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 enum empty_type {
  54         EMPTY_UNSPECIFIED = -1,
  55         EMPTY_DROP,
  56         EMPTY_KEEP,
  57         EMPTY_ASK
  58 };
  59
  60 struct rebase_options {
  61         enum rebase_type type;
  62         enum empty_type empty;
  63         const char *default_backend;
  64         const char *state_dir;
  65         struct commit *upstream;
  66         const char *upstream_name;
  67         const char *upstream_arg;
  68         char *head_name;
  69         struct object_id orig_head;
  70         struct commit *onto;
  71         const char *onto_name;
  72         const char *revisions;
  73         const char *switch_to;
  74         int root, root_with_onto;
  75         struct object_id *squash_onto;
  76         struct commit *restrict_revision;
  77         int dont_finish_rebase;
  78         enum {
  79                 REBASE_NO_QUIET = 1<<0,
  80                 REBASE_VERBOSE = 1<<1,
  81                 REBASE_DIFFSTAT = 1<<2,
  82                 REBASE_FORCE = 1<<3,
  83                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  84         } flags;
  85         struct argv_array git_am_opts;
  86         const char *action;
  87         int signoff;
  88         int allow_rerere_autoupdate;
  89         int autosquash;
  90         char *gpg_sign_opt;
  91         int autostash;
  92         char *cmd;
  93         int allow_empty_message;
  94         int rebase_merges, rebase_cousins;
  95         char *strategy, *strategy_opts;
  96         struct strbuf git_format_patch_opt;
  97         int reschedule_failed_exec;
  98         int use_legacy_rebase;
  99 };
 100
 101 #define REBASE_OPTIONS_INIT {                           \
 102                 .type = REBASE_UNSPECIFIED,             \
 103                 .empty = EMPTY_UNSPECIFIED,             \
 104                 .default_backend = "merge",             \
 105                 .flags = REBASE_NO_QUIET,               \
 106                 .git_am_opts = ARGV_ARRAY_INIT,         \
 107                 .git_format_patch_opt = STRBUF_INIT     \
 108         }
 109
 110 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 111 {
 112         struct replay_opts replay = REPLAY_OPTS_INIT;
 113
 114         replay.action = REPLAY_INTERACTIVE_REBASE;
 115         sequencer_init_config(&replay);
 116
 117         replay.signoff = opts->signoff;
 118         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 119         if (opts->allow_rerere_autoupdate)
 120                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 121         replay.allow_empty = 1;
 122         replay.allow_empty_message = opts->allow_empty_message;
 123         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
 124         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
 125         replay.quiet = !(opts->flags & REBASE_NO_QUIET);
 126         replay.verbose = opts->flags & REBASE_VERBOSE;
 127         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 128         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 129         replay.strategy = opts->strategy;
 130         if (opts->strategy_opts)
 131                 parse_strategy_opts(&replay, opts->strategy_opts);
 132
 133         if (opts->squash_onto) {
 134                 oidcpy(&replay.squash_onto, opts->squash_onto);
 135                 replay.have_squash_onto = 1;
 136         }
 137
 138         return replay;
 139 }
 140
 141 enum action {
 142         ACTION_NONE = 0,
 143         ACTION_CONTINUE,
 144         ACTION_SKIP,
 145         ACTION_ABORT,
 146         ACTION_QUIT,
 147         ACTION_EDIT_TODO,
 148         ACTION_SHOW_CURRENT_PATCH,
 149         ACTION_SHORTEN_OIDS,
 150         ACTION_EXPAND_OIDS,
 151         ACTION_CHECK_TODO_LIST,
 152         ACTION_REARRANGE_SQUASH,
 153         ACTION_ADD_EXEC
 154 };
 155
 156 static const char *action_names[] = { "undefined",
 157                                       "continue",
 158                                       "skip",
 159                                       "abort",
 160                                       "quit",
 161                                       "edit_todo",
 162                                       "show_current_patch" };
 163
 164 static int add_exec_commands(struct string_list *commands)
 165 {
 166         const char *todo_file = rebase_path_todo();
 167         struct todo_list todo_list = TODO_LIST_INIT;
 168         int res;
 169
 170         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 171                 return error_errno(_("could not read '%s'."), todo_file);
 172
 173         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 174                                         &todo_list)) {
 175                 todo_list_release(&todo_list);
 176                 return error(_("unusable todo list: '%s'"), todo_file);
 177         }
 178
 179         todo_list_add_exec_commands(&todo_list, commands);
 180         res = todo_list_write_to_file(the_repository, &todo_list,
 181                                       todo_file, NULL, NULL, -1, 0);
 182         todo_list_release(&todo_list);
 183
 184         if (res)
 185                 return error_errno(_("could not write '%s'."), todo_file);
 186         return 0;
 187 }
 188
 189 static int rearrange_squash_in_todo_file(void)
 190 {
 191         const char *todo_file = rebase_path_todo();
 192         struct todo_list todo_list = TODO_LIST_INIT;
 193         int res = 0;
 194
 195         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 196                 return error_errno(_("could not read '%s'."), todo_file);
 197         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 198                                         &todo_list)) {
 199                 todo_list_release(&todo_list);
 200                 return error(_("unusable todo list: '%s'"), todo_file);
 201         }
 202
 203         res = todo_list_rearrange_squash(&todo_list);
 204         if (!res)
 205                 res = todo_list_write_to_file(the_repository, &todo_list,
 206                                               todo_file, NULL, NULL, -1, 0);
 207
 208         todo_list_release(&todo_list);
 209
 210         if (res)
 211                 return error_errno(_("could not write '%s'."), todo_file);
 212         return 0;
 213 }
 214
 215 static int transform_todo_file(unsigned flags)
 216 {
 217         const char *todo_file = rebase_path_todo();
 218         struct todo_list todo_list = TODO_LIST_INIT;
 219         int res;
 220
 221         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 222                 return error_errno(_("could not read '%s'."), todo_file);
 223
 224         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 225                                         &todo_list)) {
 226                 todo_list_release(&todo_list);
 227                 return error(_("unusable todo list: '%s'"), todo_file);
 228         }
 229
 230         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 231                                       NULL, NULL, -1, flags);
 232         todo_list_release(&todo_list);
 233
 234         if (res)
 235                 return error_errno(_("could not write '%s'."), todo_file);
 236         return 0;
 237 }
 238
 239 static int edit_todo_file(unsigned flags)
 240 {
 241         const char *todo_file = rebase_path_todo();
 242         struct todo_list todo_list = TODO_LIST_INIT,
 243                 new_todo = TODO_LIST_INIT;
 244         int res = 0;
 245
 246         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 247                 return error_errno(_("could not read '%s'."), todo_file);
 248
 249         strbuf_stripspace(&todo_list.buf, 1);
 250         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 251         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 252                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 253                 res = error_errno(_("could not write '%s'"), todo_file);
 254
 255         todo_list_release(&todo_list);
 256         todo_list_release(&new_todo);
 257
 258         return res;
 259 }
 260
 261 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 262                                const char **head_hash,
 263                                char **revisions, char **shortrevisions)
 264 {
 265         struct commit *base_rev = upstream ? upstream : onto;
 266         const char *shorthead;
 267         struct object_id orig_head;
 268
 269         if (get_oid("HEAD", &orig_head))
 270                 return error(_("no HEAD?"));
 271
 272         *head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
 273         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 274                                                    *head_hash);
 275
 276         shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
 277
 278         if (upstream) {
 279                 const char *shortrev;
 280
 281                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 282                                               DEFAULT_ABBREV);
 283
 284                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 285         } else
 286                 *shortrevisions = xstrdup(shorthead);
 287
 288         return 0;
 289 }
 290
 291 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 292                             struct commit *onto, const char *orig_head)
 293 {
 294         FILE *interactive;
 295
 296         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 297                 return error_errno(_("could not create temporary %s"), merge_dir());
 298
 299         delete_reflog("REBASE_HEAD");
 300
 301         interactive = fopen(path_interactive(), "w");
 302         if (!interactive)
 303                 return error_errno(_("could not mark as interactive"));
 304         fclose(interactive);
 305
 306         return write_basic_state(opts, head_name, onto, orig_head);
 307 }
 308
 309 static void split_exec_commands(const char *cmd, struct string_list *commands)
 310 {
 311         if (cmd && *cmd) {
 312                 string_list_split(commands, cmd, '\n', -1);
 313
 314                 /* rebase.c adds a new line to cmd after every command,
 315                  * so here the last command is always empty */
 316                 string_list_remove_empty_items(commands, 0);
 317         }
 318 }
 319
 320 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 321 {
 322         int ret;
 323         const char *head_hash = NULL;
 324         char *revisions = NULL, *shortrevisions = NULL;
 325         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 326         struct todo_list todo_list = TODO_LIST_INIT;
 327         struct replay_opts replay = get_replay_opts(opts);
 328         struct string_list commands = STRING_LIST_INIT_DUP;
 329
 330         if (prepare_branch_to_be_rebased(the_repository, &replay,
 331                                          opts->switch_to))
 332                 return -1;
 333
 334         if (get_revision_ranges(opts->upstream, opts->onto, &head_hash,
 335                                 &revisions, &shortrevisions))
 336                 return -1;
 337
 338         if (init_basic_state(&replay,
 339                              opts->head_name ? opts->head_name : "detached HEAD",
 340                              opts->onto, head_hash)) {
 341                 free(revisions);
 342                 free(shortrevisions);
 343
 344                 return -1;
 345         }
 346
 347         if (!opts->upstream && opts->squash_onto)
 348                 write_file(path_squash_onto(), "%s\n",
 349                            oid_to_hex(opts->squash_onto));
 350
 351         argv_array_pushl(&make_script_args, "", revisions, NULL);
 352         if (opts->restrict_revision)
 353                 argv_array_pushf(&make_script_args, "^%s",
 354                                  oid_to_hex(&opts->restrict_revision->object.oid));
 355
 356         ret = sequencer_make_script(the_repository, &todo_list.buf,
 357                                     make_script_args.argc, make_script_args.argv,
 358                                     flags);
 359
 360         if (ret)
 361                 error(_("could not generate todo list"));
 362         else {
 363                 discard_cache();
 364                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 365                                                 &todo_list))
 366                         BUG("unusable todo list");
 367
 368                 split_exec_commands(opts->cmd, &commands);
 369                 ret = complete_action(the_repository, &replay, flags,
 370                         shortrevisions, opts->onto_name, opts->onto, head_hash,
 371                         &commands, opts->autosquash, &todo_list);
 372         }
 373
 374         string_list_clear(&commands, 0);
 375         free(revisions);
 376         free(shortrevisions);
 377         todo_list_release(&todo_list);
 378         argv_array_clear(&make_script_args);
 379
 380         return ret;
 381 }
 382
 383 static int run_rebase_interactive(struct rebase_options *opts,
 384                                   enum action command)
 385 {
 386         unsigned flags = 0;
 387         int abbreviate_commands = 0, ret = 0;
 388
 389         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 390
 391         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 392         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 393         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 394         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 395         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 396
 397         switch (command) {
 398         case ACTION_NONE: {
 399                 if (!opts->onto && !opts->upstream)
 400                         die(_("a base commit must be provided with --upstream or --onto"));
 401
 402                 ret = do_interactive_rebase(opts, flags);
 403                 break;
 404         }
 405         case ACTION_SKIP: {
 406                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 407
 408                 rerere_clear(the_repository, &merge_rr);
 409         }
 410                 /* fallthrough */
 411         case ACTION_CONTINUE: {
 412                 struct replay_opts replay_opts = get_replay_opts(opts);
 413
 414                 ret = sequencer_continue(the_repository, &replay_opts);
 415                 break;
 416         }
 417         case ACTION_EDIT_TODO:
 418                 ret = edit_todo_file(flags);
 419                 break;
 420         case ACTION_SHOW_CURRENT_PATCH: {
 421                 struct child_process cmd = CHILD_PROCESS_INIT;
 422
 423                 cmd.git_cmd = 1;
 424                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 425                 ret = run_command(&cmd);
 426
 427                 break;
 428         }
 429         case ACTION_SHORTEN_OIDS:
 430         case ACTION_EXPAND_OIDS:
 431                 ret = transform_todo_file(flags);
 432                 break;
 433         case ACTION_CHECK_TODO_LIST:
 434                 ret = check_todo_list_from_file(the_repository);
 435                 break;
 436         case ACTION_REARRANGE_SQUASH:
 437                 ret = rearrange_squash_in_todo_file();
 438                 break;
 439         case ACTION_ADD_EXEC: {
 440                 struct string_list commands = STRING_LIST_INIT_DUP;
 441
 442                 split_exec_commands(opts->cmd, &commands);
 443                 ret = add_exec_commands(&commands);
 444                 string_list_clear(&commands, 0);
 445                 break;
 446         }
 447         default:
 448                 BUG("invalid command '%d'", command);
 449         }
 450
 451         return ret;
 452 }
 453
 454 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 455                                 int unset)
 456 {
 457         struct rebase_options *opts = opt->value;
 458
 459         BUG_ON_OPT_ARG(arg);
 460
 461         /*
 462          * If we ever want to remap --keep-empty to --empty=keep, insert:
 463          *      opts->empty = unset ? EMPTY_UNSPECIFIED : EMPTY_KEEP;
 464          */
 465         opts->type = REBASE_INTERACTIVE;
 466         return 0;
 467 }
 468
 469 static const char * const builtin_rebase_interactive_usage[] = {
 470         N_("git rebase--interactive [<options>]"),
 471         NULL
 472 };
 473
 474 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 475 {
 476         struct rebase_options opts = REBASE_OPTIONS_INIT;
 477         struct object_id squash_onto = null_oid;
 478         enum action command = ACTION_NONE;
 479         struct option options[] = {
 480                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 481                            REBASE_FORCE),
 482                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
 483                         N_("(DEPRECATED) keep empty commits"),
 484                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
 485                         parse_opt_keep_empty },
 486                 OPT_BOOL_F(0, "allow-empty-message", &opts.allow_empty_message,
 487                            N_("allow commits with empty messages"),
 488                            PARSE_OPT_HIDDEN),
 489                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 490                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 491                          N_("keep original branch points of cousins")),
 492                 OPT_BOOL(0, "autosquash", &opts.autosquash,
 493                          N_("move commits that begin with squash!/fixup!")),
 494                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 495                 OPT_BIT('v', "verbose", &opts.flags,
 496                         N_("display a diffstat of what changed upstream"),
 497                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 498                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 499                             ACTION_CONTINUE),
 500                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 501                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 502                             ACTION_EDIT_TODO),
 503                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 504                             ACTION_SHOW_CURRENT_PATCH),
 505                 OPT_CMDMODE(0, "shorten-ids", &command,
 506                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 507                 OPT_CMDMODE(0, "expand-ids", &command,
 508                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 509                 OPT_CMDMODE(0, "check-todo-list", &command,
 510                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 511                 OPT_CMDMODE(0, "rearrange-squash", &command,
 512                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 513                 OPT_CMDMODE(0, "add-exec-commands", &command,
 514                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 515                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 516                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 517                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 518                   N_("restrict-revision"), N_("restrict revision"),
 519                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 520                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 521                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 522                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 523                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 524                   0 },
 525                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 526                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 527                         N_("GPG-sign commits"),
 528                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 529                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 530                            N_("rebase strategy")),
 531                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 532                            N_("strategy options")),
 533                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 534                            N_("the branch or commit to checkout")),
 535                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 536                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 537                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 538                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 539                          N_("automatically re-schedule any `exec` that fails")),
 540                 OPT_END()
 541         };
 542
 543         opts.rebase_cousins = -1;
 544
 545         if (argc == 1)
 546                 usage_with_options(builtin_rebase_interactive_usage, options);
 547
 548         argc = parse_options(argc, argv, prefix, options,
 549                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 550
 551         if (!is_null_oid(&squash_onto))
 552                 opts.squash_onto = &squash_onto;
 553
 554         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 555                 warning(_("--[no-]rebase-cousins has no effect without "
 556                           "--rebase-merges"));
 557
 558         return !!run_rebase_interactive(&opts, command);
 559 }
 560
 561 static int is_interactive(struct rebase_options *opts)
 562 {
 563         return opts->type == REBASE_INTERACTIVE ||
 564                 opts->type == REBASE_PRESERVE_MERGES;
 565 }
 566
 567 static void imply_interactive(struct rebase_options *opts, const char *option)
 568 {
 569         switch (opts->type) {
 570         case REBASE_AM:
 571                 die(_("%s requires an interactive rebase"), option);
 572                 break;
 573         case REBASE_INTERACTIVE:
 574         case REBASE_PRESERVE_MERGES:
 575                 break;
 576         case REBASE_MERGE:
 577                 /* we now implement --merge via --interactive */
 578         default:
 579                 opts->type = REBASE_INTERACTIVE; /* implied */
 580                 break;
 581         }
 582 }
 583
 584 /* Returns the filename prefixed by the state_dir */
 585 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 586 {
 587         static struct strbuf path = STRBUF_INIT;
 588         static size_t prefix_len;
 589
 590         if (!prefix_len) {
 591                 strbuf_addf(&path, "%s/", opts->state_dir);
 592                 prefix_len = path.len;
 593         }
 594
 595         strbuf_setlen(&path, prefix_len);
 596         strbuf_addstr(&path, filename);
 597         return path.buf;
 598 }
 599
 600 /* Read one file, then strip line endings */
 601 static int read_one(const char *path, struct strbuf *buf)
 602 {
 603         if (strbuf_read_file(buf, path, 0) < 0)
 604                 return error_errno(_("could not read '%s'"), path);
 605         strbuf_trim_trailing_newline(buf);
 606         return 0;
 607 }
 608
 609 /* Initialize the rebase options from the state directory. */
 610 static int read_basic_state(struct rebase_options *opts)
 611 {
 612         struct strbuf head_name = STRBUF_INIT;
 613         struct strbuf buf = STRBUF_INIT;
 614         struct object_id oid;
 615
 616         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 617             read_one(state_dir_path("onto", opts), &buf))
 618                 return -1;
 619         opts->head_name = starts_with(head_name.buf, "refs/") ?
 620                 xstrdup(head_name.buf) : NULL;
 621         strbuf_release(&head_name);
 622         if (get_oid(buf.buf, &oid))
 623                 return error(_("could not get 'onto': '%s'"), buf.buf);
 624         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 625
 626         /*
 627          * We always write to orig-head, but interactive rebase used to write to
 628          * head. Fall back to reading from head to cover for the case that the
 629          * user upgraded git with an ongoing interactive rebase.
 630          */
 631         strbuf_reset(&buf);
 632         if (file_exists(state_dir_path("orig-head", opts))) {
 633                 if (read_one(state_dir_path("orig-head", opts), &buf))
 634                         return -1;
 635         } else if (read_one(state_dir_path("head", opts), &buf))
 636                 return -1;
 637         if (get_oid(buf.buf, &opts->orig_head))
 638                 return error(_("invalid orig-head: '%s'"), buf.buf);
 639
 640         if (file_exists(state_dir_path("quiet", opts)))
 641                 opts->flags &= ~REBASE_NO_QUIET;
 642         else
 643                 opts->flags |= REBASE_NO_QUIET;
 644
 645         if (file_exists(state_dir_path("verbose", opts)))
 646                 opts->flags |= REBASE_VERBOSE;
 647
 648         if (file_exists(state_dir_path("signoff", opts))) {
 649                 opts->signoff = 1;
 650                 opts->flags |= REBASE_FORCE;
 651         }
 652
 653         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 654                 strbuf_reset(&buf);
 655                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 656                             &buf))
 657                         return -1;
 658                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 659                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 660                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 661                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 662                 else
 663                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 664                                   "'%s'"), buf.buf);
 665         }
 666
 667         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 668                 strbuf_reset(&buf);
 669                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 670                             &buf))
 671                         return -1;
 672                 free(opts->gpg_sign_opt);
 673                 opts->gpg_sign_opt = xstrdup(buf.buf);
 674         }
 675
 676         if (file_exists(state_dir_path("strategy", opts))) {
 677                 strbuf_reset(&buf);
 678                 if (read_one(state_dir_path("strategy", opts), &buf))
 679                         return -1;
 680                 free(opts->strategy);
 681                 opts->strategy = xstrdup(buf.buf);
 682         }
 683
 684         if (file_exists(state_dir_path("strategy_opts", opts))) {
 685                 strbuf_reset(&buf);
 686                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 687                         return -1;
 688                 free(opts->strategy_opts);
 689                 opts->strategy_opts = xstrdup(buf.buf);
 690         }
 691
 692         strbuf_release(&buf);
 693
 694         return 0;
 695 }
 696
 697 static int rebase_write_basic_state(struct rebase_options *opts)
 698 {
 699         write_file(state_dir_path("head-name", opts), "%s",
 700                    opts->head_name ? opts->head_name : "detached HEAD");
 701         write_file(state_dir_path("onto", opts), "%s",
 702                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 703         write_file(state_dir_path("orig-head", opts), "%s",
 704                    oid_to_hex(&opts->orig_head));
 705         if (!(opts->flags & REBASE_NO_QUIET))
 706                 write_file(state_dir_path("quiet", opts), "%s", "");
 707         if (opts->flags & REBASE_VERBOSE)
 708                 write_file(state_dir_path("verbose", opts), "%s", "");
 709         if (opts->strategy)
 710                 write_file(state_dir_path("strategy", opts), "%s",
 711                            opts->strategy);
 712         if (opts->strategy_opts)
 713                 write_file(state_dir_path("strategy_opts", opts), "%s",
 714                            opts->strategy_opts);
 715         if (opts->allow_rerere_autoupdate > 0)
 716                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 717                            "-%s-rerere-autoupdate",
 718                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 719                                 "" : "-no");
 720         if (opts->gpg_sign_opt)
 721                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 722                            opts->gpg_sign_opt);
 723         if (opts->signoff)
 724                 write_file(state_dir_path("signoff", opts), "--signoff");
 725
 726         return 0;
 727 }
 728
 729 static int apply_autostash(struct rebase_options *opts)
 730 {
 731         const char *path = state_dir_path("autostash", opts);
 732         struct strbuf autostash = STRBUF_INIT;
 733         struct child_process stash_apply = CHILD_PROCESS_INIT;
 734
 735         if (!file_exists(path))
 736                 return 0;
 737
 738         if (read_one(path, &autostash))
 739                 return error(_("Could not read '%s'"), path);
 740         /* Ensure that the hash is not mistaken for a number */
 741         strbuf_addstr(&autostash, "^0");
 742         argv_array_pushl(&stash_apply.args,
 743                          "stash", "apply", autostash.buf, NULL);
 744         stash_apply.git_cmd = 1;
 745         stash_apply.no_stderr = stash_apply.no_stdout =
 746                 stash_apply.no_stdin = 1;
 747         if (!run_command(&stash_apply))
 748                 printf(_("Applied autostash.\n"));
 749         else {
 750                 struct argv_array args = ARGV_ARRAY_INIT;
 751                 int res = 0;
 752
 753                 argv_array_pushl(&args,
 754                                  "stash", "store", "-m", "autostash", "-q",
 755                                  autostash.buf, NULL);
 756                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 757                         res = error(_("Cannot store %s"), autostash.buf);
 758                 argv_array_clear(&args);
 759                 strbuf_release(&autostash);
 760                 if (res)
 761                         return res;
 762
 763                 fprintf(stderr,
 764                         _("Applying autostash resulted in conflicts.\n"
 765                           "Your changes are safe in the stash.\n"
 766                           "You can run \"git stash pop\" or \"git stash drop\" "
 767                           "at any time.\n"));
 768         }
 769
 770         strbuf_release(&autostash);
 771         return 0;
 772 }
 773
 774 static int finish_rebase(struct rebase_options *opts)
 775 {
 776         struct strbuf dir = STRBUF_INIT;
 777         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 778         int ret = 0;
 779
 780         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 781         apply_autostash(opts);
 782         close_object_store(the_repository->objects);
 783         /*
 784          * We ignore errors in 'gc --auto', since the
 785          * user should see them.
 786          */
 787         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 788         if (opts->type == REBASE_INTERACTIVE) {
 789                 struct replay_opts replay = REPLAY_OPTS_INIT;
 790
 791                 replay.action = REPLAY_INTERACTIVE_REBASE;
 792                 ret = sequencer_remove_state(&replay);
 793         } else {
 794                 strbuf_addstr(&dir, opts->state_dir);
 795                 if (remove_dir_recursively(&dir, 0))
 796                         ret = error(_("could not remove '%s'"),
 797                                     opts->state_dir);
 798                 strbuf_release(&dir);
 799         }
 800
 801         return ret;
 802 }
 803
 804 static struct commit *peel_committish(const char *name)
 805 {
 806         struct object *obj;
 807         struct object_id oid;
 808
 809         if (get_oid(name, &oid))
 810                 return NULL;
 811         obj = parse_object(the_repository, &oid);
 812         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 813 }
 814
 815 static void add_var(struct strbuf *buf, const char *name, const char *value)
 816 {
 817         if (!value)
 818                 strbuf_addf(buf, "unset %s; ", name);
 819         else {
 820                 strbuf_addf(buf, "%s=", name);
 821                 sq_quote_buf(buf, value);
 822                 strbuf_addstr(buf, "; ");
 823         }
 824 }
 825
 826 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 827
 828 #define RESET_HEAD_DETACH (1<<0)
 829 #define RESET_HEAD_HARD (1<<1)
 830 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 831 #define RESET_HEAD_REFS_ONLY (1<<3)
 832 #define RESET_ORIG_HEAD (1<<4)
 833
 834 static int reset_head(struct object_id *oid, const char *action,
 835                       const char *switch_to_branch, unsigned flags,
 836                       const char *reflog_orig_head, const char *reflog_head)
 837 {
 838         unsigned detach_head = flags & RESET_HEAD_DETACH;
 839         unsigned reset_hard = flags & RESET_HEAD_HARD;
 840         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 841         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 842         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 843         struct object_id head_oid;
 844         struct tree_desc desc[2] = { { NULL }, { NULL } };
 845         struct lock_file lock = LOCK_INIT;
 846         struct unpack_trees_options unpack_tree_opts;
 847         struct tree *tree;
 848         const char *reflog_action;
 849         struct strbuf msg = STRBUF_INIT;
 850         size_t prefix_len;
 851         struct object_id *orig = NULL, oid_orig,
 852                 *old_orig = NULL, oid_old_orig;
 853         int ret = 0, nr = 0;
 854
 855         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 856                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 857
 858         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 859                 ret = -1;
 860                 goto leave_reset_head;
 861         }
 862
 863         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 864                 ret = error(_("could not determine HEAD revision"));
 865                 goto leave_reset_head;
 866         }
 867
 868         if (!oid)
 869                 oid = &head_oid;
 870
 871         if (refs_only)
 872                 goto reset_head_refs;
 873
 874         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 875         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 876         unpack_tree_opts.head_idx = 1;
 877         unpack_tree_opts.src_index = the_repository->index;
 878         unpack_tree_opts.dst_index = the_repository->index;
 879         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 880         unpack_tree_opts.update = 1;
 881         unpack_tree_opts.merge = 1;
 882         if (!detach_head)
 883                 unpack_tree_opts.reset = 1;
 884
 885         if (repo_read_index_unmerged(the_repository) < 0) {
 886                 ret = error(_("could not read index"));
 887                 goto leave_reset_head;
 888         }
 889
 890         if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 891                 ret = error(_("failed to find tree of %s"),
 892                             oid_to_hex(&head_oid));
 893                 goto leave_reset_head;
 894         }
 895
 896         if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 897                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 898                 goto leave_reset_head;
 899         }
 900
 901         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 902                 ret = -1;
 903                 goto leave_reset_head;
 904         }
 905
 906         tree = parse_tree_indirect(oid);
 907         prime_cache_tree(the_repository, the_repository->index, tree);
 908
 909         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 910                 ret = error(_("could not write index"));
 911                 goto leave_reset_head;
 912         }
 913
 914 reset_head_refs:
 915         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 916         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 917         prefix_len = msg.len;
 918
 919         if (update_orig_head) {
 920                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 921                         old_orig = &oid_old_orig;
 922                 if (!get_oid("HEAD", &oid_orig)) {
 923                         orig = &oid_orig;
 924                         if (!reflog_orig_head) {
 925                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 926                                 reflog_orig_head = msg.buf;
 927                         }
 928                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 929                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 930                 } else if (old_orig)
 931                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 932         }
 933
 934         if (!reflog_head) {
 935                 strbuf_setlen(&msg, prefix_len);
 936                 strbuf_addstr(&msg, "updating HEAD");
 937                 reflog_head = msg.buf;
 938         }
 939         if (!switch_to_branch)
 940                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 941                                  detach_head ? REF_NO_DEREF : 0,
 942                                  UPDATE_REFS_MSG_ON_ERR);
 943         else {
 944                 ret = update_ref(reflog_head, switch_to_branch, oid,
 945                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 946                 if (!ret)
 947                         ret = create_symref("HEAD", switch_to_branch,
 948                                             reflog_head);
 949         }
 950         if (run_hook)
 951                 run_hook_le(NULL, "post-checkout",
 952                             oid_to_hex(orig ? orig : &null_oid),
 953                             oid_to_hex(oid), "1", NULL);
 954
 955 leave_reset_head:
 956         strbuf_release(&msg);
 957         rollback_lock_file(&lock);
 958         while (nr)
 959                 free((void *)desc[--nr].buffer);
 960         return ret;
 961 }
 962
 963 static int move_to_original_branch(struct rebase_options *opts)
 964 {
 965         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 966         int ret;
 967
 968         if (!opts->head_name)
 969                 return 0; /* nothing to move back to */
 970
 971         if (!opts->onto)
 972                 BUG("move_to_original_branch without onto");
 973
 974         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 975                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 976         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 977                     opts->head_name);
 978         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 979                          orig_head_reflog.buf, head_reflog.buf);
 980
 981         strbuf_release(&orig_head_reflog);
 982         strbuf_release(&head_reflog);
 983         return ret;
 984 }
 985
 986 static const char *resolvemsg =
 987 N_("Resolve all conflicts manually, mark them as resolved with\n"
 988 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 989 "You can instead skip this commit: run \"git rebase --skip\".\n"
 990 "To abort and get back to the state before \"git rebase\", run "
 991 "\"git rebase --abort\".");
 992
 993 static int run_am(struct rebase_options *opts)
 994 {
 995         struct child_process am = CHILD_PROCESS_INIT;
 996         struct child_process format_patch = CHILD_PROCESS_INIT;
 997         struct strbuf revisions = STRBUF_INIT;
 998         int status;
 999         char *rebased_patches;
1000
1001         am.git_cmd = 1;
1002         argv_array_push(&am.args, "am");
1003
1004         if (opts->action && !strcmp("continue", opts->action)) {
1005                 argv_array_push(&am.args, "--resolved");
1006                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1007                 if (opts->gpg_sign_opt)
1008                         argv_array_push(&am.args, opts->gpg_sign_opt);
1009                 status = run_command(&am);
1010                 if (status)
1011                         return status;
1012
1013                 return move_to_original_branch(opts);
1014         }
1015         if (opts->action && !strcmp("skip", opts->action)) {
1016                 argv_array_push(&am.args, "--skip");
1017                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1018                 status = run_command(&am);
1019                 if (status)
1020                         return status;
1021
1022                 return move_to_original_branch(opts);
1023         }
1024         if (opts->action && !strcmp("show-current-patch", opts->action)) {
1025                 argv_array_push(&am.args, "--show-current-patch");
1026                 return run_command(&am);
1027         }
1028
1029         strbuf_addf(&revisions, "%s...%s",
1030                     oid_to_hex(opts->root ?
1031                                /* this is now equivalent to !opts->upstream */
1032                                &opts->onto->object.oid :
1033                                &opts->upstream->object.oid),
1034                     oid_to_hex(&opts->orig_head));
1035
1036         rebased_patches = xstrdup(git_path("rebased-patches"));
1037         format_patch.out = open(rebased_patches,
1038                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1039         if (format_patch.out < 0) {
1040                 status = error_errno(_("could not open '%s' for writing"),
1041                                      rebased_patches);
1042                 free(rebased_patches);
1043                 argv_array_clear(&am.args);
1044                 return status;
1045         }
1046
1047         format_patch.git_cmd = 1;
1048         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1049                          "--full-index", "--cherry-pick", "--right-only",
1050                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1051                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
1052                          "--no-base", NULL);
1053         if (opts->git_format_patch_opt.len)
1054                 argv_array_split(&format_patch.args,
1055                                  opts->git_format_patch_opt.buf);
1056         argv_array_push(&format_patch.args, revisions.buf);
1057         if (opts->restrict_revision)
1058                 argv_array_pushf(&format_patch.args, "^%s",
1059                                  oid_to_hex(&opts->restrict_revision->object.oid));
1060
1061         status = run_command(&format_patch);
1062         if (status) {
1063                 unlink(rebased_patches);
1064                 free(rebased_patches);
1065                 argv_array_clear(&am.args);
1066
1067                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1068                            "HEAD", NULL);
1069                 error(_("\ngit encountered an error while preparing the "
1070                         "patches to replay\n"
1071                         "these revisions:\n"
1072                         "\n    %s\n\n"
1073                         "As a result, git cannot rebase them."),
1074                       opts->revisions);
1075
1076                 strbuf_release(&revisions);
1077                 return status;
1078         }
1079         strbuf_release(&revisions);
1080
1081         am.in = open(rebased_patches, O_RDONLY);
1082         if (am.in < 0) {
1083                 status = error_errno(_("could not open '%s' for reading"),
1084                                      rebased_patches);
1085                 free(rebased_patches);
1086                 argv_array_clear(&am.args);
1087                 return status;
1088         }
1089
1090         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1091         argv_array_push(&am.args, "--rebasing");
1092         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1093         argv_array_push(&am.args, "--patch-format=mboxrd");
1094         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1095                 argv_array_push(&am.args, "--rerere-autoupdate");
1096         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1097                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1098         if (opts->gpg_sign_opt)
1099                 argv_array_push(&am.args, opts->gpg_sign_opt);
1100         status = run_command(&am);
1101         unlink(rebased_patches);
1102         free(rebased_patches);
1103
1104         if (!status) {
1105                 return move_to_original_branch(opts);
1106         }
1107
1108         if (is_directory(opts->state_dir))
1109                 rebase_write_basic_state(opts);
1110
1111         return status;
1112 }
1113
1114 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1115 {
1116         const char *argv[] = { NULL, NULL };
1117         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1118         int status;
1119         const char *backend, *backend_func;
1120
1121         if (opts->type == REBASE_INTERACTIVE) {
1122                 /* Run builtin interactive rebase */
1123                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1124                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1125                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1126                         opts->autosquash = 0;
1127                 }
1128                 if (opts->gpg_sign_opt) {
1129                         /* remove the leading "-S" */
1130                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1131                         free(opts->gpg_sign_opt);
1132                         opts->gpg_sign_opt = tmp;
1133                 }
1134
1135                 status = run_rebase_interactive(opts, action);
1136                 goto finished_rebase;
1137         }
1138
1139         if (opts->type == REBASE_AM) {
1140                 status = run_am(opts);
1141                 goto finished_rebase;
1142         }
1143
1144         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1145         add_var(&script_snippet, "state_dir", opts->state_dir);
1146
1147         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1148         add_var(&script_snippet, "upstream", opts->upstream ?
1149                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1150         add_var(&script_snippet, "head_name",
1151                 opts->head_name ? opts->head_name : "detached HEAD");
1152         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1153         add_var(&script_snippet, "onto", opts->onto ?
1154                 oid_to_hex(&opts->onto->object.oid) : NULL);
1155         add_var(&script_snippet, "onto_name", opts->onto_name);
1156         add_var(&script_snippet, "revisions", opts->revisions);
1157         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1158                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1159         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1160         add_var(&script_snippet, "git_am_opt", buf.buf);
1161         strbuf_release(&buf);
1162         add_var(&script_snippet, "verbose",
1163                 opts->flags & REBASE_VERBOSE ? "t" : "");
1164         add_var(&script_snippet, "diffstat",
1165                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1166         add_var(&script_snippet, "force_rebase",
1167                 opts->flags & REBASE_FORCE ? "t" : "");
1168         if (opts->switch_to)
1169                 add_var(&script_snippet, "switch_to", opts->switch_to);
1170         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1171         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1172         add_var(&script_snippet, "allow_rerere_autoupdate",
1173                 opts->allow_rerere_autoupdate ?
1174                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1175                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1176         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1177         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1178         add_var(&script_snippet, "cmd", opts->cmd);
1179         add_var(&script_snippet, "allow_empty_message",
1180                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1181         add_var(&script_snippet, "rebase_merges",
1182                 opts->rebase_merges ? "t" : "");
1183         add_var(&script_snippet, "rebase_cousins",
1184                 opts->rebase_cousins ? "t" : "");
1185         add_var(&script_snippet, "strategy", opts->strategy);
1186         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1187         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1188         add_var(&script_snippet, "squash_onto",
1189                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1190         add_var(&script_snippet, "git_format_patch_opt",
1191                 opts->git_format_patch_opt.buf);
1192
1193         if (is_interactive(opts) &&
1194             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1195                 strbuf_addstr(&script_snippet,
1196                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1197                 opts->autosquash = 0;
1198         }
1199
1200         switch (opts->type) {
1201         case REBASE_PRESERVE_MERGES:
1202                 backend = "git-rebase--preserve-merges";
1203                 backend_func = "git_rebase__preserve_merges";
1204                 break;
1205         default:
1206                 BUG("Unhandled rebase type %d", opts->type);
1207                 break;
1208         }
1209
1210         strbuf_addf(&script_snippet,
1211                     ". git-sh-setup && . %s && %s", backend, backend_func);
1212         argv[0] = script_snippet.buf;
1213
1214         status = run_command_v_opt(argv, RUN_USING_SHELL);
1215 finished_rebase:
1216         if (opts->dont_finish_rebase)
1217                 ; /* do nothing */
1218         else if (opts->type == REBASE_INTERACTIVE)
1219                 ; /* interactive rebase cleans up after itself */
1220         else if (status == 0) {
1221                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1222                         finish_rebase(opts);
1223         } else if (status == 2) {
1224                 struct strbuf dir = STRBUF_INIT;
1225
1226                 apply_autostash(opts);
1227                 strbuf_addstr(&dir, opts->state_dir);
1228                 remove_dir_recursively(&dir, 0);
1229                 strbuf_release(&dir);
1230                 die("Nothing to do");
1231         }
1232
1233         strbuf_release(&script_snippet);
1234
1235         return status ? -1 : 0;
1236 }
1237
1238 static int rebase_config(const char *var, const char *value, void *data)
1239 {
1240         struct rebase_options *opts = data;
1241
1242         if (!strcmp(var, "rebase.stat")) {
1243                 if (git_config_bool(var, value))
1244                         opts->flags |= REBASE_DIFFSTAT;
1245                 else
1246                         opts->flags &= ~REBASE_DIFFSTAT;
1247                 return 0;
1248         }
1249
1250         if (!strcmp(var, "rebase.autosquash")) {
1251                 opts->autosquash = git_config_bool(var, value);
1252                 return 0;
1253         }
1254
1255         if (!strcmp(var, "commit.gpgsign")) {
1256                 free(opts->gpg_sign_opt);
1257                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1258                         xstrdup("-S") : NULL;
1259                 return 0;
1260         }
1261
1262         if (!strcmp(var, "rebase.autostash")) {
1263                 opts->autostash = git_config_bool(var, value);
1264                 return 0;
1265         }
1266
1267         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1268                 opts->reschedule_failed_exec = git_config_bool(var, value);
1269                 return 0;
1270         }
1271
1272         if (!strcmp(var, "rebase.usebuiltin")) {
1273                 opts->use_legacy_rebase = !git_config_bool(var, value);
1274                 return 0;
1275         }
1276
1277         if (!strcmp(var, "rebase.backend")) {
1278                 return git_config_string(&opts->default_backend, var, value);
1279         }
1280
1281         return git_default_config(var, value, data);
1282 }
1283
1284 /*
1285  * Determines whether the commits in from..to are linear, i.e. contain
1286  * no merge commits. This function *expects* `from` to be an ancestor of
1287  * `to`.
1288  */
1289 static int is_linear_history(struct commit *from, struct commit *to)
1290 {
1291         while (to && to != from) {
1292                 parse_commit(to);
1293                 if (!to->parents)
1294                         return 1;
1295                 if (to->parents->next)
1296                         return 0;
1297                 to = to->parents->item;
1298         }
1299         return 1;
1300 }
1301
1302 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1303                             struct commit *restrict_revision,
1304                             struct object_id *head_oid, struct object_id *merge_base)
1305 {
1306         struct commit *head = lookup_commit(the_repository, head_oid);
1307         struct commit_list *merge_bases = NULL;
1308         int res = 0;
1309
1310         if (!head)
1311                 goto done;
1312
1313         merge_bases = get_merge_bases(onto, head);
1314         if (!merge_bases || merge_bases->next) {
1315                 oidcpy(merge_base, &null_oid);
1316                 goto done;
1317         }
1318
1319         oidcpy(merge_base, &merge_bases->item->object.oid);
1320         if (!oideq(merge_base, &onto->object.oid))
1321                 goto done;
1322
1323         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1324                 goto done;
1325
1326         if (!upstream)
1327                 goto done;
1328
1329         free_commit_list(merge_bases);
1330         merge_bases = get_merge_bases(upstream, head);
1331         if (!merge_bases || merge_bases->next)
1332                 goto done;
1333
1334         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1335                 goto done;
1336
1337         res = 1;
1338
1339 done:
1340         free_commit_list(merge_bases);
1341         return res && is_linear_history(onto, head);
1342 }
1343
1344 static int parse_opt_am(const struct option *opt, const char *arg, int unset)
1345 {
1346         struct rebase_options *opts = opt->value;
1347
1348         BUG_ON_OPT_NEG(unset);
1349         BUG_ON_OPT_ARG(arg);
1350
1351         opts->type = REBASE_AM;
1352
1353         return 0;
1354 }
1355
1356 /* -i followed by -m is still -i */
1357 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1358 {
1359         struct rebase_options *opts = opt->value;
1360
1361         BUG_ON_OPT_NEG(unset);
1362         BUG_ON_OPT_ARG(arg);
1363
1364         if (!is_interactive(opts))
1365                 opts->type = REBASE_MERGE;
1366
1367         return 0;
1368 }
1369
1370 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1371 static int parse_opt_interactive(const struct option *opt, const char *arg,
1372                                  int unset)
1373 {
1374         struct rebase_options *opts = opt->value;
1375
1376         BUG_ON_OPT_NEG(unset);
1377         BUG_ON_OPT_ARG(arg);
1378
1379         opts->type = REBASE_INTERACTIVE;
1380         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1381
1382         return 0;
1383 }
1384
1385 static enum empty_type parse_empty_value(const char *value)
1386 {
1387         if (!strcasecmp(value, "drop"))
1388                 return EMPTY_DROP;
1389         else if (!strcasecmp(value, "keep"))
1390                 return EMPTY_KEEP;
1391         else if (!strcasecmp(value, "ask"))
1392                 return EMPTY_ASK;
1393
1394         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
1395 }
1396
1397 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
1398 {
1399         struct rebase_options *options = opt->value;
1400         enum empty_type value = parse_empty_value(arg);
1401
1402         BUG_ON_OPT_NEG(unset);
1403
1404         options->empty = value;
1405         return 0;
1406 }
1407
1408 static void NORETURN error_on_missing_default_upstream(void)
1409 {
1410         struct branch *current_branch = branch_get(NULL);
1411
1412         printf(_("%s\n"
1413                  "Please specify which branch you want to rebase against.\n"
1414                  "See git-rebase(1) for details.\n"
1415                  "\n"
1416                  "    git rebase '<branch>'\n"
1417                  "\n"),
1418                 current_branch ? _("There is no tracking information for "
1419                         "the current branch.") :
1420                         _("You are not currently on a branch."));
1421
1422         if (current_branch) {
1423                 const char *remote = current_branch->remote_name;
1424
1425                 if (!remote)
1426                         remote = _("<remote>");
1427
1428                 printf(_("If you wish to set tracking information for this "
1429                          "branch you can do so with:\n"
1430                          "\n"
1431                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1432                          "\n"),
1433                        remote, current_branch->name);
1434         }
1435         exit(1);
1436 }
1437
1438 static void set_reflog_action(struct rebase_options *options)
1439 {
1440         const char *env;
1441         struct strbuf buf = STRBUF_INIT;
1442
1443         if (!is_interactive(options))
1444                 return;
1445
1446         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1447         if (env && strcmp("rebase", env))
1448                 return; /* only override it if it is "rebase" */
1449
1450         strbuf_addf(&buf, "rebase (%s)", options->action);
1451         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1452         strbuf_release(&buf);
1453 }
1454
1455 static int check_exec_cmd(const char *cmd)
1456 {
1457         if (strchr(cmd, '\n'))
1458                 return error(_("exec commands cannot contain newlines"));
1459
1460         /* Does the command consist purely of whitespace? */
1461         if (!cmd[strspn(cmd, " \t\r\f\v")])
1462                 return error(_("empty exec command"));
1463
1464         return 0;
1465 }
1466
1467
1468 int cmd_rebase(int argc, const char **argv, const char *prefix)
1469 {
1470         struct rebase_options options = REBASE_OPTIONS_INIT;
1471         const char *branch_name;
1472         int ret, flags, total_argc, in_progress = 0;
1473         int keep_base = 0;
1474         int ok_to_skip_pre_rebase = 0;
1475         struct strbuf msg = STRBUF_INIT;
1476         struct strbuf revisions = STRBUF_INIT;
1477         struct strbuf buf = STRBUF_INIT;
1478         struct object_id merge_base;
1479         enum action action = ACTION_NONE;
1480         const char *gpg_sign = NULL;
1481         struct string_list exec = STRING_LIST_INIT_NODUP;
1482         const char *rebase_merges = NULL;
1483         int fork_point = -1;
1484         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1485         struct object_id squash_onto;
1486         char *squash_onto_name = NULL;
1487         int reschedule_failed_exec = -1;
1488         int allow_preemptive_ff = 1;
1489         struct option builtin_rebase_options[] = {
1490                 OPT_STRING(0, "onto", &options.onto_name,
1491                            N_("revision"),
1492                            N_("rebase onto given branch instead of upstream")),
1493                 OPT_BOOL(0, "keep-base", &keep_base,
1494                          N_("use the merge-base of upstream and branch as the current base")),
1495                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1496                          N_("allow pre-rebase hook to run")),
1497                 OPT_NEGBIT('q', "quiet", &options.flags,
1498                            N_("be quiet. implies --no-stat"),
1499                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1500                 OPT_BIT('v', "verbose", &options.flags,
1501                         N_("display a diffstat of what changed upstream"),
1502                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1503                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1504                         N_("do not show diffstat of what changed upstream"),
1505                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1506                 OPT_BOOL(0, "signoff", &options.signoff,
1507                          N_("add a Signed-off-by: line to each commit")),
1508                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1509                                   NULL, N_("passed to 'git am'"),
1510                                   PARSE_OPT_NOARG),
1511                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1512                                   &options.git_am_opts, NULL,
1513                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1514                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1515                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1516                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1517                                   N_("passed to 'git apply'"), 0),
1518                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1519                                   N_("action"), N_("passed to 'git apply'"), 0),
1520                 OPT_BIT('f', "force-rebase", &options.flags,
1521                         N_("cherry-pick all commits, even if unchanged"),
1522                         REBASE_FORCE),
1523                 OPT_BIT(0, "no-ff", &options.flags,
1524                         N_("cherry-pick all commits, even if unchanged"),
1525                         REBASE_FORCE),
1526                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1527                             ACTION_CONTINUE),
1528                 OPT_CMDMODE(0, "skip", &action,
1529                             N_("skip current patch and continue"), ACTION_SKIP),
1530                 OPT_CMDMODE(0, "abort", &action,
1531                             N_("abort and check out the original branch"),
1532                             ACTION_ABORT),
1533                 OPT_CMDMODE(0, "quit", &action,
1534                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1535                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1536                             "during an interactive rebase"), ACTION_EDIT_TODO),
1537                 OPT_CMDMODE(0, "show-current-patch", &action,
1538                             N_("show the patch file being applied or merged"),
1539                             ACTION_SHOW_CURRENT_PATCH),
1540                 { OPTION_CALLBACK, 0, "am", &options, NULL,
1541                         N_("use apply-mail strategies to rebase"),
1542                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1543                         parse_opt_am },
1544                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1545                         N_("use merging strategies to rebase"),
1546                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1547                         parse_opt_merge },
1548                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1549                         N_("let the user edit the list of commits to rebase"),
1550                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1551                         parse_opt_interactive },
1552                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1553                               N_("(DEPRECATED) try to recreate merges instead of "
1554                                  "ignoring them"),
1555                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1556                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1557                 OPT_CALLBACK_F(0, "empty", &options, N_("{drop,keep,ask}"),
1558                                N_("how to handle commits that become empty"),
1559                                PARSE_OPT_NONEG, parse_opt_empty),
1560                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
1561                         N_("(DEPRECATED) keep empty commits"),
1562                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1563                         parse_opt_keep_empty },
1564                 OPT_BOOL(0, "autosquash", &options.autosquash,
1565                          N_("move commits that begin with "
1566                             "squash!/fixup! under -i")),
1567                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1568                         N_("GPG-sign commits"),
1569                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1570                 OPT_BOOL(0, "autostash", &options.autostash,
1571                          N_("automatically stash/stash pop before and after")),
1572                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1573                                 N_("add exec lines after each commit of the "
1574                                    "editable list")),
1575                 OPT_BOOL_F(0, "allow-empty-message",
1576                            &options.allow_empty_message,
1577                            N_("allow rebasing commits with empty messages"),
1578                            PARSE_OPT_HIDDEN),
1579                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1580                         N_("mode"),
1581                         N_("try to rebase merges instead of skipping them"),
1582                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1583                 OPT_BOOL(0, "fork-point", &fork_point,
1584                          N_("use 'merge-base --fork-point' to refine upstream")),
1585                 OPT_STRING('s', "strategy", &options.strategy,
1586                            N_("strategy"), N_("use the given merge strategy")),
1587                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1588                                 N_("option"),
1589                                 N_("pass the argument through to the merge "
1590                                    "strategy")),
1591                 OPT_BOOL(0, "root", &options.root,
1592                          N_("rebase all reachable commits up to the root(s)")),
1593                 OPT_BOOL(0, "reschedule-failed-exec",
1594                          &reschedule_failed_exec,
1595                          N_("automatically re-schedule any `exec` that fails")),
1596                 OPT_END(),
1597         };
1598         int i;
1599
1600         if (argc == 2 && !strcmp(argv[1], "-h"))
1601                 usage_with_options(builtin_rebase_usage,
1602                                    builtin_rebase_options);
1603
1604         options.allow_empty_message = 1;
1605         git_config(rebase_config, &options);
1606
1607         if (options.use_legacy_rebase ||
1608             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1609                 warning(_("the rebase.useBuiltin support has been removed!\n"
1610                           "See its entry in 'git help config' for details."));
1611
1612         strbuf_reset(&buf);
1613         strbuf_addf(&buf, "%s/applying", apply_dir());
1614         if(file_exists(buf.buf))
1615                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1616
1617         if (is_directory(apply_dir())) {
1618                 options.type = REBASE_AM;
1619                 options.state_dir = apply_dir();
1620         } else if (is_directory(merge_dir())) {
1621                 strbuf_reset(&buf);
1622                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1623                 if (is_directory(buf.buf)) {
1624                         options.type = REBASE_PRESERVE_MERGES;
1625                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1626                 } else {
1627                         strbuf_reset(&buf);
1628                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1629                         if(file_exists(buf.buf)) {
1630                                 options.type = REBASE_INTERACTIVE;
1631                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1632                         } else
1633                                 options.type = REBASE_MERGE;
1634                 }
1635                 options.state_dir = merge_dir();
1636         }
1637
1638         if (options.type != REBASE_UNSPECIFIED)
1639                 in_progress = 1;
1640
1641         total_argc = argc;
1642         argc = parse_options(argc, argv, prefix,
1643                              builtin_rebase_options,
1644                              builtin_rebase_usage, 0);
1645
1646         if (action != ACTION_NONE && total_argc != 2) {
1647                 usage_with_options(builtin_rebase_usage,
1648                                    builtin_rebase_options);
1649         }
1650
1651         if (argc > 2)
1652                 usage_with_options(builtin_rebase_usage,
1653                                    builtin_rebase_options);
1654
1655         if (options.type == REBASE_PRESERVE_MERGES)
1656                 warning(_("git rebase --preserve-merges is deprecated. "
1657                           "Use --rebase-merges instead."));
1658
1659         if (keep_base) {
1660                 if (options.onto_name)
1661                         die(_("cannot combine '--keep-base' with '--onto'"));
1662                 if (options.root)
1663                         die(_("cannot combine '--keep-base' with '--root'"));
1664         }
1665
1666         if (action != ACTION_NONE && !in_progress)
1667                 die(_("No rebase in progress?"));
1668         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1669
1670         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1671                 die(_("The --edit-todo action can only be used during "
1672                       "interactive rebase."));
1673
1674         if (trace2_is_enabled()) {
1675                 if (is_interactive(&options))
1676                         trace2_cmd_mode("interactive");
1677                 else if (exec.nr)
1678                         trace2_cmd_mode("interactive-exec");
1679                 else
1680                         trace2_cmd_mode(action_names[action]);
1681         }
1682
1683         switch (action) {
1684         case ACTION_CONTINUE: {
1685                 struct object_id head;
1686                 struct lock_file lock_file = LOCK_INIT;
1687                 int fd;
1688
1689                 options.action = "continue";
1690                 set_reflog_action(&options);
1691
1692                 /* Sanity check */
1693                 if (get_oid("HEAD", &head))
1694                         die(_("Cannot read HEAD"));
1695
1696                 fd = hold_locked_index(&lock_file, 0);
1697                 if (repo_read_index(the_repository) < 0)
1698                         die(_("could not read index"));
1699                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1700                               NULL);
1701                 if (0 <= fd)
1702                         repo_update_index_if_able(the_repository, &lock_file);
1703                 rollback_lock_file(&lock_file);
1704
1705                 if (has_unstaged_changes(the_repository, 1)) {
1706                         puts(_("You must edit all merge conflicts and then\n"
1707                                "mark them as resolved using git add"));
1708                         exit(1);
1709                 }
1710                 if (read_basic_state(&options))
1711                         exit(1);
1712                 goto run_rebase;
1713         }
1714         case ACTION_SKIP: {
1715                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1716
1717                 options.action = "skip";
1718                 set_reflog_action(&options);
1719
1720                 rerere_clear(the_repository, &merge_rr);
1721                 string_list_clear(&merge_rr, 1);
1722
1723                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1724                                NULL, NULL) < 0)
1725                         die(_("could not discard worktree changes"));
1726                 remove_branch_state(the_repository, 0);
1727                 if (read_basic_state(&options))
1728                         exit(1);
1729                 goto run_rebase;
1730         }
1731         case ACTION_ABORT: {
1732                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1733                 options.action = "abort";
1734                 set_reflog_action(&options);
1735
1736                 rerere_clear(the_repository, &merge_rr);
1737                 string_list_clear(&merge_rr, 1);
1738
1739                 if (read_basic_state(&options))
1740                         exit(1);
1741                 if (reset_head(&options.orig_head, "reset",
1742                                options.head_name, RESET_HEAD_HARD,
1743                                NULL, NULL) < 0)
1744                         die(_("could not move back to %s"),
1745                             oid_to_hex(&options.orig_head));
1746                 remove_branch_state(the_repository, 0);
1747                 ret = !!finish_rebase(&options);
1748                 goto cleanup;
1749         }
1750         case ACTION_QUIT: {
1751                 if (options.type == REBASE_INTERACTIVE) {
1752                         struct replay_opts replay = REPLAY_OPTS_INIT;
1753
1754                         replay.action = REPLAY_INTERACTIVE_REBASE;
1755                         ret = !!sequencer_remove_state(&replay);
1756                 } else {
1757                         strbuf_reset(&buf);
1758                         strbuf_addstr(&buf, options.state_dir);
1759                         ret = !!remove_dir_recursively(&buf, 0);
1760                         if (ret)
1761                                 error(_("could not remove '%s'"),
1762                                        options.state_dir);
1763                 }
1764                 goto cleanup;
1765         }
1766         case ACTION_EDIT_TODO:
1767                 options.action = "edit-todo";
1768                 options.dont_finish_rebase = 1;
1769                 goto run_rebase;
1770         case ACTION_SHOW_CURRENT_PATCH:
1771                 options.action = "show-current-patch";
1772                 options.dont_finish_rebase = 1;
1773                 goto run_rebase;
1774         case ACTION_NONE:
1775                 break;
1776         default:
1777                 BUG("action: %d", action);
1778         }
1779
1780         /* Make sure no rebase is in progress */
1781         if (in_progress) {
1782                 const char *last_slash = strrchr(options.state_dir, '/');
1783                 const char *state_dir_base =
1784                         last_slash ? last_slash + 1 : options.state_dir;
1785                 const char *cmd_live_rebase =
1786                         "git rebase (--continue | --abort | --skip)";
1787                 strbuf_reset(&buf);
1788                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1789                 die(_("It seems that there is already a %s directory, and\n"
1790                       "I wonder if you are in the middle of another rebase.  "
1791                       "If that is the\n"
1792                       "case, please try\n\t%s\n"
1793                       "If that is not the case, please\n\t%s\n"
1794                       "and run me again.  I am stopping in case you still "
1795                       "have something\n"
1796                       "valuable there.\n"),
1797                     state_dir_base, cmd_live_rebase, buf.buf);
1798         }
1799
1800         if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
1801             (action != ACTION_NONE) ||
1802             (exec.nr > 0) ||
1803             options.autosquash) {
1804                 allow_preemptive_ff = 0;
1805         }
1806
1807         for (i = 0; i < options.git_am_opts.argc; i++) {
1808                 const char *option = options.git_am_opts.argv[i], *p;
1809                 if (!strcmp(option, "--committer-date-is-author-date") ||
1810                     !strcmp(option, "--ignore-date") ||
1811                     !strcmp(option, "--whitespace=fix") ||
1812                     !strcmp(option, "--whitespace=strip"))
1813                         allow_preemptive_ff = 0;
1814                 else if (skip_prefix(option, "-C", &p)) {
1815                         while (*p)
1816                                 if (!isdigit(*(p++)))
1817                                         die(_("switch `C' expects a "
1818                                               "numerical value"));
1819                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1820                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1821                             strcmp(p, "error") && strcmp(p, "error-all"))
1822                                 die("Invalid whitespace option: '%s'", p);
1823                 }
1824         }
1825
1826         for (i = 0; i < exec.nr; i++)
1827                 if (check_exec_cmd(exec.items[i].string))
1828                         exit(1);
1829
1830         if (!(options.flags & REBASE_NO_QUIET))
1831                 argv_array_push(&options.git_am_opts, "-q");
1832
1833         if (options.empty != EMPTY_UNSPECIFIED)
1834                 imply_interactive(&options, "--empty");
1835
1836         if (gpg_sign) {
1837                 free(options.gpg_sign_opt);
1838                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1839         }
1840
1841         if (exec.nr) {
1842                 int i;
1843
1844                 imply_interactive(&options, "--exec");
1845
1846                 strbuf_reset(&buf);
1847                 for (i = 0; i < exec.nr; i++)
1848                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1849                 options.cmd = xstrdup(buf.buf);
1850         }
1851
1852         if (rebase_merges) {
1853                 if (!*rebase_merges)
1854                         ; /* default mode; do nothing */
1855                 else if (!strcmp("rebase-cousins", rebase_merges))
1856                         options.rebase_cousins = 1;
1857                 else if (strcmp("no-rebase-cousins", rebase_merges))
1858                         die(_("Unknown mode: %s"), rebase_merges);
1859                 options.rebase_merges = 1;
1860                 imply_interactive(&options, "--rebase-merges");
1861         }
1862
1863         if (strategy_options.nr) {
1864                 int i;
1865
1866                 if (!options.strategy)
1867                         options.strategy = "recursive";
1868
1869                 strbuf_reset(&buf);
1870                 for (i = 0; i < strategy_options.nr; i++)
1871                         strbuf_addf(&buf, " --%s",
1872                                     strategy_options.items[i].string);
1873                 options.strategy_opts = xstrdup(buf.buf);
1874         }
1875
1876         if (options.strategy) {
1877                 options.strategy = xstrdup(options.strategy);
1878                 switch (options.type) {
1879                 case REBASE_AM:
1880                         die(_("--strategy requires --merge or --interactive"));
1881                 case REBASE_MERGE:
1882                 case REBASE_INTERACTIVE:
1883                 case REBASE_PRESERVE_MERGES:
1884                         /* compatible */
1885                         break;
1886                 case REBASE_UNSPECIFIED:
1887                         options.type = REBASE_MERGE;
1888                         break;
1889                 default:
1890                         BUG("unhandled rebase type (%d)", options.type);
1891                 }
1892         }
1893
1894         if (options.type == REBASE_MERGE)
1895                 imply_interactive(&options, "--merge");
1896
1897         if (options.root && !options.onto_name)
1898                 imply_interactive(&options, "--root without --onto");
1899
1900         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1901                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1902
1903         if (options.git_am_opts.argc || options.type == REBASE_AM) {
1904                 /* all am options except -q are compatible only with --am */
1905                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1906                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1907                                 break;
1908
1909                 if (i >= 0) {
1910                         if (is_interactive(&options))
1911                                 die(_("cannot combine am options with either "
1912                                       "interactive or merge options"));
1913                         else
1914                                 options.type = REBASE_AM;
1915                 }
1916         }
1917
1918         if (options.type == REBASE_UNSPECIFIED) {
1919                 if (!strcmp(options.default_backend, "merge"))
1920                         imply_interactive(&options, "--merge");
1921                 else if (!strcmp(options.default_backend, "am"))
1922                         options.type = REBASE_AM;
1923                 else
1924                         die(_("Unknown rebase backend: %s"),
1925                             options.default_backend);
1926         }
1927
1928         switch (options.type) {
1929         case REBASE_MERGE:
1930         case REBASE_INTERACTIVE:
1931         case REBASE_PRESERVE_MERGES:
1932                 options.state_dir = merge_dir();
1933                 break;
1934         case REBASE_AM:
1935                 options.state_dir = apply_dir();
1936                 break;
1937         default:
1938                 BUG("options.type was just set above; should be unreachable.");
1939         }
1940
1941         if (options.empty == EMPTY_UNSPECIFIED) {
1942                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1943                         options.empty = EMPTY_ASK;
1944                 else if (exec.nr > 0)
1945                         options.empty = EMPTY_KEEP;
1946                 else
1947                         options.empty = EMPTY_DROP;
1948         }
1949         if (reschedule_failed_exec > 0 && !is_interactive(&options))
1950                 die(_("--reschedule-failed-exec requires "
1951                       "--exec or --interactive"));
1952         if (reschedule_failed_exec >= 0)
1953                 options.reschedule_failed_exec = reschedule_failed_exec;
1954
1955         if (options.signoff) {
1956                 if (options.type == REBASE_PRESERVE_MERGES)
1957                         die("cannot combine '--signoff' with "
1958                             "'--preserve-merges'");
1959                 argv_array_push(&options.git_am_opts, "--signoff");
1960                 options.flags |= REBASE_FORCE;
1961         }
1962
1963         if (options.type == REBASE_PRESERVE_MERGES) {
1964                 /*
1965                  * Note: incompatibility with --signoff handled in signoff block above
1966                  * Note: incompatibility with --interactive is just a strong warning;
1967                  *       git-rebase.txt caveats with "unless you know what you are doing"
1968                  */
1969                 if (options.rebase_merges)
1970                         die(_("cannot combine '--preserve-merges' with "
1971                               "'--rebase-merges'"));
1972
1973                 if (options.reschedule_failed_exec)
1974                         die(_("error: cannot combine '--preserve-merges' with "
1975                               "'--reschedule-failed-exec'"));
1976         }
1977
1978         if (!options.root) {
1979                 if (argc < 1) {
1980                         struct branch *branch;
1981
1982                         branch = branch_get(NULL);
1983                         options.upstream_name = branch_get_upstream(branch,
1984                                                                     NULL);
1985                         if (!options.upstream_name)
1986                                 error_on_missing_default_upstream();
1987                         if (fork_point < 0)
1988                                 fork_point = 1;
1989                 } else {
1990                         options.upstream_name = argv[0];
1991                         argc--;
1992                         argv++;
1993                         if (!strcmp(options.upstream_name, "-"))
1994                                 options.upstream_name = "@{-1}";
1995                 }
1996                 options.upstream = peel_committish(options.upstream_name);
1997                 if (!options.upstream)
1998                         die(_("invalid upstream '%s'"), options.upstream_name);
1999                 options.upstream_arg = options.upstream_name;
2000         } else {
2001                 if (!options.onto_name) {
2002                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
2003                                         &squash_onto, NULL, NULL) < 0)
2004                                 die(_("Could not create new root commit"));
2005                         options.squash_onto = &squash_onto;
2006                         options.onto_name = squash_onto_name =
2007                                 xstrdup(oid_to_hex(&squash_onto));
2008                 } else
2009                         options.root_with_onto = 1;
2010
2011                 options.upstream_name = NULL;
2012                 options.upstream = NULL;
2013                 if (argc > 1)
2014                         usage_with_options(builtin_rebase_usage,
2015                                            builtin_rebase_options);
2016                 options.upstream_arg = "--root";
2017         }
2018
2019         /* Make sure the branch to rebase onto is valid. */
2020         if (keep_base) {
2021                 strbuf_reset(&buf);
2022                 strbuf_addstr(&buf, options.upstream_name);
2023                 strbuf_addstr(&buf, "...");
2024                 options.onto_name = xstrdup(buf.buf);
2025         } else if (!options.onto_name)
2026                 options.onto_name = options.upstream_name;
2027         if (strstr(options.onto_name, "...")) {
2028                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
2029                         if (keep_base)
2030                                 die(_("'%s': need exactly one merge base with branch"),
2031                                     options.upstream_name);
2032                         else
2033                                 die(_("'%s': need exactly one merge base"),
2034                                     options.onto_name);
2035                 }
2036                 options.onto = lookup_commit_or_die(&merge_base,
2037                                                     options.onto_name);
2038         } else {
2039                 options.onto = peel_committish(options.onto_name);
2040                 if (!options.onto)
2041                         die(_("Does not point to a valid commit '%s'"),
2042                                 options.onto_name);
2043         }
2044
2045         /*
2046          * If the branch to rebase is given, that is the branch we will rebase
2047          * branch_name -- branch/commit being rebased, or
2048          *                HEAD (already detached)
2049          * orig_head -- commit object name of tip of the branch before rebasing
2050          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
2051          */
2052         if (argc == 1) {
2053                 /* Is it "rebase other branchname" or "rebase other commit"? */
2054                 branch_name = argv[0];
2055                 options.switch_to = argv[0];
2056
2057                 /* Is it a local branch? */
2058                 strbuf_reset(&buf);
2059                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
2060                 if (!read_ref(buf.buf, &options.orig_head))
2061                         options.head_name = xstrdup(buf.buf);
2062                 /* If not is it a valid ref (branch or commit)? */
2063                 else if (!get_oid(branch_name, &options.orig_head))
2064                         options.head_name = NULL;
2065                 else
2066                         die(_("fatal: no such branch/commit '%s'"),
2067                             branch_name);
2068         } else if (argc == 0) {
2069                 /* Do not need to switch branches, we are already on it. */
2070                 options.head_name =
2071                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
2072                                          &flags));
2073                 if (!options.head_name)
2074                         die(_("No such ref: %s"), "HEAD");
2075                 if (flags & REF_ISSYMREF) {
2076                         if (!skip_prefix(options.head_name,
2077                                          "refs/heads/", &branch_name))
2078                                 branch_name = options.head_name;
2079
2080                 } else {
2081                         FREE_AND_NULL(options.head_name);
2082                         branch_name = "HEAD";
2083                 }
2084                 if (get_oid("HEAD", &options.orig_head))
2085                         die(_("Could not resolve HEAD to a revision"));
2086         } else
2087                 BUG("unexpected number of arguments left to parse");
2088
2089         if (fork_point > 0) {
2090                 struct commit *head =
2091                         lookup_commit_reference(the_repository,
2092                                                 &options.orig_head);
2093                 options.restrict_revision =
2094                         get_fork_point(options.upstream_name, head);
2095         }
2096
2097         if (repo_read_index(the_repository) < 0)
2098                 die(_("could not read index"));
2099
2100         if (options.autostash) {
2101                 struct lock_file lock_file = LOCK_INIT;
2102                 int fd;
2103
2104                 fd = hold_locked_index(&lock_file, 0);
2105                 refresh_cache(REFRESH_QUIET);
2106                 if (0 <= fd)
2107                         repo_update_index_if_able(the_repository, &lock_file);
2108                 rollback_lock_file(&lock_file);
2109
2110                 if (has_unstaged_changes(the_repository, 1) ||
2111                     has_uncommitted_changes(the_repository, 1)) {
2112                         const char *autostash =
2113                                 state_dir_path("autostash", &options);
2114                         struct child_process stash = CHILD_PROCESS_INIT;
2115                         struct object_id oid;
2116
2117                         argv_array_pushl(&stash.args,
2118                                          "stash", "create", "autostash", NULL);
2119                         stash.git_cmd = 1;
2120                         stash.no_stdin = 1;
2121                         strbuf_reset(&buf);
2122                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
2123                                 die(_("Cannot autostash"));
2124                         strbuf_trim_trailing_newline(&buf);
2125                         if (get_oid(buf.buf, &oid))
2126                                 die(_("Unexpected stash response: '%s'"),
2127                                     buf.buf);
2128                         strbuf_reset(&buf);
2129                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
2130
2131                         if (safe_create_leading_directories_const(autostash))
2132                                 die(_("Could not create directory for '%s'"),
2133                                     options.state_dir);
2134                         write_file(autostash, "%s", oid_to_hex(&oid));
2135                         printf(_("Created autostash: %s\n"), buf.buf);
2136                         if (reset_head(NULL, "reset --hard",
2137                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2138                                 die(_("could not reset --hard"));
2139
2140                         if (discard_index(the_repository->index) < 0 ||
2141                                 repo_read_index(the_repository) < 0)
2142                                 die(_("could not read index"));
2143                 }
2144         }
2145
2146         if (require_clean_work_tree(the_repository, "rebase",
2147                                     _("Please commit or stash them."), 1, 1)) {
2148                 ret = 1;
2149                 goto cleanup;
2150         }
2151
2152         /*
2153          * Now we are rebasing commits upstream..orig_head (or with --root,
2154          * everything leading up to orig_head) on top of onto.
2155          */
2156
2157         /*
2158          * Check if we are already based on onto with linear history,
2159          * in which case we could fast-forward without replacing the commits
2160          * with new commits recreated by replaying their changes.
2161          *
2162          * Note that can_fast_forward() initializes merge_base, so we have to
2163          * call it before checking allow_preemptive_ff.
2164          */
2165         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
2166                     &options.orig_head, &merge_base) &&
2167             allow_preemptive_ff) {
2168                 int flag;
2169
2170                 if (!(options.flags & REBASE_FORCE)) {
2171                         /* Lazily switch to the target branch if needed... */
2172                         if (options.switch_to) {
2173                                 struct object_id oid;
2174
2175                                 if (get_oid(options.switch_to, &oid) < 0) {
2176                                         ret = !!error(_("could not parse '%s'"),
2177                                                       options.switch_to);
2178                                         goto cleanup;
2179                                 }
2180
2181                                 strbuf_reset(&buf);
2182                                 strbuf_addf(&buf, "%s: checkout %s",
2183                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2184                                             options.switch_to);
2185                                 if (reset_head(&oid, "checkout",
2186                                                options.head_name,
2187                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2188                                                NULL, buf.buf) < 0) {
2189                                         ret = !!error(_("could not switch to "
2190                                                         "%s"),
2191                                                       options.switch_to);
2192                                         goto cleanup;
2193                                 }
2194                         }
2195
2196                         if (!(options.flags & REBASE_NO_QUIET))
2197                                 ; /* be quiet */
2198                         else if (!strcmp(branch_name, "HEAD") &&
2199                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2200                                 puts(_("HEAD is up to date."));
2201                         else
2202                                 printf(_("Current branch %s is up to date.\n"),
2203                                        branch_name);
2204                         ret = !!finish_rebase(&options);
2205                         goto cleanup;
2206                 } else if (!(options.flags & REBASE_NO_QUIET))
2207                         ; /* be quiet */
2208                 else if (!strcmp(branch_name, "HEAD") &&
2209                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2210                         puts(_("HEAD is up to date, rebase forced."));
2211                 else
2212                         printf(_("Current branch %s is up to date, rebase "
2213                                  "forced.\n"), branch_name);
2214         }
2215
2216         /* If a hook exists, give it a chance to interrupt*/
2217         if (!ok_to_skip_pre_rebase &&
2218             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2219                         argc ? argv[0] : NULL, NULL))
2220                 die(_("The pre-rebase hook refused to rebase."));
2221
2222         if (options.flags & REBASE_DIFFSTAT) {
2223                 struct diff_options opts;
2224
2225                 if (options.flags & REBASE_VERBOSE) {
2226                         if (is_null_oid(&merge_base))
2227                                 printf(_("Changes to %s:\n"),
2228                                        oid_to_hex(&options.onto->object.oid));
2229                         else
2230                                 printf(_("Changes from %s to %s:\n"),
2231                                        oid_to_hex(&merge_base),
2232                                        oid_to_hex(&options.onto->object.oid));
2233                 }
2234
2235                 /* We want color (if set), but no pager */
2236                 diff_setup(&opts);
2237                 opts.stat_width = -1; /* use full terminal width */
2238                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2239                 opts.output_format |=
2240                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2241                 opts.detect_rename = DIFF_DETECT_RENAME;
2242                 diff_setup_done(&opts);
2243                 diff_tree_oid(is_null_oid(&merge_base) ?
2244                               the_hash_algo->empty_tree : &merge_base,
2245                               &options.onto->object.oid, "", &opts);
2246                 diffcore_std(&opts);
2247                 diff_flush(&opts);
2248         }
2249
2250         if (is_interactive(&options))
2251                 goto run_rebase;
2252
2253         /* Detach HEAD and reset the tree */
2254         if (options.flags & REBASE_NO_QUIET)
2255                 printf(_("First, rewinding head to replay your work on top of "
2256                          "it...\n"));
2257
2258         strbuf_addf(&msg, "%s: checkout %s",
2259                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2260         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2261                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2262                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2263                        NULL, msg.buf))
2264                 die(_("Could not detach HEAD"));
2265         strbuf_release(&msg);
2266
2267         /*
2268          * If the onto is a proper descendant of the tip of the branch, then
2269          * we just fast-forwarded.
2270          */
2271         strbuf_reset(&msg);
2272         if (oideq(&merge_base, &options.orig_head)) {
2273                 printf(_("Fast-forwarded %s to %s.\n"),
2274                         branch_name, options.onto_name);
2275                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2276                         options.head_name ? options.head_name : "detached HEAD",
2277                         oid_to_hex(&options.onto->object.oid));
2278                 reset_head(NULL, "Fast-forwarded", options.head_name,
2279                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2280                 strbuf_release(&msg);
2281                 ret = !!finish_rebase(&options);
2282                 goto cleanup;
2283         }
2284
2285         strbuf_addf(&revisions, "%s..%s",
2286                     options.root ? oid_to_hex(&options.onto->object.oid) :
2287                     (options.restrict_revision ?
2288                      oid_to_hex(&options.restrict_revision->object.oid) :
2289                      oid_to_hex(&options.upstream->object.oid)),
2290                     oid_to_hex(&options.orig_head));
2291
2292         options.revisions = revisions.buf;
2293
2294 run_rebase:
2295         ret = !!run_specific_rebase(&options, action);
2296
2297 cleanup:
2298         strbuf_release(&buf);
2299         strbuf_release(&revisions);
2300         free(options.head_name);
2301         free(options.gpg_sign_opt);
2302         free(options.cmd);
2303         free(squash_onto_name);
2304         return ret;
2305 }