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

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   8 #include "builtin.h"
   9 #include "run-command.h"
  10 #include "exec-cmd.h"
  11 #include "argv-array.h"
  12 #include "dir.h"
  13 #include "packfile.h"
  14 #include "refs.h"
  15 #include "quote.h"
  16 #include "config.h"
  17 #include "cache-tree.h"
  18 #include "unpack-trees.h"
  19 #include "lockfile.h"
  20 #include "parse-options.h"
  21 #include "commit.h"
  22 #include "diff.h"
  23 #include "wt-status.h"
  24 #include "revision.h"
  25 #include "commit-reach.h"
  26 #include "rerere.h"
  27 #include "branch.h"
  28 #include "sequencer.h"
  29 #include "rebase-interactive.h"
  30
  31 static char const * const builtin_rebase_usage[] = {
  32         N_("git rebase [-i] [options] [--exec <cmd>] "
  33                 "[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
  34         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  35                 "--root [<branch>]"),
  36         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  37         NULL
  38 };
  39
  40 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
  41 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
  42 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  43 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  44
  45 enum rebase_type {
  46         REBASE_UNSPECIFIED = -1,
  47         REBASE_AM,
  48         REBASE_MERGE,
  49         REBASE_INTERACTIVE,
  50         REBASE_PRESERVE_MERGES
  51 };
  52
  53 struct rebase_options {
  54         enum rebase_type type;
  55         const char *state_dir;
  56         struct commit *upstream;
  57         const char *upstream_name;
  58         const char *upstream_arg;
  59         char *head_name;
  60         struct object_id orig_head;
  61         struct commit *onto;
  62         const char *onto_name;
  63         const char *revisions;
  64         const char *switch_to;
  65         int root, root_with_onto;
  66         struct object_id *squash_onto;
  67         struct commit *restrict_revision;
  68         int dont_finish_rebase;
  69         enum {
  70                 REBASE_NO_QUIET = 1<<0,
  71                 REBASE_VERBOSE = 1<<1,
  72                 REBASE_DIFFSTAT = 1<<2,
  73                 REBASE_FORCE = 1<<3,
  74                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  75         } flags;
  76         struct argv_array git_am_opts;
  77         const char *action;
  78         int signoff;
  79         int allow_rerere_autoupdate;
  80         int keep_empty;
  81         int autosquash;
  82         char *gpg_sign_opt;
  83         int autostash;
  84         char *cmd;
  85         int allow_empty_message;
  86         int rebase_merges, rebase_cousins;
  87         char *strategy, *strategy_opts;
  88         struct strbuf git_format_patch_opt;
  89         int reschedule_failed_exec;
  90         int use_legacy_rebase;
  91 };
  92
  93 #define REBASE_OPTIONS_INIT {                           \
  94                 .type = REBASE_UNSPECIFIED,             \
  95                 .flags = REBASE_NO_QUIET,               \
  96                 .git_am_opts = ARGV_ARRAY_INIT,         \
  97                 .git_format_patch_opt = STRBUF_INIT     \
  98         }
  99
 100 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 101 {
 102         struct replay_opts replay = REPLAY_OPTS_INIT;
 103
 104         replay.action = REPLAY_INTERACTIVE_REBASE;
 105         sequencer_init_config(&replay);
 106
 107         replay.signoff = opts->signoff;
 108         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 109         if (opts->allow_rerere_autoupdate)
 110                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 111         replay.allow_empty = 1;
 112         replay.allow_empty_message = opts->allow_empty_message;
 113         replay.verbose = opts->flags & REBASE_VERBOSE;
 114         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 115         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 116         replay.strategy = opts->strategy;
 117         if (opts->strategy_opts)
 118                 parse_strategy_opts(&replay, opts->strategy_opts);
 119
 120         if (opts->squash_onto) {
 121                 oidcpy(&replay.squash_onto, opts->squash_onto);
 122                 replay.have_squash_onto = 1;
 123         }
 124
 125         return replay;
 126 }
 127
 128 enum action {
 129         ACTION_NONE = 0,
 130         ACTION_CONTINUE,
 131         ACTION_SKIP,
 132         ACTION_ABORT,
 133         ACTION_QUIT,
 134         ACTION_EDIT_TODO,
 135         ACTION_SHOW_CURRENT_PATCH,
 136         ACTION_SHORTEN_OIDS,
 137         ACTION_EXPAND_OIDS,
 138         ACTION_CHECK_TODO_LIST,
 139         ACTION_REARRANGE_SQUASH,
 140         ACTION_ADD_EXEC
 141 };
 142
 143 static const char *action_names[] = { "undefined",
 144                                       "continue",
 145                                       "skip",
 146                                       "abort",
 147                                       "quit",
 148                                       "edit_todo",
 149                                       "show_current_patch" };
 150
 151 static int add_exec_commands(struct string_list *commands)
 152 {
 153         const char *todo_file = rebase_path_todo();
 154         struct todo_list todo_list = TODO_LIST_INIT;
 155         int res;
 156
 157         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 158                 return error_errno(_("could not read '%s'."), todo_file);
 159
 160         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 161                                         &todo_list)) {
 162                 todo_list_release(&todo_list);
 163                 return error(_("unusable todo list: '%s'"), todo_file);
 164         }
 165
 166         todo_list_add_exec_commands(&todo_list, commands);
 167         res = todo_list_write_to_file(the_repository, &todo_list,
 168                                       todo_file, NULL, NULL, -1, 0);
 169         todo_list_release(&todo_list);
 170
 171         if (res)
 172                 return error_errno(_("could not write '%s'."), todo_file);
 173         return 0;
 174 }
 175
 176 static int rearrange_squash_in_todo_file(void)
 177 {
 178         const char *todo_file = rebase_path_todo();
 179         struct todo_list todo_list = TODO_LIST_INIT;
 180         int res = 0;
 181
 182         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 183                 return error_errno(_("could not read '%s'."), todo_file);
 184         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 185                                         &todo_list)) {
 186                 todo_list_release(&todo_list);
 187                 return error(_("unusable todo list: '%s'"), todo_file);
 188         }
 189
 190         res = todo_list_rearrange_squash(&todo_list);
 191         if (!res)
 192                 res = todo_list_write_to_file(the_repository, &todo_list,
 193                                               todo_file, NULL, NULL, -1, 0);
 194
 195         todo_list_release(&todo_list);
 196
 197         if (res)
 198                 return error_errno(_("could not write '%s'."), todo_file);
 199         return 0;
 200 }
 201
 202 static int transform_todo_file(unsigned flags)
 203 {
 204         const char *todo_file = rebase_path_todo();
 205         struct todo_list todo_list = TODO_LIST_INIT;
 206         int res;
 207
 208         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 209                 return error_errno(_("could not read '%s'."), todo_file);
 210
 211         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 212                                         &todo_list)) {
 213                 todo_list_release(&todo_list);
 214                 return error(_("unusable todo list: '%s'"), todo_file);
 215         }
 216
 217         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 218                                       NULL, NULL, -1, flags);
 219         todo_list_release(&todo_list);
 220
 221         if (res)
 222                 return error_errno(_("could not write '%s'."), todo_file);
 223         return 0;
 224 }
 225
 226 static int edit_todo_file(unsigned flags)
 227 {
 228         const char *todo_file = rebase_path_todo();
 229         struct todo_list todo_list = TODO_LIST_INIT,
 230                 new_todo = TODO_LIST_INIT;
 231         int res = 0;
 232
 233         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 234                 return error_errno(_("could not read '%s'."), todo_file);
 235
 236         strbuf_stripspace(&todo_list.buf, 1);
 237         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 238         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 239                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 240                 res = error_errno(_("could not write '%s'"), todo_file);
 241
 242         todo_list_release(&todo_list);
 243         todo_list_release(&new_todo);
 244
 245         return res;
 246 }
 247
 248 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 249                                const char **head_hash,
 250                                char **revisions, char **shortrevisions)
 251 {
 252         struct commit *base_rev = upstream ? upstream : onto;
 253         const char *shorthead;
 254         struct object_id orig_head;
 255
 256         if (get_oid("HEAD", &orig_head))
 257                 return error(_("no HEAD?"));
 258
 259         *head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
 260         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 261                                                    *head_hash);
 262
 263         shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
 264
 265         if (upstream) {
 266                 const char *shortrev;
 267
 268                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 269                                               DEFAULT_ABBREV);
 270
 271                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 272         } else
 273                 *shortrevisions = xstrdup(shorthead);
 274
 275         return 0;
 276 }
 277
 278 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 279                             struct commit *onto, const char *orig_head)
 280 {
 281         FILE *interactive;
 282
 283         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 284                 return error_errno(_("could not create temporary %s"), merge_dir());
 285
 286         delete_reflog("REBASE_HEAD");
 287
 288         interactive = fopen(path_interactive(), "w");
 289         if (!interactive)
 290                 return error_errno(_("could not mark as interactive"));
 291         fclose(interactive);
 292
 293         return write_basic_state(opts, head_name, onto, orig_head);
 294 }
 295
 296 static void split_exec_commands(const char *cmd, struct string_list *commands)
 297 {
 298         if (cmd && *cmd) {
 299                 string_list_split(commands, cmd, '\n', -1);
 300
 301                 /* rebase.c adds a new line to cmd after every command,
 302                  * so here the last command is always empty */
 303                 string_list_remove_empty_items(commands, 0);
 304         }
 305 }
 306
 307 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 308 {
 309         int ret;
 310         const char *head_hash = NULL;
 311         char *revisions = NULL, *shortrevisions = NULL;
 312         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 313         struct todo_list todo_list = TODO_LIST_INIT;
 314         struct replay_opts replay = get_replay_opts(opts);
 315         struct string_list commands = STRING_LIST_INIT_DUP;
 316
 317         if (prepare_branch_to_be_rebased(the_repository, &replay,
 318                                          opts->switch_to))
 319                 return -1;
 320
 321         if (get_revision_ranges(opts->upstream, opts->onto, &head_hash,
 322                                 &revisions, &shortrevisions))
 323                 return -1;
 324
 325         if (init_basic_state(&replay,
 326                              opts->head_name ? opts->head_name : "detached HEAD",
 327                              opts->onto, head_hash)) {
 328                 free(revisions);
 329                 free(shortrevisions);
 330
 331                 return -1;
 332         }
 333
 334         if (!opts->upstream && opts->squash_onto)
 335                 write_file(path_squash_onto(), "%s\n",
 336                            oid_to_hex(opts->squash_onto));
 337
 338         argv_array_pushl(&make_script_args, "", revisions, NULL);
 339         if (opts->restrict_revision)
 340                 argv_array_push(&make_script_args,
 341                                 oid_to_hex(&opts->restrict_revision->object.oid));
 342
 343         ret = sequencer_make_script(the_repository, &todo_list.buf,
 344                                     make_script_args.argc, make_script_args.argv,
 345                                     flags);
 346
 347         if (ret)
 348                 error(_("could not generate todo list"));
 349         else {
 350                 discard_cache();
 351                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 352                                                 &todo_list))
 353                         BUG("unusable todo list");
 354
 355                 split_exec_commands(opts->cmd, &commands);
 356                 ret = complete_action(the_repository, &replay, flags,
 357                         shortrevisions, opts->onto_name, opts->onto, head_hash,
 358                         &commands, opts->autosquash, &todo_list);
 359         }
 360
 361         string_list_clear(&commands, 0);
 362         free(revisions);
 363         free(shortrevisions);
 364         todo_list_release(&todo_list);
 365         argv_array_clear(&make_script_args);
 366
 367         return ret;
 368 }
 369
 370 static int run_rebase_interactive(struct rebase_options *opts,
 371                                   enum action command)
 372 {
 373         unsigned flags = 0;
 374         int abbreviate_commands = 0, ret = 0;
 375
 376         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 377
 378         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 379         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 380         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 381         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 382         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 383         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 384
 385         switch (command) {
 386         case ACTION_NONE: {
 387                 if (!opts->onto && !opts->upstream)
 388                         die(_("a base commit must be provided with --upstream or --onto"));
 389
 390                 ret = do_interactive_rebase(opts, flags);
 391                 break;
 392         }
 393         case ACTION_SKIP: {
 394                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 395
 396                 rerere_clear(the_repository, &merge_rr);
 397         }
 398                 /* fallthrough */
 399         case ACTION_CONTINUE: {
 400                 struct replay_opts replay_opts = get_replay_opts(opts);
 401
 402                 ret = sequencer_continue(the_repository, &replay_opts);
 403                 break;
 404         }
 405         case ACTION_EDIT_TODO:
 406                 ret = edit_todo_file(flags);
 407                 break;
 408         case ACTION_SHOW_CURRENT_PATCH: {
 409                 struct child_process cmd = CHILD_PROCESS_INIT;
 410
 411                 cmd.git_cmd = 1;
 412                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 413                 ret = run_command(&cmd);
 414
 415                 break;
 416         }
 417         case ACTION_SHORTEN_OIDS:
 418         case ACTION_EXPAND_OIDS:
 419                 ret = transform_todo_file(flags);
 420                 break;
 421         case ACTION_CHECK_TODO_LIST:
 422                 ret = check_todo_list_from_file(the_repository);
 423                 break;
 424         case ACTION_REARRANGE_SQUASH:
 425                 ret = rearrange_squash_in_todo_file();
 426                 break;
 427         case ACTION_ADD_EXEC: {
 428                 struct string_list commands = STRING_LIST_INIT_DUP;
 429
 430                 split_exec_commands(opts->cmd, &commands);
 431                 ret = add_exec_commands(&commands);
 432                 string_list_clear(&commands, 0);
 433                 break;
 434         }
 435         default:
 436                 BUG("invalid command '%d'", command);
 437         }
 438
 439         return ret;
 440 }
 441
 442 static const char * const builtin_rebase_interactive_usage[] = {
 443         N_("git rebase--interactive [<options>]"),
 444         NULL
 445 };
 446
 447 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 448 {
 449         struct rebase_options opts = REBASE_OPTIONS_INIT;
 450         struct object_id squash_onto = null_oid;
 451         enum action command = ACTION_NONE;
 452         struct option options[] = {
 453                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 454                            REBASE_FORCE),
 455                 OPT_BOOL(0, "keep-empty", &opts.keep_empty, N_("keep empty commits")),
 456                 OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
 457                          N_("allow commits with empty messages")),
 458                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 459                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 460                          N_("keep original branch points of cousins")),
 461                 OPT_BOOL(0, "autosquash", &opts.autosquash,
 462                          N_("move commits that begin with squash!/fixup!")),
 463                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 464                 OPT_BIT('v', "verbose", &opts.flags,
 465                         N_("display a diffstat of what changed upstream"),
 466                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 467                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 468                             ACTION_CONTINUE),
 469                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 470                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 471                             ACTION_EDIT_TODO),
 472                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 473                             ACTION_SHOW_CURRENT_PATCH),
 474                 OPT_CMDMODE(0, "shorten-ids", &command,
 475                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 476                 OPT_CMDMODE(0, "expand-ids", &command,
 477                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 478                 OPT_CMDMODE(0, "check-todo-list", &command,
 479                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 480                 OPT_CMDMODE(0, "rearrange-squash", &command,
 481                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 482                 OPT_CMDMODE(0, "add-exec-commands", &command,
 483                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 484                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 485                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 486                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 487                   N_("restrict-revision"), N_("restrict revision"),
 488                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 489                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 490                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 491                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 492                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 493                   0 },
 494                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 495                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 496                         N_("GPG-sign commits"),
 497                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 498                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 499                            N_("rebase strategy")),
 500                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 501                            N_("strategy options")),
 502                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 503                            N_("the branch or commit to checkout")),
 504                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 505                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 506                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 507                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 508                          N_("automatically re-schedule any `exec` that fails")),
 509                 OPT_END()
 510         };
 511
 512         opts.rebase_cousins = -1;
 513
 514         if (argc == 1)
 515                 usage_with_options(builtin_rebase_interactive_usage, options);
 516
 517         argc = parse_options(argc, argv, prefix, options,
 518                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 519
 520         if (!is_null_oid(&squash_onto))
 521                 opts.squash_onto = &squash_onto;
 522
 523         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 524                 warning(_("--[no-]rebase-cousins has no effect without "
 525                           "--rebase-merges"));
 526
 527         return !!run_rebase_interactive(&opts, command);
 528 }
 529
 530 static int is_interactive(struct rebase_options *opts)
 531 {
 532         return opts->type == REBASE_INTERACTIVE ||
 533                 opts->type == REBASE_PRESERVE_MERGES;
 534 }
 535
 536 static void imply_interactive(struct rebase_options *opts, const char *option)
 537 {
 538         switch (opts->type) {
 539         case REBASE_AM:
 540                 die(_("%s requires an interactive rebase"), option);
 541                 break;
 542         case REBASE_INTERACTIVE:
 543         case REBASE_PRESERVE_MERGES:
 544                 break;
 545         case REBASE_MERGE:
 546                 /* we now implement --merge via --interactive */
 547         default:
 548                 opts->type = REBASE_INTERACTIVE; /* implied */
 549                 break;
 550         }
 551 }
 552
 553 /* Returns the filename prefixed by the state_dir */
 554 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 555 {
 556         static struct strbuf path = STRBUF_INIT;
 557         static size_t prefix_len;
 558
 559         if (!prefix_len) {
 560                 strbuf_addf(&path, "%s/", opts->state_dir);
 561                 prefix_len = path.len;
 562         }
 563
 564         strbuf_setlen(&path, prefix_len);
 565         strbuf_addstr(&path, filename);
 566         return path.buf;
 567 }
 568
 569 /* Read one file, then strip line endings */
 570 static int read_one(const char *path, struct strbuf *buf)
 571 {
 572         if (strbuf_read_file(buf, path, 0) < 0)
 573                 return error_errno(_("could not read '%s'"), path);
 574         strbuf_trim_trailing_newline(buf);
 575         return 0;
 576 }
 577
 578 /* Initialize the rebase options from the state directory. */
 579 static int read_basic_state(struct rebase_options *opts)
 580 {
 581         struct strbuf head_name = STRBUF_INIT;
 582         struct strbuf buf = STRBUF_INIT;
 583         struct object_id oid;
 584
 585         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 586             read_one(state_dir_path("onto", opts), &buf))
 587                 return -1;
 588         opts->head_name = starts_with(head_name.buf, "refs/") ?
 589                 xstrdup(head_name.buf) : NULL;
 590         strbuf_release(&head_name);
 591         if (get_oid(buf.buf, &oid))
 592                 return error(_("could not get 'onto': '%s'"), buf.buf);
 593         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 594
 595         /*
 596          * We always write to orig-head, but interactive rebase used to write to
 597          * head. Fall back to reading from head to cover for the case that the
 598          * user upgraded git with an ongoing interactive rebase.
 599          */
 600         strbuf_reset(&buf);
 601         if (file_exists(state_dir_path("orig-head", opts))) {
 602                 if (read_one(state_dir_path("orig-head", opts), &buf))
 603                         return -1;
 604         } else if (read_one(state_dir_path("head", opts), &buf))
 605                 return -1;
 606         if (get_oid(buf.buf, &opts->orig_head))
 607                 return error(_("invalid orig-head: '%s'"), buf.buf);
 608
 609         if (file_exists(state_dir_path("quiet", opts)))
 610                 opts->flags &= ~REBASE_NO_QUIET;
 611         else
 612                 opts->flags |= REBASE_NO_QUIET;
 613
 614         if (file_exists(state_dir_path("verbose", opts)))
 615                 opts->flags |= REBASE_VERBOSE;
 616
 617         if (file_exists(state_dir_path("signoff", opts))) {
 618                 opts->signoff = 1;
 619                 opts->flags |= REBASE_FORCE;
 620         }
 621
 622         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 623                 strbuf_reset(&buf);
 624                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 625                             &buf))
 626                         return -1;
 627                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 628                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 629                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 630                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 631                 else
 632                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 633                                   "'%s'"), buf.buf);
 634         }
 635
 636         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 637                 strbuf_reset(&buf);
 638                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 639                             &buf))
 640                         return -1;
 641                 free(opts->gpg_sign_opt);
 642                 opts->gpg_sign_opt = xstrdup(buf.buf);
 643         }
 644
 645         if (file_exists(state_dir_path("strategy", opts))) {
 646                 strbuf_reset(&buf);
 647                 if (read_one(state_dir_path("strategy", opts), &buf))
 648                         return -1;
 649                 free(opts->strategy);
 650                 opts->strategy = xstrdup(buf.buf);
 651         }
 652
 653         if (file_exists(state_dir_path("strategy_opts", opts))) {
 654                 strbuf_reset(&buf);
 655                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 656                         return -1;
 657                 free(opts->strategy_opts);
 658                 opts->strategy_opts = xstrdup(buf.buf);
 659         }
 660
 661         strbuf_release(&buf);
 662
 663         return 0;
 664 }
 665
 666 static int rebase_write_basic_state(struct rebase_options *opts)
 667 {
 668         write_file(state_dir_path("head-name", opts), "%s",
 669                    opts->head_name ? opts->head_name : "detached HEAD");
 670         write_file(state_dir_path("onto", opts), "%s",
 671                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 672         write_file(state_dir_path("orig-head", opts), "%s",
 673                    oid_to_hex(&opts->orig_head));
 674         write_file(state_dir_path("quiet", opts), "%s",
 675                    opts->flags & REBASE_NO_QUIET ? "" : "t");
 676         if (opts->flags & REBASE_VERBOSE)
 677                 write_file(state_dir_path("verbose", opts), "%s", "");
 678         if (opts->strategy)
 679                 write_file(state_dir_path("strategy", opts), "%s",
 680                            opts->strategy);
 681         if (opts->strategy_opts)
 682                 write_file(state_dir_path("strategy_opts", opts), "%s",
 683                            opts->strategy_opts);
 684         if (opts->allow_rerere_autoupdate > 0)
 685                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 686                            "-%s-rerere-autoupdate",
 687                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 688                                 "" : "-no");
 689         if (opts->gpg_sign_opt)
 690                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 691                            opts->gpg_sign_opt);
 692         if (opts->signoff)
 693                 write_file(state_dir_path("signoff", opts), "--signoff");
 694
 695         return 0;
 696 }
 697
 698 static int apply_autostash(struct rebase_options *opts)
 699 {
 700         const char *path = state_dir_path("autostash", opts);
 701         struct strbuf autostash = STRBUF_INIT;
 702         struct child_process stash_apply = CHILD_PROCESS_INIT;
 703
 704         if (!file_exists(path))
 705                 return 0;
 706
 707         if (read_one(path, &autostash))
 708                 return error(_("Could not read '%s'"), path);
 709         /* Ensure that the hash is not mistaken for a number */
 710         strbuf_addstr(&autostash, "^0");
 711         argv_array_pushl(&stash_apply.args,
 712                          "stash", "apply", autostash.buf, NULL);
 713         stash_apply.git_cmd = 1;
 714         stash_apply.no_stderr = stash_apply.no_stdout =
 715                 stash_apply.no_stdin = 1;
 716         if (!run_command(&stash_apply))
 717                 printf(_("Applied autostash.\n"));
 718         else {
 719                 struct argv_array args = ARGV_ARRAY_INIT;
 720                 int res = 0;
 721
 722                 argv_array_pushl(&args,
 723                                  "stash", "store", "-m", "autostash", "-q",
 724                                  autostash.buf, NULL);
 725                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 726                         res = error(_("Cannot store %s"), autostash.buf);
 727                 argv_array_clear(&args);
 728                 strbuf_release(&autostash);
 729                 if (res)
 730                         return res;
 731
 732                 fprintf(stderr,
 733                         _("Applying autostash resulted in conflicts.\n"
 734                           "Your changes are safe in the stash.\n"
 735                           "You can run \"git stash pop\" or \"git stash drop\" "
 736                           "at any time.\n"));
 737         }
 738
 739         strbuf_release(&autostash);
 740         return 0;
 741 }
 742
 743 static int finish_rebase(struct rebase_options *opts)
 744 {
 745         struct strbuf dir = STRBUF_INIT;
 746         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 747         int ret = 0;
 748
 749         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 750         apply_autostash(opts);
 751         close_object_store(the_repository->objects);
 752         /*
 753          * We ignore errors in 'gc --auto', since the
 754          * user should see them.
 755          */
 756         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 757         if (opts->type == REBASE_INTERACTIVE) {
 758                 struct replay_opts replay = REPLAY_OPTS_INIT;
 759
 760                 replay.action = REPLAY_INTERACTIVE_REBASE;
 761                 ret = sequencer_remove_state(&replay);
 762         } else {
 763                 strbuf_addstr(&dir, opts->state_dir);
 764                 if (remove_dir_recursively(&dir, 0))
 765                         ret = error(_("could not remove '%s'"),
 766                                     opts->state_dir);
 767                 strbuf_release(&dir);
 768         }
 769
 770         return ret;
 771 }
 772
 773 static struct commit *peel_committish(const char *name)
 774 {
 775         struct object *obj;
 776         struct object_id oid;
 777
 778         if (get_oid(name, &oid))
 779                 return NULL;
 780         obj = parse_object(the_repository, &oid);
 781         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 782 }
 783
 784 static void add_var(struct strbuf *buf, const char *name, const char *value)
 785 {
 786         if (!value)
 787                 strbuf_addf(buf, "unset %s; ", name);
 788         else {
 789                 strbuf_addf(buf, "%s=", name);
 790                 sq_quote_buf(buf, value);
 791                 strbuf_addstr(buf, "; ");
 792         }
 793 }
 794
 795 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 796
 797 #define RESET_HEAD_DETACH (1<<0)
 798 #define RESET_HEAD_HARD (1<<1)
 799 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 800 #define RESET_HEAD_REFS_ONLY (1<<3)
 801 #define RESET_ORIG_HEAD (1<<4)
 802
 803 static int reset_head(struct object_id *oid, const char *action,
 804                       const char *switch_to_branch, unsigned flags,
 805                       const char *reflog_orig_head, const char *reflog_head)
 806 {
 807         unsigned detach_head = flags & RESET_HEAD_DETACH;
 808         unsigned reset_hard = flags & RESET_HEAD_HARD;
 809         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 810         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 811         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 812         struct object_id head_oid;
 813         struct tree_desc desc[2] = { { NULL }, { NULL } };
 814         struct lock_file lock = LOCK_INIT;
 815         struct unpack_trees_options unpack_tree_opts;
 816         struct tree *tree;
 817         const char *reflog_action;
 818         struct strbuf msg = STRBUF_INIT;
 819         size_t prefix_len;
 820         struct object_id *orig = NULL, oid_orig,
 821                 *old_orig = NULL, oid_old_orig;
 822         int ret = 0, nr = 0;
 823
 824         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 825                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 826
 827         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 828                 ret = -1;
 829                 goto leave_reset_head;
 830         }
 831
 832         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 833                 ret = error(_("could not determine HEAD revision"));
 834                 goto leave_reset_head;
 835         }
 836
 837         if (!oid)
 838                 oid = &head_oid;
 839
 840         if (refs_only)
 841                 goto reset_head_refs;
 842
 843         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 844         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 845         unpack_tree_opts.head_idx = 1;
 846         unpack_tree_opts.src_index = the_repository->index;
 847         unpack_tree_opts.dst_index = the_repository->index;
 848         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 849         unpack_tree_opts.update = 1;
 850         unpack_tree_opts.merge = 1;
 851         if (!detach_head)
 852                 unpack_tree_opts.reset = 1;
 853
 854         if (repo_read_index_unmerged(the_repository) < 0) {
 855                 ret = error(_("could not read index"));
 856                 goto leave_reset_head;
 857         }
 858
 859         if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 860                 ret = error(_("failed to find tree of %s"),
 861                             oid_to_hex(&head_oid));
 862                 goto leave_reset_head;
 863         }
 864
 865         if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 866                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 867                 goto leave_reset_head;
 868         }
 869
 870         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 871                 ret = -1;
 872                 goto leave_reset_head;
 873         }
 874
 875         tree = parse_tree_indirect(oid);
 876         prime_cache_tree(the_repository, the_repository->index, tree);
 877
 878         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 879                 ret = error(_("could not write index"));
 880                 goto leave_reset_head;
 881         }
 882
 883 reset_head_refs:
 884         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 885         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 886         prefix_len = msg.len;
 887
 888         if (update_orig_head) {
 889                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 890                         old_orig = &oid_old_orig;
 891                 if (!get_oid("HEAD", &oid_orig)) {
 892                         orig = &oid_orig;
 893                         if (!reflog_orig_head) {
 894                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 895                                 reflog_orig_head = msg.buf;
 896                         }
 897                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 898                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 899                 } else if (old_orig)
 900                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 901         }
 902
 903         if (!reflog_head) {
 904                 strbuf_setlen(&msg, prefix_len);
 905                 strbuf_addstr(&msg, "updating HEAD");
 906                 reflog_head = msg.buf;
 907         }
 908         if (!switch_to_branch)
 909                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 910                                  detach_head ? REF_NO_DEREF : 0,
 911                                  UPDATE_REFS_MSG_ON_ERR);
 912         else {
 913                 ret = update_ref(reflog_head, switch_to_branch, oid,
 914                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 915                 if (!ret)
 916                         ret = create_symref("HEAD", switch_to_branch,
 917                                             reflog_head);
 918         }
 919         if (run_hook)
 920                 run_hook_le(NULL, "post-checkout",
 921                             oid_to_hex(orig ? orig : &null_oid),
 922                             oid_to_hex(oid), "1", NULL);
 923
 924 leave_reset_head:
 925         strbuf_release(&msg);
 926         rollback_lock_file(&lock);
 927         while (nr)
 928                 free((void *)desc[--nr].buffer);
 929         return ret;
 930 }
 931
 932 static int move_to_original_branch(struct rebase_options *opts)
 933 {
 934         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 935         int ret;
 936
 937         if (!opts->head_name)
 938                 return 0; /* nothing to move back to */
 939
 940         if (!opts->onto)
 941                 BUG("move_to_original_branch without onto");
 942
 943         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 944                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 945         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 946                     opts->head_name);
 947         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 948                          orig_head_reflog.buf, head_reflog.buf);
 949
 950         strbuf_release(&orig_head_reflog);
 951         strbuf_release(&head_reflog);
 952         return ret;
 953 }
 954
 955 static const char *resolvemsg =
 956 N_("Resolve all conflicts manually, mark them as resolved with\n"
 957 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 958 "You can instead skip this commit: run \"git rebase --skip\".\n"
 959 "To abort and get back to the state before \"git rebase\", run "
 960 "\"git rebase --abort\".");
 961
 962 static int run_am(struct rebase_options *opts)
 963 {
 964         struct child_process am = CHILD_PROCESS_INIT;
 965         struct child_process format_patch = CHILD_PROCESS_INIT;
 966         struct strbuf revisions = STRBUF_INIT;
 967         int status;
 968         char *rebased_patches;
 969
 970         am.git_cmd = 1;
 971         argv_array_push(&am.args, "am");
 972
 973         if (opts->action && !strcmp("continue", opts->action)) {
 974                 argv_array_push(&am.args, "--resolved");
 975                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 976                 if (opts->gpg_sign_opt)
 977                         argv_array_push(&am.args, opts->gpg_sign_opt);
 978                 status = run_command(&am);
 979                 if (status)
 980                         return status;
 981
 982                 return move_to_original_branch(opts);
 983         }
 984         if (opts->action && !strcmp("skip", opts->action)) {
 985                 argv_array_push(&am.args, "--skip");
 986                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 987                 status = run_command(&am);
 988                 if (status)
 989                         return status;
 990
 991                 return move_to_original_branch(opts);
 992         }
 993         if (opts->action && !strcmp("show-current-patch", opts->action)) {
 994                 argv_array_push(&am.args, "--show-current-patch");
 995                 return run_command(&am);
 996         }
 997
 998         strbuf_addf(&revisions, "%s...%s",
 999                     oid_to_hex(opts->root ?
1000                                /* this is now equivalent to !opts->upstream */
1001                                &opts->onto->object.oid :
1002                                &opts->upstream->object.oid),
1003                     oid_to_hex(&opts->orig_head));
1004
1005         rebased_patches = xstrdup(git_path("rebased-patches"));
1006         format_patch.out = open(rebased_patches,
1007                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1008         if (format_patch.out < 0) {
1009                 status = error_errno(_("could not open '%s' for writing"),
1010                                      rebased_patches);
1011                 free(rebased_patches);
1012                 argv_array_clear(&am.args);
1013                 return status;
1014         }
1015
1016         format_patch.git_cmd = 1;
1017         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1018                          "--full-index", "--cherry-pick", "--right-only",
1019                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1020                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
1021                          "--no-base", NULL);
1022         if (opts->git_format_patch_opt.len)
1023                 argv_array_split(&format_patch.args,
1024                                  opts->git_format_patch_opt.buf);
1025         argv_array_push(&format_patch.args, revisions.buf);
1026         if (opts->restrict_revision)
1027                 argv_array_pushf(&format_patch.args, "^%s",
1028                                  oid_to_hex(&opts->restrict_revision->object.oid));
1029
1030         status = run_command(&format_patch);
1031         if (status) {
1032                 unlink(rebased_patches);
1033                 free(rebased_patches);
1034                 argv_array_clear(&am.args);
1035
1036                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1037                            "HEAD", NULL);
1038                 error(_("\ngit encountered an error while preparing the "
1039                         "patches to replay\n"
1040                         "these revisions:\n"
1041                         "\n    %s\n\n"
1042                         "As a result, git cannot rebase them."),
1043                       opts->revisions);
1044
1045                 strbuf_release(&revisions);
1046                 return status;
1047         }
1048         strbuf_release(&revisions);
1049
1050         am.in = open(rebased_patches, O_RDONLY);
1051         if (am.in < 0) {
1052                 status = error_errno(_("could not open '%s' for reading"),
1053                                      rebased_patches);
1054                 free(rebased_patches);
1055                 argv_array_clear(&am.args);
1056                 return status;
1057         }
1058
1059         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1060         argv_array_push(&am.args, "--rebasing");
1061         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1062         argv_array_push(&am.args, "--patch-format=mboxrd");
1063         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1064                 argv_array_push(&am.args, "--rerere-autoupdate");
1065         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1066                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1067         if (opts->gpg_sign_opt)
1068                 argv_array_push(&am.args, opts->gpg_sign_opt);
1069         status = run_command(&am);
1070         unlink(rebased_patches);
1071         free(rebased_patches);
1072
1073         if (!status) {
1074                 return move_to_original_branch(opts);
1075         }
1076
1077         if (is_directory(opts->state_dir))
1078                 rebase_write_basic_state(opts);
1079
1080         return status;
1081 }
1082
1083 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1084 {
1085         const char *argv[] = { NULL, NULL };
1086         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1087         int status;
1088         const char *backend, *backend_func;
1089
1090         if (opts->type == REBASE_INTERACTIVE) {
1091                 /* Run builtin interactive rebase */
1092                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1093                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1094                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1095                         opts->autosquash = 0;
1096                 }
1097                 if (opts->gpg_sign_opt) {
1098                         /* remove the leading "-S" */
1099                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1100                         free(opts->gpg_sign_opt);
1101                         opts->gpg_sign_opt = tmp;
1102                 }
1103
1104                 status = run_rebase_interactive(opts, action);
1105                 goto finished_rebase;
1106         }
1107
1108         if (opts->type == REBASE_AM) {
1109                 status = run_am(opts);
1110                 goto finished_rebase;
1111         }
1112
1113         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1114         add_var(&script_snippet, "state_dir", opts->state_dir);
1115
1116         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1117         add_var(&script_snippet, "upstream", opts->upstream ?
1118                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1119         add_var(&script_snippet, "head_name",
1120                 opts->head_name ? opts->head_name : "detached HEAD");
1121         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1122         add_var(&script_snippet, "onto", opts->onto ?
1123                 oid_to_hex(&opts->onto->object.oid) : NULL);
1124         add_var(&script_snippet, "onto_name", opts->onto_name);
1125         add_var(&script_snippet, "revisions", opts->revisions);
1126         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1127                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1128         add_var(&script_snippet, "GIT_QUIET",
1129                 opts->flags & REBASE_NO_QUIET ? "" : "t");
1130         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1131         add_var(&script_snippet, "git_am_opt", buf.buf);
1132         strbuf_release(&buf);
1133         add_var(&script_snippet, "verbose",
1134                 opts->flags & REBASE_VERBOSE ? "t" : "");
1135         add_var(&script_snippet, "diffstat",
1136                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1137         add_var(&script_snippet, "force_rebase",
1138                 opts->flags & REBASE_FORCE ? "t" : "");
1139         if (opts->switch_to)
1140                 add_var(&script_snippet, "switch_to", opts->switch_to);
1141         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1142         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1143         add_var(&script_snippet, "allow_rerere_autoupdate",
1144                 opts->allow_rerere_autoupdate ?
1145                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1146                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1147         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1148         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1149         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1150         add_var(&script_snippet, "cmd", opts->cmd);
1151         add_var(&script_snippet, "allow_empty_message",
1152                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1153         add_var(&script_snippet, "rebase_merges",
1154                 opts->rebase_merges ? "t" : "");
1155         add_var(&script_snippet, "rebase_cousins",
1156                 opts->rebase_cousins ? "t" : "");
1157         add_var(&script_snippet, "strategy", opts->strategy);
1158         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1159         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1160         add_var(&script_snippet, "squash_onto",
1161                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1162         add_var(&script_snippet, "git_format_patch_opt",
1163                 opts->git_format_patch_opt.buf);
1164
1165         if (is_interactive(opts) &&
1166             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1167                 strbuf_addstr(&script_snippet,
1168                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1169                 opts->autosquash = 0;
1170         }
1171
1172         switch (opts->type) {
1173         case REBASE_PRESERVE_MERGES:
1174                 backend = "git-rebase--preserve-merges";
1175                 backend_func = "git_rebase__preserve_merges";
1176                 break;
1177         default:
1178                 BUG("Unhandled rebase type %d", opts->type);
1179                 break;
1180         }
1181
1182         strbuf_addf(&script_snippet,
1183                     ". git-sh-setup && . %s && %s", backend, backend_func);
1184         argv[0] = script_snippet.buf;
1185
1186         status = run_command_v_opt(argv, RUN_USING_SHELL);
1187 finished_rebase:
1188         if (opts->dont_finish_rebase)
1189                 ; /* do nothing */
1190         else if (opts->type == REBASE_INTERACTIVE)
1191                 ; /* interactive rebase cleans up after itself */
1192         else if (status == 0) {
1193                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1194                         finish_rebase(opts);
1195         } else if (status == 2) {
1196                 struct strbuf dir = STRBUF_INIT;
1197
1198                 apply_autostash(opts);
1199                 strbuf_addstr(&dir, opts->state_dir);
1200                 remove_dir_recursively(&dir, 0);
1201                 strbuf_release(&dir);
1202                 die("Nothing to do");
1203         }
1204
1205         strbuf_release(&script_snippet);
1206
1207         return status ? -1 : 0;
1208 }
1209
1210 static int rebase_config(const char *var, const char *value, void *data)
1211 {
1212         struct rebase_options *opts = data;
1213
1214         if (!strcmp(var, "rebase.stat")) {
1215                 if (git_config_bool(var, value))
1216                         opts->flags |= REBASE_DIFFSTAT;
1217                 else
1218                         opts->flags &= ~REBASE_DIFFSTAT;
1219                 return 0;
1220         }
1221
1222         if (!strcmp(var, "rebase.autosquash")) {
1223                 opts->autosquash = git_config_bool(var, value);
1224                 return 0;
1225         }
1226
1227         if (!strcmp(var, "commit.gpgsign")) {
1228                 free(opts->gpg_sign_opt);
1229                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1230                         xstrdup("-S") : NULL;
1231                 return 0;
1232         }
1233
1234         if (!strcmp(var, "rebase.autostash")) {
1235                 opts->autostash = git_config_bool(var, value);
1236                 return 0;
1237         }
1238
1239         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1240                 opts->reschedule_failed_exec = git_config_bool(var, value);
1241                 return 0;
1242         }
1243
1244         if (!strcmp(var, "rebase.usebuiltin")) {
1245                 opts->use_legacy_rebase = !git_config_bool(var, value);
1246                 return 0;
1247         }
1248
1249         return git_default_config(var, value, data);
1250 }
1251
1252 /*
1253  * Determines whether the commits in from..to are linear, i.e. contain
1254  * no merge commits. This function *expects* `from` to be an ancestor of
1255  * `to`.
1256  */
1257 static int is_linear_history(struct commit *from, struct commit *to)
1258 {
1259         while (to && to != from) {
1260                 parse_commit(to);
1261                 if (!to->parents)
1262                         return 1;
1263                 if (to->parents->next)
1264                         return 0;
1265                 to = to->parents->item;
1266         }
1267         return 1;
1268 }
1269
1270 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1271                             struct commit *restrict_revision,
1272                             struct object_id *head_oid, struct object_id *merge_base)
1273 {
1274         struct commit *head = lookup_commit(the_repository, head_oid);
1275         struct commit_list *merge_bases = NULL;
1276         int res = 0;
1277
1278         if (!head)
1279                 goto done;
1280
1281         merge_bases = get_merge_bases(onto, head);
1282         if (!merge_bases || merge_bases->next) {
1283                 oidcpy(merge_base, &null_oid);
1284                 goto done;
1285         }
1286
1287         oidcpy(merge_base, &merge_bases->item->object.oid);
1288         if (!oideq(merge_base, &onto->object.oid))
1289                 goto done;
1290
1291         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1292                 goto done;
1293
1294         if (!upstream)
1295                 goto done;
1296
1297         free_commit_list(merge_bases);
1298         merge_bases = get_merge_bases(upstream, head);
1299         if (!merge_bases || merge_bases->next)
1300                 goto done;
1301
1302         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1303                 goto done;
1304
1305         res = 1;
1306
1307 done:
1308         free_commit_list(merge_bases);
1309         return res && is_linear_history(onto, head);
1310 }
1311
1312 /* -i followed by -m is still -i */
1313 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1314 {
1315         struct rebase_options *opts = opt->value;
1316
1317         BUG_ON_OPT_NEG(unset);
1318         BUG_ON_OPT_ARG(arg);
1319
1320         if (!is_interactive(opts))
1321                 opts->type = REBASE_MERGE;
1322
1323         return 0;
1324 }
1325
1326 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1327 static int parse_opt_interactive(const struct option *opt, const char *arg,
1328                                  int unset)
1329 {
1330         struct rebase_options *opts = opt->value;
1331
1332         BUG_ON_OPT_NEG(unset);
1333         BUG_ON_OPT_ARG(arg);
1334
1335         opts->type = REBASE_INTERACTIVE;
1336         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1337
1338         return 0;
1339 }
1340
1341 static void NORETURN error_on_missing_default_upstream(void)
1342 {
1343         struct branch *current_branch = branch_get(NULL);
1344
1345         printf(_("%s\n"
1346                  "Please specify which branch you want to rebase against.\n"
1347                  "See git-rebase(1) for details.\n"
1348                  "\n"
1349                  "    git rebase '<branch>'\n"
1350                  "\n"),
1351                 current_branch ? _("There is no tracking information for "
1352                         "the current branch.") :
1353                         _("You are not currently on a branch."));
1354
1355         if (current_branch) {
1356                 const char *remote = current_branch->remote_name;
1357
1358                 if (!remote)
1359                         remote = _("<remote>");
1360
1361                 printf(_("If you wish to set tracking information for this "
1362                          "branch you can do so with:\n"
1363                          "\n"
1364                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1365                          "\n"),
1366                        remote, current_branch->name);
1367         }
1368         exit(1);
1369 }
1370
1371 static void set_reflog_action(struct rebase_options *options)
1372 {
1373         const char *env;
1374         struct strbuf buf = STRBUF_INIT;
1375
1376         if (!is_interactive(options))
1377                 return;
1378
1379         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1380         if (env && strcmp("rebase", env))
1381                 return; /* only override it if it is "rebase" */
1382
1383         strbuf_addf(&buf, "rebase -i (%s)", options->action);
1384         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1385         strbuf_release(&buf);
1386 }
1387
1388 static int check_exec_cmd(const char *cmd)
1389 {
1390         if (strchr(cmd, '\n'))
1391                 return error(_("exec commands cannot contain newlines"));
1392
1393         /* Does the command consist purely of whitespace? */
1394         if (!cmd[strspn(cmd, " \t\r\f\v")])
1395                 return error(_("empty exec command"));
1396
1397         return 0;
1398 }
1399
1400
1401 int cmd_rebase(int argc, const char **argv, const char *prefix)
1402 {
1403         struct rebase_options options = REBASE_OPTIONS_INIT;
1404         const char *branch_name;
1405         int ret, flags, total_argc, in_progress = 0;
1406         int keep_base = 0;
1407         int ok_to_skip_pre_rebase = 0;
1408         struct strbuf msg = STRBUF_INIT;
1409         struct strbuf revisions = STRBUF_INIT;
1410         struct strbuf buf = STRBUF_INIT;
1411         struct object_id merge_base;
1412         enum action action = ACTION_NONE;
1413         const char *gpg_sign = NULL;
1414         struct string_list exec = STRING_LIST_INIT_NODUP;
1415         const char *rebase_merges = NULL;
1416         int fork_point = -1;
1417         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1418         struct object_id squash_onto;
1419         char *squash_onto_name = NULL;
1420         int reschedule_failed_exec = -1;
1421         struct option builtin_rebase_options[] = {
1422                 OPT_STRING(0, "onto", &options.onto_name,
1423                            N_("revision"),
1424                            N_("rebase onto given branch instead of upstream")),
1425                 OPT_BOOL(0, "keep-base", &keep_base,
1426                          N_("use the merge-base of upstream and branch as the current base")),
1427                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1428                          N_("allow pre-rebase hook to run")),
1429                 OPT_NEGBIT('q', "quiet", &options.flags,
1430                            N_("be quiet. implies --no-stat"),
1431                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1432                 OPT_BIT('v', "verbose", &options.flags,
1433                         N_("display a diffstat of what changed upstream"),
1434                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1435                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1436                         N_("do not show diffstat of what changed upstream"),
1437                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1438                 OPT_BOOL(0, "signoff", &options.signoff,
1439                          N_("add a Signed-off-by: line to each commit")),
1440                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1441                                   NULL, N_("passed to 'git am'"),
1442                                   PARSE_OPT_NOARG),
1443                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1444                                   &options.git_am_opts, NULL,
1445                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1446                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1447                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1448                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1449                                   N_("passed to 'git apply'"), 0),
1450                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1451                                   N_("action"), N_("passed to 'git apply'"), 0),
1452                 OPT_BIT('f', "force-rebase", &options.flags,
1453                         N_("cherry-pick all commits, even if unchanged"),
1454                         REBASE_FORCE),
1455                 OPT_BIT(0, "no-ff", &options.flags,
1456                         N_("cherry-pick all commits, even if unchanged"),
1457                         REBASE_FORCE),
1458                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1459                             ACTION_CONTINUE),
1460                 OPT_CMDMODE(0, "skip", &action,
1461                             N_("skip current patch and continue"), ACTION_SKIP),
1462                 OPT_CMDMODE(0, "abort", &action,
1463                             N_("abort and check out the original branch"),
1464                             ACTION_ABORT),
1465                 OPT_CMDMODE(0, "quit", &action,
1466                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1467                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1468                             "during an interactive rebase"), ACTION_EDIT_TODO),
1469                 OPT_CMDMODE(0, "show-current-patch", &action,
1470                             N_("show the patch file being applied or merged"),
1471                             ACTION_SHOW_CURRENT_PATCH),
1472                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1473                         N_("use merging strategies to rebase"),
1474                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1475                         parse_opt_merge },
1476                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1477                         N_("let the user edit the list of commits to rebase"),
1478                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1479                         parse_opt_interactive },
1480                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1481                               N_("(DEPRECATED) try to recreate merges instead of "
1482                                  "ignoring them"),
1483                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1484                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1485                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
1486                          N_("preserve empty commits during rebase")),
1487                 OPT_BOOL(0, "autosquash", &options.autosquash,
1488                          N_("move commits that begin with "
1489                             "squash!/fixup! under -i")),
1490                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1491                         N_("GPG-sign commits"),
1492                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1493                 OPT_BOOL(0, "autostash", &options.autostash,
1494                          N_("automatically stash/stash pop before and after")),
1495                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1496                                 N_("add exec lines after each commit of the "
1497                                    "editable list")),
1498                 OPT_BOOL(0, "allow-empty-message",
1499                          &options.allow_empty_message,
1500                          N_("allow rebasing commits with empty messages")),
1501                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1502                         N_("mode"),
1503                         N_("try to rebase merges instead of skipping them"),
1504                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1505                 OPT_BOOL(0, "fork-point", &fork_point,
1506                          N_("use 'merge-base --fork-point' to refine upstream")),
1507                 OPT_STRING('s', "strategy", &options.strategy,
1508                            N_("strategy"), N_("use the given merge strategy")),
1509                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1510                                 N_("option"),
1511                                 N_("pass the argument through to the merge "
1512                                    "strategy")),
1513                 OPT_BOOL(0, "root", &options.root,
1514                          N_("rebase all reachable commits up to the root(s)")),
1515                 OPT_BOOL(0, "reschedule-failed-exec",
1516                          &reschedule_failed_exec,
1517                          N_("automatically re-schedule any `exec` that fails")),
1518                 OPT_END(),
1519         };
1520         int i;
1521
1522         if (argc == 2 && !strcmp(argv[1], "-h"))
1523                 usage_with_options(builtin_rebase_usage,
1524                                    builtin_rebase_options);
1525
1526         options.allow_empty_message = 1;
1527         git_config(rebase_config, &options);
1528
1529         if (options.use_legacy_rebase ||
1530             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1531                 warning(_("the rebase.useBuiltin support has been removed!\n"
1532                           "See its entry in 'git help config' for details."));
1533
1534         strbuf_reset(&buf);
1535         strbuf_addf(&buf, "%s/applying", apply_dir());
1536         if(file_exists(buf.buf))
1537                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1538
1539         if (is_directory(apply_dir())) {
1540                 options.type = REBASE_AM;
1541                 options.state_dir = apply_dir();
1542         } else if (is_directory(merge_dir())) {
1543                 strbuf_reset(&buf);
1544                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1545                 if (is_directory(buf.buf)) {
1546                         options.type = REBASE_PRESERVE_MERGES;
1547                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1548                 } else {
1549                         strbuf_reset(&buf);
1550                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1551                         if(file_exists(buf.buf)) {
1552                                 options.type = REBASE_INTERACTIVE;
1553                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1554                         } else
1555                                 options.type = REBASE_MERGE;
1556                 }
1557                 options.state_dir = merge_dir();
1558         }
1559
1560         if (options.type != REBASE_UNSPECIFIED)
1561                 in_progress = 1;
1562
1563         total_argc = argc;
1564         argc = parse_options(argc, argv, prefix,
1565                              builtin_rebase_options,
1566                              builtin_rebase_usage, 0);
1567
1568         if (action != ACTION_NONE && total_argc != 2) {
1569                 usage_with_options(builtin_rebase_usage,
1570                                    builtin_rebase_options);
1571         }
1572
1573         if (argc > 2)
1574                 usage_with_options(builtin_rebase_usage,
1575                                    builtin_rebase_options);
1576
1577         if (options.type == REBASE_PRESERVE_MERGES)
1578                 warning(_("git rebase --preserve-merges is deprecated. "
1579                           "Use --rebase-merges instead."));
1580
1581         if (keep_base) {
1582                 if (options.onto_name)
1583                         die(_("cannot combine '--keep-base' with '--onto'"));
1584                 if (options.root)
1585                         die(_("cannot combine '--keep-base' with '--root'"));
1586         }
1587
1588         if (action != ACTION_NONE && !in_progress)
1589                 die(_("No rebase in progress?"));
1590         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1591
1592         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1593                 die(_("The --edit-todo action can only be used during "
1594                       "interactive rebase."));
1595
1596         if (trace2_is_enabled()) {
1597                 if (is_interactive(&options))
1598                         trace2_cmd_mode("interactive");
1599                 else if (exec.nr)
1600                         trace2_cmd_mode("interactive-exec");
1601                 else
1602                         trace2_cmd_mode(action_names[action]);
1603         }
1604
1605         switch (action) {
1606         case ACTION_CONTINUE: {
1607                 struct object_id head;
1608                 struct lock_file lock_file = LOCK_INIT;
1609                 int fd;
1610
1611                 options.action = "continue";
1612                 set_reflog_action(&options);
1613
1614                 /* Sanity check */
1615                 if (get_oid("HEAD", &head))
1616                         die(_("Cannot read HEAD"));
1617
1618                 fd = hold_locked_index(&lock_file, 0);
1619                 if (repo_read_index(the_repository) < 0)
1620                         die(_("could not read index"));
1621                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1622                               NULL);
1623                 if (0 <= fd)
1624                         repo_update_index_if_able(the_repository, &lock_file);
1625                 rollback_lock_file(&lock_file);
1626
1627                 if (has_unstaged_changes(the_repository, 1)) {
1628                         puts(_("You must edit all merge conflicts and then\n"
1629                                "mark them as resolved using git add"));
1630                         exit(1);
1631                 }
1632                 if (read_basic_state(&options))
1633                         exit(1);
1634                 goto run_rebase;
1635         }
1636         case ACTION_SKIP: {
1637                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1638
1639                 options.action = "skip";
1640                 set_reflog_action(&options);
1641
1642                 rerere_clear(the_repository, &merge_rr);
1643                 string_list_clear(&merge_rr, 1);
1644
1645                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1646                                NULL, NULL) < 0)
1647                         die(_("could not discard worktree changes"));
1648                 remove_branch_state(the_repository, 0);
1649                 if (read_basic_state(&options))
1650                         exit(1);
1651                 goto run_rebase;
1652         }
1653         case ACTION_ABORT: {
1654                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1655                 options.action = "abort";
1656                 set_reflog_action(&options);
1657
1658                 rerere_clear(the_repository, &merge_rr);
1659                 string_list_clear(&merge_rr, 1);
1660
1661                 if (read_basic_state(&options))
1662                         exit(1);
1663                 if (reset_head(&options.orig_head, "reset",
1664                                options.head_name, RESET_HEAD_HARD,
1665                                NULL, NULL) < 0)
1666                         die(_("could not move back to %s"),
1667                             oid_to_hex(&options.orig_head));
1668                 remove_branch_state(the_repository, 0);
1669                 ret = !!finish_rebase(&options);
1670                 goto cleanup;
1671         }
1672         case ACTION_QUIT: {
1673                 if (options.type == REBASE_INTERACTIVE) {
1674                         struct replay_opts replay = REPLAY_OPTS_INIT;
1675
1676                         replay.action = REPLAY_INTERACTIVE_REBASE;
1677                         ret = !!sequencer_remove_state(&replay);
1678                 } else {
1679                         strbuf_reset(&buf);
1680                         strbuf_addstr(&buf, options.state_dir);
1681                         ret = !!remove_dir_recursively(&buf, 0);
1682                         if (ret)
1683                                 error(_("could not remove '%s'"),
1684                                        options.state_dir);
1685                 }
1686                 goto cleanup;
1687         }
1688         case ACTION_EDIT_TODO:
1689                 options.action = "edit-todo";
1690                 options.dont_finish_rebase = 1;
1691                 goto run_rebase;
1692         case ACTION_SHOW_CURRENT_PATCH:
1693                 options.action = "show-current-patch";
1694                 options.dont_finish_rebase = 1;
1695                 goto run_rebase;
1696         case ACTION_NONE:
1697                 break;
1698         default:
1699                 BUG("action: %d", action);
1700         }
1701
1702         /* Make sure no rebase is in progress */
1703         if (in_progress) {
1704                 const char *last_slash = strrchr(options.state_dir, '/');
1705                 const char *state_dir_base =
1706                         last_slash ? last_slash + 1 : options.state_dir;
1707                 const char *cmd_live_rebase =
1708                         "git rebase (--continue | --abort | --skip)";
1709                 strbuf_reset(&buf);
1710                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1711                 die(_("It seems that there is already a %s directory, and\n"
1712                       "I wonder if you are in the middle of another rebase.  "
1713                       "If that is the\n"
1714                       "case, please try\n\t%s\n"
1715                       "If that is not the case, please\n\t%s\n"
1716                       "and run me again.  I am stopping in case you still "
1717                       "have something\n"
1718                       "valuable there.\n"),
1719                     state_dir_base, cmd_live_rebase, buf.buf);
1720         }
1721
1722         for (i = 0; i < options.git_am_opts.argc; i++) {
1723                 const char *option = options.git_am_opts.argv[i], *p;
1724                 if (!strcmp(option, "--committer-date-is-author-date") ||
1725                     !strcmp(option, "--ignore-date") ||
1726                     !strcmp(option, "--whitespace=fix") ||
1727                     !strcmp(option, "--whitespace=strip"))
1728                         options.flags |= REBASE_FORCE;
1729                 else if (skip_prefix(option, "-C", &p)) {
1730                         while (*p)
1731                                 if (!isdigit(*(p++)))
1732                                         die(_("switch `C' expects a "
1733                                               "numerical value"));
1734                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1735                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1736                             strcmp(p, "error") && strcmp(p, "error-all"))
1737                                 die("Invalid whitespace option: '%s'", p);
1738                 }
1739         }
1740
1741         for (i = 0; i < exec.nr; i++)
1742                 if (check_exec_cmd(exec.items[i].string))
1743                         exit(1);
1744
1745         if (!(options.flags & REBASE_NO_QUIET))
1746                 argv_array_push(&options.git_am_opts, "-q");
1747
1748         if (options.keep_empty)
1749                 imply_interactive(&options, "--keep-empty");
1750
1751         if (gpg_sign) {
1752                 free(options.gpg_sign_opt);
1753                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1754         }
1755
1756         if (exec.nr) {
1757                 int i;
1758
1759                 imply_interactive(&options, "--exec");
1760
1761                 strbuf_reset(&buf);
1762                 for (i = 0; i < exec.nr; i++)
1763                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1764                 options.cmd = xstrdup(buf.buf);
1765         }
1766
1767         if (rebase_merges) {
1768                 if (!*rebase_merges)
1769                         ; /* default mode; do nothing */
1770                 else if (!strcmp("rebase-cousins", rebase_merges))
1771                         options.rebase_cousins = 1;
1772                 else if (strcmp("no-rebase-cousins", rebase_merges))
1773                         die(_("Unknown mode: %s"), rebase_merges);
1774                 options.rebase_merges = 1;
1775                 imply_interactive(&options, "--rebase-merges");
1776         }
1777
1778         if (strategy_options.nr) {
1779                 int i;
1780
1781                 if (!options.strategy)
1782                         options.strategy = "recursive";
1783
1784                 strbuf_reset(&buf);
1785                 for (i = 0; i < strategy_options.nr; i++)
1786                         strbuf_addf(&buf, " --%s",
1787                                     strategy_options.items[i].string);
1788                 options.strategy_opts = xstrdup(buf.buf);
1789         }
1790
1791         if (options.strategy) {
1792                 options.strategy = xstrdup(options.strategy);
1793                 switch (options.type) {
1794                 case REBASE_AM:
1795                         die(_("--strategy requires --merge or --interactive"));
1796                 case REBASE_MERGE:
1797                 case REBASE_INTERACTIVE:
1798                 case REBASE_PRESERVE_MERGES:
1799                         /* compatible */
1800                         break;
1801                 case REBASE_UNSPECIFIED:
1802                         options.type = REBASE_MERGE;
1803                         break;
1804                 default:
1805                         BUG("unhandled rebase type (%d)", options.type);
1806                 }
1807         }
1808
1809         if (options.type == REBASE_MERGE)
1810                 imply_interactive(&options, "--merge");
1811
1812         if (options.root && !options.onto_name)
1813                 imply_interactive(&options, "--root without --onto");
1814
1815         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1816                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1817
1818         switch (options.type) {
1819         case REBASE_MERGE:
1820         case REBASE_INTERACTIVE:
1821         case REBASE_PRESERVE_MERGES:
1822                 options.state_dir = merge_dir();
1823                 break;
1824         case REBASE_AM:
1825                 options.state_dir = apply_dir();
1826                 break;
1827         default:
1828                 /* the default rebase backend is `--am` */
1829                 options.type = REBASE_AM;
1830                 options.state_dir = apply_dir();
1831                 break;
1832         }
1833
1834         if (reschedule_failed_exec > 0 && !is_interactive(&options))
1835                 die(_("--reschedule-failed-exec requires "
1836                       "--exec or --interactive"));
1837         if (reschedule_failed_exec >= 0)
1838                 options.reschedule_failed_exec = reschedule_failed_exec;
1839
1840         if (options.git_am_opts.argc) {
1841                 /* all am options except -q are compatible only with --am */
1842                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1843                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1844                                 break;
1845
1846                 if (is_interactive(&options) && i >= 0)
1847                         die(_("cannot combine am options with either "
1848                               "interactive or merge options"));
1849         }
1850
1851         if (options.signoff) {
1852                 if (options.type == REBASE_PRESERVE_MERGES)
1853                         die("cannot combine '--signoff' with "
1854                             "'--preserve-merges'");
1855                 argv_array_push(&options.git_am_opts, "--signoff");
1856                 options.flags |= REBASE_FORCE;
1857         }
1858
1859         if (options.type == REBASE_PRESERVE_MERGES) {
1860                 /*
1861                  * Note: incompatibility with --signoff handled in signoff block above
1862                  * Note: incompatibility with --interactive is just a strong warning;
1863                  *       git-rebase.txt caveats with "unless you know what you are doing"
1864                  */
1865                 if (options.rebase_merges)
1866                         die(_("cannot combine '--preserve-merges' with "
1867                               "'--rebase-merges'"));
1868
1869                 if (options.reschedule_failed_exec)
1870                         die(_("error: cannot combine '--preserve-merges' with "
1871                               "'--reschedule-failed-exec'"));
1872         }
1873
1874         if (!options.root) {
1875                 if (argc < 1) {
1876                         struct branch *branch;
1877
1878                         branch = branch_get(NULL);
1879                         options.upstream_name = branch_get_upstream(branch,
1880                                                                     NULL);
1881                         if (!options.upstream_name)
1882                                 error_on_missing_default_upstream();
1883                         if (fork_point < 0)
1884                                 fork_point = 1;
1885                 } else {
1886                         options.upstream_name = argv[0];
1887                         argc--;
1888                         argv++;
1889                         if (!strcmp(options.upstream_name, "-"))
1890                                 options.upstream_name = "@{-1}";
1891                 }
1892                 options.upstream = peel_committish(options.upstream_name);
1893                 if (!options.upstream)
1894                         die(_("invalid upstream '%s'"), options.upstream_name);
1895                 options.upstream_arg = options.upstream_name;
1896         } else {
1897                 if (!options.onto_name) {
1898                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1899                                         &squash_onto, NULL, NULL) < 0)
1900                                 die(_("Could not create new root commit"));
1901                         options.squash_onto = &squash_onto;
1902                         options.onto_name = squash_onto_name =
1903                                 xstrdup(oid_to_hex(&squash_onto));
1904                 } else
1905                         options.root_with_onto = 1;
1906
1907                 options.upstream_name = NULL;
1908                 options.upstream = NULL;
1909                 if (argc > 1)
1910                         usage_with_options(builtin_rebase_usage,
1911                                            builtin_rebase_options);
1912                 options.upstream_arg = "--root";
1913         }
1914
1915         /* Make sure the branch to rebase onto is valid. */
1916         if (keep_base) {
1917                 strbuf_reset(&buf);
1918                 strbuf_addstr(&buf, options.upstream_name);
1919                 strbuf_addstr(&buf, "...");
1920                 options.onto_name = xstrdup(buf.buf);
1921         } else if (!options.onto_name)
1922                 options.onto_name = options.upstream_name;
1923         if (strstr(options.onto_name, "...")) {
1924                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
1925                         if (keep_base)
1926                                 die(_("'%s': need exactly one merge base with branch"),
1927                                     options.upstream_name);
1928                         else
1929                                 die(_("'%s': need exactly one merge base"),
1930                                     options.onto_name);
1931                 }
1932                 options.onto = lookup_commit_or_die(&merge_base,
1933                                                     options.onto_name);
1934         } else {
1935                 options.onto = peel_committish(options.onto_name);
1936                 if (!options.onto)
1937                         die(_("Does not point to a valid commit '%s'"),
1938                                 options.onto_name);
1939         }
1940
1941         /*
1942          * If the branch to rebase is given, that is the branch we will rebase
1943          * branch_name -- branch/commit being rebased, or
1944          *                HEAD (already detached)
1945          * orig_head -- commit object name of tip of the branch before rebasing
1946          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1947          */
1948         if (argc == 1) {
1949                 /* Is it "rebase other branchname" or "rebase other commit"? */
1950                 branch_name = argv[0];
1951                 options.switch_to = argv[0];
1952
1953                 /* Is it a local branch? */
1954                 strbuf_reset(&buf);
1955                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1956                 if (!read_ref(buf.buf, &options.orig_head)) {
1957                         die_if_checked_out(buf.buf, 1);
1958                         options.head_name = xstrdup(buf.buf);
1959                 /* If not is it a valid ref (branch or commit)? */
1960                 } else if (!get_oid(branch_name, &options.orig_head))
1961                         options.head_name = NULL;
1962                 else
1963                         die(_("fatal: no such branch/commit '%s'"),
1964                             branch_name);
1965         } else if (argc == 0) {
1966                 /* Do not need to switch branches, we are already on it. */
1967                 options.head_name =
1968                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1969                                          &flags));
1970                 if (!options.head_name)
1971                         die(_("No such ref: %s"), "HEAD");
1972                 if (flags & REF_ISSYMREF) {
1973                         if (!skip_prefix(options.head_name,
1974                                          "refs/heads/", &branch_name))
1975                                 branch_name = options.head_name;
1976
1977                 } else {
1978                         FREE_AND_NULL(options.head_name);
1979                         branch_name = "HEAD";
1980                 }
1981                 if (get_oid("HEAD", &options.orig_head))
1982                         die(_("Could not resolve HEAD to a revision"));
1983         } else
1984                 BUG("unexpected number of arguments left to parse");
1985
1986         if (fork_point > 0) {
1987                 struct commit *head =
1988                         lookup_commit_reference(the_repository,
1989                                                 &options.orig_head);
1990                 options.restrict_revision =
1991                         get_fork_point(options.upstream_name, head);
1992         }
1993
1994         if (repo_read_index(the_repository) < 0)
1995                 die(_("could not read index"));
1996
1997         if (options.autostash) {
1998                 struct lock_file lock_file = LOCK_INIT;
1999                 int fd;
2000
2001                 fd = hold_locked_index(&lock_file, 0);
2002                 refresh_cache(REFRESH_QUIET);
2003                 if (0 <= fd)
2004                         repo_update_index_if_able(the_repository, &lock_file);
2005                 rollback_lock_file(&lock_file);
2006
2007                 if (has_unstaged_changes(the_repository, 1) ||
2008                     has_uncommitted_changes(the_repository, 1)) {
2009                         const char *autostash =
2010                                 state_dir_path("autostash", &options);
2011                         struct child_process stash = CHILD_PROCESS_INIT;
2012                         struct object_id oid;
2013
2014                         argv_array_pushl(&stash.args,
2015                                          "stash", "create", "autostash", NULL);
2016                         stash.git_cmd = 1;
2017                         stash.no_stdin = 1;
2018                         strbuf_reset(&buf);
2019                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
2020                                 die(_("Cannot autostash"));
2021                         strbuf_trim_trailing_newline(&buf);
2022                         if (get_oid(buf.buf, &oid))
2023                                 die(_("Unexpected stash response: '%s'"),
2024                                     buf.buf);
2025                         strbuf_reset(&buf);
2026                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
2027
2028                         if (safe_create_leading_directories_const(autostash))
2029                                 die(_("Could not create directory for '%s'"),
2030                                     options.state_dir);
2031                         write_file(autostash, "%s", oid_to_hex(&oid));
2032                         printf(_("Created autostash: %s\n"), buf.buf);
2033                         if (reset_head(NULL, "reset --hard",
2034                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2035                                 die(_("could not reset --hard"));
2036
2037                         if (discard_index(the_repository->index) < 0 ||
2038                                 repo_read_index(the_repository) < 0)
2039                                 die(_("could not read index"));
2040                 }
2041         }
2042
2043         if (require_clean_work_tree(the_repository, "rebase",
2044                                     _("Please commit or stash them."), 1, 1)) {
2045                 ret = 1;
2046                 goto cleanup;
2047         }
2048
2049         /*
2050          * Now we are rebasing commits upstream..orig_head (or with --root,
2051          * everything leading up to orig_head) on top of onto.
2052          */
2053
2054         /*
2055          * Check if we are already based on onto with linear history,
2056          * in which case we could fast-forward without replacing the commits
2057          * with new commits recreated by replaying their changes. This
2058          * optimization must not be done if this is an interactive rebase.
2059          */
2060         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
2061                     &options.orig_head, &merge_base) &&
2062             !is_interactive(&options)) {
2063                 int flag;
2064
2065                 if (!(options.flags & REBASE_FORCE)) {
2066                         /* Lazily switch to the target branch if needed... */
2067                         if (options.switch_to) {
2068                                 struct object_id oid;
2069
2070                                 if (get_oid(options.switch_to, &oid) < 0) {
2071                                         ret = !!error(_("could not parse '%s'"),
2072                                                       options.switch_to);
2073                                         goto cleanup;
2074                                 }
2075
2076                                 strbuf_reset(&buf);
2077                                 strbuf_addf(&buf, "%s: checkout %s",
2078                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2079                                             options.switch_to);
2080                                 if (reset_head(&oid, "checkout",
2081                                                options.head_name,
2082                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2083                                                NULL, buf.buf) < 0) {
2084                                         ret = !!error(_("could not switch to "
2085                                                         "%s"),
2086                                                       options.switch_to);
2087                                         goto cleanup;
2088                                 }
2089                         }
2090
2091                         if (!(options.flags & REBASE_NO_QUIET))
2092                                 ; /* be quiet */
2093                         else if (!strcmp(branch_name, "HEAD") &&
2094                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2095                                 puts(_("HEAD is up to date."));
2096                         else
2097                                 printf(_("Current branch %s is up to date.\n"),
2098                                        branch_name);
2099                         ret = !!finish_rebase(&options);
2100                         goto cleanup;
2101                 } else if (!(options.flags & REBASE_NO_QUIET))
2102                         ; /* be quiet */
2103                 else if (!strcmp(branch_name, "HEAD") &&
2104                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2105                         puts(_("HEAD is up to date, rebase forced."));
2106                 else
2107                         printf(_("Current branch %s is up to date, rebase "
2108                                  "forced.\n"), branch_name);
2109         }
2110
2111         /* If a hook exists, give it a chance to interrupt*/
2112         if (!ok_to_skip_pre_rebase &&
2113             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2114                         argc ? argv[0] : NULL, NULL))
2115                 die(_("The pre-rebase hook refused to rebase."));
2116
2117         if (options.flags & REBASE_DIFFSTAT) {
2118                 struct diff_options opts;
2119
2120                 if (options.flags & REBASE_VERBOSE) {
2121                         if (is_null_oid(&merge_base))
2122                                 printf(_("Changes to %s:\n"),
2123                                        oid_to_hex(&options.onto->object.oid));
2124                         else
2125                                 printf(_("Changes from %s to %s:\n"),
2126                                        oid_to_hex(&merge_base),
2127                                        oid_to_hex(&options.onto->object.oid));
2128                 }
2129
2130                 /* We want color (if set), but no pager */
2131                 diff_setup(&opts);
2132                 opts.stat_width = -1; /* use full terminal width */
2133                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2134                 opts.output_format |=
2135                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2136                 opts.detect_rename = DIFF_DETECT_RENAME;
2137                 diff_setup_done(&opts);
2138                 diff_tree_oid(is_null_oid(&merge_base) ?
2139                               the_hash_algo->empty_tree : &merge_base,
2140                               &options.onto->object.oid, "", &opts);
2141                 diffcore_std(&opts);
2142                 diff_flush(&opts);
2143         }
2144
2145         if (is_interactive(&options))
2146                 goto run_rebase;
2147
2148         /* Detach HEAD and reset the tree */
2149         if (options.flags & REBASE_NO_QUIET)
2150                 printf(_("First, rewinding head to replay your work on top of "
2151                          "it...\n"));
2152
2153         strbuf_addf(&msg, "%s: checkout %s",
2154                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2155         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2156                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2157                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2158                        NULL, msg.buf))
2159                 die(_("Could not detach HEAD"));
2160         strbuf_release(&msg);
2161
2162         /*
2163          * If the onto is a proper descendant of the tip of the branch, then
2164          * we just fast-forwarded.
2165          */
2166         strbuf_reset(&msg);
2167         if (oideq(&merge_base, &options.orig_head)) {
2168                 printf(_("Fast-forwarded %s to %s.\n"),
2169                         branch_name, options.onto_name);
2170                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2171                         options.head_name ? options.head_name : "detached HEAD",
2172                         oid_to_hex(&options.onto->object.oid));
2173                 reset_head(NULL, "Fast-forwarded", options.head_name,
2174                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2175                 strbuf_release(&msg);
2176                 ret = !!finish_rebase(&options);
2177                 goto cleanup;
2178         }
2179
2180         strbuf_addf(&revisions, "%s..%s",
2181                     options.root ? oid_to_hex(&options.onto->object.oid) :
2182                     (options.restrict_revision ?
2183                      oid_to_hex(&options.restrict_revision->object.oid) :
2184                      oid_to_hex(&options.upstream->object.oid)),
2185                     oid_to_hex(&options.orig_head));
2186
2187         options.revisions = revisions.buf;
2188
2189 run_rebase:
2190         ret = !!run_specific_rebase(&options, action);
2191
2192 cleanup:
2193         strbuf_release(&buf);
2194         strbuf_release(&revisions);
2195         free(options.head_name);
2196         free(options.gpg_sign_opt);
2197         free(options.cmd);
2198         free(squash_onto_name);
2199         return ret;
2200 }