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         char *cmd;
  92         int allow_empty_message;
  93         int rebase_merges, rebase_cousins;
  94         char *strategy, *strategy_opts;
  95         struct strbuf git_format_patch_opt;
  96         int reschedule_failed_exec;
  97         int use_legacy_rebase;
  98 };
  99
 100 #define REBASE_OPTIONS_INIT {                           \
 101                 .type = REBASE_UNSPECIFIED,             \
 102                 .empty = EMPTY_UNSPECIFIED,             \
 103                 .default_backend = "merge",             \
 104                 .flags = REBASE_NO_QUIET,               \
 105                 .git_am_opts = ARGV_ARRAY_INIT,         \
 106                 .git_format_patch_opt = STRBUF_INIT     \
 107         }
 108
 109 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 110 {
 111         struct replay_opts replay = REPLAY_OPTS_INIT;
 112
 113         replay.action = REPLAY_INTERACTIVE_REBASE;
 114         sequencer_init_config(&replay);
 115
 116         replay.signoff = opts->signoff;
 117         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 118         if (opts->allow_rerere_autoupdate)
 119                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 120         replay.allow_empty = 1;
 121         replay.allow_empty_message = opts->allow_empty_message;
 122         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
 123         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
 124         replay.quiet = !(opts->flags & REBASE_NO_QUIET);
 125         replay.verbose = opts->flags & REBASE_VERBOSE;
 126         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 127         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 128         replay.strategy = opts->strategy;
 129
 130         if (opts->strategy_opts)
 131                 parse_strategy_opts(&replay, opts->strategy_opts);
 132
 133         if (opts->squash_onto) {
 134                 oidcpy(&replay.squash_onto, opts->squash_onto);
 135                 replay.have_squash_onto = 1;
 136         }
 137
 138         return replay;
 139 }
 140
 141 enum action {
 142         ACTION_NONE = 0,
 143         ACTION_CONTINUE,
 144         ACTION_SKIP,
 145         ACTION_ABORT,
 146         ACTION_QUIT,
 147         ACTION_EDIT_TODO,
 148         ACTION_SHOW_CURRENT_PATCH,
 149         ACTION_SHORTEN_OIDS,
 150         ACTION_EXPAND_OIDS,
 151         ACTION_CHECK_TODO_LIST,
 152         ACTION_REARRANGE_SQUASH,
 153         ACTION_ADD_EXEC
 154 };
 155
 156 static const char *action_names[] = { "undefined",
 157                                       "continue",
 158                                       "skip",
 159                                       "abort",
 160                                       "quit",
 161                                       "edit_todo",
 162                                       "show_current_patch" };
 163
 164 static int add_exec_commands(struct string_list *commands)
 165 {
 166         const char *todo_file = rebase_path_todo();
 167         struct todo_list todo_list = TODO_LIST_INIT;
 168         int res;
 169
 170         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 171                 return error_errno(_("could not read '%s'."), todo_file);
 172
 173         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 174                                         &todo_list)) {
 175                 todo_list_release(&todo_list);
 176                 return error(_("unusable todo list: '%s'"), todo_file);
 177         }
 178
 179         todo_list_add_exec_commands(&todo_list, commands);
 180         res = todo_list_write_to_file(the_repository, &todo_list,
 181                                       todo_file, NULL, NULL, -1, 0);
 182         todo_list_release(&todo_list);
 183
 184         if (res)
 185                 return error_errno(_("could not write '%s'."), todo_file);
 186         return 0;
 187 }
 188
 189 static int rearrange_squash_in_todo_file(void)
 190 {
 191         const char *todo_file = rebase_path_todo();
 192         struct todo_list todo_list = TODO_LIST_INIT;
 193         int res = 0;
 194
 195         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 196                 return error_errno(_("could not read '%s'."), todo_file);
 197         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 198                                         &todo_list)) {
 199                 todo_list_release(&todo_list);
 200                 return error(_("unusable todo list: '%s'"), todo_file);
 201         }
 202
 203         res = todo_list_rearrange_squash(&todo_list);
 204         if (!res)
 205                 res = todo_list_write_to_file(the_repository, &todo_list,
 206                                               todo_file, NULL, NULL, -1, 0);
 207
 208         todo_list_release(&todo_list);
 209
 210         if (res)
 211                 return error_errno(_("could not write '%s'."), todo_file);
 212         return 0;
 213 }
 214
 215 static int transform_todo_file(unsigned flags)
 216 {
 217         const char *todo_file = rebase_path_todo();
 218         struct todo_list todo_list = TODO_LIST_INIT;
 219         int res;
 220
 221         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 222                 return error_errno(_("could not read '%s'."), todo_file);
 223
 224         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 225                                         &todo_list)) {
 226                 todo_list_release(&todo_list);
 227                 return error(_("unusable todo list: '%s'"), todo_file);
 228         }
 229
 230         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 231                                       NULL, NULL, -1, flags);
 232         todo_list_release(&todo_list);
 233
 234         if (res)
 235                 return error_errno(_("could not write '%s'."), todo_file);
 236         return 0;
 237 }
 238
 239 static int edit_todo_file(unsigned flags)
 240 {
 241         const char *todo_file = rebase_path_todo();
 242         struct todo_list todo_list = TODO_LIST_INIT,
 243                 new_todo = TODO_LIST_INIT;
 244         int res = 0;
 245
 246         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 247                 return error_errno(_("could not read '%s'."), todo_file);
 248
 249         strbuf_stripspace(&todo_list.buf, 1);
 250         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 251         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 252                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 253                 res = error_errno(_("could not write '%s'"), todo_file);
 254
 255         todo_list_release(&todo_list);
 256         todo_list_release(&new_todo);
 257
 258         return res;
 259 }
 260
 261 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 262                                struct object_id *orig_head, const char **head_hash,
 263                                char **revisions, char **shortrevisions)
 264 {
 265         struct commit *base_rev = upstream ? upstream : onto;
 266         const char *shorthead;
 267
 268         *head_hash = find_unique_abbrev(orig_head, GIT_MAX_HEXSZ);
 269         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 270                                                    *head_hash);
 271
 272         shorthead = find_unique_abbrev(orig_head, DEFAULT_ABBREV);
 273
 274         if (upstream) {
 275                 const char *shortrev;
 276
 277                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 278                                               DEFAULT_ABBREV);
 279
 280                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 281         } else
 282                 *shortrevisions = xstrdup(shorthead);
 283
 284         return 0;
 285 }
 286
 287 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 288                             struct commit *onto, const char *orig_head)
 289 {
 290         FILE *interactive;
 291
 292         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 293                 return error_errno(_("could not create temporary %s"), merge_dir());
 294
 295         delete_reflog("REBASE_HEAD");
 296
 297         interactive = fopen(path_interactive(), "w");
 298         if (!interactive)
 299                 return error_errno(_("could not mark as interactive"));
 300         fclose(interactive);
 301
 302         return write_basic_state(opts, head_name, onto, orig_head);
 303 }
 304
 305 static void split_exec_commands(const char *cmd, struct string_list *commands)
 306 {
 307         if (cmd && *cmd) {
 308                 string_list_split(commands, cmd, '\n', -1);
 309
 310                 /* rebase.c adds a new line to cmd after every command,
 311                  * so here the last command is always empty */
 312                 string_list_remove_empty_items(commands, 0);
 313         }
 314 }
 315
 316 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 317 {
 318         int ret;
 319         const char *head_hash = NULL;
 320         char *revisions = NULL, *shortrevisions = NULL;
 321         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 322         struct todo_list todo_list = TODO_LIST_INIT;
 323         struct replay_opts replay = get_replay_opts(opts);
 324         struct string_list commands = STRING_LIST_INIT_DUP;
 325
 326         if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head,
 327                                 &head_hash, &revisions, &shortrevisions))
 328                 return -1;
 329
 330         if (init_basic_state(&replay,
 331                              opts->head_name ? opts->head_name : "detached HEAD",
 332                              opts->onto, head_hash)) {
 333                 free(revisions);
 334                 free(shortrevisions);
 335
 336                 return -1;
 337         }
 338
 339         if (!opts->upstream && opts->squash_onto)
 340                 write_file(path_squash_onto(), "%s\n",
 341                            oid_to_hex(opts->squash_onto));
 342
 343         argv_array_pushl(&make_script_args, "", revisions, NULL);
 344         if (opts->restrict_revision)
 345                 argv_array_pushf(&make_script_args, "^%s",
 346                                  oid_to_hex(&opts->restrict_revision->object.oid));
 347
 348         ret = sequencer_make_script(the_repository, &todo_list.buf,
 349                                     make_script_args.argc, make_script_args.argv,
 350                                     flags);
 351
 352         if (ret)
 353                 error(_("could not generate todo list"));
 354         else {
 355                 discard_cache();
 356                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 357                                                 &todo_list))
 358                         BUG("unusable todo list");
 359
 360                 split_exec_commands(opts->cmd, &commands);
 361                 ret = complete_action(the_repository, &replay, flags,
 362                         shortrevisions, opts->onto_name, opts->onto, head_hash,
 363                         &commands, opts->autosquash, &todo_list);
 364         }
 365
 366         string_list_clear(&commands, 0);
 367         free(revisions);
 368         free(shortrevisions);
 369         todo_list_release(&todo_list);
 370         argv_array_clear(&make_script_args);
 371
 372         return ret;
 373 }
 374
 375 static int run_sequencer_rebase(struct rebase_options *opts,
 376                                   enum action command)
 377 {
 378         unsigned flags = 0;
 379         int abbreviate_commands = 0, ret = 0;
 380
 381         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 382
 383         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 384         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 385         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 386         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 387         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 388
 389         switch (command) {
 390         case ACTION_NONE: {
 391                 if (!opts->onto && !opts->upstream)
 392                         die(_("a base commit must be provided with --upstream or --onto"));
 393
 394                 ret = do_interactive_rebase(opts, flags);
 395                 break;
 396         }
 397         case ACTION_SKIP: {
 398                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 399
 400                 rerere_clear(the_repository, &merge_rr);
 401         }
 402                 /* fallthrough */
 403         case ACTION_CONTINUE: {
 404                 struct replay_opts replay_opts = get_replay_opts(opts);
 405
 406                 ret = sequencer_continue(the_repository, &replay_opts);
 407                 break;
 408         }
 409         case ACTION_EDIT_TODO:
 410                 ret = edit_todo_file(flags);
 411                 break;
 412         case ACTION_SHOW_CURRENT_PATCH: {
 413                 struct child_process cmd = CHILD_PROCESS_INIT;
 414
 415                 cmd.git_cmd = 1;
 416                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 417                 ret = run_command(&cmd);
 418
 419                 break;
 420         }
 421         case ACTION_SHORTEN_OIDS:
 422         case ACTION_EXPAND_OIDS:
 423                 ret = transform_todo_file(flags);
 424                 break;
 425         case ACTION_CHECK_TODO_LIST:
 426                 ret = check_todo_list_from_file(the_repository);
 427                 break;
 428         case ACTION_REARRANGE_SQUASH:
 429                 ret = rearrange_squash_in_todo_file();
 430                 break;
 431         case ACTION_ADD_EXEC: {
 432                 struct string_list commands = STRING_LIST_INIT_DUP;
 433
 434                 split_exec_commands(opts->cmd, &commands);
 435                 ret = add_exec_commands(&commands);
 436                 string_list_clear(&commands, 0);
 437                 break;
 438         }
 439         default:
 440                 BUG("invalid command '%d'", command);
 441         }
 442
 443         return ret;
 444 }
 445
 446 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 447                                 int unset)
 448 {
 449         struct rebase_options *opts = opt->value;
 450
 451         BUG_ON_OPT_ARG(arg);
 452
 453         /*
 454          * If we ever want to remap --keep-empty to --empty=keep, insert:
 455          *      opts->empty = unset ? EMPTY_UNSPECIFIED : EMPTY_KEEP;
 456          */
 457         opts->type = REBASE_MERGE;
 458         return 0;
 459 }
 460
 461 static const char * const builtin_rebase_interactive_usage[] = {
 462         N_("git rebase--interactive [<options>]"),
 463         NULL
 464 };
 465
 466 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 467 {
 468         struct rebase_options opts = REBASE_OPTIONS_INIT;
 469         struct object_id squash_onto = null_oid;
 470         enum action command = ACTION_NONE;
 471         struct option options[] = {
 472                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 473                            REBASE_FORCE),
 474                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
 475                         N_("(DEPRECATED) keep empty commits"),
 476                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
 477                         parse_opt_keep_empty },
 478                 OPT_BOOL_F(0, "allow-empty-message", &opts.allow_empty_message,
 479                            N_("allow commits with empty messages"),
 480                            PARSE_OPT_HIDDEN),
 481                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 482                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 483                          N_("keep original branch points of cousins")),
 484                 OPT_BOOL(0, "autosquash", &opts.autosquash,
 485                          N_("move commits that begin with squash!/fixup!")),
 486                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 487                 OPT_BIT('v', "verbose", &opts.flags,
 488                         N_("display a diffstat of what changed upstream"),
 489                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 490                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 491                             ACTION_CONTINUE),
 492                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 493                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 494                             ACTION_EDIT_TODO),
 495                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 496                             ACTION_SHOW_CURRENT_PATCH),
 497                 OPT_CMDMODE(0, "shorten-ids", &command,
 498                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 499                 OPT_CMDMODE(0, "expand-ids", &command,
 500                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 501                 OPT_CMDMODE(0, "check-todo-list", &command,
 502                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 503                 OPT_CMDMODE(0, "rearrange-squash", &command,
 504                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 505                 OPT_CMDMODE(0, "add-exec-commands", &command,
 506                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 507                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 508                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 509                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 510                   N_("restrict-revision"), N_("restrict revision"),
 511                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 512                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 513                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 514                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 515                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 516                   0 },
 517                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 518                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 519                         N_("GPG-sign commits"),
 520                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 521                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 522                            N_("rebase strategy")),
 523                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 524                            N_("strategy options")),
 525                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 526                            N_("the branch or commit to checkout")),
 527                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 528                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 529                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 530                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 531                          N_("automatically re-schedule any `exec` that fails")),
 532                 OPT_END()
 533         };
 534
 535         opts.rebase_cousins = -1;
 536
 537         if (argc == 1)
 538                 usage_with_options(builtin_rebase_interactive_usage, options);
 539
 540         argc = parse_options(argc, argv, prefix, options,
 541                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 542
 543         if (!is_null_oid(&squash_onto))
 544                 opts.squash_onto = &squash_onto;
 545
 546         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 547                 warning(_("--[no-]rebase-cousins has no effect without "
 548                           "--rebase-merges"));
 549
 550         return !!run_sequencer_rebase(&opts, command);
 551 }
 552
 553 static int is_merge(struct rebase_options *opts)
 554 {
 555         return opts->type == REBASE_MERGE ||
 556                 opts->type == REBASE_PRESERVE_MERGES;
 557 }
 558
 559 static void imply_merge(struct rebase_options *opts, const char *option)
 560 {
 561         switch (opts->type) {
 562         case REBASE_APPLY:
 563                 die(_("%s requires an interactive rebase"), option);
 564                 break;
 565         case REBASE_MERGE:
 566         case REBASE_PRESERVE_MERGES:
 567                 break;
 568         default:
 569                 opts->type = REBASE_MERGE; /* implied */
 570                 break;
 571         }
 572 }
 573
 574 /* Returns the filename prefixed by the state_dir */
 575 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 576 {
 577         static struct strbuf path = STRBUF_INIT;
 578         static size_t prefix_len;
 579
 580         if (!prefix_len) {
 581                 strbuf_addf(&path, "%s/", opts->state_dir);
 582                 prefix_len = path.len;
 583         }
 584
 585         strbuf_setlen(&path, prefix_len);
 586         strbuf_addstr(&path, filename);
 587         return path.buf;
 588 }
 589
 590 /* Read one file, then strip line endings */
 591 static int read_one(const char *path, struct strbuf *buf)
 592 {
 593         if (strbuf_read_file(buf, path, 0) < 0)
 594                 return error_errno(_("could not read '%s'"), path);
 595         strbuf_trim_trailing_newline(buf);
 596         return 0;
 597 }
 598
 599 /* Initialize the rebase options from the state directory. */
 600 static int read_basic_state(struct rebase_options *opts)
 601 {
 602         struct strbuf head_name = STRBUF_INIT;
 603         struct strbuf buf = STRBUF_INIT;
 604         struct object_id oid;
 605
 606         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 607             read_one(state_dir_path("onto", opts), &buf))
 608                 return -1;
 609         opts->head_name = starts_with(head_name.buf, "refs/") ?
 610                 xstrdup(head_name.buf) : NULL;
 611         strbuf_release(&head_name);
 612         if (get_oid(buf.buf, &oid))
 613                 return error(_("could not get 'onto': '%s'"), buf.buf);
 614         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 615
 616         /*
 617          * We always write to orig-head, but interactive rebase used to write to
 618          * head. Fall back to reading from head to cover for the case that the
 619          * user upgraded git with an ongoing interactive rebase.
 620          */
 621         strbuf_reset(&buf);
 622         if (file_exists(state_dir_path("orig-head", opts))) {
 623                 if (read_one(state_dir_path("orig-head", opts), &buf))
 624                         return -1;
 625         } else if (read_one(state_dir_path("head", opts), &buf))
 626                 return -1;
 627         if (get_oid(buf.buf, &opts->orig_head))
 628                 return error(_("invalid orig-head: '%s'"), buf.buf);
 629
 630         if (file_exists(state_dir_path("quiet", opts)))
 631                 opts->flags &= ~REBASE_NO_QUIET;
 632         else
 633                 opts->flags |= REBASE_NO_QUIET;
 634
 635         if (file_exists(state_dir_path("verbose", opts)))
 636                 opts->flags |= REBASE_VERBOSE;
 637
 638         if (file_exists(state_dir_path("signoff", opts))) {
 639                 opts->signoff = 1;
 640                 opts->flags |= REBASE_FORCE;
 641         }
 642
 643         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 644                 strbuf_reset(&buf);
 645                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 646                             &buf))
 647                         return -1;
 648                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 649                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 650                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 651                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 652                 else
 653                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 654                                   "'%s'"), buf.buf);
 655         }
 656
 657         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 658                 strbuf_reset(&buf);
 659                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 660                             &buf))
 661                         return -1;
 662                 free(opts->gpg_sign_opt);
 663                 opts->gpg_sign_opt = xstrdup(buf.buf);
 664         }
 665
 666         if (file_exists(state_dir_path("strategy", opts))) {
 667                 strbuf_reset(&buf);
 668                 if (read_one(state_dir_path("strategy", opts), &buf))
 669                         return -1;
 670                 free(opts->strategy);
 671                 opts->strategy = xstrdup(buf.buf);
 672         }
 673
 674         if (file_exists(state_dir_path("strategy_opts", opts))) {
 675                 strbuf_reset(&buf);
 676                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 677                         return -1;
 678                 free(opts->strategy_opts);
 679                 opts->strategy_opts = xstrdup(buf.buf);
 680         }
 681
 682         strbuf_release(&buf);
 683
 684         return 0;
 685 }
 686
 687 static int rebase_write_basic_state(struct rebase_options *opts)
 688 {
 689         write_file(state_dir_path("head-name", opts), "%s",
 690                    opts->head_name ? opts->head_name : "detached HEAD");
 691         write_file(state_dir_path("onto", opts), "%s",
 692                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 693         write_file(state_dir_path("orig-head", opts), "%s",
 694                    oid_to_hex(&opts->orig_head));
 695         if (!(opts->flags & REBASE_NO_QUIET))
 696                 write_file(state_dir_path("quiet", opts), "%s", "");
 697         if (opts->flags & REBASE_VERBOSE)
 698                 write_file(state_dir_path("verbose", opts), "%s", "");
 699         if (opts->strategy)
 700                 write_file(state_dir_path("strategy", opts), "%s",
 701                            opts->strategy);
 702         if (opts->strategy_opts)
 703                 write_file(state_dir_path("strategy_opts", opts), "%s",
 704                            opts->strategy_opts);
 705         if (opts->allow_rerere_autoupdate > 0)
 706                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 707                            "-%s-rerere-autoupdate",
 708                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 709                                 "" : "-no");
 710         if (opts->gpg_sign_opt)
 711                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 712                            opts->gpg_sign_opt);
 713         if (opts->signoff)
 714                 write_file(state_dir_path("signoff", opts), "--signoff");
 715
 716         return 0;
 717 }
 718
 719 static int apply_autostash(struct rebase_options *opts)
 720 {
 721         const char *path = state_dir_path("autostash", opts);
 722         struct strbuf autostash = STRBUF_INIT;
 723         struct child_process stash_apply = CHILD_PROCESS_INIT;
 724
 725         if (!file_exists(path))
 726                 return 0;
 727
 728         if (read_one(path, &autostash))
 729                 return error(_("Could not read '%s'"), path);
 730         /* Ensure that the hash is not mistaken for a number */
 731         strbuf_addstr(&autostash, "^0");
 732         argv_array_pushl(&stash_apply.args,
 733                          "stash", "apply", autostash.buf, NULL);
 734         stash_apply.git_cmd = 1;
 735         stash_apply.no_stderr = stash_apply.no_stdout =
 736                 stash_apply.no_stdin = 1;
 737         if (!run_command(&stash_apply))
 738                 printf(_("Applied autostash.\n"));
 739         else {
 740                 struct argv_array args = ARGV_ARRAY_INIT;
 741                 int res = 0;
 742
 743                 argv_array_pushl(&args,
 744                                  "stash", "store", "-m", "autostash", "-q",
 745                                  autostash.buf, NULL);
 746                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 747                         res = error(_("Cannot store %s"), autostash.buf);
 748                 argv_array_clear(&args);
 749                 strbuf_release(&autostash);
 750                 if (res)
 751                         return res;
 752
 753                 fprintf(stderr,
 754                         _("Applying autostash resulted in conflicts.\n"
 755                           "Your changes are safe in the stash.\n"
 756                           "You can run \"git stash pop\" or \"git stash drop\" "
 757                           "at any time.\n"));
 758         }
 759
 760         strbuf_release(&autostash);
 761         return 0;
 762 }
 763
 764 static int finish_rebase(struct rebase_options *opts)
 765 {
 766         struct strbuf dir = STRBUF_INIT;
 767         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 768         int ret = 0;
 769
 770         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 771         apply_autostash(opts);
 772         close_object_store(the_repository->objects);
 773         /*
 774          * We ignore errors in 'gc --auto', since the
 775          * user should see them.
 776          */
 777         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 778         if (opts->type == REBASE_MERGE) {
 779                 struct replay_opts replay = REPLAY_OPTS_INIT;
 780
 781                 replay.action = REPLAY_INTERACTIVE_REBASE;
 782                 ret = sequencer_remove_state(&replay);
 783         } else {
 784                 strbuf_addstr(&dir, opts->state_dir);
 785                 if (remove_dir_recursively(&dir, 0))
 786                         ret = error(_("could not remove '%s'"),
 787                                     opts->state_dir);
 788                 strbuf_release(&dir);
 789         }
 790
 791         return ret;
 792 }
 793
 794 static struct commit *peel_committish(const char *name)
 795 {
 796         struct object *obj;
 797         struct object_id oid;
 798
 799         if (get_oid(name, &oid))
 800                 return NULL;
 801         obj = parse_object(the_repository, &oid);
 802         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 803 }
 804
 805 static void add_var(struct strbuf *buf, const char *name, const char *value)
 806 {
 807         if (!value)
 808                 strbuf_addf(buf, "unset %s; ", name);
 809         else {
 810                 strbuf_addf(buf, "%s=", name);
 811                 sq_quote_buf(buf, value);
 812                 strbuf_addstr(buf, "; ");
 813         }
 814 }
 815
 816 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 817
 818 #define RESET_HEAD_DETACH (1<<0)
 819 #define RESET_HEAD_HARD (1<<1)
 820 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 821 #define RESET_HEAD_REFS_ONLY (1<<3)
 822 #define RESET_ORIG_HEAD (1<<4)
 823
 824 static int reset_head(struct object_id *oid, const char *action,
 825                       const char *switch_to_branch, unsigned flags,
 826                       const char *reflog_orig_head, const char *reflog_head)
 827 {
 828         unsigned detach_head = flags & RESET_HEAD_DETACH;
 829         unsigned reset_hard = flags & RESET_HEAD_HARD;
 830         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 831         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 832         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 833         struct object_id head_oid;
 834         struct tree_desc desc[2] = { { NULL }, { NULL } };
 835         struct lock_file lock = LOCK_INIT;
 836         struct unpack_trees_options unpack_tree_opts;
 837         struct tree *tree;
 838         const char *reflog_action;
 839         struct strbuf msg = STRBUF_INIT;
 840         size_t prefix_len;
 841         struct object_id *orig = NULL, oid_orig,
 842                 *old_orig = NULL, oid_old_orig;
 843         int ret = 0, nr = 0;
 844
 845         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 846                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 847
 848         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 849                 ret = -1;
 850                 goto leave_reset_head;
 851         }
 852
 853         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 854                 ret = error(_("could not determine HEAD revision"));
 855                 goto leave_reset_head;
 856         }
 857
 858         if (!oid)
 859                 oid = &head_oid;
 860
 861         if (refs_only)
 862                 goto reset_head_refs;
 863
 864         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 865         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 866         unpack_tree_opts.head_idx = 1;
 867         unpack_tree_opts.src_index = the_repository->index;
 868         unpack_tree_opts.dst_index = the_repository->index;
 869         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 870         unpack_tree_opts.update = 1;
 871         unpack_tree_opts.merge = 1;
 872         init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
 873         if (!detach_head)
 874                 unpack_tree_opts.reset = 1;
 875
 876         if (repo_read_index_unmerged(the_repository) < 0) {
 877                 ret = error(_("could not read index"));
 878                 goto leave_reset_head;
 879         }
 880
 881         if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 882                 ret = error(_("failed to find tree of %s"),
 883                             oid_to_hex(&head_oid));
 884                 goto leave_reset_head;
 885         }
 886
 887         if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 888                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 889                 goto leave_reset_head;
 890         }
 891
 892         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 893                 ret = -1;
 894                 goto leave_reset_head;
 895         }
 896
 897         tree = parse_tree_indirect(oid);
 898         prime_cache_tree(the_repository, the_repository->index, tree);
 899
 900         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 901                 ret = error(_("could not write index"));
 902                 goto leave_reset_head;
 903         }
 904
 905 reset_head_refs:
 906         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 907         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 908         prefix_len = msg.len;
 909
 910         if (update_orig_head) {
 911                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 912                         old_orig = &oid_old_orig;
 913                 if (!get_oid("HEAD", &oid_orig)) {
 914                         orig = &oid_orig;
 915                         if (!reflog_orig_head) {
 916                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 917                                 reflog_orig_head = msg.buf;
 918                         }
 919                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 920                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 921                 } else if (old_orig)
 922                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 923         }
 924
 925         if (!reflog_head) {
 926                 strbuf_setlen(&msg, prefix_len);
 927                 strbuf_addstr(&msg, "updating HEAD");
 928                 reflog_head = msg.buf;
 929         }
 930         if (!switch_to_branch)
 931                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 932                                  detach_head ? REF_NO_DEREF : 0,
 933                                  UPDATE_REFS_MSG_ON_ERR);
 934         else {
 935                 ret = update_ref(reflog_head, switch_to_branch, oid,
 936                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 937                 if (!ret)
 938                         ret = create_symref("HEAD", switch_to_branch,
 939                                             reflog_head);
 940         }
 941         if (run_hook)
 942                 run_hook_le(NULL, "post-checkout",
 943                             oid_to_hex(orig ? orig : &null_oid),
 944                             oid_to_hex(oid), "1", NULL);
 945
 946 leave_reset_head:
 947         strbuf_release(&msg);
 948         rollback_lock_file(&lock);
 949         while (nr)
 950                 free((void *)desc[--nr].buffer);
 951         return ret;
 952 }
 953
 954 static int move_to_original_branch(struct rebase_options *opts)
 955 {
 956         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 957         int ret;
 958
 959         if (!opts->head_name)
 960                 return 0; /* nothing to move back to */
 961
 962         if (!opts->onto)
 963                 BUG("move_to_original_branch without onto");
 964
 965         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 966                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 967         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 968                     opts->head_name);
 969         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 970                          orig_head_reflog.buf, head_reflog.buf);
 971
 972         strbuf_release(&orig_head_reflog);
 973         strbuf_release(&head_reflog);
 974         return ret;
 975 }
 976
 977 static const char *resolvemsg =
 978 N_("Resolve all conflicts manually, mark them as resolved with\n"
 979 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 980 "You can instead skip this commit: run \"git rebase --skip\".\n"
 981 "To abort and get back to the state before \"git rebase\", run "
 982 "\"git rebase --abort\".");
 983
 984 static int run_am(struct rebase_options *opts)
 985 {
 986         struct child_process am = CHILD_PROCESS_INIT;
 987         struct child_process format_patch = CHILD_PROCESS_INIT;
 988         struct strbuf revisions = STRBUF_INIT;
 989         int status;
 990         char *rebased_patches;
 991
 992         am.git_cmd = 1;
 993         argv_array_push(&am.args, "am");
 994
 995         if (opts->action && !strcmp("continue", opts->action)) {
 996                 argv_array_push(&am.args, "--resolved");
 997                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 998                 if (opts->gpg_sign_opt)
 999                         argv_array_push(&am.args, opts->gpg_sign_opt);
1000                 status = run_command(&am);
1001                 if (status)
1002                         return status;
1003
1004                 return move_to_original_branch(opts);
1005         }
1006         if (opts->action && !strcmp("skip", opts->action)) {
1007                 argv_array_push(&am.args, "--skip");
1008                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1009                 status = run_command(&am);
1010                 if (status)
1011                         return status;
1012
1013                 return move_to_original_branch(opts);
1014         }
1015         if (opts->action && !strcmp("show-current-patch", opts->action)) {
1016                 argv_array_push(&am.args, "--show-current-patch");
1017                 return run_command(&am);
1018         }
1019
1020         strbuf_addf(&revisions, "%s...%s",
1021                     oid_to_hex(opts->root ?
1022                                /* this is now equivalent to !opts->upstream */
1023                                &opts->onto->object.oid :
1024                                &opts->upstream->object.oid),
1025                     oid_to_hex(&opts->orig_head));
1026
1027         rebased_patches = xstrdup(git_path("rebased-patches"));
1028         format_patch.out = open(rebased_patches,
1029                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1030         if (format_patch.out < 0) {
1031                 status = error_errno(_("could not open '%s' for writing"),
1032                                      rebased_patches);
1033                 free(rebased_patches);
1034                 argv_array_clear(&am.args);
1035                 return status;
1036         }
1037
1038         format_patch.git_cmd = 1;
1039         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1040                          "--full-index", "--cherry-pick", "--right-only",
1041                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1042                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
1043                          "--no-base", NULL);
1044         if (opts->git_format_patch_opt.len)
1045                 argv_array_split(&format_patch.args,
1046                                  opts->git_format_patch_opt.buf);
1047         argv_array_push(&format_patch.args, revisions.buf);
1048         if (opts->restrict_revision)
1049                 argv_array_pushf(&format_patch.args, "^%s",
1050                                  oid_to_hex(&opts->restrict_revision->object.oid));
1051
1052         status = run_command(&format_patch);
1053         if (status) {
1054                 unlink(rebased_patches);
1055                 free(rebased_patches);
1056                 argv_array_clear(&am.args);
1057
1058                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1059                            "HEAD", NULL);
1060                 error(_("\ngit encountered an error while preparing the "
1061                         "patches to replay\n"
1062                         "these revisions:\n"
1063                         "\n    %s\n\n"
1064                         "As a result, git cannot rebase them."),
1065                       opts->revisions);
1066
1067                 strbuf_release(&revisions);
1068                 return status;
1069         }
1070         strbuf_release(&revisions);
1071
1072         am.in = open(rebased_patches, O_RDONLY);
1073         if (am.in < 0) {
1074                 status = error_errno(_("could not open '%s' for reading"),
1075                                      rebased_patches);
1076                 free(rebased_patches);
1077                 argv_array_clear(&am.args);
1078                 return status;
1079         }
1080
1081         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1082         argv_array_push(&am.args, "--rebasing");
1083         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1084         argv_array_push(&am.args, "--patch-format=mboxrd");
1085         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1086                 argv_array_push(&am.args, "--rerere-autoupdate");
1087         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1088                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1089         if (opts->gpg_sign_opt)
1090                 argv_array_push(&am.args, opts->gpg_sign_opt);
1091         status = run_command(&am);
1092         unlink(rebased_patches);
1093         free(rebased_patches);
1094
1095         if (!status) {
1096                 return move_to_original_branch(opts);
1097         }
1098
1099         if (is_directory(opts->state_dir))
1100                 rebase_write_basic_state(opts);
1101
1102         return status;
1103 }
1104
1105 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1106 {
1107         const char *argv[] = { NULL, NULL };
1108         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1109         int status;
1110         const char *backend, *backend_func;
1111
1112         if (opts->type == REBASE_MERGE) {
1113                 /* Run sequencer-based rebase */
1114                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1115                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1116                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1117                         opts->autosquash = 0;
1118                 }
1119                 if (opts->gpg_sign_opt) {
1120                         /* remove the leading "-S" */
1121                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1122                         free(opts->gpg_sign_opt);
1123                         opts->gpg_sign_opt = tmp;
1124                 }
1125
1126                 status = run_sequencer_rebase(opts, action);
1127                 goto finished_rebase;
1128         }
1129
1130         if (opts->type == REBASE_APPLY) {
1131                 status = run_am(opts);
1132                 goto finished_rebase;
1133         }
1134
1135         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1136         add_var(&script_snippet, "state_dir", opts->state_dir);
1137
1138         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1139         add_var(&script_snippet, "upstream", opts->upstream ?
1140                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1141         add_var(&script_snippet, "head_name",
1142                 opts->head_name ? opts->head_name : "detached HEAD");
1143         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1144         add_var(&script_snippet, "onto", opts->onto ?
1145                 oid_to_hex(&opts->onto->object.oid) : NULL);
1146         add_var(&script_snippet, "onto_name", opts->onto_name);
1147         add_var(&script_snippet, "revisions", opts->revisions);
1148         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1149                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1150         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1151         add_var(&script_snippet, "git_am_opt", buf.buf);
1152         strbuf_release(&buf);
1153         add_var(&script_snippet, "verbose",
1154                 opts->flags & REBASE_VERBOSE ? "t" : "");
1155         add_var(&script_snippet, "diffstat",
1156                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1157         add_var(&script_snippet, "force_rebase",
1158                 opts->flags & REBASE_FORCE ? "t" : "");
1159         if (opts->switch_to)
1160                 add_var(&script_snippet, "switch_to", opts->switch_to);
1161         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1162         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1163         add_var(&script_snippet, "allow_rerere_autoupdate",
1164                 opts->allow_rerere_autoupdate ?
1165                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1166                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1167         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1168         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1169         add_var(&script_snippet, "cmd", opts->cmd);
1170         add_var(&script_snippet, "allow_empty_message",
1171                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1172         add_var(&script_snippet, "rebase_merges",
1173                 opts->rebase_merges ? "t" : "");
1174         add_var(&script_snippet, "rebase_cousins",
1175                 opts->rebase_cousins ? "t" : "");
1176         add_var(&script_snippet, "strategy", opts->strategy);
1177         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1178         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1179         add_var(&script_snippet, "squash_onto",
1180                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1181         add_var(&script_snippet, "git_format_patch_opt",
1182                 opts->git_format_patch_opt.buf);
1183
1184         if (is_merge(opts) &&
1185             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1186                 strbuf_addstr(&script_snippet,
1187                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1188                 opts->autosquash = 0;
1189         }
1190
1191         switch (opts->type) {
1192         case REBASE_PRESERVE_MERGES:
1193                 backend = "git-rebase--preserve-merges";
1194                 backend_func = "git_rebase__preserve_merges";
1195                 break;
1196         default:
1197                 BUG("Unhandled rebase type %d", opts->type);
1198                 break;
1199         }
1200
1201         strbuf_addf(&script_snippet,
1202                     ". git-sh-setup && . %s && %s", backend, backend_func);
1203         argv[0] = script_snippet.buf;
1204
1205         status = run_command_v_opt(argv, RUN_USING_SHELL);
1206 finished_rebase:
1207         if (opts->dont_finish_rebase)
1208                 ; /* do nothing */
1209         else if (opts->type == REBASE_MERGE)
1210                 ; /* merge backend cleans up after itself */
1211         else if (status == 0) {
1212                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1213                         finish_rebase(opts);
1214         } else if (status == 2) {
1215                 struct strbuf dir = STRBUF_INIT;
1216
1217                 apply_autostash(opts);
1218                 strbuf_addstr(&dir, opts->state_dir);
1219                 remove_dir_recursively(&dir, 0);
1220                 strbuf_release(&dir);
1221                 die("Nothing to do");
1222         }
1223
1224         strbuf_release(&script_snippet);
1225
1226         return status ? -1 : 0;
1227 }
1228
1229 static int rebase_config(const char *var, const char *value, void *data)
1230 {
1231         struct rebase_options *opts = data;
1232
1233         if (!strcmp(var, "rebase.stat")) {
1234                 if (git_config_bool(var, value))
1235                         opts->flags |= REBASE_DIFFSTAT;
1236                 else
1237                         opts->flags &= ~REBASE_DIFFSTAT;
1238                 return 0;
1239         }
1240
1241         if (!strcmp(var, "rebase.autosquash")) {
1242                 opts->autosquash = git_config_bool(var, value);
1243                 return 0;
1244         }
1245
1246         if (!strcmp(var, "commit.gpgsign")) {
1247                 free(opts->gpg_sign_opt);
1248                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1249                         xstrdup("-S") : NULL;
1250                 return 0;
1251         }
1252
1253         if (!strcmp(var, "rebase.autostash")) {
1254                 opts->autostash = git_config_bool(var, value);
1255                 return 0;
1256         }
1257
1258         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1259                 opts->reschedule_failed_exec = git_config_bool(var, value);
1260                 return 0;
1261         }
1262
1263         if (!strcmp(var, "rebase.usebuiltin")) {
1264                 opts->use_legacy_rebase = !git_config_bool(var, value);
1265                 return 0;
1266         }
1267
1268         if (!strcmp(var, "rebase.backend")) {
1269                 return git_config_string(&opts->default_backend, var, value);
1270         }
1271
1272         return git_default_config(var, value, data);
1273 }
1274
1275 /*
1276  * Determines whether the commits in from..to are linear, i.e. contain
1277  * no merge commits. This function *expects* `from` to be an ancestor of
1278  * `to`.
1279  */
1280 static int is_linear_history(struct commit *from, struct commit *to)
1281 {
1282         while (to && to != from) {
1283                 parse_commit(to);
1284                 if (!to->parents)
1285                         return 1;
1286                 if (to->parents->next)
1287                         return 0;
1288                 to = to->parents->item;
1289         }
1290         return 1;
1291 }
1292
1293 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1294                             struct commit *restrict_revision,
1295                             struct object_id *head_oid, struct object_id *merge_base)
1296 {
1297         struct commit *head = lookup_commit(the_repository, head_oid);
1298         struct commit_list *merge_bases = NULL;
1299         int res = 0;
1300
1301         if (!head)
1302                 goto done;
1303
1304         merge_bases = get_merge_bases(onto, head);
1305         if (!merge_bases || merge_bases->next) {
1306                 oidcpy(merge_base, &null_oid);
1307                 goto done;
1308         }
1309
1310         oidcpy(merge_base, &merge_bases->item->object.oid);
1311         if (!oideq(merge_base, &onto->object.oid))
1312                 goto done;
1313
1314         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1315                 goto done;
1316
1317         if (!upstream)
1318                 goto done;
1319
1320         free_commit_list(merge_bases);
1321         merge_bases = get_merge_bases(upstream, head);
1322         if (!merge_bases || merge_bases->next)
1323                 goto done;
1324
1325         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1326                 goto done;
1327
1328         res = 1;
1329
1330 done:
1331         free_commit_list(merge_bases);
1332         return res && is_linear_history(onto, head);
1333 }
1334
1335 static int parse_opt_am(const struct option *opt, const char *arg, int unset)
1336 {
1337         struct rebase_options *opts = opt->value;
1338
1339         BUG_ON_OPT_NEG(unset);
1340         BUG_ON_OPT_ARG(arg);
1341
1342         opts->type = REBASE_APPLY;
1343
1344         return 0;
1345 }
1346
1347 /* -i followed by -m is still -i */
1348 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1349 {
1350         struct rebase_options *opts = opt->value;
1351
1352         BUG_ON_OPT_NEG(unset);
1353         BUG_ON_OPT_ARG(arg);
1354
1355         if (!is_merge(opts))
1356                 opts->type = REBASE_MERGE;
1357
1358         return 0;
1359 }
1360
1361 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1362 static int parse_opt_interactive(const struct option *opt, const char *arg,
1363                                  int unset)
1364 {
1365         struct rebase_options *opts = opt->value;
1366
1367         BUG_ON_OPT_NEG(unset);
1368         BUG_ON_OPT_ARG(arg);
1369
1370         opts->type = REBASE_MERGE;
1371         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1372
1373         return 0;
1374 }
1375
1376 static enum empty_type parse_empty_value(const char *value)
1377 {
1378         if (!strcasecmp(value, "drop"))
1379                 return EMPTY_DROP;
1380         else if (!strcasecmp(value, "keep"))
1381                 return EMPTY_KEEP;
1382         else if (!strcasecmp(value, "ask"))
1383                 return EMPTY_ASK;
1384
1385         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
1386 }
1387
1388 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
1389 {
1390         struct rebase_options *options = opt->value;
1391         enum empty_type value = parse_empty_value(arg);
1392
1393         BUG_ON_OPT_NEG(unset);
1394
1395         options->empty = value;
1396         return 0;
1397 }
1398
1399 static void NORETURN error_on_missing_default_upstream(void)
1400 {
1401         struct branch *current_branch = branch_get(NULL);
1402
1403         printf(_("%s\n"
1404                  "Please specify which branch you want to rebase against.\n"
1405                  "See git-rebase(1) for details.\n"
1406                  "\n"
1407                  "    git rebase '<branch>'\n"
1408                  "\n"),
1409                 current_branch ? _("There is no tracking information for "
1410                         "the current branch.") :
1411                         _("You are not currently on a branch."));
1412
1413         if (current_branch) {
1414                 const char *remote = current_branch->remote_name;
1415
1416                 if (!remote)
1417                         remote = _("<remote>");
1418
1419                 printf(_("If you wish to set tracking information for this "
1420                          "branch you can do so with:\n"
1421                          "\n"
1422                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1423                          "\n"),
1424                        remote, current_branch->name);
1425         }
1426         exit(1);
1427 }
1428
1429 static void set_reflog_action(struct rebase_options *options)
1430 {
1431         const char *env;
1432         struct strbuf buf = STRBUF_INIT;
1433
1434         if (!is_merge(options))
1435                 return;
1436
1437         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1438         if (env && strcmp("rebase", env))
1439                 return; /* only override it if it is "rebase" */
1440
1441         strbuf_addf(&buf, "rebase (%s)", options->action);
1442         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1443         strbuf_release(&buf);
1444 }
1445
1446 static int check_exec_cmd(const char *cmd)
1447 {
1448         if (strchr(cmd, '\n'))
1449                 return error(_("exec commands cannot contain newlines"));
1450
1451         /* Does the command consist purely of whitespace? */
1452         if (!cmd[strspn(cmd, " \t\r\f\v")])
1453                 return error(_("empty exec command"));
1454
1455         return 0;
1456 }
1457
1458
1459 int cmd_rebase(int argc, const char **argv, const char *prefix)
1460 {
1461         struct rebase_options options = REBASE_OPTIONS_INIT;
1462         const char *branch_name;
1463         int ret, flags, total_argc, in_progress = 0;
1464         int keep_base = 0;
1465         int ok_to_skip_pre_rebase = 0;
1466         struct strbuf msg = STRBUF_INIT;
1467         struct strbuf revisions = STRBUF_INIT;
1468         struct strbuf buf = STRBUF_INIT;
1469         struct object_id merge_base;
1470         int ignore_whitespace = 0;
1471         enum action action = ACTION_NONE;
1472         const char *gpg_sign = NULL;
1473         struct string_list exec = STRING_LIST_INIT_NODUP;
1474         const char *rebase_merges = NULL;
1475         int fork_point = -1;
1476         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1477         struct object_id squash_onto;
1478         char *squash_onto_name = NULL;
1479         int reschedule_failed_exec = -1;
1480         int allow_preemptive_ff = 1;
1481         struct option builtin_rebase_options[] = {
1482                 OPT_STRING(0, "onto", &options.onto_name,
1483                            N_("revision"),
1484                            N_("rebase onto given branch instead of upstream")),
1485                 OPT_BOOL(0, "keep-base", &keep_base,
1486                          N_("use the merge-base of upstream and branch as the current base")),
1487                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1488                          N_("allow pre-rebase hook to run")),
1489                 OPT_NEGBIT('q', "quiet", &options.flags,
1490                            N_("be quiet. implies --no-stat"),
1491                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1492                 OPT_BIT('v', "verbose", &options.flags,
1493                         N_("display a diffstat of what changed upstream"),
1494                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1495                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1496                         N_("do not show diffstat of what changed upstream"),
1497                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1498                 OPT_BOOL(0, "signoff", &options.signoff,
1499                          N_("add a Signed-off-by: line to each commit")),
1500                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1501                                   &options.git_am_opts, NULL,
1502                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1503                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1504                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1505                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1506                                   N_("passed to 'git apply'"), 0),
1507                 OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
1508                          N_("ignore changes in whitespace")),
1509                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1510                                   N_("action"), N_("passed to 'git apply'"), 0),
1511                 OPT_BIT('f', "force-rebase", &options.flags,
1512                         N_("cherry-pick all commits, even if unchanged"),
1513                         REBASE_FORCE),
1514                 OPT_BIT(0, "no-ff", &options.flags,
1515                         N_("cherry-pick all commits, even if unchanged"),
1516                         REBASE_FORCE),
1517                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1518                             ACTION_CONTINUE),
1519                 OPT_CMDMODE(0, "skip", &action,
1520                             N_("skip current patch and continue"), ACTION_SKIP),
1521                 OPT_CMDMODE(0, "abort", &action,
1522                             N_("abort and check out the original branch"),
1523                             ACTION_ABORT),
1524                 OPT_CMDMODE(0, "quit", &action,
1525                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1526                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1527                             "during an interactive rebase"), ACTION_EDIT_TODO),
1528                 OPT_CMDMODE(0, "show-current-patch", &action,
1529                             N_("show the patch file being applied or merged"),
1530                             ACTION_SHOW_CURRENT_PATCH),
1531                 { OPTION_CALLBACK, 0, "apply", &options, NULL,
1532                         N_("use apply strategies to rebase"),
1533                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1534                         parse_opt_am },
1535                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1536                         N_("use merging strategies to rebase"),
1537                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1538                         parse_opt_merge },
1539                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1540                         N_("let the user edit the list of commits to rebase"),
1541                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1542                         parse_opt_interactive },
1543                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1544                               N_("(DEPRECATED) try to recreate merges instead of "
1545                                  "ignoring them"),
1546                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1547                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1548                 OPT_CALLBACK_F(0, "empty", &options, "{drop,keep,ask}",
1549                                N_("how to handle commits that become empty"),
1550                                PARSE_OPT_NONEG, parse_opt_empty),
1551                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
1552                         N_("(DEPRECATED) keep empty commits"),
1553                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1554                         parse_opt_keep_empty },
1555                 OPT_BOOL(0, "autosquash", &options.autosquash,
1556                          N_("move commits that begin with "
1557                             "squash!/fixup! under -i")),
1558                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1559                         N_("GPG-sign commits"),
1560                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1561                 OPT_BOOL(0, "autostash", &options.autostash,
1562                          N_("automatically stash/stash pop before and after")),
1563                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1564                                 N_("add exec lines after each commit of the "
1565                                    "editable list")),
1566                 OPT_BOOL_F(0, "allow-empty-message",
1567                            &options.allow_empty_message,
1568                            N_("allow rebasing commits with empty messages"),
1569                            PARSE_OPT_HIDDEN),
1570                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1571                         N_("mode"),
1572                         N_("try to rebase merges instead of skipping them"),
1573                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1574                 OPT_BOOL(0, "fork-point", &fork_point,
1575                          N_("use 'merge-base --fork-point' to refine upstream")),
1576                 OPT_STRING('s', "strategy", &options.strategy,
1577                            N_("strategy"), N_("use the given merge strategy")),
1578                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1579                                 N_("option"),
1580                                 N_("pass the argument through to the merge "
1581                                    "strategy")),
1582                 OPT_BOOL(0, "root", &options.root,
1583                          N_("rebase all reachable commits up to the root(s)")),
1584                 OPT_BOOL(0, "reschedule-failed-exec",
1585                          &reschedule_failed_exec,
1586                          N_("automatically re-schedule any `exec` that fails")),
1587                 OPT_END(),
1588         };
1589         int i;
1590
1591         if (argc == 2 && !strcmp(argv[1], "-h"))
1592                 usage_with_options(builtin_rebase_usage,
1593                                    builtin_rebase_options);
1594
1595         options.allow_empty_message = 1;
1596         git_config(rebase_config, &options);
1597
1598         if (options.use_legacy_rebase ||
1599             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1600                 warning(_("the rebase.useBuiltin support has been removed!\n"
1601                           "See its entry in 'git help config' for details."));
1602
1603         strbuf_reset(&buf);
1604         strbuf_addf(&buf, "%s/applying", apply_dir());
1605         if(file_exists(buf.buf))
1606                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1607
1608         if (is_directory(apply_dir())) {
1609                 options.type = REBASE_APPLY;
1610                 options.state_dir = apply_dir();
1611         } else if (is_directory(merge_dir())) {
1612                 strbuf_reset(&buf);
1613                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1614                 if (is_directory(buf.buf)) {
1615                         options.type = REBASE_PRESERVE_MERGES;
1616                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1617                 } else {
1618                         strbuf_reset(&buf);
1619                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1620                         if(file_exists(buf.buf)) {
1621                                 options.type = REBASE_MERGE;
1622                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1623                         } else
1624                                 options.type = REBASE_MERGE;
1625                 }
1626                 options.state_dir = merge_dir();
1627         }
1628
1629         if (options.type != REBASE_UNSPECIFIED)
1630                 in_progress = 1;
1631
1632         total_argc = argc;
1633         argc = parse_options(argc, argv, prefix,
1634                              builtin_rebase_options,
1635                              builtin_rebase_usage, 0);
1636
1637         if (action != ACTION_NONE && total_argc != 2) {
1638                 usage_with_options(builtin_rebase_usage,
1639                                    builtin_rebase_options);
1640         }
1641
1642         if (argc > 2)
1643                 usage_with_options(builtin_rebase_usage,
1644                                    builtin_rebase_options);
1645
1646         if (options.type == REBASE_PRESERVE_MERGES)
1647                 warning(_("git rebase --preserve-merges is deprecated. "
1648                           "Use --rebase-merges instead."));
1649
1650         if (keep_base) {
1651                 if (options.onto_name)
1652                         die(_("cannot combine '--keep-base' with '--onto'"));
1653                 if (options.root)
1654                         die(_("cannot combine '--keep-base' with '--root'"));
1655         }
1656
1657         if (action != ACTION_NONE && !in_progress)
1658                 die(_("No rebase in progress?"));
1659         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1660
1661         if (action == ACTION_EDIT_TODO && !is_merge(&options))
1662                 die(_("The --edit-todo action can only be used during "
1663                       "interactive rebase."));
1664
1665         if (trace2_is_enabled()) {
1666                 if (is_merge(&options))
1667                         trace2_cmd_mode("interactive");
1668                 else if (exec.nr)
1669                         trace2_cmd_mode("interactive-exec");
1670                 else
1671                         trace2_cmd_mode(action_names[action]);
1672         }
1673
1674         switch (action) {
1675         case ACTION_CONTINUE: {
1676                 struct object_id head;
1677                 struct lock_file lock_file = LOCK_INIT;
1678                 int fd;
1679
1680                 options.action = "continue";
1681                 set_reflog_action(&options);
1682
1683                 /* Sanity check */
1684                 if (get_oid("HEAD", &head))
1685                         die(_("Cannot read HEAD"));
1686
1687                 fd = hold_locked_index(&lock_file, 0);
1688                 if (repo_read_index(the_repository) < 0)
1689                         die(_("could not read index"));
1690                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1691                               NULL);
1692                 if (0 <= fd)
1693                         repo_update_index_if_able(the_repository, &lock_file);
1694                 rollback_lock_file(&lock_file);
1695
1696                 if (has_unstaged_changes(the_repository, 1)) {
1697                         puts(_("You must edit all merge conflicts and then\n"
1698                                "mark them as resolved using git add"));
1699                         exit(1);
1700                 }
1701                 if (read_basic_state(&options))
1702                         exit(1);
1703                 goto run_rebase;
1704         }
1705         case ACTION_SKIP: {
1706                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1707
1708                 options.action = "skip";
1709                 set_reflog_action(&options);
1710
1711                 rerere_clear(the_repository, &merge_rr);
1712                 string_list_clear(&merge_rr, 1);
1713
1714                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1715                                NULL, NULL) < 0)
1716                         die(_("could not discard worktree changes"));
1717                 remove_branch_state(the_repository, 0);
1718                 if (read_basic_state(&options))
1719                         exit(1);
1720                 goto run_rebase;
1721         }
1722         case ACTION_ABORT: {
1723                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1724                 options.action = "abort";
1725                 set_reflog_action(&options);
1726
1727                 rerere_clear(the_repository, &merge_rr);
1728                 string_list_clear(&merge_rr, 1);
1729
1730                 if (read_basic_state(&options))
1731                         exit(1);
1732                 if (reset_head(&options.orig_head, "reset",
1733                                options.head_name, RESET_HEAD_HARD,
1734                                NULL, NULL) < 0)
1735                         die(_("could not move back to %s"),
1736                             oid_to_hex(&options.orig_head));
1737                 remove_branch_state(the_repository, 0);
1738                 ret = !!finish_rebase(&options);
1739                 goto cleanup;
1740         }
1741         case ACTION_QUIT: {
1742                 if (options.type == REBASE_MERGE) {
1743                         struct replay_opts replay = REPLAY_OPTS_INIT;
1744
1745                         replay.action = REPLAY_INTERACTIVE_REBASE;
1746                         ret = !!sequencer_remove_state(&replay);
1747                 } else {
1748                         strbuf_reset(&buf);
1749                         strbuf_addstr(&buf, options.state_dir);
1750                         ret = !!remove_dir_recursively(&buf, 0);
1751                         if (ret)
1752                                 error(_("could not remove '%s'"),
1753                                        options.state_dir);
1754                 }
1755                 goto cleanup;
1756         }
1757         case ACTION_EDIT_TODO:
1758                 options.action = "edit-todo";
1759                 options.dont_finish_rebase = 1;
1760                 goto run_rebase;
1761         case ACTION_SHOW_CURRENT_PATCH:
1762                 options.action = "show-current-patch";
1763                 options.dont_finish_rebase = 1;
1764                 goto run_rebase;
1765         case ACTION_NONE:
1766                 break;
1767         default:
1768                 BUG("action: %d", action);
1769         }
1770
1771         /* Make sure no rebase is in progress */
1772         if (in_progress) {
1773                 const char *last_slash = strrchr(options.state_dir, '/');
1774                 const char *state_dir_base =
1775                         last_slash ? last_slash + 1 : options.state_dir;
1776                 const char *cmd_live_rebase =
1777                         "git rebase (--continue | --abort | --skip)";
1778                 strbuf_reset(&buf);
1779                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1780                 die(_("It seems that there is already a %s directory, and\n"
1781                       "I wonder if you are in the middle of another rebase.  "
1782                       "If that is the\n"
1783                       "case, please try\n\t%s\n"
1784                       "If that is not the case, please\n\t%s\n"
1785                       "and run me again.  I am stopping in case you still "
1786                       "have something\n"
1787                       "valuable there.\n"),
1788                     state_dir_base, cmd_live_rebase, buf.buf);
1789         }
1790
1791         if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
1792             (action != ACTION_NONE) ||
1793             (exec.nr > 0) ||
1794             options.autosquash) {
1795                 allow_preemptive_ff = 0;
1796         }
1797
1798         for (i = 0; i < options.git_am_opts.argc; i++) {
1799                 const char *option = options.git_am_opts.argv[i], *p;
1800                 if (!strcmp(option, "--committer-date-is-author-date") ||
1801                     !strcmp(option, "--ignore-date") ||
1802                     !strcmp(option, "--whitespace=fix") ||
1803                     !strcmp(option, "--whitespace=strip"))
1804                         allow_preemptive_ff = 0;
1805                 else if (skip_prefix(option, "-C", &p)) {
1806                         while (*p)
1807                                 if (!isdigit(*(p++)))
1808                                         die(_("switch `C' expects a "
1809                                               "numerical value"));
1810                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1811                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1812                             strcmp(p, "error") && strcmp(p, "error-all"))
1813                                 die("Invalid whitespace option: '%s'", p);
1814                 }
1815         }
1816
1817         for (i = 0; i < exec.nr; i++)
1818                 if (check_exec_cmd(exec.items[i].string))
1819                         exit(1);
1820
1821         if (!(options.flags & REBASE_NO_QUIET))
1822                 argv_array_push(&options.git_am_opts, "-q");
1823
1824         if (options.empty != EMPTY_UNSPECIFIED)
1825                 imply_merge(&options, "--empty");
1826
1827         if (gpg_sign) {
1828                 free(options.gpg_sign_opt);
1829                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1830         }
1831
1832         if (exec.nr) {
1833                 int i;
1834
1835                 imply_merge(&options, "--exec");
1836
1837                 strbuf_reset(&buf);
1838                 for (i = 0; i < exec.nr; i++)
1839                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1840                 options.cmd = xstrdup(buf.buf);
1841         }
1842
1843         if (rebase_merges) {
1844                 if (!*rebase_merges)
1845                         ; /* default mode; do nothing */
1846                 else if (!strcmp("rebase-cousins", rebase_merges))
1847                         options.rebase_cousins = 1;
1848                 else if (strcmp("no-rebase-cousins", rebase_merges))
1849                         die(_("Unknown mode: %s"), rebase_merges);
1850                 options.rebase_merges = 1;
1851                 imply_merge(&options, "--rebase-merges");
1852         }
1853
1854         if (options.type == REBASE_APPLY) {
1855                 if (ignore_whitespace)
1856                         argv_array_push(&options.git_am_opts,
1857                                         "--ignore-whitespace");
1858         } else {
1859                 /* REBASE_MERGE and PRESERVE_MERGES */
1860                 if (ignore_whitespace) {
1861                         string_list_append(&strategy_options,
1862                                            "ignore-space-change");
1863                 }
1864         }
1865
1866         if (strategy_options.nr) {
1867                 int i;
1868
1869                 if (!options.strategy)
1870                         options.strategy = "recursive";
1871
1872                 strbuf_reset(&buf);
1873                 for (i = 0; i < strategy_options.nr; i++)
1874                         strbuf_addf(&buf, " --%s",
1875                                     strategy_options.items[i].string);
1876                 options.strategy_opts = xstrdup(buf.buf);
1877         }
1878
1879         if (options.strategy) {
1880                 options.strategy = xstrdup(options.strategy);
1881                 switch (options.type) {
1882                 case REBASE_APPLY:
1883                         die(_("--strategy requires --merge or --interactive"));
1884                 case REBASE_MERGE:
1885                 case REBASE_PRESERVE_MERGES:
1886                         /* compatible */
1887                         break;
1888                 case REBASE_UNSPECIFIED:
1889                         options.type = REBASE_MERGE;
1890                         break;
1891                 default:
1892                         BUG("unhandled rebase type (%d)", options.type);
1893                 }
1894         }
1895
1896         if (options.type == REBASE_MERGE)
1897                 imply_merge(&options, "--merge");
1898
1899         if (options.root && !options.onto_name)
1900                 imply_merge(&options, "--root without --onto");
1901
1902         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1903                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1904
1905         if (options.git_am_opts.argc || options.type == REBASE_APPLY) {
1906                 /* all am options except -q are compatible only with --apply */
1907                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1908                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1909                                 break;
1910
1911                 if (i >= 0) {
1912                         if (is_merge(&options))
1913                                 die(_("cannot combine apply options with "
1914                                       "merge options"));
1915                         else
1916                                 options.type = REBASE_APPLY;
1917                 }
1918         }
1919
1920         if (options.type == REBASE_UNSPECIFIED) {
1921                 if (!strcmp(options.default_backend, "merge"))
1922                         imply_merge(&options, "--merge");
1923                 else if (!strcmp(options.default_backend, "apply"))
1924                         options.type = REBASE_APPLY;
1925                 else
1926                         die(_("Unknown rebase backend: %s"),
1927                             options.default_backend);
1928         }
1929
1930         switch (options.type) {
1931         case REBASE_MERGE:
1932         case REBASE_PRESERVE_MERGES:
1933                 options.state_dir = merge_dir();
1934                 break;
1935         case REBASE_APPLY:
1936                 options.state_dir = apply_dir();
1937                 break;
1938         default:
1939                 BUG("options.type was just set above; should be unreachable.");
1940         }
1941
1942         if (options.empty == EMPTY_UNSPECIFIED) {
1943                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1944                         options.empty = EMPTY_ASK;
1945                 else if (exec.nr > 0)
1946                         options.empty = EMPTY_KEEP;
1947                 else
1948                         options.empty = EMPTY_DROP;
1949         }
1950         if (reschedule_failed_exec > 0 && !is_merge(&options))
1951                 die(_("--reschedule-failed-exec requires "
1952                       "--exec or --interactive"));
1953         if (reschedule_failed_exec >= 0)
1954                 options.reschedule_failed_exec = reschedule_failed_exec;
1955
1956         if (options.signoff) {
1957                 if (options.type == REBASE_PRESERVE_MERGES)
1958                         die("cannot combine '--signoff' with "
1959                             "'--preserve-merges'");
1960                 argv_array_push(&options.git_am_opts, "--signoff");
1961                 options.flags |= REBASE_FORCE;
1962         }
1963
1964         if (options.type == REBASE_PRESERVE_MERGES) {
1965                 /*
1966                  * Note: incompatibility with --signoff handled in signoff block above
1967                  * Note: incompatibility with --interactive is just a strong warning;
1968                  *       git-rebase.txt caveats with "unless you know what you are doing"
1969                  */
1970                 if (options.rebase_merges)
1971                         die(_("cannot combine '--preserve-merges' with "
1972                               "'--rebase-merges'"));
1973
1974                 if (options.reschedule_failed_exec)
1975                         die(_("error: cannot combine '--preserve-merges' with "
1976                               "'--reschedule-failed-exec'"));
1977         }
1978
1979         if (!options.root) {
1980                 if (argc < 1) {
1981                         struct branch *branch;
1982
1983                         branch = branch_get(NULL);
1984                         options.upstream_name = branch_get_upstream(branch,
1985                                                                     NULL);
1986                         if (!options.upstream_name)
1987                                 error_on_missing_default_upstream();
1988                         if (fork_point < 0)
1989                                 fork_point = 1;
1990                 } else {
1991                         options.upstream_name = argv[0];
1992                         argc--;
1993                         argv++;
1994                         if (!strcmp(options.upstream_name, "-"))
1995                                 options.upstream_name = "@{-1}";
1996                 }
1997                 options.upstream = peel_committish(options.upstream_name);
1998                 if (!options.upstream)
1999                         die(_("invalid upstream '%s'"), options.upstream_name);
2000                 options.upstream_arg = options.upstream_name;
2001         } else {
2002                 if (!options.onto_name) {
2003                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
2004                                         &squash_onto, NULL, NULL) < 0)
2005                                 die(_("Could not create new root commit"));
2006                         options.squash_onto = &squash_onto;
2007                         options.onto_name = squash_onto_name =
2008                                 xstrdup(oid_to_hex(&squash_onto));
2009                 } else
2010                         options.root_with_onto = 1;
2011
2012                 options.upstream_name = NULL;
2013                 options.upstream = NULL;
2014                 if (argc > 1)
2015                         usage_with_options(builtin_rebase_usage,
2016                                            builtin_rebase_options);
2017                 options.upstream_arg = "--root";
2018         }
2019
2020         /* Make sure the branch to rebase onto is valid. */
2021         if (keep_base) {
2022                 strbuf_reset(&buf);
2023                 strbuf_addstr(&buf, options.upstream_name);
2024                 strbuf_addstr(&buf, "...");
2025                 options.onto_name = xstrdup(buf.buf);
2026         } else if (!options.onto_name)
2027                 options.onto_name = options.upstream_name;
2028         if (strstr(options.onto_name, "...")) {
2029                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
2030                         if (keep_base)
2031                                 die(_("'%s': need exactly one merge base with branch"),
2032                                     options.upstream_name);
2033                         else
2034                                 die(_("'%s': need exactly one merge base"),
2035                                     options.onto_name);
2036                 }
2037                 options.onto = lookup_commit_or_die(&merge_base,
2038                                                     options.onto_name);
2039         } else {
2040                 options.onto = peel_committish(options.onto_name);
2041                 if (!options.onto)
2042                         die(_("Does not point to a valid commit '%s'"),
2043                                 options.onto_name);
2044         }
2045
2046         /*
2047          * If the branch to rebase is given, that is the branch we will rebase
2048          * branch_name -- branch/commit being rebased, or
2049          *                HEAD (already detached)
2050          * orig_head -- commit object name of tip of the branch before rebasing
2051          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
2052          */
2053         if (argc == 1) {
2054                 /* Is it "rebase other branchname" or "rebase other commit"? */
2055                 branch_name = argv[0];
2056                 options.switch_to = argv[0];
2057
2058                 /* Is it a local branch? */
2059                 strbuf_reset(&buf);
2060                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
2061                 if (!read_ref(buf.buf, &options.orig_head)) {
2062                         die_if_checked_out(buf.buf, 1);
2063                         options.head_name = xstrdup(buf.buf);
2064                 /* If not is it a valid ref (branch or commit)? */
2065                 } else if (!get_oid(branch_name, &options.orig_head))
2066                         options.head_name = NULL;
2067                 else
2068                         die(_("fatal: no such branch/commit '%s'"),
2069                             branch_name);
2070         } else if (argc == 0) {
2071                 /* Do not need to switch branches, we are already on it. */
2072                 options.head_name =
2073                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
2074                                          &flags));
2075                 if (!options.head_name)
2076                         die(_("No such ref: %s"), "HEAD");
2077                 if (flags & REF_ISSYMREF) {
2078                         if (!skip_prefix(options.head_name,
2079                                          "refs/heads/", &branch_name))
2080                                 branch_name = options.head_name;
2081
2082                 } else {
2083                         FREE_AND_NULL(options.head_name);
2084                         branch_name = "HEAD";
2085                 }
2086                 if (get_oid("HEAD", &options.orig_head))
2087                         die(_("Could not resolve HEAD to a revision"));
2088         } else
2089                 BUG("unexpected number of arguments left to parse");
2090
2091         if (fork_point > 0) {
2092                 struct commit *head =
2093                         lookup_commit_reference(the_repository,
2094                                                 &options.orig_head);
2095                 options.restrict_revision =
2096                         get_fork_point(options.upstream_name, head);
2097         }
2098
2099         if (repo_read_index(the_repository) < 0)
2100                 die(_("could not read index"));
2101
2102         if (options.autostash) {
2103                 struct lock_file lock_file = LOCK_INIT;
2104                 int fd;
2105
2106                 fd = hold_locked_index(&lock_file, 0);
2107                 refresh_cache(REFRESH_QUIET);
2108                 if (0 <= fd)
2109                         repo_update_index_if_able(the_repository, &lock_file);
2110                 rollback_lock_file(&lock_file);
2111
2112                 if (has_unstaged_changes(the_repository, 1) ||
2113                     has_uncommitted_changes(the_repository, 1)) {
2114                         const char *autostash =
2115                                 state_dir_path("autostash", &options);
2116                         struct child_process stash = CHILD_PROCESS_INIT;
2117                         struct object_id oid;
2118
2119                         argv_array_pushl(&stash.args,
2120                                          "stash", "create", "autostash", NULL);
2121                         stash.git_cmd = 1;
2122                         stash.no_stdin = 1;
2123                         strbuf_reset(&buf);
2124                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
2125                                 die(_("Cannot autostash"));
2126                         strbuf_trim_trailing_newline(&buf);
2127                         if (get_oid(buf.buf, &oid))
2128                                 die(_("Unexpected stash response: '%s'"),
2129                                     buf.buf);
2130                         strbuf_reset(&buf);
2131                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
2132
2133                         if (safe_create_leading_directories_const(autostash))
2134                                 die(_("Could not create directory for '%s'"),
2135                                     options.state_dir);
2136                         write_file(autostash, "%s", oid_to_hex(&oid));
2137                         printf(_("Created autostash: %s\n"), buf.buf);
2138                         if (reset_head(NULL, "reset --hard",
2139                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2140                                 die(_("could not reset --hard"));
2141
2142                         if (discard_index(the_repository->index) < 0 ||
2143                                 repo_read_index(the_repository) < 0)
2144                                 die(_("could not read index"));
2145                 }
2146         }
2147
2148         if (require_clean_work_tree(the_repository, "rebase",
2149                                     _("Please commit or stash them."), 1, 1)) {
2150                 ret = 1;
2151                 goto cleanup;
2152         }
2153
2154         /*
2155          * Now we are rebasing commits upstream..orig_head (or with --root,
2156          * everything leading up to orig_head) on top of onto.
2157          */
2158
2159         /*
2160          * Check if we are already based on onto with linear history,
2161          * in which case we could fast-forward without replacing the commits
2162          * with new commits recreated by replaying their changes.
2163          *
2164          * Note that can_fast_forward() initializes merge_base, so we have to
2165          * call it before checking allow_preemptive_ff.
2166          */
2167         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
2168                     &options.orig_head, &merge_base) &&
2169             allow_preemptive_ff) {
2170                 int flag;
2171
2172                 if (!(options.flags & REBASE_FORCE)) {
2173                         /* Lazily switch to the target branch if needed... */
2174                         if (options.switch_to) {
2175                                 strbuf_reset(&buf);
2176                                 strbuf_addf(&buf, "%s: checkout %s",
2177                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2178                                             options.switch_to);
2179                                 if (reset_head(&options.orig_head, "checkout",
2180                                                options.head_name,
2181                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2182                                                NULL, buf.buf) < 0) {
2183                                         ret = !!error(_("could not switch to "
2184                                                         "%s"),
2185                                                       options.switch_to);
2186                                         goto cleanup;
2187                                 }
2188                         }
2189
2190                         if (!(options.flags & REBASE_NO_QUIET))
2191                                 ; /* be quiet */
2192                         else if (!strcmp(branch_name, "HEAD") &&
2193                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2194                                 puts(_("HEAD is up to date."));
2195                         else
2196                                 printf(_("Current branch %s is up to date.\n"),
2197                                        branch_name);
2198                         ret = !!finish_rebase(&options);
2199                         goto cleanup;
2200                 } else 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, rebase forced."));
2205                 else
2206                         printf(_("Current branch %s is up to date, rebase "
2207                                  "forced.\n"), branch_name);
2208         }
2209
2210         /* If a hook exists, give it a chance to interrupt*/
2211         if (!ok_to_skip_pre_rebase &&
2212             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2213                         argc ? argv[0] : NULL, NULL))
2214                 die(_("The pre-rebase hook refused to rebase."));
2215
2216         if (options.flags & REBASE_DIFFSTAT) {
2217                 struct diff_options opts;
2218
2219                 if (options.flags & REBASE_VERBOSE) {
2220                         if (is_null_oid(&merge_base))
2221                                 printf(_("Changes to %s:\n"),
2222                                        oid_to_hex(&options.onto->object.oid));
2223                         else
2224                                 printf(_("Changes from %s to %s:\n"),
2225                                        oid_to_hex(&merge_base),
2226                                        oid_to_hex(&options.onto->object.oid));
2227                 }
2228
2229                 /* We want color (if set), but no pager */
2230                 diff_setup(&opts);
2231                 opts.stat_width = -1; /* use full terminal width */
2232                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2233                 opts.output_format |=
2234                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2235                 opts.detect_rename = DIFF_DETECT_RENAME;
2236                 diff_setup_done(&opts);
2237                 diff_tree_oid(is_null_oid(&merge_base) ?
2238                               the_hash_algo->empty_tree : &merge_base,
2239                               &options.onto->object.oid, "", &opts);
2240                 diffcore_std(&opts);
2241                 diff_flush(&opts);
2242         }
2243
2244         if (is_merge(&options))
2245                 goto run_rebase;
2246
2247         /* Detach HEAD and reset the tree */
2248         if (options.flags & REBASE_NO_QUIET)
2249                 printf(_("First, rewinding head to replay your work on top of "
2250                          "it...\n"));
2251
2252         strbuf_addf(&msg, "%s: checkout %s",
2253                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2254         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2255                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2256                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2257                        NULL, msg.buf))
2258                 die(_("Could not detach HEAD"));
2259         strbuf_release(&msg);
2260
2261         /*
2262          * If the onto is a proper descendant of the tip of the branch, then
2263          * we just fast-forwarded.
2264          */
2265         strbuf_reset(&msg);
2266         if (oideq(&merge_base, &options.orig_head)) {
2267                 printf(_("Fast-forwarded %s to %s.\n"),
2268                         branch_name, options.onto_name);
2269                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2270                         options.head_name ? options.head_name : "detached HEAD",
2271                         oid_to_hex(&options.onto->object.oid));
2272                 reset_head(NULL, "Fast-forwarded", options.head_name,
2273                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2274                 strbuf_release(&msg);
2275                 ret = !!finish_rebase(&options);
2276                 goto cleanup;
2277         }
2278
2279         strbuf_addf(&revisions, "%s..%s",
2280                     options.root ? oid_to_hex(&options.onto->object.oid) :
2281                     (options.restrict_revision ?
2282                      oid_to_hex(&options.restrict_revision->object.oid) :
2283                      oid_to_hex(&options.upstream->object.oid)),
2284                     oid_to_hex(&options.orig_head));
2285
2286         options.revisions = revisions.buf;
2287
2288 run_rebase:
2289         ret = !!run_specific_rebase(&options, action);
2290
2291 cleanup:
2292         strbuf_release(&buf);
2293         strbuf_release(&revisions);
2294         free(options.head_name);
2295         free(options.gpg_sign_opt);
2296         free(options.cmd);
2297         free(squash_onto_name);
2298         return ret;
2299 }