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