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

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