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