, 0);
 442                 break;
 443         }
 444         default:
 445                 BUG("invalid command '%d'", command);
 446         }
 447
 448         return ret;
 449 }
 450
 451 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 452                                 int unset)
 453 {
 454         struct rebase_options *opts = opt->value;
 455
 456         BUG_ON_OPT_ARG(arg);
 457
 458         /*
 459          * If we ever want to remap --keep-empty to --empty=keep, insert:
 460          *      opts->empty = unset ? EMPTY_UNSPECIFIED : EMPTY_KEEP;
 461          */
 462         opts->type = REBASE_INTERACTIVE;
 463         return 0;
 464 }
 465
 466 static const char * const builtin_rebase_interactive_usage[] = {
 467         N_("git rebase--interactive [<options>]"),
 468         NULL
 469 };
 470
 471 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 472 {
 473         struct rebase_options opts = REBASE_OPTIONS_INIT;
 474         struct object_id squash_onto = null_oid;
 475         enum action command = ACTION_NONE;
 476         struct option options[] = {
 477                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 478                            REBASE_FORCE),
 479                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
 480                         N_("(DEPRECATED) keep empty commits"),
 481                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
 482                         parse_opt_keep_empty },
 483                 OPT_BOOL_F(0, "allow-empty-message", &opts.allow_empty_message,
 484                            N_("allow commits with empty messages"),
 485                            PARSE_OPT_HIDDEN),
 486                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 487                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 488                          N_("keep original branch points of cousins")),
 489                 OPT_BOOL(0, "autosquash", &opts.autosquash,
 490                          N_("move commits that begin with squash!/fixup!")),
 491                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 492                 OPT_BIT('v', "verbose", &opts.flags,
 493                         N_("display a diffstat of what changed upstream"),
 494                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 495                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 496                             ACTION_CONTINUE),
 497                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 498                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 499                             ACTION_EDIT_TODO),
 500                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 501                             ACTION_SHOW_CURRENT_PATCH),
 502                 OPT_CMDMODE(0, "shorten-ids", &command,
 503                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 504                 OPT_CMDMODE(0, "expand-ids", &command,
 505                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 506                 OPT_CMDMODE(0, "check-todo-list", &command,
 507                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 508                 OPT_CMDMODE(0, "rearrange-squash", &command,
 509                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 510                 OPT_CMDMODE(0, "add-exec-commands", &command,
 511                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 512                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 513                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 514                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 515                   N_("restrict-revision"), N_("restrict revision"),
 516                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 517                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 518                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 519                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 520                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 521                   0 },
 522                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 523                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 524                         N_("GPG-sign commits"),
 525                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 526                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 527                            N_("rebase strategy")),
 528                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 529                            N_("strategy options")),
 530                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 531                            N_("the branch or commit to checkout")),
 532                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 533                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 534                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 535                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 536                          N_("automatically re-schedule any `exec` that fails")),
 537                 OPT_END()
 538         };
 539
 540         opts.rebase_cousins = -1;
 541
 542         if (argc == 1)
 543                 usage_with_options(builtin_rebase_interactive_usage, options);
 544
 545         argc = parse_options(argc, argv, prefix, options,
 546                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 547
 548         if (!is_null_oid(&squash_onto))
 549                 opts.squash_onto = &squash_onto;
 550
 551         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 552                 warning(_("--[no-]rebase-cousins has no effect without "
 553                           "--rebase-merges"));
 554
 555         return !!run_rebase_interactive(&opts, command);
 556 }
 557
 558 static int is_interactive(struct rebase_options *opts)
 559 {
 560         return opts->type == REBASE_INTERACTIVE ||
 561                 opts->type == REBASE_PRESERVE_MERGES;
 562 }
 563
 564 static void imply_interactive(struct rebase_options *opts, const char *option)
 565 {
 566         switch (opts->type) {
 567         case REBASE_AM:
 568                 die(_("%s requires an interactive rebase"), option);
 569                 break;
 570         case REBASE_INTERACTIVE:
 571         case REBASE_PRESERVE_MERGES:
 572                 break;
 573         case REBASE_MERGE:
 574                 /* we now implement --merge via --interactive */
 575         default:
 576                 opts->type = REBASE_INTERACTIVE; /* implied */
 577                 break;
 578         }
 579 }
 580
 581 /* Returns the filename prefixed by the state_dir */
 582 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 583 {
 584         static struct strbuf path = STRBUF_INIT;
 585         static size_t prefix_len;
 586
 587         if (!prefix_len) {
 588                 strbuf_addf(&path, "%s/", opts->state_dir);
 589                 prefix_len = path.len;
 590         }
 591
 592         strbuf_setlen(&path, prefix_len);
 593         strbuf_addstr(&path, filename);
 594         return path.buf;
 595 }
 596
 597 /* Read one file, then strip line endings */
 598 static int read_one(const char *path, struct strbuf *buf)
 599 {
 600         if (strbuf_read_file(buf, path, 0) < 0)
 601                 return error_errno(_("could not read '%s'"), path);
 602         strbuf_trim_trailing_newline(buf);
 603         return 0;
 604 }
 605
 606 /* Initialize the rebase options from the state directory. */
 607 static int read_basic_state(struct rebase_options *opts)
 608 {
 609         struct strbuf head_name = STRBUF_INIT;
 610         struct strbuf buf = STRBUF_INIT;
 611         struct object_id oid;
 612
 613         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 614             read_one(state_dir_path("onto", opts), &buf))
 615                 return -1;
 616         opts->head_name = starts_with(head_name.buf, "refs/") ?
 617                 xstrdup(head_name.buf) : NULL;
 618         strbuf_release(&head_name);
 619         if (get_oid(buf.buf, &oid))
 620                 return error(_("could not get 'onto': '%s'"), buf.buf);
 621         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 622
 623         /*
 624          * We always write to orig-head, but interactive rebase used to write to
 625          * head. Fall back to reading from head to cover for the case that the
 626          * user upgraded git with an ongoing interactive rebase.
 627          */
 628         strbuf_reset(&buf);
 629         if (file_exists(state_dir_path("orig-head", opts))) {
 630                 if (read_one(state_dir_path("orig-head", opts), &buf))
 631                         return -1;
 632         } else if (read_one(state_dir_path("head", opts), &buf))
 633                 return -1;
 634         if (get_oid(buf.buf, &opts->orig_head))
 635                 return error(_("invalid orig-head: '%s'"), buf.buf);
 636
 637         if (file_exists(state_dir_path("quiet", opts)))
 638                 opts->flags &= ~REBASE_NO_QUIET;
 639         else
 640                 opts->flags |= REBASE_NO_QUIET;
 641
 642         if (file_exists(state_dir_path("verbose", opts)))
 643                 opts->flags |= REBASE_VERBOSE;
 644
 645         if (file_exists(state_dir_path("signoff", opts))) {
 646                 opts->signoff = 1;
 647                 opts->flags |= REBASE_FORCE;
 648         }
 649
 650         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 651                 strbuf_reset(&buf);
 652                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 653                             &buf))
 654                         return -1;
 655                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 656                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 657                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 658                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 659                 else
 660                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 661                                   "'%s'"), buf.buf);
 662         }
 663
 664         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 665                 strbuf_reset(&buf);
 666                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 667                             &buf))
 668                         return -1;
 669                 free(opts->gpg_sign_opt);
 670                 opts->gpg_sign_opt = xstrdup(buf.buf);
 671         }
 672
 673         if (file_exists(state_dir_path("strategy", opts))) {
 674                 strbuf_reset(&buf);
 675                 if (read_one(state_dir_path("strategy", opts), &buf))
 676                         return -1;
 677                 free(opts->strategy);
 678                 opts->strategy = xstrdup(buf.buf);
 679         }
 680
 681         if (file_exists(state_dir_path("strategy_opts", opts))) {
 682                 strbuf_reset(&buf);
 683                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 684                         return -1;
 685                 free(opts->strategy_opts);
 686                 opts->strategy_opts = xstrdup(buf.buf);
 687         }
 688
 689         strbuf_release(&buf);
 690
 691         return 0;
 692 }
 693
 694 static int rebase_write_basic_state(struct rebase_options *opts)
 695 {
 696         write_file(state_dir_path("head-name", opts), "%s",
 697                    opts->head_name ? opts->head_name : "detached HEAD");
 698         write_file(state_dir_path("onto", opts), "%s",
 699                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 700         write_file(state_dir_path("orig-head", opts), "%s",
 701                    oid_to_hex(&opts->orig_head));
 702         write_file(state_dir_path("quiet", opts), "%s",
 703                    opts->flags & REBASE_NO_QUIET ? "" : "t");
 704         if (opts->flags & REBASE_VERBOSE)
 705                 write_file(state_dir_path("verbose", opts), "%s", "");
 706         if (opts->strategy)
 707                 write_file(state_dir_path("strategy", opts), "%s",
 708                            opts->strategy);
 709         if (opts->strategy_opts)
 710                 write_file(state_dir_path("strategy_opts", opts), "%s",
 711                            opts->strategy_opts);
 712         if (opts->allow_rerere_autoupdate > 0)
 713                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 714                            "-%s-rerere-autoupdate",
 715                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 716                                 "" : "-no");
 717         if (opts->gpg_sign_opt)
 718                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 719                            opts->gpg_sign_opt);
 720         if (opts->signoff)
 721                 write_file(state_dir_path("signoff", opts), "--signoff");
 722
 723         return 0;
 724 }
 725
 726 static int apply_autostash(struct rebase_options *opts)
 727 {
 728         const char *path = state_dir_path("autostash", opts);
 729         struct strbuf autostash = STRBUF_INIT;
 730         struct child_process stash_apply = CHILD_PROCESS_INIT;
 731
 732         if (!file_exists(path))
 733                 return 0;
 734
 735         if (read_one(path, &autostash))
 736                 return error(_("Could not read '%s'"), path);
 737         /* Ensure that the hash is not mistaken for a number */
 738         strbuf_addstr(&autostash, "^0");
 739         argv_array_pushl(&stash_apply.args,
 740                          "stash", "apply", autostash.buf, NULL);
 741         stash_apply.git_cmd = 1;
 742         stash_apply.no_stderr = stash_apply.no_stdout =
 743                 stash_apply.no_stdin = 1;
 744         if (!run_command(&stash_apply))
 745                 printf(_("Applied autostash.\n"));
 746         else {
 747                 struct argv_array args = ARGV_ARRAY_INIT;
 748                 int res = 0;
 749
 750                 argv_array_pushl(&args,
 751                                  "stash", "store", "-m", "autostash", "-q",
 752                                  autostash.buf, NULL);
 753                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 754                         res = error(_("Cannot store %s"), autostash.buf);
 755                 argv_array_clear(&args);
 756                 strbuf_release(&autostash);
 757                 if (res)
 758                         return res;
 759
 760                 fprintf(stderr,
 761                         _("Applying autostash resulted in conflicts.\n"
 762                           "Your changes are safe in the stash.\n"
 763                           "You can run \"git stash pop\" or \"git stash drop\" "
 764                           "at any time.\n"));
 765         }
 766
 767         strbuf_release(&autostash);
 768         return 0;
 769 }
 770
 771 static int finish_rebase(struct rebase_options *opts)
 772 {
 773         struct strbuf dir = STRBUF_INIT;
 774         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 775         int ret = 0;
 776
 777         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 778         apply_autostash(opts);
 779         close_object_store(the_repository->objects);
 780         /*
 781          * We ignore errors in 'gc --auto', since the
 782          * user should see them.
 783          */
 784         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 785         if (opts->type == REBASE_INTERACTIVE) {
 786                 struct replay_opts replay = REPLAY_OPTS_INIT;
 787
 788                 replay.action = REPLAY_INTERACTIVE_REBASE;
 789                 ret = sequencer_remove_state(&replay);
 790         } else {
 791                 strbuf_addstr(&dir, opts->state_dir);
 792                 if (remove_dir_recursively(&dir, 0))
 793                         ret = error(_("could not remove '%s'"),
 794                                     opts->state_dir);
 795                 strbuf_release(&dir);
 796         }
 797
 798         return ret;
 799 }
 800
 801 static struct commit *peel_committish(const char *name)
 802 {
 803         struct object *obj;
 804         struct object_id oid;
 805
 806         if (get_oid(name, &oid))
 807                 return NULL;
 808         obj = parse_object(the_repository, &oid);
 809         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 810 }
 811
 812 static void add_var(struct strbuf *buf, const char *name, const char *value)
 813 {
 814         if (!value)
 815                 strbuf_addf(buf, "unset %s; ", name);
 816         else {
 817                 strbuf_addf(buf, "%s=", name);
 818                 sq_quote_buf(buf, value);
 819                 strbuf_addstr(buf, "; ");
 820         }
 821 }
 822
 823 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 824
 825 #define RESET_HEAD_DETACH (1<<0)
 826 #define RESET_HEAD_HARD (1<<1)
 827 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 828 #define RESET_HEAD_REFS_ONLY (1<<3)
 829 #define RESET_ORIG_HEAD (1<<4)
 830
 831 static int reset_head(struct object_id *oid, const char *action,
 832                       const char *switch_to_branch, unsigned flags,
 833                       const char *reflog_orig_head, const char *reflog_head)
 834 {
 835         unsigned detach_head = flags & RESET_HEAD_DETACH;
 836         unsigned reset_hard = flags & RESET_HEAD_HARD;
 837         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 838         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 839         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 840         struct object_id head_oid;
 841         struct tree_desc desc[2] = { { NULL }, { NULL } };
 842         struct lock_file lock = LOCK_INIT;
 843         struct unpack_trees_options unpack_tree_opts;
 844         struct tree *tree;
 845         const char *reflog_action;
 846         struct strbuf msg = STRBUF_INIT;
 847         size_t prefix_len;
 848         struct object_id *orig = NULL, oid_orig,
 849                 *old_orig = NULL, oid_old_orig;
 850         int ret = 0, nr = 0;
 851
 852         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 853                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 854
 855         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 856                 ret = -1;
 857                 goto leave_reset_head;
 858         }
 859
 860         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 861                 ret = error(_("could not determine HEAD revision"));
 862                 goto leave_reset_head;
 863         }
 864
 865         if (!oid)
 866                 oid = &head_oid;
 867
 868         if (refs_only)
 869                 goto reset_head_refs;
 870
 871         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 872         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 873         unpack_tree_opts.head_idx = 1;
 874         unpack_tree_opts.src_index = the_repository->index;
 875         unpack_tree_opts.dst_index = the_repository->index;
 876         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 877         unpack_tree_opts.update = 1;
 878         unpack_tree_opts.merge = 1;
 879         if (!detach_head)
 880                 unpack_tree_opts.reset = 1;
 881
 882         if (repo_read_index_unmerged(the_repository) < 0) {
 883                 ret = error(_("could not read index"));
 884                 goto leave_reset_head;
 885         }
 886
 887         if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 888                 ret = error(_("failed to find tree of %s"),
 889                             oid_to_hex(&head_oid));
 890                 goto leave_reset_head;
 891         }
 892
 893         if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 894                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 895                 goto leave_reset_head;
 896         }
 897
 898         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 899                 ret = -1;
 900                 goto leave_reset_head;
 901         }
 902
 903         tree = parse_tree_indirect(oid);
 904         prime_cache_tree(the_repository, the_repository->index, tree);
 905
 906         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 907                 ret = error(_("could not write index"));
 908                 goto leave_reset_head;
 909         }
 910
 911 reset_head_refs:
 912         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 913         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 914         prefix_len = msg.len;
 915
 916         if (update_orig_head) {
 917                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 918                         old_orig = &oid_old_orig;
 919                 if (!get_oid("HEAD", &oid_orig)) {
 920                         orig = &oid_orig;
 921                         if (!reflog_orig_head) {
 922                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 923                                 reflog_orig_head = msg.buf;
 924                         }
 925                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 926                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 927                 } else if (old_orig)
 928                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 929         }
 930
 931         if (!reflog_head) {
 932                 strbuf_setlen(&msg, prefix_len);
 933                 strbuf_addstr(&msg, "updating HEAD");
 934                 reflog_head = msg.buf;
 935         }
 936         if (!switch_to_branch)
 937                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 938                                  detach_head ? REF_NO_DEREF : 0,
 939                                  UPDATE_REFS_MSG_ON_ERR);
 940         else {
 941                 ret = update_ref(reflog_head, switch_to_branch, oid,
 942                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 943                 if (!ret)
 944                         ret = create_symref("HEAD", switch_to_branch,
 945                                             reflog_head);
 946         }
 947         if (run_hook)
 948                 run_hook_le(NULL, "post-checkout",
 949                             oid_to_hex(orig ? orig : &null_oid),
 950                             oid_to_hex(oid), "1", NULL);
 951
 952 leave_reset_head:
 953         strbuf_release(&msg);
 954         rollback_lock_file(&lock);
 955         while (nr)
 956                 free((void *)desc[--nr].buffer);
 957         return ret;
 958 }
 959
 960 static int move_to_original_branch(struct rebase_options *opts)
 961 {
 962         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 963         int ret;
 964
 965         if (!opts->head_name)
 966                 return 0; /* nothing to move back to */
 967
 968         if (!opts->onto)
 969                 BUG("move_to_original_branch without onto");
 970
 971         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 972                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 973         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 974                     opts->head_name);
 975         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 976                          orig_head_reflog.buf, head_reflog.buf);
 977
 978         strbuf_release(&orig_head_reflog);
 979         strbuf_release(&head_reflog);
 980         return ret;
 981 }
 982
 983 static const char *resolvemsg =
 984 N_("Resolve all conflicts manually, mark them as resolved with\n"
 985 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 986 "You can instead skip this commit: run \"git rebase --skip\".\n"
 987 "To abort and get back to the state before \"git rebase\", run "
 988 "\"git rebase --abort\".");
 989
 990 static int run_am(struct rebase_options *opts)
 991 {
 992         struct child_process am = CHILD_PROCESS_INIT;
 993         struct child_process format_patch = CHILD_PROCESS_INIT;
 994         struct strbuf revisions = STRBUF_INIT;
 995         int status;
 996         char *rebased_patches;
 997
 998         am.git_cmd = 1;
 999         argv_array_push(&am.args, "am");
1000
1001         if (opts->action && !strcmp("continue", opts->action)) {
1002                 argv_array_push(&am.args, "--resolved");
1003                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1004                 if (opts->gpg_sign_opt)
1005                         argv_array_push(&am.args, opts->gpg_sign_opt);
1006                 status = run_command(&am);
1007                 if (status)
1008                         return status;
1009
1010                 return move_to_original_branch(opts);
1011         }
1012         if (opts->action && !strcmp("skip", opts->action)) {
1013                 argv_array_push(&am.args, "--skip");
1014                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1015                 status = run_command(&am);
1016                 if (status)
1017                         return status;
1018
1019                 return move_to_original_branch(opts);
1020         }
1021         if (opts->action && !strcmp("show-current-patch", opts->action)) {
1022                 argv_array_push(&am.args, "--show-current-patch");
1023                 return run_command(&am);
1024         }
1025
1026         strbuf_addf(&revisions, "%s...%s",
1027                     oid_to_hex(opts->root ?
1028                                /* this is now equivalent to !opts->upstream */
1029                                &opts->onto->object.oid :
1030                                &opts->upstream->object.oid),
1031                     oid_to_hex(&opts->orig_head));
1032
1033         rebased_patches = xstrdup(git_path("rebased-patches"));
1034         format_patch.out = open(rebased_patches,
1035                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1036         if (format_patch.out < 0) {
1037                 status = error_errno(_("could not open '%s' for writing"),
1038                                      rebased_patches);
1039                 free(rebased_patches);
1040                 argv_array_clear(&am.args);
1041                 return status;
1042         }
1043
1044         format_patch.git_cmd = 1;
1045         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1046                          "--full-index", "--cherry-pick", "--right-only",
1047                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1048                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
1049                          "--no-base", NULL);
1050         if (opts->git_format_patch_opt.len)
1051                 argv_array_split(&format_patch.args,
1052                                  opts->git_format_patch_opt.buf);
1053         argv_array_push(&format_patch.args, revisions.buf);
1054         if (opts->restrict_revision)
1055                 argv_array_pushf(&format_patch.args, "^%s",
1056                                  oid_to_hex(&opts->restrict_revision->object.oid));
1057
1058         status = run_command(&format_patch);
1059         if (status) {
1060                 unlink(rebased_patches);
1061                 free(rebased_patches);
1062                 argv_array_clear(&am.args);
1063
1064                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1065                            "HEAD", NULL);
1066                 error(_("\ngit encountered an error while preparing the "
1067                         "patches to replay\n"
1068                         "these revisions:\n"
1069                         "\n    %s\n\n"
1070                         "As a result, git cannot rebase them."),
1071                       opts->revisions);
1072
1073                 strbuf_release(&revisions);
1074                 return status;
1075         }
1076         strbuf_release(&revisions);
1077
1078         am.in = open(rebased_patches, O_RDONLY);
1079         if (am.in < 0) {
1080                 status = error_errno(_("could not open '%s' for reading"),
1081                                      rebased_patches);
1082                 free(rebased_patches);
1083                 argv_array_clear(&am.args);
1084                 return status;
1085         }
1086
1087         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1088         argv_array_push(&am.args, "--rebasing");
1089         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1090         argv_array_push(&am.args, "--patch-format=mboxrd");
1091         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1092                 argv_array_push(&am.args, "--rerere-autoupdate");
1093         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1094                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1095         if (opts->gpg_sign_opt)
1096                 argv_array_push(&am.args, opts->gpg_sign_opt);
1097         status = run_command(&am);
1098         unlink(rebased_patches);
1099         free(rebased_patches);
1100
1101         if (!status) {
1102                 return move_to_original_branch(opts);
1103         }
1104
1105         if (is_directory(opts->state_dir))
1106                 rebase_write_basic_state(opts);
1107
1108         return status;
1109 }
1110
1111 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1112 {
1113         const char *argv[] = { NULL, NULL };
1114         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1115         int status;
1116         const char *backend, *backend_func;
1117
1118         if (opts->type == REBASE_INTERACTIVE) {
1119                 /* Run builtin interactive rebase */
1120                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1121                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1122                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1123                         opts->autosquash = 0;
1124                 }
1125                 if (opts->gpg_sign_opt) {
1126                         /* remove the leading "-S" */
1127                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1128                         free(opts->gpg_sign_opt);
1129                         opts->gpg_sign_opt = tmp;
1130                 }
1131
1132                 status = run_rebase_interactive(opts, action);
1133                 goto finished_rebase;
1134         }
1135
1136         if (opts->type == REBASE_AM) {
1137                 status = run_am(opts);
1138                 goto finished_rebase;
1139         }
1140
1141         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1142         add_var(&script_snippet, "state_dir", opts->state_dir);
1143
1144         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1145         add_var(&script_snippet, "upstream", opts->upstream ?
1146                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1147         add_var(&script_snippet, "head_name",
1148                 opts->head_name ? opts->head_name : "detached HEAD");
1149         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1150         add_var(&script_snippet, "onto", opts->onto ?
1151                 oid_to_hex(&opts->onto->object.oid) : NULL);
1152         add_var(&script_snippet, "onto_name", opts->onto_name);
1153         add_var(&script_snippet, "revisions", opts->revisions);
1154         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1155                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1156         add_var(&script_snippet, "GIT_QUIET",
1157                 opts->flags & REBASE_NO_QUIET ? "" : "t");
1158         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1159         add_var(&script_snippet, "git_am_opt", buf.buf);
1160         strbuf_release(&buf);
1161         add_var(&script_snippet, "verbose",
1162                 opts->flags & REBASE_VERBOSE ? "t" : "");
1163         add_var(&script_snippet, "diffstat",
1164                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1165         add_var(&script_snippet, "force_rebase",
1166                 opts->flags & REBASE_FORCE ? "t" : "");
1167         if (opts->switch_to)
1168                 add_var(&script_snippet, "switch_to", opts->switch_to);
1169         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1170         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1171         add_var(&script_snippet, "allow_rerere_autoupdate",
1172                 opts->allow_rerere_autoupdate ?
1173                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1174                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1175         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1176         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1177         add_var(&script_snippet, "cmd", opts->cmd);
1178         add_var(&script_snippet, "allow_empty_message",
1179                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1180         add_var(&script_snippet, "rebase_merges",
1181                 opts->rebase_merges ? "t" : "");
1182         add_var(&script_snippet, "rebase_cousins",
1183                 opts->rebase_cousins ? "t" : "");
1184         add_var(&script_snippet, "strategy", opts->strategy);
1185         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1186         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1187         add_var(&script_snippet, "squash_onto",
1188                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1189         add_var(&script_snippet, "git_format_patch_opt",
1190                 opts->git_format_patch_opt.buf);
1191
1192         if (is_interactive(opts) &&
1193             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1194                 strbuf_addstr(&script_snippet,
1195                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1196                 opts->autosquash = 0;
1197         }
1198
1199         switch (opts->type) {
1200         case REBASE_PRESERVE_MERGES:
1201                 backend = "git-rebase--preserve-merges";
1202                 backend_func = "git_rebase__preserve_merges";
1203                 break;
1204         default:
1205                 BUG("Unhandled rebase type %d", opts->type);
1206                 break;
1207         }
1208
1209         strbuf_addf(&script_snippet,
1210                     ". git-sh-setup && . %s && %s", backend, backend_func);
1211         argv[0] = script_snippet.buf;
1212
1213         status = run_command_v_opt(argv, RUN_USING_SHELL);
1214 finished_rebase:
1215         if (opts->dont_finish_rebase)
1216                 ; /* do nothing */
1217         else if (opts->type == REBASE_INTERACTIVE)
1218                 ; /* interactive rebase cleans up after itself */
1219         else if (status == 0) {
1220                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1221                         finish_rebase(opts);
1222         } else if (status == 2) {
1223                 struct strbuf dir = STRBUF_INIT;
1224
1225                 apply_autostash(opts);
1226                 strbuf_addstr(&dir, opts->state_dir);
1227                 remove_dir_recursively(&dir, 0);
1228                 strbuf_release(&dir);
1229                 die("Nothing to do");
1230         }
1231
1232         strbuf_release(&script_snippet);
1233
1234         return status ? -1 : 0;
1235 }
1236
1237 static int rebase_config(const char *var, const char *value, void *data)
1238 {
1239         struct rebase_options *opts = data;
1240
1241         if (!strcmp(var, "rebase.stat")) {
1242                 if (git_config_bool(var, value))
1243                         opts->flags |= REBASE_DIFFSTAT;
1244                 else
1245                         opts->flags &= ~REBASE_DIFFSTAT;
1246                 return 0;
1247         }
1248
1249         if (!strcmp(var, "rebase.autosquash")) {
1250                 opts->autosquash = git_config_bool(var, value);
1251                 return 0;
1252         }
1253
1254         if (!strcmp(var, "commit.gpgsign")) {
1255                 free(opts->gpg_sign_opt);
1256                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1257                         xstrdup("-S") : NULL;
1258                 return 0;
1259         }
1260
1261         if (!strcmp(var, "rebase.autostash")) {
1262                 opts->autostash = git_config_bool(var, value);
1263                 return 0;
1264         }
1265
1266         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1267                 opts->reschedule_failed_exec = git_config_bool(var, value);
1268                 return 0;
1269         }
1270
1271         if (!strcmp(var, "rebase.usebuiltin")) {
1272                 opts->use_legacy_rebase = !git_config_bool(var, value);
1273                 return 0;
1274         }
1275
1276         return git_default_config(var, value, data);
1277 }
1278
1279 /*
1280  * Determines whether the commits in from..to are linear, i.e. contain
1281  * no merge commits. This function *expects* `from` to be an ancestor of
1282  * `to`.
1283  */
1284 static int is_linear_history(struct commit *from, struct commit *to)
1285 {
1286         while (to && to != from) {
1287                 parse_commit(to);
1288                 if (!to->parents)
1289                         return 1;
1290                 if (to->parents->next)
1291                         return 0;
1292                 to = to->parents->item;
1293         }
1294         return 1;
1295 }
1296
1297 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1298                             struct commit *restrict_revision,
1299                             struct object_id *head_oid, struct object_id *merge_base)
1300 {
1301         struct commit *head = lookup_commit(the_repository, head_oid);
1302         struct commit_list *merge_bases = NULL;
1303         int res = 0;
1304
1305         if (!head)
1306                 goto done;
1307
1308         merge_bases = get_merge_bases(onto, head);
1309         if (!merge_bases || merge_bases->next) {
1310                 oidcpy(merge_base, &null_oid);
1311                 goto done;
1312         }
1313
1314         oidcpy(merge_base, &merge_bases->item->object.oid);
1315         if (!oideq(merge_base, &onto->object.oid))
1316                 goto done;
1317
1318         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1319                 goto done;
1320
1321         if (!upstream)
1322                 goto done;
1323
1324         free_commit_list(merge_bases);
1325         merge_bases = get_merge_bases(upstream, head);
1326         if (!merge_bases || merge_bases->next)
1327                 goto done;
1328
1329         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1330                 goto done;
1331
1332         res = 1;
1333
1334 done:
1335         free_commit_list(merge_bases);
1336         return res && is_linear_history(onto, head);
1337 }
1338
1339 /* -i followed by -m is still -i */
1340 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1341 {
1342         struct rebase_options *opts = opt->value;
1343
1344         BUG_ON_OPT_NEG(unset);
1345         BUG_ON_OPT_ARG(arg);
1346
1347         if (!is_interactive(opts))
1348                 opts->type = REBASE_MERGE;
1349
1350         return 0;
1351 }
1352
1353 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1354 static int parse_opt_interactive(const struct option *opt, const char *arg,
1355                                  int unset)
1356 {
1357         struct rebase_options *opts = opt->value;
1358
1359         BUG_ON_OPT_NEG(unset);
1360         BUG_ON_OPT_ARG(arg);
1361
1362         opts->type = REBASE_INTERACTIVE;
1363         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1364
1365         return 0;
1366 }
1367
1368 static enum empty_type parse_empty_value(const char *value)
1369 {
1370         if (!strcasecmp(value, "drop"))
1371                 return EMPTY_DROP;
1372         else if (!strcasecmp(value, "keep"))
1373                 return EMPTY_KEEP;
1374         else if (!strcasecmp(value, "ask"))
1375                 return EMPTY_ASK;
1376
1377         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
1378 }
1379
1380 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
1381 {
1382         struct rebase_options *options = opt->value;
1383         enum empty_type value = parse_empty_value(arg);
1384
1385         BUG_ON_OPT_NEG(unset);
1386
1387         options->empty = value;
1388         return 0;
1389 }
1390
1391 static void NORETURN error_on_missing_default_upstream(void)
1392 {
1393         struct branch *current_branch = branch_get(NULL);
1394
1395         printf(_("%s\n"
1396                  "Please specify which branch you want to rebase against.\n"
1397                  "See git-rebase(1) for details.\n"
1398                  "\n"
1399                  "    git rebase '<branch>'\n"
1400                  "\n"),
1401                 current_branch ? _("There is no tracking information for "
1402                         "the current branch.") :
1403                         _("You are not currently on a branch."));
1404
1405         if (current_branch) {
1406                 const char *remote = current_branch->remote_name;
1407
1408                 if (!remote)
1409                         remote = _("<remote>");
1410
1411                 printf(_("If you wish to set tracking information for this "
1412                          "branch you can do so with:\n"
1413                          "\n"
1414                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1415                          "\n"),
1416                        remote, current_branch->name);
1417         }
1418         exit(1);
1419 }
1420
1421 static void set_reflog_action(struct rebase_options *options)
1422 {
1423         const char *env;
1424         struct strbuf buf = STRBUF_INIT;
1425
1426         if (!is_interactive(options))
1427                 return;
1428
1429         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1430         if (env && strcmp("rebase", env))
1431                 return; /* only override it if it is "rebase" */
1432
1433         strbuf_addf(&buf, "rebase -i (%s)", options->action);
1434         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1435         strbuf_release(&buf);
1436 }
1437
1438 static int check_exec_cmd(const char *cmd)
1439 {
1440         if (strchr(cmd, '\n'))
1441                 return error(_("exec commands cannot contain newlines"));
1442
1443         /* Does the command consist purely of whitespace? */
1444         if (!cmd[strspn(cmd, " \t\r\f\v")])
1445                 return error(_("empty exec command"));
1446
1447         return 0;
1448 }
1449
1450
1451 int cmd_rebase(int argc, const char **argv, const char *prefix)
1452 {
1453         struct rebase_options options = REBASE_OPTIONS_INIT;
1454         const char *branch_name;
1455         int ret, flags, total_argc, in_progress = 0;
1456         int keep_base = 0;
1457         int ok_to_skip_pre_rebase = 0;
1458         struct strbuf msg = STRBUF_INIT;
1459         struct strbuf revisions = STRBUF_INIT;
1460         struct strbuf buf = STRBUF_INIT;
1461         struct object_id merge_base;
1462         enum action action = ACTION_NONE;
1463         const char *gpg_sign = NULL;
1464         struct string_list exec = STRING_LIST_INIT_NODUP;
1465         const char *rebase_merges = NULL;
1466         int fork_point = -1;
1467         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1468         struct object_id squash_onto;
1469         char *squash_onto_name = NULL;
1470         int reschedule_failed_exec = -1;
1471         struct option builtin_rebase_options[] = {
1472                 OPT_STRING(0, "onto", &options.onto_name,
1473                            N_("revision"),
1474                            N_("rebase onto given branch instead of upstream")),
1475                 OPT_BOOL(0, "keep-base", &keep_base,
1476                          N_("use the merge-base of upstream and branch as the current base")),
1477                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1478                          N_("allow pre-rebase hook to run")),
1479                 OPT_NEGBIT('q', "quiet", &options.flags,
1480                            N_("be quiet. implies --no-stat"),
1481                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1482                 OPT_BIT('v', "verbose", &options.flags,
1483                         N_("display a diffstat of what changed upstream"),
1484                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1485                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1486                         N_("do not show diffstat of what changed upstream"),
1487                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1488                 OPT_BOOL(0, "signoff", &options.signoff,
1489                          N_("add a Signed-off-by: line to each commit")),
1490                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1491                                   NULL, N_("passed to 'git am'"),
1492                                   PARSE_OPT_NOARG),
1493                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1494                                   &options.git_am_opts, NULL,
1495                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1496                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1497                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1498                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1499                                   N_("passed to 'git apply'"), 0),
1500                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1501                                   N_("action"), N_("passed to 'git apply'"), 0),
1502                 OPT_BIT('f', "force-rebase", &options.flags,
1503                         N_("cherry-pick all commits, even if unchanged"),
1504                         REBASE_FORCE),
1505                 OPT_BIT(0, "no-ff", &options.flags,
1506                         N_("cherry-pick all commits, even if unchanged"),
1507                         REBASE_FORCE),
1508                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1509                             ACTION_CONTINUE),
1510                 OPT_CMDMODE(0, "skip", &action,
1511                             N_("skip current patch and continue"), ACTION_SKIP),
1512                 OPT_CMDMODE(0, "abort", &action,
1513                             N_("abort and check out the original branch"),
1514                             ACTION_ABORT),
1515                 OPT_CMDMODE(0, "quit", &action,
1516                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1517                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1518                             "during an interactive rebase"), ACTION_EDIT_TODO),
1519                 OPT_CMDMODE(0, "show-current-patch", &action,
1520                             N_("show the patch file being applied or merged"),
1521                             ACTION_SHOW_CURRENT_PATCH),
1522                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1523                         N_("use merging strategies to rebase"),
1524                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1525                         parse_opt_merge },
1526                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1527                         N_("let the user edit the list of commits to rebase"),
1528                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1529                         parse_opt_interactive },
1530                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1531                               N_("(DEPRECATED) try to recreate merges instead of "
1532                                  "ignoring them"),
1533                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1534                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1535                 OPT_CALLBACK_F(0, "empty", &options, N_("{drop,keep,ask}"),
1536                                N_("how to handle commits that become empty"),
1537                                PARSE_OPT_NONEG, parse_opt_empty),
1538                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
1539                         N_("(DEPRECATED) keep empty commits"),
1540                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1541                         parse_opt_keep_empty },
1542                 OPT_BOOL(0, "autosquash", &options.autosquash,
1543                          N_("move commits that begin with "
1544                             "squash!/fixup! under -i")),
1545                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1546                         N_("GPG-sign commits"),
1547                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1548                 OPT_BOOL(0, "autostash", &options.autostash,
1549                          N_("automatically stash/stash pop before and after")),
1550                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1551                                 N_("add exec lines after each commit of the "
1552                                    "editable list")),
1553                 OPT_BOOL_F(0, "allow-empty-message",
1554                            &options.allow_empty_message,
1555                            N_("allow rebasing commits with empty messages"),
1556                            PARSE_OPT_HIDDEN),
1557                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1558                         N_("mode"),
1559                         N_("try to rebase merges instead of skipping them"),
1560                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1561                 OPT_BOOL(0, "fork-point", &fork_point,
1562                          N_("use 'merge-base --fork-point' to refine upstream")),
1563                 OPT_STRING('s', "strategy", &options.strategy,
1564                            N_("strategy"), N_("use the given merge strategy")),
1565                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1566                                 N_("option"),
1567                                 N_("pass the argument through to the merge "
1568                                    "strategy")),
1569                 OPT_BOOL(0, "root", &options.root,
1570                          N_("rebase all reachable commits up to the root(s)")),
1571                 OPT_BOOL(0, "reschedule-failed-exec",
1572                          &reschedule_failed_exec,
1573                          N_("automatically re-schedule any `exec` that fails")),
1574                 OPT_END(),
1575         };
1576         int i;
1577
1578         if (argc == 2 && !strcmp(argv[1], "-h"))
1579                 usage_with_options(builtin_rebase_usage,
1580                                    builtin_rebase_options);
1581
1582         options.allow_empty_message = 1;
1583         git_config(rebase_config, &options);
1584
1585         if (options.use_legacy_rebase ||
1586             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1587                 warning(_("the rebase.useBuiltin support has been removed!\n"
1588                           "See its entry in 'git help config' for details."));
1589
1590         strbuf_reset(&buf);
1591         strbuf_addf(&buf, "%s/applying", apply_dir());
1592         if(file_exists(buf.buf))
1593                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1594
1595         if (is_directory(apply_dir())) {
1596                 options.type = REBASE_AM;
1597                 options.state_dir = apply_dir();
1598         } else if (is_directory(merge_dir())) {
1599                 strbuf_reset(&buf);
1600                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1601                 if (is_directory(buf.buf)) {
1602                         options.type = REBASE_PRESERVE_MERGES;
1603                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1604                 } else {
1605                         strbuf_reset(&buf);
1606                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1607                         if(file_exists(buf.buf)) {
1608                                 options.type = REBASE_INTERACTIVE;
1609                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1610                         } else
1611                                 options.type = REBASE_MERGE;
1612                 }
1613                 options.state_dir = merge_dir();
1614         }
1615
1616         if (options.type != REBASE_UNSPECIFIED)
1617                 in_progress = 1;
1618
1619         total_argc = argc;
1620         argc = parse_options(argc, argv, prefix,
1621                              builtin_rebase_options,
1622                              builtin_rebase_usage, 0);
1623
1624         if (action != ACTION_NONE && total_argc != 2) {
1625                 usage_with_options(builtin_rebase_usage,
1626                                    builtin_rebase_options);
1627         }
1628
1629         if (argc > 2)
1630                 usage_with_options(builtin_rebase_usage,
1631                                    builtin_rebase_options);
1632
1633         if (options.type == REBASE_PRESERVE_MERGES)
1634                 warning(_("git rebase --preserve-merges is deprecated. "
1635                           "Use --rebase-merges instead."));
1636
1637         if (keep_base) {
1638                 if (options.onto_name)
1639                         die(_("cannot combine '--keep-base' with '--onto'"));
1640                 if (options.root)
1641                         die(_("cannot combine '--keep-base' with '--root'"));
1642         }
1643
1644         if (action != ACTION_NONE && !in_progress)
1645                 die(_("No rebase in progress?"));
1646         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1647
1648         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1649                 die(_("The --edit-todo action can only be used during "
1650                       "interactive rebase."));
1651
1652         if (trace2_is_enabled()) {
1653                 if (is_interactive(&options))
1654                         trace2_cmd_mode("interactive");
1655                 else if (exec.nr)
1656                         trace2_cmd_mode("interactive-exec");
1657                 else
1658                         trace2_cmd_mode(action_names[action]);
1659         }
1660
1661         switch (action) {
1662         case ACTION_CONTINUE: {
1663                 struct object_id head;
1664                 struct lock_file lock_file = LOCK_INIT;
1665                 int fd;
1666
1667                 options.action = "continue";
1668                 set_reflog_action(&options);
1669
1670                 /* Sanity check */
1671                 if (get_oid("HEAD", &head))
1672                         die(_("Cannot read HEAD"));
1673
1674                 fd = hold_locked_index(&lock_file, 0);
1675                 if (repo_read_index(the_repository) < 0)
1676                         die(_("could not read index"));
1677                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1678                               NULL);
1679                 if (0 <= fd)
1680                         repo_update_index_if_able(the_repository, &lock_file);
1681                 rollback_lock_file(&lock_file);
1682
1683                 if (has_unstaged_changes(the_repository, 1)) {
1684                         puts(_("You must edit all merge conflicts and then\n"
1685                                "mark them as resolved using git add"));
1686                         exit(1);
1687                 }
1688                 if (read_basic_state(&options))
1689                         exit(1);
1690                 goto run_rebase;
1691         }
1692         case ACTION_SKIP: {
1693                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1694
1695                 options.action = "skip";
1696                 set_reflog_action(&options);
1697
1698                 rerere_clear(the_repository, &merge_rr);
1699                 string_list_clear(&merge_rr, 1);
1700
1701                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1702                                NULL, NULL) < 0)
1703                         die(_("could not discard worktree changes"));
1704                 remove_branch_state(the_repository, 0);
1705                 if (read_basic_state(&options))
1706                         exit(1);
1707                 goto run_rebase;
1708         }
1709         case ACTION_ABORT: {
1710                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1711                 options.action = "abort";
1712                 set_reflog_action(&options);
1713
1714                 rerere_clear(the_repository, &merge_rr);
1715                 string_list_clear(&merge_rr, 1);
1716
1717                 if (read_basic_state(&options))
1718                         exit(1);
1719                 if (reset_head(&options.orig_head, "reset",
1720                                options.head_name, RESET_HEAD_HARD,
1721                                NULL, NULL) < 0)
1722                         die(_("could not move back to %s"),
1723                             oid_to_hex(&options.orig_head));
1724                 remove_branch_state(the_repository, 0);
1725                 ret = !!finish_rebase(&options);
1726                 goto cleanup;
1727         }
1728         case ACTION_QUIT: {
1729                 if (options.type == REBASE_INTERACTIVE) {
1730                         struct replay_opts replay = REPLAY_OPTS_INIT;
1731
1732                         replay.action = REPLAY_INTERACTIVE_REBASE;
1733                         ret = !!sequencer_remove_state(&replay);
1734                 } else {
1735                         strbuf_reset(&buf);
1736                         strbuf_addstr(&buf, options.state_dir);
1737                         ret = !!remove_dir_recursively(&buf, 0);
1738                         if (ret)
1739                                 error(_("could not remove '%s'"),
1740                                        options.state_dir);
1741                 }
1742                 goto cleanup;
1743         }
1744         case ACTION_EDIT_TODO:
1745                 options.action = "edit-todo";
1746                 options.dont_finish_rebase = 1;
1747                 goto run_rebase;
1748         case ACTION_SHOW_CURRENT_PATCH:
1749                 options.action = "show-current-patch";
1750                 options.dont_finish_rebase = 1;
1751                 goto run_rebase;
1752         case ACTION_NONE:
1753                 break;
1754         default:
1755                 BUG("action: %d", action);
1756         }
1757
1758         /* Make sure no rebase is in progress */
1759         if (in_progress) {
1760                 const char *last_slash = strrchr(options.state_dir, '/');
1761                 const char *state_dir_base =
1762                         last_slash ? last_slash + 1 : options.state_dir;
1763                 const char *cmd_live_rebase =
1764                         "git rebase (--continue | --abort | --skip)";
1765                 strbuf_reset(&buf);
1766                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1767                 die(_("It seems that there is already a %s directory, and\n"
1768                       "I wonder if you are in the middle of another rebase.  "
1769                       "If that is the\n"
1770                       "case, please try\n\t%s\n"
1771                       "If that is not the case, please\n\t%s\n"
1772                       "and run me again.  I am stopping in case you still "
1773                       "have something\n"
1774                       "valuable there.\n"),
1775                     state_dir_base, cmd_live_rebase, buf.buf);
1776         }
1777
1778         for (i = 0; i < options.git_am_opts.argc; i++) {
1779                 const char *option = options.git_am_opts.argv[i], *p;
1780                 if (!strcmp(option, "--committer-date-is-author-date") ||
1781                     !strcmp(option, "--ignore-date") ||
1782                     !strcmp(option, "--whitespace=fix") ||
1783                     !strcmp(option, "--whitespace=strip"))
1784                         options.flags |= REBASE_FORCE;
1785                 else if (skip_prefix(option, "-C", &p)) {
1786                         while (*p)
1787                                 if (!isdigit(*(p++)))
1788                                         die(_("switch `C' expects a "
1789                                               "numerical value"));
1790                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1791                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1792                             strcmp(p, "error") && strcmp(p, "error-all"))
1793                                 die("Invalid whitespace option: '%s'", p);
1794                 }
1795         }
1796
1797         for (i = 0; i < exec.nr; i++)
1798                 if (check_exec_cmd(exec.items[i].string))
1799                         exit(1);
1800
1801         if (!(options.flags & REBASE_NO_QUIET))
1802                 argv_array_push(&options.git_am_opts, "-q");
1803
1804         if (options.empty != EMPTY_UNSPECIFIED)
1805                 imply_interactive(&options, "--empty");
1806
1807         if (gpg_sign) {
1808                 free(options.gpg_sign_opt);
1809                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1810         }
1811
1812         if (exec.nr) {
1813                 int i;
1814
1815                 imply_interactive(&options, "--exec");
1816
1817                 strbuf_reset(&buf);
1818                 for (i = 0; i < exec.nr; i++)
1819                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1820                 options.cmd = xstrdup(buf.buf);
1821         }
1822
1823         if (rebase_merges) {
1824                 if (!*rebase_merges)
1825                         ; /* default mode; do nothing */
1826                 else if (!strcmp("rebase-cousins", rebase_merges))
1827                         options.rebase_cousins = 1;
1828                 else if (strcmp("no-rebase-cousins", rebase_merges))
1829                         die(_("Unknown mode: %s"), rebase_merges);
1830                 options.rebase_merges = 1;
1831                 imply_interactive(&options, "--rebase-merges");
1832         }
1833
1834         if (strategy_options.nr) {
1835                 int i;
1836
1837                 if (!options.strategy)
1838                         options.strategy = "recursive";
1839
1840                 strbuf_reset(&buf);
1841                 for (i = 0; i < strategy_options.nr; i++)
1842                         strbuf_addf(&buf, " --%s",
1843                                     strategy_options.items[i].string);
1844                 options.strategy_opts = xstrdup(buf.buf);
1845         }
1846
1847         if (options.strategy) {
1848                 options.strategy = xstrdup(options.strategy);
1849                 switch (options.type) {
1850                 case REBASE_AM:
1851                         die(_("--strategy requires --merge or --interactive"));
1852                 case REBASE_MERGE:
1853                 case REBASE_INTERACTIVE:
1854                 case REBASE_PRESERVE_MERGES:
1855                         /* compatible */
1856                         break;
1857                 case REBASE_UNSPECIFIED:
1858                         options.type = REBASE_MERGE;
1859                         break;
1860                 default:
1861                         BUG("unhandled rebase type (%d)", options.type);
1862                 }
1863         }
1864
1865         if (options.type == REBASE_MERGE)
1866                 imply_interactive(&options, "--merge");
1867
1868         if (options.root && !options.onto_name)
1869                 imply_interactive(&options, "--root without --onto");
1870
1871         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1872                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1873
1874         switch (options.type) {
1875         case REBASE_MERGE:
1876         case REBASE_INTERACTIVE:
1877         case REBASE_PRESERVE_MERGES:
1878                 options.state_dir = merge_dir();
1879                 break;
1880         case REBASE_AM:
1881                 options.state_dir = apply_dir();
1882                 break;
1883         default:
1884                 /* the default rebase backend is `--am` */
1885                 options.type = REBASE_AM;
1886                 options.state_dir = apply_dir();
1887                 break;
1888         }
1889
1890         if (options.empty == EMPTY_UNSPECIFIED) {
1891                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1892                         options.empty = EMPTY_ASK;
1893                 else if (exec.nr > 0)
1894                         options.empty = EMPTY_KEEP;
1895                 else
1896                         options.empty = EMPTY_DROP;
1897         }
1898         if (reschedule_failed_exec > 0 && !is_interactive(&options))
1899                 die(_("--reschedule-failed-exec requires "
1900                       "--exec or --interactive"));
1901         if (reschedule_failed_exec >= 0)
1902                 options.reschedule_failed_exec = reschedule_failed_exec;
1903
1904         if (options.git_am_opts.argc) {
1905                 /* all am options except -q are compatible only with --am */
1906                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1907                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1908                                 break;
1909
1910                 if (is_interactive(&options) && i >= 0)
1911                         die(_("cannot combine am options with either "
1912                               "interactive or merge options"));
1913         }
1914
1915         if (options.signoff) {
1916                 if (options.type == REBASE_PRESERVE_MERGES)
1917                         die("cannot combine '--signoff' with "
1918                             "'--preserve-merges'");
1919                 argv_array_push(&options.git_am_opts, "--signoff");
1920                 options.flags |= REBASE_FORCE;
1921         }
1922
1923         if (options.type == REBASE_PRESERVE_MERGES) {
1924                 /*
1925                  * Note: incompatibility with --signoff handled in signoff block above
1926                  * Note: incompatibility with --interactive is just a strong warning;
1927                  *       git-rebase.txt caveats with "unless you know what you are doing"
1928                  */
1929                 if (options.rebase_merges)
1930                         die(_("cannot combine '--preserve-merges' with "
1931                               "'--rebase-merges'"));
1932
1933                 if (options.reschedule_failed_exec)
1934                         die(_("error: cannot combine '--preserve-merges' with "
1935                               "'--reschedule-failed-exec'"));
1936         }
1937
1938         if (!options.root) {
1939                 if (argc < 1) {
1940                         struct branch *branch;
1941
1942                         branch = branch_get(NULL);
1943                         options.upstream_name = branch_get_upstream(branch,
1944                                                                     NULL);
1945                         if (!options.upstream_name)
1946                                 error_on_missing_default_upstream();
1947                         if (fork_point < 0)
1948                                 fork_point = 1;
1949                 } else {
1950                         options.upstream_name = argv[0];
1951                         argc--;
1952                         argv++;
1953                         if (!strcmp(options.upstream_name, "-"))
1954                                 options.upstream_name = "@{-1}";
1955                 }
1956                 options.upstream = peel_committish(options.upstream_name);
1957                 if (!options.upstream)
1958                         die(_("invalid upstream '%s'"), options.upstream_name);
1959                 options.upstream_arg = options.upstream_name;
1960         } else {
1961                 if (!options.onto_name) {
1962                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1963                                         &squash_onto, NULL, NULL) < 0)
1964                                 die(_("Could not create new root commit"));
1965                         options.squash_onto = &squash_onto;
1966                         options.onto_name = squash_onto_name =
1967                                 xstrdup(oid_to_hex(&squash_onto));
1968                 } else
1969                         options.root_with_onto = 1;
1970
1971                 options.upstream_name = NULL;
1972                 options.upstream = NULL;
1973                 if (argc > 1)
1974                         usage_with_options(builtin_rebase_usage,
1975                                            builtin_rebase_options);
1976                 options.upstream_arg = "--root";
1977         }
1978
1979         /* Make sure the branch to rebase onto is valid. */
1980         if (keep_base) {
1981                 strbuf_reset(&buf);
1982                 strbuf_addstr(&buf, options.upstream_name);
1983                 strbuf_addstr(&buf, "...");
1984                 options.onto_name = xstrdup(buf.buf);
1985         } else if (!options.onto_name)
1986                 options.onto_name = options.upstream_name;
1987         if (strstr(options.onto_name, "...")) {
1988                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
1989                         if (keep_base)
1990                                 die(_("'%s': need exactly one merge base with branch"),
1991                                     options.upstream_name);
1992                         else
1993                                 die(_("'%s': need exactly one merge base"),
1994                                     options.onto_name);
1995                 }
1996                 options.onto = lookup_commit_or_die(&merge_base,
1997                                                     options.onto_name);
1998         } else {
1999                 options.onto = peel_committish(options.onto_name);
2000                 if (!options.onto)
2001                         die(_("Does not point to a valid commit '%s'"),
2002                                 options.onto_name);
2003         }
2004
2005         /*
2006          * If the branch to rebase is given, that is the branch we will rebase
2007          * branch_name -- branch/commit being rebased, or
2008          *                HEAD (already detached)
2009          * orig_head -- commit object name of tip of the branch before rebasing
2010          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
2011          */
2012         if (argc == 1) {
2013                 /* Is it "rebase other branchname" or "rebase other commit"? */
2014                 branch_name = argv[0];
2015                 options.switch_to = argv[0];
2016
2017                 /* Is it a local branch? */
2018                 strbuf_reset(&buf);
2019                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
2020                 if (!read_ref(buf.buf, &options.orig_head))
2021                         options.head_name = xstrdup(buf.buf);
2022                 /* If not is it a valid ref (branch or commit)? */
2023                 else if (!get_oid(branch_name, &options.orig_head))
2024                         options.head_name = NULL;
2025                 else
2026                         die(_("fatal: no such branch/commit '%s'"),
2027                             branch_name);
2028         } else if (argc == 0) {
2029                 /* Do not need to switch branches, we are already on it. */
2030                 options.head_name =
2031                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
2032                                          &flags));
2033                 if (!options.head_name)
2034                         die(_("No such ref: %s"), "HEAD");
2035                 if (flags & REF_ISSYMREF) {
2036                         if (!skip_prefix(options.head_name,
2037                                          "refs/heads/", &branch_name))
2038                                 branch_name = options.head_name;
2039
2040                 } else {
2041                         FREE_AND_NULL(options.head_name);
2042                         branch_name = "HEAD";
2043                 }
2044                 if (get_oid("HEAD", &options.orig_head))
2045                         die(_("Could not resolve HEAD to a revision"));
2046         } else
2047                 BUG("unexpected number of arguments left to parse");
2048
2049         if (fork_point > 0) {
2050                 struct commit *head =
2051                         lookup_commit_reference(the_repository,
2052                                                 &options.orig_head);
2053                 options.restrict_revision =
2054                         get_fork_point(options.upstream_name, head);
2055         }
2056
2057         if (repo_read_index(the_repository) < 0)
2058                 die(_("could not read index"));
2059
2060         if (options.autostash) {
2061                 struct lock_file lock_file = LOCK_INIT;
2062                 int fd;
2063
2064                 fd = hold_locked_index(&lock_file, 0);
2065                 refresh_cache(REFRESH_QUIET);
2066                 if (0 <= fd)
2067                         repo_update_index_if_able(the_repository, &lock_file);
2068                 rollback_lock_file(&lock_file);
2069
2070                 if (has_unstaged_changes(the_repository, 1) ||
2071                     has_uncommitted_changes(the_repository, 1)) {
2072                         const char *autostash =
2073                                 state_dir_path("autostash", &options);
2074                         struct child_process stash = CHILD_PROCESS_INIT;
2075                         struct object_id oid;
2076
2077                         argv_array_pushl(&stash.args,
2078                                          "stash", "create", "autostash", NULL);
2079                         stash.git_cmd = 1;
2080                         stash.no_stdin = 1;
2081                         strbuf_reset(&buf);
2082                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
2083                                 die(_("Cannot autostash"));
2084                         strbuf_trim_trailing_newline(&buf);
2085                         if (get_oid(buf.buf, &oid))
2086                                 die(_("Unexpected stash response: '%s'"),
2087                                     buf.buf);
2088                         strbuf_reset(&buf);
2089                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
2090
2091                         if (safe_create_leading_directories_const(autostash))
2092                                 die(_("Could not create directory for '%s'"),
2093                                     options.state_dir);
2094                         write_file(autostash, "%s", oid_to_hex(&oid));
2095                         printf(_("Created autostash: %s\n"), buf.buf);
2096                         if (reset_head(NULL, "reset --hard",
2097                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2098                                 die(_("could not reset --hard"));
2099
2100                         if (discard_index(the_repository->index) < 0 ||
2101                                 repo_read_index(the_repository) < 0)
2102                                 die(_("could not read index"));
2103                 }
2104         }
2105
2106         if (require_clean_work_tree(the_repository, "rebase",
2107                                     _("Please commit or stash them."), 1, 1)) {
2108                 ret = 1;
2109                 goto cleanup;
2110         }
2111
2112         /*
2113          * Now we are rebasing commits upstream..orig_head (or with --root,
2114          * everything leading up to orig_head) on top of onto.
2115          */
2116
2117         /*
2118          * Check if we are already based on onto with linear history,
2119          * in which case we could fast-forward without replacing the commits
2120          * with new commits recreated by replaying their changes. This
2121          * optimization must not be done if this is an interactive rebase.
2122          */
2123         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
2124                     &options.orig_head, &merge_base) &&
2125             !is_interactive(&options)) {
2126                 int flag;
2127
2128                 if (!(options.flags & REBASE_FORCE)) {
2129                         /* Lazily switch to the target branch if needed... */
2130                         if (options.switch_to) {
2131                                 struct object_id oid;
2132
2133                                 if (get_oid(options.switch_to, &oid) < 0) {
2134                                         ret = !!error(_("could not parse '%s'"),
2135                                                       options.switch_to);
2136                                         goto cleanup;
2137                                 }
2138
2139                                 strbuf_reset(&buf);
2140                                 strbuf_addf(&buf, "%s: checkout %s",
2141                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2142                                             options.switch_to);
2143                                 if (reset_head(&oid, "checkout",
2144                                                options.head_name,
2145                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2146                                                NULL, buf.buf) < 0) {
2147                                         ret = !!error(_("could not switch to "
2148                                                         "%s"),
2149                                                       options.switch_to);
2150                                         goto cleanup;
2151                                 }
2152                         }
2153
2154                         if (!(options.flags & REBASE_NO_QUIET))
2155                                 ; /* be quiet */
2156                         else if (!strcmp(branch_name, "HEAD") &&
2157                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2158                                 puts(_("HEAD is up to date."));
2159                         else
2160                                 printf(_("Current branch %s is up to date.\n"),
2161                                        branch_name);
2162                         ret = !!finish_rebase(&options);
2163                         goto cleanup;
2164                 } else if (!(options.flags & REBASE_NO_QUIET))
2165                         ; /* be quiet */
2166                 else if (!strcmp(branch_name, "HEAD") &&
2167                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2168                         puts(_("HEAD is up to date, rebase forced."));
2169                 else
2170                         printf(_("Current branch %s is up to date, rebase "
2171                                  "forced.\n"), branch_name);
2172         }
2173
2174         /* If a hook exists, give it a chance to interrupt*/
2175         if (!ok_to_skip_pre_rebase &&
2176             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2177                         argc ? argv[0] : NULL, NULL))
2178                 die(_("The pre-rebase hook refused to rebase."));
2179
2180         if (options.flags & REBASE_DIFFSTAT) {
2181                 struct diff_options opts;
2182
2183                 if (options.flags & REBASE_VERBOSE) {
2184                         if (is_null_oid(&merge_base))
2185                                 printf(_("Changes to %s:\n"),
2186                                        oid_to_hex(&options.onto->object.oid));
2187                         else
2188                                 printf(_("Changes from %s to %s:\n"),
2189                                        oid_to_hex(&merge_base),
2190                                        oid_to_hex(&options.onto->object.oid));
2191                 }
2192
2193                 /* We want color (if set), but no pager */
2194                 diff_setup(&opts);
2195                 opts.stat_width = -1; /* use full terminal width */
2196                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2197                 opts.output_format |=
2198                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2199                 opts.detect_rename = DIFF_DETECT_RENAME;
2200                 diff_setup_done(&opts);
2201                 diff_tree_oid(is_null_oid(&merge_base) ?
2202                               the_hash_algo->empty_tree : &merge_base,
2203                               &options.onto->object.oid, "", &opts);
2204                 diffcore_std(&opts);
2205                 diff_flush(&opts);
2206         }
2207
2208         if (is_interactive(&options))
2209                 goto run_rebase;
2210
2211         /* Detach HEAD and reset the tree */
2212         if (options.flags & REBASE_NO_QUIET)
2213                 printf(_("First, rewinding head to replay your work on top of "
2214                          "it...\n"));
2215
2216         strbuf_addf(&msg, "%s: checkout %s",
2217                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2218         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2219                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2220                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2221                        NULL, msg.buf))
2222                 die(_("Could not detach HEAD"));
2223         strbuf_release(&msg);
2224
2225         /*
2226          * If the onto is a proper descendant of the tip of the branch, then
2227          * we just fast-forwarded.
2228          */
2229         strbuf_reset(&msg);
2230         if (oideq(&merge_base, &options.orig_head)) {
2231                 printf(_("Fast-forwarded %s to %s.\n"),
2232                         branch_name, options.onto_name);
2233                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2234                         options.head_name ? options.head_name : "detached HEAD",
2235                         oid_to_hex(&options.onto->object.oid));
2236                 reset_head(NULL, "Fast-forwarded", options.head_name,
2237                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2238                 strbuf_release(&msg);
2239                 ret = !!finish_rebase(&options);
2240                 goto cleanup;
2241         }
2242
2243         strbuf_addf(&revisions, "%s..%s",
2244                     options.root ? oid_to_hex(&options.onto->object.oid) :
2245                     (options.restrict_revision ?
2246                      oid_to_hex(&options.restrict_revision->object.oid) :
2247                      oid_to_hex(&options.upstream->object.oid)),
2248                     oid_to_hex(&options.orig_head));
2249
2250         options.revisions = revisions.buf;
2251
2252 run_rebase:
2253         ret = !!run_specific_rebase(&options, action);
2254
2255 cleanup:
2256         strbuf_release(&buf);
2257         strbuf_release(&revisions);
2258         free(options.head_name);
2259         free(options.gpg_sign_opt);
2260         free(options.cmd);
2261         free(squash_onto_name);
2262         return ret;
2263 }