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

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