builtin/rebase.c

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   8 #include "builtin.h"
   9 #include "run-command.h"
  10 #include "exec-cmd.h"
  11 #include "argv-array.h"
  12 #include "dir.h"
  13 #include "packfile.h"
  14 #include "refs.h"
  15 #include "quote.h"
  16 #include "config.h"
  17 #include "cache-tree.h"
  18 #include "unpack-trees.h"
  19 #include "lockfile.h"
  20 #include "parse-options.h"
  21 #include "commit.h"
  22 #include "diff.h"
  23 #include "wt-status.h"
  24 #include "revision.h"
  25 #include "commit-reach.h"
  26 #include "rerere.h"
  27 #include "branch.h"
  28 #include "sequencer.h"
  29 #include "rebase-interactive.h"
  30
  31 static char const * const builtin_rebase_usage[] = {
  32         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  33                 "[<upstream>] [<branch>]"),
  34         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  35                 "--root [<branch>]"),
  36         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  37         NULL
  38 };
  39
  40 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
  41 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
  42 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  43 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  44
  45 enum rebase_type {
  46         REBASE_UNSPECIFIED = -1,
  47         REBASE_AM,
  48         REBASE_MERGE,
  49         REBASE_INTERACTIVE,
  50         REBASE_PRESERVE_MERGES
  51 };
  52
  53 struct rebase_options {
  54         enum rebase_type type;
  55         const char *state_dir;
  56         struct commit *upstream;
  57         const char *upstream_name;
  58         const char *upstream_arg;
  59         char *head_name;
  60         struct object_id orig_head;
  61         struct commit *onto;
  62         const char *onto_name;
  63         const char *revisions;
  64         const char *switch_to;
  65         int root;
  66         struct object_id *squash_onto;
  67         struct commit *restrict_revision;
  68         int dont_finish_rebase;
  69         enum {
  70                 REBASE_NO_QUIET = 1<<0,
  71                 REBASE_VERBOSE = 1<<1,
  72                 REBASE_DIFFSTAT = 1<<2,
  73                 REBASE_FORCE = 1<<3,
  74                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  75         } flags;
  76         struct argv_array git_am_opts;
  77         const char *action;
  78         int signoff;
  79         int allow_rerere_autoupdate;
  80         int keep_empty;
  81         int autosquash;
  82         char *gpg_sign_opt;
  83         int autostash;
  84         char *cmd;
  85         int allow_empty_message;
  86         int rebase_merges, rebase_cousins;
  87         char *strategy, *strategy_opts;
  88         struct strbuf git_format_patch_opt;
  89         int reschedule_failed_exec;
  90         int use_legacy_rebase;
  91 };
  92
  93 #define REBASE_OPTIONS_INIT {                           \
  94                 .type = REBASE_UNSPECIFIED,             \
  95                 .flags = REBASE_NO_QUIET,               \
  96                 .git_am_opts = ARGV_ARRAY_INIT,         \
  97                 .git_format_patch_opt = STRBUF_INIT     \
  98         }
  99
 100 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 101 {
 102         struct replay_opts replay = REPLAY_OPTS_INIT;
 103
 104         replay.action = REPLAY_INTERACTIVE_REBASE;
 105         sequencer_init_config(&replay);
 106
 107         replay.signoff = opts->signoff;
 108         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 109         if (opts->allow_rerere_autoupdate)
 110                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 111         replay.allow_empty = 1;
 112         replay.allow_empty_message = opts->allow_empty_message;
 113         replay.verbose = opts->flags & REBASE_VERBOSE;
 114         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 115         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 116         replay.strategy = opts->strategy;
 117         if (opts->strategy_opts)
 118                 parse_strategy_opts(&replay, opts->strategy_opts);
 119
 120         return replay;
 121 }
 122
 123 enum action {
 124         ACTION_NONE = 0,
 125         ACTION_CONTINUE,
 126         ACTION_SKIP,
 127         ACTION_ABORT,
 128         ACTION_QUIT,
 129         ACTION_EDIT_TODO,
 130         ACTION_SHOW_CURRENT_PATCH,
 131         ACTION_SHORTEN_OIDS,
 132         ACTION_EXPAND_OIDS,
 133         ACTION_CHECK_TODO_LIST,
 134         ACTION_REARRANGE_SQUASH,
 135         ACTION_ADD_EXEC
 136 };
 137
 138 static const char *action_names[] = { "undefined",
 139                                       "continue",
 140                                       "skip",
 141                                       "abort",
 142                                       "quit",
 143                                       "edit_todo",
 144                                       "show_current_patch" };
 145
 146 static int add_exec_commands(struct string_list *commands)
 147 {
 148         const char *todo_file = rebase_path_todo();
 149         struct todo_list todo_list = TODO_LIST_INIT;
 150         int res;
 151
 152         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 153                 return error_errno(_("could not read '%s'."), todo_file);
 154
 155         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 156                                         &todo_list)) {
 157                 todo_list_release(&todo_list);
 158                 return error(_("unusable todo list: '%s'"), todo_file);
 159         }
 160
 161         todo_list_add_exec_commands(&todo_list, commands);
 162         res = todo_list_write_to_file(the_repository, &todo_list,
 163                                       todo_file, NULL, NULL, -1, 0);
 164         todo_list_release(&todo_list);
 165
 166         if (res)
 167                 return error_errno(_("could not write '%s'."), todo_file);
 168         return 0;
 169 }
 170
 171 static int rearrange_squash_in_todo_file(void)
 172 {
 173         const char *todo_file = rebase_path_todo();
 174         struct todo_list todo_list = TODO_LIST_INIT;
 175         int res = 0;
 176
 177         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 178                 return error_errno(_("could not read '%s'."), todo_file);
 179         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 180                                         &todo_list)) {
 181                 todo_list_release(&todo_list);
 182                 return error(_("unusable todo list: '%s'"), todo_file);
 183         }
 184
 185         res = todo_list_rearrange_squash(&todo_list);
 186         if (!res)
 187                 res = todo_list_write_to_file(the_repository, &todo_list,
 188                                               todo_file, NULL, NULL, -1, 0);
 189
 190         todo_list_release(&todo_list);
 191
 192         if (res)
 193                 return error_errno(_("could not write '%s'."), todo_file);
 194         return 0;
 195 }
 196
 197 static int transform_todo_file(unsigned flags)
 198 {
 199         const char *todo_file = rebase_path_todo();
 200         struct todo_list todo_list = TODO_LIST_INIT;
 201         int res;
 202
 203         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 204                 return error_errno(_("could not read '%s'."), todo_file);
 205
 206         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 207                                         &todo_list)) {
 208                 todo_list_release(&todo_list);
 209                 return error(_("unusable todo list: '%s'"), todo_file);
 210         }
 211
 212         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 213                                       NULL, NULL, -1, flags);
 214         todo_list_release(&todo_list);
 215
 216         if (res)
 217                 return error_errno(_("could not write '%s'."), todo_file);
 218         return 0;
 219 }
 220
 221 static int edit_todo_file(unsigned flags)
 222 {
 223         const char *todo_file = rebase_path_todo();
 224         struct todo_list todo_list = TODO_LIST_INIT,
 225                 new_todo = TODO_LIST_INIT;
 226         int res = 0;
 227
 228         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 229                 return error_errno(_("could not read '%s'."), todo_file);
 230
 231         strbuf_stripspace(&todo_list.buf, 1);
 232         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 233         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 234                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 235                 res = error_errno(_("could not write '%s'"), todo_file);
 236
 237         todo_list_release(&todo_list);
 238         todo_list_release(&new_todo);
 239
 240         return res;
 241 }
 242
 243 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 244                                const char **head_hash,
 245                                char **revisions, char **shortrevisions)
 246 {
 247         struct commit *base_rev = upstream ? upstream : onto;
 248         const char *shorthead;
 249         struct object_id orig_head;
 250
 251         if (get_oid("HEAD", &orig_head))
 252                 return error(_("no HEAD?"));
 253
 254         *head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
 255         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 256                                                    *head_hash);
 257
 258         shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
 259
 260         if (upstream) {
 261                 const char *shortrev;
 262
 263                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 264                                               DEFAULT_ABBREV);
 265
 266                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 267         } else
 268                 *shortrevisions = xstrdup(shorthead);
 269
 270         return 0;
 271 }
 272
 273 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 274                             struct commit *onto, const char *orig_head)
 275 {
 276         FILE *interactive;
 277
 278         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 279                 return error_errno(_("could not create temporary %s"), merge_dir());
 280
 281         delete_reflog("REBASE_HEAD");
 282
 283         interactive = fopen(path_interactive(), "w");
 284         if (!interactive)
 285                 return error_errno(_("could not mark as interactive"));
 286         fclose(interactive);
 287
 288         return write_basic_state(opts, head_name, onto, orig_head);
 289 }
 290
 291 static void split_exec_commands(const char *cmd, struct string_list *commands)
 292 {
 293         if (cmd && *cmd) {
 294                 string_list_split(commands, cmd, '\n', -1);
 295
 296                 /* rebase.c adds a new line to cmd after every command,
 297                  * so here the last command is always empty */
 298                 string_list_remove_empty_items(commands, 0);
 299         }
 300 }
 301
 302 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 303 {
 304         int ret;
 305         const char *head_hash = NULL;
 306         char *revisions = NULL, *shortrevisions = NULL;
 307         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 308         struct todo_list todo_list = TODO_LIST_INIT;
 309         struct replay_opts replay = get_replay_opts(opts);
 310         struct string_list commands = STRING_LIST_INIT_DUP;
 311
 312         if (prepare_branch_to_be_rebased(the_repository, &replay,
 313                                          opts->switch_to))
 314                 return -1;
 315
 316         if (get_revision_ranges(opts->upstream, opts->onto, &head_hash,
 317                                 &revisions, &shortrevisions))
 318                 return -1;
 319
 320         if (init_basic_state(&replay,
 321                              opts->head_name ? opts->head_name : "detached HEAD",
 322                              opts->onto, head_hash)) {
 323                 free(revisions);
 324                 free(shortrevisions);
 325
 326                 return -1;
 327         }
 328
 329         if (!opts->upstream && opts->squash_onto)
 330                 write_file(path_squash_onto(), "%s\n",
 331                            oid_to_hex(opts->squash_onto));
 332
 333         argv_array_pushl(&make_script_args, "", revisions, NULL);
 334         if (opts->restrict_revision)
 335                 argv_array_push(&make_script_args,
 336                                 oid_to_hex(&opts->restrict_revision->object.oid));
 337
 338         ret = sequencer_make_script(the_repository, &todo_list.buf,
 339                                     make_script_args.argc, make_script_args.argv,
 340                                     flags);
 341
 342         if (ret)
 343                 error(_("could not generate todo list"));
 344         else {
 345                 discard_cache();
 346                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 347                                                 &todo_list))
 348                         BUG("unusable todo list");
 349
 350                 split_exec_commands(opts->cmd, &commands);
 351                 ret = complete_action(the_repository, &replay, flags,
 352                         shortrevisions, opts->onto_name, opts->onto, head_hash,
 353                         &commands, opts->autosquash, &todo_list);
 354         }
 355
 356         string_list_clear(&commands, 0);
 357         free(revisions);
 358         free(shortrevisions);
 359         todo_list_release(&todo_list);
 360         argv_array_clear(&make_script_args);
 361
 362         return ret;
 363 }
 364
 365 static int run_rebase_interactive(struct rebase_options *opts,
 366                                   enum action command)
 367 {
 368         unsigned flags = 0;
 369         int abbreviate_commands = 0, ret = 0;
 370
 371         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 372
 373         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 374         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 375         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 376         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 377         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 378
 379         switch (command) {
 380         case ACTION_NONE: {
 381                 if (!opts->onto && !opts->upstream)
 382                         die(_("a base commit must be provided with --upstream or --onto"));
 383
 384                 ret = do_interactive_rebase(opts, flags);
 385                 break;
 386         }
 387         case ACTION_SKIP: {
 388                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 389
 390                 rerere_clear(the_repository, &merge_rr);
 391         }
 392                 /* fallthrough */
 393         case ACTION_CONTINUE: {
 394                 struct replay_opts replay_opts = get_replay_opts(opts);
 395
 396                 ret = sequencer_continue(the_repository, &replay_opts);
 397                 break;
 398         }
 399         case ACTION_EDIT_TODO:
 400                 ret = edit_todo_file(flags);
 401                 break;
 402         case ACTION_SHOW_CURRENT_PATCH: {
 403                 struct child_process cmd = CHILD_PROCESS_INIT;
 404
 405                 cmd.git_cmd = 1;
 406                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 407                 ret = run_command(&cmd);
 408
 409                 break;
 410         }
 411         case ACTION_SHORTEN_OIDS:
 412         case ACTION_EXPAND_OIDS:
 413                 ret = transform_todo_file(flags);
 414                 break;
 415         case ACTION_CHECK_TODO_LIST:
 416                 ret = check_todo_list_from_file(the_repository);
 417                 break;
 418         case ACTION_REARRANGE_SQUASH:
 419                 ret = rearrange_squash_in_todo_file();
 420                 break;
 421         case ACTION_ADD_EXEC: {
 422                 struct string_list commands = STRING_LIST_INIT_DUP;
 423
 424                 split_exec_commands(opts->cmd, &commands);
 425                 ret = add_exec_commands(&commands);
 426                 string_list_clear(&commands, 0);
 427                 break;
 428         }
 429         default:
 430                 BUG("invalid command '%d'", command);
 431         }
 432
 433         return ret;
 434 }
 435
 436 static const char * const builtin_rebase_interactive_usage[] = {
 437         N_("git rebase--interactive [<options>]"),
 438         NULL
 439 };
 440
 441 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 442 {
 443         struct rebase_options opts = REBASE_OPTIONS_INIT;
 444         struct object_id squash_onto = null_oid;
 445         enum action command = ACTION_NONE;
 446         struct option options[] = {
 447                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 448                            REBASE_FORCE),
 449                 OPT_BOOL(0, "keep-empty", &opts.keep_empty, N_("keep empty commits")),
 450                 OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
 451                          N_("allow commits with empty messages")),
 452                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 453                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 454                          N_("keep original branch points of cousins")),
 455                 OPT_BOOL(0, "autosquash", &opts.autosquash,
 456                          N_("move commits that begin with squash!/fixup!")),
 457                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 458                 OPT_BIT('v', "verbose", &opts.flags,
 459                         N_("display a diffstat of what changed upstream"),
 460                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 461                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 462                             ACTION_CONTINUE),
 463                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 464                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 465                             ACTION_EDIT_TODO),
 466                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 467                             ACTION_SHOW_CURRENT_PATCH),
 468                 OPT_CMDMODE(0, "shorten-ids", &command,
 469                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 470                 OPT_CMDMODE(0, "expand-ids", &command,
 471                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 472                 OPT_CMDMODE(0, "check-todo-list", &command,
 473                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 474                 OPT_CMDMODE(0, "rearrange-squash", &command,
 475                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 476                 OPT_CMDMODE(0, "add-exec-commands", &command,
 477                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 478                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 479                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 480                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 481                   N_("restrict-revision"), N_("restrict revision"),
 482                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 483                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 484                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 485                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 486                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 487                   0 },
 488                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 489                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 490                         N_("GPG-sign commits"),
 491                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 492                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 493                            N_("rebase strategy")),
 494                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 495                            N_("strategy options")),
 496                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 497                            N_("the branch or commit to checkout")),
 498                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 499                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 500                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 501                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 502                          N_("automatically re-schedule any `exec` that fails")),
 503                 OPT_END()
 504         };
 505
 506         opts.rebase_cousins = -1;
 507
 508         if (argc == 1)
 509                 usage_with_options(builtin_rebase_interactive_usage, options);
 510
 511         argc = parse_options(argc, argv, NULL, options,
 512                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 513
 514         if (!is_null_oid(&squash_onto))
 515                 opts.squash_onto = &squash_onto;
 516
 517         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 518                 warning(_("--[no-]rebase-cousins has no effect without "
 519                           "--rebase-merges"));
 520
 521         return !!run_rebase_interactive(&opts, command);
 522 }
 523
 524 static int is_interactive(struct rebase_options *opts)
 525 {
 526         return opts->type == REBASE_INTERACTIVE ||
 527                 opts->type == REBASE_PRESERVE_MERGES;
 528 }
 529
 530 static void imply_interactive(struct rebase_options *opts, const char *option)
 531 {
 532         switch (opts->type) {
 533         case REBASE_AM:
 534                 die(_("%s requires an interactive rebase"), option);
 535                 break;
 536         case REBASE_INTERACTIVE:
 537         case REBASE_PRESERVE_MERGES:
 538                 break;
 539         case REBASE_MERGE:
 540                 /* we now implement --merge via --interactive */
 541         default:
 542                 opts->type = REBASE_INTERACTIVE; /* implied */
 543                 break;
 544         }
 545 }
 546
 547 /* Returns the filename prefixed by the state_dir */
 548 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 549 {
 550         static struct strbuf path = STRBUF_INIT;
 551         static size_t prefix_len;
 552
 553         if (!prefix_len) {
 554                 strbuf_addf(&path, "%s/", opts->state_dir);
 555                 prefix_len = path.len;
 556         }
 557
 558         strbuf_setlen(&path, prefix_len);
 559         strbuf_addstr(&path, filename);
 560         return path.buf;
 561 }
 562
 563 /* Read one file, then strip line endings */
 564 static int read_one(const char *path, struct strbuf *buf)
 565 {
 566         if (strbuf_read_file(buf, path, 0) < 0)
 567                 return error_errno(_("could not read '%s'"), path);
 568         strbuf_trim_trailing_newline(buf);
 569         return 0;
 570 }
 571
 572 /* Initialize the rebase options from the state directory. */
 573 static int read_basic_state(struct rebase_options *opts)
 574 {
 575         struct strbuf head_name = STRBUF_INIT;
 576         struct strbuf buf = STRBUF_INIT;
 577         struct object_id oid;
 578
 579         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 580             read_one(state_dir_path("onto", opts), &buf))
 581                 return -1;
 582         opts->head_name = starts_with(head_name.buf, "refs/") ?
 583                 xstrdup(head_name.buf) : NULL;
 584         strbuf_release(&head_name);
 585         if (get_oid(buf.buf, &oid))
 586                 return error(_("could not get 'onto': '%s'"), buf.buf);
 587         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 588
 589         /*
 590          * We always write to orig-head, but interactive rebase used to write to
 591          * head. Fall back to reading from head to cover for the case that the
 592          * user upgraded git with an ongoing interactive rebase.
 593          */
 594         strbuf_reset(&buf);
 595         if (file_exists(state_dir_path("orig-head", opts))) {
 596                 if (read_one(state_dir_path("orig-head", opts), &buf))
 597                         return -1;
 598         } else if (read_one(state_dir_path("head", opts), &buf))
 599                 return -1;
 600         if (get_oid(buf.buf, &opts->orig_head))
 601                 return error(_("invalid orig-head: '%s'"), buf.buf);
 602
 603         if (file_exists(state_dir_path("quiet", opts)))
 604                 opts->flags &= ~REBASE_NO_QUIET;
 605         else
 606                 opts->flags |= REBASE_NO_QUIET;
 607
 608         if (file_exists(state_dir_path("verbose", opts)))
 609                 opts->flags |= REBASE_VERBOSE;
 610
 611         if (file_exists(state_dir_path("signoff", opts))) {
 612                 opts->signoff = 1;
 613                 opts->flags |= REBASE_FORCE;
 614         }
 615
 616         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 617                 strbuf_reset(&buf);
 618                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 619                             &buf))
 620                         return -1;
 621                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 622                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 623                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 624                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 625                 else
 626                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 627                                   "'%s'"), buf.buf);
 628         }
 629
 630         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 631                 strbuf_reset(&buf);
 632                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 633                             &buf))
 634                         return -1;
 635                 free(opts->gpg_sign_opt);
 636                 opts->gpg_sign_opt = xstrdup(buf.buf);
 637         }
 638
 639         if (file_exists(state_dir_path("strategy", opts))) {
 640                 strbuf_reset(&buf);
 641                 if (read_one(state_dir_path("strategy", opts), &buf))
 642                         return -1;
 643                 free(opts->strategy);
 644                 opts->strategy = xstrdup(buf.buf);
 645         }
 646
 647         if (file_exists(state_dir_path("strategy_opts", opts))) {
 648                 strbuf_reset(&buf);
 649                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 650                         return -1;
 651                 free(opts->strategy_opts);
 652                 opts->strategy_opts = xstrdup(buf.buf);
 653         }
 654
 655         strbuf_release(&buf);
 656
 657         return 0;
 658 }
 659
 660 static int rebase_write_basic_state(struct rebase_options *opts)
 661 {
 662         write_file(state_dir_path("head-name", opts), "%s",
 663                    opts->head_name ? opts->head_name : "detached HEAD");
 664         write_file(state_dir_path("onto", opts), "%s",
 665                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 666         write_file(state_dir_path("orig-head", opts), "%s",
 667                    oid_to_hex(&opts->orig_head));
 668         write_file(state_dir_path("quiet", opts), "%s",
 669                    opts->flags & REBASE_NO_QUIET ? "" : "t");
 670         if (opts->flags & REBASE_VERBOSE)
 671                 write_file(state_dir_path("verbose", opts), "%s", "");
 672         if (opts->strategy)
 673                 write_file(state_dir_path("strategy", opts), "%s",
 674                            opts->strategy);
 675         if (opts->strategy_opts)
 676                 write_file(state_dir_path("strategy_opts", opts), "%s",
 677                            opts->strategy_opts);
 678         if (opts->allow_rerere_autoupdate > 0)
 679                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 680                            "-%s-rerere-autoupdate",
 681                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 682                                 "" : "-no");
 683         if (opts->gpg_sign_opt)
 684                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 685                            opts->gpg_sign_opt);
 686         if (opts->signoff)
 687                 write_file(state_dir_path("strategy", opts), "--signoff");
 688
 689         return 0;
 690 }
 691
 692 static int apply_autostash(struct rebase_options *opts)
 693 {
 694         const char *path = state_dir_path("autostash", opts);
 695         struct strbuf autostash = STRBUF_INIT;
 696         struct child_process stash_apply = CHILD_PROCESS_INIT;
 697
 698         if (!file_exists(path))
 699                 return 0;
 700
 701         if (read_one(path, &autostash))
 702                 return error(_("Could not read '%s'"), path);
 703         /* Ensure that the hash is not mistaken for a number */
 704         strbuf_addstr(&autostash, "^0");
 705         argv_array_pushl(&stash_apply.args,
 706                          "stash", "apply", autostash.buf, NULL);
 707         stash_apply.git_cmd = 1;
 708         stash_apply.no_stderr = stash_apply.no_stdout =
 709                 stash_apply.no_stdin = 1;
 710         if (!run_command(&stash_apply))
 711                 printf(_("Applied autostash.\n"));
 712         else {
 713                 struct argv_array args = ARGV_ARRAY_INIT;
 714                 int res = 0;
 715
 716                 argv_array_pushl(&args,
 717                                  "stash", "store", "-m", "autostash", "-q",
 718                                  autostash.buf, NULL);
 719                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 720                         res = error(_("Cannot store %s"), autostash.buf);
 721                 argv_array_clear(&args);
 722                 strbuf_release(&autostash);
 723                 if (res)
 724                         return res;
 725
 726                 fprintf(stderr,
 727                         _("Applying autostash resulted in conflicts.\n"
 728                           "Your changes are safe in the stash.\n"
 729                           "You can run \"git stash pop\" or \"git stash drop\" "
 730                           "at any time.\n"));
 731         }
 732
 733         strbuf_release(&autostash);
 734         return 0;
 735 }
 736
 737 static int finish_rebase(struct rebase_options *opts)
 738 {
 739         struct strbuf dir = STRBUF_INIT;
 740         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 741         int ret = 0;
 742
 743         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 744         apply_autostash(opts);
 745         close_object_store(the_repository->objects);
 746         /*
 747          * We ignore errors in 'gc --auto', since the
 748          * user should see them.
 749          */
 750         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 751         if (opts->type == REBASE_INTERACTIVE) {
 752                 struct replay_opts replay = REPLAY_OPTS_INIT;
 753
 754                 replay.action = REPLAY_INTERACTIVE_REBASE;
 755                 ret = sequencer_remove_state(&replay);
 756         } else {
 757                 strbuf_addstr(&dir, opts->state_dir);
 758                 if (remove_dir_recursively(&dir, 0))
 759                         ret = error(_("could not remove '%s'"),
 760                                     opts->state_dir);
 761                 strbuf_release(&dir);
 762         }
 763
 764         return ret;
 765 }
 766
 767 static struct commit *peel_committish(const char *name)
 768 {
 769         struct object *obj;
 770         struct object_id oid;
 771
 772         if (get_oid(name, &oid))
 773                 return NULL;
 774         obj = parse_object(the_repository, &oid);
 775         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 776 }
 777
 778 static void add_var(struct strbuf *buf, const char *name, const char *value)
 779 {
 780         if (!value)
 781                 strbuf_addf(buf, "unset %s; ", name);
 782         else {
 783                 strbuf_addf(buf, "%s=", name);
 784                 sq_quote_buf(buf, value);
 785                 strbuf_addstr(buf, "; ");
 786         }
 787 }
 788
 789 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 790
 791 #define RESET_HEAD_DETACH (1<<0)
 792 #define RESET_HEAD_HARD (1<<1)
 793 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 794 #define RESET_HEAD_REFS_ONLY (1<<3)
 795 #define RESET_ORIG_HEAD (1<<4)
 796
 797 static int reset_head(struct object_id *oid, const char *action,
 798                       const char *switch_to_branch, unsigned flags,
 799                       const char *reflog_orig_head, const char *reflog_head)
 800 {
 801         unsigned detach_head = flags & RESET_HEAD_DETACH;
 802         unsigned reset_hard = flags & RESET_HEAD_HARD;
 803         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 804         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 805         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 806         struct object_id head_oid;
 807         struct tree_desc desc[2] = { { NULL }, { NULL } };
 808         struct lock_file lock = LOCK_INIT;
 809         struct unpack_trees_options unpack_tree_opts;
 810         struct tree *tree;
 811         const char *reflog_action;
 812         struct strbuf msg = STRBUF_INIT;
 813         size_t prefix_len;
 814         struct object_id *orig = NULL, oid_orig,
 815                 *old_orig = NULL, oid_old_orig;
 816         int ret = 0, nr = 0;
 817
 818         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 819                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 820
 821         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 822                 ret = -1;
 823                 goto leave_reset_head;
 824         }
 825
 826         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 827                 ret = error(_("could not determine HEAD revision"));
 828                 goto leave_reset_head;
 829         }
 830
 831         if (!oid)
 832                 oid = &head_oid;
 833
 834         if (refs_only)
 835                 goto reset_head_refs;
 836
 837         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 838         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 839         unpack_tree_opts.head_idx = 1;
 840         unpack_tree_opts.src_index = the_repository->index;
 841         unpack_tree_opts.dst_index = the_repository->index;
 842         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 843         unpack_tree_opts.update = 1;
 844         unpack_tree_opts.merge = 1;
 845         if (!detach_head)
 846                 unpack_tree_opts.reset = 1;
 847
 848         if (repo_read_index_unmerged(the_repository) < 0) {
 849                 ret = error(_("could not read index"));
 850                 goto leave_reset_head;
 851         }
 852
 853         if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
 854                 ret = error(_("failed to find tree of %s"),
 855                             oid_to_hex(&head_oid));
 856                 goto leave_reset_head;
 857         }
 858
 859         if (!fill_tree_descriptor(&desc[nr++], oid)) {
 860                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 861                 goto leave_reset_head;
 862         }
 863
 864         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 865                 ret = -1;
 866                 goto leave_reset_head;
 867         }
 868
 869         tree = parse_tree_indirect(oid);
 870         prime_cache_tree(the_repository, the_repository->index, tree);
 871
 872         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 873                 ret = error(_("could not write index"));
 874                 goto leave_reset_head;
 875         }
 876
 877 reset_head_refs:
 878         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 879         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 880         prefix_len = msg.len;
 881
 882         if (update_orig_head) {
 883                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 884                         old_orig = &oid_old_orig;
 885                 if (!get_oid("HEAD", &oid_orig)) {
 886                         orig = &oid_orig;
 887                         if (!reflog_orig_head) {
 888                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 889                                 reflog_orig_head = msg.buf;
 890                         }
 891                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 892                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 893                 } else if (old_orig)
 894                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 895         }
 896
 897         if (!reflog_head) {
 898                 strbuf_setlen(&msg, prefix_len);
 899                 strbuf_addstr(&msg, "updating HEAD");
 900                 reflog_head = msg.buf;
 901         }
 902         if (!switch_to_branch)
 903                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 904                                  detach_head ? REF_NO_DEREF : 0,
 905                                  UPDATE_REFS_MSG_ON_ERR);
 906         else {
 907                 ret = update_ref(reflog_head, switch_to_branch, oid,
 908                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 909                 if (!ret)
 910                         ret = create_symref("HEAD", switch_to_branch,
 911                                             reflog_head);
 912         }
 913         if (run_hook)
 914                 run_hook_le(NULL, "post-checkout",
 915                             oid_to_hex(orig ? orig : &null_oid),
 916                             oid_to_hex(oid), "1", NULL);
 917
 918 leave_reset_head:
 919         strbuf_release(&msg);
 920         rollback_lock_file(&lock);
 921         while (nr)
 922                 free((void *)desc[--nr].buffer);
 923         return ret;
 924 }
 925
 926 static int move_to_original_branch(struct rebase_options *opts)
 927 {
 928         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 929         int ret;
 930
 931         if (!opts->head_name)
 932                 return 0; /* nothing to move back to */
 933
 934         if (!opts->onto)
 935                 BUG("move_to_original_branch without onto");
 936
 937         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 938                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 939         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 940                     opts->head_name);
 941         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 942                          orig_head_reflog.buf, head_reflog.buf);
 943
 944         strbuf_release(&orig_head_reflog);
 945         strbuf_release(&head_reflog);
 946         return ret;
 947 }
 948
 949 static const char *resolvemsg =
 950 N_("Resolve all conflicts manually, mark them as resolved with\n"
 951 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 952 "You can instead skip this commit: run \"git rebase --skip\".\n"
 953 "To abort and get back to the state before \"git rebase\", run "
 954 "\"git rebase --abort\".");
 955
 956 static int run_am(struct rebase_options *opts)
 957 {
 958         struct child_process am = CHILD_PROCESS_INIT;
 959         struct child_process format_patch = CHILD_PROCESS_INIT;
 960         struct strbuf revisions = STRBUF_INIT;
 961         int status;
 962         char *rebased_patches;
 963
 964         am.git_cmd = 1;
 965         argv_array_push(&am.args, "am");
 966
 967         if (opts->action && !strcmp("continue", opts->action)) {
 968                 argv_array_push(&am.args, "--resolved");
 969                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 970                 if (opts->gpg_sign_opt)
 971                         argv_array_push(&am.args, opts->gpg_sign_opt);
 972                 status = run_command(&am);
 973                 if (status)
 974                         return status;
 975
 976                 return move_to_original_branch(opts);
 977         }
 978         if (opts->action && !strcmp("skip", opts->action)) {
 979                 argv_array_push(&am.args, "--skip");
 980                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 981                 status = run_command(&am);
 982                 if (status)
 983                         return status;
 984
 985                 return move_to_original_branch(opts);
 986         }
 987         if (opts->action && !strcmp("show-current-patch", opts->action)) {
 988                 argv_array_push(&am.args, "--show-current-patch");
 989                 return run_command(&am);
 990         }
 991
 992         strbuf_addf(&revisions, "%s...%s",
 993                     oid_to_hex(opts->root ?
 994                                /* this is now equivalent to !opts->upstream */
 995                                &opts->onto->object.oid :
 996                                &opts->upstream->object.oid),
 997                     oid_to_hex(&opts->orig_head));
 998
 999         rebased_patches = xstrdup(git_path("rebased-patches"));
1000         format_patch.out = open(rebased_patches,
1001                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1002         if (format_patch.out < 0) {
1003                 status = error_errno(_("could not open '%s' for writing"),
1004                                      rebased_patches);
1005                 free(rebased_patches);
1006                 argv_array_clear(&am.args);
1007                 return status;
1008         }
1009
1010         format_patch.git_cmd = 1;
1011         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1012                          "--full-index", "--cherry-pick", "--right-only",
1013                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1014                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
1015         if (opts->git_format_patch_opt.len)
1016                 argv_array_split(&format_patch.args,
1017                                  opts->git_format_patch_opt.buf);
1018         argv_array_push(&format_patch.args, revisions.buf);
1019         if (opts->restrict_revision)
1020                 argv_array_pushf(&format_patch.args, "^%s",
1021                                  oid_to_hex(&opts->restrict_revision->object.oid));
1022
1023         status = run_command(&format_patch);
1024         if (status) {
1025                 unlink(rebased_patches);
1026                 free(rebased_patches);
1027                 argv_array_clear(&am.args);
1028
1029                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1030                            "HEAD", NULL);
1031                 error(_("\ngit encountered an error while preparing the "
1032                         "patches to replay\n"
1033                         "these revisions:\n"
1034                         "\n    %s\n\n"
1035                         "As a result, git cannot rebase them."),
1036                       opts->revisions);
1037
1038                 strbuf_release(&revisions);
1039                 return status;
1040         }
1041         strbuf_release(&revisions);
1042
1043         am.in = open(rebased_patches, O_RDONLY);
1044         if (am.in < 0) {
1045                 status = error_errno(_("could not open '%s' for reading"),
1046                                      rebased_patches);
1047                 free(rebased_patches);
1048                 argv_array_clear(&am.args);
1049                 return status;
1050         }
1051
1052         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1053         argv_array_push(&am.args, "--rebasing");
1054         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1055         argv_array_push(&am.args, "--patch-format=mboxrd");
1056         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1057                 argv_array_push(&am.args, "--rerere-autoupdate");
1058         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1059                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1060         if (opts->gpg_sign_opt)
1061                 argv_array_push(&am.args, opts->gpg_sign_opt);
1062         status = run_command(&am);
1063         unlink(rebased_patches);
1064         free(rebased_patches);
1065
1066         if (!status) {
1067                 return move_to_original_branch(opts);
1068         }
1069
1070         if (is_directory(opts->state_dir))
1071                 rebase_write_basic_state(opts);
1072
1073         return status;
1074 }
1075
1076 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1077 {
1078         const char *argv[] = { NULL, NULL };
1079         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1080         int status;
1081         const char *backend, *backend_func;
1082
1083         if (opts->type == REBASE_INTERACTIVE) {
1084                 /* Run builtin interactive rebase */
1085                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1086                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1087                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1088                         opts->autosquash = 0;
1089                 }
1090                 if (opts->gpg_sign_opt) {
1091                         /* remove the leading "-S" */
1092                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1093                         free(opts->gpg_sign_opt);
1094                         opts->gpg_sign_opt = tmp;
1095                 }
1096
1097                 status = run_rebase_interactive(opts, action);
1098                 goto finished_rebase;
1099         }
1100
1101         if (opts->type == REBASE_AM) {
1102                 status = run_am(opts);
1103                 goto finished_rebase;
1104         }
1105
1106         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1107         add_var(&script_snippet, "state_dir", opts->state_dir);
1108
1109         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1110         add_var(&script_snippet, "upstream", opts->upstream ?
1111                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1112         add_var(&script_snippet, "head_name",
1113                 opts->head_name ? opts->head_name : "detached HEAD");
1114         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1115         add_var(&script_snippet, "onto", opts->onto ?
1116                 oid_to_hex(&opts->onto->object.oid) : NULL);
1117         add_var(&script_snippet, "onto_name", opts->onto_name);
1118         add_var(&script_snippet, "revisions", opts->revisions);
1119         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1120                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1121         add_var(&script_snippet, "GIT_QUIET",
1122                 opts->flags & REBASE_NO_QUIET ? "" : "t");
1123         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1124         add_var(&script_snippet, "git_am_opt", buf.buf);
1125         strbuf_release(&buf);
1126         add_var(&script_snippet, "verbose",
1127                 opts->flags & REBASE_VERBOSE ? "t" : "");
1128         add_var(&script_snippet, "diffstat",
1129                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1130         add_var(&script_snippet, "force_rebase",
1131                 opts->flags & REBASE_FORCE ? "t" : "");
1132         if (opts->switch_to)
1133                 add_var(&script_snippet, "switch_to", opts->switch_to);
1134         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1135         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1136         add_var(&script_snippet, "allow_rerere_autoupdate",
1137                 opts->allow_rerere_autoupdate ?
1138                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1139                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1140         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1141         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1142         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1143         add_var(&script_snippet, "cmd", opts->cmd);
1144         add_var(&script_snippet, "allow_empty_message",
1145                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1146         add_var(&script_snippet, "rebase_merges",
1147                 opts->rebase_merges ? "t" : "");
1148         add_var(&script_snippet, "rebase_cousins",
1149                 opts->rebase_cousins ? "t" : "");
1150         add_var(&script_snippet, "strategy", opts->strategy);
1151         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1152         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1153         add_var(&script_snippet, "squash_onto",
1154                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1155         add_var(&script_snippet, "git_format_patch_opt",
1156                 opts->git_format_patch_opt.buf);
1157
1158         if (is_interactive(opts) &&
1159             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1160                 strbuf_addstr(&script_snippet,
1161                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1162                 opts->autosquash = 0;
1163         }
1164
1165         switch (opts->type) {
1166         case REBASE_AM:
1167                 backend = "git-rebase--am";
1168                 backend_func = "git_rebase__am";
1169                 break;
1170         case REBASE_PRESERVE_MERGES:
1171                 backend = "git-rebase--preserve-merges";
1172                 backend_func = "git_rebase__preserve_merges";
1173                 break;
1174         default:
1175                 BUG("Unhandled rebase type %d", opts->type);
1176                 break;
1177         }
1178
1179         strbuf_addf(&script_snippet,
1180                     ". git-sh-setup && . git-rebase--common &&"
1181                     " . %s && %s", backend, backend_func);
1182         argv[0] = script_snippet.buf;
1183
1184         status = run_command_v_opt(argv, RUN_USING_SHELL);
1185 finished_rebase:
1186         if (opts->dont_finish_rebase)
1187                 ; /* do nothing */
1188         else if (opts->type == REBASE_INTERACTIVE)
1189                 ; /* interactive rebase cleans up after itself */
1190         else if (status == 0) {
1191                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1192                         finish_rebase(opts);
1193         } else if (status == 2) {
1194                 struct strbuf dir = STRBUF_INIT;
1195
1196                 apply_autostash(opts);
1197                 strbuf_addstr(&dir, opts->state_dir);
1198                 remove_dir_recursively(&dir, 0);
1199                 strbuf_release(&dir);
1200                 die("Nothing to do");
1201         }
1202
1203         strbuf_release(&script_snippet);
1204
1205         return status ? -1 : 0;
1206 }
1207
1208 static int rebase_config(const char *var, const char *value, void *data)
1209 {
1210         struct rebase_options *opts = data;
1211
1212         if (!strcmp(var, "rebase.stat")) {
1213                 if (git_config_bool(var, value))
1214                         opts->flags |= REBASE_DIFFSTAT;
1215                 else
1216                         opts->flags &= ~REBASE_DIFFSTAT;
1217                 return 0;
1218         }
1219
1220         if (!strcmp(var, "rebase.autosquash")) {
1221                 opts->autosquash = git_config_bool(var, value);
1222                 return 0;
1223         }
1224
1225         if (!strcmp(var, "commit.gpgsign")) {
1226                 free(opts->gpg_sign_opt);
1227                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1228                         xstrdup("-S") : NULL;
1229                 return 0;
1230         }
1231
1232         if (!strcmp(var, "rebase.autostash")) {
1233                 opts->autostash = git_config_bool(var, value);
1234                 return 0;
1235         }
1236
1237         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1238                 opts->reschedule_failed_exec = git_config_bool(var, value);
1239                 return 0;
1240         }
1241
1242         if (!strcmp(var, "rebase.usebuiltin")) {
1243                 opts->use_legacy_rebase = !git_config_bool(var, value);
1244                 return 0;
1245         }
1246
1247         return git_default_config(var, value, data);
1248 }
1249
1250 /*
1251  * Determines whether the commits in from..to are linear, i.e. contain
1252  * no merge commits. This function *expects* `from` to be an ancestor of
1253  * `to`.
1254  */
1255 static int is_linear_history(struct commit *from, struct commit *to)
1256 {
1257         while (to && to != from) {
1258                 parse_commit(to);
1259                 if (!to->parents)
1260                         return 1;
1261                 if (to->parents->next)
1262                         return 0;
1263                 to = to->parents->item;
1264         }
1265         return 1;
1266 }
1267
1268 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
1269                             struct object_id *merge_base)
1270 {
1271         struct commit *head = lookup_commit(the_repository, head_oid);
1272         struct commit_list *merge_bases;
1273         int res;
1274
1275         if (!head)
1276                 return 0;
1277
1278         merge_bases = get_merge_bases(onto, head);
1279         if (merge_bases && !merge_bases->next) {
1280                 oidcpy(merge_base, &merge_bases->item->object.oid);
1281                 res = oideq(merge_base, &onto->object.oid);
1282         } else {
1283                 oidcpy(merge_base, &null_oid);
1284                 res = 0;
1285         }
1286         free_commit_list(merge_bases);
1287         return res && is_linear_history(onto, head);
1288 }
1289
1290 /* -i followed by -m is still -i */
1291 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1292 {
1293         struct rebase_options *opts = opt->value;
1294
1295         BUG_ON_OPT_NEG(unset);
1296         BUG_ON_OPT_ARG(arg);
1297
1298         if (!is_interactive(opts))
1299                 opts->type = REBASE_MERGE;
1300
1301         return 0;
1302 }
1303
1304 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1305 static int parse_opt_interactive(const struct option *opt, const char *arg,
1306                                  int unset)
1307 {
1308         struct rebase_options *opts = opt->value;
1309
1310         BUG_ON_OPT_NEG(unset);
1311         BUG_ON_OPT_ARG(arg);
1312
1313         opts->type = REBASE_INTERACTIVE;
1314         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1315
1316         return 0;
1317 }
1318
1319 static void NORETURN error_on_missing_default_upstream(void)
1320 {
1321         struct branch *current_branch = branch_get(NULL);
1322
1323         printf(_("%s\n"
1324                  "Please specify which branch you want to rebase against.\n"
1325                  "See git-rebase(1) for details.\n"
1326                  "\n"
1327                  "    git rebase '<branch>'\n"
1328                  "\n"),
1329                 current_branch ? _("There is no tracking information for "
1330                         "the current branch.") :
1331                         _("You are not currently on a branch."));
1332
1333         if (current_branch) {
1334                 const char *remote = current_branch->remote_name;
1335
1336                 if (!remote)
1337                         remote = _("<remote>");
1338
1339                 printf(_("If you wish to set tracking information for this "
1340                          "branch you can do so with:\n"
1341                          "\n"
1342                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1343                          "\n"),
1344                        remote, current_branch->name);
1345         }
1346         exit(1);
1347 }
1348
1349 static void set_reflog_action(struct rebase_options *options)
1350 {
1351         const char *env;
1352         struct strbuf buf = STRBUF_INIT;
1353
1354         if (!is_interactive(options))
1355                 return;
1356
1357         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1358         if (env && strcmp("rebase", env))
1359                 return; /* only override it if it is "rebase" */
1360
1361         strbuf_addf(&buf, "rebase -i (%s)", options->action);
1362         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1363         strbuf_release(&buf);
1364 }
1365
1366 static int check_exec_cmd(const char *cmd)
1367 {
1368         if (strchr(cmd, '\n'))
1369                 return error(_("exec commands cannot contain newlines"));
1370
1371         /* Does the command consist purely of whitespace? */
1372         if (!cmd[strspn(cmd, " \t\r\f\v")])
1373                 return error(_("empty exec command"));
1374
1375         return 0;
1376 }
1377
1378
1379 int cmd_rebase(int argc, const char **argv, const char *prefix)
1380 {
1381         struct rebase_options options = REBASE_OPTIONS_INIT;
1382         const char *branch_name;
1383         int ret, flags, total_argc, in_progress = 0;
1384         int ok_to_skip_pre_rebase = 0;
1385         struct strbuf msg = STRBUF_INIT;
1386         struct strbuf revisions = STRBUF_INIT;
1387         struct strbuf buf = STRBUF_INIT;
1388         struct object_id merge_base;
1389         enum action action = ACTION_NONE;
1390         const char *gpg_sign = NULL;
1391         struct string_list exec = STRING_LIST_INIT_NODUP;
1392         const char *rebase_merges = NULL;
1393         int fork_point = -1;
1394         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1395         struct object_id squash_onto;
1396         char *squash_onto_name = NULL;
1397         int reschedule_failed_exec = -1;
1398         struct option builtin_rebase_options[] = {
1399                 OPT_STRING(0, "onto", &options.onto_name,
1400                            N_("revision"),
1401                            N_("rebase onto given branch instead of upstream")),
1402                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1403                          N_("allow pre-rebase hook to run")),
1404                 OPT_NEGBIT('q', "quiet", &options.flags,
1405                            N_("be quiet. implies --no-stat"),
1406                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1407                 OPT_BIT('v', "verbose", &options.flags,
1408                         N_("display a diffstat of what changed upstream"),
1409                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1410                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1411                         N_("do not show diffstat of what changed upstream"),
1412                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1413                 OPT_BOOL(0, "signoff", &options.signoff,
1414                          N_("add a Signed-off-by: line to each commit")),
1415                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1416                                   NULL, N_("passed to 'git am'"),
1417                                   PARSE_OPT_NOARG),
1418                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1419                                   &options.git_am_opts, NULL,
1420                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1421                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1422                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1423                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1424                                   N_("passed to 'git apply'"), 0),
1425                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1426                                   N_("action"), N_("passed to 'git apply'"), 0),
1427                 OPT_BIT('f', "force-rebase", &options.flags,
1428                         N_("cherry-pick all commits, even if unchanged"),
1429                         REBASE_FORCE),
1430                 OPT_BIT(0, "no-ff", &options.flags,
1431                         N_("cherry-pick all commits, even if unchanged"),
1432                         REBASE_FORCE),
1433                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1434                             ACTION_CONTINUE),
1435                 OPT_CMDMODE(0, "skip", &action,
1436                             N_("skip current patch and continue"), ACTION_SKIP),
1437                 OPT_CMDMODE(0, "abort", &action,
1438                             N_("abort and check out the original branch"),
1439                             ACTION_ABORT),
1440                 OPT_CMDMODE(0, "quit", &action,
1441                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1442                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1443                             "during an interactive rebase"), ACTION_EDIT_TODO),
1444                 OPT_CMDMODE(0, "show-current-patch", &action,
1445                             N_("show the patch file being applied or merged"),
1446                             ACTION_SHOW_CURRENT_PATCH),
1447                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1448                         N_("use merging strategies to rebase"),
1449                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1450                         parse_opt_merge },
1451                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1452                         N_("let the user edit the list of commits to rebase"),
1453                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1454                         parse_opt_interactive },
1455                 OPT_SET_INT('p', "preserve-merges", &options.type,
1456                             N_("(DEPRECATED) try to recreate merges instead of "
1457                                "ignoring them"), REBASE_PRESERVE_MERGES),
1458                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1459                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
1460                          N_("preserve empty commits during rebase")),
1461                 OPT_BOOL(0, "autosquash", &options.autosquash,
1462                          N_("move commits that begin with "
1463                             "squash!/fixup! under -i")),
1464                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1465                         N_("GPG-sign commits"),
1466                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1467                 OPT_BOOL(0, "autostash", &options.autostash,
1468                          N_("automatically stash/stash pop before and after")),
1469                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1470                                 N_("add exec lines after each commit of the "
1471                                    "editable list")),
1472                 OPT_BOOL(0, "allow-empty-message",
1473                          &options.allow_empty_message,
1474                          N_("allow rebasing commits with empty messages")),
1475                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1476                         N_("mode"),
1477                         N_("try to rebase merges instead of skipping them"),
1478                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1479                 OPT_BOOL(0, "fork-point", &fork_point,
1480                          N_("use 'merge-base --fork-point' to refine upstream")),
1481                 OPT_STRING('s', "strategy", &options.strategy,
1482                            N_("strategy"), N_("use the given merge strategy")),
1483                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1484                                 N_("option"),
1485                                 N_("pass the argument through to the merge "
1486                                    "strategy")),
1487                 OPT_BOOL(0, "root", &options.root,
1488                          N_("rebase all reachable commits up to the root(s)")),
1489                 OPT_BOOL(0, "reschedule-failed-exec",
1490                          &reschedule_failed_exec,
1491                          N_("automatically re-schedule any `exec` that fails")),
1492                 OPT_END(),
1493         };
1494         int i;
1495
1496         if (argc == 2 && !strcmp(argv[1], "-h"))
1497                 usage_with_options(builtin_rebase_usage,
1498                                    builtin_rebase_options);
1499
1500         prefix = setup_git_directory();
1501         trace_repo_setup(prefix);
1502         setup_work_tree();
1503
1504         options.allow_empty_message = 1;
1505         git_config(rebase_config, &options);
1506
1507         if (options.use_legacy_rebase ||
1508             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1509                 warning(_("the rebase.useBuiltin support has been removed!\n"
1510                           "See its entry in 'git help config' for details."));
1511
1512         strbuf_reset(&buf);
1513         strbuf_addf(&buf, "%s/applying", apply_dir());
1514         if(file_exists(buf.buf))
1515                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1516
1517         if (is_directory(apply_dir())) {
1518                 options.type = REBASE_AM;
1519                 options.state_dir = apply_dir();
1520         } else if (is_directory(merge_dir())) {
1521                 strbuf_reset(&buf);
1522                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1523                 if (is_directory(buf.buf)) {
1524                         options.type = REBASE_PRESERVE_MERGES;
1525                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1526                 } else {
1527                         strbuf_reset(&buf);
1528                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1529                         if(file_exists(buf.buf)) {
1530                                 options.type = REBASE_INTERACTIVE;
1531                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1532                         } else
1533                                 options.type = REBASE_MERGE;
1534                 }
1535                 options.state_dir = merge_dir();
1536         }
1537
1538         if (options.type != REBASE_UNSPECIFIED)
1539                 in_progress = 1;
1540
1541         total_argc = argc;
1542         argc = parse_options(argc, argv, prefix,
1543                              builtin_rebase_options,
1544                              builtin_rebase_usage, 0);
1545
1546         if (action != ACTION_NONE && total_argc != 2) {
1547                 usage_with_options(builtin_rebase_usage,
1548                                    builtin_rebase_options);
1549         }
1550
1551         if (argc > 2)
1552                 usage_with_options(builtin_rebase_usage,
1553                                    builtin_rebase_options);
1554
1555         if (options.type == REBASE_PRESERVE_MERGES)
1556                 warning(_("git rebase --preserve-merges is deprecated. "
1557                           "Use --rebase-merges instead."));
1558
1559         if (action != ACTION_NONE && !in_progress)
1560                 die(_("No rebase in progress?"));
1561         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1562
1563         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1564                 die(_("The --edit-todo action can only be used during "
1565                       "interactive rebase."));
1566
1567         if (trace2_is_enabled()) {
1568                 if (is_interactive(&options))
1569                         trace2_cmd_mode("interactive");
1570                 else if (exec.nr)
1571                         trace2_cmd_mode("interactive-exec");
1572                 else
1573                         trace2_cmd_mode(action_names[action]);
1574         }
1575
1576         switch (action) {
1577         case ACTION_CONTINUE: {
1578                 struct object_id head;
1579                 struct lock_file lock_file = LOCK_INIT;
1580                 int fd;
1581
1582                 options.action = "continue";
1583                 set_reflog_action(&options);
1584
1585                 /* Sanity check */
1586                 if (get_oid("HEAD", &head))
1587                         die(_("Cannot read HEAD"));
1588
1589                 fd = hold_locked_index(&lock_file, 0);
1590                 if (repo_read_index(the_repository) < 0)
1591                         die(_("could not read index"));
1592                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1593                               NULL);
1594                 if (0 <= fd)
1595                         repo_update_index_if_able(the_repository, &lock_file);
1596                 rollback_lock_file(&lock_file);
1597
1598                 if (has_unstaged_changes(the_repository, 1)) {
1599                         puts(_("You must edit all merge conflicts and then\n"
1600                                "mark them as resolved using git add"));
1601                         exit(1);
1602                 }
1603                 if (read_basic_state(&options))
1604                         exit(1);
1605                 goto run_rebase;
1606         }
1607         case ACTION_SKIP: {
1608                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1609
1610                 options.action = "skip";
1611                 set_reflog_action(&options);
1612
1613                 rerere_clear(the_repository, &merge_rr);
1614                 string_list_clear(&merge_rr, 1);
1615
1616                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1617                                NULL, NULL) < 0)
1618                         die(_("could not discard worktree changes"));
1619                 remove_branch_state(the_repository);
1620                 if (read_basic_state(&options))
1621                         exit(1);
1622                 goto run_rebase;
1623         }
1624         case ACTION_ABORT: {
1625                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1626                 options.action = "abort";
1627                 set_reflog_action(&options);
1628
1629                 rerere_clear(the_repository, &merge_rr);
1630                 string_list_clear(&merge_rr, 1);
1631
1632                 if (read_basic_state(&options))
1633                         exit(1);
1634                 if (reset_head(&options.orig_head, "reset",
1635                                options.head_name, RESET_HEAD_HARD,
1636                                NULL, NULL) < 0)
1637                         die(_("could not move back to %s"),
1638                             oid_to_hex(&options.orig_head));
1639                 remove_branch_state(the_repository);
1640                 ret = !!finish_rebase(&options);
1641                 goto cleanup;
1642         }
1643         case ACTION_QUIT: {
1644                 if (options.type == REBASE_INTERACTIVE) {
1645                         struct replay_opts replay = REPLAY_OPTS_INIT;
1646
1647                         replay.action = REPLAY_INTERACTIVE_REBASE;
1648                         ret = !!sequencer_remove_state(&replay);
1649                 } else {
1650                         strbuf_reset(&buf);
1651                         strbuf_addstr(&buf, options.state_dir);
1652                         ret = !!remove_dir_recursively(&buf, 0);
1653                         if (ret)
1654                                 error(_("could not remove '%s'"),
1655                                        options.state_dir);
1656                 }
1657                 goto cleanup;
1658         }
1659         case ACTION_EDIT_TODO:
1660                 options.action = "edit-todo";
1661                 options.dont_finish_rebase = 1;
1662                 goto run_rebase;
1663         case ACTION_SHOW_CURRENT_PATCH:
1664                 options.action = "show-current-patch";
1665                 options.dont_finish_rebase = 1;
1666                 goto run_rebase;
1667         case ACTION_NONE:
1668                 break;
1669         default:
1670                 BUG("action: %d", action);
1671         }
1672
1673         /* Make sure no rebase is in progress */
1674         if (in_progress) {
1675                 const char *last_slash = strrchr(options.state_dir, '/');
1676                 const char *state_dir_base =
1677                         last_slash ? last_slash + 1 : options.state_dir;
1678                 const char *cmd_live_rebase =
1679                         "git rebase (--continue | --abort | --skip)";
1680                 strbuf_reset(&buf);
1681                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1682                 die(_("It seems that there is already a %s directory, and\n"
1683                       "I wonder if you are in the middle of another rebase.  "
1684                       "If that is the\n"
1685                       "case, please try\n\t%s\n"
1686                       "If that is not the case, please\n\t%s\n"
1687                       "and run me again.  I am stopping in case you still "
1688                       "have something\n"
1689                       "valuable there.\n"),
1690                     state_dir_base, cmd_live_rebase, buf.buf);
1691         }
1692
1693         for (i = 0; i < options.git_am_opts.argc; i++) {
1694                 const char *option = options.git_am_opts.argv[i], *p;
1695                 if (!strcmp(option, "--committer-date-is-author-date") ||
1696                     !strcmp(option, "--ignore-date") ||
1697                     !strcmp(option, "--whitespace=fix") ||
1698                     !strcmp(option, "--whitespace=strip"))
1699                         options.flags |= REBASE_FORCE;
1700                 else if (skip_prefix(option, "-C", &p)) {
1701                         while (*p)
1702                                 if (!isdigit(*(p++)))
1703                                         die(_("switch `C' expects a "
1704                                               "numerical value"));
1705                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1706                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1707                             strcmp(p, "error") && strcmp(p, "error-all"))
1708                                 die("Invalid whitespace option: '%s'", p);
1709                 }
1710         }
1711
1712         for (i = 0; i < exec.nr; i++)
1713                 if (check_exec_cmd(exec.items[i].string))
1714                         exit(1);
1715
1716         if (!(options.flags & REBASE_NO_QUIET))
1717                 argv_array_push(&options.git_am_opts, "-q");
1718
1719         if (options.keep_empty)
1720                 imply_interactive(&options, "--keep-empty");
1721
1722         if (gpg_sign) {
1723                 free(options.gpg_sign_opt);
1724                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1725         }
1726
1727         if (exec.nr) {
1728                 int i;
1729
1730                 imply_interactive(&options, "--exec");
1731
1732                 strbuf_reset(&buf);
1733                 for (i = 0; i < exec.nr; i++)
1734                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1735                 options.cmd = xstrdup(buf.buf);
1736         }
1737
1738         if (rebase_merges) {
1739                 if (!*rebase_merges)
1740                         ; /* default mode; do nothing */
1741                 else if (!strcmp("rebase-cousins", rebase_merges))
1742                         options.rebase_cousins = 1;
1743                 else if (strcmp("no-rebase-cousins", rebase_merges))
1744                         die(_("Unknown mode: %s"), rebase_merges);
1745                 options.rebase_merges = 1;
1746                 imply_interactive(&options, "--rebase-merges");
1747         }
1748
1749         if (strategy_options.nr) {
1750                 int i;
1751
1752                 if (!options.strategy)
1753                         options.strategy = "recursive";
1754
1755                 strbuf_reset(&buf);
1756                 for (i = 0; i < strategy_options.nr; i++)
1757                         strbuf_addf(&buf, " --%s",
1758                                     strategy_options.items[i].string);
1759                 options.strategy_opts = xstrdup(buf.buf);
1760         }
1761
1762         if (options.strategy) {
1763                 options.strategy = xstrdup(options.strategy);
1764                 switch (options.type) {
1765                 case REBASE_AM:
1766                         die(_("--strategy requires --merge or --interactive"));
1767                 case REBASE_MERGE:
1768                 case REBASE_INTERACTIVE:
1769                 case REBASE_PRESERVE_MERGES:
1770                         /* compatible */
1771                         break;
1772                 case REBASE_UNSPECIFIED:
1773                         options.type = REBASE_MERGE;
1774                         break;
1775                 default:
1776                         BUG("unhandled rebase type (%d)", options.type);
1777                 }
1778         }
1779
1780         if (options.type == REBASE_MERGE)
1781                 imply_interactive(&options, "--merge");
1782
1783         if (options.root && !options.onto_name)
1784                 imply_interactive(&options, "--root without --onto");
1785
1786         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1787                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1788
1789         switch (options.type) {
1790         case REBASE_MERGE:
1791         case REBASE_INTERACTIVE:
1792         case REBASE_PRESERVE_MERGES:
1793                 options.state_dir = merge_dir();
1794                 break;
1795         case REBASE_AM:
1796                 options.state_dir = apply_dir();
1797                 break;
1798         default:
1799                 /* the default rebase backend is `--am` */
1800                 options.type = REBASE_AM;
1801                 options.state_dir = apply_dir();
1802                 break;
1803         }
1804
1805         if (reschedule_failed_exec > 0 && !is_interactive(&options))
1806                 die(_("--reschedule-failed-exec requires "
1807                       "--exec or --interactive"));
1808         if (reschedule_failed_exec >= 0)
1809                 options.reschedule_failed_exec = reschedule_failed_exec;
1810
1811         if (options.git_am_opts.argc) {
1812                 /* all am options except -q are compatible only with --am */
1813                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1814                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1815                                 break;
1816
1817                 if (is_interactive(&options) && i >= 0)
1818                         die(_("cannot combine am options with either "
1819                               "interactive or merge options"));
1820         }
1821
1822         if (options.signoff) {
1823                 if (options.type == REBASE_PRESERVE_MERGES)
1824                         die("cannot combine '--signoff' with "
1825                             "'--preserve-merges'");
1826                 argv_array_push(&options.git_am_opts, "--signoff");
1827                 options.flags |= REBASE_FORCE;
1828         }
1829
1830         if (options.type == REBASE_PRESERVE_MERGES) {
1831                 /*
1832                  * Note: incompatibility with --signoff handled in signoff block above
1833                  * Note: incompatibility with --interactive is just a strong warning;
1834                  *       git-rebase.txt caveats with "unless you know what you are doing"
1835                  */
1836                 if (options.rebase_merges)
1837                         die(_("cannot combine '--preserve-merges' with "
1838                               "'--rebase-merges'"));
1839
1840                 if (options.reschedule_failed_exec)
1841                         die(_("error: cannot combine '--preserve-merges' with "
1842                               "'--reschedule-failed-exec'"));
1843         }
1844
1845         if (options.rebase_merges) {
1846                 if (strategy_options.nr)
1847                         die(_("cannot combine '--rebase-merges' with "
1848                               "'--strategy-option'"));
1849                 if (options.strategy)
1850                         die(_("cannot combine '--rebase-merges' with "
1851                               "'--strategy'"));
1852         }
1853
1854         if (!options.root) {
1855                 if (argc < 1) {
1856                         struct branch *branch;
1857
1858                         branch = branch_get(NULL);
1859                         options.upstream_name = branch_get_upstream(branch,
1860                                                                     NULL);
1861                         if (!options.upstream_name)
1862                                 error_on_missing_default_upstream();
1863                         if (fork_point < 0)
1864                                 fork_point = 1;
1865                 } else {
1866                         options.upstream_name = argv[0];
1867                         argc--;
1868                         argv++;
1869                         if (!strcmp(options.upstream_name, "-"))
1870                                 options.upstream_name = "@{-1}";
1871                 }
1872                 options.upstream = peel_committish(options.upstream_name);
1873                 if (!options.upstream)
1874                         die(_("invalid upstream '%s'"), options.upstream_name);
1875                 options.upstream_arg = options.upstream_name;
1876         } else {
1877                 if (!options.onto_name) {
1878                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1879                                         &squash_onto, NULL, NULL) < 0)
1880                                 die(_("Could not create new root commit"));
1881                         options.squash_onto = &squash_onto;
1882                         options.onto_name = squash_onto_name =
1883                                 xstrdup(oid_to_hex(&squash_onto));
1884                 }
1885                 options.upstream_name = NULL;
1886                 options.upstream = NULL;
1887                 if (argc > 1)
1888                         usage_with_options(builtin_rebase_usage,
1889                                            builtin_rebase_options);
1890                 options.upstream_arg = "--root";
1891         }
1892
1893         /* Make sure the branch to rebase onto is valid. */
1894         if (!options.onto_name)
1895                 options.onto_name = options.upstream_name;
1896         if (strstr(options.onto_name, "...")) {
1897                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
1898                         die(_("'%s': need exactly one merge base"),
1899                             options.onto_name);
1900                 options.onto = lookup_commit_or_die(&merge_base,
1901                                                     options.onto_name);
1902         } else {
1903                 options.onto = peel_committish(options.onto_name);
1904                 if (!options.onto)
1905                         die(_("Does not point to a valid commit '%s'"),
1906                                 options.onto_name);
1907         }
1908
1909         /*
1910          * If the branch to rebase is given, that is the branch we will rebase
1911          * branch_name -- branch/commit being rebased, or
1912          *                HEAD (already detached)
1913          * orig_head -- commit object name of tip of the branch before rebasing
1914          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1915          */
1916         if (argc == 1) {
1917                 /* Is it "rebase other branchname" or "rebase other commit"? */
1918                 branch_name = argv[0];
1919                 options.switch_to = argv[0];
1920
1921                 /* Is it a local branch? */
1922                 strbuf_reset(&buf);
1923                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1924                 if (!read_ref(buf.buf, &options.orig_head))
1925                         options.head_name = xstrdup(buf.buf);
1926                 /* If not is it a valid ref (branch or commit)? */
1927                 else if (!get_oid(branch_name, &options.orig_head))
1928                         options.head_name = NULL;
1929                 else
1930                         die(_("fatal: no such branch/commit '%s'"),
1931                             branch_name);
1932         } else if (argc == 0) {
1933                 /* Do not need to switch branches, we are already on it. */
1934                 options.head_name =
1935                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1936                                          &flags));
1937                 if (!options.head_name)
1938                         die(_("No such ref: %s"), "HEAD");
1939                 if (flags & REF_ISSYMREF) {
1940                         if (!skip_prefix(options.head_name,
1941                                          "refs/heads/", &branch_name))
1942                                 branch_name = options.head_name;
1943
1944                 } else {
1945                         FREE_AND_NULL(options.head_name);
1946                         branch_name = "HEAD";
1947                 }
1948                 if (get_oid("HEAD", &options.orig_head))
1949                         die(_("Could not resolve HEAD to a revision"));
1950         } else
1951                 BUG("unexpected number of arguments left to parse");
1952
1953         if (fork_point > 0) {
1954                 struct commit *head =
1955                         lookup_commit_reference(the_repository,
1956                                                 &options.orig_head);
1957                 options.restrict_revision =
1958                         get_fork_point(options.upstream_name, head);
1959         }
1960
1961         if (repo_read_index(the_repository) < 0)
1962                 die(_("could not read index"));
1963
1964         if (options.autostash) {
1965                 struct lock_file lock_file = LOCK_INIT;
1966                 int fd;
1967
1968                 fd = hold_locked_index(&lock_file, 0);
1969                 refresh_cache(REFRESH_QUIET);
1970                 if (0 <= fd)
1971                         repo_update_index_if_able(the_repository, &lock_file);
1972                 rollback_lock_file(&lock_file);
1973
1974                 if (has_unstaged_changes(the_repository, 1) ||
1975                     has_uncommitted_changes(the_repository, 1)) {
1976                         const char *autostash =
1977                                 state_dir_path("autostash", &options);
1978                         struct child_process stash = CHILD_PROCESS_INIT;
1979                         struct object_id oid;
1980                         struct commit *head =
1981                                 lookup_commit_reference(the_repository,
1982                                                         &options.orig_head);
1983
1984                         argv_array_pushl(&stash.args,
1985                                          "stash", "create", "autostash", NULL);
1986                         stash.git_cmd = 1;
1987                         stash.no_stdin = 1;
1988                         strbuf_reset(&buf);
1989                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1990                                 die(_("Cannot autostash"));
1991                         strbuf_trim_trailing_newline(&buf);
1992                         if (get_oid(buf.buf, &oid))
1993                                 die(_("Unexpected stash response: '%s'"),
1994                                     buf.buf);
1995                         strbuf_reset(&buf);
1996                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1997
1998                         if (safe_create_leading_directories_const(autostash))
1999                                 die(_("Could not create directory for '%s'"),
2000                                     options.state_dir);
2001                         write_file(autostash, "%s", oid_to_hex(&oid));
2002                         printf(_("Created autostash: %s\n"), buf.buf);
2003                         if (reset_head(&head->object.oid, "reset --hard",
2004                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2005                                 die(_("could not reset --hard"));
2006                         printf(_("HEAD is now at %s"),
2007                                find_unique_abbrev(&head->object.oid,
2008                                                   DEFAULT_ABBREV));
2009                         strbuf_reset(&buf);
2010                         pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
2011                         if (buf.len > 0)
2012                                 printf(" %s", buf.buf);
2013                         putchar('\n');
2014
2015                         if (discard_index(the_repository->index) < 0 ||
2016                                 repo_read_index(the_repository) < 0)
2017                                 die(_("could not read index"));
2018                 }
2019         }
2020
2021         if (require_clean_work_tree(the_repository, "rebase",
2022                                     _("Please commit or stash them."), 1, 1)) {
2023                 ret = 1;
2024                 goto cleanup;
2025         }
2026
2027         /*
2028          * Now we are rebasing commits upstream..orig_head (or with --root,
2029          * everything leading up to orig_head) on top of onto.
2030          */
2031
2032         /*
2033          * Check if we are already based on onto with linear history,
2034          * but this should be done only when upstream and onto are the same
2035          * and if this is not an interactive rebase.
2036          */
2037         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
2038             !is_interactive(&options) && !options.restrict_revision &&
2039             options.upstream &&
2040             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
2041                 int flag;
2042
2043                 if (!(options.flags & REBASE_FORCE)) {
2044                         /* Lazily switch to the target branch if needed... */
2045                         if (options.switch_to) {
2046                                 struct object_id oid;
2047
2048                                 if (get_oid(options.switch_to, &oid) < 0) {
2049                                         ret = !!error(_("could not parse '%s'"),
2050                                                       options.switch_to);
2051                                         goto cleanup;
2052                                 }
2053
2054                                 strbuf_reset(&buf);
2055                                 strbuf_addf(&buf, "%s: checkout %s",
2056                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2057                                             options.switch_to);
2058                                 if (reset_head(&oid, "checkout",
2059                                                options.head_name,
2060                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2061                                                NULL, buf.buf) < 0) {
2062                                         ret = !!error(_("could not switch to "
2063                                                         "%s"),
2064                                                       options.switch_to);
2065                                         goto cleanup;
2066                                 }
2067                         }
2068
2069                         if (!(options.flags & REBASE_NO_QUIET))
2070                                 ; /* be quiet */
2071                         else if (!strcmp(branch_name, "HEAD") &&
2072                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2073                                 puts(_("HEAD is up to date."));
2074                         else
2075                                 printf(_("Current branch %s is up to date.\n"),
2076                                        branch_name);
2077                         ret = !!finish_rebase(&options);
2078                         goto cleanup;
2079                 } else if (!(options.flags & REBASE_NO_QUIET))
2080                         ; /* be quiet */
2081                 else if (!strcmp(branch_name, "HEAD") &&
2082                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2083                         puts(_("HEAD is up to date, rebase forced."));
2084                 else
2085                         printf(_("Current branch %s is up to date, rebase "
2086                                  "forced.\n"), branch_name);
2087         }
2088
2089         /* If a hook exists, give it a chance to interrupt*/
2090         if (!ok_to_skip_pre_rebase &&
2091             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2092                         argc ? argv[0] : NULL, NULL))
2093                 die(_("The pre-rebase hook refused to rebase."));
2094
2095         if (options.flags & REBASE_DIFFSTAT) {
2096                 struct diff_options opts;
2097
2098                 if (options.flags & REBASE_VERBOSE) {
2099                         if (is_null_oid(&merge_base))
2100                                 printf(_("Changes to %s:\n"),
2101                                        oid_to_hex(&options.onto->object.oid));
2102                         else
2103                                 printf(_("Changes from %s to %s:\n"),
2104                                        oid_to_hex(&merge_base),
2105                                        oid_to_hex(&options.onto->object.oid));
2106                 }
2107
2108                 /* We want color (if set), but no pager */
2109                 diff_setup(&opts);
2110                 opts.stat_width = -1; /* use full terminal width */
2111                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2112                 opts.output_format |=
2113                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2114                 opts.detect_rename = DIFF_DETECT_RENAME;
2115                 diff_setup_done(&opts);
2116                 diff_tree_oid(is_null_oid(&merge_base) ?
2117                               the_hash_algo->empty_tree : &merge_base,
2118                               &options.onto->object.oid, "", &opts);
2119                 diffcore_std(&opts);
2120                 diff_flush(&opts);
2121         }
2122
2123         if (is_interactive(&options))
2124                 goto run_rebase;
2125
2126         /* Detach HEAD and reset the tree */
2127         if (options.flags & REBASE_NO_QUIET)
2128                 printf(_("First, rewinding head to replay your work on top of "
2129                          "it...\n"));
2130
2131         strbuf_addf(&msg, "%s: checkout %s",
2132                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2133         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2134                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2135                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2136                        NULL, msg.buf))
2137                 die(_("Could not detach HEAD"));
2138         strbuf_release(&msg);
2139
2140         /*
2141          * If the onto is a proper descendant of the tip of the branch, then
2142          * we just fast-forwarded.
2143          */
2144         strbuf_reset(&msg);
2145         if (oideq(&merge_base, &options.orig_head)) {
2146                 printf(_("Fast-forwarded %s to %s.\n"),
2147                         branch_name, options.onto_name);
2148                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2149                         options.head_name ? options.head_name : "detached HEAD",
2150                         oid_to_hex(&options.onto->object.oid));
2151                 reset_head(NULL, "Fast-forwarded", options.head_name,
2152                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2153                 strbuf_release(&msg);
2154                 ret = !!finish_rebase(&options);
2155                 goto cleanup;
2156         }
2157
2158         strbuf_addf(&revisions, "%s..%s",
2159                     options.root ? oid_to_hex(&options.onto->object.oid) :
2160                     (options.restrict_revision ?
2161                      oid_to_hex(&options.restrict_revision->object.oid) :
2162                      oid_to_hex(&options.upstream->object.oid)),
2163                     oid_to_hex(&options.orig_head));
2164
2165         options.revisions = revisions.buf;
2166
2167 run_rebase:
2168         ret = !!run_specific_rebase(&options, action);
2169
2170 cleanup:
2171         strbuf_release(&buf);
2172         strbuf_release(&revisions);
2173         free(options.head_name);
2174         free(options.gpg_sign_opt);
2175         free(options.cmd);
2176         free(squash_onto_name);
2177         return ret;
2178 }