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         if (opts->strategy_opts)
 130                 parse_strategy_opts(&replay, opts->strategy_opts);
 131
 132         if (opts->squash_onto) {
 133                 oidcpy(&replay.squash_onto, opts->squash_onto);
 134                 replay.have_squash_onto = 1;
 135         }
 136
 137         return replay;
 138 }
 139
 140 enum action {
 141         ACTION_NONE = 0,
 142         ACTION_CONTINUE,
 143         ACTION_SKIP,
 144         ACTION_ABORT,
 145         ACTION_QUIT,
 146         ACTION_EDIT_TODO,
 147         ACTION_SHOW_CURRENT_PATCH,
 148         ACTION_SHORTEN_OIDS,
 149         ACTION_EXPAND_OIDS,
 150         ACTION_CHECK_TODO_LIST,
 151         ACTION_REARRANGE_SQUASH,
 152         ACTION_ADD_EXEC
 153 };
 154
 155 static const char *action_names[] = { "undefined",
 156                                       "continue",
 157                                       "skip",
 158                                       "abort",
 159                                       "quit",
 160                                       "edit_todo",
 161                                       "show_current_patch" };
 162
 163 static int add_exec_commands(struct string_list *commands)
 164 {
 165         const char *todo_file = rebase_path_todo();
 166         struct todo_list todo_list = TODO_LIST_INIT;
 167         int res;
 168
 169         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 170                 return error_errno(_("could not read '%s'."), todo_file);
 171
 172         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 173                                         &todo_list)) {
 174                 todo_list_release(&todo_list);
 175                 return error(_("unusable todo list: '%s'"), todo_file);
 176         }
 177
 178         todo_list_add_exec_commands(&todo_list, commands);
 179         res = todo_list_write_to_file(the_repository, &todo_list,
 180                                       todo_file, NULL, NULL, -1, 0);
 181         todo_list_release(&todo_list);
 182
 183         if (res)
 184                 return error_errno(_("could not write '%s'."), todo_file);
 185         return 0;
 186 }
 187
 188 static int rearrange_squash_in_todo_file(void)
 189 {
 190         const char *todo_file = rebase_path_todo();
 191         struct todo_list todo_list = TODO_LIST_INIT;
 192         int res = 0;
 193
 194         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 195                 return error_errno(_("could not read '%s'."), todo_file);
 196         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 197                                         &todo_list)) {
 198                 todo_list_release(&todo_list);
 199                 return error(_("unusable todo list: '%s'"), todo_file);
 200         }
 201
 202         res = todo_list_rearrange_squash(&todo_list);
 203         if (!res)
 204                 res = todo_list_write_to_file(the_repository, &todo_list,
 205                                               todo_file, NULL, NULL, -1, 0);
 206
 207         todo_list_release(&todo_list);
 208
 209         if (res)
 210                 return error_errno(_("could not write '%s'."), todo_file);
 211         return 0;
 212 }
 213
 214 static int transform_todo_file(unsigned flags)
 215 {
 216         const char *todo_file = rebase_path_todo();
 217         struct todo_list todo_list = TODO_LIST_INIT;
 218         int res;
 219
 220         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 221                 return error_errno(_("could not read '%s'."), todo_file);
 222
 223         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 224                                         &todo_list)) {
 225                 todo_list_release(&todo_list);
 226                 return error(_("unusable todo list: '%s'"), todo_file);
 227         }
 228
 229         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 230                                       NULL, NULL, -1, flags);
 231         todo_list_release(&todo_list);
 232
 233         if (res)
 234                 return error_errno(_("could not write '%s'."), todo_file);
 235         return 0;
 236 }
 237
 238 static int edit_todo_file(unsigned flags)
 239 {
 240         const char *todo_file = rebase_path_todo();
 241         struct todo_list todo_list = TODO_LIST_INIT,
 242                 new_todo = TODO_LIST_INIT;
 243         int res = 0;
 244
 245         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 246                 return error_errno(_("could not read '%s'."), todo_file);
 247
 248         strbuf_stripspace(&todo_list.buf, 1);
 249         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 250         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 251                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 252                 res = error_errno(_("could not write '%s'"), todo_file);
 253
 254         todo_list_release(&todo_list);
 255         todo_list_release(&new_todo);
 256
 257         return res;
 258 }
 259
 260 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 261                                struct object_id *orig_head, const char **head_hash,
 262                                char **revisions, char **shortrevisions)
 263 {
 264         struct commit *base_rev = upstream ? upstream : onto;
 265         const char *shorthead;
 266
 267         *head_hash = find_unique_abbrev(orig_head, GIT_MAX_HEXSZ);
 268         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 269                                                    *head_hash);
 270
 271         shorthead = find_unique_abbrev(orig_head, DEFAULT_ABBREV);
 272
 273         if (upstream) {
 274                 const char *shortrev;
 275
 276                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 277                                               DEFAULT_ABBREV);
 278
 279                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 280         } else
 281                 *shortrevisions = xstrdup(shorthead);
 282
 283         return 0;
 284 }
 285
 286 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 287                             struct commit *onto, const char *orig_head)
 288 {
 289         FILE *interactive;
 290
 291         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 292                 return error_errno(_("could not create temporary %s"), merge_dir());
 293
 294         delete_reflog("REBASE_HEAD");
 295
 296         interactive = fopen(path_interactive(), "w");
 297         if (!interactive)
 298                 return error_errno(_("could not mark as interactive"));
 299         fclose(interactive);
 300
 301         return write_basic_state(opts, head_name, onto, orig_head);
 302 }
 303
 304 static void split_exec_commands(const char *cmd, struct string_list *commands)
 305 {
 306         if (cmd && *cmd) {
 307                 string_list_split(commands, cmd, '\n', -1);
 308
 309                 /* rebase.c adds a new line to cmd after every command,
 310                  * so here the last command is always empty */
 311                 string_list_remove_empty_items(commands, 0);
 312         }
 313 }
 314
 315 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 316 {
 317         int ret;
 318         const char *head_hash = NULL;
 319         char *revisions = NULL, *shortrevisions = NULL;
 320         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 321         struct todo_list todo_list = TODO_LIST_INIT;
 322         struct replay_opts replay = get_replay_opts(opts);
 323         struct string_list commands = STRING_LIST_INIT_DUP;
 324
 325         if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head,
 326                                 &head_hash, &revisions, &shortrevisions))
 327                 return -1;
 328
 329         if (init_basic_state(&replay,
 330                              opts->head_name ? opts->head_name : "detached HEAD",
 331                              opts->onto, head_hash)) {
 332                 free(revisions);
 333                 free(shortrevisions);
 334
 335                 return -1;
 336         }
 337
 338         if (!opts->upstream && opts->squash_onto)
 339                 write_file(path_squash_onto(), "%s\n",
 340                            oid_to_hex(opts->squash_onto));
 341
 342         argv_array_pushl(&make_script_args, "", revisions, NULL);
 343         if (opts->restrict_revision)
 344                 argv_array_pushf(&make_script_args, "^%s",
 345                                  oid_to_hex(&opts->restrict_revision->object.oid));
 346
 347         ret = sequencer_make_script(the_repository, &todo_list.buf,
 348                                     make_script_args.argc, make_script_args.argv,
 349                                     flags);
 350
 351         if (ret)
 352                 error(_("could not generate todo list"));
 353         else {
 354                 discard_cache();
 355                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 356                                                 &todo_list))
 357                         BUG("unusable todo list");
 358
 359                 split_exec_commands(opts->cmd, &commands);
 360                 ret = complete_action(the_repository, &replay, flags,
 361                         shortrevisions, opts->onto_name, opts->onto, head_hash,
 362                         &commands, opts->autosquash, &todo_list);
 363         }
 364
 365         string_list_clear(&commands, 0);
 366         free(revisions);
 367         free(shortrevisions);
 368         todo_list_release(&todo_list);
 369         argv_array_clear(&make_script_args);
 370
 371         return ret;
 372 }
 373
 374 static int run_sequencer_rebase(struct rebase_options *opts,
 375                                   enum action command)
 376 {
 377         unsigned flags = 0;
 378         int abbreviate_commands = 0, ret = 0;
 379
 380         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 381
 382         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 383         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 384         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 385         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 386         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 387
 388         switch (command) {
 389         case ACTION_NONE: {
 390                 if (!opts->onto && !opts->upstream)
 391                         die(_("a base commit must be provided with --upstream or --onto"));
 392
 393                 ret = do_interactive_rebase(opts, flags);
 394                 break;
 395         }
 396         case ACTION_SKIP: {
 397                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 398
 399                 rerere_clear(the_repository, &merge_rr);
 400         }
 401                 /* fallthrough */
 402         case ACTION_CONTINUE: {
 403                 struct replay_opts replay_opts = get_replay_opts(opts);
 404
 405                 ret = sequencer_continue(the_repository, &replay_opts);
 406                 break;
 407         }
 408         case ACTION_EDIT_TODO:
 409                 ret = edit_todo_file(flags);
 410                 break;
 411         case ACTION_SHOW_CURRENT_PATCH: {
 412                 struct child_process cmd = CHILD_PROCESS_INIT;
 413
 414                 cmd.git_cmd = 1;
 415                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 416                 ret = run_command(&cmd);
 417
 418                 break;
 419         }
 420         case ACTION_SHORTEN_OIDS:
 421         case ACTION_EXPAND_OIDS:
 422                 ret = transform_todo_file(flags);
 423                 break;
 424         case ACTION_CHECK_TODO_LIST:
 425                 ret = check_todo_list_from_file(the_repository);
 426                 break;
 427         case ACTION_REARRANGE_SQUASH:
 428                 ret = rearrange_squash_in_todo_file();
 429                 break;
 430         case ACTION_ADD_EXEC: {
 431                 struct string_list commands = STRING_LIST_INIT_DUP;
 432
 433                 split_exec_commands(opts->cmd, &commands);
 434                 ret = add_exec_commands(&commands);
 435                 string_list_clear(&commands, 0);
 436                 break;
 437         }
 438         default:
 439                 BUG("invalid command '%d'", command);
 440         }
 441
 442         return ret;
 443 }
 444
 445 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 446                                 int unset)
 447 {
 448         struct rebase_options *opts = opt->value;
 449
 450         BUG_ON_OPT_ARG(arg);
 451
 452         /*
 453          * If we ever want to remap --keep-empty to --empty=keep, insert:
 454          *      opts->empty = unset ? EMPTY_UNSPECIFIED : EMPTY_KEEP;
 455          */
 456         opts->type = REBASE_MERGE;
 457         return 0;
 458 }
 459
 460 static const char * const builtin_rebase_interactive_usage[] = {
 461         N_("git rebase--interactive [<options>]"),
 462         NULL
 463 };
 464
 465 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 466 {
 467         struct rebase_options opts = REBASE_OPTIONS_INIT;
 468         struct object_id squash_onto = null_oid;
 469         enum action command = ACTION_NONE;
 470         struct option options[] = {
 471                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 472                            REBASE_FORCE),
 473                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
 474                         N_("(DEPRECATED) keep empty commits"),
 475                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
 476                         parse_opt_keep_empty },
 477                 OPT_BOOL_F(0, "allow-empty-message", &opts.allow_empty_message,
 478                            N_("allow commits with empty messages"),
 479                            PARSE_OPT_HIDDEN),
 480                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 481                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 482                          N_("keep original branch points of cousins")),
 483                 OPT_BOOL(0, "autosquash", &opts.autosquash,
 484                          N_("move commits that begin with squash!/fixup!")),
 485                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 486                 OPT_BIT('v', "verbose", &opts.flags,
 487                         N_("display a diffstat of what changed upstream"),
 488                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 489                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 490                             ACTION_CONTINUE),
 491                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 492                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 493                             ACTION_EDIT_TODO),
 494                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 495                             ACTION_SHOW_CURRENT_PATCH),
 496                 OPT_CMDMODE(0, "shorten-ids", &command,
 497                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 498                 OPT_CMDMODE(0, "expand-ids", &command,
 499                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 500                 OPT_CMDMODE(0, "check-todo-list", &command,
 501                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 502                 OPT_CMDMODE(0, "rearrange-squash", &command,
 503                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 504                 OPT_CMDMODE(0, "add-exec-commands", &command,
 505                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 506                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 507                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 508                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 509                   N_("restrict-revision"), N_("restrict revision"),
 510                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 511                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 512                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 513                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 514                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 515                   0 },
 516                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 517                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 518                         N_("GPG-sign commits"),
 519                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 520                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 521                            N_("rebase strategy")),
 522                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 523                            N_("strategy options")),
 524                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 525                            N_("the branch or commit to checkout")),
 526                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 527                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 528                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 529                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 530                          N_("automatically re-schedule any `exec` that fails")),
 531                 OPT_END()
 532         };
 533
 534         opts.rebase_cousins = -1;
 535
 536         if (argc == 1)
 537                 usage_with_options(builtin_rebase_interactive_usage, options);
 538
 539         argc = parse_options(argc, argv, prefix, options,
 540                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 541
 542         if (!is_null_oid(&squash_onto))
 543                 opts.squash_onto = &squash_onto;
 544
 545         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 546                 warning(_("--[no-]rebase-cousins has no effect without "
 547                           "--rebase-merges"));
 548
 549         return !!run_sequencer_rebase(&opts, command);
 550 }
 551
 552 static int is_merge(struct rebase_options *opts)
 553 {
 554         return opts->type == REBASE_MERGE ||
 555                 opts->type == REBASE_PRESERVE_MERGES;
 556 }
 557
 558 static void imply_merge(struct rebase_options *opts, const char *option)
 559 {
 560         switch (opts->type) {
 561         case REBASE_APPLY:
 562                 die(_("%s requires an interactive rebase"), option);
 563                 break;
 564         case REBASE_MERGE:
 565         case REBASE_PRESERVE_MERGES:
 566                 break;
 567         default:
 568                 opts->type = REBASE_MERGE; /* implied */
 569                 break;
 570         }
 571 }
 572
 573 /* Returns the filename prefixed by the state_dir */
 574 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 575 {
 576         static struct strbuf path = STRBUF_INIT;
 577         static size_t prefix_len;
 578
 579         if (!prefix_len) {
 580                 strbuf_addf(&path, "%s/", opts->state_dir);
 581                 prefix_len = path.len;
 582         }
 583
 584         strbuf_setlen(&path, prefix_len);
 585         strbuf_addstr(&path, filename);
 586         return path.buf;
 587 }
 588
 589 /* Read one file, then strip line endings */
 590 static int read_one(const char *path, struct strbuf *buf)
 591 {
 592         if (strbuf_read_file(buf, path, 0) < 0)
 593                 return error_errno(_("could not read '%s'"), path);
 594         strbuf_trim_trailing_newline(buf);
 595         return 0;
 596 }
 597
 598 /* Initialize the rebase options from the state directory. */
 599 static int read_basic_state(struct rebase_options *opts)
 600 {
 601         struct strbuf head_name = STRBUF_INIT;
 602         struct strbuf buf = STRBUF_INIT;
 603         struct object_id oid;
 604
 605         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 606             read_one(state_dir_path("onto", opts), &buf))
 607                 return -1;
 608         opts->head_name = starts_with(head_name.buf, "refs/") ?
 609                 xstrdup(head_name.buf) : NULL;
 610         strbuf_release(&head_name);
 611         if (get_oid(buf.buf, &oid))
 612                 return error(_("could not get 'onto': '%s'"), buf.buf);
 613         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 614
 615         /*
 616          * We always write to orig-head, but interactive rebase used to write to
 617          * head. Fall back to reading from head to cover for the case that the
 618          * user upgraded git with an ongoing interactive rebase.
 619          */
 620         strbuf_reset(&buf);
 621         if (file_exists(state_dir_path("orig-head", opts))) {
 622                 if (read_one(state_dir_path("orig-head", opts), &buf))
 623                         return -1;
 624         } else if (read_one(state_dir_path("head", opts), &buf))
 625                 return -1;
 626         if (get_oid(buf.buf, &opts->orig_head))
 627                 return error(_("invalid orig-head: '%s'"), buf.buf);
 628
 629         if (file_exists(state_dir_path("quiet", opts)))
 630                 opts->flags &= ~REBASE_NO_QUIET;
 631         else
 632                 opts->flags |= REBASE_NO_QUIET;
 633
 634         if (file_exists(state_dir_path("verbose", opts)))
 635                 opts->flags |= REBASE_VERBOSE;
 636
 637         if (file_exists(state_dir_path("signoff", opts))) {
 638                 opts->signoff = 1;
 639                 opts->flags |= REBASE_FORCE;
 640         }
 641
 642         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 643                 strbuf_reset(&buf);
 644                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 645                             &buf))
 646                         return -1;
 647                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 648                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 649                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 650                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 651                 else
 652                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 653                                   "'%s'"), buf.buf);
 654         }
 655
 656         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 657                 strbuf_reset(&buf);
 658                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 659                             &buf))
 660                         return -1;
 661                 free(opts->gpg_sign_opt);
 662                 opts->gpg_sign_opt = xstrdup(buf.buf);
 663         }
 664
 665         if (file_exists(state_dir_path("strategy", opts))) {
 666                 strbuf_reset(&buf);
 667                 if (read_one(state_dir_path("strategy", opts), &buf))
 668                         return -1;
 669                 free(opts->strategy);
 670                 opts->strategy = xstrdup(buf.buf);
 671         }
 672
 673         if (file_exists(state_dir_path("strategy_opts", opts))) {
 674                 strbuf_reset(&buf);
 675                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 676                         return -1;
 677                 free(opts->strategy_opts);
 678                 opts->strategy_opts = xstrdup(buf.buf);
 679         }
 680
 681         strbuf_release(&buf);
 682
 683         return 0;
 684 }
 685
 686 static int rebase_write_basic_state(struct rebase_options *opts)
 687 {
 688         write_file(state_dir_path("head-name", opts), "%s",
 689                    opts->head_name ? opts->head_name : "detached HEAD");
 690         write_file(state_dir_path("onto", opts), "%s",
 691                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 692         write_file(state_dir_path("orig-head", opts), "%s",
 693                    oid_to_hex(&opts->orig_head));
 694         if (!(opts->flags & REBASE_NO_QUIET))
 695                 write_file(state_dir_path("quiet", opts), "%s", "");
 696         if (opts->flags & REBASE_VERBOSE)
 697                 write_file(state_dir_path("verbose", opts), "%s", "");
 698         if (opts->strategy)
 699                 write_file(state_dir_path("strategy", opts), "%s",
 700                            opts->strategy);
 701         if (opts->strategy_opts)
 702                 write_file(state_dir_path("strategy_opts", opts), "%s",
 703                            opts->strategy_opts);
 704         if (opts->allow_rerere_autoupdate > 0)
 705                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 706                            "-%s-rerere-autoupdate",
 707                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 708                                 "" : "-no");
 709         if (opts->gpg_sign_opt)
 710                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 711                            opts->gpg_sign_opt);
 712         if (opts->signoff)
 713                 write_file(state_dir_path("signoff", opts), "--signoff");
 714
 715         return 0;
 716 }
 717
 718 static int apply_autostash(struct rebase_options *opts)
 719 {
 720         const char *path = state_dir_path("autostash", opts);
 721         struct strbuf autostash = STRBUF_INIT;
 722         struct child_process stash_apply = CHILD_PROCESS_INIT;
 723
 724         if (!file_exists(path))
 725                 return 0;
 726
 727         if (read_one(path, &autostash))
 728                 return error(_("Could not read '%s'"), path);
 729         /* Ensure that the hash is not mistaken for a number */
 730         strbuf_addstr(&autostash, "^0");
 731         argv_array_pushl(&stash_apply.args,
 732                          "stash", "apply", autostash.buf, NULL);
 733         stash_apply.git_cmd = 1;
 734         stash_apply.no_stderr = stash_apply.no_stdout =
 735                 stash_apply.no_stdin = 1;
 736         if (!run_command(&stash_apply))
 737                 printf(_("Applied autostash.\n"));
 738         else {
 739                 struct argv_array args = ARGV_ARRAY_INIT;
 740                 int res = 0;
 741
 742                 argv_array_pushl(&args,
 743                                  "stash", "store", "-m", "autostash", "-q",
 744                                  autostash.buf, NULL);
 745                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 746                         res = error(_("Cannot store %s"), autostash.buf);
 747                 argv_array_clear(&args);
 748                 strbuf_release(&autostash);
 749                 if (res)
 750                         return res;
 751
 752                 fprintf(stderr,
 753                         _("Applying autostash resulted in conflicts.\n"
 754                           "Your changes are safe in the stash.\n"
 755                           "You can run \"git stash pop\" or \"git stash drop\" "
 756                           "at any time.\n"));
 757         }
 758
 759         strbuf_release(&autostash);
 760         return 0;
 761 }
 762
 763 static int finish_rebase(struct rebase_options *opts)
 764 {
 765         struct strbuf dir = STRBUF_INIT;
 766         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 767         int ret = 0;
 768
 769         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 770         apply_autostash(opts);
 771         close_object_store(the_repository->objects);
 772         /*
 773          * We ignore errors in 'gc --auto', since the
 774          * user should see them.
 775          */
 776         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 777         if (opts->type == REBASE_MERGE) {
 778                 struct replay_opts replay = REPLAY_OPTS_INIT;
 779
 780                 replay.action = REPLAY_INTERACTIVE_REBASE;
 781                 ret = sequencer_remove_state(&replay);
 782         } else {
 783                 strbuf_addstr(&dir, opts->state_dir);
 784                 if (remove_dir_recursively(&dir, 0))
 785                         ret = error(_("could not remove '%s'"),
 786                                     opts->state_dir);
 787                 strbuf_release(&dir);
 788         }
 789
 790         return ret;
 791 }
 792
 793 static struct commit *peel_committish(const char *name)
 794 {
 795         struct object *obj;
 796         struct object_id oid;
 797
 798         if (get_oid(name, &oid))
 799                 return NULL;
 800         obj = parse_object(the_repository, &oid);
 801         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 802 }
 803
 804 static void add_var(struct strbuf *buf, const char *name, const char *value)
 805 {
 806         if (!value)
 807                 strbuf_addf(buf, "unset %s; ", name);
 808         else {
 809                 strbuf_addf(buf, "%s=", name);
 810                 sq_quote_buf(buf, value);
 811                 strbuf_addstr(buf, "; ");
 812         }
 813 }
 814
 815 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 816
 817 #define RESET_HEAD_DETACH (1<<0)
 818 #define RESET_HEAD_HARD (1<<1)
 819 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 820 #define RESET_HEAD_REFS_ONLY (1<<3)
 821 #define RESET_ORIG_HEAD (1<<4)
 822
 823 static int reset_head(struct object_id *oid, const char *action,
 824                       const char *switch_to_branch, unsigned flags,
 825                       const char *reflog_orig_head, const char *reflog_head)
 826 {
 827         unsigned detach_head = flags & RESET_HEAD_DETACH;
 828         unsigned reset_hard = flags & RESET_HEAD_HARD;
 829         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 830         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 831         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 832         struct object_id head_oid;
 833         struct tree_desc desc[2] = { { NULL }, { NULL } };
 834         struct lock_file lock = LOCK_INIT;
 835         struct unpack_trees_options unpack_tree_opts;
 836         struct tree *tree;
 837         const char *reflog_action;
 838         struct strbuf msg = STRBUF_INIT;
 839         size_t prefix_len;
 840         struct object_id *orig = NULL, oid_orig,
 841                 *old_orig = NULL, oid_old_orig;
 842         int ret = 0, nr = 0;
 843
 844         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 845                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 846
 847         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 848                 ret = -1;
 849                 goto leave_reset_head;
 850         }
 851
 852         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 853                 ret = error(_("could not determine HEAD revision"));
 854                 goto leave_reset_head;
 855         }
 856
 857         if (!oid)
 858                 oid = &head_oid;
 859
 860         if (refs_only)
 861                 goto reset_head_refs;
 862
 863         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 864         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 865         unpack_tree_opts.head_idx = 1;
 866         unpack_tree_opts.src_index = the_repository->index;
 867         unpack_tree_opts.dst_index = the_repository->index;
 868         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 869         unpack_tree_opts.update = 1;
 870         unpack_tree_opts.merge = 1;
 871         if (!detach_head)
 872                 unpack_tree_opts.reset = 1;
 873
 874         if (repo_read_index_unmerged(the_repository) < 0) {
 875                 ret = error(_("could not read index"));
 876                 goto leave_reset_head;
 877         }
 878
 879         if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 880                 ret = error(_("failed to find tree of %s"),
 881                             oid_to_hex(&head_oid));
 882                 goto leave_reset_head;
 883         }
 884
 885         if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 886                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 887                 goto leave_reset_head;
 888         }
 889
 890         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 891                 ret = -1;
 892                 goto leave_reset_head;
 893         }
 894
 895         tree = parse_tree_indirect(oid);
 896         prime_cache_tree(the_repository, the_repository->index, tree);
 897
 898         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 899                 ret = error(_("could not write index"));
 900                 goto leave_reset_head;
 901         }
 902
 903 reset_head_refs:
 904         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 905         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 906         prefix_len = msg.len;
 907
 908         if (update_orig_head) {
 909                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 910                         old_orig = &oid_old_orig;
 911                 if (!get_oid("HEAD", &oid_orig)) {
 912                         orig = &oid_orig;
 913                         if (!reflog_orig_head) {
 914                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 915                                 reflog_orig_head = msg.buf;
 916                         }
 917                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 918                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 919                 } else if (old_orig)
 920                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 921         }
 922
 923         if (!reflog_head) {
 924                 strbuf_setlen(&msg, prefix_len);
 925                 strbuf_addstr(&msg, "updating HEAD");
 926                 reflog_head = msg.buf;
 927         }
 928         if (!switch_to_branch)
 929                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 930                                  detach_head ? REF_NO_DEREF : 0,
 931                                  UPDATE_REFS_MSG_ON_ERR);
 932         else {
 933                 ret = update_ref(reflog_head, switch_to_branch, oid,
 934                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 935                 if (!ret)
 936                         ret = create_symref("HEAD", switch_to_branch,
 937                                             reflog_head);
 938         }
 939         if (run_hook)
 940                 run_hook_le(NULL, "post-checkout",
 941                             oid_to_hex(orig ? orig : &null_oid),
 942                             oid_to_hex(oid), "1", NULL);
 943
 944 leave_reset_head:
 945         strbuf_release(&msg);
 946         rollback_lock_file(&lock);
 947         while (nr)
 948                 free((void *)desc[--nr].buffer);
 949         return ret;
 950 }
 951
 952 static int move_to_original_branch(struct rebase_options *opts)
 953 {
 954         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 955         int ret;
 956
 957         if (!opts->head_name)
 958                 return 0; /* nothing to move back to */
 959
 960         if (!opts->onto)
 961                 BUG("move_to_original_branch without onto");
 962
 963         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 964                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 965         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 966                     opts->head_name);
 967         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 968                          orig_head_reflog.buf, head_reflog.buf);
 969
 970         strbuf_release(&orig_head_reflog);
 971         strbuf_release(&head_reflog);
 972         return ret;
 973 }
 974
 975 static const char *resolvemsg =
 976 N_("Resolve all conflicts manually, mark them as resolved with\n"
 977 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 978 "You can instead skip this commit: run \"git rebase --skip\".\n"
 979 "To abort and get back to the state before \"git rebase\", run "
 980 "\"git rebase --abort\".");
 981
 982 static int run_am(struct rebase_options *opts)
 983 {
 984         struct child_process am = CHILD_PROCESS_INIT;
 985         struct child_process format_patch = CHILD_PROCESS_INIT;
 986         struct strbuf revisions = STRBUF_INIT;
 987         int status;
 988         char *rebased_patches;
 989
 990         am.git_cmd = 1;
 991         argv_array_push(&am.args, "am");
 992
 993         if (opts->action && !strcmp("continue", opts->action)) {
 994                 argv_array_push(&am.args, "--resolved");
 995                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 996                 if (opts->gpg_sign_opt)
 997                         argv_array_push(&am.args, opts->gpg_sign_opt);
 998                 status = run_command(&am);
 999                 if (status)
1000                         return status;
1001
1002                 return move_to_original_branch(opts);
1003         }
1004         if (opts->action && !strcmp("skip", opts->action)) {
1005                 argv_array_push(&am.args, "--skip");
1006                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1007                 status = run_command(&am);
1008                 if (status)
1009                         return status;
1010
1011                 return move_to_original_branch(opts);
1012         }
1013         if (opts->action && !strcmp("show-current-patch", opts->action)) {
1014                 argv_array_push(&am.args, "--show-current-patch");
1015                 return run_command(&am);
1016         }
1017
1018         strbuf_addf(&revisions, "%s...%s",
1019                     oid_to_hex(opts->root ?
1020                                /* this is now equivalent to !opts->upstream */
1021                                &opts->onto->object.oid :
1022                                &opts->upstream->object.oid),
1023                     oid_to_hex(&opts->orig_head));
1024
1025         rebased_patches = xstrdup(git_path("rebased-patches"));
1026         format_patch.out = open(rebased_patches,
1027                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1028         if (format_patch.out < 0) {
1029                 status = error_errno(_("could not open '%s' for writing"),
1030                                      rebased_patches);
1031                 free(rebased_patches);
1032                 argv_array_clear(&am.args);
1033                 return status;
1034         }
1035
1036         format_patch.git_cmd = 1;
1037         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1038                          "--full-index", "--cherry-pick", "--right-only",
1039                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1040                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
1041                          "--no-base", NULL);
1042         if (opts->git_format_patch_opt.len)
1043                 argv_array_split(&format_patch.args,
1044                                  opts->git_format_patch_opt.buf);
1045         argv_array_push(&format_patch.args, revisions.buf);
1046         if (opts->restrict_revision)
1047                 argv_array_pushf(&format_patch.args, "^%s",
1048                                  oid_to_hex(&opts->restrict_revision->object.oid));
1049
1050         status = run_command(&format_patch);
1051         if (status) {
1052                 unlink(rebased_patches);
1053                 free(rebased_patches);
1054                 argv_array_clear(&am.args);
1055
1056                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1057                            "HEAD", NULL);
1058                 error(_("\ngit encountered an error while preparing the "
1059                         "patches to replay\n"
1060                         "these revisions:\n"
1061                         "\n    %s\n\n"
1062                         "As a result, git cannot rebase them."),
1063                       opts->revisions);
1064
1065                 strbuf_release(&revisions);
1066                 return status;
1067         }
1068         strbuf_release(&revisions);
1069
1070         am.in = open(rebased_patches, O_RDONLY);
1071         if (am.in < 0) {
1072                 status = error_errno(_("could not open '%s' for reading"),
1073                                      rebased_patches);
1074                 free(rebased_patches);
1075                 argv_array_clear(&am.args);
1076                 return status;
1077         }
1078
1079         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1080         argv_array_push(&am.args, "--rebasing");
1081         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1082         argv_array_push(&am.args, "--patch-format=mboxrd");
1083         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1084                 argv_array_push(&am.args, "--rerere-autoupdate");
1085         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1086                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1087         if (opts->gpg_sign_opt)
1088                 argv_array_push(&am.args, opts->gpg_sign_opt);
1089         status = run_command(&am);
1090         unlink(rebased_patches);
1091         free(rebased_patches);
1092
1093         if (!status) {
1094                 return move_to_original_branch(opts);
1095         }
1096
1097         if (is_directory(opts->state_dir))
1098                 rebase_write_basic_state(opts);
1099
1100         return status;
1101 }
1102
1103 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1104 {
1105         const char *argv[] = { NULL, NULL };
1106         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1107         int status;
1108         const char *backend, *backend_func;
1109
1110         if (opts->type == REBASE_MERGE) {
1111                 /* Run sequencer-based rebase */
1112                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1113                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1114                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1115                         opts->autosquash = 0;
1116                 }
1117                 if (opts->gpg_sign_opt) {
1118                         /* remove the leading "-S" */
1119                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1120                         free(opts->gpg_sign_opt);
1121                         opts->gpg_sign_opt = tmp;
1122                 }
1123
1124                 status = run_sequencer_rebase(opts, action);
1125                 goto finished_rebase;
1126         }
1127
1128         if (opts->type == REBASE_APPLY) {
1129                 status = run_am(opts);
1130                 goto finished_rebase;
1131         }
1132
1133         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1134         add_var(&script_snippet, "state_dir", opts->state_dir);
1135
1136         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1137         add_var(&script_snippet, "upstream", opts->upstream ?
1138                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1139         add_var(&script_snippet, "head_name",
1140                 opts->head_name ? opts->head_name : "detached HEAD");
1141         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1142         add_var(&script_snippet, "onto", opts->onto ?
1143                 oid_to_hex(&opts->onto->object.oid) : NULL);
1144         add_var(&script_snippet, "onto_name", opts->onto_name);
1145         add_var(&script_snippet, "revisions", opts->revisions);
1146         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1147                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1148         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1149         add_var(&script_snippet, "git_am_opt", buf.buf);
1150         strbuf_release(&buf);
1151         add_var(&script_snippet, "verbose",
1152                 opts->flags & REBASE_VERBOSE ? "t" : "");
1153         add_var(&script_snippet, "diffstat",
1154                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1155         add_var(&script_snippet, "force_rebase",
1156                 opts->flags & REBASE_FORCE ? "t" : "");
1157         if (opts->switch_to)
1158                 add_var(&script_snippet, "switch_to", opts->switch_to);
1159         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1160         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1161         add_var(&script_snippet, "allow_rerere_autoupdate",
1162                 opts->allow_rerere_autoupdate ?
1163                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1164                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1165         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1166         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1167         add_var(&script_snippet, "cmd", opts->cmd);
1168         add_var(&script_snippet, "allow_empty_message",
1169                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1170         add_var(&script_snippet, "rebase_merges",
1171                 opts->rebase_merges ? "t" : "");
1172         add_var(&script_snippet, "rebase_cousins",
1173                 opts->rebase_cousins ? "t" : "");
1174         add_var(&script_snippet, "strategy", opts->strategy);
1175         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1176         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1177         add_var(&script_snippet, "squash_onto",
1178                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1179         add_var(&script_snippet, "git_format_patch_opt",
1180                 opts->git_format_patch_opt.buf);
1181
1182         if (is_merge(opts) &&
1183             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1184                 strbuf_addstr(&script_snippet,
1185                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1186                 opts->autosquash = 0;
1187         }
1188
1189         switch (opts->type) {
1190         case REBASE_PRESERVE_MERGES:
1191                 backend = "git-rebase--preserve-merges";
1192                 backend_func = "git_rebase__preserve_merges";
1193                 break;
1194         default:
1195                 BUG("Unhandled rebase type %d", opts->type);
1196                 break;
1197         }
1198
1199         strbuf_addf(&script_snippet,
1200                     ". git-sh-setup && . %s && %s", backend, backend_func);
1201         argv[0] = script_snippet.buf;
1202
1203         status = run_command_v_opt(argv, RUN_USING_SHELL);
1204 finished_rebase:
1205         if (opts->dont_finish_rebase)
1206                 ; /* do nothing */
1207         else if (opts->type == REBASE_MERGE)
1208                 ; /* merge backend cleans up after itself */
1209         else if (status == 0) {
1210                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1211                         finish_rebase(opts);
1212         } else if (status == 2) {
1213                 struct strbuf dir = STRBUF_INIT;
1214
1215                 apply_autostash(opts);
1216                 strbuf_addstr(&dir, opts->state_dir);
1217                 remove_dir_recursively(&dir, 0);
1218                 strbuf_release(&dir);
1219                 die("Nothing to do");
1220         }
1221
1222         strbuf_release(&script_snippet);
1223
1224         return status ? -1 : 0;
1225 }
1226
1227 static int rebase_config(const char *var, const char *value, void *data)
1228 {
1229         struct rebase_options *opts = data;
1230
1231         if (!strcmp(var, "rebase.stat")) {
1232                 if (git_config_bool(var, value))
1233                         opts->flags |= REBASE_DIFFSTAT;
1234                 else
1235                         opts->flags &= ~REBASE_DIFFSTAT;
1236                 return 0;
1237         }
1238
1239         if (!strcmp(var, "rebase.autosquash")) {
1240                 opts->autosquash = git_config_bool(var, value);
1241                 return 0;
1242         }
1243
1244         if (!strcmp(var, "commit.gpgsign")) {
1245                 free(opts->gpg_sign_opt);
1246                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1247                         xstrdup("-S") : NULL;
1248                 return 0;
1249         }
1250
1251         if (!strcmp(var, "rebase.autostash")) {
1252                 opts->autostash = git_config_bool(var, value);
1253                 return 0;
1254         }
1255
1256         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1257                 opts->reschedule_failed_exec = git_config_bool(var, value);
1258                 return 0;
1259         }
1260
1261         if (!strcmp(var, "rebase.usebuiltin")) {
1262                 opts->use_legacy_rebase = !git_config_bool(var, value);
1263                 return 0;
1264         }
1265
1266         if (!strcmp(var, "rebase.backend")) {
1267                 return git_config_string(&opts->default_backend, var, value);
1268         }
1269
1270         return git_default_config(var, value, data);
1271 }
1272
1273 /*
1274  * Determines whether the commits in from..to are linear, i.e. contain
1275  * no merge commits. This function *expects* `from` to be an ancestor of
1276  * `to`.
1277  */
1278 static int is_linear_history(struct commit *from, struct commit *to)
1279 {
1280         while (to && to != from) {
1281                 parse_commit(to);
1282                 if (!to->parents)
1283                         return 1;
1284                 if (to->parents->next)
1285                         return 0;
1286                 to = to->parents->item;
1287         }
1288         return 1;
1289 }
1290
1291 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1292                             struct commit *restrict_revision,
1293                             struct object_id *head_oid, struct object_id *merge_base)
1294 {
1295         struct commit *head = lookup_commit(the_repository, head_oid);
1296         struct commit_list *merge_bases = NULL;
1297         int res = 0;
1298
1299         if (!head)
1300                 goto done;
1301
1302         merge_bases = get_merge_bases(onto, head);
1303         if (!merge_bases || merge_bases->next) {
1304                 oidcpy(merge_base, &null_oid);
1305                 goto done;
1306         }
1307
1308         oidcpy(merge_base, &merge_bases->item->object.oid);
1309         if (!oideq(merge_base, &onto->object.oid))
1310                 goto done;
1311
1312         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1313                 goto done;
1314
1315         if (!upstream)
1316                 goto done;
1317
1318         free_commit_list(merge_bases);
1319         merge_bases = get_merge_bases(upstream, head);
1320         if (!merge_bases || merge_bases->next)
1321                 goto done;
1322
1323         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1324                 goto done;
1325
1326         res = 1;
1327
1328 done:
1329         free_commit_list(merge_bases);
1330         return res && is_linear_history(onto, head);
1331 }
1332
1333 static int parse_opt_am(const struct option *opt, const char *arg, int unset)
1334 {
1335         struct rebase_options *opts = opt->value;
1336
1337         BUG_ON_OPT_NEG(unset);
1338         BUG_ON_OPT_ARG(arg);
1339
1340         opts->type = REBASE_APPLY;
1341
1342         return 0;
1343 }
1344
1345 /* -i followed by -m is still -i */
1346 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1347 {
1348         struct rebase_options *opts = opt->value;
1349
1350         BUG_ON_OPT_NEG(unset);
1351         BUG_ON_OPT_ARG(arg);
1352
1353         if (!is_merge(opts))
1354                 opts->type = REBASE_MERGE;
1355
1356         return 0;
1357 }
1358
1359 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1360 static int parse_opt_interactive(const struct option *opt, const char *arg,
1361                                  int unset)
1362 {
1363         struct rebase_options *opts = opt->value;
1364
1365         BUG_ON_OPT_NEG(unset);
1366         BUG_ON_OPT_ARG(arg);
1367
1368         opts->type = REBASE_MERGE;
1369         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1370
1371         return 0;
1372 }
1373
1374 static enum empty_type parse_empty_value(const char *value)
1375 {
1376         if (!strcasecmp(value, "drop"))
1377                 return EMPTY_DROP;
1378         else if (!strcasecmp(value, "keep"))
1379                 return EMPTY_KEEP;
1380         else if (!strcasecmp(value, "ask"))
1381                 return EMPTY_ASK;
1382
1383         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
1384 }
1385
1386 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
1387 {
1388         struct rebase_options *options = opt->value;
1389         enum empty_type value = parse_empty_value(arg);
1390
1391         BUG_ON_OPT_NEG(unset);
1392
1393         options->empty = value;
1394         return 0;
1395 }
1396
1397 static void NORETURN error_on_missing_default_upstream(void)
1398 {
1399         struct branch *current_branch = branch_get(NULL);
1400
1401         printf(_("%s\n"
1402                  "Please specify which branch you want to rebase against.\n"
1403                  "See git-rebase(1) for details.\n"
1404                  "\n"
1405                  "    git rebase '<branch>'\n"
1406                  "\n"),
1407                 current_branch ? _("There is no tracking information for "
1408                         "the current branch.") :
1409                         _("You are not currently on a branch."));
1410
1411         if (current_branch) {
1412                 const char *remote = current_branch->remote_name;
1413
1414                 if (!remote)
1415                         remote = _("<remote>");
1416
1417                 printf(_("If you wish to set tracking information for this "
1418                          "branch you can do so with:\n"
1419                          "\n"
1420                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1421                          "\n"),
1422                        remote, current_branch->name);
1423         }
1424         exit(1);
1425 }
1426
1427 static void set_reflog_action(struct rebase_options *options)
1428 {
1429         const char *env;
1430         struct strbuf buf = STRBUF_INIT;
1431
1432         if (!is_merge(options))
1433                 return;
1434
1435         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1436         if (env && strcmp("rebase", env))
1437                 return; /* only override it if it is "rebase" */
1438
1439         strbuf_addf(&buf, "rebase (%s)", options->action);
1440         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1441         strbuf_release(&buf);
1442 }
1443
1444 static int check_exec_cmd(const char *cmd)
1445 {
1446         if (strchr(cmd, '\n'))
1447                 return error(_("exec commands cannot contain newlines"));
1448
1449         /* Does the command consist purely of whitespace? */
1450         if (!cmd[strspn(cmd, " \t\r\f\v")])
1451                 return error(_("empty exec command"));
1452
1453         return 0;
1454 }
1455
1456
1457 int cmd_rebase(int argc, const char **argv, const char *prefix)
1458 {
1459         struct rebase_options options = REBASE_OPTIONS_INIT;
1460         const char *branch_name;
1461         int ret, flags, total_argc, in_progress = 0;
1462         int keep_base = 0;
1463         int ok_to_skip_pre_rebase = 0;
1464         struct strbuf msg = STRBUF_INIT;
1465         struct strbuf revisions = STRBUF_INIT;
1466         struct strbuf buf = STRBUF_INIT;
1467         struct object_id merge_base;
1468         enum action action = ACTION_NONE;
1469         const char *gpg_sign = NULL;
1470         struct string_list exec = STRING_LIST_INIT_NODUP;
1471         const char *rebase_merges = NULL;
1472         int fork_point = -1;
1473         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1474         struct object_id squash_onto;
1475         char *squash_onto_name = NULL;
1476         int reschedule_failed_exec = -1;
1477         int allow_preemptive_ff = 1;
1478         struct option builtin_rebase_options[] = {
1479                 OPT_STRING(0, "onto", &options.onto_name,
1480                            N_("revision"),
1481                            N_("rebase onto given branch instead of upstream")),
1482                 OPT_BOOL(0, "keep-base", &keep_base,
1483                          N_("use the merge-base of upstream and branch as the current base")),
1484                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1485                          N_("allow pre-rebase hook to run")),
1486                 OPT_NEGBIT('q', "quiet", &options.flags,
1487                            N_("be quiet. implies --no-stat"),
1488                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1489                 OPT_BIT('v', "verbose", &options.flags,
1490                         N_("display a diffstat of what changed upstream"),
1491                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1492                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1493                         N_("do not show diffstat of what changed upstream"),
1494                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1495                 OPT_BOOL(0, "signoff", &options.signoff,
1496                          N_("add a Signed-off-by: line to each commit")),
1497                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1498                                   NULL, N_("passed to 'git am'"),
1499                                   PARSE_OPT_NOARG),
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_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1508                                   N_("action"), N_("passed to 'git apply'"), 0),
1509                 OPT_BIT('f', "force-rebase", &options.flags,
1510                         N_("cherry-pick all commits, even if unchanged"),
1511                         REBASE_FORCE),
1512                 OPT_BIT(0, "no-ff", &options.flags,
1513                         N_("cherry-pick all commits, even if unchanged"),
1514                         REBASE_FORCE),
1515                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1516                             ACTION_CONTINUE),
1517                 OPT_CMDMODE(0, "skip", &action,
1518                             N_("skip current patch and continue"), ACTION_SKIP),
1519                 OPT_CMDMODE(0, "abort", &action,
1520                             N_("abort and check out the original branch"),
1521                             ACTION_ABORT),
1522                 OPT_CMDMODE(0, "quit", &action,
1523                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1524                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1525                             "during an interactive rebase"), ACTION_EDIT_TODO),
1526                 OPT_CMDMODE(0, "show-current-patch", &action,
1527                             N_("show the patch file being applied or merged"),
1528                             ACTION_SHOW_CURRENT_PATCH),
1529                 { OPTION_CALLBACK, 0, "apply", &options, NULL,
1530                         N_("use apply strategies to rebase"),
1531                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1532                         parse_opt_am },
1533                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1534                         N_("use merging strategies to rebase"),
1535                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1536                         parse_opt_merge },
1537                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1538                         N_("let the user edit the list of commits to rebase"),
1539                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1540                         parse_opt_interactive },
1541                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1542                               N_("(DEPRECATED) try to recreate merges instead of "
1543                                  "ignoring them"),
1544                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1545                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1546                 OPT_CALLBACK_F(0, "empty", &options, "{drop,keep,ask}",
1547                                N_("how to handle commits that become empty"),
1548                                PARSE_OPT_NONEG, parse_opt_empty),
1549                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
1550                         N_("(DEPRECATED) keep empty commits"),
1551                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1552                         parse_opt_keep_empty },
1553                 OPT_BOOL(0, "autosquash", &options.autosquash,
1554                          N_("move commits that begin with "
1555                             "squash!/fixup! under -i")),
1556                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1557                         N_("GPG-sign commits"),
1558                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1559                 OPT_BOOL(0, "autostash", &options.autostash,
1560                          N_("automatically stash/stash pop before and after")),
1561                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1562                                 N_("add exec lines after each commit of the "
1563                                    "editable list")),
1564                 OPT_BOOL_F(0, "allow-empty-message",
1565                            &options.allow_empty_message,
1566                            N_("allow rebasing commits with empty messages"),
1567                            PARSE_OPT_HIDDEN),
1568                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1569                         N_("mode"),
1570                         N_("try to rebase merges instead of skipping them"),
1571                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1572                 OPT_BOOL(0, "fork-point", &fork_point,
1573                          N_("use 'merge-base --fork-point' to refine upstream")),
1574                 OPT_STRING('s', "strategy", &options.strategy,
1575                            N_("strategy"), N_("use the given merge strategy")),
1576                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1577                                 N_("option"),
1578                                 N_("pass the argument through to the merge "
1579                                    "strategy")),
1580                 OPT_BOOL(0, "root", &options.root,
1581                          N_("rebase all reachable commits up to the root(s)")),
1582                 OPT_BOOL(0, "reschedule-failed-exec",
1583                          &reschedule_failed_exec,
1584                          N_("automatically re-schedule any `exec` that fails")),
1585                 OPT_END(),
1586         };
1587         int i;
1588
1589         if (argc == 2 && !strcmp(argv[1], "-h"))
1590                 usage_with_options(builtin_rebase_usage,
1591                                    builtin_rebase_options);
1592
1593         options.allow_empty_message = 1;
1594         git_config(rebase_config, &options);
1595
1596         if (options.use_legacy_rebase ||
1597             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1598                 warning(_("the rebase.useBuiltin support has been removed!\n"
1599                           "See its entry in 'git help config' for details."));
1600
1601         strbuf_reset(&buf);
1602         strbuf_addf(&buf, "%s/applying", apply_dir());
1603         if(file_exists(buf.buf))
1604                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1605
1606         if (is_directory(apply_dir())) {
1607                 options.type = REBASE_APPLY;
1608                 options.state_dir = apply_dir();
1609         } else if (is_directory(merge_dir())) {
1610                 strbuf_reset(&buf);
1611                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1612                 if (is_directory(buf.buf)) {
1613                         options.type = REBASE_PRESERVE_MERGES;
1614                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1615                 } else {
1616                         strbuf_reset(&buf);
1617                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1618                         if(file_exists(buf.buf)) {
1619                                 options.type = REBASE_MERGE;
1620                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1621                         } else
1622                                 options.type = REBASE_MERGE;
1623                 }
1624                 options.state_dir = merge_dir();
1625         }
1626
1627         if (options.type != REBASE_UNSPECIFIED)
1628                 in_progress = 1;
1629
1630         total_argc = argc;
1631         argc = parse_options(argc, argv, prefix,
1632                              builtin_rebase_options,
1633                              builtin_rebase_usage, 0);
1634
1635         if (action != ACTION_NONE && total_argc != 2) {
1636                 usage_with_options(builtin_rebase_usage,
1637                                    builtin_rebase_options);
1638         }
1639
1640         if (argc > 2)
1641                 usage_with_options(builtin_rebase_usage,
1642                                    builtin_rebase_options);
1643
1644         if (options.type == REBASE_PRESERVE_MERGES)
1645                 warning(_("git rebase --preserve-merges is deprecated. "
1646                           "Use --rebase-merges instead."));
1647
1648         if (keep_base) {
1649                 if (options.onto_name)
1650                         die(_("cannot combine '--keep-base' with '--onto'"));
1651                 if (options.root)
1652                         die(_("cannot combine '--keep-base' with '--root'"));
1653         }
1654
1655         if (action != ACTION_NONE && !in_progress)
1656                 die(_("No rebase in progress?"));
1657         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1658
1659         if (action == ACTION_EDIT_TODO && !is_merge(&options))
1660                 die(_("The --edit-todo action can only be used during "
1661                       "interactive rebase."));
1662
1663         if (trace2_is_enabled()) {
1664                 if (is_merge(&options))
1665                         trace2_cmd_mode("interactive");
1666                 else if (exec.nr)
1667                         trace2_cmd_mode("interactive-exec");
1668                 else
1669                         trace2_cmd_mode(action_names[action]);
1670         }
1671
1672         switch (action) {
1673         case ACTION_CONTINUE: {
1674                 struct object_id head;
1675                 struct lock_file lock_file = LOCK_INIT;
1676                 int fd;
1677
1678                 options.action = "continue";
1679                 set_reflog_action(&options);
1680
1681                 /* Sanity check */
1682                 if (get_oid("HEAD", &head))
1683                         die(_("Cannot read HEAD"));
1684
1685                 fd = hold_locked_index(&lock_file, 0);
1686                 if (repo_read_index(the_repository) < 0)
1687                         die(_("could not read index"));
1688                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1689                               NULL);
1690                 if (0 <= fd)
1691                         repo_update_index_if_able(the_repository, &lock_file);
1692                 rollback_lock_file(&lock_file);
1693
1694                 if (has_unstaged_changes(the_repository, 1)) {
1695                         puts(_("You must edit all merge conflicts and then\n"
1696                                "mark them as resolved using git add"));
1697                         exit(1);
1698                 }
1699                 if (read_basic_state(&options))
1700                         exit(1);
1701                 goto run_rebase;
1702         }
1703         case ACTION_SKIP: {
1704                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1705
1706                 options.action = "skip";
1707                 set_reflog_action(&options);
1708
1709                 rerere_clear(the_repository, &merge_rr);
1710                 string_list_clear(&merge_rr, 1);
1711
1712                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1713                                NULL, NULL) < 0)
1714                         die(_("could not discard worktree changes"));
1715                 remove_branch_state(the_repository, 0);
1716                 if (read_basic_state(&options))
1717                         exit(1);
1718                 goto run_rebase;
1719         }
1720         case ACTION_ABORT: {
1721                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1722                 options.action = "abort";
1723                 set_reflog_action(&options);
1724
1725                 rerere_clear(the_repository, &merge_rr);
1726                 string_list_clear(&merge_rr, 1);
1727
1728                 if (read_basic_state(&options))
1729                         exit(1);
1730                 if (reset_head(&options.orig_head, "reset",
1731                                options.head_name, RESET_HEAD_HARD,
1732                                NULL, NULL) < 0)
1733                         die(_("could not move back to %s"),
1734                             oid_to_hex(&options.orig_head));
1735                 remove_branch_state(the_repository, 0);
1736                 ret = !!finish_rebase(&options);
1737                 goto cleanup;
1738         }
1739         case ACTION_QUIT: {
1740                 if (options.type == REBASE_MERGE) {
1741                         struct replay_opts replay = REPLAY_OPTS_INIT;
1742
1743                         replay.action = REPLAY_INTERACTIVE_REBASE;
1744                         ret = !!sequencer_remove_state(&replay);
1745                 } else {
1746                         strbuf_reset(&buf);
1747                         strbuf_addstr(&buf, options.state_dir);
1748                         ret = !!remove_dir_recursively(&buf, 0);
1749                         if (ret)
1750                                 error(_("could not remove '%s'"),
1751                                        options.state_dir);
1752                 }
1753                 goto cleanup;
1754         }
1755         case ACTION_EDIT_TODO:
1756                 options.action = "edit-todo";
1757                 options.dont_finish_rebase = 1;
1758                 goto run_rebase;
1759         case ACTION_SHOW_CURRENT_PATCH:
1760                 options.action = "show-current-patch";
1761                 options.dont_finish_rebase = 1;
1762                 goto run_rebase;
1763         case ACTION_NONE:
1764                 break;
1765         default:
1766                 BUG("action: %d", action);
1767         }
1768
1769         /* Make sure no rebase is in progress */
1770         if (in_progress) {
1771                 const char *last_slash = strrchr(options.state_dir, '/');
1772                 const char *state_dir_base =
1773                         last_slash ? last_slash + 1 : options.state_dir;
1774                 const char *cmd_live_rebase =
1775                         "git rebase (--continue | --abort | --skip)";
1776                 strbuf_reset(&buf);
1777                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1778                 die(_("It seems that there is already a %s directory, and\n"
1779                       "I wonder if you are in the middle of another rebase.  "
1780                       "If that is the\n"
1781                       "case, please try\n\t%s\n"
1782                       "If that is not the case, please\n\t%s\n"
1783                       "and run me again.  I am stopping in case you still "
1784                       "have something\n"
1785                       "valuable there.\n"),
1786                     state_dir_base, cmd_live_rebase, buf.buf);
1787         }
1788
1789         if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
1790             (action != ACTION_NONE) ||
1791             (exec.nr > 0) ||
1792             options.autosquash) {
1793                 allow_preemptive_ff = 0;
1794         }
1795
1796         for (i = 0; i < options.git_am_opts.argc; i++) {
1797                 const char *option = options.git_am_opts.argv[i], *p;
1798                 if (!strcmp(option, "--committer-date-is-author-date") ||
1799                     !strcmp(option, "--ignore-date") ||
1800                     !strcmp(option, "--whitespace=fix") ||
1801                     !strcmp(option, "--whitespace=strip"))
1802                         allow_preemptive_ff = 0;
1803                 else if (skip_prefix(option, "-C", &p)) {
1804                         while (*p)
1805                                 if (!isdigit(*(p++)))
1806                                         die(_("switch `C' expects a "
1807                                               "numerical value"));
1808                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1809                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1810                             strcmp(p, "error") && strcmp(p, "error-all"))
1811                                 die("Invalid whitespace option: '%s'", p);
1812                 }
1813         }
1814
1815         for (i = 0; i < exec.nr; i++)
1816                 if (check_exec_cmd(exec.items[i].string))
1817                         exit(1);
1818
1819         if (!(options.flags & REBASE_NO_QUIET))
1820                 argv_array_push(&options.git_am_opts, "-q");
1821
1822         if (options.empty != EMPTY_UNSPECIFIED)
1823                 imply_merge(&options, "--empty");
1824
1825         if (gpg_sign) {
1826                 free(options.gpg_sign_opt);
1827                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1828         }
1829
1830         if (exec.nr) {
1831                 int i;
1832
1833                 imply_merge(&options, "--exec");
1834
1835                 strbuf_reset(&buf);
1836                 for (i = 0; i < exec.nr; i++)
1837                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1838                 options.cmd = xstrdup(buf.buf);
1839         }
1840
1841         if (rebase_merges) {
1842                 if (!*rebase_merges)
1843                         ; /* default mode; do nothing */
1844                 else if (!strcmp("rebase-cousins", rebase_merges))
1845                         options.rebase_cousins = 1;
1846                 else if (strcmp("no-rebase-cousins", rebase_merges))
1847                         die(_("Unknown mode: %s"), rebase_merges);
1848                 options.rebase_merges = 1;
1849                 imply_merge(&options, "--rebase-merges");
1850         }
1851
1852         if (strategy_options.nr) {
1853                 int i;
1854
1855                 if (!options.strategy)
1856                         options.strategy = "recursive";
1857
1858                 strbuf_reset(&buf);
1859                 for (i = 0; i < strategy_options.nr; i++)
1860                         strbuf_addf(&buf, " --%s",
1861                                     strategy_options.items[i].string);
1862                 options.strategy_opts = xstrdup(buf.buf);
1863         }
1864
1865         if (options.strategy) {
1866                 options.strategy = xstrdup(options.strategy);
1867                 switch (options.type) {
1868                 case REBASE_APPLY:
1869                         die(_("--strategy requires --merge or --interactive"));
1870                 case REBASE_MERGE:
1871                 case REBASE_PRESERVE_MERGES:
1872                         /* compatible */
1873                         break;
1874                 case REBASE_UNSPECIFIED:
1875                         options.type = REBASE_MERGE;
1876                         break;
1877                 default:
1878                         BUG("unhandled rebase type (%d)", options.type);
1879                 }
1880         }
1881
1882         if (options.type == REBASE_MERGE)
1883                 imply_merge(&options, "--merge");
1884
1885         if (options.root && !options.onto_name)
1886                 imply_merge(&options, "--root without --onto");
1887
1888         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1889                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1890
1891         if (options.git_am_opts.argc || options.type == REBASE_APPLY) {
1892                 /* all am options except -q are compatible only with --apply */
1893                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1894                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1895                                 break;
1896
1897                 if (i >= 0) {
1898                         if (is_merge(&options))
1899                                 die(_("cannot combine apply options with "
1900                                       "merge options"));
1901                         else
1902                                 options.type = REBASE_APPLY;
1903                 }
1904         }
1905
1906         if (options.type == REBASE_UNSPECIFIED) {
1907                 if (!strcmp(options.default_backend, "merge"))
1908                         imply_merge(&options, "--merge");
1909                 else if (!strcmp(options.default_backend, "apply"))
1910                         options.type = REBASE_APPLY;
1911                 else
1912                         die(_("Unknown rebase backend: %s"),
1913                             options.default_backend);
1914         }
1915
1916         switch (options.type) {
1917         case REBASE_MERGE:
1918         case REBASE_PRESERVE_MERGES:
1919                 options.state_dir = merge_dir();
1920                 break;
1921         case REBASE_APPLY:
1922                 options.state_dir = apply_dir();
1923                 break;
1924         default:
1925                 BUG("options.type was just set above; should be unreachable.");
1926         }
1927
1928         if (options.empty == EMPTY_UNSPECIFIED) {
1929                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1930                         options.empty = EMPTY_ASK;
1931                 else if (exec.nr > 0)
1932                         options.empty = EMPTY_KEEP;
1933                 else
1934                         options.empty = EMPTY_DROP;
1935         }
1936         if (reschedule_failed_exec > 0 && !is_merge(&options))
1937                 die(_("--reschedule-failed-exec requires "
1938                       "--exec or --interactive"));
1939         if (reschedule_failed_exec >= 0)
1940                 options.reschedule_failed_exec = reschedule_failed_exec;
1941
1942         if (options.signoff) {
1943                 if (options.type == REBASE_PRESERVE_MERGES)
1944                         die("cannot combine '--signoff' with "
1945                             "'--preserve-merges'");
1946                 argv_array_push(&options.git_am_opts, "--signoff");
1947                 options.flags |= REBASE_FORCE;
1948         }
1949
1950         if (options.type == REBASE_PRESERVE_MERGES) {
1951                 /*
1952                  * Note: incompatibility with --signoff handled in signoff block above
1953                  * Note: incompatibility with --interactive is just a strong warning;
1954                  *       git-rebase.txt caveats with "unless you know what you are doing"
1955                  */
1956                 if (options.rebase_merges)
1957                         die(_("cannot combine '--preserve-merges' with "
1958                               "'--rebase-merges'"));
1959
1960                 if (options.reschedule_failed_exec)
1961                         die(_("error: cannot combine '--preserve-merges' with "
1962                               "'--reschedule-failed-exec'"));
1963         }
1964
1965         if (!options.root) {
1966                 if (argc < 1) {
1967                         struct branch *branch;
1968
1969                         branch = branch_get(NULL);
1970                         options.upstream_name = branch_get_upstream(branch,
1971                                                                     NULL);
1972                         if (!options.upstream_name)
1973                                 error_on_missing_default_upstream();
1974                         if (fork_point < 0)
1975                                 fork_point = 1;
1976                 } else {
1977                         options.upstream_name = argv[0];
1978                         argc--;
1979                         argv++;
1980                         if (!strcmp(options.upstream_name, "-"))
1981                                 options.upstream_name = "@{-1}";
1982                 }
1983                 options.upstream = peel_committish(options.upstream_name);
1984                 if (!options.upstream)
1985                         die(_("invalid upstream '%s'"), options.upstream_name);
1986                 options.upstream_arg = options.upstream_name;
1987         } else {
1988                 if (!options.onto_name) {
1989                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1990                                         &squash_onto, NULL, NULL) < 0)
1991                                 die(_("Could not create new root commit"));
1992                         options.squash_onto = &squash_onto;
1993                         options.onto_name = squash_onto_name =
1994                                 xstrdup(oid_to_hex(&squash_onto));
1995                 } else
1996                         options.root_with_onto = 1;
1997
1998                 options.upstream_name = NULL;
1999                 options.upstream = NULL;
2000                 if (argc > 1)
2001                         usage_with_options(builtin_rebase_usage,
2002                                            builtin_rebase_options);
2003                 options.upstream_arg = "--root";
2004         }
2005
2006         /* Make sure the branch to rebase onto is valid. */
2007         if (keep_base) {
2008                 strbuf_reset(&buf);
2009                 strbuf_addstr(&buf, options.upstream_name);
2010                 strbuf_addstr(&buf, "...");
2011                 options.onto_name = xstrdup(buf.buf);
2012         } else if (!options.onto_name)
2013                 options.onto_name = options.upstream_name;
2014         if (strstr(options.onto_name, "...")) {
2015                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
2016                         if (keep_base)
2017                                 die(_("'%s': need exactly one merge base with branch"),
2018                                     options.upstream_name);
2019                         else
2020                                 die(_("'%s': need exactly one merge base"),
2021                                     options.onto_name);
2022                 }
2023                 options.onto = lookup_commit_or_die(&merge_base,
2024                                                     options.onto_name);
2025         } else {
2026                 options.onto = peel_committish(options.onto_name);
2027                 if (!options.onto)
2028                         die(_("Does not point to a valid commit '%s'"),
2029                                 options.onto_name);
2030         }
2031
2032         /*
2033          * If the branch to rebase is given, that is the branch we will rebase
2034          * branch_name -- branch/commit being rebased, or
2035          *                HEAD (already detached)
2036          * orig_head -- commit object name of tip of the branch before rebasing
2037          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
2038          */
2039         if (argc == 1) {
2040                 /* Is it "rebase other branchname" or "rebase other commit"? */
2041                 branch_name = argv[0];
2042                 options.switch_to = argv[0];
2043
2044                 /* Is it a local branch? */
2045                 strbuf_reset(&buf);
2046                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
2047                 if (!read_ref(buf.buf, &options.orig_head)) {
2048                         die_if_checked_out(buf.buf, 1);
2049                         options.head_name = xstrdup(buf.buf);
2050                 /* If not is it a valid ref (branch or commit)? */
2051                 } else if (!get_oid(branch_name, &options.orig_head))
2052                         options.head_name = NULL;
2053                 else
2054                         die(_("fatal: no such branch/commit '%s'"),
2055                             branch_name);
2056         } else if (argc == 0) {
2057                 /* Do not need to switch branches, we are already on it. */
2058                 options.head_name =
2059                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
2060                                          &flags));
2061                 if (!options.head_name)
2062                         die(_("No such ref: %s"), "HEAD");
2063                 if (flags & REF_ISSYMREF) {
2064                         if (!skip_prefix(options.head_name,
2065                                          "refs/heads/", &branch_name))
2066                                 branch_name = options.head_name;
2067
2068                 } else {
2069                         FREE_AND_NULL(options.head_name);
2070                         branch_name = "HEAD";
2071                 }
2072                 if (get_oid("HEAD", &options.orig_head))
2073                         die(_("Could not resolve HEAD to a revision"));
2074         } else
2075                 BUG("unexpected number of arguments left to parse");
2076
2077         if (fork_point > 0) {
2078                 struct commit *head =
2079                         lookup_commit_reference(the_repository,
2080                                                 &options.orig_head);
2081                 options.restrict_revision =
2082                         get_fork_point(options.upstream_name, head);
2083         }
2084
2085         if (repo_read_index(the_repository) < 0)
2086                 die(_("could not read index"));
2087
2088         if (options.autostash) {
2089                 struct lock_file lock_file = LOCK_INIT;
2090                 int fd;
2091
2092                 fd = hold_locked_index(&lock_file, 0);
2093                 refresh_cache(REFRESH_QUIET);
2094                 if (0 <= fd)
2095                         repo_update_index_if_able(the_repository, &lock_file);
2096                 rollback_lock_file(&lock_file);
2097
2098                 if (has_unstaged_changes(the_repository, 1) ||
2099                     has_uncommitted_changes(the_repository, 1)) {
2100                         const char *autostash =
2101                                 state_dir_path("autostash", &options);
2102                         struct child_process stash = CHILD_PROCESS_INIT;
2103                         struct object_id oid;
2104
2105                         argv_array_pushl(&stash.args,
2106                                          "stash", "create", "autostash", NULL);
2107                         stash.git_cmd = 1;
2108                         stash.no_stdin = 1;
2109                         strbuf_reset(&buf);
2110                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
2111                                 die(_("Cannot autostash"));
2112                         strbuf_trim_trailing_newline(&buf);
2113                         if (get_oid(buf.buf, &oid))
2114                                 die(_("Unexpected stash response: '%s'"),
2115                                     buf.buf);
2116                         strbuf_reset(&buf);
2117                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
2118
2119                         if (safe_create_leading_directories_const(autostash))
2120                                 die(_("Could not create directory for '%s'"),
2121                                     options.state_dir);
2122                         write_file(autostash, "%s", oid_to_hex(&oid));
2123                         printf(_("Created autostash: %s\n"), buf.buf);
2124                         if (reset_head(NULL, "reset --hard",
2125                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2126                                 die(_("could not reset --hard"));
2127
2128                         if (discard_index(the_repository->index) < 0 ||
2129                                 repo_read_index(the_repository) < 0)
2130                                 die(_("could not read index"));
2131                 }
2132         }
2133
2134         if (require_clean_work_tree(the_repository, "rebase",
2135                                     _("Please commit or stash them."), 1, 1)) {
2136                 ret = 1;
2137                 goto cleanup;
2138         }
2139
2140         /*
2141          * Now we are rebasing commits upstream..orig_head (or with --root,
2142          * everything leading up to orig_head) on top of onto.
2143          */
2144
2145         /*
2146          * Check if we are already based on onto with linear history,
2147          * in which case we could fast-forward without replacing the commits
2148          * with new commits recreated by replaying their changes.
2149          *
2150          * Note that can_fast_forward() initializes merge_base, so we have to
2151          * call it before checking allow_preemptive_ff.
2152          */
2153         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
2154                     &options.orig_head, &merge_base) &&
2155             allow_preemptive_ff) {
2156                 int flag;
2157
2158                 if (!(options.flags & REBASE_FORCE)) {
2159                         /* Lazily switch to the target branch if needed... */
2160                         if (options.switch_to) {
2161                                 strbuf_reset(&buf);
2162                                 strbuf_addf(&buf, "%s: checkout %s",
2163                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2164                                             options.switch_to);
2165                                 if (reset_head(&options.orig_head, "checkout",
2166                                                options.head_name,
2167                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2168                                                NULL, buf.buf) < 0) {
2169                                         ret = !!error(_("could not switch to "
2170                                                         "%s"),
2171                                                       options.switch_to);
2172                                         goto cleanup;
2173                                 }
2174                         }
2175
2176                         if (!(options.flags & REBASE_NO_QUIET))
2177                                 ; /* be quiet */
2178                         else if (!strcmp(branch_name, "HEAD") &&
2179                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2180                                 puts(_("HEAD is up to date."));
2181                         else
2182                                 printf(_("Current branch %s is up to date.\n"),
2183                                        branch_name);
2184                         ret = !!finish_rebase(&options);
2185                         goto cleanup;
2186                 } else if (!(options.flags & REBASE_NO_QUIET))
2187                         ; /* be quiet */
2188                 else if (!strcmp(branch_name, "HEAD") &&
2189                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2190                         puts(_("HEAD is up to date, rebase forced."));
2191                 else
2192                         printf(_("Current branch %s is up to date, rebase "
2193                                  "forced.\n"), branch_name);
2194         }
2195
2196         /* If a hook exists, give it a chance to interrupt*/
2197         if (!ok_to_skip_pre_rebase &&
2198             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2199                         argc ? argv[0] : NULL, NULL))
2200                 die(_("The pre-rebase hook refused to rebase."));
2201
2202         if (options.flags & REBASE_DIFFSTAT) {
2203                 struct diff_options opts;
2204
2205                 if (options.flags & REBASE_VERBOSE) {
2206                         if (is_null_oid(&merge_base))
2207                                 printf(_("Changes to %s:\n"),
2208                                        oid_to_hex(&options.onto->object.oid));
2209                         else
2210                                 printf(_("Changes from %s to %s:\n"),
2211                                        oid_to_hex(&merge_base),
2212                                        oid_to_hex(&options.onto->object.oid));
2213                 }
2214
2215                 /* We want color (if set), but no pager */
2216                 diff_setup(&opts);
2217                 opts.stat_width = -1; /* use full terminal width */
2218                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2219                 opts.output_format |=
2220                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2221                 opts.detect_rename = DIFF_DETECT_RENAME;
2222                 diff_setup_done(&opts);
2223                 diff_tree_oid(is_null_oid(&merge_base) ?
2224                               the_hash_algo->empty_tree : &merge_base,
2225                               &options.onto->object.oid, "", &opts);
2226                 diffcore_std(&opts);
2227                 diff_flush(&opts);
2228         }
2229
2230         if (is_merge(&options))
2231                 goto run_rebase;
2232
2233         /* Detach HEAD and reset the tree */
2234         if (options.flags & REBASE_NO_QUIET)
2235                 printf(_("First, rewinding head to replay your work on top of "
2236                          "it...\n"));
2237
2238         strbuf_addf(&msg, "%s: checkout %s",
2239                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2240         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2241                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2242                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2243                        NULL, msg.buf))
2244                 die(_("Could not detach HEAD"));
2245         strbuf_release(&msg);
2246
2247         /*
2248          * If the onto is a proper descendant of the tip of the branch, then
2249          * we just fast-forwarded.
2250          */
2251         strbuf_reset(&msg);
2252         if (oideq(&merge_base, &options.orig_head)) {
2253                 printf(_("Fast-forwarded %s to %s.\n"),
2254                         branch_name, options.onto_name);
2255                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2256                         options.head_name ? options.head_name : "detached HEAD",
2257                         oid_to_hex(&options.onto->object.oid));
2258                 reset_head(NULL, "Fast-forwarded", options.head_name,
2259                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2260                 strbuf_release(&msg);
2261                 ret = !!finish_rebase(&options);
2262                 goto cleanup;
2263         }
2264
2265         strbuf_addf(&revisions, "%s..%s",
2266                     options.root ? oid_to_hex(&options.onto->object.oid) :
2267                     (options.restrict_revision ?
2268                      oid_to_hex(&options.restrict_revision->object.oid) :
2269                      oid_to_hex(&options.upstream->object.oid)),
2270                     oid_to_hex(&options.orig_head));
2271
2272         options.revisions = revisions.buf;
2273
2274 run_rebase:
2275         ret = !!run_specific_rebase(&options, action);
2276
2277 cleanup:
2278         strbuf_release(&buf);
2279         strbuf_release(&revisions);
2280         free(options.head_name);
2281         free(options.gpg_sign_opt);
2282         free(options.cmd);
2283         free(squash_onto_name);
2284         return ret;
2285 }