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_APPLY,
  48         REBASE_MERGE,
  49         REBASE_PRESERVE_MERGES
  50 };
  51
  52 enum empty_type {
  53         EMPTY_UNSPECIFIED = -1,
  54         EMPTY_DROP,
  55         EMPTY_KEEP,
  56         EMPTY_ASK
  57 };
  58
  59 struct rebase_options {
  60         enum rebase_type type;
  61         enum empty_type empty;
  62         const char *default_backend;
  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         int committer_date_is_author_date;
  92         int ignore_date;
  93         char *cmd;
  94         int allow_empty_message;
  95         int rebase_merges, rebase_cousins;
  96         char *strategy, *strategy_opts;
  97         struct strbuf git_format_patch_opt;
  98         int reschedule_failed_exec;
  99         int use_legacy_rebase;
 100 };
 101
 102 #define REBASE_OPTIONS_INIT {                           \
 103                 .type = REBASE_UNSPECIFIED,             \
 104                 .empty = EMPTY_UNSPECIFIED,             \
 105                 .default_backend = "merge",             \
 106                 .flags = REBASE_NO_QUIET,               \
 107                 .git_am_opts = ARGV_ARRAY_INIT,         \
 108                 .git_format_patch_opt = STRBUF_INIT     \
 109         }
 110
 111 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 112 {
 113         struct replay_opts replay = REPLAY_OPTS_INIT;
 114
 115         replay.action = REPLAY_INTERACTIVE_REBASE;
 116         sequencer_init_config(&replay);
 117
 118         replay.signoff = opts->signoff;
 119         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 120         if (opts->allow_rerere_autoupdate)
 121                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 122         replay.allow_empty = 1;
 123         replay.allow_empty_message = opts->allow_empty_message;
 124         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
 125         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
 126         replay.quiet = !(opts->flags & REBASE_NO_QUIET);
 127         replay.verbose = opts->flags & REBASE_VERBOSE;
 128         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 129         replay.committer_date_is_author_date =
 130                                         opts->committer_date_is_author_date;
 131         replay.ignore_date = opts->ignore_date;
 132         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 133         replay.strategy = opts->strategy;
 134
 135         if (opts->strategy_opts)
 136                 parse_strategy_opts(&replay, opts->strategy_opts);
 137
 138         if (opts->squash_onto) {
 139                 oidcpy(&replay.squash_onto, opts->squash_onto);
 140                 replay.have_squash_onto = 1;
 141         }
 142
 143         return replay;
 144 }
 145
 146 enum action {
 147         ACTION_NONE = 0,
 148         ACTION_CONTINUE,
 149         ACTION_SKIP,
 150         ACTION_ABORT,
 151         ACTION_QUIT,
 152         ACTION_EDIT_TODO,
 153         ACTION_SHOW_CURRENT_PATCH,
 154         ACTION_SHORTEN_OIDS,
 155         ACTION_EXPAND_OIDS,
 156         ACTION_CHECK_TODO_LIST,
 157         ACTION_REARRANGE_SQUASH,
 158         ACTION_ADD_EXEC
 159 };
 160
 161 static const char *action_names[] = { "undefined",
 162                                       "continue",
 163                                       "skip",
 164                                       "abort",
 165                                       "quit",
 166                                       "edit_todo",
 167                                       "show_current_patch" };
 168
 169 static int add_exec_commands(struct string_list *commands)
 170 {
 171         const char *todo_file = rebase_path_todo();
 172         struct todo_list todo_list = TODO_LIST_INIT;
 173         int res;
 174
 175         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 176                 return error_errno(_("could not read '%s'."), todo_file);
 177
 178         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 179                                         &todo_list)) {
 180                 todo_list_release(&todo_list);
 181                 return error(_("unusable todo list: '%s'"), todo_file);
 182         }
 183
 184         todo_list_add_exec_commands(&todo_list, commands);
 185         res = todo_list_write_to_file(the_repository, &todo_list,
 186                                       todo_file, NULL, NULL, -1, 0);
 187         todo_list_release(&todo_list);
 188
 189         if (res)
 190                 return error_errno(_("could not write '%s'."), todo_file);
 191         return 0;
 192 }
 193
 194 static int rearrange_squash_in_todo_file(void)
 195 {
 196         const char *todo_file = rebase_path_todo();
 197         struct todo_list todo_list = TODO_LIST_INIT;
 198         int res = 0;
 199
 200         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 201                 return error_errno(_("could not read '%s'."), todo_file);
 202         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 203                                         &todo_list)) {
 204                 todo_list_release(&todo_list);
 205                 return error(_("unusable todo list: '%s'"), todo_file);
 206         }
 207
 208         res = todo_list_rearrange_squash(&todo_list);
 209         if (!res)
 210                 res = todo_list_write_to_file(the_repository, &todo_list,
 211                                               todo_file, NULL, NULL, -1, 0);
 212
 213         todo_list_release(&todo_list);
 214
 215         if (res)
 216                 return error_errno(_("could not write '%s'."), todo_file);
 217         return 0;
 218 }
 219
 220 static int transform_todo_file(unsigned flags)
 221 {
 222         const char *todo_file = rebase_path_todo();
 223         struct todo_list todo_list = TODO_LIST_INIT;
 224         int res;
 225
 226         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 227                 return error_errno(_("could not read '%s'."), todo_file);
 228
 229         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 230                                         &todo_list)) {
 231                 todo_list_release(&todo_list);
 232                 return error(_("unusable todo list: '%s'"), todo_file);
 233         }
 234
 235         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 236                                       NULL, NULL, -1, flags);
 237         todo_list_release(&todo_list);
 238
 239         if (res)
 240                 return error_errno(_("could not write '%s'."), todo_file);
 241         return 0;
 242 }
 243
 244 static int edit_todo_file(unsigned flags)
 245 {
 246         const char *todo_file = rebase_path_todo();
 247         struct todo_list todo_list = TODO_LIST_INIT,
 248                 new_todo = TODO_LIST_INIT;
 249         int res = 0;
 250
 251         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 252                 return error_errno(_("could not read '%s'."), todo_file);
 253
 254         strbuf_stripspace(&todo_list.buf, 1);
 255         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 256         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 257                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 258                 res = error_errno(_("could not write '%s'"), todo_file);
 259
 260         todo_list_release(&todo_list);
 261         todo_list_release(&new_todo);
 262
 263         return res;
 264 }
 265
 266 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 267                                struct object_id *orig_head, const char **head_hash,
 268                                char **revisions, char **shortrevisions)
 269 {
 270         struct commit *base_rev = upstream ? upstream : onto;
 271         const char *shorthead;
 272
 273         *head_hash = find_unique_abbrev(orig_head, GIT_MAX_HEXSZ);
 274         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 275                                                    *head_hash);
 276
 277         shorthead = find_unique_abbrev(orig_head, DEFAULT_ABBREV);
 278
 279         if (upstream) {
 280                 const char *shortrev;
 281
 282                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 283                                               DEFAULT_ABBREV);
 284
 285                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 286         } else
 287                 *shortrevisions = xstrdup(shorthead);
 288
 289         return 0;
 290 }
 291
 292 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 293                             struct commit *onto, const char *orig_head)
 294 {
 295         FILE *interactive;
 296
 297         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 298                 return error_errno(_("could not create temporary %s"), merge_dir());
 299
 300         delete_reflog("REBASE_HEAD");
 301
 302         interactive = fopen(path_interactive(), "w");
 303         if (!interactive)
 304                 return error_errno(_("could not mark as interactive"));
 305         fclose(interactive);
 306
 307         return write_basic_state(opts, head_name, onto, orig_head);
 308 }
 309
 310 static void split_exec_commands(const char *cmd, struct string_list *commands)
 311 {
 312         if (cmd && *cmd) {
 313                 string_list_split(commands, cmd, '\n', -1);
 314
 315                 /* rebase.c adds a new line to cmd after every command,
 316                  * so here the last command is always empty */
 317                 string_list_remove_empty_items(commands, 0);
 318         }
 319 }
 320
 321 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 322 {
 323         int ret;
 324         const char *head_hash = NULL;
 325         char *revisions = NULL, *shortrevisions = NULL;
 326         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 327         struct todo_list todo_list = TODO_LIST_INIT;
 328         struct replay_opts replay = get_replay_opts(opts);
 329         struct string_list commands = STRING_LIST_INIT_DUP;
 330
 331         if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head,
 332                                 &head_hash, &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_pushf(&make_script_args, "^%s",
 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_sequencer_rebase(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_MERGE;
 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_sequencer_rebase(&opts, command);
 556 }
 557
 558 static int is_merge(struct rebase_options *opts)
 559 {
 560         return opts->type == REBASE_MERGE ||
 561                 opts->type == REBASE_PRESERVE_MERGES;
 562 }
 563
 564 static void imply_merge(struct rebase_options *opts, const char *option)
 565 {
 566         switch (opts->type) {
 567         case REBASE_APPLY:
 568                 die(_("%s requires an interactive rebase"), option);
 569                 break;
 570         case REBASE_MERGE:
 571         case REBASE_PRESERVE_MERGES:
 572                 break;
 573         default:
 574                 opts->type = REBASE_MERGE; /* implied */
 575                 break;
 576         }
 577 }
 578
 579 /* Returns the filename prefixed by the state_dir */
 580 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 581 {
 582         static struct strbuf path = STRBUF_INIT;
 583         static size_t prefix_len;
 584
 585         if (!prefix_len) {
 586                 strbuf_addf(&path, "%s/", opts->state_dir);
 587                 prefix_len = path.len;
 588         }
 589
 590         strbuf_setlen(&path, prefix_len);
 591         strbuf_addstr(&path, filename);
 592         return path.buf;
 593 }
 594
 595 /* Read one file, then strip line endings */
 596 static int read_one(const char *path, struct strbuf *buf)
 597 {
 598         if (strbuf_read_file(buf, path, 0) < 0)
 599                 return error_errno(_("could not read '%s'"), path);
 600         strbuf_trim_trailing_newline(buf);
 601         return 0;
 602 }
 603
 604 /* Initialize the rebase options from the state directory. */
 605 static int read_basic_state(struct rebase_options *opts)
 606 {
 607         struct strbuf head_name = STRBUF_INIT;
 608         struct strbuf buf = STRBUF_INIT;
 609         struct object_id oid;
 610
 611         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 612             read_one(state_dir_path("onto", opts), &buf))
 613                 return -1;
 614         opts->head_name = starts_with(head_name.buf, "refs/") ?
 615                 xstrdup(head_name.buf) : NULL;
 616         strbuf_release(&head_name);
 617         if (get_oid(buf.buf, &oid))
 618                 return error(_("could not get 'onto': '%s'"), buf.buf);
 619         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 620
 621         /*
 622          * We always write to orig-head, but interactive rebase used to write to
 623          * head. Fall back to reading from head to cover for the case that the
 624          * user upgraded git with an ongoing interactive rebase.
 625          */
 626         strbuf_reset(&buf);
 627         if (file_exists(state_dir_path("orig-head", opts))) {
 628                 if (read_one(state_dir_path("orig-head", opts), &buf))
 629                         return -1;
 630         } else if (read_one(state_dir_path("head", opts), &buf))
 631                 return -1;
 632         if (get_oid(buf.buf, &opts->orig_head))
 633                 return error(_("invalid orig-head: '%s'"), buf.buf);
 634
 635         if (file_exists(state_dir_path("quiet", opts)))
 636                 opts->flags &= ~REBASE_NO_QUIET;
 637         else
 638                 opts->flags |= REBASE_NO_QUIET;
 639
 640         if (file_exists(state_dir_path("verbose", opts)))
 641                 opts->flags |= REBASE_VERBOSE;
 642
 643         if (file_exists(state_dir_path("signoff", opts))) {
 644                 opts->signoff = 1;
 645                 opts->flags |= REBASE_FORCE;
 646         }
 647
 648         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 649                 strbuf_reset(&buf);
 650                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 651                             &buf))
 652                         return -1;
 653                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 654                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 655                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 656                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 657                 else
 658                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 659                                   "'%s'"), buf.buf);
 660         }
 661
 662         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 663                 strbuf_reset(&buf);
 664                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 665                             &buf))
 666                         return -1;
 667                 free(opts->gpg_sign_opt);
 668                 opts->gpg_sign_opt = xstrdup(buf.buf);
 669         }
 670
 671         if (file_exists(state_dir_path("strategy", opts))) {
 672                 strbuf_reset(&buf);
 673                 if (read_one(state_dir_path("strategy", opts), &buf))
 674                         return -1;
 675                 free(opts->strategy);
 676                 opts->strategy = xstrdup(buf.buf);
 677         }
 678
 679         if (file_exists(state_dir_path("strategy_opts", opts))) {
 680                 strbuf_reset(&buf);
 681                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 682                         return -1;
 683                 free(opts->strategy_opts);
 684                 opts->strategy_opts = xstrdup(buf.buf);
 685         }
 686
 687         strbuf_release(&buf);
 688
 689         return 0;
 690 }
 691
 692 static int rebase_write_basic_state(struct rebase_options *opts)
 693 {
 694         write_file(state_dir_path("head-name", opts), "%s",
 695                    opts->head_name ? opts->head_name : "detached HEAD");
 696         write_file(state_dir_path("onto", opts), "%s",
 697                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 698         write_file(state_dir_path("orig-head", opts), "%s",
 699                    oid_to_hex(&opts->orig_head));
 700         if (!(opts->flags & REBASE_NO_QUIET))
 701                 write_file(state_dir_path("quiet", opts), "%s", "");
 702         if (opts->flags & REBASE_VERBOSE)
 703                 write_file(state_dir_path("verbose", opts), "%s", "");
 704         if (opts->strategy)
 705                 write_file(state_dir_path("strategy", opts), "%s",
 706                            opts->strategy);
 707         if (opts->strategy_opts)
 708                 write_file(state_dir_path("strategy_opts", opts), "%s",
 709                            opts->strategy_opts);
 710         if (opts->allow_rerere_autoupdate > 0)
 711                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 712                            "-%s-rerere-autoupdate",
 713                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 714                                 "" : "-no");
 715         if (opts->gpg_sign_opt)
 716                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 717                            opts->gpg_sign_opt);
 718         if (opts->signoff)
 719                 write_file(state_dir_path("signoff", opts), "--signoff");
 720
 721         return 0;
 722 }
 723
 724 static int apply_autostash(struct rebase_options *opts)
 725 {
 726         const char *path = state_dir_path("autostash", opts);
 727         struct strbuf autostash = STRBUF_INIT;
 728         struct child_process stash_apply = CHILD_PROCESS_INIT;
 729
 730         if (!file_exists(path))
 731                 return 0;
 732
 733         if (read_one(path, &autostash))
 734                 return error(_("Could not read '%s'"), path);
 735         /* Ensure that the hash is not mistaken for a number */
 736         strbuf_addstr(&autostash, "^0");
 737         argv_array_pushl(&stash_apply.args,
 738                          "stash", "apply", autostash.buf, NULL);
 739         stash_apply.git_cmd = 1;
 740         stash_apply.no_stderr = stash_apply.no_stdout =
 741                 stash_apply.no_stdin = 1;
 742         if (!run_command(&stash_apply))
 743                 printf(_("Applied autostash.\n"));
 744         else {
 745                 struct argv_array args = ARGV_ARRAY_INIT;
 746                 int res = 0;
 747
 748                 argv_array_pushl(&args,
 749                                  "stash", "store", "-m", "autostash", "-q",
 750                                  autostash.buf, NULL);
 751                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 752                         res = error(_("Cannot store %s"), autostash.buf);
 753                 argv_array_clear(&args);
 754                 strbuf_release(&autostash);
 755                 if (res)
 756                         return res;
 757
 758                 fprintf(stderr,
 759                         _("Applying autostash resulted in conflicts.\n"
 760                           "Your changes are safe in the stash.\n"
 761                           "You can run \"git stash pop\" or \"git stash drop\" "
 762                           "at any time.\n"));
 763         }
 764
 765         strbuf_release(&autostash);
 766         return 0;
 767 }
 768
 769 static int finish_rebase(struct rebase_options *opts)
 770 {
 771         struct strbuf dir = STRBUF_INIT;
 772         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 773         int ret = 0;
 774
 775         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 776         apply_autostash(opts);
 777         close_object_store(the_repository->objects);
 778         /*
 779          * We ignore errors in 'gc --auto', since the
 780          * user should see them.
 781          */
 782         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 783         if (opts->type == REBASE_MERGE) {
 784                 struct replay_opts replay = REPLAY_OPTS_INIT;
 785
 786                 replay.action = REPLAY_INTERACTIVE_REBASE;
 787                 ret = sequencer_remove_state(&replay);
 788         } else {
 789                 strbuf_addstr(&dir, opts->state_dir);
 790                 if (remove_dir_recursively(&dir, 0))
 791                         ret = error(_("could not remove '%s'"),
 792                                     opts->state_dir);
 793                 strbuf_release(&dir);
 794         }
 795
 796         return ret;
 797 }
 798
 799 static struct commit *peel_committish(const char *name)
 800 {
 801         struct object *obj;
 802         struct object_id oid;
 803
 804         if (get_oid(name, &oid))
 805                 return NULL;
 806         obj = parse_object(the_repository, &oid);
 807         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 808 }
 809
 810 static void add_var(struct strbuf *buf, const char *name, const char *value)
 811 {
 812         if (!value)
 813                 strbuf_addf(buf, "unset %s; ", name);
 814         else {
 815                 strbuf_addf(buf, "%s=", name);
 816                 sq_quote_buf(buf, value);
 817                 strbuf_addstr(buf, "; ");
 818         }
 819 }
 820
 821 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 822
 823 #define RESET_HEAD_DETACH (1<<0)
 824 #define RESET_HEAD_HARD (1<<1)
 825 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 826 #define RESET_HEAD_REFS_ONLY (1<<3)
 827 #define RESET_ORIG_HEAD (1<<4)
 828
 829 static int reset_head(struct object_id *oid, const char *action,
 830                       const char *switch_to_branch, unsigned flags,
 831                       const char *reflog_orig_head, const char *reflog_head)
 832 {
 833         unsigned detach_head = flags & RESET_HEAD_DETACH;
 834         unsigned reset_hard = flags & RESET_HEAD_HARD;
 835         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 836         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 837         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 838         struct object_id head_oid;
 839         struct tree_desc desc[2] = { { NULL }, { NULL } };
 840         struct lock_file lock = LOCK_INIT;
 841         struct unpack_trees_options unpack_tree_opts;
 842         struct tree *tree;
 843         const char *reflog_action;
 844         struct strbuf msg = STRBUF_INIT;
 845         size_t prefix_len;
 846         struct object_id *orig = NULL, oid_orig,
 847                 *old_orig = NULL, oid_old_orig;
 848         int ret = 0, nr = 0;
 849
 850         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 851                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 852
 853         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 854                 ret = -1;
 855                 goto leave_reset_head;
 856         }
 857
 858         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 859                 ret = error(_("could not determine HEAD revision"));
 860                 goto leave_reset_head;
 861         }
 862
 863         if (!oid)
 864                 oid = &head_oid;
 865
 866         if (refs_only)
 867                 goto reset_head_refs;
 868
 869         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 870         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 871         unpack_tree_opts.head_idx = 1;
 872         unpack_tree_opts.src_index = the_repository->index;
 873         unpack_tree_opts.dst_index = the_repository->index;
 874         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 875         unpack_tree_opts.update = 1;
 876         unpack_tree_opts.merge = 1;
 877         init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
 878         if (!detach_head)
 879                 unpack_tree_opts.reset = 1;
 880
 881         if (repo_read_index_unmerged(the_repository) < 0) {
 882                 ret = error(_("could not read index"));
 883                 goto leave_reset_head;
 884         }
 885
 886         if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 887                 ret = error(_("failed to find tree of %s"),
 888                             oid_to_hex(&head_oid));
 889                 goto leave_reset_head;
 890         }
 891
 892         if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 893                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 894                 goto leave_reset_head;
 895         }
 896
 897         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 898                 ret = -1;
 899                 goto leave_reset_head;
 900         }
 901
 902         tree = parse_tree_indirect(oid);
 903         prime_cache_tree(the_repository, the_repository->index, tree);
 904
 905         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 906                 ret = error(_("could not write index"));
 907                 goto leave_reset_head;
 908         }
 909
 910 reset_head_refs:
 911         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 912         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 913         prefix_len = msg.len;
 914
 915         if (update_orig_head) {
 916                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 917                         old_orig = &oid_old_orig;
 918                 if (!get_oid("HEAD", &oid_orig)) {
 919                         orig = &oid_orig;
 920                         if (!reflog_orig_head) {
 921                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 922                                 reflog_orig_head = msg.buf;
 923                         }
 924                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 925                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 926                 } else if (old_orig)
 927                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 928         }
 929
 930         if (!reflog_head) {
 931                 strbuf_setlen(&msg, prefix_len);
 932                 strbuf_addstr(&msg, "updating HEAD");
 933                 reflog_head = msg.buf;
 934         }
 935         if (!switch_to_branch)
 936                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 937                                  detach_head ? REF_NO_DEREF : 0,
 938                                  UPDATE_REFS_MSG_ON_ERR);
 939         else {
 940                 ret = update_ref(reflog_head, switch_to_branch, oid,
 941                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 942                 if (!ret)
 943                         ret = create_symref("HEAD", switch_to_branch,
 944                                             reflog_head);
 945         }
 946         if (run_hook)
 947                 run_hook_le(NULL, "post-checkout",
 948                             oid_to_hex(orig ? orig : &null_oid),
 949                             oid_to_hex(oid), "1", NULL);
 950
 951 leave_reset_head:
 952         strbuf_release(&msg);
 953         rollback_lock_file(&lock);
 954         while (nr)
 955                 free((void *)desc[--nr].buffer);
 956         return ret;
 957 }
 958
 959 static int move_to_original_branch(struct rebase_options *opts)
 960 {
 961         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 962         int ret;
 963
 964         if (!opts->head_name)
 965                 return 0; /* nothing to move back to */
 966
 967         if (!opts->onto)
 968                 BUG("move_to_original_branch without onto");
 969
 970         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 971                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 972         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 973                     opts->head_name);
 974         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 975                          orig_head_reflog.buf, head_reflog.buf);
 976
 977         strbuf_release(&orig_head_reflog);
 978         strbuf_release(&head_reflog);
 979         return ret;
 980 }
 981
 982 static const char *resolvemsg =
 983 N_("Resolve all conflicts manually, mark them as resolved with\n"
 984 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 985 "You can instead skip this commit: run \"git rebase --skip\".\n"
 986 "To abort and get back to the state before \"git rebase\", run "
 987 "\"git rebase --abort\".");
 988
 989 static int run_am(struct rebase_options *opts)
 990 {
 991         struct child_process am = CHILD_PROCESS_INIT;
 992         struct child_process format_patch = CHILD_PROCESS_INIT;
 993         struct strbuf revisions = STRBUF_INIT;
 994         int status;
 995         char *rebased_patches;
 996
 997         am.git_cmd = 1;
 998         argv_array_push(&am.args, "am");
 999
1000         if (opts->action && !strcmp("continue", opts->action)) {
1001                 argv_array_push(&am.args, "--resolved");
1002                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1003                 if (opts->gpg_sign_opt)
1004                         argv_array_push(&am.args, opts->gpg_sign_opt);
1005                 status = run_command(&am);
1006                 if (status)
1007                         return status;
1008
1009                 return move_to_original_branch(opts);
1010         }
1011         if (opts->action && !strcmp("skip", opts->action)) {
1012                 argv_array_push(&am.args, "--skip");
1013                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1014                 status = run_command(&am);
1015                 if (status)
1016                         return status;
1017
1018                 return move_to_original_branch(opts);
1019         }
1020         if (opts->action && !strcmp("show-current-patch", opts->action)) {
1021                 argv_array_push(&am.args, "--show-current-patch");
1022                 return run_command(&am);
1023         }
1024
1025         strbuf_addf(&revisions, "%s...%s",
1026                     oid_to_hex(opts->root ?
1027                                /* this is now equivalent to !opts->upstream */
1028                                &opts->onto->object.oid :
1029                                &opts->upstream->object.oid),
1030                     oid_to_hex(&opts->orig_head));
1031
1032         rebased_patches = xstrdup(git_path("rebased-patches"));
1033         format_patch.out = open(rebased_patches,
1034                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1035         if (format_patch.out < 0) {
1036                 status = error_errno(_("could not open '%s' for writing"),
1037                                      rebased_patches);
1038                 free(rebased_patches);
1039                 argv_array_clear(&am.args);
1040                 return status;
1041         }
1042
1043         format_patch.git_cmd = 1;
1044         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1045                          "--full-index", "--cherry-pick", "--right-only",
1046                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1047                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
1048                          "--no-base", NULL);
1049         if (opts->git_format_patch_opt.len)
1050                 argv_array_split(&format_patch.args,
1051                                  opts->git_format_patch_opt.buf);
1052         argv_array_push(&format_patch.args, revisions.buf);
1053         if (opts->restrict_revision)
1054                 argv_array_pushf(&format_patch.args, "^%s",
1055                                  oid_to_hex(&opts->restrict_revision->object.oid));
1056
1057         status = run_command(&format_patch);
1058         if (status) {
1059                 unlink(rebased_patches);
1060                 free(rebased_patches);
1061                 argv_array_clear(&am.args);
1062
1063                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1064                            "HEAD", NULL);
1065                 error(_("\ngit encountered an error while preparing the "
1066                         "patches to replay\n"
1067                         "these revisions:\n"
1068                         "\n    %s\n\n"
1069                         "As a result, git cannot rebase them."),
1070                       opts->revisions);
1071
1072                 strbuf_release(&revisions);
1073                 return status;
1074         }
1075         strbuf_release(&revisions);
1076
1077         am.in = open(rebased_patches, O_RDONLY);
1078         if (am.in < 0) {
1079                 status = error_errno(_("could not open '%s' for reading"),
1080                                      rebased_patches);
1081                 free(rebased_patches);
1082                 argv_array_clear(&am.args);
1083                 return status;
1084         }
1085
1086         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1087         argv_array_push(&am.args, "--rebasing");
1088         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1089         argv_array_push(&am.args, "--patch-format=mboxrd");
1090         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1091                 argv_array_push(&am.args, "--rerere-autoupdate");
1092         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1093                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1094         if (opts->gpg_sign_opt)
1095                 argv_array_push(&am.args, opts->gpg_sign_opt);
1096         status = run_command(&am);
1097         unlink(rebased_patches);
1098         free(rebased_patches);
1099
1100         if (!status) {
1101                 return move_to_original_branch(opts);
1102         }
1103
1104         if (is_directory(opts->state_dir))
1105                 rebase_write_basic_state(opts);
1106
1107         return status;
1108 }
1109
1110 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1111 {
1112         const char *argv[] = { NULL, NULL };
1113         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1114         int status;
1115         const char *backend, *backend_func;
1116
1117         if (opts->type == REBASE_MERGE) {
1118                 /* Run sequencer-based rebase */
1119                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1120                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1121                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1122                         opts->autosquash = 0;
1123                 }
1124                 if (opts->gpg_sign_opt) {
1125                         /* remove the leading "-S" */
1126                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1127                         free(opts->gpg_sign_opt);
1128                         opts->gpg_sign_opt = tmp;
1129                 }
1130
1131                 status = run_sequencer_rebase(opts, action);
1132                 goto finished_rebase;
1133         }
1134
1135         if (opts->type == REBASE_APPLY) {
1136                 status = run_am(opts);
1137                 goto finished_rebase;
1138         }
1139
1140         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1141         add_var(&script_snippet, "state_dir", opts->state_dir);
1142
1143         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1144         add_var(&script_snippet, "upstream", opts->upstream ?
1145                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1146         add_var(&script_snippet, "head_name",
1147                 opts->head_name ? opts->head_name : "detached HEAD");
1148         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1149         add_var(&script_snippet, "onto", opts->onto ?
1150                 oid_to_hex(&opts->onto->object.oid) : NULL);
1151         add_var(&script_snippet, "onto_name", opts->onto_name);
1152         add_var(&script_snippet, "revisions", opts->revisions);
1153         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1154                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1155         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1156         add_var(&script_snippet, "git_am_opt", buf.buf);
1157         strbuf_release(&buf);
1158         add_var(&script_snippet, "verbose",
1159                 opts->flags & REBASE_VERBOSE ? "t" : "");
1160         add_var(&script_snippet, "diffstat",
1161                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1162         add_var(&script_snippet, "force_rebase",
1163                 opts->flags & REBASE_FORCE ? "t" : "");
1164         if (opts->switch_to)
1165                 add_var(&script_snippet, "switch_to", opts->switch_to);
1166         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1167         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1168         add_var(&script_snippet, "allow_rerere_autoupdate",
1169                 opts->allow_rerere_autoupdate ?
1170                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1171                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1172         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1173         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1174         add_var(&script_snippet, "cmd", opts->cmd);
1175         add_var(&script_snippet, "allow_empty_message",
1176                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1177         add_var(&script_snippet, "rebase_merges",
1178                 opts->rebase_merges ? "t" : "");
1179         add_var(&script_snippet, "rebase_cousins",
1180                 opts->rebase_cousins ? "t" : "");
1181         add_var(&script_snippet, "strategy", opts->strategy);
1182         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1183         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1184         add_var(&script_snippet, "squash_onto",
1185                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1186         add_var(&script_snippet, "git_format_patch_opt",
1187                 opts->git_format_patch_opt.buf);
1188
1189         if (is_merge(opts) &&
1190             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1191                 strbuf_addstr(&script_snippet,
1192                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1193                 opts->autosquash = 0;
1194         }
1195
1196         switch (opts->type) {
1197         case REBASE_PRESERVE_MERGES:
1198                 backend = "git-rebase--preserve-merges";
1199                 backend_func = "git_rebase__preserve_merges";
1200                 break;
1201         default:
1202                 BUG("Unhandled rebase type %d", opts->type);
1203                 break;
1204         }
1205
1206         strbuf_addf(&script_snippet,
1207                     ". git-sh-setup && . %s && %s", backend, backend_func);
1208         argv[0] = script_snippet.buf;
1209
1210         status = run_command_v_opt(argv, RUN_USING_SHELL);
1211 finished_rebase:
1212         if (opts->dont_finish_rebase)
1213                 ; /* do nothing */
1214         else if (opts->type == REBASE_MERGE)
1215                 ; /* merge backend cleans up after itself */
1216         else if (status == 0) {
1217                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1218                         finish_rebase(opts);
1219         } else if (status == 2) {
1220                 struct strbuf dir = STRBUF_INIT;
1221
1222                 apply_autostash(opts);
1223                 strbuf_addstr(&dir, opts->state_dir);
1224                 remove_dir_recursively(&dir, 0);
1225                 strbuf_release(&dir);
1226                 die("Nothing to do");
1227         }
1228
1229         strbuf_release(&script_snippet);
1230
1231         return status ? -1 : 0;
1232 }
1233
1234 static int rebase_config(const char *var, const char *value, void *data)
1235 {
1236         struct rebase_options *opts = data;
1237
1238         if (!strcmp(var, "rebase.stat")) {
1239                 if (git_config_bool(var, value))
1240                         opts->flags |= REBASE_DIFFSTAT;
1241                 else
1242                         opts->flags &= ~REBASE_DIFFSTAT;
1243                 return 0;
1244         }
1245
1246         if (!strcmp(var, "rebase.autosquash")) {
1247                 opts->autosquash = git_config_bool(var, value);
1248                 return 0;
1249         }
1250
1251         if (!strcmp(var, "commit.gpgsign")) {
1252                 free(opts->gpg_sign_opt);
1253                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1254                         xstrdup("-S") : NULL;
1255                 return 0;
1256         }
1257
1258         if (!strcmp(var, "rebase.autostash")) {
1259                 opts->autostash = git_config_bool(var, value);
1260                 return 0;
1261         }
1262
1263         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1264                 opts->reschedule_failed_exec = git_config_bool(var, value);
1265                 return 0;
1266         }
1267
1268         if (!strcmp(var, "rebase.usebuiltin")) {
1269                 opts->use_legacy_rebase = !git_config_bool(var, value);
1270                 return 0;
1271         }
1272
1273         if (!strcmp(var, "rebase.backend")) {
1274                 return git_config_string(&opts->default_backend, var, value);
1275         }
1276
1277         return git_default_config(var, value, data);
1278 }
1279
1280 /*
1281  * Determines whether the commits in from..to are linear, i.e. contain
1282  * no merge commits. This function *expects* `from` to be an ancestor of
1283  * `to`.
1284  */
1285 static int is_linear_history(struct commit *from, struct commit *to)
1286 {
1287         while (to && to != from) {
1288                 parse_commit(to);
1289                 if (!to->parents)
1290                         return 1;
1291                 if (to->parents->next)
1292                         return 0;
1293                 to = to->parents->item;
1294         }
1295         return 1;
1296 }
1297
1298 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1299                             struct commit *restrict_revision,
1300                             struct object_id *head_oid, struct object_id *merge_base)
1301 {
1302         struct commit *head = lookup_commit(the_repository, head_oid);
1303         struct commit_list *merge_bases = NULL;
1304         int res = 0;
1305
1306         if (!head)
1307                 goto done;
1308
1309         merge_bases = get_merge_bases(onto, head);
1310         if (!merge_bases || merge_bases->next) {
1311                 oidcpy(merge_base, &null_oid);
1312                 goto done;
1313         }
1314
1315         oidcpy(merge_base, &merge_bases->item->object.oid);
1316         if (!oideq(merge_base, &onto->object.oid))
1317                 goto done;
1318
1319         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1320                 goto done;
1321
1322         if (!upstream)
1323                 goto done;
1324
1325         free_commit_list(merge_bases);
1326         merge_bases = get_merge_bases(upstream, head);
1327         if (!merge_bases || merge_bases->next)
1328                 goto done;
1329
1330         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1331                 goto done;
1332
1333         res = 1;
1334
1335 done:
1336         free_commit_list(merge_bases);
1337         return res && is_linear_history(onto, head);
1338 }
1339
1340 static int parse_opt_am(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         opts->type = REBASE_APPLY;
1348
1349         return 0;
1350 }
1351
1352 /* -i followed by -m is still -i */
1353 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1354 {
1355         struct rebase_options *opts = opt->value;
1356
1357         BUG_ON_OPT_NEG(unset);
1358         BUG_ON_OPT_ARG(arg);
1359
1360         if (!is_merge(opts))
1361                 opts->type = REBASE_MERGE;
1362
1363         return 0;
1364 }
1365
1366 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1367 static int parse_opt_interactive(const struct option *opt, const char *arg,
1368                                  int unset)
1369 {
1370         struct rebase_options *opts = opt->value;
1371
1372         BUG_ON_OPT_NEG(unset);
1373         BUG_ON_OPT_ARG(arg);
1374
1375         opts->type = REBASE_MERGE;
1376         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1377
1378         return 0;
1379 }
1380
1381 static enum empty_type parse_empty_value(const char *value)
1382 {
1383         if (!strcasecmp(value, "drop"))
1384                 return EMPTY_DROP;
1385         else if (!strcasecmp(value, "keep"))
1386                 return EMPTY_KEEP;
1387         else if (!strcasecmp(value, "ask"))
1388                 return EMPTY_ASK;
1389
1390         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
1391 }
1392
1393 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
1394 {
1395         struct rebase_options *options = opt->value;
1396         enum empty_type value = parse_empty_value(arg);
1397
1398         BUG_ON_OPT_NEG(unset);
1399
1400         options->empty = value;
1401         return 0;
1402 }
1403
1404 static void NORETURN error_on_missing_default_upstream(void)
1405 {
1406         struct branch *current_branch = branch_get(NULL);
1407
1408         printf(_("%s\n"
1409                  "Please specify which branch you want to rebase against.\n"
1410                  "See git-rebase(1) for details.\n"
1411                  "\n"
1412                  "    git rebase '<branch>'\n"
1413                  "\n"),
1414                 current_branch ? _("There is no tracking information for "
1415                         "the current branch.") :
1416                         _("You are not currently on a branch."));
1417
1418         if (current_branch) {
1419                 const char *remote = current_branch->remote_name;
1420
1421                 if (!remote)
1422                         remote = _("<remote>");
1423
1424                 printf(_("If you wish to set tracking information for this "
1425                          "branch you can do so with:\n"
1426                          "\n"
1427                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1428                          "\n"),
1429                        remote, current_branch->name);
1430         }
1431         exit(1);
1432 }
1433
1434 static void set_reflog_action(struct rebase_options *options)
1435 {
1436         const char *env;
1437         struct strbuf buf = STRBUF_INIT;
1438
1439         if (!is_merge(options))
1440                 return;
1441
1442         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1443         if (env && strcmp("rebase", env))
1444                 return; /* only override it if it is "rebase" */
1445
1446         strbuf_addf(&buf, "rebase (%s)", options->action);
1447         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1448         strbuf_release(&buf);
1449 }
1450
1451 static int check_exec_cmd(const char *cmd)
1452 {
1453         if (strchr(cmd, '\n'))
1454                 return error(_("exec commands cannot contain newlines"));
1455
1456         /* Does the command consist purely of whitespace? */
1457         if (!cmd[strspn(cmd, " \t\r\f\v")])
1458                 return error(_("empty exec command"));
1459
1460         return 0;
1461 }
1462
1463
1464 int cmd_rebase(int argc, const char **argv, const char *prefix)
1465 {
1466         struct rebase_options options = REBASE_OPTIONS_INIT;
1467         const char *branch_name;
1468         int ret, flags, total_argc, in_progress = 0;
1469         int keep_base = 0;
1470         int ok_to_skip_pre_rebase = 0;
1471         struct strbuf msg = STRBUF_INIT;
1472         struct strbuf revisions = STRBUF_INIT;
1473         struct strbuf buf = STRBUF_INIT;
1474         struct object_id merge_base;
1475         int ignore_whitespace = 0;
1476         enum action action = ACTION_NONE;
1477         const char *gpg_sign = NULL;
1478         struct string_list exec = STRING_LIST_INIT_NODUP;
1479         const char *rebase_merges = NULL;
1480         int fork_point = -1;
1481         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1482         struct object_id squash_onto;
1483         char *squash_onto_name = NULL;
1484         int reschedule_failed_exec = -1;
1485         int allow_preemptive_ff = 1;
1486         struct option builtin_rebase_options[] = {
1487                 OPT_STRING(0, "onto", &options.onto_name,
1488                            N_("revision"),
1489                            N_("rebase onto given branch instead of upstream")),
1490                 OPT_BOOL(0, "keep-base", &keep_base,
1491                          N_("use the merge-base of upstream and branch as the current base")),
1492                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1493                          N_("allow pre-rebase hook to run")),
1494                 OPT_NEGBIT('q', "quiet", &options.flags,
1495                            N_("be quiet. implies --no-stat"),
1496                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1497                 OPT_BIT('v', "verbose", &options.flags,
1498                         N_("display a diffstat of what changed upstream"),
1499                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1500                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1501                         N_("do not show diffstat of what changed upstream"),
1502                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1503                 OPT_BOOL(0, "signoff", &options.signoff,
1504                          N_("add a Signed-off-by: line to each commit")),
1505                 OPT_BOOL(0, "committer-date-is-author-date",
1506                          &options.committer_date_is_author_date,
1507                          N_("make committer date match author date")),
1508                 OPT_BOOL(0, "ignore-date", &options.ignore_date,
1509                          N_("ignore author date and use current date")),
1510                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1511                                   N_("passed to 'git apply'"), 0),
1512                 OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
1513                          N_("ignore changes in whitespace")),
1514                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1515                                   N_("action"), N_("passed to 'git apply'"), 0),
1516                 OPT_BIT('f', "force-rebase", &options.flags,
1517                         N_("cherry-pick all commits, even if unchanged"),
1518                         REBASE_FORCE),
1519                 OPT_BIT(0, "no-ff", &options.flags,
1520                         N_("cherry-pick all commits, even if unchanged"),
1521                         REBASE_FORCE),
1522                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1523                             ACTION_CONTINUE),
1524                 OPT_CMDMODE(0, "skip", &action,
1525                             N_("skip current patch and continue"), ACTION_SKIP),
1526                 OPT_CMDMODE(0, "abort", &action,
1527                             N_("abort and check out the original branch"),
1528                             ACTION_ABORT),
1529                 OPT_CMDMODE(0, "quit", &action,
1530                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1531                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1532                             "during an interactive rebase"), ACTION_EDIT_TODO),
1533                 OPT_CMDMODE(0, "show-current-patch", &action,
1534                             N_("show the patch file being applied or merged"),
1535                             ACTION_SHOW_CURRENT_PATCH),
1536                 { OPTION_CALLBACK, 0, "apply", &options, NULL,
1537                         N_("use apply strategies to rebase"),
1538                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1539                         parse_opt_am },
1540                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1541                         N_("use merging strategies to rebase"),
1542                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1543                         parse_opt_merge },
1544                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1545                         N_("let the user edit the list of commits to rebase"),
1546                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1547                         parse_opt_interactive },
1548                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1549                               N_("(DEPRECATED) try to recreate merges instead of "
1550                                  "ignoring them"),
1551                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1552                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1553                 OPT_CALLBACK_F(0, "empty", &options, "{drop,keep,ask}",
1554                                N_("how to handle commits that become empty"),
1555                                PARSE_OPT_NONEG, parse_opt_empty),
1556                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
1557                         N_("(DEPRECATED) keep empty commits"),
1558                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1559                         parse_opt_keep_empty },
1560                 OPT_BOOL(0, "autosquash", &options.autosquash,
1561                          N_("move commits that begin with "
1562                             "squash!/fixup! under -i")),
1563                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1564                         N_("GPG-sign commits"),
1565                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1566                 OPT_BOOL(0, "autostash", &options.autostash,
1567                          N_("automatically stash/stash pop before and after")),
1568                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1569                                 N_("add exec lines after each commit of the "
1570                                    "editable list")),
1571                 OPT_BOOL_F(0, "allow-empty-message",
1572                            &options.allow_empty_message,
1573                            N_("allow rebasing commits with empty messages"),
1574                            PARSE_OPT_HIDDEN),
1575                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1576                         N_("mode"),
1577                         N_("try to rebase merges instead of skipping them"),
1578                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1579                 OPT_BOOL(0, "fork-point", &fork_point,
1580                          N_("use 'merge-base --fork-point' to refine upstream")),
1581                 OPT_STRING('s', "strategy", &options.strategy,
1582                            N_("strategy"), N_("use the given merge strategy")),
1583                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1584                                 N_("option"),
1585                                 N_("pass the argument through to the merge "
1586                                    "strategy")),
1587                 OPT_BOOL(0, "root", &options.root,
1588                          N_("rebase all reachable commits up to the root(s)")),
1589                 OPT_BOOL(0, "reschedule-failed-exec",
1590                          &reschedule_failed_exec,
1591                          N_("automatically re-schedule any `exec` that fails")),
1592                 OPT_END(),
1593         };
1594         int i;
1595
1596         if (argc == 2 && !strcmp(argv[1], "-h"))
1597                 usage_with_options(builtin_rebase_usage,
1598                                    builtin_rebase_options);
1599
1600         options.allow_empty_message = 1;
1601         git_config(rebase_config, &options);
1602
1603         if (options.use_legacy_rebase ||
1604             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1605                 warning(_("the rebase.useBuiltin support has been removed!\n"
1606                           "See its entry in 'git help config' for details."));
1607
1608         strbuf_reset(&buf);
1609         strbuf_addf(&buf, "%s/applying", apply_dir());
1610         if(file_exists(buf.buf))
1611                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1612
1613         if (is_directory(apply_dir())) {
1614                 options.type = REBASE_APPLY;
1615                 options.state_dir = apply_dir();
1616         } else if (is_directory(merge_dir())) {
1617                 strbuf_reset(&buf);
1618                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1619                 if (is_directory(buf.buf)) {
1620                         options.type = REBASE_PRESERVE_MERGES;
1621                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1622                 } else {
1623                         strbuf_reset(&buf);
1624                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1625                         if(file_exists(buf.buf)) {
1626                                 options.type = REBASE_MERGE;
1627                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1628                         } else
1629                                 options.type = REBASE_MERGE;
1630                 }
1631                 options.state_dir = merge_dir();
1632         }
1633
1634         if (options.type != REBASE_UNSPECIFIED)
1635                 in_progress = 1;
1636
1637         total_argc = argc;
1638         argc = parse_options(argc, argv, prefix,
1639                              builtin_rebase_options,
1640                              builtin_rebase_usage, 0);
1641
1642         if (action != ACTION_NONE && total_argc != 2) {
1643                 usage_with_options(builtin_rebase_usage,
1644                                    builtin_rebase_options);
1645         }
1646
1647         if (argc > 2)
1648                 usage_with_options(builtin_rebase_usage,
1649                                    builtin_rebase_options);
1650
1651         if (options.type == REBASE_PRESERVE_MERGES)
1652                 warning(_("git rebase --preserve-merges is deprecated. "
1653                           "Use --rebase-merges instead."));
1654
1655         if (keep_base) {
1656                 if (options.onto_name)
1657                         die(_("cannot combine '--keep-base' with '--onto'"));
1658                 if (options.root)
1659                         die(_("cannot combine '--keep-base' with '--root'"));
1660         }
1661
1662         if (action != ACTION_NONE && !in_progress)
1663                 die(_("No rebase in progress?"));
1664         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1665
1666         if (action == ACTION_EDIT_TODO && !is_merge(&options))
1667                 die(_("The --edit-todo action can only be used during "
1668                       "interactive rebase."));
1669
1670         if (trace2_is_enabled()) {
1671                 if (is_merge(&options))
1672                         trace2_cmd_mode("interactive");
1673                 else if (exec.nr)
1674                         trace2_cmd_mode("interactive-exec");
1675                 else
1676                         trace2_cmd_mode(action_names[action]);
1677         }
1678
1679         switch (action) {
1680         case ACTION_CONTINUE: {
1681                 struct object_id head;
1682                 struct lock_file lock_file = LOCK_INIT;
1683                 int fd;
1684
1685                 options.action = "continue";
1686                 set_reflog_action(&options);
1687
1688                 /* Sanity check */
1689                 if (get_oid("HEAD", &head))
1690                         die(_("Cannot read HEAD"));
1691
1692                 fd = hold_locked_index(&lock_file, 0);
1693                 if (repo_read_index(the_repository) < 0)
1694                         die(_("could not read index"));
1695                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1696                               NULL);
1697                 if (0 <= fd)
1698                         repo_update_index_if_able(the_repository, &lock_file);
1699                 rollback_lock_file(&lock_file);
1700
1701                 if (has_unstaged_changes(the_repository, 1)) {
1702                         puts(_("You must edit all merge conflicts and then\n"
1703                                "mark them as resolved using git add"));
1704                         exit(1);
1705                 }
1706                 if (read_basic_state(&options))
1707                         exit(1);
1708                 goto run_rebase;
1709         }
1710         case ACTION_SKIP: {
1711                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1712
1713                 options.action = "skip";
1714                 set_reflog_action(&options);
1715
1716                 rerere_clear(the_repository, &merge_rr);
1717                 string_list_clear(&merge_rr, 1);
1718
1719                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1720                                NULL, NULL) < 0)
1721                         die(_("could not discard worktree changes"));
1722                 remove_branch_state(the_repository, 0);
1723                 if (read_basic_state(&options))
1724                         exit(1);
1725                 goto run_rebase;
1726         }
1727         case ACTION_ABORT: {
1728                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1729                 options.action = "abort";
1730                 set_reflog_action(&options);
1731
1732                 rerere_clear(the_repository, &merge_rr);
1733                 string_list_clear(&merge_rr, 1);
1734
1735                 if (read_basic_state(&options))
1736                         exit(1);
1737                 if (reset_head(&options.orig_head, "reset",
1738                                options.head_name, RESET_HEAD_HARD,
1739                                NULL, NULL) < 0)
1740                         die(_("could not move back to %s"),
1741                             oid_to_hex(&options.orig_head));
1742                 remove_branch_state(the_repository, 0);
1743                 ret = !!finish_rebase(&options);
1744                 goto cleanup;
1745         }
1746         case ACTION_QUIT: {
1747                 if (options.type == REBASE_MERGE) {
1748                         struct replay_opts replay = REPLAY_OPTS_INIT;
1749
1750                         replay.action = REPLAY_INTERACTIVE_REBASE;
1751                         ret = !!sequencer_remove_state(&replay);
1752                 } else {
1753                         strbuf_reset(&buf);
1754                         strbuf_addstr(&buf, options.state_dir);
1755                         ret = !!remove_dir_recursively(&buf, 0);
1756                         if (ret)
1757                                 error(_("could not remove '%s'"),
1758                                        options.state_dir);
1759                 }
1760                 goto cleanup;
1761         }
1762         case ACTION_EDIT_TODO:
1763                 options.action = "edit-todo";
1764                 options.dont_finish_rebase = 1;
1765                 goto run_rebase;
1766         case ACTION_SHOW_CURRENT_PATCH:
1767                 options.action = "show-current-patch";
1768                 options.dont_finish_rebase = 1;
1769                 goto run_rebase;
1770         case ACTION_NONE:
1771                 break;
1772         default:
1773                 BUG("action: %d", action);
1774         }
1775
1776         /* Make sure no rebase is in progress */
1777         if (in_progress) {
1778                 const char *last_slash = strrchr(options.state_dir, '/');
1779                 const char *state_dir_base =
1780                         last_slash ? last_slash + 1 : options.state_dir;
1781                 const char *cmd_live_rebase =
1782                         "git rebase (--continue | --abort | --skip)";
1783                 strbuf_reset(&buf);
1784                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1785                 die(_("It seems that there is already a %s directory, and\n"
1786                       "I wonder if you are in the middle of another rebase.  "
1787                       "If that is the\n"
1788                       "case, please try\n\t%s\n"
1789                       "If that is not the case, please\n\t%s\n"
1790                       "and run me again.  I am stopping in case you still "
1791                       "have something\n"
1792                       "valuable there.\n"),
1793                     state_dir_base, cmd_live_rebase, buf.buf);
1794         }
1795
1796         if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
1797             (action != ACTION_NONE) ||
1798             (exec.nr > 0) ||
1799             options.autosquash) {
1800                 allow_preemptive_ff = 0;
1801         }
1802         if (options.committer_date_is_author_date || options.ignore_date)
1803                 options.flags |= REBASE_FORCE;
1804
1805         for (i = 0; i < options.git_am_opts.argc; i++) {
1806                 const char *option = options.git_am_opts.argv[i], *p;
1807                 if (!strcmp(option, "--whitespace=fix") ||
1808                     !strcmp(option, "--whitespace=strip"))
1809                         allow_preemptive_ff = 0;
1810                 else if (skip_prefix(option, "-C", &p)) {
1811                         while (*p)
1812                                 if (!isdigit(*(p++)))
1813                                         die(_("switch `C' expects a "
1814                                               "numerical value"));
1815                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1816                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1817                             strcmp(p, "error") && strcmp(p, "error-all"))
1818                                 die("Invalid whitespace option: '%s'", p);
1819                 }
1820         }
1821
1822         for (i = 0; i < exec.nr; i++)
1823                 if (check_exec_cmd(exec.items[i].string))
1824                         exit(1);
1825
1826         if (!(options.flags & REBASE_NO_QUIET))
1827                 argv_array_push(&options.git_am_opts, "-q");
1828
1829         if (options.empty != EMPTY_UNSPECIFIED)
1830                 imply_merge(&options, "--empty");
1831
1832         if (gpg_sign) {
1833                 free(options.gpg_sign_opt);
1834                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1835         }
1836
1837         if (exec.nr) {
1838                 int i;
1839
1840                 imply_merge(&options, "--exec");
1841
1842                 strbuf_reset(&buf);
1843                 for (i = 0; i < exec.nr; i++)
1844                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1845                 options.cmd = xstrdup(buf.buf);
1846         }
1847
1848         if (rebase_merges) {
1849                 if (!*rebase_merges)
1850                         ; /* default mode; do nothing */
1851                 else if (!strcmp("rebase-cousins", rebase_merges))
1852                         options.rebase_cousins = 1;
1853                 else if (strcmp("no-rebase-cousins", rebase_merges))
1854                         die(_("Unknown mode: %s"), rebase_merges);
1855                 options.rebase_merges = 1;
1856                 imply_merge(&options, "--rebase-merges");
1857         }
1858
1859         if (options.type == REBASE_APPLY) {
1860                 if (ignore_whitespace)
1861                         argv_array_push(&options.git_am_opts,
1862                                         "--ignore-whitespace");
1863                 if (options.committer_date_is_author_date)
1864                         argv_array_push(&options.git_am_opts,
1865                                         "--committer-date-is-author-date");
1866                 if (options.ignore_date)
1867                         argv_array_push(&options.git_am_opts, "--ignore-date");
1868         } else {
1869                 /* REBASE_MERGE and PRESERVE_MERGES */
1870                 if (ignore_whitespace) {
1871                         string_list_append(&strategy_options,
1872                                            "ignore-space-change");
1873                 }
1874         }
1875
1876         if (strategy_options.nr) {
1877                 int i;
1878
1879                 if (!options.strategy)
1880                         options.strategy = "recursive";
1881
1882                 strbuf_reset(&buf);
1883                 for (i = 0; i < strategy_options.nr; i++)
1884                         strbuf_addf(&buf, " --%s",
1885                                     strategy_options.items[i].string);
1886                 options.strategy_opts = xstrdup(buf.buf);
1887         }
1888
1889         if (options.strategy) {
1890                 options.strategy = xstrdup(options.strategy);
1891                 switch (options.type) {
1892                 case REBASE_APPLY:
1893                         die(_("--strategy requires --merge or --interactive"));
1894                 case REBASE_MERGE:
1895                 case REBASE_PRESERVE_MERGES:
1896                         /* compatible */
1897                         break;
1898                 case REBASE_UNSPECIFIED:
1899                         options.type = REBASE_MERGE;
1900                         break;
1901                 default:
1902                         BUG("unhandled rebase type (%d)", options.type);
1903                 }
1904         }
1905
1906         if (options.type == REBASE_MERGE)
1907                 imply_merge(&options, "--merge");
1908
1909         if (options.root && !options.onto_name)
1910                 imply_merge(&options, "--root without --onto");
1911
1912         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1913                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1914
1915         if (options.git_am_opts.argc || options.type == REBASE_APPLY) {
1916                 /* all am options except -q are compatible only with --apply */
1917                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1918                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1919                                 break;
1920
1921                 if (i >= 0) {
1922                         if (is_merge(&options))
1923                                 die(_("cannot combine apply options with "
1924                                       "merge options"));
1925                         else
1926                                 options.type = REBASE_APPLY;
1927                 }
1928         }
1929
1930         if (options.type == REBASE_UNSPECIFIED) {
1931                 if (!strcmp(options.default_backend, "merge"))
1932                         imply_merge(&options, "--merge");
1933                 else if (!strcmp(options.default_backend, "apply"))
1934                         options.type = REBASE_APPLY;
1935                 else
1936                         die(_("Unknown rebase backend: %s"),
1937                             options.default_backend);
1938         }
1939
1940         switch (options.type) {
1941         case REBASE_MERGE:
1942         case REBASE_PRESERVE_MERGES:
1943                 options.state_dir = merge_dir();
1944                 break;
1945         case REBASE_APPLY:
1946                 options.state_dir = apply_dir();
1947                 break;
1948         default:
1949                 BUG("options.type was just set above; should be unreachable.");
1950         }
1951
1952         if (options.empty == EMPTY_UNSPECIFIED) {
1953                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1954                         options.empty = EMPTY_ASK;
1955                 else if (exec.nr > 0)
1956                         options.empty = EMPTY_KEEP;
1957                 else
1958                         options.empty = EMPTY_DROP;
1959         }
1960         if (reschedule_failed_exec > 0 && !is_merge(&options))
1961                 die(_("--reschedule-failed-exec requires "
1962                       "--exec or --interactive"));
1963         if (reschedule_failed_exec >= 0)
1964                 options.reschedule_failed_exec = reschedule_failed_exec;
1965
1966         if (options.signoff) {
1967                 if (options.type == REBASE_PRESERVE_MERGES)
1968                         die("cannot combine '--signoff' with "
1969                             "'--preserve-merges'");
1970                 argv_array_push(&options.git_am_opts, "--signoff");
1971                 options.flags |= REBASE_FORCE;
1972         }
1973
1974         if (options.type == REBASE_PRESERVE_MERGES) {
1975                 /*
1976                  * Note: incompatibility with --signoff handled in signoff block above
1977                  * Note: incompatibility with --interactive is just a strong warning;
1978                  *       git-rebase.txt caveats with "unless you know what you are doing"
1979                  */
1980                 if (options.rebase_merges)
1981                         die(_("cannot combine '--preserve-merges' with "
1982                               "'--rebase-merges'"));
1983
1984                 if (options.reschedule_failed_exec)
1985                         die(_("error: cannot combine '--preserve-merges' with "
1986                               "'--reschedule-failed-exec'"));
1987         }
1988
1989         if (!options.root) {
1990                 if (argc < 1) {
1991                         struct branch *branch;
1992
1993                         branch = branch_get(NULL);
1994                         options.upstream_name = branch_get_upstream(branch,
1995                                                                     NULL);
1996                         if (!options.upstream_name)
1997                                 error_on_missing_default_upstream();
1998                         if (fork_point < 0)
1999                                 fork_point = 1;
2000                 } else {
2001                         options.upstream_name = argv[0];
2002                         argc--;
2003                         argv++;
2004                         if (!strcmp(options.upstream_name, "-"))
2005                                 options.upstream_name = "@{-1}";
2006                 }
2007                 options.upstream = peel_committish(options.upstream_name);
2008                 if (!options.upstream)
2009                         die(_("invalid upstream '%s'"), options.upstream_name);
2010                 options.upstream_arg = options.upstream_name;
2011         } else {
2012                 if (!options.onto_name) {
2013                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
2014                                         &squash_onto, NULL, NULL) < 0)
2015                                 die(_("Could not create new root commit"));
2016                         options.squash_onto = &squash_onto;
2017                         options.onto_name = squash_onto_name =
2018                                 xstrdup(oid_to_hex(&squash_onto));
2019                 } else
2020                         options.root_with_onto = 1;
2021
2022                 options.upstream_name = NULL;
2023                 options.upstream = NULL;
2024                 if (argc > 1)
2025                         usage_with_options(builtin_rebase_usage,
2026                                            builtin_rebase_options);
2027                 options.upstream_arg = "--root";
2028         }
2029
2030         /* Make sure the branch to rebase onto is valid. */
2031         if (keep_base) {
2032                 strbuf_reset(&buf);
2033                 strbuf_addstr(&buf, options.upstream_name);
2034                 strbuf_addstr(&buf, "...");
2035                 options.onto_name = xstrdup(buf.buf);
2036         } else if (!options.onto_name)
2037                 options.onto_name = options.upstream_name;
2038         if (strstr(options.onto_name, "...")) {
2039                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
2040                         if (keep_base)
2041                                 die(_("'%s': need exactly one merge base with branch"),
2042                                     options.upstream_name);
2043                         else
2044                                 die(_("'%s': need exactly one merge base"),
2045                                     options.onto_name);
2046                 }
2047                 options.onto = lookup_commit_or_die(&merge_base,
2048                                                     options.onto_name);
2049         } else {
2050                 options.onto = peel_committish(options.onto_name);
2051                 if (!options.onto)
2052                         die(_("Does not point to a valid commit '%s'"),
2053                                 options.onto_name);
2054         }
2055
2056         /*
2057          * If the branch to rebase is given, that is the branch we will rebase
2058          * branch_name -- branch/commit being rebased, or
2059          *                HEAD (already detached)
2060          * orig_head -- commit object name of tip of the branch before rebasing
2061          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
2062          */
2063         if (argc == 1) {
2064                 /* Is it "rebase other branchname" or "rebase other commit"? */
2065                 branch_name = argv[0];
2066                 options.switch_to = argv[0];
2067
2068                 /* Is it a local branch? */
2069                 strbuf_reset(&buf);
2070                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
2071                 if (!read_ref(buf.buf, &options.orig_head)) {
2072                         die_if_checked_out(buf.buf, 1);
2073                         options.head_name = xstrdup(buf.buf);
2074                 /* If not is it a valid ref (branch or commit)? */
2075                 } else if (!get_oid(branch_name, &options.orig_head))
2076                         options.head_name = NULL;
2077                 else
2078                         die(_("fatal: no such branch/commit '%s'"),
2079                             branch_name);
2080         } else if (argc == 0) {
2081                 /* Do not need to switch branches, we are already on it. */
2082                 options.head_name =
2083                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
2084                                          &flags));
2085                 if (!options.head_name)
2086                         die(_("No such ref: %s"), "HEAD");
2087                 if (flags & REF_ISSYMREF) {
2088                         if (!skip_prefix(options.head_name,
2089                                          "refs/heads/", &branch_name))
2090                                 branch_name = options.head_name;
2091
2092                 } else {
2093                         FREE_AND_NULL(options.head_name);
2094                         branch_name = "HEAD";
2095                 }
2096                 if (get_oid("HEAD", &options.orig_head))
2097                         die(_("Could not resolve HEAD to a revision"));
2098         } else
2099                 BUG("unexpected number of arguments left to parse");
2100
2101         if (fork_point > 0) {
2102                 struct commit *head =
2103                         lookup_commit_reference(the_repository,
2104                                                 &options.orig_head);
2105                 options.restrict_revision =
2106                         get_fork_point(options.upstream_name, head);
2107         }
2108
2109         if (repo_read_index(the_repository) < 0)
2110                 die(_("could not read index"));
2111
2112         if (options.autostash) {
2113                 struct lock_file lock_file = LOCK_INIT;
2114                 int fd;
2115
2116                 fd = hold_locked_index(&lock_file, 0);
2117                 refresh_cache(REFRESH_QUIET);
2118                 if (0 <= fd)
2119                         repo_update_index_if_able(the_repository, &lock_file);
2120                 rollback_lock_file(&lock_file);
2121
2122                 if (has_unstaged_changes(the_repository, 1) ||
2123                     has_uncommitted_changes(the_repository, 1)) {
2124                         const char *autostash =
2125                                 state_dir_path("autostash", &options);
2126                         struct child_process stash = CHILD_PROCESS_INIT;
2127                         struct object_id oid;
2128
2129                         argv_array_pushl(&stash.args,
2130                                          "stash", "create", "autostash", NULL);
2131                         stash.git_cmd = 1;
2132                         stash.no_stdin = 1;
2133                         strbuf_reset(&buf);
2134                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
2135                                 die(_("Cannot autostash"));
2136                         strbuf_trim_trailing_newline(&buf);
2137                         if (get_oid(buf.buf, &oid))
2138                                 die(_("Unexpected stash response: '%s'"),
2139                                     buf.buf);
2140                         strbuf_reset(&buf);
2141                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
2142
2143                         if (safe_create_leading_directories_const(autostash))
2144                                 die(_("Could not create directory for '%s'"),
2145                                     options.state_dir);
2146                         write_file(autostash, "%s", oid_to_hex(&oid));
2147                         printf(_("Created autostash: %s\n"), buf.buf);
2148                         if (reset_head(NULL, "reset --hard",
2149                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2150                                 die(_("could not reset --hard"));
2151
2152                         if (discard_index(the_repository->index) < 0 ||
2153                                 repo_read_index(the_repository) < 0)
2154                                 die(_("could not read index"));
2155                 }
2156         }
2157
2158         if (require_clean_work_tree(the_repository, "rebase",
2159                                     _("Please commit or stash them."), 1, 1)) {
2160                 ret = 1;
2161                 goto cleanup;
2162         }
2163
2164         /*
2165          * Now we are rebasing commits upstream..orig_head (or with --root,
2166          * everything leading up to orig_head) on top of onto.
2167          */
2168
2169         /*
2170          * Check if we are already based on onto with linear history,
2171          * in which case we could fast-forward without replacing the commits
2172          * with new commits recreated by replaying their changes.
2173          *
2174          * Note that can_fast_forward() initializes merge_base, so we have to
2175          * call it before checking allow_preemptive_ff.
2176          */
2177         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
2178                     &options.orig_head, &merge_base) &&
2179             allow_preemptive_ff) {
2180                 int flag;
2181
2182                 if (!(options.flags & REBASE_FORCE)) {
2183                         /* Lazily switch to the target branch if needed... */
2184                         if (options.switch_to) {
2185                                 strbuf_reset(&buf);
2186                                 strbuf_addf(&buf, "%s: checkout %s",
2187                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2188                                             options.switch_to);
2189                                 if (reset_head(&options.orig_head, "checkout",
2190                                                options.head_name,
2191                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2192                                                NULL, buf.buf) < 0) {
2193                                         ret = !!error(_("could not switch to "
2194                                                         "%s"),
2195                                                       options.switch_to);
2196                                         goto cleanup;
2197                                 }
2198                         }
2199
2200                         if (!(options.flags & REBASE_NO_QUIET))
2201                                 ; /* be quiet */
2202                         else if (!strcmp(branch_name, "HEAD") &&
2203                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2204                                 puts(_("HEAD is up to date."));
2205                         else
2206                                 printf(_("Current branch %s is up to date.\n"),
2207                                        branch_name);
2208                         ret = !!finish_rebase(&options);
2209                         goto cleanup;
2210                 } else if (!(options.flags & REBASE_NO_QUIET))
2211                         ; /* be quiet */
2212                 else if (!strcmp(branch_name, "HEAD") &&
2213                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2214                         puts(_("HEAD is up to date, rebase forced."));
2215                 else
2216                         printf(_("Current branch %s is up to date, rebase "
2217                                  "forced.\n"), branch_name);
2218         }
2219
2220         /* If a hook exists, give it a chance to interrupt*/
2221         if (!ok_to_skip_pre_rebase &&
2222             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2223                         argc ? argv[0] : NULL, NULL))
2224                 die(_("The pre-rebase hook refused to rebase."));
2225
2226         if (options.flags & REBASE_DIFFSTAT) {
2227                 struct diff_options opts;
2228
2229                 if (options.flags & REBASE_VERBOSE) {
2230                         if (is_null_oid(&merge_base))
2231                                 printf(_("Changes to %s:\n"),
2232                                        oid_to_hex(&options.onto->object.oid));
2233                         else
2234                                 printf(_("Changes from %s to %s:\n"),
2235                                        oid_to_hex(&merge_base),
2236                                        oid_to_hex(&options.onto->object.oid));
2237                 }
2238
2239                 /* We want color (if set), but no pager */
2240                 diff_setup(&opts);
2241                 opts.stat_width = -1; /* use full terminal width */
2242                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2243                 opts.output_format |=
2244                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2245                 opts.detect_rename = DIFF_DETECT_RENAME;
2246                 diff_setup_done(&opts);
2247                 diff_tree_oid(is_null_oid(&merge_base) ?
2248                               the_hash_algo->empty_tree : &merge_base,
2249                               &options.onto->object.oid, "", &opts);
2250                 diffcore_std(&opts);
2251                 diff_flush(&opts);
2252         }
2253
2254         if (is_merge(&options))
2255                 goto run_rebase;
2256
2257         /* Detach HEAD and reset the tree */
2258         if (options.flags & REBASE_NO_QUIET)
2259                 printf(_("First, rewinding head to replay your work on top of "
2260                          "it...\n"));
2261
2262         strbuf_addf(&msg, "%s: checkout %s",
2263                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2264         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2265                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2266                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2267                        NULL, msg.buf))
2268                 die(_("Could not detach HEAD"));
2269         strbuf_release(&msg);
2270
2271         /*
2272          * If the onto is a proper descendant of the tip of the branch, then
2273          * we just fast-forwarded.
2274          */
2275         strbuf_reset(&msg);
2276         if (oideq(&merge_base, &options.orig_head)) {
2277                 printf(_("Fast-forwarded %s to %s.\n"),
2278                         branch_name, options.onto_name);
2279                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2280                         options.head_name ? options.head_name : "detached HEAD",
2281                         oid_to_hex(&options.onto->object.oid));
2282                 reset_head(NULL, "Fast-forwarded", options.head_name,
2283                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2284                 strbuf_release(&msg);
2285                 ret = !!finish_rebase(&options);
2286                 goto cleanup;
2287         }
2288
2289         strbuf_addf(&revisions, "%s..%s",
2290                     options.root ? oid_to_hex(&options.onto->object.oid) :
2291                     (options.restrict_revision ?
2292                      oid_to_hex(&options.restrict_revision->object.oid) :
2293                      oid_to_hex(&options.upstream->object.oid)),
2294                     oid_to_hex(&options.orig_head));
2295
2296         options.revisions = revisions.buf;
2297
2298 run_rebase:
2299         ret = !!run_specific_rebase(&options, action);
2300
2301 cleanup:
2302         strbuf_release(&buf);
2303         strbuf_release(&revisions);
2304         free(options.head_name);
2305         free(options.gpg_sign_opt);
2306         free(options.cmd);
2307         free(squash_onto_name);
2308         return ret;
2309 }