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