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

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   8 #include "builtin.h"
   9 #include "run-command.h"
  10 #include "exec-cmd.h"
  11 #include "argv-array.h"
  12 #include "dir.h"
  13 #include "packfile.h"
  14 #include "refs.h"
  15 #include "quote.h"
  16 #include "config.h"
  17 #include "cache-tree.h"
  18 #include "unpack-trees.h"
  19 #include "lockfile.h"
  20 #include "parse-options.h"
  21 #include "commit.h"
  22 #include "diff.h"
  23 #include "wt-status.h"
  24 #include "revision.h"
  25 #include "commit-reach.h"
  26 #include "rerere.h"
  27 #include "branch.h"
  28 #include "sequencer.h"
  29 #include "rebase-interactive.h"
  30
  31 static char const * const builtin_rebase_usage[] = {
  32         N_("git rebase [-i] [options] [--exec <cmd>] "
  33                 "[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
  34         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  35                 "--root [<branch>]"),
  36         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  37         NULL
  38 };
  39
  40 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
  41 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
  42 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  43 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  44
  45 enum rebase_type {
  46         REBASE_UNSPECIFIED = -1,
  47         REBASE_AM,
  48         REBASE_MERGE,
  49         REBASE_INTERACTIVE,
  50         REBASE_PRESERVE_MERGES
  51 };
  52
  53 struct rebase_options {
  54         enum rebase_type type;
  55         const char *state_dir;
  56         struct commit *upstream;
  57         const char *upstream_name;
  58         const char *upstream_arg;
  59         char *head_name;
  60         struct object_id orig_head;
  61         struct commit *onto;
  62         const char *onto_name;
  63         const char *revisions;
  64         const char *switch_to;
  65         int root, root_with_onto;
  66         struct object_id *squash_onto;
  67         struct commit *restrict_revision;
  68         int dont_finish_rebase;
  69         enum {
  70                 REBASE_NO_QUIET = 1<<0,
  71                 REBASE_VERBOSE = 1<<1,
  72                 REBASE_DIFFSTAT = 1<<2,
  73                 REBASE_FORCE = 1<<3,
  74                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  75         } flags;
  76         struct argv_array git_am_opts;
  77         const char *action;
  78         int signoff;
  79         int allow_rerere_autoupdate;
  80         int keep_empty;
  81         int autosquash;
  82         int ignore_whitespace;
  83         char *gpg_sign_opt;
  84         int autostash;
  85         int committer_date_is_author_date;
  86         int ignore_date;
  87         char *cmd;
  88         int allow_empty_message;
  89         int rebase_merges, rebase_cousins;
  90         char *strategy, *strategy_opts;
  91         struct strbuf git_format_patch_opt;
  92         int reschedule_failed_exec;
  93         int use_legacy_rebase;
  94 };
  95
  96 #define REBASE_OPTIONS_INIT {                           \
  97                 .type = REBASE_UNSPECIFIED,             \
  98                 .flags = REBASE_NO_QUIET,               \
  99                 .git_am_opts = ARGV_ARRAY_INIT,         \
 100                 .git_format_patch_opt = STRBUF_INIT     \
 101         }
 102
 103 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 104 {
 105         struct strbuf strategy_buf = STRBUF_INIT;
 106         struct replay_opts replay = REPLAY_OPTS_INIT;
 107
 108         replay.action = REPLAY_INTERACTIVE_REBASE;
 109         sequencer_init_config(&replay);
 110
 111         replay.signoff = opts->signoff;
 112         replay.allow_ff = !(opts->flags & REBASE_FORCE);
 113         if (opts->allow_rerere_autoupdate)
 114                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 115         replay.allow_empty = 1;
 116         replay.allow_empty_message = opts->allow_empty_message;
 117         replay.verbose = opts->flags & REBASE_VERBOSE;
 118         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 119         replay.committer_date_is_author_date =
 120                                         opts->committer_date_is_author_date;
 121         replay.ignore_date = opts->ignore_date;
 122         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 123         replay.strategy = opts->strategy;
 124
 125         if (opts->strategy_opts)
 126                 strbuf_addstr(&strategy_buf, opts->strategy_opts);
 127         if (opts->ignore_whitespace)
 128                 strbuf_addstr(&strategy_buf, " --ignore-space-change");
 129         if (strategy_buf.len)
 130                 parse_strategy_opts(&replay, strategy_buf.buf);
 131
 132         strbuf_release(&strategy_buf);
 133
 134         if (opts->squash_onto) {
 135                 oidcpy(&replay.squash_onto, opts->squash_onto);
 136                 replay.have_squash_onto = 1;
 137         }
 138
 139         return replay;
 140 }
 141
 142 enum action {
 143         ACTION_NONE = 0,
 144         ACTION_CONTINUE,
 145         ACTION_SKIP,
 146         ACTION_ABORT,
 147         ACTION_QUIT,
 148         ACTION_EDIT_TODO,
 149         ACTION_SHOW_CURRENT_PATCH,
 150         ACTION_SHORTEN_OIDS,
 151         ACTION_EXPAND_OIDS,
 152         ACTION_CHECK_TODO_LIST,
 153         ACTION_REARRANGE_SQUASH,
 154         ACTION_ADD_EXEC
 155 };
 156
 157 static const char *action_names[] = { "undefined",
 158                                       "continue",
 159                                       "skip",
 160                                       "abort",
 161                                       "quit",
 162                                       "edit_todo",
 163                                       "show_current_patch" };
 164
 165 static int add_exec_commands(struct string_list *commands)
 166 {
 167         const char *todo_file = rebase_path_todo();
 168         struct todo_list todo_list = TODO_LIST_INIT;
 169         int res;
 170
 171         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 172                 return error_errno(_("could not read '%s'."), todo_file);
 173
 174         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 175                                         &todo_list)) {
 176                 todo_list_release(&todo_list);
 177                 return error(_("unusable todo list: '%s'"), todo_file);
 178         }
 179
 180         todo_list_add_exec_commands(&todo_list, commands);
 181         res = todo_list_write_to_file(the_repository, &todo_list,
 182                                       todo_file, NULL, NULL, -1, 0);
 183         todo_list_release(&todo_list);
 184
 185         if (res)
 186                 return error_errno(_("could not write '%s'."), todo_file);
 187         return 0;
 188 }
 189
 190 static int rearrange_squash_in_todo_file(void)
 191 {
 192         const char *todo_file = rebase_path_todo();
 193         struct todo_list todo_list = TODO_LIST_INIT;
 194         int res = 0;
 195
 196         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 197                 return error_errno(_("could not read '%s'."), todo_file);
 198         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 199                                         &todo_list)) {
 200                 todo_list_release(&todo_list);
 201                 return error(_("unusable todo list: '%s'"), todo_file);
 202         }
 203
 204         res = todo_list_rearrange_squash(&todo_list);
 205         if (!res)
 206                 res = todo_list_write_to_file(the_repository, &todo_list,
 207                                               todo_file, NULL, NULL, -1, 0);
 208
 209         todo_list_release(&todo_list);
 210
 211         if (res)
 212                 return error_errno(_("could not write '%s'."), todo_file);
 213         return 0;
 214 }
 215
 216 static int transform_todo_file(unsigned flags)
 217 {
 218         const char *todo_file = rebase_path_todo();
 219         struct todo_list todo_list = TODO_LIST_INIT;
 220         int res;
 221
 222         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 223                 return error_errno(_("could not read '%s'."), todo_file);
 224
 225         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 226                                         &todo_list)) {
 227                 todo_list_release(&todo_list);
 228                 return error(_("unusable todo list: '%s'"), todo_file);
 229         }
 230
 231         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 232                                       NULL, NULL, -1, flags);
 233         todo_list_release(&todo_list);
 234
 235         if (res)
 236                 return error_errno(_("could not write '%s'."), todo_file);
 237         return 0;
 238 }
 239
 240 static int edit_todo_file(unsigned flags)
 241 {
 242         const char *todo_file = rebase_path_todo();
 243         struct todo_list todo_list = TODO_LIST_INIT,
 244                 new_todo = TODO_LIST_INIT;
 245         int res = 0;
 246
 247         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 248                 return error_errno(_("could not read '%s'."), todo_file);
 249
 250         strbuf_stripspace(&todo_list.buf, 1);
 251         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 252         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 253                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 254                 res = error_errno(_("could not write '%s'"), todo_file);
 255
 256         todo_list_release(&todo_list);
 257         todo_list_release(&new_todo);
 258
 259         return res;
 260 }
 261
 262 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 263                                const char **head_hash,
 264                                char **revisions, char **shortrevisions)
 265 {
 266         struct commit *base_rev = upstream ? upstream : onto;
 267         const char *shorthead;
 268         struct object_id orig_head;
 269
 270         if (get_oid("HEAD", &orig_head))
 271                 return error(_("no HEAD?"));
 272
 273         *head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
 274         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 275                                                    *head_hash);
 276
 277         shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
 278
 279         if (upstream) {
 280                 const char *shortrev;
 281
 282                 shortrev = find_unique_abbrev(&base_rev->object.oid,
 283                                               DEFAULT_ABBREV);
 284
 285                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 286         } else
 287                 *shortrevisions = xstrdup(shorthead);
 288
 289         return 0;
 290 }
 291
 292 static int init_basic_state(struct replay_opts *opts, const char *head_name,
 293                             struct commit *onto, const char *orig_head)
 294 {
 295         FILE *interactive;
 296
 297         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 298                 return error_errno(_("could not create temporary %s"), merge_dir());
 299
 300         delete_reflog("REBASE_HEAD");
 301
 302         interactive = fopen(path_interactive(), "w");
 303         if (!interactive)
 304                 return error_errno(_("could not mark as interactive"));
 305         fclose(interactive);
 306
 307         return write_basic_state(opts, head_name, onto, orig_head);
 308 }
 309
 310 static void split_exec_commands(const char *cmd, struct string_list *commands)
 311 {
 312         if (cmd && *cmd) {
 313                 string_list_split(commands, cmd, '\n', -1);
 314
 315                 /* rebase.c adds a new line to cmd after every command,
 316                  * so here the last command is always empty */
 317                 string_list_remove_empty_items(commands, 0);
 318         }
 319 }
 320
 321 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 322 {
 323         int ret;
 324         const char *head_hash = NULL;
 325         char *revisions = NULL, *shortrevisions = NULL;
 326         struct argv_array make_script_args = ARGV_ARRAY_INIT;
 327         struct todo_list todo_list = TODO_LIST_INIT;
 328         struct replay_opts replay = get_replay_opts(opts);
 329         struct string_list commands = STRING_LIST_INIT_DUP;
 330
 331         if (prepare_branch_to_be_rebased(the_repository, &replay,
 332                                          opts->switch_to))
 333                 return -1;
 334
 335         if (get_revision_ranges(opts->upstream, opts->onto, &head_hash,
 336                                 &revisions, &shortrevisions))
 337                 return -1;
 338
 339         if (init_basic_state(&replay,
 340                              opts->head_name ? opts->head_name : "detached HEAD",
 341                              opts->onto, head_hash)) {
 342                 free(revisions);
 343                 free(shortrevisions);
 344
 345                 return -1;
 346         }
 347
 348         if (!opts->upstream && opts->squash_onto)
 349                 write_file(path_squash_onto(), "%s\n",
 350                            oid_to_hex(opts->squash_onto));
 351
 352         argv_array_pushl(&make_script_args, "", revisions, NULL);
 353         if (opts->restrict_revision)
 354                 argv_array_push(&make_script_args,
 355                                 oid_to_hex(&opts->restrict_revision->object.oid));
 356
 357         ret = sequencer_make_script(the_repository, &todo_list.buf,
 358                                     make_script_args.argc, make_script_args.argv,
 359                                     flags);
 360
 361         if (ret)
 362                 error(_("could not generate todo list"));
 363         else {
 364                 discard_cache();
 365                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 366                                                 &todo_list))
 367                         BUG("unusable todo list");
 368
 369                 split_exec_commands(opts->cmd, &commands);
 370                 ret = complete_action(the_repository, &replay, flags,
 371                         shortrevisions, opts->onto_name, opts->onto, head_hash,
 372                         &commands, opts->autosquash, &todo_list);
 373         }
 374
 375         string_list_clear(&commands, 0);
 376         free(revisions);
 377         free(shortrevisions);
 378         todo_list_release(&todo_list);
 379         argv_array_clear(&make_script_args);
 380
 381         return ret;
 382 }
 383
 384 static int run_rebase_interactive(struct rebase_options *opts,
 385                                   enum action command)
 386 {
 387         unsigned flags = 0;
 388         int abbreviate_commands = 0, ret = 0;
 389
 390         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 391
 392         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 393         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 394         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 395         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 396         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 397         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 398
 399         switch (command) {
 400         case ACTION_NONE: {
 401                 if (!opts->onto && !opts->upstream)
 402                         die(_("a base commit must be provided with --upstream or --onto"));
 403
 404                 ret = do_interactive_rebase(opts, flags);
 405                 break;
 406         }
 407         case ACTION_SKIP: {
 408                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 409
 410                 rerere_clear(the_repository, &merge_rr);
 411         }
 412                 /* fallthrough */
 413         case ACTION_CONTINUE: {
 414                 struct replay_opts replay_opts = get_replay_opts(opts);
 415
 416                 ret = sequencer_continue(the_repository, &replay_opts);
 417                 break;
 418         }
 419         case ACTION_EDIT_TODO:
 420                 ret = edit_todo_file(flags);
 421                 break;
 422         case ACTION_SHOW_CURRENT_PATCH: {
 423                 struct child_process cmd = CHILD_PROCESS_INIT;
 424
 425                 cmd.git_cmd = 1;
 426                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 427                 ret = run_command(&cmd);
 428
 429                 break;
 430         }
 431         case ACTION_SHORTEN_OIDS:
 432         case ACTION_EXPAND_OIDS:
 433                 ret = transform_todo_file(flags);
 434                 break;
 435         case ACTION_CHECK_TODO_LIST:
 436                 ret = check_todo_list_from_file(the_repository);
 437                 break;
 438         case ACTION_REARRANGE_SQUASH:
 439                 ret = rearrange_squash_in_todo_file();
 440                 break;
 441         case ACTION_ADD_EXEC: {
 442                 struct string_list commands = STRING_LIST_INIT_DUP;
 443
 444                 split_exec_commands(opts->cmd, &commands);
 445                 ret = add_exec_commands(&commands);
 446                 string_list_clear(&commands, 0);
 447                 break;
 448         }
 449         default:
 450                 BUG("invalid command '%d'", command);
 451         }
 452
 453         return ret;
 454 }
 455
 456 static const char * const builtin_rebase_interactive_usage[] = {
 457         N_("git rebase--interactive [<options>]"),
 458         NULL
 459 };
 460
 461 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 462 {
 463         struct rebase_options opts = REBASE_OPTIONS_INIT;
 464         struct object_id squash_onto = null_oid;
 465         enum action command = ACTION_NONE;
 466         struct option options[] = {
 467                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 468                            REBASE_FORCE),
 469                 OPT_BOOL(0, "keep-empty", &opts.keep_empty, N_("keep empty commits")),
 470                 OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
 471                          N_("allow commits with empty messages")),
 472                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 473                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 474                          N_("keep original branch points of cousins")),
 475                 OPT_BOOL(0, "autosquash", &opts.autosquash,
 476                          N_("move commits that begin with squash!/fixup!")),
 477                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 478                 OPT_BIT('v', "verbose", &opts.flags,
 479                         N_("display a diffstat of what changed upstream"),
 480                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 481                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 482                             ACTION_CONTINUE),
 483                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 484                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 485                             ACTION_EDIT_TODO),
 486                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 487                             ACTION_SHOW_CURRENT_PATCH),
 488                 OPT_CMDMODE(0, "shorten-ids", &command,
 489                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 490                 OPT_CMDMODE(0, "expand-ids", &command,
 491                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 492                 OPT_CMDMODE(0, "check-todo-list", &command,
 493                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 494                 OPT_CMDMODE(0, "rearrange-squash", &command,
 495                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 496                 OPT_CMDMODE(0, "add-exec-commands", &command,
 497                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 498                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 499                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 500                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 501                   N_("restrict-revision"), N_("restrict revision"),
 502                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
 503                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 504                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 505                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 506                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 507                   0 },
 508                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 509                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 510                         N_("GPG-sign commits"),
 511                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 512                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 513                            N_("rebase strategy")),
 514                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 515                            N_("strategy options")),
 516                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 517                            N_("the branch or commit to checkout")),
 518                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 519                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 520                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 521                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 522                          N_("automatically re-schedule any `exec` that fails")),
 523                 OPT_END()
 524         };
 525
 526         opts.rebase_cousins = -1;
 527
 528         if (argc == 1)
 529                 usage_with_options(builtin_rebase_interactive_usage, options);
 530
 531         argc = parse_options(argc, argv, prefix, options,
 532                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 533
 534         opts.strategy_opts = xstrdup_or_null(opts.strategy_opts);
 535
 536         if (!is_null_oid(&squash_onto))
 537                 opts.squash_onto = &squash_onto;
 538
 539         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 540                 warning(_("--[no-]rebase-cousins has no effect without "
 541                           "--rebase-merges"));
 542
 543         return !!run_rebase_interactive(&opts, command);
 544 }
 545
 546 static int is_interactive(struct rebase_options *opts)
 547 {
 548         return opts->type == REBASE_INTERACTIVE ||
 549                 opts->type == REBASE_PRESERVE_MERGES;
 550 }
 551
 552 static void imply_interactive(struct rebase_options *opts, const char *option)
 553 {
 554         switch (opts->type) {
 555         case REBASE_AM:
 556                 die(_("%s requires an interactive rebase"), option);
 557                 break;
 558         case REBASE_INTERACTIVE:
 559         case REBASE_PRESERVE_MERGES:
 560                 break;
 561         case REBASE_MERGE:
 562                 /* we now implement --merge via --interactive */
 563         default:
 564                 opts->type = REBASE_INTERACTIVE; /* implied */
 565                 break;
 566         }
 567 }
 568
 569 /* Returns the filename prefixed by the state_dir */
 570 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 571 {
 572         static struct strbuf path = STRBUF_INIT;
 573         static size_t prefix_len;
 574
 575         if (!prefix_len) {
 576                 strbuf_addf(&path, "%s/", opts->state_dir);
 577                 prefix_len = path.len;
 578         }
 579
 580         strbuf_setlen(&path, prefix_len);
 581         strbuf_addstr(&path, filename);
 582         return path.buf;
 583 }
 584
 585 /* Read one file, then strip line endings */
 586 static int read_one(const char *path, struct strbuf *buf)
 587 {
 588         if (strbuf_read_file(buf, path, 0) < 0)
 589                 return error_errno(_("could not read '%s'"), path);
 590         strbuf_trim_trailing_newline(buf);
 591         return 0;
 592 }
 593
 594 /* Initialize the rebase options from the state directory. */
 595 static int read_basic_state(struct rebase_options *opts)
 596 {
 597         struct strbuf head_name = STRBUF_INIT;
 598         struct strbuf buf = STRBUF_INIT;
 599         struct object_id oid;
 600
 601         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 602             read_one(state_dir_path("onto", opts), &buf))
 603                 return -1;
 604         opts->head_name = starts_with(head_name.buf, "refs/") ?
 605                 xstrdup(head_name.buf) : NULL;
 606         strbuf_release(&head_name);
 607         if (get_oid(buf.buf, &oid))
 608                 return error(_("could not get 'onto': '%s'"), buf.buf);
 609         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 610
 611         /*
 612          * We always write to orig-head, but interactive rebase used to write to
 613          * head. Fall back to reading from head to cover for the case that the
 614          * user upgraded git with an ongoing interactive rebase.
 615          */
 616         strbuf_reset(&buf);
 617         if (file_exists(state_dir_path("orig-head", opts))) {
 618                 if (read_one(state_dir_path("orig-head", opts), &buf))
 619                         return -1;
 620         } else if (read_one(state_dir_path("head", opts), &buf))
 621                 return -1;
 622         if (get_oid(buf.buf, &opts->orig_head))
 623                 return error(_("invalid orig-head: '%s'"), buf.buf);
 624
 625         if (file_exists(state_dir_path("quiet", opts)))
 626                 opts->flags &= ~REBASE_NO_QUIET;
 627         else
 628                 opts->flags |= REBASE_NO_QUIET;
 629
 630         if (file_exists(state_dir_path("verbose", opts)))
 631                 opts->flags |= REBASE_VERBOSE;
 632
 633         if (file_exists(state_dir_path("signoff", opts))) {
 634                 opts->signoff = 1;
 635                 opts->flags |= REBASE_FORCE;
 636         }
 637
 638         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 639                 strbuf_reset(&buf);
 640                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 641                             &buf))
 642                         return -1;
 643                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 644                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 645                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 646                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 647                 else
 648                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 649                                   "'%s'"), buf.buf);
 650         }
 651
 652         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 653                 strbuf_reset(&buf);
 654                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 655                             &buf))
 656                         return -1;
 657                 free(opts->gpg_sign_opt);
 658                 opts->gpg_sign_opt = xstrdup(buf.buf);
 659         }
 660
 661         if (file_exists(state_dir_path("strategy", opts))) {
 662                 strbuf_reset(&buf);
 663                 if (read_one(state_dir_path("strategy", opts), &buf))
 664                         return -1;
 665                 free(opts->strategy);
 666                 opts->strategy = xstrdup(buf.buf);
 667         }
 668
 669         if (file_exists(state_dir_path("strategy_opts", opts))) {
 670                 strbuf_reset(&buf);
 671                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 672                         return -1;
 673                 free(opts->strategy_opts);
 674                 opts->strategy_opts = xstrdup(buf.buf);
 675         }
 676
 677         strbuf_release(&buf);
 678
 679         return 0;
 680 }
 681
 682 static int rebase_write_basic_state(struct rebase_options *opts)
 683 {
 684         write_file(state_dir_path("head-name", opts), "%s",
 685                    opts->head_name ? opts->head_name : "detached HEAD");
 686         write_file(state_dir_path("onto", opts), "%s",
 687                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 688         write_file(state_dir_path("orig-head", opts), "%s",
 689                    oid_to_hex(&opts->orig_head));
 690         write_file(state_dir_path("quiet", opts), "%s",
 691                    opts->flags & REBASE_NO_QUIET ? "" : "t");
 692         if (opts->flags & REBASE_VERBOSE)
 693                 write_file(state_dir_path("verbose", opts), "%s", "");
 694         if (opts->strategy)
 695                 write_file(state_dir_path("strategy", opts), "%s",
 696                            opts->strategy);
 697         if (opts->strategy_opts)
 698                 write_file(state_dir_path("strategy_opts", opts), "%s",
 699                            opts->strategy_opts);
 700         if (opts->allow_rerere_autoupdate > 0)
 701                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
 702                            "-%s-rerere-autoupdate",
 703                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 704                                 "" : "-no");
 705         if (opts->gpg_sign_opt)
 706                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 707                            opts->gpg_sign_opt);
 708         if (opts->signoff)
 709                 write_file(state_dir_path("strategy", opts), "--signoff");
 710
 711         return 0;
 712 }
 713
 714 static int apply_autostash(struct rebase_options *opts)
 715 {
 716         const char *path = state_dir_path("autostash", opts);
 717         struct strbuf autostash = STRBUF_INIT;
 718         struct child_process stash_apply = CHILD_PROCESS_INIT;
 719
 720         if (!file_exists(path))
 721                 return 0;
 722
 723         if (read_one(path, &autostash))
 724                 return error(_("Could not read '%s'"), path);
 725         /* Ensure that the hash is not mistaken for a number */
 726         strbuf_addstr(&autostash, "^0");
 727         argv_array_pushl(&stash_apply.args,
 728                          "stash", "apply", autostash.buf, NULL);
 729         stash_apply.git_cmd = 1;
 730         stash_apply.no_stderr = stash_apply.no_stdout =
 731                 stash_apply.no_stdin = 1;
 732         if (!run_command(&stash_apply))
 733                 printf(_("Applied autostash.\n"));
 734         else {
 735                 struct argv_array args = ARGV_ARRAY_INIT;
 736                 int res = 0;
 737
 738                 argv_array_pushl(&args,
 739                                  "stash", "store", "-m", "autostash", "-q",
 740                                  autostash.buf, NULL);
 741                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 742                         res = error(_("Cannot store %s"), autostash.buf);
 743                 argv_array_clear(&args);
 744                 strbuf_release(&autostash);
 745                 if (res)
 746                         return res;
 747
 748                 fprintf(stderr,
 749                         _("Applying autostash resulted in conflicts.\n"
 750                           "Your changes are safe in the stash.\n"
 751                           "You can run \"git stash pop\" or \"git stash drop\" "
 752                           "at any time.\n"));
 753         }
 754
 755         strbuf_release(&autostash);
 756         return 0;
 757 }
 758
 759 static int finish_rebase(struct rebase_options *opts)
 760 {
 761         struct strbuf dir = STRBUF_INIT;
 762         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 763         int ret = 0;
 764
 765         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 766         apply_autostash(opts);
 767         close_object_store(the_repository->objects);
 768         /*
 769          * We ignore errors in 'gc --auto', since the
 770          * user should see them.
 771          */
 772         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 773         if (opts->type == REBASE_INTERACTIVE) {
 774                 struct replay_opts replay = REPLAY_OPTS_INIT;
 775
 776                 replay.action = REPLAY_INTERACTIVE_REBASE;
 777                 ret = sequencer_remove_state(&replay);
 778         } else {
 779                 strbuf_addstr(&dir, opts->state_dir);
 780                 if (remove_dir_recursively(&dir, 0))
 781                         ret = error(_("could not remove '%s'"),
 782                                     opts->state_dir);
 783                 strbuf_release(&dir);
 784         }
 785
 786         return ret;
 787 }
 788
 789 static struct commit *peel_committish(const char *name)
 790 {
 791         struct object *obj;
 792         struct object_id oid;
 793
 794         if (get_oid(name, &oid))
 795                 return NULL;
 796         obj = parse_object(the_repository, &oid);
 797         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 798 }
 799
 800 static void add_var(struct strbuf *buf, const char *name, const char *value)
 801 {
 802         if (!value)
 803                 strbuf_addf(buf, "unset %s; ", name);
 804         else {
 805                 strbuf_addf(buf, "%s=", name);
 806                 sq_quote_buf(buf, value);
 807                 strbuf_addstr(buf, "; ");
 808         }
 809 }
 810
 811 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 812
 813 #define RESET_HEAD_DETACH (1<<0)
 814 #define RESET_HEAD_HARD (1<<1)
 815 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 816 #define RESET_HEAD_REFS_ONLY (1<<3)
 817 #define RESET_ORIG_HEAD (1<<4)
 818
 819 static int reset_head(struct object_id *oid, const char *action,
 820                       const char *switch_to_branch, unsigned flags,
 821                       const char *reflog_orig_head, const char *reflog_head)
 822 {
 823         unsigned detach_head = flags & RESET_HEAD_DETACH;
 824         unsigned reset_hard = flags & RESET_HEAD_HARD;
 825         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 826         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 827         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 828         struct object_id head_oid;
 829         struct tree_desc desc[2] = { { NULL }, { NULL } };
 830         struct lock_file lock = LOCK_INIT;
 831         struct unpack_trees_options unpack_tree_opts;
 832         struct tree *tree;
 833         const char *reflog_action;
 834         struct strbuf msg = STRBUF_INIT;
 835         size_t prefix_len;
 836         struct object_id *orig = NULL, oid_orig,
 837                 *old_orig = NULL, oid_old_orig;
 838         int ret = 0, nr = 0;
 839
 840         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 841                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 842
 843         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 844                 ret = -1;
 845                 goto leave_reset_head;
 846         }
 847
 848         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 849                 ret = error(_("could not determine HEAD revision"));
 850                 goto leave_reset_head;
 851         }
 852
 853         if (!oid)
 854                 oid = &head_oid;
 855
 856         if (refs_only)
 857                 goto reset_head_refs;
 858
 859         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 860         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 861         unpack_tree_opts.head_idx = 1;
 862         unpack_tree_opts.src_index = the_repository->index;
 863         unpack_tree_opts.dst_index = the_repository->index;
 864         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 865         unpack_tree_opts.update = 1;
 866         unpack_tree_opts.merge = 1;
 867         if (!detach_head)
 868                 unpack_tree_opts.reset = 1;
 869
 870         if (repo_read_index_unmerged(the_repository) < 0) {
 871                 ret = error(_("could not read index"));
 872                 goto leave_reset_head;
 873         }
 874
 875         if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 876                 ret = error(_("failed to find tree of %s"),
 877                             oid_to_hex(&head_oid));
 878                 goto leave_reset_head;
 879         }
 880
 881         if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 882                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 883                 goto leave_reset_head;
 884         }
 885
 886         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 887                 ret = -1;
 888                 goto leave_reset_head;
 889         }
 890
 891         tree = parse_tree_indirect(oid);
 892         prime_cache_tree(the_repository, the_repository->index, tree);
 893
 894         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 895                 ret = error(_("could not write index"));
 896                 goto leave_reset_head;
 897         }
 898
 899 reset_head_refs:
 900         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 901         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 902         prefix_len = msg.len;
 903
 904         if (update_orig_head) {
 905                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 906                         old_orig = &oid_old_orig;
 907                 if (!get_oid("HEAD", &oid_orig)) {
 908                         orig = &oid_orig;
 909                         if (!reflog_orig_head) {
 910                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 911                                 reflog_orig_head = msg.buf;
 912                         }
 913                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 914                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 915                 } else if (old_orig)
 916                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 917         }
 918
 919         if (!reflog_head) {
 920                 strbuf_setlen(&msg, prefix_len);
 921                 strbuf_addstr(&msg, "updating HEAD");
 922                 reflog_head = msg.buf;
 923         }
 924         if (!switch_to_branch)
 925                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 926                                  detach_head ? REF_NO_DEREF : 0,
 927                                  UPDATE_REFS_MSG_ON_ERR);
 928         else {
 929                 ret = update_ref(reflog_head, switch_to_branch, oid,
 930                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 931                 if (!ret)
 932                         ret = create_symref("HEAD", switch_to_branch,
 933                                             reflog_head);
 934         }
 935         if (run_hook)
 936                 run_hook_le(NULL, "post-checkout",
 937                             oid_to_hex(orig ? orig : &null_oid),
 938                             oid_to_hex(oid), "1", NULL);
 939
 940 leave_reset_head:
 941         strbuf_release(&msg);
 942         rollback_lock_file(&lock);
 943         while (nr)
 944                 free((void *)desc[--nr].buffer);
 945         return ret;
 946 }
 947
 948 static int move_to_original_branch(struct rebase_options *opts)
 949 {
 950         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 951         int ret;
 952
 953         if (!opts->head_name)
 954                 return 0; /* nothing to move back to */
 955
 956         if (!opts->onto)
 957                 BUG("move_to_original_branch without onto");
 958
 959         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 960                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
 961         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 962                     opts->head_name);
 963         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 964                          orig_head_reflog.buf, head_reflog.buf);
 965
 966         strbuf_release(&orig_head_reflog);
 967         strbuf_release(&head_reflog);
 968         return ret;
 969 }
 970
 971 static const char *resolvemsg =
 972 N_("Resolve all conflicts manually, mark them as resolved with\n"
 973 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 974 "You can instead skip this commit: run \"git rebase --skip\".\n"
 975 "To abort and get back to the state before \"git rebase\", run "
 976 "\"git rebase --abort\".");
 977
 978 static int run_am(struct rebase_options *opts)
 979 {
 980         struct child_process am = CHILD_PROCESS_INIT;
 981         struct child_process format_patch = CHILD_PROCESS_INIT;
 982         struct strbuf revisions = STRBUF_INIT;
 983         int status;
 984         char *rebased_patches;
 985
 986         am.git_cmd = 1;
 987         argv_array_push(&am.args, "am");
 988
 989         if (opts->ignore_whitespace)
 990                 argv_array_push(&am.args, "--ignore-whitespace");
 991         if (opts->committer_date_is_author_date)
 992                 argv_array_push(&opts->git_am_opts, "--committer-date-is-author-date");
 993         if (opts->ignore_date)
 994                 argv_array_push(&opts->git_am_opts, "--ignore-date");
 995         if (opts->action && !strcmp("continue", opts->action)) {
 996                 argv_array_push(&am.args, "--resolved");
 997                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 998                 if (opts->gpg_sign_opt)
 999                         argv_array_push(&am.args, opts->gpg_sign_opt);
1000                 status = run_command(&am);
1001                 if (status)
1002                         return status;
1003
1004                 return move_to_original_branch(opts);
1005         }
1006         if (opts->action && !strcmp("skip", opts->action)) {
1007                 argv_array_push(&am.args, "--skip");
1008                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1009                 status = run_command(&am);
1010                 if (status)
1011                         return status;
1012
1013                 return move_to_original_branch(opts);
1014         }
1015         if (opts->action && !strcmp("show-current-patch", opts->action)) {
1016                 argv_array_push(&am.args, "--show-current-patch");
1017                 return run_command(&am);
1018         }
1019
1020         strbuf_addf(&revisions, "%s...%s",
1021                     oid_to_hex(opts->root ?
1022                                /* this is now equivalent to !opts->upstream */
1023                                &opts->onto->object.oid :
1024                                &opts->upstream->object.oid),
1025                     oid_to_hex(&opts->orig_head));
1026
1027         rebased_patches = xstrdup(git_path("rebased-patches"));
1028         format_patch.out = open(rebased_patches,
1029                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1030         if (format_patch.out < 0) {
1031                 status = error_errno(_("could not open '%s' for writing"),
1032                                      rebased_patches);
1033                 free(rebased_patches);
1034                 argv_array_clear(&am.args);
1035                 return status;
1036         }
1037
1038         format_patch.git_cmd = 1;
1039         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1040                          "--full-index", "--cherry-pick", "--right-only",
1041                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1042                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
1043         if (opts->git_format_patch_opt.len)
1044                 argv_array_split(&format_patch.args,
1045                                  opts->git_format_patch_opt.buf);
1046         argv_array_push(&format_patch.args, revisions.buf);
1047         if (opts->restrict_revision)
1048                 argv_array_pushf(&format_patch.args, "^%s",
1049                                  oid_to_hex(&opts->restrict_revision->object.oid));
1050
1051         status = run_command(&format_patch);
1052         if (status) {
1053                 unlink(rebased_patches);
1054                 free(rebased_patches);
1055                 argv_array_clear(&am.args);
1056
1057                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1058                            "HEAD", NULL);
1059                 error(_("\ngit encountered an error while preparing the "
1060                         "patches to replay\n"
1061                         "these revisions:\n"
1062                         "\n    %s\n\n"
1063                         "As a result, git cannot rebase them."),
1064                       opts->revisions);
1065
1066                 strbuf_release(&revisions);
1067                 return status;
1068         }
1069         strbuf_release(&revisions);
1070
1071         am.in = open(rebased_patches, O_RDONLY);
1072         if (am.in < 0) {
1073                 status = error_errno(_("could not open '%s' for reading"),
1074                                      rebased_patches);
1075                 free(rebased_patches);
1076                 argv_array_clear(&am.args);
1077                 return status;
1078         }
1079
1080         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1081         argv_array_push(&am.args, "--rebasing");
1082         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1083         argv_array_push(&am.args, "--patch-format=mboxrd");
1084         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1085                 argv_array_push(&am.args, "--rerere-autoupdate");
1086         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1087                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1088         if (opts->gpg_sign_opt)
1089                 argv_array_push(&am.args, opts->gpg_sign_opt);
1090         status = run_command(&am);
1091         unlink(rebased_patches);
1092         free(rebased_patches);
1093
1094         if (!status) {
1095                 return move_to_original_branch(opts);
1096         }
1097
1098         if (is_directory(opts->state_dir))
1099                 rebase_write_basic_state(opts);
1100
1101         return status;
1102 }
1103
1104 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1105 {
1106         const char *argv[] = { NULL, NULL };
1107         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1108         int status;
1109         const char *backend, *backend_func;
1110
1111         if (opts->type == REBASE_INTERACTIVE) {
1112                 /* Run builtin interactive rebase */
1113                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1114                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1115                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1116                         opts->autosquash = 0;
1117                 }
1118                 if (opts->gpg_sign_opt) {
1119                         /* remove the leading "-S" */
1120                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1121                         free(opts->gpg_sign_opt);
1122                         opts->gpg_sign_opt = tmp;
1123                 }
1124
1125                 status = run_rebase_interactive(opts, action);
1126                 goto finished_rebase;
1127         }
1128
1129         if (opts->type == REBASE_AM) {
1130                 status = run_am(opts);
1131                 goto finished_rebase;
1132         }
1133
1134         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1135         add_var(&script_snippet, "state_dir", opts->state_dir);
1136
1137         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1138         add_var(&script_snippet, "upstream", opts->upstream ?
1139                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1140         add_var(&script_snippet, "head_name",
1141                 opts->head_name ? opts->head_name : "detached HEAD");
1142         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1143         add_var(&script_snippet, "onto", opts->onto ?
1144                 oid_to_hex(&opts->onto->object.oid) : NULL);
1145         add_var(&script_snippet, "onto_name", opts->onto_name);
1146         add_var(&script_snippet, "revisions", opts->revisions);
1147         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1148                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1149         add_var(&script_snippet, "GIT_QUIET",
1150                 opts->flags & REBASE_NO_QUIET ? "" : "t");
1151         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1152         add_var(&script_snippet, "git_am_opt", buf.buf);
1153         strbuf_release(&buf);
1154         add_var(&script_snippet, "verbose",
1155                 opts->flags & REBASE_VERBOSE ? "t" : "");
1156         add_var(&script_snippet, "diffstat",
1157                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1158         add_var(&script_snippet, "force_rebase",
1159                 opts->flags & REBASE_FORCE ? "t" : "");
1160         if (opts->switch_to)
1161                 add_var(&script_snippet, "switch_to", opts->switch_to);
1162         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1163         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1164         add_var(&script_snippet, "allow_rerere_autoupdate",
1165                 opts->allow_rerere_autoupdate ?
1166                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1167                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1168         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1169         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1170         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1171         add_var(&script_snippet, "cmd", opts->cmd);
1172         add_var(&script_snippet, "allow_empty_message",
1173                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1174         add_var(&script_snippet, "rebase_merges",
1175                 opts->rebase_merges ? "t" : "");
1176         add_var(&script_snippet, "rebase_cousins",
1177                 opts->rebase_cousins ? "t" : "");
1178         add_var(&script_snippet, "strategy", opts->strategy);
1179         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1180         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1181         add_var(&script_snippet, "squash_onto",
1182                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1183         add_var(&script_snippet, "git_format_patch_opt",
1184                 opts->git_format_patch_opt.buf);
1185
1186         if (is_interactive(opts) &&
1187             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1188                 strbuf_addstr(&script_snippet,
1189                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1190                 opts->autosquash = 0;
1191         }
1192
1193         switch (opts->type) {
1194         case REBASE_PRESERVE_MERGES:
1195                 backend = "git-rebase--preserve-merges";
1196                 backend_func = "git_rebase__preserve_merges";
1197                 break;
1198         default:
1199                 BUG("Unhandled rebase type %d", opts->type);
1200                 break;
1201         }
1202
1203         strbuf_addf(&script_snippet,
1204                     ". git-sh-setup && . %s && %s", backend, backend_func);
1205         argv[0] = script_snippet.buf;
1206
1207         status = run_command_v_opt(argv, RUN_USING_SHELL);
1208 finished_rebase:
1209         if (opts->dont_finish_rebase)
1210                 ; /* do nothing */
1211         else if (opts->type == REBASE_INTERACTIVE)
1212                 ; /* interactive rebase cleans up after itself */
1213         else if (status == 0) {
1214                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1215                         finish_rebase(opts);
1216         } else if (status == 2) {
1217                 struct strbuf dir = STRBUF_INIT;
1218
1219                 apply_autostash(opts);
1220                 strbuf_addstr(&dir, opts->state_dir);
1221                 remove_dir_recursively(&dir, 0);
1222                 strbuf_release(&dir);
1223                 die("Nothing to do");
1224         }
1225
1226         strbuf_release(&script_snippet);
1227
1228         return status ? -1 : 0;
1229 }
1230
1231 static int rebase_config(const char *var, const char *value, void *data)
1232 {
1233         struct rebase_options *opts = data;
1234
1235         if (!strcmp(var, "rebase.stat")) {
1236                 if (git_config_bool(var, value))
1237                         opts->flags |= REBASE_DIFFSTAT;
1238                 else
1239                         opts->flags &= ~REBASE_DIFFSTAT;
1240                 return 0;
1241         }
1242
1243         if (!strcmp(var, "rebase.autosquash")) {
1244                 opts->autosquash = git_config_bool(var, value);
1245                 return 0;
1246         }
1247
1248         if (!strcmp(var, "commit.gpgsign")) {
1249                 free(opts->gpg_sign_opt);
1250                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1251                         xstrdup("-S") : NULL;
1252                 return 0;
1253         }
1254
1255         if (!strcmp(var, "rebase.autostash")) {
1256                 opts->autostash = git_config_bool(var, value);
1257                 return 0;
1258         }
1259
1260         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1261                 opts->reschedule_failed_exec = git_config_bool(var, value);
1262                 return 0;
1263         }
1264
1265         if (!strcmp(var, "rebase.usebuiltin")) {
1266                 opts->use_legacy_rebase = !git_config_bool(var, value);
1267                 return 0;
1268         }
1269
1270         return git_default_config(var, value, data);
1271 }
1272
1273 /*
1274  * Determines whether the commits in from..to are linear, i.e. contain
1275  * no merge commits. This function *expects* `from` to be an ancestor of
1276  * `to`.
1277  */
1278 static int is_linear_history(struct commit *from, struct commit *to)
1279 {
1280         while (to && to != from) {
1281                 parse_commit(to);
1282                 if (!to->parents)
1283                         return 1;
1284                 if (to->parents->next)
1285                         return 0;
1286                 to = to->parents->item;
1287         }
1288         return 1;
1289 }
1290
1291 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1292                             struct commit *restrict_revision,
1293                             struct object_id *head_oid, struct object_id *merge_base)
1294 {
1295         struct commit *head = lookup_commit(the_repository, head_oid);
1296         struct commit_list *merge_bases = NULL;
1297         int res = 0;
1298
1299         if (!head)
1300                 goto done;
1301
1302         merge_bases = get_merge_bases(onto, head);
1303         if (!merge_bases || merge_bases->next) {
1304                 oidcpy(merge_base, &null_oid);
1305                 goto done;
1306         }
1307
1308         oidcpy(merge_base, &merge_bases->item->object.oid);
1309         if (!oideq(merge_base, &onto->object.oid))
1310                 goto done;
1311
1312         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1313                 goto done;
1314
1315         if (!upstream)
1316                 goto done;
1317
1318         free_commit_list(merge_bases);
1319         merge_bases = get_merge_bases(upstream, head);
1320         if (!merge_bases || merge_bases->next)
1321                 goto done;
1322
1323         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1324                 goto done;
1325
1326         res = 1;
1327
1328 done:
1329         free_commit_list(merge_bases);
1330         return res && is_linear_history(onto, head);
1331 }
1332
1333 /* -i followed by -m is still -i */
1334 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1335 {
1336         struct rebase_options *opts = opt->value;
1337
1338         BUG_ON_OPT_NEG(unset);
1339         BUG_ON_OPT_ARG(arg);
1340
1341         if (!is_interactive(opts))
1342                 opts->type = REBASE_MERGE;
1343
1344         return 0;
1345 }
1346
1347 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1348 static int parse_opt_interactive(const struct option *opt, const char *arg,
1349                                  int unset)
1350 {
1351         struct rebase_options *opts = opt->value;
1352
1353         BUG_ON_OPT_NEG(unset);
1354         BUG_ON_OPT_ARG(arg);
1355
1356         opts->type = REBASE_INTERACTIVE;
1357         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1358
1359         return 0;
1360 }
1361
1362 static void NORETURN error_on_missing_default_upstream(void)
1363 {
1364         struct branch *current_branch = branch_get(NULL);
1365
1366         printf(_("%s\n"
1367                  "Please specify which branch you want to rebase against.\n"
1368                  "See git-rebase(1) for details.\n"
1369                  "\n"
1370                  "    git rebase '<branch>'\n"
1371                  "\n"),
1372                 current_branch ? _("There is no tracking information for "
1373                         "the current branch.") :
1374                         _("You are not currently on a branch."));
1375
1376         if (current_branch) {
1377                 const char *remote = current_branch->remote_name;
1378
1379                 if (!remote)
1380                         remote = _("<remote>");
1381
1382                 printf(_("If you wish to set tracking information for this "
1383                          "branch you can do so with:\n"
1384                          "\n"
1385                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1386                          "\n"),
1387                        remote, current_branch->name);
1388         }
1389         exit(1);
1390 }
1391
1392 static void set_reflog_action(struct rebase_options *options)
1393 {
1394         const char *env;
1395         struct strbuf buf = STRBUF_INIT;
1396
1397         if (!is_interactive(options))
1398                 return;
1399
1400         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1401         if (env && strcmp("rebase", env))
1402                 return; /* only override it if it is "rebase" */
1403
1404         strbuf_addf(&buf, "rebase -i (%s)", options->action);
1405         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1406         strbuf_release(&buf);
1407 }
1408
1409 static int check_exec_cmd(const char *cmd)
1410 {
1411         if (strchr(cmd, '\n'))
1412                 return error(_("exec commands cannot contain newlines"));
1413
1414         /* Does the command consist purely of whitespace? */
1415         if (!cmd[strspn(cmd, " \t\r\f\v")])
1416                 return error(_("empty exec command"));
1417
1418         return 0;
1419 }
1420
1421
1422 int cmd_rebase(int argc, const char **argv, const char *prefix)
1423 {
1424         struct rebase_options options = REBASE_OPTIONS_INIT;
1425         const char *branch_name;
1426         int ret, flags, total_argc, in_progress = 0;
1427         int keep_base = 0;
1428         int ok_to_skip_pre_rebase = 0;
1429         struct strbuf msg = STRBUF_INIT;
1430         struct strbuf revisions = STRBUF_INIT;
1431         struct strbuf buf = STRBUF_INIT;
1432         struct object_id merge_base;
1433         enum action action = ACTION_NONE;
1434         const char *gpg_sign = NULL;
1435         struct string_list exec = STRING_LIST_INIT_NODUP;
1436         const char *rebase_merges = NULL;
1437         int fork_point = -1;
1438         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1439         struct object_id squash_onto;
1440         char *squash_onto_name = NULL;
1441         int reschedule_failed_exec = -1;
1442         struct option builtin_rebase_options[] = {
1443                 OPT_STRING(0, "onto", &options.onto_name,
1444                            N_("revision"),
1445                            N_("rebase onto given branch instead of upstream")),
1446                 OPT_BOOL(0, "keep-base", &keep_base,
1447                          N_("use the merge-base of upstream and branch as the current base")),
1448                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1449                          N_("allow pre-rebase hook to run")),
1450                 OPT_NEGBIT('q', "quiet", &options.flags,
1451                            N_("be quiet. implies --no-stat"),
1452                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1453                 OPT_BIT('v', "verbose", &options.flags,
1454                         N_("display a diffstat of what changed upstream"),
1455                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1456                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1457                         N_("do not show diffstat of what changed upstream"),
1458                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1459                 OPT_BOOL(0, "signoff", &options.signoff,
1460                          N_("add a Signed-off-by: line to each commit")),
1461                 OPT_BOOL(0, "committer-date-is-author-date",
1462                          &options.committer_date_is_author_date,
1463                          N_("make committer date match author date")),
1464                 OPT_BOOL(0, "reset-author-date", &options.ignore_date,
1465                          N_("ignore author date and use current date")),
1466                 OPT_HIDDEN_BOOL(0, "ignore-date", &options.ignore_date,
1467                                 N_("synonym of --reset-author-date")),
1468                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1469                                   N_("passed to 'git apply'"), 0),
1470                 OPT_BOOL(0, "ignore-whitespace", &options.ignore_whitespace,
1471                          N_("ignore changes in whitespace")),
1472                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1473                                   N_("action"), N_("passed to 'git apply'"), 0),
1474                 OPT_BIT('f', "force-rebase", &options.flags,
1475                         N_("cherry-pick all commits, even if unchanged"),
1476                         REBASE_FORCE),
1477                 OPT_BIT(0, "no-ff", &options.flags,
1478                         N_("cherry-pick all commits, even if unchanged"),
1479                         REBASE_FORCE),
1480                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1481                             ACTION_CONTINUE),
1482                 OPT_CMDMODE(0, "skip", &action,
1483                             N_("skip current patch and continue"), ACTION_SKIP),
1484                 OPT_CMDMODE(0, "abort", &action,
1485                             N_("abort and check out the original branch"),
1486                             ACTION_ABORT),
1487                 OPT_CMDMODE(0, "quit", &action,
1488                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1489                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1490                             "during an interactive rebase"), ACTION_EDIT_TODO),
1491                 OPT_CMDMODE(0, "show-current-patch", &action,
1492                             N_("show the patch file being applied or merged"),
1493                             ACTION_SHOW_CURRENT_PATCH),
1494                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1495                         N_("use merging strategies to rebase"),
1496                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1497                         parse_opt_merge },
1498                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1499                         N_("let the user edit the list of commits to rebase"),
1500                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1501                         parse_opt_interactive },
1502                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1503                               N_("(DEPRECATED) try to recreate merges instead of "
1504                                  "ignoring them"),
1505                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1506                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1507                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
1508                          N_("preserve empty commits during rebase")),
1509                 OPT_BOOL(0, "autosquash", &options.autosquash,
1510                          N_("move commits that begin with "
1511                             "squash!/fixup! under -i")),
1512                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1513                         N_("GPG-sign commits"),
1514                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1515                 OPT_BOOL(0, "autostash", &options.autostash,
1516                          N_("automatically stash/stash pop before and after")),
1517                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1518                                 N_("add exec lines after each commit of the "
1519                                    "editable list")),
1520                 OPT_BOOL(0, "allow-empty-message",
1521                          &options.allow_empty_message,
1522                          N_("allow rebasing commits with empty messages")),
1523                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1524                         N_("mode"),
1525                         N_("try to rebase merges instead of skipping them"),
1526                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1527                 OPT_BOOL(0, "fork-point", &fork_point,
1528                          N_("use 'merge-base --fork-point' to refine upstream")),
1529                 OPT_STRING('s', "strategy", &options.strategy,
1530                            N_("strategy"), N_("use the given merge strategy")),
1531                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1532                                 N_("option"),
1533                                 N_("pass the argument through to the merge "
1534                                    "strategy")),
1535                 OPT_BOOL(0, "root", &options.root,
1536                          N_("rebase all reachable commits up to the root(s)")),
1537                 OPT_BOOL(0, "reschedule-failed-exec",
1538                          &reschedule_failed_exec,
1539                          N_("automatically re-schedule any `exec` that fails")),
1540                 OPT_END(),
1541         };
1542         int i;
1543
1544         if (argc == 2 && !strcmp(argv[1], "-h"))
1545                 usage_with_options(builtin_rebase_usage,
1546                                    builtin_rebase_options);
1547
1548         options.allow_empty_message = 1;
1549         git_config(rebase_config, &options);
1550
1551         if (options.use_legacy_rebase ||
1552             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1553                 warning(_("the rebase.useBuiltin support has been removed!\n"
1554                           "See its entry in 'git help config' for details."));
1555
1556         strbuf_reset(&buf);
1557         strbuf_addf(&buf, "%s/applying", apply_dir());
1558         if(file_exists(buf.buf))
1559                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1560
1561         if (is_directory(apply_dir())) {
1562                 options.type = REBASE_AM;
1563                 options.state_dir = apply_dir();
1564         } else if (is_directory(merge_dir())) {
1565                 strbuf_reset(&buf);
1566                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1567                 if (is_directory(buf.buf)) {
1568                         options.type = REBASE_PRESERVE_MERGES;
1569                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1570                 } else {
1571                         strbuf_reset(&buf);
1572                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1573                         if(file_exists(buf.buf)) {
1574                                 options.type = REBASE_INTERACTIVE;
1575                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1576                         } else
1577                                 options.type = REBASE_MERGE;
1578                 }
1579                 options.state_dir = merge_dir();
1580         }
1581
1582         if (options.type != REBASE_UNSPECIFIED)
1583                 in_progress = 1;
1584
1585         total_argc = argc;
1586         argc = parse_options(argc, argv, prefix,
1587                              builtin_rebase_options,
1588                              builtin_rebase_usage, 0);
1589
1590         if (action != ACTION_NONE && total_argc != 2) {
1591                 usage_with_options(builtin_rebase_usage,
1592                                    builtin_rebase_options);
1593         }
1594
1595         if (argc > 2)
1596                 usage_with_options(builtin_rebase_usage,
1597                                    builtin_rebase_options);
1598
1599         if (options.type == REBASE_PRESERVE_MERGES)
1600                 warning(_("git rebase --preserve-merges is deprecated. "
1601                           "Use --rebase-merges instead."));
1602
1603         if (keep_base) {
1604                 if (options.onto_name)
1605                         die(_("cannot combine '--keep-base' with '--onto'"));
1606                 if (options.root)
1607                         die(_("cannot combine '--keep-base' with '--root'"));
1608         }
1609
1610         if (action != ACTION_NONE && !in_progress)
1611                 die(_("No rebase in progress?"));
1612         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1613
1614         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1615                 die(_("The --edit-todo action can only be used during "
1616                       "interactive rebase."));
1617
1618         if (trace2_is_enabled()) {
1619                 if (is_interactive(&options))
1620                         trace2_cmd_mode("interactive");
1621                 else if (exec.nr)
1622                         trace2_cmd_mode("interactive-exec");
1623                 else
1624                         trace2_cmd_mode(action_names[action]);
1625         }
1626
1627         switch (action) {
1628         case ACTION_CONTINUE: {
1629                 struct object_id head;
1630                 struct lock_file lock_file = LOCK_INIT;
1631                 int fd;
1632
1633                 options.action = "continue";
1634                 set_reflog_action(&options);
1635
1636                 /* Sanity check */
1637                 if (get_oid("HEAD", &head))
1638                         die(_("Cannot read HEAD"));
1639
1640                 fd = hold_locked_index(&lock_file, 0);
1641                 if (repo_read_index(the_repository) < 0)
1642                         die(_("could not read index"));
1643                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1644                               NULL);
1645                 if (0 <= fd)
1646                         repo_update_index_if_able(the_repository, &lock_file);
1647                 rollback_lock_file(&lock_file);
1648
1649                 if (has_unstaged_changes(the_repository, 1)) {
1650                         puts(_("You must edit all merge conflicts and then\n"
1651                                "mark them as resolved using git add"));
1652                         exit(1);
1653                 }
1654                 if (read_basic_state(&options))
1655                         exit(1);
1656                 goto run_rebase;
1657         }
1658         case ACTION_SKIP: {
1659                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1660
1661                 options.action = "skip";
1662                 set_reflog_action(&options);
1663
1664                 rerere_clear(the_repository, &merge_rr);
1665                 string_list_clear(&merge_rr, 1);
1666
1667                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1668                                NULL, NULL) < 0)
1669                         die(_("could not discard worktree changes"));
1670                 remove_branch_state(the_repository, 0);
1671                 if (read_basic_state(&options))
1672                         exit(1);
1673                 goto run_rebase;
1674         }
1675         case ACTION_ABORT: {
1676                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1677                 options.action = "abort";
1678                 set_reflog_action(&options);
1679
1680                 rerere_clear(the_repository, &merge_rr);
1681                 string_list_clear(&merge_rr, 1);
1682
1683                 if (read_basic_state(&options))
1684                         exit(1);
1685                 if (reset_head(&options.orig_head, "reset",
1686                                options.head_name, RESET_HEAD_HARD,
1687                                NULL, NULL) < 0)
1688                         die(_("could not move back to %s"),
1689                             oid_to_hex(&options.orig_head));
1690                 remove_branch_state(the_repository, 0);
1691                 ret = !!finish_rebase(&options);
1692                 goto cleanup;
1693         }
1694         case ACTION_QUIT: {
1695                 if (options.type == REBASE_INTERACTIVE) {
1696                         struct replay_opts replay = REPLAY_OPTS_INIT;
1697
1698                         replay.action = REPLAY_INTERACTIVE_REBASE;
1699                         ret = !!sequencer_remove_state(&replay);
1700                 } else {
1701                         strbuf_reset(&buf);
1702                         strbuf_addstr(&buf, options.state_dir);
1703                         ret = !!remove_dir_recursively(&buf, 0);
1704                         if (ret)
1705                                 error(_("could not remove '%s'"),
1706                                        options.state_dir);
1707                 }
1708                 goto cleanup;
1709         }
1710         case ACTION_EDIT_TODO:
1711                 options.action = "edit-todo";
1712                 options.dont_finish_rebase = 1;
1713                 goto run_rebase;
1714         case ACTION_SHOW_CURRENT_PATCH:
1715                 options.action = "show-current-patch";
1716                 options.dont_finish_rebase = 1;
1717                 goto run_rebase;
1718         case ACTION_NONE:
1719                 break;
1720         default:
1721                 BUG("action: %d", action);
1722         }
1723
1724         /* Make sure no rebase is in progress */
1725         if (in_progress) {
1726                 const char *last_slash = strrchr(options.state_dir, '/');
1727                 const char *state_dir_base =
1728                         last_slash ? last_slash + 1 : options.state_dir;
1729                 const char *cmd_live_rebase =
1730                         "git rebase (--continue | --abort | --skip)";
1731                 strbuf_reset(&buf);
1732                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1733                 die(_("It seems that there is already a %s directory, and\n"
1734                       "I wonder if you are in the middle of another rebase.  "
1735                       "If that is the\n"
1736                       "case, please try\n\t%s\n"
1737                       "If that is not the case, please\n\t%s\n"
1738                       "and run me again.  I am stopping in case you still "
1739                       "have something\n"
1740                       "valuable there.\n"),
1741                     state_dir_base, cmd_live_rebase, buf.buf);
1742         }
1743
1744         if (options.committer_date_is_author_date ||
1745             options.ignore_date)
1746                 options.flags |= REBASE_FORCE;
1747
1748         for (i = 0; i < options.git_am_opts.argc; i++) {
1749                 const char *option = options.git_am_opts.argv[i], *p;
1750                 if (!strcmp(option, "--whitespace=fix") ||
1751                     !strcmp(option, "--whitespace=strip"))
1752                         options.flags |= REBASE_FORCE;
1753                 else if (skip_prefix(option, "-C", &p)) {
1754                         while (*p)
1755                                 if (!isdigit(*(p++)))
1756                                         die(_("switch `C' expects a "
1757                                               "numerical value"));
1758                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1759                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1760                             strcmp(p, "error") && strcmp(p, "error-all"))
1761                                 die("Invalid whitespace option: '%s'", p);
1762                 }
1763         }
1764
1765         for (i = 0; i < exec.nr; i++)
1766                 if (check_exec_cmd(exec.items[i].string))
1767                         exit(1);
1768
1769         if (!(options.flags & REBASE_NO_QUIET))
1770                 argv_array_push(&options.git_am_opts, "-q");
1771
1772         if (options.keep_empty)
1773                 imply_interactive(&options, "--keep-empty");
1774
1775         if (gpg_sign) {
1776                 free(options.gpg_sign_opt);
1777                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1778         }
1779
1780         if (exec.nr) {
1781                 int i;
1782
1783                 imply_interactive(&options, "--exec");
1784
1785                 strbuf_reset(&buf);
1786                 for (i = 0; i < exec.nr; i++)
1787                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1788                 options.cmd = xstrdup(buf.buf);
1789         }
1790
1791         if (rebase_merges) {
1792                 if (!*rebase_merges)
1793                         ; /* default mode; do nothing */
1794                 else if (!strcmp("rebase-cousins", rebase_merges))
1795                         options.rebase_cousins = 1;
1796                 else if (strcmp("no-rebase-cousins", rebase_merges))
1797                         die(_("Unknown mode: %s"), rebase_merges);
1798                 options.rebase_merges = 1;
1799                 imply_interactive(&options, "--rebase-merges");
1800         }
1801
1802         if (strategy_options.nr) {
1803                 int i;
1804
1805                 if (!options.strategy)
1806                         options.strategy = "recursive";
1807
1808                 strbuf_reset(&buf);
1809                 for (i = 0; i < strategy_options.nr; i++)
1810                         strbuf_addf(&buf, " --%s",
1811                                     strategy_options.items[i].string);
1812                 options.strategy_opts = xstrdup(buf.buf);
1813         }
1814
1815         if (options.strategy) {
1816                 options.strategy = xstrdup(options.strategy);
1817                 switch (options.type) {
1818                 case REBASE_AM:
1819                         die(_("--strategy requires --merge or --interactive"));
1820                 case REBASE_MERGE:
1821                 case REBASE_INTERACTIVE:
1822                 case REBASE_PRESERVE_MERGES:
1823                         /* compatible */
1824                         break;
1825                 case REBASE_UNSPECIFIED:
1826                         options.type = REBASE_MERGE;
1827                         break;
1828                 default:
1829                         BUG("unhandled rebase type (%d)", options.type);
1830                 }
1831         }
1832
1833         if (options.type == REBASE_MERGE)
1834                 imply_interactive(&options, "--merge");
1835
1836         if (options.root && !options.onto_name)
1837                 imply_interactive(&options, "--root without --onto");
1838
1839         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1840                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1841
1842         switch (options.type) {
1843         case REBASE_MERGE:
1844         case REBASE_INTERACTIVE:
1845         case REBASE_PRESERVE_MERGES:
1846                 options.state_dir = merge_dir();
1847                 break;
1848         case REBASE_AM:
1849                 options.state_dir = apply_dir();
1850                 break;
1851         default:
1852                 /* the default rebase backend is `--am` */
1853                 options.type = REBASE_AM;
1854                 options.state_dir = apply_dir();
1855                 break;
1856         }
1857
1858         if (reschedule_failed_exec > 0 && !is_interactive(&options))
1859                 die(_("--reschedule-failed-exec requires "
1860                       "--exec or --interactive"));
1861         if (reschedule_failed_exec >= 0)
1862                 options.reschedule_failed_exec = reschedule_failed_exec;
1863
1864         if (options.git_am_opts.argc) {
1865                 /* all am options except -q are compatible only with --am */
1866                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1867                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1868                                 break;
1869
1870                 if (is_interactive(&options) && i >= 0)
1871                         die(_("cannot combine am options with either "
1872                               "interactive or merge options"));
1873         }
1874
1875         if (options.signoff) {
1876                 if (options.type == REBASE_PRESERVE_MERGES)
1877                         die("cannot combine '--signoff' with "
1878                             "'--preserve-merges'");
1879                 argv_array_push(&options.git_am_opts, "--signoff");
1880                 options.flags |= REBASE_FORCE;
1881         }
1882
1883         if (options.type == REBASE_PRESERVE_MERGES) {
1884                 /*
1885                  * Note: incompatibility with --signoff handled in signoff block above
1886                  * Note: incompatibility with --interactive is just a strong warning;
1887                  *       git-rebase.txt caveats with "unless you know what you are doing"
1888                  */
1889                 if (options.rebase_merges)
1890                         die(_("cannot combine '--preserve-merges' with "
1891                               "'--rebase-merges'"));
1892
1893                 if (options.reschedule_failed_exec)
1894                         die(_("error: cannot combine '--preserve-merges' with "
1895                               "'--reschedule-failed-exec'"));
1896         }
1897
1898         if (!options.root) {
1899                 if (argc < 1) {
1900                         struct branch *branch;
1901
1902                         branch = branch_get(NULL);
1903                         options.upstream_name = branch_get_upstream(branch,
1904                                                                     NULL);
1905                         if (!options.upstream_name)
1906                                 error_on_missing_default_upstream();
1907                         if (fork_point < 0)
1908                                 fork_point = 1;
1909                 } else {
1910                         options.upstream_name = argv[0];
1911                         argc--;
1912                         argv++;
1913                         if (!strcmp(options.upstream_name, "-"))
1914                                 options.upstream_name = "@{-1}";
1915                 }
1916                 options.upstream = peel_committish(options.upstream_name);
1917                 if (!options.upstream)
1918                         die(_("invalid upstream '%s'"), options.upstream_name);
1919                 options.upstream_arg = options.upstream_name;
1920         } else {
1921                 if (!options.onto_name) {
1922                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1923                                         &squash_onto, NULL, NULL) < 0)
1924                                 die(_("Could not create new root commit"));
1925                         options.squash_onto = &squash_onto;
1926                         options.onto_name = squash_onto_name =
1927                                 xstrdup(oid_to_hex(&squash_onto));
1928                 } else
1929                         options.root_with_onto = 1;
1930
1931                 options.upstream_name = NULL;
1932                 options.upstream = NULL;
1933                 if (argc > 1)
1934                         usage_with_options(builtin_rebase_usage,
1935                                            builtin_rebase_options);
1936                 options.upstream_arg = "--root";
1937         }
1938
1939         /* Make sure the branch to rebase onto is valid. */
1940         if (keep_base) {
1941                 strbuf_reset(&buf);
1942                 strbuf_addstr(&buf, options.upstream_name);
1943                 strbuf_addstr(&buf, "...");
1944                 options.onto_name = xstrdup(buf.buf);
1945         } else if (!options.onto_name)
1946                 options.onto_name = options.upstream_name;
1947         if (strstr(options.onto_name, "...")) {
1948                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
1949                         if (keep_base)
1950                                 die(_("'%s': need exactly one merge base with branch"),
1951                                     options.upstream_name);
1952                         else
1953                                 die(_("'%s': need exactly one merge base"),
1954                                     options.onto_name);
1955                 }
1956                 options.onto = lookup_commit_or_die(&merge_base,
1957                                                     options.onto_name);
1958         } else {
1959                 options.onto = peel_committish(options.onto_name);
1960                 if (!options.onto)
1961                         die(_("Does not point to a valid commit '%s'"),
1962                                 options.onto_name);
1963         }
1964
1965         /*
1966          * If the branch to rebase is given, that is the branch we will rebase
1967          * branch_name -- branch/commit being rebased, or
1968          *                HEAD (already detached)
1969          * orig_head -- commit object name of tip of the branch before rebasing
1970          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1971          */
1972         if (argc == 1) {
1973                 /* Is it "rebase other branchname" or "rebase other commit"? */
1974                 branch_name = argv[0];
1975                 options.switch_to = argv[0];
1976
1977                 /* Is it a local branch? */
1978                 strbuf_reset(&buf);
1979                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1980                 if (!read_ref(buf.buf, &options.orig_head))
1981                         options.head_name = xstrdup(buf.buf);
1982                 /* If not is it a valid ref (branch or commit)? */
1983                 else if (!get_oid(branch_name, &options.orig_head))
1984                         options.head_name = NULL;
1985                 else
1986                         die(_("fatal: no such branch/commit '%s'"),
1987                             branch_name);
1988         } else if (argc == 0) {
1989                 /* Do not need to switch branches, we are already on it. */
1990                 options.head_name =
1991                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1992                                          &flags));
1993                 if (!options.head_name)
1994                         die(_("No such ref: %s"), "HEAD");
1995                 if (flags & REF_ISSYMREF) {
1996                         if (!skip_prefix(options.head_name,
1997                                          "refs/heads/", &branch_name))
1998                                 branch_name = options.head_name;
1999
2000                 } else {
2001                         FREE_AND_NULL(options.head_name);
2002                         branch_name = "HEAD";
2003                 }
2004                 if (get_oid("HEAD", &options.orig_head))
2005                         die(_("Could not resolve HEAD to a revision"));
2006         } else
2007                 BUG("unexpected number of arguments left to parse");
2008
2009         if (fork_point > 0) {
2010                 struct commit *head =
2011                         lookup_commit_reference(the_repository,
2012                                                 &options.orig_head);
2013                 options.restrict_revision =
2014                         get_fork_point(options.upstream_name, head);
2015         }
2016
2017         if (repo_read_index(the_repository) < 0)
2018                 die(_("could not read index"));
2019
2020         if (options.autostash) {
2021                 struct lock_file lock_file = LOCK_INIT;
2022                 int fd;
2023
2024                 fd = hold_locked_index(&lock_file, 0);
2025                 refresh_cache(REFRESH_QUIET);
2026                 if (0 <= fd)
2027                         repo_update_index_if_able(the_repository, &lock_file);
2028                 rollback_lock_file(&lock_file);
2029
2030                 if (has_unstaged_changes(the_repository, 1) ||
2031                     has_uncommitted_changes(the_repository, 1)) {
2032                         const char *autostash =
2033                                 state_dir_path("autostash", &options);
2034                         struct child_process stash = CHILD_PROCESS_INIT;
2035                         struct object_id oid;
2036
2037                         argv_array_pushl(&stash.args,
2038                                          "stash", "create", "autostash", NULL);
2039                         stash.git_cmd = 1;
2040                         stash.no_stdin = 1;
2041                         strbuf_reset(&buf);
2042                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
2043                                 die(_("Cannot autostash"));
2044                         strbuf_trim_trailing_newline(&buf);
2045                         if (get_oid(buf.buf, &oid))
2046                                 die(_("Unexpected stash response: '%s'"),
2047                                     buf.buf);
2048                         strbuf_reset(&buf);
2049                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
2050
2051                         if (safe_create_leading_directories_const(autostash))
2052                                 die(_("Could not create directory for '%s'"),
2053                                     options.state_dir);
2054                         write_file(autostash, "%s", oid_to_hex(&oid));
2055                         printf(_("Created autostash: %s\n"), buf.buf);
2056                         if (reset_head(NULL, "reset --hard",
2057                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2058                                 die(_("could not reset --hard"));
2059
2060                         if (discard_index(the_repository->index) < 0 ||
2061                                 repo_read_index(the_repository) < 0)
2062                                 die(_("could not read index"));
2063                 }
2064         }
2065
2066         if (require_clean_work_tree(the_repository, "rebase",
2067                                     _("Please commit or stash them."), 1, 1)) {
2068                 ret = 1;
2069                 goto cleanup;
2070         }
2071
2072         /*
2073          * Now we are rebasing commits upstream..orig_head (or with --root,
2074          * everything leading up to orig_head) on top of onto.
2075          */
2076
2077         /*
2078          * Check if we are already based on onto with linear history,
2079          * in which case we could fast-forward without replacing the commits
2080          * with new commits recreated by replaying their changes. This
2081          * optimization must not be done if this is an interactive rebase.
2082          */
2083         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
2084                     &options.orig_head, &merge_base) &&
2085             !is_interactive(&options)) {
2086                 int flag;
2087
2088                 if (!(options.flags & REBASE_FORCE)) {
2089                         /* Lazily switch to the target branch if needed... */
2090                         if (options.switch_to) {
2091                                 struct object_id oid;
2092
2093                                 if (get_oid(options.switch_to, &oid) < 0) {
2094                                         ret = !!error(_("could not parse '%s'"),
2095                                                       options.switch_to);
2096                                         goto cleanup;
2097                                 }
2098
2099                                 strbuf_reset(&buf);
2100                                 strbuf_addf(&buf, "%s: checkout %s",
2101                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2102                                             options.switch_to);
2103                                 if (reset_head(&oid, "checkout",
2104                                                options.head_name,
2105                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2106                                                NULL, buf.buf) < 0) {
2107                                         ret = !!error(_("could not switch to "
2108                                                         "%s"),
2109                                                       options.switch_to);
2110                                         goto cleanup;
2111                                 }
2112                         }
2113
2114                         if (!(options.flags & REBASE_NO_QUIET))
2115                                 ; /* be quiet */
2116                         else if (!strcmp(branch_name, "HEAD") &&
2117                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2118                                 puts(_("HEAD is up to date."));
2119                         else
2120                                 printf(_("Current branch %s is up to date.\n"),
2121                                        branch_name);
2122                         ret = !!finish_rebase(&options);
2123                         goto cleanup;
2124                 } else if (!(options.flags & REBASE_NO_QUIET))
2125                         ; /* be quiet */
2126                 else if (!strcmp(branch_name, "HEAD") &&
2127                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2128                         puts(_("HEAD is up to date, rebase forced."));
2129                 else
2130                         printf(_("Current branch %s is up to date, rebase "
2131                                  "forced.\n"), branch_name);
2132         }
2133
2134         /* If a hook exists, give it a chance to interrupt*/
2135         if (!ok_to_skip_pre_rebase &&
2136             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2137                         argc ? argv[0] : NULL, NULL))
2138                 die(_("The pre-rebase hook refused to rebase."));
2139
2140         if (options.flags & REBASE_DIFFSTAT) {
2141                 struct diff_options opts;
2142
2143                 if (options.flags & REBASE_VERBOSE) {
2144                         if (is_null_oid(&merge_base))
2145                                 printf(_("Changes to %s:\n"),
2146                                        oid_to_hex(&options.onto->object.oid));
2147                         else
2148                                 printf(_("Changes from %s to %s:\n"),
2149                                        oid_to_hex(&merge_base),
2150                                        oid_to_hex(&options.onto->object.oid));
2151                 }
2152
2153                 /* We want color (if set), but no pager */
2154                 diff_setup(&opts);
2155                 opts.stat_width = -1; /* use full terminal width */
2156                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2157                 opts.output_format |=
2158                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2159                 opts.detect_rename = DIFF_DETECT_RENAME;
2160                 diff_setup_done(&opts);
2161                 diff_tree_oid(is_null_oid(&merge_base) ?
2162                               the_hash_algo->empty_tree : &merge_base,
2163                               &options.onto->object.oid, "", &opts);
2164                 diffcore_std(&opts);
2165                 diff_flush(&opts);
2166         }
2167
2168         if (is_interactive(&options))
2169                 goto run_rebase;
2170
2171         /* Detach HEAD and reset the tree */
2172         if (options.flags & REBASE_NO_QUIET)
2173                 printf(_("First, rewinding head to replay your work on top of "
2174                          "it...\n"));
2175
2176         strbuf_addf(&msg, "%s: checkout %s",
2177                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2178         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2179                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2180                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2181                        NULL, msg.buf))
2182                 die(_("Could not detach HEAD"));
2183         strbuf_release(&msg);
2184
2185         /*
2186          * If the onto is a proper descendant of the tip of the branch, then
2187          * we just fast-forwarded.
2188          */
2189         strbuf_reset(&msg);
2190         if (oideq(&merge_base, &options.orig_head)) {
2191                 printf(_("Fast-forwarded %s to %s.\n"),
2192                         branch_name, options.onto_name);
2193                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2194                         options.head_name ? options.head_name : "detached HEAD",
2195                         oid_to_hex(&options.onto->object.oid));
2196                 reset_head(NULL, "Fast-forwarded", options.head_name,
2197                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2198                 strbuf_release(&msg);
2199                 ret = !!finish_rebase(&options);
2200                 goto cleanup;
2201         }
2202
2203         strbuf_addf(&revisions, "%s..%s",
2204                     options.root ? oid_to_hex(&options.onto->object.oid) :
2205                     (options.restrict_revision ?
2206                      oid_to_hex(&options.restrict_revision->object.oid) :
2207                      oid_to_hex(&options.upstream->object.oid)),
2208                     oid_to_hex(&options.orig_head));
2209
2210         options.revisions = revisions.buf;
2211
2212 run_rebase:
2213         ret = !!run_specific_rebase(&options, action);
2214
2215 cleanup:
2216         strbuf_release(&buf);
2217         strbuf_release(&revisions);
2218         free(options.head_name);
2219         free(options.gpg_sign_opt);
2220         free(options.cmd);
2221         free(squash_onto_name);
2222         return ret;
2223 }