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