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