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_APPLY,
  48         REBASE_MERGE,
  49         REBASE_PRESERVE_MERGES
  50 };
  51
  52 enum empty_type {
  53         EMPTY_UNSPECIFIED = -1,
  54         EMPTY_DROP,
  55         EMPTY_KEEP,
  56         EMPTY_ASK
  57 };
  58
  59 struct rebase_options {
  60         enum rebase_type type;
  61         enum empty_type empty;
  62         const char *default_backend;
  63         const char *state_dir;
  64         struct commit *upstream;
  65         const char *upstream_name;
  66         const char *upstream_arg;
  67         char *head_name;
  68         struct object_id orig_head;
  69         struct commit *onto;
  70         const char *onto_name;
  71         const char *revisions;
  72         const char *switch_to;
  73         int root, root_with_onto;
  74         struct object_id *squash_onto;
  75         struct commit *restrict_revision;
  76         int dont_finish_rebase;
  77         enum {
  78                 REBASE_NO_QUIET = 1<<0,
  79                 REBASE_VERBOSE = 1<<1,
  80                 REBASE_DIFFSTAT = 1<<2,
  81                 REBASE_FORCE = 1<<3,
  82                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  83         } flags;
  84         struct argv_array git_am_opts;
  85         const char *action;
  86         int signoff;
  87         int allow_rerere_autoupdate;
  88         int keep_empty;
  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         int reapply_cherry_picks;
 100 };
 101
 102 #define REBASE_OPTIONS_INIT {                           \
 103                 .type = REBASE_UNSPECIFIED,             \
 104                 .empty = EMPTY_UNSPECIFIED,             \
 105                 .keep_empty = 1,                        \
 106                 .default_backend = "merge",             \
 107                 .flags = REBASE_NO_QUIET,               \
 108                 .git_am_opts = ARGV_ARRAY_INIT,         \
 109                 .git_format_patch_opt = STRBUF_INIT     \
 110         }
 111
 112 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 113 {
 114         struct replay_opts replay = REPLAY_OPTS_INIT;
 115
 116         replay.action = REPLAY_INTERACTIVE_REBASE;
 117         sequencer_init_config(&replay);
 118
 119         replay.signoff = opts->signoff;
 120         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 121         if (opts->allow_rerere_autoupdate)
 122                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 123         replay.allow_empty = 1;
 124         replay.allow_empty_message = opts->allow_empty_message;
 125         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
 126         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
 127         replay.quiet = !(opts->flags & REBASE_NO_QUIET);
 128         replay.verbose = opts->flags & REBASE_VERBOSE;
 129         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 130         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 131         replay.strategy = opts->strategy;
 132         if (opts->strategy_opts)
 133                 parse_strategy_opts(&replay, opts->strategy_opts);
 134
 135         if (opts->squash_onto) {
 136                 oidcpy(&replay.squash_onto, opts->squash_onto);
 137                 replay.have_squash_onto = 1;
 138         }
 139
 140         return replay;
 141 }
 142
 143 enum action {
 144         ACTION_NONE = 0,
 145         ACTION_CONTINUE,
 146         ACTION_SKIP,
 147         ACTION_ABORT,
 148         ACTION_QUIT,
 149         ACTION_EDIT_TODO,
 150         ACTION_SHOW_CURRENT_PATCH,
 151         ACTION_SHORTEN_OIDS,
 152         ACTION_EXPAND_OIDS,
 153         ACTION_CHECK_TODO_LIST,
 154         ACTION_REARRANGE_SQUASH,
 155         ACTION_ADD_EXEC
 156 };
 157
 158 static const char *action_names[] = { "undefined",
 159                                       "continue",
 160                                       "skip",
 161                                       "abort",
 162                                       "quit",
 163                                       "edit_todo",
 164                                       "show_current_patch" };
 165
 166 static int add_exec_commands(struct string_list *commands)
 167 {
 168         const char *todo_file = rebase_path_todo();
 169         struct todo_list todo_list = TODO_LIST_INIT;
 170         int res;
 171
 172         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 173                 return error_errno(_("could not read '%s'."), todo_file);
 174
 175         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 176                                         &todo_list)) {
 177                 todo_list_release(&todo_list);
 178                 return error(_("unusable todo list: '%s'"), todo_file);
 179         }
 180
 181         todo_list_add_exec_commands(&todo_list, commands);
 182         res = todo_list_write_to_file(the_repository, &todo_list,
 183                                       todo_file, NULL, NULL, -1, 0);
 184         todo_list_release(&todo_list);
 185
 186         if (res)
 187                 return error_errno(_("could not write '%s'."), todo_file);
 188         return 0;
 189 }
 190
 191 static int rearrange_squash_in_todo_file(void)
 192 {
 193         const char *todo_file = rebase_path_todo();
 194         struct todo_list todo_list = TODO_LIST_INIT;
 195         int res = 0;
 196
 197         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 198                 return error_errno(_("could not read '%s'."), todo_file);
 199         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 200                                         &todo_list)) {
 201                 todo_list_release(&todo_list);
 202                 return error(_("unusable todo list: '%s'"), todo_file);
 203         }
 204
 205         res = todo_list_rearrange_squash(&todo_list);
 206         if (!res)
 207                 res = todo_list_write_to_file(the_repository, &todo_list,
 208                                               todo_file, NULL, NULL, -1, 0);
 209
 210         todo_list_release(&todo_list);
 211
 212         if (res)
 213                 return error_errno(_("could not write '%s'."), todo_file);
 214         return 0;
 215 }
 216
 217 static int transform_todo_file(unsigned flags)
 218 {
 219         const char *todo_file = rebase_path_todo();
 220         struct todo_list todo_list = TODO_LIST_INIT;
 221         int res;
 222
 223         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 224                 return error_errno(_("could not read '%s'."), todo_file);
 225
 226         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 227                                         &todo_list)) {
 228                 todo_list_release(&todo_list);
 229                 return error(_("unusable todo list: '%s'"), todo_file);
 230         }
 231
 232         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 233                                       NULL, NULL, -1, flags);
 234         todo_list_release(&todo_list);
 235
 236         if (res)
 237                 return error_errno(_("could not write '%s'."), todo_file);
 238         return 0;
 239 }
 240
 241 static int edit_todo_file(unsigned flags)
 242 {
 243         const char *todo_file = rebase_path_todo();
 244         struct todo_list todo_list = TODO_LIST_INIT,
 245                 new_todo = TODO_LIST_INIT;
 246         int res = 0;
 247
 248         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 249                 return error_errno(_("could not read '%s'."), todo_file);
 250
 251         strbuf_stripspace(&todo_list.buf, 1);
 252         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 253         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 254                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 255                 res = error_errno(_("could not write '%s'"), todo_file);
 256
 257         todo_list_release(&todo_list);
 258         todo_list_release(&new_todo);
 259
 260         return res;
 261 }
 262
 263 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 264                                struct object_id *orig_head, const char **head_hash,
 265                                char **revisions, char **shortrevisions)
 266 {
 267         struct commit *base_rev = upstream ? upstream : onto;
 268         const char *shorthead;
 269
 270         *head_hash = find_unique_abbrev(orig_head, GIT_MAX_HEXSZ);
 271         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 272                                                    *head_hash);
 273
 274         shorthead = find_unique_abbrev(orig_head, DEFAULT_ABBREV);
 275
 276         if (upstream) {
 277                 const char *shortrev;
 278
 279                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 280                                               DEFAULT_ABBREV);
 281
 282                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 283         } else
 284                 *shortrevisions = xstrdup(shorthead);
 285
 286         return 0;
 287 }
 288
 289 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 290                             struct commit *onto, const char *orig_head)
 291 {
 292         FILE *interactive;
 293
 294         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 295                 return error_errno(_("could not create temporary %s"), merge_dir());
 296
 297         delete_reflog("REBASE_HEAD");
 298
 299         interactive = fopen(path_interactive(), "w");
 300         if (!interactive)
 301                 return error_errno(_("could not mark as interactive"));
 302         fclose(interactive);
 303
 304         return write_basic_state(opts, head_name, onto, orig_head);
 305 }
 306
 307 static void split_exec_commands(const char *cmd, struct string_list *commands)
 308 {
 309         if (cmd && *cmd) {
 310                 string_list_split(commands, cmd, '\n', -1);
 311
 312                 /* rebase.c adds a new line to cmd after every command,
 313                  * so here the last command is always empty */
 314                 string_list_remove_empty_items(commands, 0);
 315         }
 316 }
 317
 318 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 319 {
 320         int ret;
 321         const char *head_hash = NULL;
 322         char *revisions = NULL, *shortrevisions = NULL;
 323         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 324         struct todo_list todo_list = TODO_LIST_INIT;
 325         struct replay_opts replay = get_replay_opts(opts);
 326         struct string_list commands = STRING_LIST_INIT_DUP;
 327
 328         if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head,
 329                                 &head_hash, &revisions, &shortrevisions))
 330                 return -1;
 331
 332         if (init_basic_state(&replay,
 333                              opts->head_name ? opts->head_name : "detached HEAD",
 334                              opts->onto, head_hash)) {
 335                 free(revisions);
 336                 free(shortrevisions);
 337
 338                 return -1;
 339         }
 340
 341         if (!opts->upstream && opts->squash_onto)
 342                 write_file(path_squash_onto(), "%s\n",
 343                            oid_to_hex(opts->squash_onto));
 344
 345         argv_array_pushl(&make_script_args, "", revisions, NULL);
 346         if (opts->restrict_revision)
 347                 argv_array_pushf(&make_script_args, "^%s",
 348                                  oid_to_hex(&opts->restrict_revision->object.oid));
 349
 350         ret = sequencer_make_script(the_repository, &todo_list.buf,
 351                                     make_script_args.argc, make_script_args.argv,
 352                                     flags);
 353
 354         if (ret)
 355                 error(_("could not generate todo list"));
 356         else {
 357                 discard_cache();
 358                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 359                                                 &todo_list))
 360                         BUG("unusable todo list");
 361
 362                 split_exec_commands(opts->cmd, &commands);
 363                 ret = complete_action(the_repository, &replay, flags,
 364                         shortrevisions, opts->onto_name, opts->onto, head_hash,
 365                         &commands, opts->autosquash, &todo_list);
 366         }
 367
 368         string_list_clear(&commands, 0);
 369         free(revisions);
 370         free(shortrevisions);
 371         todo_list_release(&todo_list);
 372         argv_array_clear(&make_script_args);
 373
 374         return ret;
 375 }
 376
 377 static int run_sequencer_rebase(struct rebase_options *opts,
 378                                   enum action command)
 379 {
 380         unsigned flags = 0;
 381         int abbreviate_commands = 0, ret = 0;
 382
 383         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 384
 385         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 386         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 387         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 388         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 389         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 390         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 391         flags |= opts->reapply_cherry_picks ? TODO_LIST_REAPPLY_CHERRY_PICKS : 0;
 392
 393         switch (command) {
 394         case ACTION_NONE: {
 395                 if (!opts->onto && !opts->upstream)
 396                         die(_("a base commit must be provided with --upstream or --onto"));
 397
 398                 ret = do_interactive_rebase(opts, flags);
 399                 break;
 400         }
 401         case ACTION_SKIP: {
 402                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 403
 404                 rerere_clear(the_repository, &merge_rr);
 405         }
 406                 /* fallthrough */
 407         case ACTION_CONTINUE: {
 408                 struct replay_opts replay_opts = get_replay_opts(opts);
 409
 410                 ret = sequencer_continue(the_repository, &replay_opts);
 411                 break;
 412         }
 413         case ACTION_EDIT_TODO:
 414                 ret = edit_todo_file(flags);
 415                 break;
 416         case ACTION_SHOW_CURRENT_PATCH: {
 417                 struct child_process cmd = CHILD_PROCESS_INIT;
 418
 419                 cmd.git_cmd = 1;
 420                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 421                 ret = run_command(&cmd);
 422
 423                 break;
 424         }
 425         case ACTION_SHORTEN_OIDS:
 426         case ACTION_EXPAND_OIDS:
 427                 ret = transform_todo_file(flags);
 428                 break;
 429         case ACTION_CHECK_TODO_LIST:
 430                 ret = check_todo_list_from_file(the_repository);
 431                 break;
 432         case ACTION_REARRANGE_SQUASH:
 433                 ret = rearrange_squash_in_todo_file();
 434                 break;
 435         case ACTION_ADD_EXEC: {
 436                 struct string_list commands = STRING_LIST_INIT_DUP;
 437
 438                 split_exec_commands(opts->cmd, &commands);
 439                 ret = add_exec_commands(&commands);
 440                 string_list_clear(&commands, 0);
 441                 break;
 442         }
 443         default:
 444                 BUG("invalid command '%d'", command);
 445         }
 446
 447         return ret;
 448 }
 449
 450 static void imply_merge(struct rebase_options *opts, const char *option);
 451 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 452                                 int unset)
 453 {
 454         struct rebase_options *opts = opt->value;
 455
 456         BUG_ON_OPT_ARG(arg);
 457
 458         imply_merge(opts, unset ? "--no-keep-empty" : "--keep-empty");
 459         opts->keep_empty = !unset;
 460         opts->type = REBASE_MERGE;
 461         return 0;
 462 }
 463
 464 static const char * const builtin_rebase_interactive_usage[] = {
 465         N_("git rebase--interactive [<options>]"),
 466         NULL
 467 };
 468
 469 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 470 {
 471         struct rebase_options opts = REBASE_OPTIONS_INIT;
 472         struct object_id squash_onto = null_oid;
 473         enum action command = ACTION_NONE;
 474         struct option options[] = {
 475                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 476                            REBASE_FORCE),
 477                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
 478                         N_("keep commits which start empty"),
 479                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
 480                         parse_opt_keep_empty },
 481                 OPT_BOOL_F(0, "allow-empty-message", &opts.allow_empty_message,
 482                            N_("allow commits with empty messages"),
 483                            PARSE_OPT_HIDDEN),
 484                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 485                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 486                          N_("keep original branch points of cousins")),
 487                 OPT_BOOL(0, "autosquash", &opts.autosquash,
 488                          N_("move commits that begin with squash!/fixup!")),
 489                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 490                 OPT_BIT('v', "verbose", &opts.flags,
 491                         N_("display a diffstat of what changed upstream"),
 492                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 493                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 494                             ACTION_CONTINUE),
 495                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 496                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 497                             ACTION_EDIT_TODO),
 498                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 499                             ACTION_SHOW_CURRENT_PATCH),
 500                 OPT_CMDMODE(0, "shorten-ids", &command,
 501                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 502                 OPT_CMDMODE(0, "expand-ids", &command,
 503                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 504                 OPT_CMDMODE(0, "check-todo-list", &command,
 505                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 506                 OPT_CMDMODE(0, "rearrange-squash", &command,
 507                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 508                 OPT_CMDMODE(0, "add-exec-commands", &command,
 509                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 510                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 511                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 512                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 513                   N_("restrict-revision"), N_("restrict revision"),
 514                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 515                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 516                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 517                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 518                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 519                   0 },
 520                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 521                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 522                         N_("GPG-sign commits"),
 523                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 524                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 525                            N_("rebase strategy")),
 526                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 527                            N_("strategy options")),
 528                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 529                            N_("the branch or commit to checkout")),
 530                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 531                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 532                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 533                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 534                          N_("automatically re-schedule any `exec` that fails")),
 535                 OPT_END()
 536         };
 537
 538         opts.rebase_cousins = -1;
 539
 540         if (argc == 1)
 541                 usage_with_options(builtin_rebase_interactive_usage, options);
 542
 543         argc = parse_options(argc, argv, prefix, options,
 544                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 545
 546         if (!is_null_oid(&squash_onto))
 547                 opts.squash_onto = &squash_onto;
 548
 549         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 550                 warning(_("--[no-]rebase-cousins has no effect without "
 551                           "--rebase-merges"));
 552
 553         return !!run_sequencer_rebase(&opts, command);
 554 }
 555
 556 static int is_merge(struct rebase_options *opts)
 557 {
 558         return opts->type == REBASE_MERGE ||
 559                 opts->type == REBASE_PRESERVE_MERGES;
 560 }
 561
 562 static void imply_merge(struct rebase_options *opts, const char *option)
 563 {
 564         switch (opts->type) {
 565         case REBASE_APPLY:
 566                 die(_("%s requires the merge backend"), option);
 567                 break;
 568         case REBASE_MERGE:
 569         case REBASE_PRESERVE_MERGES:
 570                 break;
 571         default:
 572                 opts->type = REBASE_MERGE; /* implied */
 573                 break;
 574         }
 575 }
 576
 577 /* Returns the filename prefixed by the state_dir */
 578 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 579 {
 580         static struct strbuf path = STRBUF_INIT;
 581         static size_t prefix_len;
 582
 583         if (!prefix_len) {
 584                 strbuf_addf(&path, "%s/", opts->state_dir);
 585                 prefix_len = path.len;
 586         }
 587
 588         strbuf_setlen(&path, prefix_len);
 589         strbuf_addstr(&path, filename);
 590         return path.buf;
 591 }
 592
 593 /* Read one file, then strip line endings */
 594 static int read_one(const char *path, struct strbuf *buf)
 595 {
 596         if (strbuf_read_file(buf, path, 0) < 0)
 597                 return error_errno(_("could not read '%s'"), path);
 598         strbuf_trim_trailing_newline(buf);
 599         return 0;
 600 }
 601
 602 /* Initialize the rebase options from the state directory. */
 603 static int read_basic_state(struct rebase_options *opts)
 604 {
 605         struct strbuf head_name = STRBUF_INIT;
 606         struct strbuf buf = STRBUF_INIT;
 607         struct object_id oid;
 608
 609         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 610             read_one(state_dir_path("onto", opts), &buf))
 611                 return -1;
 612         opts->head_name = starts_with(head_name.buf, "refs/") ?
 613                 xstrdup(head_name.buf) : NULL;
 614         strbuf_release(&head_name);
 615         if (get_oid(buf.buf, &oid))
 616                 return error(_("could not get 'onto': '%s'"), buf.buf);
 617         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 618
 619         /*
 620          * We always write to orig-head, but interactive rebase used to write to
 621          * head. Fall back to reading from head to cover for the case that the
 622          * user upgraded git with an ongoing interactive rebase.
 623          */
 624         strbuf_reset(&buf);
 625         if (file_exists(state_dir_path("orig-head", opts))) {
 626                 if (read_one(state_dir_path("orig-head", opts), &buf))
 627                         return -1;
 628         } else if (read_one(state_dir_path("head", opts), &buf))
 629                 return -1;
 630         if (get_oid(buf.buf, &opts->orig_head))
 631                 return error(_("invalid orig-head: '%s'"), buf.buf);
 632
 633         if (file_exists(state_dir_path("quiet", opts)))
 634                 opts->flags &= ~REBASE_NO_QUIET;
 635         else
 636                 opts->flags |= REBASE_NO_QUIET;
 637
 638         if (file_exists(state_dir_path("verbose", opts)))
 639                 opts->flags |= REBASE_VERBOSE;
 640
 641         if (file_exists(state_dir_path("signoff", opts))) {
 642                 opts->signoff = 1;
 643                 opts->flags |= REBASE_FORCE;
 644         }
 645
 646         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 647                 strbuf_reset(&buf);
 648                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 649                             &buf))
 650                         return -1;
 651                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 652                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 653                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 654                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 655                 else
 656                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 657                                   "'%s'"), buf.buf);
 658         }
 659
 660         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 661                 strbuf_reset(&buf);
 662                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 663                             &buf))
 664                         return -1;
 665                 free(opts->gpg_sign_opt);
 666                 opts->gpg_sign_opt = xstrdup(buf.buf);
 667         }
 668
 669         if (file_exists(state_dir_path("strategy", opts))) {
 670                 strbuf_reset(&buf);
 671                 if (read_one(state_dir_path("strategy", opts), &buf))
 672                         return -1;
 673                 free(opts->strategy);
 674                 opts->strategy = xstrdup(buf.buf);
 675         }
 676
 677         if (file_exists(state_dir_path("strategy_opts", opts))) {
 678                 strbuf_reset(&buf);
 679                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 680                         return -1;
 681                 free(opts->strategy_opts);
 682                 opts->strategy_opts = xstrdup(buf.buf);
 683         }
 684
 685         strbuf_release(&buf);
 686
 687         return 0;
 688 }
 689
 690 static int rebase_write_basic_state(struct rebase_options *opts)
 691 {
 692         write_file(state_dir_path("head-name", opts), "%s",
 693                    opts->head_name ? opts->head_name : "detached HEAD");
 694         write_file(state_dir_path("onto", opts), "%s",
 695                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 696         write_file(state_dir_path("orig-head", opts), "%s",
 697                    oid_to_hex(&opts->orig_head));
 698         if (!(opts->flags & REBASE_NO_QUIET))
 699                 write_file(state_dir_path("quiet", opts), "%s", "");
 700         if (opts->flags & REBASE_VERBOSE)
 701                 write_file(state_dir_path("verbose", opts), "%s", "");
 702         if (opts->strategy)
 703                 write_file(state_dir_path("strategy", opts), "%s",
 704                            opts->strategy);
 705         if (opts->strategy_opts)
 706                 write_file(state_dir_path("strategy_opts", opts), "%s",
 707                            opts->strategy_opts);
 708         if (opts->allow_rerere_autoupdate > 0)
 709                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 710                            "-%s-rerere-autoupdate",
 711                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 712                                 "" : "-no");
 713         if (opts->gpg_sign_opt)
 714                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 715                            opts->gpg_sign_opt);
 716         if (opts->signoff)
 717                 write_file(state_dir_path("signoff", opts), "--signoff");
 718
 719         return 0;
 720 }
 721
 722 static int apply_autostash(struct rebase_options *opts)
 723 {
 724         const char *path = state_dir_path("autostash", opts);
 725         struct strbuf autostash = STRBUF_INIT;
 726         struct child_process stash_apply = CHILD_PROCESS_INIT;
 727
 728         if (!file_exists(path))
 729                 return 0;
 730
 731         if (read_one(path, &autostash))
 732                 return error(_("Could not read '%s'"), path);
 733         /* Ensure that the hash is not mistaken for a number */
 734         strbuf_addstr(&autostash, "^0");
 735         argv_array_pushl(&stash_apply.args,
 736                          "stash", "apply", autostash.buf, NULL);
 737         stash_apply.git_cmd = 1;
 738         stash_apply.no_stderr = stash_apply.no_stdout =
 739                 stash_apply.no_stdin = 1;
 740         if (!run_command(&stash_apply))
 741                 printf(_("Applied autostash.\n"));
 742         else {
 743                 struct argv_array args = ARGV_ARRAY_INIT;
 744                 int res = 0;
 745
 746                 argv_array_pushl(&args,
 747                                  "stash", "store", "-m", "autostash", "-q",
 748                                  autostash.buf, NULL);
 749                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 750                         res = error(_("Cannot store %s"), autostash.buf);
 751                 argv_array_clear(&args);
 752                 strbuf_release(&autostash);
 753                 if (res)
 754                         return res;
 755
 756                 fprintf(stderr,
 757                         _("Applying autostash resulted in conflicts.\n"
 758                           "Your changes are safe in the stash.\n"
 759                           "You can run \"git stash pop\" or \"git stash drop\" "
 760                           "at any time.\n"));
 761         }
 762
 763         strbuf_release(&autostash);
 764         return 0;
 765 }
 766
 767 static int finish_rebase(struct rebase_options *opts)
 768 {
 769         struct strbuf dir = STRBUF_INIT;
 770         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 771         int ret = 0;
 772
 773         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 774         apply_autostash(opts);
 775         close_object_store(the_repository->objects);
 776         /*
 777          * We ignore errors in 'gc --auto', since the
 778          * user should see them.
 779          */
 780         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 781         if (opts->type == REBASE_MERGE) {
 782                 struct replay_opts replay = REPLAY_OPTS_INIT;
 783
 784                 replay.action = REPLAY_INTERACTIVE_REBASE;
 785                 ret = sequencer_remove_state(&replay);
 786         } else {
 787                 strbuf_addstr(&dir, opts->state_dir);
 788                 if (remove_dir_recursively(&dir, 0))
 789                         ret = error(_("could not remove '%s'"),
 790                                     opts->state_dir);
 791                 strbuf_release(&dir);
 792         }
 793
 794         return ret;
 795 }
 796
 797 static struct commit *peel_committish(const char *name)
 798 {
 799         struct object *obj;
 800         struct object_id oid;
 801
 802         if (get_oid(name, &oid))
 803                 return NULL;
 804         obj = parse_object(the_repository, &oid);
 805         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 806 }
 807
 808 static void add_var(struct strbuf *buf, const char *name, const char *value)
 809 {
 810         if (!value)
 811                 strbuf_addf(buf, "unset %s; ", name);
 812         else {
 813                 strbuf_addf(buf, "%s=", name);
 814                 sq_quote_buf(buf, value);
 815                 strbuf_addstr(buf, "; ");
 816         }
 817 }
 818
 819 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 820
 821 #define RESET_HEAD_DETACH (1<<0)
 822 #define RESET_HEAD_HARD (1<<1)
 823 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 824 #define RESET_HEAD_REFS_ONLY (1<<3)
 825 #define RESET_ORIG_HEAD (1<<4)
 826
 827 static int reset_head(struct object_id *oid, const char *action,
 828                       const char *switch_to_branch, unsigned flags,
 829                       const char *reflog_orig_head, const char *reflog_head)
 830 {
 831         unsigned detach_head = flags & RESET_HEAD_DETACH;
 832         unsigned reset_hard = flags & RESET_HEAD_HARD;
 833         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 834         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 835         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 836         struct object_id head_oid;
 837         struct tree_desc desc[2] = { { NULL }, { NULL } };
 838         struct lock_file lock = LOCK_INIT;
 839         struct unpack_trees_options unpack_tree_opts;
 840         struct tree *tree;
 841         const char *reflog_action;
 842         struct strbuf msg = STRBUF_INIT;
 843         size_t prefix_len;
 844         struct object_id *orig = NULL, oid_orig,
 845                 *old_orig = NULL, oid_old_orig;
 846         int ret = 0, nr = 0;
 847
 848         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 849                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 850
 851         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 852                 ret = -1;
 853                 goto leave_reset_head;
 854         }
 855
 856         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 857                 ret = error(_("could not determine HEAD revision"));
 858                 goto leave_reset_head;
 859         }
 860
 861         if (!oid)
 862                 oid = &head_oid;
 863
 864         if (refs_only)
 865                 goto reset_head_refs;
 866
 867         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 868         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 869         unpack_tree_opts.head_idx = 1;
 870         unpack_tree_opts.src_index = the_repository->index;
 871         unpack_tree_opts.dst_index = the_repository->index;
 872         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 873         unpack_tree_opts.update = 1;
 874         unpack_tree_opts.merge = 1;
 875         init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
 876         if (!detach_head)
 877                 unpack_tree_opts.reset = 1;
 878
 879         if (repo_read_index_unmerged(the_repository) < 0) {
 880                 ret = error(_("could not read index"));
 881                 goto leave_reset_head;
 882         }
 883
 884         if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 885                 ret = error(_("failed to find tree of %s"),
 886                             oid_to_hex(&head_oid));
 887                 goto leave_reset_head;
 888         }
 889
 890         if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 891                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 892                 goto leave_reset_head;
 893         }
 894
 895         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 896                 ret = -1;
 897                 goto leave_reset_head;
 898         }
 899
 900         tree = parse_tree_indirect(oid);
 901         prime_cache_tree(the_repository, the_repository->index, tree);
 902
 903         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 904                 ret = error(_("could not write index"));
 905                 goto leave_reset_head;
 906         }
 907
 908 reset_head_refs:
 909         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 910         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 911         prefix_len = msg.len;
 912
 913         if (update_orig_head) {
 914                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 915                         old_orig = &oid_old_orig;
 916                 if (!get_oid("HEAD", &oid_orig)) {
 917                         orig = &oid_orig;
 918                         if (!reflog_orig_head) {
 919                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 920                                 reflog_orig_head = msg.buf;
 921                         }
 922                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 923                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 924                 } else if (old_orig)
 925                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 926         }
 927
 928         if (!reflog_head) {
 929                 strbuf_setlen(&msg, prefix_len);
 930                 strbuf_addstr(&msg, "updating HEAD");
 931                 reflog_head = msg.buf;
 932         }
 933         if (!switch_to_branch)
 934                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 935                                  detach_head ? REF_NO_DEREF : 0,
 936                                  UPDATE_REFS_MSG_ON_ERR);
 937         else {
 938                 ret = update_ref(reflog_head, switch_to_branch, oid,
 939                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 940                 if (!ret)
 941                         ret = create_symref("HEAD", switch_to_branch,
 942                                             reflog_head);
 943         }
 944         if (run_hook)
 945                 run_hook_le(NULL, "post-checkout",
 946                             oid_to_hex(orig ? orig : &null_oid),
 947                             oid_to_hex(oid), "1", NULL);
 948
 949 leave_reset_head:
 950         strbuf_release(&msg);
 951         rollback_lock_file(&lock);
 952         while (nr)
 953                 free((void *)desc[--nr].buffer);
 954         return ret;
 955 }
 956
 957 static int move_to_original_branch(struct rebase_options *opts)
 958 {
 959         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 960         int ret;
 961
 962         if (!opts->head_name)
 963                 return 0; /* nothing to move back to */
 964
 965         if (!opts->onto)
 966                 BUG("move_to_original_branch without onto");
 967
 968         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 969                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 970         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 971                     opts->head_name);
 972         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 973                          orig_head_reflog.buf, head_reflog.buf);
 974
 975         strbuf_release(&orig_head_reflog);
 976         strbuf_release(&head_reflog);
 977         return ret;
 978 }
 979
 980 static const char *resolvemsg =
 981 N_("Resolve all conflicts manually, mark them as resolved with\n"
 982 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 983 "You can instead skip this commit: run \"git rebase --skip\".\n"
 984 "To abort and get back to the state before \"git rebase\", run "
 985 "\"git rebase --abort\".");
 986
 987 static int run_am(struct rebase_options *opts)
 988 {
 989         struct child_process am = CHILD_PROCESS_INIT;
 990         struct child_process format_patch = CHILD_PROCESS_INIT;
 991         struct strbuf revisions = STRBUF_INIT;
 992         int status;
 993         char *rebased_patches;
 994
 995         am.git_cmd = 1;
 996         argv_array_push(&am.args, "am");
 997
 998         if (opts->action && !strcmp("continue", opts->action)) {
 999                 argv_array_push(&am.args, "--resolved");
1000                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1001                 if (opts->gpg_sign_opt)
1002                         argv_array_push(&am.args, opts->gpg_sign_opt);
1003                 status = run_command(&am);
1004                 if (status)
1005                         return status;
1006
1007                 return move_to_original_branch(opts);
1008         }
1009         if (opts->action && !strcmp("skip", opts->action)) {
1010                 argv_array_push(&am.args, "--skip");
1011                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1012                 status = run_command(&am);
1013                 if (status)
1014                         return status;
1015
1016                 return move_to_original_branch(opts);
1017         }
1018         if (opts->action && !strcmp("show-current-patch", opts->action)) {
1019                 argv_array_push(&am.args, "--show-current-patch");
1020                 return run_command(&am);
1021         }
1022
1023         strbuf_addf(&revisions, "%s...%s",
1024                     oid_to_hex(opts->root ?
1025                                /* this is now equivalent to !opts->upstream */
1026                                &opts->onto->object.oid :
1027                                &opts->upstream->object.oid),
1028                     oid_to_hex(&opts->orig_head));
1029
1030         rebased_patches = xstrdup(git_path("rebased-patches"));
1031         format_patch.out = open(rebased_patches,
1032                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1033         if (format_patch.out < 0) {
1034                 status = error_errno(_("could not open '%s' for writing"),
1035                                      rebased_patches);
1036                 free(rebased_patches);
1037                 argv_array_clear(&am.args);
1038                 return status;
1039         }
1040
1041         format_patch.git_cmd = 1;
1042         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1043                          "--full-index", "--cherry-pick", "--right-only",
1044                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1045                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
1046                          "--no-base", NULL);
1047         if (opts->git_format_patch_opt.len)
1048                 argv_array_split(&format_patch.args,
1049                                  opts->git_format_patch_opt.buf);
1050         argv_array_push(&format_patch.args, revisions.buf);
1051         if (opts->restrict_revision)
1052                 argv_array_pushf(&format_patch.args, "^%s",
1053                                  oid_to_hex(&opts->restrict_revision->object.oid));
1054
1055         status = run_command(&format_patch);
1056         if (status) {
1057                 unlink(rebased_patches);
1058                 free(rebased_patches);
1059                 argv_array_clear(&am.args);
1060
1061                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1062                            "HEAD", NULL);
1063                 error(_("\ngit encountered an error while preparing the "
1064                         "patches to replay\n"
1065                         "these revisions:\n"
1066                         "\n    %s\n\n"
1067                         "As a result, git cannot rebase them."),
1068                       opts->revisions);
1069
1070                 strbuf_release(&revisions);
1071                 return status;
1072         }
1073         strbuf_release(&revisions);
1074
1075         am.in = open(rebased_patches, O_RDONLY);
1076         if (am.in < 0) {
1077                 status = error_errno(_("could not open '%s' for reading"),
1078                                      rebased_patches);
1079                 free(rebased_patches);
1080                 argv_array_clear(&am.args);
1081                 return status;
1082         }
1083
1084         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1085         argv_array_push(&am.args, "--rebasing");
1086         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1087         argv_array_push(&am.args, "--patch-format=mboxrd");
1088         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1089                 argv_array_push(&am.args, "--rerere-autoupdate");
1090         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1091                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1092         if (opts->gpg_sign_opt)
1093                 argv_array_push(&am.args, opts->gpg_sign_opt);
1094         status = run_command(&am);
1095         unlink(rebased_patches);
1096         free(rebased_patches);
1097
1098         if (!status) {
1099                 return move_to_original_branch(opts);
1100         }
1101
1102         if (is_directory(opts->state_dir))
1103                 rebase_write_basic_state(opts);
1104
1105         return status;
1106 }
1107
1108 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1109 {
1110         const char *argv[] = { NULL, NULL };
1111         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1112         int status;
1113         const char *backend, *backend_func;
1114
1115         if (opts->type == REBASE_MERGE) {
1116                 /* Run sequencer-based rebase */
1117                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1118                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1119                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1120                         opts->autosquash = 0;
1121                 }
1122                 if (opts->gpg_sign_opt) {
1123                         /* remove the leading "-S" */
1124                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1125                         free(opts->gpg_sign_opt);
1126                         opts->gpg_sign_opt = tmp;
1127                 }
1128
1129                 status = run_sequencer_rebase(opts, action);
1130                 goto finished_rebase;
1131         }
1132
1133         if (opts->type == REBASE_APPLY) {
1134                 status = run_am(opts);
1135                 goto finished_rebase;
1136         }
1137
1138         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1139         add_var(&script_snippet, "state_dir", opts->state_dir);
1140
1141         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1142         add_var(&script_snippet, "upstream", opts->upstream ?
1143                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1144         add_var(&script_snippet, "head_name",
1145                 opts->head_name ? opts->head_name : "detached HEAD");
1146         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1147         add_var(&script_snippet, "onto", opts->onto ?
1148                 oid_to_hex(&opts->onto->object.oid) : NULL);
1149         add_var(&script_snippet, "onto_name", opts->onto_name);
1150         add_var(&script_snippet, "revisions", opts->revisions);
1151         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1152                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1153         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1154         add_var(&script_snippet, "git_am_opt", buf.buf);
1155         strbuf_release(&buf);
1156         add_var(&script_snippet, "verbose",
1157                 opts->flags & REBASE_VERBOSE ? "t" : "");
1158         add_var(&script_snippet, "diffstat",
1159                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1160         add_var(&script_snippet, "force_rebase",
1161                 opts->flags & REBASE_FORCE ? "t" : "");
1162         if (opts->switch_to)
1163                 add_var(&script_snippet, "switch_to", opts->switch_to);
1164         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1165         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1166         add_var(&script_snippet, "allow_rerere_autoupdate",
1167                 opts->allow_rerere_autoupdate ?
1168                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1169                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1170         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1171         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1172         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1173         add_var(&script_snippet, "cmd", opts->cmd);
1174         add_var(&script_snippet, "allow_empty_message",
1175                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1176         add_var(&script_snippet, "rebase_merges",
1177                 opts->rebase_merges ? "t" : "");
1178         add_var(&script_snippet, "rebase_cousins",
1179                 opts->rebase_cousins ? "t" : "");
1180         add_var(&script_snippet, "strategy", opts->strategy);
1181         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1182         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1183         add_var(&script_snippet, "squash_onto",
1184                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1185         add_var(&script_snippet, "git_format_patch_opt",
1186                 opts->git_format_patch_opt.buf);
1187
1188         if (is_merge(opts) &&
1189             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1190                 strbuf_addstr(&script_snippet,
1191                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1192                 opts->autosquash = 0;
1193         }
1194
1195         switch (opts->type) {
1196         case REBASE_PRESERVE_MERGES:
1197                 backend = "git-rebase--preserve-merges";
1198                 backend_func = "git_rebase__preserve_merges";
1199                 break;
1200         default:
1201                 BUG("Unhandled rebase type %d", opts->type);
1202                 break;
1203         }
1204
1205         strbuf_addf(&script_snippet,
1206                     ". git-sh-setup && . %s && %s", backend, backend_func);
1207         argv[0] = script_snippet.buf;
1208
1209         status = run_command_v_opt(argv, RUN_USING_SHELL);
1210 finished_rebase:
1211         if (opts->dont_finish_rebase)
1212                 ; /* do nothing */
1213         else if (opts->type == REBASE_MERGE)
1214                 ; /* merge backend cleans up after itself */
1215         else if (status == 0) {
1216                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1217                         finish_rebase(opts);
1218         } else if (status == 2) {
1219                 struct strbuf dir = STRBUF_INIT;
1220
1221                 apply_autostash(opts);
1222                 strbuf_addstr(&dir, opts->state_dir);
1223                 remove_dir_recursively(&dir, 0);
1224                 strbuf_release(&dir);
1225                 die("Nothing to do");
1226         }
1227
1228         strbuf_release(&script_snippet);
1229
1230         return status ? -1 : 0;
1231 }
1232
1233 static int rebase_config(const char *var, const char *value, void *data)
1234 {
1235         struct rebase_options *opts = data;
1236
1237         if (!strcmp(var, "rebase.stat")) {
1238                 if (git_config_bool(var, value))
1239                         opts->flags |= REBASE_DIFFSTAT;
1240                 else
1241                         opts->flags &= ~REBASE_DIFFSTAT;
1242                 return 0;
1243         }
1244
1245         if (!strcmp(var, "rebase.autosquash")) {
1246                 opts->autosquash = git_config_bool(var, value);
1247                 return 0;
1248         }
1249
1250         if (!strcmp(var, "commit.gpgsign")) {
1251                 free(opts->gpg_sign_opt);
1252                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1253                         xstrdup("-S") : NULL;
1254                 return 0;
1255         }
1256
1257         if (!strcmp(var, "rebase.autostash")) {
1258                 opts->autostash = git_config_bool(var, value);
1259                 return 0;
1260         }
1261
1262         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1263                 opts->reschedule_failed_exec = git_config_bool(var, value);
1264                 return 0;
1265         }
1266
1267         if (!strcmp(var, "rebase.usebuiltin")) {
1268                 opts->use_legacy_rebase = !git_config_bool(var, value);
1269                 return 0;
1270         }
1271
1272         if (!strcmp(var, "rebase.backend")) {
1273                 return git_config_string(&opts->default_backend, var, value);
1274         }
1275
1276         return git_default_config(var, value, data);
1277 }
1278
1279 /*
1280  * Determines whether the commits in from..to are linear, i.e. contain
1281  * no merge commits. This function *expects* `from` to be an ancestor of
1282  * `to`.
1283  */
1284 static int is_linear_history(struct commit *from, struct commit *to)
1285 {
1286         while (to && to != from) {
1287                 parse_commit(to);
1288                 if (!to->parents)
1289                         return 1;
1290                 if (to->parents->next)
1291                         return 0;
1292                 to = to->parents->item;
1293         }
1294         return 1;
1295 }
1296
1297 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1298                             struct commit *restrict_revision,
1299                             struct object_id *head_oid, struct object_id *merge_base)
1300 {
1301         struct commit *head = lookup_commit(the_repository, head_oid);
1302         struct commit_list *merge_bases = NULL;
1303         int res = 0;
1304
1305         if (!head)
1306                 goto done;
1307
1308         merge_bases = get_merge_bases(onto, head);
1309         if (!merge_bases || merge_bases->next) {
1310                 oidcpy(merge_base, &null_oid);
1311                 goto done;
1312         }
1313
1314         oidcpy(merge_base, &merge_bases->item->object.oid);
1315         if (!oideq(merge_base, &onto->object.oid))
1316                 goto done;
1317
1318         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1319                 goto done;
1320
1321         if (!upstream)
1322                 goto done;
1323
1324         free_commit_list(merge_bases);
1325         merge_bases = get_merge_bases(upstream, head);
1326         if (!merge_bases || merge_bases->next)
1327                 goto done;
1328
1329         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1330                 goto done;
1331
1332         res = 1;
1333
1334 done:
1335         free_commit_list(merge_bases);
1336         return res && is_linear_history(onto, head);
1337 }
1338
1339 static int parse_opt_am(const struct option *opt, const char *arg, int unset)
1340 {
1341         struct rebase_options *opts = opt->value;
1342
1343         BUG_ON_OPT_NEG(unset);
1344         BUG_ON_OPT_ARG(arg);
1345
1346         opts->type = REBASE_APPLY;
1347
1348         return 0;
1349 }
1350
1351 /* -i followed by -m is still -i */
1352 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1353 {
1354         struct rebase_options *opts = opt->value;
1355
1356         BUG_ON_OPT_NEG(unset);
1357         BUG_ON_OPT_ARG(arg);
1358
1359         if (!is_merge(opts))
1360                 opts->type = REBASE_MERGE;
1361
1362         return 0;
1363 }
1364
1365 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1366 static int parse_opt_interactive(const struct option *opt, const char *arg,
1367                                  int unset)
1368 {
1369         struct rebase_options *opts = opt->value;
1370
1371         BUG_ON_OPT_NEG(unset);
1372         BUG_ON_OPT_ARG(arg);
1373
1374         opts->type = REBASE_MERGE;
1375         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1376
1377         return 0;
1378 }
1379
1380 static enum empty_type parse_empty_value(const char *value)
1381 {
1382         if (!strcasecmp(value, "drop"))
1383                 return EMPTY_DROP;
1384         else if (!strcasecmp(value, "keep"))
1385                 return EMPTY_KEEP;
1386         else if (!strcasecmp(value, "ask"))
1387                 return EMPTY_ASK;
1388
1389         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
1390 }
1391
1392 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
1393 {
1394         struct rebase_options *options = opt->value;
1395         enum empty_type value = parse_empty_value(arg);
1396
1397         BUG_ON_OPT_NEG(unset);
1398
1399         options->empty = value;
1400         return 0;
1401 }
1402
1403 static void NORETURN error_on_missing_default_upstream(void)
1404 {
1405         struct branch *current_branch = branch_get(NULL);
1406
1407         printf(_("%s\n"
1408                  "Please specify which branch you want to rebase against.\n"
1409                  "See git-rebase(1) for details.\n"
1410                  "\n"
1411                  "    git rebase '<branch>'\n"
1412                  "\n"),
1413                 current_branch ? _("There is no tracking information for "
1414                         "the current branch.") :
1415                         _("You are not currently on a branch."));
1416
1417         if (current_branch) {
1418                 const char *remote = current_branch->remote_name;
1419
1420                 if (!remote)
1421                         remote = _("<remote>");
1422
1423                 printf(_("If you wish to set tracking information for this "
1424                          "branch you can do so with:\n"
1425                          "\n"
1426                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1427                          "\n"),
1428                        remote, current_branch->name);
1429         }
1430         exit(1);
1431 }
1432
1433 static void set_reflog_action(struct rebase_options *options)
1434 {
1435         const char *env;
1436         struct strbuf buf = STRBUF_INIT;
1437
1438         if (!is_merge(options))
1439                 return;
1440
1441         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1442         if (env && strcmp("rebase", env))
1443                 return; /* only override it if it is "rebase" */
1444
1445         strbuf_addf(&buf, "rebase (%s)", options->action);
1446         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1447         strbuf_release(&buf);
1448 }
1449
1450 static int check_exec_cmd(const char *cmd)
1451 {
1452         if (strchr(cmd, '\n'))
1453                 return error(_("exec commands cannot contain newlines"));
1454
1455         /* Does the command consist purely of whitespace? */
1456         if (!cmd[strspn(cmd, " \t\r\f\v")])
1457                 return error(_("empty exec command"));
1458
1459         return 0;
1460 }
1461
1462
1463 int cmd_rebase(int argc, const char **argv, const char *prefix)
1464 {
1465         struct rebase_options options = REBASE_OPTIONS_INIT;
1466         const char *branch_name;
1467         int ret, flags, total_argc, in_progress = 0;
1468         int keep_base = 0;
1469         int ok_to_skip_pre_rebase = 0;
1470         struct strbuf msg = STRBUF_INIT;
1471         struct strbuf revisions = STRBUF_INIT;
1472         struct strbuf buf = STRBUF_INIT;
1473         struct object_id merge_base;
1474         enum action action = ACTION_NONE;
1475         const char *gpg_sign = NULL;
1476         struct string_list exec = STRING_LIST_INIT_NODUP;
1477         const char *rebase_merges = NULL;
1478         int fork_point = -1;
1479         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1480         struct object_id squash_onto;
1481         char *squash_onto_name = NULL;
1482         int reschedule_failed_exec = -1;
1483         int allow_preemptive_ff = 1;
1484         struct option builtin_rebase_options[] = {
1485                 OPT_STRING(0, "onto", &options.onto_name,
1486                            N_("revision"),
1487                            N_("rebase onto given branch instead of upstream")),
1488                 OPT_BOOL(0, "keep-base", &keep_base,
1489                          N_("use the merge-base of upstream and branch as the current base")),
1490                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1491                          N_("allow pre-rebase hook to run")),
1492                 OPT_NEGBIT('q', "quiet", &options.flags,
1493                            N_("be quiet. implies --no-stat"),
1494                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1495                 OPT_BIT('v', "verbose", &options.flags,
1496                         N_("display a diffstat of what changed upstream"),
1497                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1498                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1499                         N_("do not show diffstat of what changed upstream"),
1500                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1501                 OPT_BOOL(0, "signoff", &options.signoff,
1502                          N_("add a Signed-off-by: line to each commit")),
1503                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1504                                   NULL, N_("passed to 'git am'"),
1505                                   PARSE_OPT_NOARG),
1506                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1507                                   &options.git_am_opts, NULL,
1508                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1509                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1510                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1511                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1512                                   N_("passed to 'git apply'"), 0),
1513                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1514                                   N_("action"), N_("passed to 'git apply'"), 0),
1515                 OPT_BIT('f', "force-rebase", &options.flags,
1516                         N_("cherry-pick all commits, even if unchanged"),
1517                         REBASE_FORCE),
1518                 OPT_BIT(0, "no-ff", &options.flags,
1519                         N_("cherry-pick all commits, even if unchanged"),
1520                         REBASE_FORCE),
1521                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1522                             ACTION_CONTINUE),
1523                 OPT_CMDMODE(0, "skip", &action,
1524                             N_("skip current patch and continue"), ACTION_SKIP),
1525                 OPT_CMDMODE(0, "abort", &action,
1526                             N_("abort and check out the original branch"),
1527                             ACTION_ABORT),
1528                 OPT_CMDMODE(0, "quit", &action,
1529                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1530                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1531                             "during an interactive rebase"), ACTION_EDIT_TODO),
1532                 OPT_CMDMODE(0, "show-current-patch", &action,
1533                             N_("show the patch file being applied or merged"),
1534                             ACTION_SHOW_CURRENT_PATCH),
1535                 { OPTION_CALLBACK, 0, "apply", &options, NULL,
1536                         N_("use apply strategies to rebase"),
1537                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1538                         parse_opt_am },
1539                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1540                         N_("use merging strategies to rebase"),
1541                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1542                         parse_opt_merge },
1543                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1544                         N_("let the user edit the list of commits to rebase"),
1545                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1546                         parse_opt_interactive },
1547                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1548                               N_("(DEPRECATED) try to recreate merges instead of "
1549                                  "ignoring them"),
1550                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1551                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1552                 OPT_CALLBACK_F(0, "empty", &options, "{drop,keep,ask}",
1553                                N_("how to handle commits that become empty"),
1554                                PARSE_OPT_NONEG, parse_opt_empty),
1555                 { OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
1556                         N_("keep commits which start empty"),
1557                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1558                         parse_opt_keep_empty },
1559                 OPT_BOOL(0, "autosquash", &options.autosquash,
1560                          N_("move commits that begin with "
1561                             "squash!/fixup! under -i")),
1562                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1563                         N_("GPG-sign commits"),
1564                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1565                 OPT_BOOL(0, "autostash", &options.autostash,
1566                          N_("automatically stash/stash pop before and after")),
1567                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1568                                 N_("add exec lines after each commit of the "
1569                                    "editable list")),
1570                 OPT_BOOL_F(0, "allow-empty-message",
1571                            &options.allow_empty_message,
1572                            N_("allow rebasing commits with empty messages"),
1573                            PARSE_OPT_HIDDEN),
1574                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1575                         N_("mode"),
1576                         N_("try to rebase merges instead of skipping them"),
1577                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1578                 OPT_BOOL(0, "fork-point", &fork_point,
1579                          N_("use 'merge-base --fork-point' to refine upstream")),
1580                 OPT_STRING('s', "strategy", &options.strategy,
1581                            N_("strategy"), N_("use the given merge strategy")),
1582                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1583                                 N_("option"),
1584                                 N_("pass the argument through to the merge "
1585                                    "strategy")),
1586                 OPT_BOOL(0, "root", &options.root,
1587                          N_("rebase all reachable commits up to the root(s)")),
1588                 OPT_BOOL(0, "reschedule-failed-exec",
1589                          &reschedule_failed_exec,
1590                          N_("automatically re-schedule any `exec` that fails")),
1591                 OPT_BOOL(0, "reapply-cherry-picks", &options.reapply_cherry_picks,
1592                          N_("apply all changes, even those already present upstream")),
1593                 OPT_END(),
1594         };
1595         int i;
1596
1597         if (argc == 2 && !strcmp(argv[1], "-h"))
1598                 usage_with_options(builtin_rebase_usage,
1599                                    builtin_rebase_options);
1600
1601         options.allow_empty_message = 1;
1602         git_config(rebase_config, &options);
1603         /* options.gpg_sign_opt will be either "-S" or NULL */
1604         gpg_sign = options.gpg_sign_opt ? "" : NULL;
1605         FREE_AND_NULL(options.gpg_sign_opt);
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_APPLY;
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_MERGE;
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_merge(&options))
1671                 die(_("The --edit-todo action can only be used during "
1672                       "interactive rebase."));
1673
1674         if (trace2_is_enabled()) {
1675                 if (is_merge(&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_MERGE) {
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_merge(&options, "--empty");
1835
1836         if (options.reapply_cherry_picks)
1837                 imply_merge(&options, "--reapply-cherry-picks");
1838
1839         if (gpg_sign)
1840                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1841
1842         if (exec.nr) {
1843                 int i;
1844
1845                 imply_merge(&options, "--exec");
1846
1847                 strbuf_reset(&buf);
1848                 for (i = 0; i < exec.nr; i++)
1849                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1850                 options.cmd = xstrdup(buf.buf);
1851         }
1852
1853         if (rebase_merges) {
1854                 if (!*rebase_merges)
1855                         ; /* default mode; do nothing */
1856                 else if (!strcmp("rebase-cousins", rebase_merges))
1857                         options.rebase_cousins = 1;
1858                 else if (strcmp("no-rebase-cousins", rebase_merges))
1859                         die(_("Unknown mode: %s"), rebase_merges);
1860                 options.rebase_merges = 1;
1861                 imply_merge(&options, "--rebase-merges");
1862         }
1863
1864         if (strategy_options.nr) {
1865                 int i;
1866
1867                 if (!options.strategy)
1868                         options.strategy = "recursive";
1869
1870                 strbuf_reset(&buf);
1871                 for (i = 0; i < strategy_options.nr; i++)
1872                         strbuf_addf(&buf, " --%s",
1873                                     strategy_options.items[i].string);
1874                 options.strategy_opts = xstrdup(buf.buf);
1875         }
1876
1877         if (options.strategy) {
1878                 options.strategy = xstrdup(options.strategy);
1879                 switch (options.type) {
1880                 case REBASE_APPLY:
1881                         die(_("--strategy requires --merge or --interactive"));
1882                 case REBASE_MERGE:
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_merge(&options, "--merge");
1896
1897         if (options.root && !options.onto_name)
1898                 imply_merge(&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_APPLY) {
1904                 /* all am options except -q are compatible only with --apply */
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_merge(&options))
1911                                 die(_("cannot combine apply options with "
1912                                       "merge options"));
1913                         else
1914                                 options.type = REBASE_APPLY;
1915                 }
1916         }
1917
1918         if (options.type == REBASE_UNSPECIFIED) {
1919                 if (!strcmp(options.default_backend, "merge"))
1920                         imply_merge(&options, "--merge");
1921                 else if (!strcmp(options.default_backend, "apply"))
1922                         options.type = REBASE_APPLY;
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_PRESERVE_MERGES:
1931                 options.state_dir = merge_dir();
1932                 break;
1933         case REBASE_APPLY:
1934                 options.state_dir = apply_dir();
1935                 break;
1936         default:
1937                 BUG("options.type was just set above; should be unreachable.");
1938         }
1939
1940         if (options.empty == EMPTY_UNSPECIFIED) {
1941                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1942                         options.empty = EMPTY_ASK;
1943                 else if (exec.nr > 0)
1944                         options.empty = EMPTY_KEEP;
1945                 else
1946                         options.empty = EMPTY_DROP;
1947         }
1948         if (reschedule_failed_exec > 0 && !is_merge(&options))
1949                 die(_("--reschedule-failed-exec requires "
1950                       "--exec or --interactive"));
1951         if (reschedule_failed_exec >= 0)
1952                 options.reschedule_failed_exec = reschedule_failed_exec;
1953
1954         if (options.signoff) {
1955                 if (options.type == REBASE_PRESERVE_MERGES)
1956                         die("cannot combine '--signoff' with "
1957                             "'--preserve-merges'");
1958                 argv_array_push(&options.git_am_opts, "--signoff");
1959                 options.flags |= REBASE_FORCE;
1960         }
1961
1962         if (options.type == REBASE_PRESERVE_MERGES) {
1963                 /*
1964                  * Note: incompatibility with --signoff handled in signoff block above
1965                  * Note: incompatibility with --interactive is just a strong warning;
1966                  *       git-rebase.txt caveats with "unless you know what you are doing"
1967                  */
1968                 if (options.rebase_merges)
1969                         die(_("cannot combine '--preserve-merges' with "
1970                               "'--rebase-merges'"));
1971
1972                 if (options.reschedule_failed_exec)
1973                         die(_("error: cannot combine '--preserve-merges' with "
1974                               "'--reschedule-failed-exec'"));
1975         }
1976
1977         if (!options.root) {
1978                 if (argc < 1) {
1979                         struct branch *branch;
1980
1981                         branch = branch_get(NULL);
1982                         options.upstream_name = branch_get_upstream(branch,
1983                                                                     NULL);
1984                         if (!options.upstream_name)
1985                                 error_on_missing_default_upstream();
1986                         if (fork_point < 0)
1987                                 fork_point = 1;
1988                 } else {
1989                         options.upstream_name = argv[0];
1990                         argc--;
1991                         argv++;
1992                         if (!strcmp(options.upstream_name, "-"))
1993                                 options.upstream_name = "@{-1}";
1994                 }
1995                 options.upstream = peel_committish(options.upstream_name);
1996                 if (!options.upstream)
1997                         die(_("invalid upstream '%s'"), options.upstream_name);
1998                 options.upstream_arg = options.upstream_name;
1999         } else {
2000                 if (!options.onto_name) {
2001                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
2002                                         &squash_onto, NULL, NULL) < 0)
2003                                 die(_("Could not create new root commit"));
2004                         options.squash_onto = &squash_onto;
2005                         options.onto_name = squash_onto_name =
2006                                 xstrdup(oid_to_hex(&squash_onto));
2007                 } else
2008                         options.root_with_onto = 1;
2009
2010                 options.upstream_name = NULL;
2011                 options.upstream = NULL;
2012                 if (argc > 1)
2013                         usage_with_options(builtin_rebase_usage,
2014                                            builtin_rebase_options);
2015                 options.upstream_arg = "--root";
2016         }
2017
2018         /* Make sure the branch to rebase onto is valid. */
2019         if (keep_base) {
2020                 strbuf_reset(&buf);
2021                 strbuf_addstr(&buf, options.upstream_name);
2022                 strbuf_addstr(&buf, "...");
2023                 options.onto_name = xstrdup(buf.buf);
2024         } else if (!options.onto_name)
2025                 options.onto_name = options.upstream_name;
2026         if (strstr(options.onto_name, "...")) {
2027                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
2028                         if (keep_base)
2029                                 die(_("'%s': need exactly one merge base with branch"),
2030                                     options.upstream_name);
2031                         else
2032                                 die(_("'%s': need exactly one merge base"),
2033                                     options.onto_name);
2034                 }
2035                 options.onto = lookup_commit_or_die(&merge_base,
2036                                                     options.onto_name);
2037         } else {
2038                 options.onto = peel_committish(options.onto_name);
2039                 if (!options.onto)
2040                         die(_("Does not point to a valid commit '%s'"),
2041                                 options.onto_name);
2042         }
2043
2044         /*
2045          * If the branch to rebase is given, that is the branch we will rebase
2046          * branch_name -- branch/commit being rebased, or
2047          *                HEAD (already detached)
2048          * orig_head -- commit object name of tip of the branch before rebasing
2049          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
2050          */
2051         if (argc == 1) {
2052                 /* Is it "rebase other branchname" or "rebase other commit"? */
2053                 branch_name = argv[0];
2054                 options.switch_to = argv[0];
2055
2056                 /* Is it a local branch? */
2057                 strbuf_reset(&buf);
2058                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
2059                 if (!read_ref(buf.buf, &options.orig_head)) {
2060                         die_if_checked_out(buf.buf, 1);
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                                 strbuf_reset(&buf);
2174                                 strbuf_addf(&buf, "%s: checkout %s",
2175                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2176                                             options.switch_to);
2177                                 if (reset_head(&options.orig_head, "checkout",
2178                                                options.head_name,
2179                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2180                                                NULL, buf.buf) < 0) {
2181                                         ret = !!error(_("could not switch to "
2182                                                         "%s"),
2183                                                       options.switch_to);
2184                                         goto cleanup;
2185                                 }
2186                         }
2187
2188                         if (!(options.flags & REBASE_NO_QUIET))
2189                                 ; /* be quiet */
2190                         else if (!strcmp(branch_name, "HEAD") &&
2191                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2192                                 puts(_("HEAD is up to date."));
2193                         else
2194                                 printf(_("Current branch %s is up to date.\n"),
2195                                        branch_name);
2196                         ret = !!finish_rebase(&options);
2197                         goto cleanup;
2198                 } else if (!(options.flags & REBASE_NO_QUIET))
2199                         ; /* be quiet */
2200                 else if (!strcmp(branch_name, "HEAD") &&
2201                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2202                         puts(_("HEAD is up to date, rebase forced."));
2203                 else
2204                         printf(_("Current branch %s is up to date, rebase "
2205                                  "forced.\n"), branch_name);
2206         }
2207
2208         /* If a hook exists, give it a chance to interrupt*/
2209         if (!ok_to_skip_pre_rebase &&
2210             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2211                         argc ? argv[0] : NULL, NULL))
2212                 die(_("The pre-rebase hook refused to rebase."));
2213
2214         if (options.flags & REBASE_DIFFSTAT) {
2215                 struct diff_options opts;
2216
2217                 if (options.flags & REBASE_VERBOSE) {
2218                         if (is_null_oid(&merge_base))
2219                                 printf(_("Changes to %s:\n"),
2220                                        oid_to_hex(&options.onto->object.oid));
2221                         else
2222                                 printf(_("Changes from %s to %s:\n"),
2223                                        oid_to_hex(&merge_base),
2224                                        oid_to_hex(&options.onto->object.oid));
2225                 }
2226
2227                 /* We want color (if set), but no pager */
2228                 diff_setup(&opts);
2229                 opts.stat_width = -1; /* use full terminal width */
2230                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2231                 opts.output_format |=
2232                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2233                 opts.detect_rename = DIFF_DETECT_RENAME;
2234                 diff_setup_done(&opts);
2235                 diff_tree_oid(is_null_oid(&merge_base) ?
2236                               the_hash_algo->empty_tree : &merge_base,
2237                               &options.onto->object.oid, "", &opts);
2238                 diffcore_std(&opts);
2239                 diff_flush(&opts);
2240         }
2241
2242         if (is_merge(&options))
2243                 goto run_rebase;
2244
2245         /* Detach HEAD and reset the tree */
2246         if (options.flags & REBASE_NO_QUIET)
2247                 printf(_("First, rewinding head to replay your work on top of "
2248                          "it...\n"));
2249
2250         strbuf_addf(&msg, "%s: checkout %s",
2251                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2252         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2253                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2254                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2255                        NULL, msg.buf))
2256                 die(_("Could not detach HEAD"));
2257         strbuf_release(&msg);
2258
2259         /*
2260          * If the onto is a proper descendant of the tip of the branch, then
2261          * we just fast-forwarded.
2262          */
2263         strbuf_reset(&msg);
2264         if (oideq(&merge_base, &options.orig_head)) {
2265                 printf(_("Fast-forwarded %s to %s.\n"),
2266                         branch_name, options.onto_name);
2267                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2268                         options.head_name ? options.head_name : "detached HEAD",
2269                         oid_to_hex(&options.onto->object.oid));
2270                 reset_head(NULL, "Fast-forwarded", options.head_name,
2271                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2272                 strbuf_release(&msg);
2273                 ret = !!finish_rebase(&options);
2274                 goto cleanup;
2275         }
2276
2277         strbuf_addf(&revisions, "%s..%s",
2278                     options.root ? oid_to_hex(&options.onto->object.oid) :
2279                     (options.restrict_revision ?
2280                      oid_to_hex(&options.restrict_revision->object.oid) :
2281                      oid_to_hex(&options.upstream->object.oid)),
2282                     oid_to_hex(&options.orig_head));
2283
2284         options.revisions = revisions.buf;
2285
2286 run_rebase:
2287         ret = !!run_specific_rebase(&options, action);
2288
2289 cleanup:
2290         strbuf_release(&buf);
2291         strbuf_release(&revisions);
2292         free(options.head_name);
2293         free(options.gpg_sign_opt);
2294         free(options.cmd);
2295         free(squash_onto_name);
2296         return ret;
2297 }