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", NULL);
1016         if (opts->git_format_patch_opt.len)
1017                 argv_array_split(&format_patch.args,
1018                                  opts->git_format_patch_opt.buf);
1019         argv_array_push(&format_patch.args, revisions.buf);
1020         if (opts->restrict_revision)
1021                 argv_array_pushf(&format_patch.args, "^%s",
1022                                  oid_to_hex(&opts->restrict_revision->object.oid));
1023
1024         status = run_command(&format_patch);
1025         if (status) {
1026                 unlink(rebased_patches);
1027                 free(rebased_patches);
1028                 argv_array_clear(&am.args);
1029
1030                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1031                            "HEAD", NULL);
1032                 error(_("\ngit encountered an error while preparing the "
1033                         "patches to replay\n"
1034                         "these revisions:\n"
1035                         "\n    %s\n\n"
1036                         "As a result, git cannot rebase them."),
1037                       opts->revisions);
1038
1039                 strbuf_release(&revisions);
1040                 return status;
1041         }
1042         strbuf_release(&revisions);
1043
1044         am.in = open(rebased_patches, O_RDONLY);
1045         if (am.in < 0) {
1046                 status = error_errno(_("could not open '%s' for reading"),
1047                                      rebased_patches);
1048                 free(rebased_patches);
1049                 argv_array_clear(&am.args);
1050                 return status;
1051         }
1052
1053         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1054         argv_array_push(&am.args, "--rebasing");
1055         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1056         argv_array_push(&am.args, "--patch-format=mboxrd");
1057         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1058                 argv_array_push(&am.args, "--rerere-autoupdate");
1059         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1060                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1061         if (opts->gpg_sign_opt)
1062                 argv_array_push(&am.args, opts->gpg_sign_opt);
1063         status = run_command(&am);
1064         unlink(rebased_patches);
1065         free(rebased_patches);
1066
1067         if (!status) {
1068                 return move_to_original_branch(opts);
1069         }
1070
1071         if (is_directory(opts->state_dir))
1072                 rebase_write_basic_state(opts);
1073
1074         return status;
1075 }
1076
1077 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1078 {
1079         const char *argv[] = { NULL, NULL };
1080         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1081         int status;
1082         const char *backend, *backend_func;
1083
1084         if (opts->type == REBASE_INTERACTIVE) {
1085                 /* Run builtin interactive rebase */
1086                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1087                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1088                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1089                         opts->autosquash = 0;
1090                 }
1091                 if (opts->gpg_sign_opt) {
1092                         /* remove the leading "-S" */
1093                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1094                         free(opts->gpg_sign_opt);
1095                         opts->gpg_sign_opt = tmp;
1096                 }
1097
1098                 status = run_rebase_interactive(opts, action);
1099                 goto finished_rebase;
1100         }
1101
1102         if (opts->type == REBASE_AM) {
1103                 status = run_am(opts);
1104                 goto finished_rebase;
1105         }
1106
1107         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1108         add_var(&script_snippet, "state_dir", opts->state_dir);
1109
1110         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1111         add_var(&script_snippet, "upstream", opts->upstream ?
1112                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1113         add_var(&script_snippet, "head_name",
1114                 opts->head_name ? opts->head_name : "detached HEAD");
1115         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1116         add_var(&script_snippet, "onto", opts->onto ?
1117                 oid_to_hex(&opts->onto->object.oid) : NULL);
1118         add_var(&script_snippet, "onto_name", opts->onto_name);
1119         add_var(&script_snippet, "revisions", opts->revisions);
1120         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1121                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1122         add_var(&script_snippet, "GIT_QUIET",
1123                 opts->flags & REBASE_NO_QUIET ? "" : "t");
1124         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1125         add_var(&script_snippet, "git_am_opt", buf.buf);
1126         strbuf_release(&buf);
1127         add_var(&script_snippet, "verbose",
1128                 opts->flags & REBASE_VERBOSE ? "t" : "");
1129         add_var(&script_snippet, "diffstat",
1130                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1131         add_var(&script_snippet, "force_rebase",
1132                 opts->flags & REBASE_FORCE ? "t" : "");
1133         if (opts->switch_to)
1134                 add_var(&script_snippet, "switch_to", opts->switch_to);
1135         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1136         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1137         add_var(&script_snippet, "allow_rerere_autoupdate",
1138                 opts->allow_rerere_autoupdate ?
1139                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1140                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1141         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1142         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1143         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1144         add_var(&script_snippet, "cmd", opts->cmd);
1145         add_var(&script_snippet, "allow_empty_message",
1146                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1147         add_var(&script_snippet, "rebase_merges",
1148                 opts->rebase_merges ? "t" : "");
1149         add_var(&script_snippet, "rebase_cousins",
1150                 opts->rebase_cousins ? "t" : "");
1151         add_var(&script_snippet, "strategy", opts->strategy);
1152         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1153         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1154         add_var(&script_snippet, "squash_onto",
1155                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1156         add_var(&script_snippet, "git_format_patch_opt",
1157                 opts->git_format_patch_opt.buf);
1158
1159         if (is_interactive(opts) &&
1160             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1161                 strbuf_addstr(&script_snippet,
1162                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1163                 opts->autosquash = 0;
1164         }
1165
1166         switch (opts->type) {
1167         case REBASE_PRESERVE_MERGES:
1168                 backend = "git-rebase--preserve-merges";
1169                 backend_func = "git_rebase__preserve_merges";
1170                 break;
1171         default:
1172                 BUG("Unhandled rebase type %d", opts->type);
1173                 break;
1174         }
1175
1176         strbuf_addf(&script_snippet,
1177                     ". git-sh-setup && . %s && %s", backend, backend_func);
1178         argv[0] = script_snippet.buf;
1179
1180         status = run_command_v_opt(argv, RUN_USING_SHELL);
1181 finished_rebase:
1182         if (opts->dont_finish_rebase)
1183                 ; /* do nothing */
1184         else if (opts->type == REBASE_INTERACTIVE)
1185                 ; /* interactive rebase cleans up after itself */
1186         else if (status == 0) {
1187                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1188                         finish_rebase(opts);
1189         } else if (status == 2) {
1190                 struct strbuf dir = STRBUF_INIT;
1191
1192                 apply_autostash(opts);
1193                 strbuf_addstr(&dir, opts->state_dir);
1194                 remove_dir_recursively(&dir, 0);
1195                 strbuf_release(&dir);
1196                 die("Nothing to do");
1197         }
1198
1199         strbuf_release(&script_snippet);
1200
1201         return status ? -1 : 0;
1202 }
1203
1204 static int rebase_config(const char *var, const char *value, void *data)
1205 {
1206         struct rebase_options *opts = data;
1207
1208         if (!strcmp(var, "rebase.stat")) {
1209                 if (git_config_bool(var, value))
1210                         opts->flags |= REBASE_DIFFSTAT;
1211                 else
1212                         opts->flags &= ~REBASE_DIFFSTAT;
1213                 return 0;
1214         }
1215
1216         if (!strcmp(var, "rebase.autosquash")) {
1217                 opts->autosquash = git_config_bool(var, value);
1218                 return 0;
1219         }
1220
1221         if (!strcmp(var, "commit.gpgsign")) {
1222                 free(opts->gpg_sign_opt);
1223                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1224                         xstrdup("-S") : NULL;
1225                 return 0;
1226         }
1227
1228         if (!strcmp(var, "rebase.autostash")) {
1229                 opts->autostash = git_config_bool(var, value);
1230                 return 0;
1231         }
1232
1233         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1234                 opts->reschedule_failed_exec = git_config_bool(var, value);
1235                 return 0;
1236         }
1237
1238         if (!strcmp(var, "rebase.usebuiltin")) {
1239                 opts->use_legacy_rebase = !git_config_bool(var, value);
1240                 return 0;
1241         }
1242
1243         return git_default_config(var, value, data);
1244 }
1245
1246 /*
1247  * Determines whether the commits in from..to are linear, i.e. contain
1248  * no merge commits. This function *expects* `from` to be an ancestor of
1249  * `to`.
1250  */
1251 static int is_linear_history(struct commit *from, struct commit *to)
1252 {
1253         while (to && to != from) {
1254                 parse_commit(to);
1255                 if (!to->parents)
1256                         return 1;
1257                 if (to->parents->next)
1258                         return 0;
1259                 to = to->parents->item;
1260         }
1261         return 1;
1262 }
1263
1264 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1265                             struct commit *restrict_revision,
1266                             struct object_id *head_oid, struct object_id *merge_base)
1267 {
1268         struct commit *head = lookup_commit(the_repository, head_oid);
1269         struct commit_list *merge_bases = NULL;
1270         int res = 0;
1271
1272         if (!head)
1273                 goto done;
1274
1275         merge_bases = get_merge_bases(onto, head);
1276         if (!merge_bases || merge_bases->next) {
1277                 oidcpy(merge_base, &null_oid);
1278                 goto done;
1279         }
1280
1281         oidcpy(merge_base, &merge_bases->item->object.oid);
1282         if (!oideq(merge_base, &onto->object.oid))
1283                 goto done;
1284
1285         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1286                 goto done;
1287
1288         if (!upstream)
1289                 goto done;
1290
1291         free_commit_list(merge_bases);
1292         merge_bases = get_merge_bases(upstream, head);
1293         if (!merge_bases || merge_bases->next)
1294                 goto done;
1295
1296         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1297                 goto done;
1298
1299         res = 1;
1300
1301 done:
1302         free_commit_list(merge_bases);
1303         return res && is_linear_history(onto, head);
1304 }
1305
1306 /* -i followed by -m is still -i */
1307 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1308 {
1309         struct rebase_options *opts = opt->value;
1310
1311         BUG_ON_OPT_NEG(unset);
1312         BUG_ON_OPT_ARG(arg);
1313
1314         if (!is_interactive(opts))
1315                 opts->type = REBASE_MERGE;
1316
1317         return 0;
1318 }
1319
1320 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1321 static int parse_opt_interactive(const struct option *opt, const char *arg,
1322                                  int unset)
1323 {
1324         struct rebase_options *opts = opt->value;
1325
1326         BUG_ON_OPT_NEG(unset);
1327         BUG_ON_OPT_ARG(arg);
1328
1329         opts->type = REBASE_INTERACTIVE;
1330         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1331
1332         return 0;
1333 }
1334
1335 static void NORETURN error_on_missing_default_upstream(void)
1336 {
1337         struct branch *current_branch = branch_get(NULL);
1338
1339         printf(_("%s\n"
1340                  "Please specify which branch you want to rebase against.\n"
1341                  "See git-rebase(1) for details.\n"
1342                  "\n"
1343                  "    git rebase '<branch>'\n"
1344                  "\n"),
1345                 current_branch ? _("There is no tracking information for "
1346                         "the current branch.") :
1347                         _("You are not currently on a branch."));
1348
1349         if (current_branch) {
1350                 const char *remote = current_branch->remote_name;
1351
1352                 if (!remote)
1353                         remote = _("<remote>");
1354
1355                 printf(_("If you wish to set tracking information for this "
1356                          "branch you can do so with:\n"
1357                          "\n"
1358                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1359                          "\n"),
1360                        remote, current_branch->name);
1361         }
1362         exit(1);
1363 }
1364
1365 static void set_reflog_action(struct rebase_options *options)
1366 {
1367         const char *env;
1368         struct strbuf buf = STRBUF_INIT;
1369
1370         if (!is_interactive(options))
1371                 return;
1372
1373         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1374         if (env && strcmp("rebase", env))
1375                 return; /* only override it if it is "rebase" */
1376
1377         strbuf_addf(&buf, "rebase -i (%s)", options->action);
1378         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1379         strbuf_release(&buf);
1380 }
1381
1382 static int check_exec_cmd(const char *cmd)
1383 {
1384         if (strchr(cmd, '\n'))
1385                 return error(_("exec commands cannot contain newlines"));
1386
1387         /* Does the command consist purely of whitespace? */
1388         if (!cmd[strspn(cmd, " \t\r\f\v")])
1389                 return error(_("empty exec command"));
1390
1391         return 0;
1392 }
1393
1394
1395 int cmd_rebase(int argc, const char **argv, const char *prefix)
1396 {
1397         struct rebase_options options = REBASE_OPTIONS_INIT;
1398         const char *branch_name;
1399         int ret, flags, total_argc, in_progress = 0;
1400         int keep_base = 0;
1401         int ok_to_skip_pre_rebase = 0;
1402         struct strbuf msg = STRBUF_INIT;
1403         struct strbuf revisions = STRBUF_INIT;
1404         struct strbuf buf = STRBUF_INIT;
1405         struct object_id merge_base;
1406         enum action action = ACTION_NONE;
1407         const char *gpg_sign = NULL;
1408         struct string_list exec = STRING_LIST_INIT_NODUP;
1409         const char *rebase_merges = NULL;
1410         int fork_point = -1;
1411         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1412         struct object_id squash_onto;
1413         char *squash_onto_name = NULL;
1414         int reschedule_failed_exec = -1;
1415         struct option builtin_rebase_options[] = {
1416                 OPT_STRING(0, "onto", &options.onto_name,
1417                            N_("revision"),
1418                            N_("rebase onto given branch instead of upstream")),
1419                 OPT_BOOL(0, "keep-base", &keep_base,
1420                          N_("use the merge-base of upstream and branch as the current base")),
1421                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1422                          N_("allow pre-rebase hook to run")),
1423                 OPT_NEGBIT('q', "quiet", &options.flags,
1424                            N_("be quiet. implies --no-stat"),
1425                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1426                 OPT_BIT('v', "verbose", &options.flags,
1427                         N_("display a diffstat of what changed upstream"),
1428                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1429                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1430                         N_("do not show diffstat of what changed upstream"),
1431                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1432                 OPT_BOOL(0, "signoff", &options.signoff,
1433                          N_("add a Signed-off-by: line to each commit")),
1434                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1435                                   NULL, N_("passed to 'git am'"),
1436                                   PARSE_OPT_NOARG),
1437                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1438                                   &options.git_am_opts, NULL,
1439                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1440                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1441                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1442                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1443                                   N_("passed to 'git apply'"), 0),
1444                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1445                                   N_("action"), N_("passed to 'git apply'"), 0),
1446                 OPT_BIT('f', "force-rebase", &options.flags,
1447                         N_("cherry-pick all commits, even if unchanged"),
1448                         REBASE_FORCE),
1449                 OPT_BIT(0, "no-ff", &options.flags,
1450                         N_("cherry-pick all commits, even if unchanged"),
1451                         REBASE_FORCE),
1452                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1453                             ACTION_CONTINUE),
1454                 OPT_CMDMODE(0, "skip", &action,
1455                             N_("skip current patch and continue"), ACTION_SKIP),
1456                 OPT_CMDMODE(0, "abort", &action,
1457                             N_("abort and check out the original branch"),
1458                             ACTION_ABORT),
1459                 OPT_CMDMODE(0, "quit", &action,
1460                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1461                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1462                             "during an interactive rebase"), ACTION_EDIT_TODO),
1463                 OPT_CMDMODE(0, "show-current-patch", &action,
1464                             N_("show the patch file being applied or merged"),
1465                             ACTION_SHOW_CURRENT_PATCH),
1466                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1467                         N_("use merging strategies to rebase"),
1468                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1469                         parse_opt_merge },
1470                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1471                         N_("let the user edit the list of commits to rebase"),
1472                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1473                         parse_opt_interactive },
1474                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1475                               N_("(DEPRECATED) try to recreate merges instead of "
1476                                  "ignoring them"),
1477                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1478                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1479                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
1480                          N_("preserve empty commits during rebase")),
1481                 OPT_BOOL(0, "autosquash", &options.autosquash,
1482                          N_("move commits that begin with "
1483                             "squash!/fixup! under -i")),
1484                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1485                         N_("GPG-sign commits"),
1486                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1487                 OPT_BOOL(0, "autostash", &options.autostash,
1488                          N_("automatically stash/stash pop before and after")),
1489                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1490                                 N_("add exec lines after each commit of the "
1491                                    "editable list")),
1492                 OPT_BOOL(0, "allow-empty-message",
1493                          &options.allow_empty_message,
1494                          N_("allow rebasing commits with empty messages")),
1495                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1496                         N_("mode"),
1497                         N_("try to rebase merges instead of skipping them"),
1498                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1499                 OPT_BOOL(0, "fork-point", &fork_point,
1500                          N_("use 'merge-base --fork-point' to refine upstream")),
1501                 OPT_STRING('s', "strategy", &options.strategy,
1502                            N_("strategy"), N_("use the given merge strategy")),
1503                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1504                                 N_("option"),
1505                                 N_("pass the argument through to the merge "
1506                                    "strategy")),
1507                 OPT_BOOL(0, "root", &options.root,
1508                          N_("rebase all reachable commits up to the root(s)")),
1509                 OPT_BOOL(0, "reschedule-failed-exec",
1510                          &reschedule_failed_exec,
1511                          N_("automatically re-schedule any `exec` that fails")),
1512                 OPT_END(),
1513         };
1514         int i;
1515
1516         if (argc == 2 && !strcmp(argv[1], "-h"))
1517                 usage_with_options(builtin_rebase_usage,
1518                                    builtin_rebase_options);
1519
1520         options.allow_empty_message = 1;
1521         git_config(rebase_config, &options);
1522
1523         if (options.use_legacy_rebase ||
1524             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1525                 warning(_("the rebase.useBuiltin support has been removed!\n"
1526                           "See its entry in 'git help config' for details."));
1527
1528         strbuf_reset(&buf);
1529         strbuf_addf(&buf, "%s/applying", apply_dir());
1530         if(file_exists(buf.buf))
1531                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1532
1533         if (is_directory(apply_dir())) {
1534                 options.type = REBASE_AM;
1535                 options.state_dir = apply_dir();
1536         } else if (is_directory(merge_dir())) {
1537                 strbuf_reset(&buf);
1538                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1539                 if (is_directory(buf.buf)) {
1540                         options.type = REBASE_PRESERVE_MERGES;
1541                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1542                 } else {
1543                         strbuf_reset(&buf);
1544                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1545                         if(file_exists(buf.buf)) {
1546                                 options.type = REBASE_INTERACTIVE;
1547                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1548                         } else
1549                                 options.type = REBASE_MERGE;
1550                 }
1551                 options.state_dir = merge_dir();
1552         }
1553
1554         if (options.type != REBASE_UNSPECIFIED)
1555                 in_progress = 1;
1556
1557         total_argc = argc;
1558         argc = parse_options(argc, argv, prefix,
1559                              builtin_rebase_options,
1560                              builtin_rebase_usage, 0);
1561
1562         if (action != ACTION_NONE && total_argc != 2) {
1563                 usage_with_options(builtin_rebase_usage,
1564                                    builtin_rebase_options);
1565         }
1566
1567         if (argc > 2)
1568                 usage_with_options(builtin_rebase_usage,
1569                                    builtin_rebase_options);
1570
1571         if (options.type == REBASE_PRESERVE_MERGES)
1572                 warning(_("git rebase --preserve-merges is deprecated. "
1573                           "Use --rebase-merges instead."));
1574
1575         if (keep_base) {
1576                 if (options.onto_name)
1577                         die(_("cannot combine '--keep-base' with '--onto'"));
1578                 if (options.root)
1579                         die(_("cannot combine '--keep-base' with '--root'"));
1580         }
1581
1582         if (action != ACTION_NONE && !in_progress)
1583                 die(_("No rebase in progress?"));
1584         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1585
1586         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1587                 die(_("The --edit-todo action can only be used during "
1588                       "interactive rebase."));
1589
1590         if (trace2_is_enabled()) {
1591                 if (is_interactive(&options))
1592                         trace2_cmd_mode("interactive");
1593                 else if (exec.nr)
1594                         trace2_cmd_mode("interactive-exec");
1595                 else
1596                         trace2_cmd_mode(action_names[action]);
1597         }
1598
1599         switch (action) {
1600         case ACTION_CONTINUE: {
1601                 struct object_id head;
1602                 struct lock_file lock_file = LOCK_INIT;
1603                 int fd;
1604
1605                 options.action = "continue";
1606                 set_reflog_action(&options);
1607
1608                 /* Sanity check */
1609                 if (get_oid("HEAD", &head))
1610                         die(_("Cannot read HEAD"));
1611
1612                 fd = hold_locked_index(&lock_file, 0);
1613                 if (repo_read_index(the_repository) < 0)
1614                         die(_("could not read index"));
1615                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1616                               NULL);
1617                 if (0 <= fd)
1618                         repo_update_index_if_able(the_repository, &lock_file);
1619                 rollback_lock_file(&lock_file);
1620
1621                 if (has_unstaged_changes(the_repository, 1)) {
1622                         puts(_("You must edit all merge conflicts and then\n"
1623                                "mark them as resolved using git add"));
1624                         exit(1);
1625                 }
1626                 if (read_basic_state(&options))
1627                         exit(1);
1628                 goto run_rebase;
1629         }
1630         case ACTION_SKIP: {
1631                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1632
1633                 options.action = "skip";
1634                 set_reflog_action(&options);
1635
1636                 rerere_clear(the_repository, &merge_rr);
1637                 string_list_clear(&merge_rr, 1);
1638
1639                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1640                                NULL, NULL) < 0)
1641                         die(_("could not discard worktree changes"));
1642                 remove_branch_state(the_repository, 0);
1643                 if (read_basic_state(&options))
1644                         exit(1);
1645                 goto run_rebase;
1646         }
1647         case ACTION_ABORT: {
1648                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1649                 options.action = "abort";
1650                 set_reflog_action(&options);
1651
1652                 rerere_clear(the_repository, &merge_rr);
1653                 string_list_clear(&merge_rr, 1);
1654
1655                 if (read_basic_state(&options))
1656                         exit(1);
1657                 if (reset_head(&options.orig_head, "reset",
1658                                options.head_name, RESET_HEAD_HARD,
1659                                NULL, NULL) < 0)
1660                         die(_("could not move back to %s"),
1661                             oid_to_hex(&options.orig_head));
1662                 remove_branch_state(the_repository, 0);
1663                 ret = !!finish_rebase(&options);
1664                 goto cleanup;
1665         }
1666         case ACTION_QUIT: {
1667                 if (options.type == REBASE_INTERACTIVE) {
1668                         struct replay_opts replay = REPLAY_OPTS_INIT;
1669
1670                         replay.action = REPLAY_INTERACTIVE_REBASE;
1671                         ret = !!sequencer_remove_state(&replay);
1672                 } else {
1673                         strbuf_reset(&buf);
1674                         strbuf_addstr(&buf, options.state_dir);
1675                         ret = !!remove_dir_recursively(&buf, 0);
1676                         if (ret)
1677                                 error(_("could not remove '%s'"),
1678                                        options.state_dir);
1679                 }
1680                 goto cleanup;
1681         }
1682         case ACTION_EDIT_TODO:
1683                 options.action = "edit-todo";
1684                 options.dont_finish_rebase = 1;
1685                 goto run_rebase;
1686         case ACTION_SHOW_CURRENT_PATCH:
1687                 options.action = "show-current-patch";
1688                 options.dont_finish_rebase = 1;
1689                 goto run_rebase;
1690         case ACTION_NONE:
1691                 break;
1692         default:
1693                 BUG("action: %d", action);
1694         }
1695
1696         /* Make sure no rebase is in progress */
1697         if (in_progress) {
1698                 const char *last_slash = strrchr(options.state_dir, '/');
1699                 const char *state_dir_base =
1700                         last_slash ? last_slash + 1 : options.state_dir;
1701                 const char *cmd_live_rebase =
1702                         "git rebase (--continue | --abort | --skip)";
1703                 strbuf_reset(&buf);
1704                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1705                 die(_("It seems that there is already a %s directory, and\n"
1706                       "I wonder if you are in the middle of another rebase.  "
1707                       "If that is the\n"
1708                       "case, please try\n\t%s\n"
1709                       "If that is not the case, please\n\t%s\n"
1710                       "and run me again.  I am stopping in case you still "
1711                       "have something\n"
1712                       "valuable there.\n"),
1713                     state_dir_base, cmd_live_rebase, buf.buf);
1714         }
1715
1716         for (i = 0; i < options.git_am_opts.argc; i++) {
1717                 const char *option = options.git_am_opts.argv[i], *p;
1718                 if (!strcmp(option, "--committer-date-is-author-date") ||
1719                     !strcmp(option, "--ignore-date") ||
1720                     !strcmp(option, "--whitespace=fix") ||
1721                     !strcmp(option, "--whitespace=strip"))
1722                         options.flags |= REBASE_FORCE;
1723                 else if (skip_prefix(option, "-C", &p)) {
1724                         while (*p)
1725                                 if (!isdigit(*(p++)))
1726                                         die(_("switch `C' expects a "
1727                                               "numerical value"));
1728                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1729                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1730                             strcmp(p, "error") && strcmp(p, "error-all"))
1731                                 die("Invalid whitespace option: '%s'", p);
1732                 }
1733         }
1734
1735         for (i = 0; i < exec.nr; i++)
1736                 if (check_exec_cmd(exec.items[i].string))
1737                         exit(1);
1738
1739         if (!(options.flags & REBASE_NO_QUIET))
1740                 argv_array_push(&options.git_am_opts, "-q");
1741
1742         if (options.keep_empty)
1743                 imply_interactive(&options, "--keep-empty");
1744
1745         if (gpg_sign) {
1746                 free(options.gpg_sign_opt);
1747                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1748         }
1749
1750         if (exec.nr) {
1751                 int i;
1752
1753                 imply_interactive(&options, "--exec");
1754
1755                 strbuf_reset(&buf);
1756                 for (i = 0; i < exec.nr; i++)
1757                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1758                 options.cmd = xstrdup(buf.buf);
1759         }
1760
1761         if (rebase_merges) {
1762                 if (!*rebase_merges)
1763                         ; /* default mode; do nothing */
1764                 else if (!strcmp("rebase-cousins", rebase_merges))
1765                         options.rebase_cousins = 1;
1766                 else if (strcmp("no-rebase-cousins", rebase_merges))
1767                         die(_("Unknown mode: %s"), rebase_merges);
1768                 options.rebase_merges = 1;
1769                 imply_interactive(&options, "--rebase-merges");
1770         }
1771
1772         if (strategy_options.nr) {
1773                 int i;
1774
1775                 if (!options.strategy)
1776                         options.strategy = "recursive";
1777
1778                 strbuf_reset(&buf);
1779                 for (i = 0; i < strategy_options.nr; i++)
1780                         strbuf_addf(&buf, " --%s",
1781                                     strategy_options.items[i].string);
1782                 options.strategy_opts = xstrdup(buf.buf);
1783         }
1784
1785         if (options.strategy) {
1786                 options.strategy = xstrdup(options.strategy);
1787                 switch (options.type) {
1788                 case REBASE_AM:
1789                         die(_("--strategy requires --merge or --interactive"));
1790                 case REBASE_MERGE:
1791                 case REBASE_INTERACTIVE:
1792                 case REBASE_PRESERVE_MERGES:
1793                         /* compatible */
1794                         break;
1795                 case REBASE_UNSPECIFIED:
1796                         options.type = REBASE_MERGE;
1797                         break;
1798                 default:
1799                         BUG("unhandled rebase type (%d)", options.type);
1800                 }
1801         }
1802
1803         if (options.type == REBASE_MERGE)
1804                 imply_interactive(&options, "--merge");
1805
1806         if (options.root && !options.onto_name)
1807                 imply_interactive(&options, "--root without --onto");
1808
1809         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1810                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1811
1812         switch (options.type) {
1813         case REBASE_MERGE:
1814         case REBASE_INTERACTIVE:
1815         case REBASE_PRESERVE_MERGES:
1816                 options.state_dir = merge_dir();
1817                 break;
1818         case REBASE_AM:
1819                 options.state_dir = apply_dir();
1820                 break;
1821         default:
1822                 /* the default rebase backend is `--am` */
1823                 options.type = REBASE_AM;
1824                 options.state_dir = apply_dir();
1825                 break;
1826         }
1827
1828         if (reschedule_failed_exec > 0 && !is_interactive(&options))
1829                 die(_("--reschedule-failed-exec requires "
1830                       "--exec or --interactive"));
1831         if (reschedule_failed_exec >= 0)
1832                 options.reschedule_failed_exec = reschedule_failed_exec;
1833
1834         if (options.git_am_opts.argc) {
1835                 /* all am options except -q are compatible only with --am */
1836                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1837                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1838                                 break;
1839
1840                 if (is_interactive(&options) && i >= 0)
1841                         die(_("cannot combine am options with either "
1842                               "interactive or merge options"));
1843         }
1844
1845         if (options.signoff) {
1846                 if (options.type == REBASE_PRESERVE_MERGES)
1847                         die("cannot combine '--signoff' with "
1848                             "'--preserve-merges'");
1849                 argv_array_push(&options.git_am_opts, "--signoff");
1850                 options.flags |= REBASE_FORCE;
1851         }
1852
1853         if (options.type == REBASE_PRESERVE_MERGES) {
1854                 /*
1855                  * Note: incompatibility with --signoff handled in signoff block above
1856                  * Note: incompatibility with --interactive is just a strong warning;
1857                  *       git-rebase.txt caveats with "unless you know what you are doing"
1858                  */
1859                 if (options.rebase_merges)
1860                         die(_("cannot combine '--preserve-merges' with "
1861                               "'--rebase-merges'"));
1862
1863                 if (options.reschedule_failed_exec)
1864                         die(_("error: cannot combine '--preserve-merges' with "
1865                               "'--reschedule-failed-exec'"));
1866         }
1867
1868         if (!options.root) {
1869                 if (argc < 1) {
1870                         struct branch *branch;
1871
1872                         branch = branch_get(NULL);
1873                         options.upstream_name = branch_get_upstream(branch,
1874                                                                     NULL);
1875                         if (!options.upstream_name)
1876                                 error_on_missing_default_upstream();
1877                         if (fork_point < 0)
1878                                 fork_point = 1;
1879                 } else {
1880                         options.upstream_name = argv[0];
1881                         argc--;
1882                         argv++;
1883                         if (!strcmp(options.upstream_name, "-"))
1884                                 options.upstream_name = "@{-1}";
1885                 }
1886                 options.upstream = peel_committish(options.upstream_name);
1887                 if (!options.upstream)
1888                         die(_("invalid upstream '%s'"), options.upstream_name);
1889                 options.upstream_arg = options.upstream_name;
1890         } else {
1891                 if (!options.onto_name) {
1892                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1893                                         &squash_onto, NULL, NULL) < 0)
1894                                 die(_("Could not create new root commit"));
1895                         options.squash_onto = &squash_onto;
1896                         options.onto_name = squash_onto_name =
1897                                 xstrdup(oid_to_hex(&squash_onto));
1898                 } else
1899                         options.root_with_onto = 1;
1900
1901                 options.upstream_name = NULL;
1902                 options.upstream = NULL;
1903                 if (argc > 1)
1904                         usage_with_options(builtin_rebase_usage,
1905                                            builtin_rebase_options);
1906                 options.upstream_arg = "--root";
1907         }
1908
1909         /* Make sure the branch to rebase onto is valid. */
1910         if (keep_base) {
1911                 strbuf_reset(&buf);
1912                 strbuf_addstr(&buf, options.upstream_name);
1913                 strbuf_addstr(&buf, "...");
1914                 options.onto_name = xstrdup(buf.buf);
1915         } else if (!options.onto_name)
1916                 options.onto_name = options.upstream_name;
1917         if (strstr(options.onto_name, "...")) {
1918                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
1919                         if (keep_base)
1920                                 die(_("'%s': need exactly one merge base with branch"),
1921                                     options.upstream_name);
1922                         else
1923                                 die(_("'%s': need exactly one merge base"),
1924                                     options.onto_name);
1925                 }
1926                 options.onto = lookup_commit_or_die(&merge_base,
1927                                                     options.onto_name);
1928         } else {
1929                 options.onto = peel_committish(options.onto_name);
1930                 if (!options.onto)
1931                         die(_("Does not point to a valid commit '%s'"),
1932                                 options.onto_name);
1933         }
1934
1935         /*
1936          * If the branch to rebase is given, that is the branch we will rebase
1937          * branch_name -- branch/commit being rebased, or
1938          *                HEAD (already detached)
1939          * orig_head -- commit object name of tip of the branch before rebasing
1940          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1941          */
1942         if (argc == 1) {
1943                 /* Is it "rebase other branchname" or "rebase other commit"? */
1944                 branch_name = argv[0];
1945                 options.switch_to = argv[0];
1946
1947                 /* Is it a local branch? */
1948                 strbuf_reset(&buf);
1949                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1950                 if (!read_ref(buf.buf, &options.orig_head))
1951                         options.head_name = xstrdup(buf.buf);
1952                 /* If not is it a valid ref (branch or commit)? */
1953                 else if (!get_oid(branch_name, &options.orig_head))
1954                         options.head_name = NULL;
1955                 else
1956                         die(_("fatal: no such branch/commit '%s'"),
1957                             branch_name);
1958         } else if (argc == 0) {
1959                 /* Do not need to switch branches, we are already on it. */
1960                 options.head_name =
1961                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1962                                          &flags));
1963                 if (!options.head_name)
1964                         die(_("No such ref: %s"), "HEAD");
1965                 if (flags & REF_ISSYMREF) {
1966                         if (!skip_prefix(options.head_name,
1967                                          "refs/heads/", &branch_name))
1968                                 branch_name = options.head_name;
1969
1970                 } else {
1971                         FREE_AND_NULL(options.head_name);
1972                         branch_name = "HEAD";
1973                 }
1974                 if (get_oid("HEAD", &options.orig_head))
1975                         die(_("Could not resolve HEAD to a revision"));
1976         } else
1977                 BUG("unexpected number of arguments left to parse");
1978
1979         if (fork_point > 0) {
1980                 struct commit *head =
1981                         lookup_commit_reference(the_repository,
1982                                                 &options.orig_head);
1983                 options.restrict_revision =
1984                         get_fork_point(options.upstream_name, head);
1985         }
1986
1987         if (repo_read_index(the_repository) < 0)
1988                 die(_("could not read index"));
1989
1990         if (options.autostash) {
1991                 struct lock_file lock_file = LOCK_INIT;
1992                 int fd;
1993
1994                 fd = hold_locked_index(&lock_file, 0);
1995                 refresh_cache(REFRESH_QUIET);
1996                 if (0 <= fd)
1997                         repo_update_index_if_able(the_repository, &lock_file);
1998                 rollback_lock_file(&lock_file);
1999
2000                 if (has_unstaged_changes(the_repository, 1) ||
2001                     has_uncommitted_changes(the_repository, 1)) {
2002                         const char *autostash =
2003                                 state_dir_path("autostash", &options);
2004                         struct child_process stash = CHILD_PROCESS_INIT;
2005                         struct object_id oid;
2006
2007                         argv_array_pushl(&stash.args,
2008                                          "stash", "create", "autostash", NULL);
2009                         stash.git_cmd = 1;
2010                         stash.no_stdin = 1;
2011                         strbuf_reset(&buf);
2012                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
2013                                 die(_("Cannot autostash"));
2014                         strbuf_trim_trailing_newline(&buf);
2015                         if (get_oid(buf.buf, &oid))
2016                                 die(_("Unexpected stash response: '%s'"),
2017                                     buf.buf);
2018                         strbuf_reset(&buf);
2019                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
2020
2021                         if (safe_create_leading_directories_const(autostash))
2022                                 die(_("Could not create directory for '%s'"),
2023                                     options.state_dir);
2024                         write_file(autostash, "%s", oid_to_hex(&oid));
2025                         printf(_("Created autostash: %s\n"), buf.buf);
2026                         if (reset_head(NULL, "reset --hard",
2027                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2028                                 die(_("could not reset --hard"));
2029
2030                         if (discard_index(the_repository->index) < 0 ||
2031                                 repo_read_index(the_repository) < 0)
2032                                 die(_("could not read index"));
2033                 }
2034         }
2035
2036         if (require_clean_work_tree(the_repository, "rebase",
2037                                     _("Please commit or stash them."), 1, 1)) {
2038                 ret = 1;
2039                 goto cleanup;
2040         }
2041
2042         /*
2043          * Now we are rebasing commits upstream..orig_head (or with --root,
2044          * everything leading up to orig_head) on top of onto.
2045          */
2046
2047         /*
2048          * Check if we are already based on onto with linear history,
2049          * in which case we could fast-forward without replacing the commits
2050          * with new commits recreated by replaying their changes. This
2051          * optimization must not be done if this is an interactive rebase.
2052          */
2053         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
2054                     &options.orig_head, &merge_base) &&
2055             !is_interactive(&options)) {
2056                 int flag;
2057
2058                 if (!(options.flags & REBASE_FORCE)) {
2059                         /* Lazily switch to the target branch if needed... */
2060                         if (options.switch_to) {
2061                                 struct object_id oid;
2062
2063                                 if (get_oid(options.switch_to, &oid) < 0) {
2064                                         ret = !!error(_("could not parse '%s'"),
2065                                                       options.switch_to);
2066                                         goto cleanup;
2067                                 }
2068
2069                                 strbuf_reset(&buf);
2070                                 strbuf_addf(&buf, "%s: checkout %s",
2071                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2072                                             options.switch_to);
2073                                 if (reset_head(&oid, "checkout",
2074                                                options.head_name,
2075                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2076                                                NULL, buf.buf) < 0) {
2077                                         ret = !!error(_("could not switch to "
2078                                                         "%s"),
2079                                                       options.switch_to);
2080                                         goto cleanup;
2081                                 }
2082                         }
2083
2084                         if (!(options.flags & REBASE_NO_QUIET))
2085                                 ; /* be quiet */
2086                         else if (!strcmp(branch_name, "HEAD") &&
2087                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2088                                 puts(_("HEAD is up to date."));
2089                         else
2090                                 printf(_("Current branch %s is up to date.\n"),
2091                                        branch_name);
2092                         ret = !!finish_rebase(&options);
2093                         goto cleanup;
2094                 } else if (!(options.flags & REBASE_NO_QUIET))
2095                         ; /* be quiet */
2096                 else if (!strcmp(branch_name, "HEAD") &&
2097                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2098                         puts(_("HEAD is up to date, rebase forced."));
2099                 else
2100                         printf(_("Current branch %s is up to date, rebase "
2101                                  "forced.\n"), branch_name);
2102         }
2103
2104         /* If a hook exists, give it a chance to interrupt*/
2105         if (!ok_to_skip_pre_rebase &&
2106             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2107                         argc ? argv[0] : NULL, NULL))
2108                 die(_("The pre-rebase hook refused to rebase."));
2109
2110         if (options.flags & REBASE_DIFFSTAT) {
2111                 struct diff_options opts;
2112
2113                 if (options.flags & REBASE_VERBOSE) {
2114                         if (is_null_oid(&merge_base))
2115                                 printf(_("Changes to %s:\n"),
2116                                        oid_to_hex(&options.onto->object.oid));
2117                         else
2118                                 printf(_("Changes from %s to %s:\n"),
2119                                        oid_to_hex(&merge_base),
2120                                        oid_to_hex(&options.onto->object.oid));
2121                 }
2122
2123                 /* We want color (if set), but no pager */
2124                 diff_setup(&opts);
2125                 opts.stat_width = -1; /* use full terminal width */
2126                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2127                 opts.output_format |=
2128                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2129                 opts.detect_rename = DIFF_DETECT_RENAME;
2130                 diff_setup_done(&opts);
2131                 diff_tree_oid(is_null_oid(&merge_base) ?
2132                               the_hash_algo->empty_tree : &merge_base,
2133                               &options.onto->object.oid, "", &opts);
2134                 diffcore_std(&opts);
2135                 diff_flush(&opts);
2136         }
2137
2138         if (is_interactive(&options))
2139                 goto run_rebase;
2140
2141         /* Detach HEAD and reset the tree */
2142         if (options.flags & REBASE_NO_QUIET)
2143                 printf(_("First, rewinding head to replay your work on top of "
2144                          "it...\n"));
2145
2146         strbuf_addf(&msg, "%s: checkout %s",
2147                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2148         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2149                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2150                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2151                        NULL, msg.buf))
2152                 die(_("Could not detach HEAD"));
2153         strbuf_release(&msg);
2154
2155         /*
2156          * If the onto is a proper descendant of the tip of the branch, then
2157          * we just fast-forwarded.
2158          */
2159         strbuf_reset(&msg);
2160         if (oideq(&merge_base, &options.orig_head)) {
2161                 printf(_("Fast-forwarded %s to %s.\n"),
2162                         branch_name, options.onto_name);
2163                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2164                         options.head_name ? options.head_name : "detached HEAD",
2165                         oid_to_hex(&options.onto->object.oid));
2166                 reset_head(NULL, "Fast-forwarded", options.head_name,
2167                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2168                 strbuf_release(&msg);
2169                 ret = !!finish_rebase(&options);
2170                 goto cleanup;
2171         }
2172
2173         strbuf_addf(&revisions, "%s..%s",
2174                     options.root ? oid_to_hex(&options.onto->object.oid) :
2175                     (options.restrict_revision ?
2176                      oid_to_hex(&options.restrict_revision->object.oid) :
2177                      oid_to_hex(&options.upstream->object.oid)),
2178                     oid_to_hex(&options.orig_head));
2179
2180         options.revisions = revisions.buf;
2181
2182 run_rebase:
2183         ret = !!run_specific_rebase(&options, action);
2184
2185 cleanup:
2186         strbuf_release(&buf);
2187         strbuf_release(&revisions);
2188         free(options.head_name);
2189         free(options.gpg_sign_opt);
2190         free(options.cmd);
2191         free(squash_onto_name);
2192         return ret;
2193 }