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 #include "builtin.h"
   8 #include "run-command.h"
   9 #include "exec-cmd.h"
  10 #include "argv-array.h"
  11 #include "dir.h"
  12 #include "packfile.h"
  13 #include "refs.h"
  14 #include "quote.h"
  15 #include "config.h"
  16 #include "cache-tree.h"
  17 #include "unpack-trees.h"
  18 #include "lockfile.h"
  19 #include "parse-options.h"
  20 #include "commit.h"
  21 #include "diff.h"
  22 #include "wt-status.h"
  23 #include "revision.h"
  24 #include "rerere.h"
  25
  26 static char const * const builtin_rebase_usage[] = {
  27         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  28                 "[<upstream>] [<branch>]"),
  29         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  30                 "--root [<branch>]"),
  31         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  32         NULL
  33 };
  34
  35 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  36 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  37
  38 enum rebase_type {
  39         REBASE_UNSPECIFIED = -1,
  40         REBASE_AM,
  41         REBASE_MERGE,
  42         REBASE_INTERACTIVE,
  43         REBASE_PRESERVE_MERGES
  44 };
  45
  46 static int use_builtin_rebase(void)
  47 {
  48         struct child_process cp = CHILD_PROCESS_INIT;
  49         struct strbuf out = STRBUF_INIT;
  50         int ret;
  51
  52         argv_array_pushl(&cp.args,
  53                          "config", "--bool", "rebase.usebuiltin", NULL);
  54         cp.git_cmd = 1;
  55         if (capture_command(&cp, &out, 6)) {
  56                 strbuf_release(&out);
  57                 return 0;
  58         }
  59
  60         strbuf_trim(&out);
  61         ret = !strcmp("true", out.buf);
  62         strbuf_release(&out);
  63         return ret;
  64 }
  65
  66 static int apply_autostash(void)
  67 {
  68         warning("TODO");
  69         return 0;
  70 }
  71
  72 struct rebase_options {
  73         enum rebase_type type;
  74         const char *state_dir;
  75         struct commit *upstream;
  76         const char *upstream_name;
  77         const char *upstream_arg;
  78         char *head_name;
  79         struct object_id orig_head;
  80         struct commit *onto;
  81         const char *onto_name;
  82         const char *revisions;
  83         const char *switch_to;
  84         int root;
  85         struct commit *restrict_revision;
  86         int dont_finish_rebase;
  87         enum {
  88                 REBASE_NO_QUIET = 1<<0,
  89                 REBASE_VERBOSE = 1<<1,
  90                 REBASE_DIFFSTAT = 1<<2,
  91                 REBASE_FORCE = 1<<3,
  92                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  93         } flags;
  94         struct strbuf git_am_opt;
  95         const char *action;
  96         int signoff;
  97         int allow_rerere_autoupdate;
  98         int keep_empty;
  99         int autosquash;
 100         char *gpg_sign_opt;
 101 };
 102
 103 static int is_interactive(struct rebase_options *opts)
 104 {
 105         return opts->type == REBASE_INTERACTIVE ||
 106                 opts->type == REBASE_PRESERVE_MERGES;
 107 }
 108
 109 static void imply_interactive(struct rebase_options *opts, const char *option)
 110 {
 111         switch (opts->type) {
 112         case REBASE_AM:
 113                 die(_("%s requires an interactive rebase"), option);
 114                 break;
 115         case REBASE_INTERACTIVE:
 116         case REBASE_PRESERVE_MERGES:
 117                 break;
 118         case REBASE_MERGE:
 119                 /* we silently *upgrade* --merge to --interactive if needed */
 120         default:
 121                 opts->type = REBASE_INTERACTIVE; /* implied */
 122                 break;
 123         }
 124 }
 125
 126 /* Returns the filename prefixed by the state_dir */
 127 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 128 {
 129         static struct strbuf path = STRBUF_INIT;
 130         static size_t prefix_len;
 131
 132         if (!prefix_len) {
 133                 strbuf_addf(&path, "%s/", opts->state_dir);
 134                 prefix_len = path.len;
 135         }
 136
 137         strbuf_setlen(&path, prefix_len);
 138         strbuf_addstr(&path, filename);
 139         return path.buf;
 140 }
 141
 142 /* Read one file, then strip line endings */
 143 static int read_one(const char *path, struct strbuf *buf)
 144 {
 145         if (strbuf_read_file(buf, path, 0) < 0)
 146                 return error_errno(_("could not read '%s'"), path);
 147         strbuf_trim_trailing_newline(buf);
 148         return 0;
 149 }
 150
 151 /* Initialize the rebase options from the state directory. */
 152 static int read_basic_state(struct rebase_options *opts)
 153 {
 154         struct strbuf head_name = STRBUF_INIT;
 155         struct strbuf buf = STRBUF_INIT;
 156         struct object_id oid;
 157
 158         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 159             read_one(state_dir_path("onto", opts), &buf))
 160                 return -1;
 161         opts->head_name = starts_with(head_name.buf, "refs/") ?
 162                 xstrdup(head_name.buf) : NULL;
 163         strbuf_release(&head_name);
 164         if (get_oid(buf.buf, &oid))
 165                 return error(_("could not get 'onto': '%s'"), buf.buf);
 166         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 167
 168         /*
 169          * We always write to orig-head, but interactive rebase used to write to
 170          * head. Fall back to reading from head to cover for the case that the
 171          * user upgraded git with an ongoing interactive rebase.
 172          */
 173         strbuf_reset(&buf);
 174         if (file_exists(state_dir_path("orig-head", opts))) {
 175                 if (read_one(state_dir_path("orig-head", opts), &buf))
 176                         return -1;
 177         } else if (read_one(state_dir_path("head", opts), &buf))
 178                 return -1;
 179         if (get_oid(buf.buf, &opts->orig_head))
 180                 return error(_("invalid orig-head: '%s'"), buf.buf);
 181
 182         strbuf_reset(&buf);
 183         if (read_one(state_dir_path("quiet", opts), &buf))
 184                 return -1;
 185         if (buf.len)
 186                 opts->flags &= ~REBASE_NO_QUIET;
 187         else
 188                 opts->flags |= REBASE_NO_QUIET;
 189
 190         if (file_exists(state_dir_path("verbose", opts)))
 191                 opts->flags |= REBASE_VERBOSE;
 192
 193         if (file_exists(state_dir_path("signoff", opts))) {
 194                 opts->signoff = 1;
 195                 opts->flags |= REBASE_FORCE;
 196         }
 197
 198         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 199                 strbuf_reset(&buf);
 200                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 201                             &buf))
 202                         return -1;
 203                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 204                         opts->allow_rerere_autoupdate = 1;
 205                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 206                         opts->allow_rerere_autoupdate = 0;
 207                 else
 208                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 209                                   "'%s'"), buf.buf);
 210         } else
 211                 opts->allow_rerere_autoupdate = -1;
 212
 213         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 214                 strbuf_reset(&buf);
 215                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 216                             &buf))
 217                         return -1;
 218                 free(opts->gpg_sign_opt);
 219                 opts->gpg_sign_opt = xstrdup(buf.buf);
 220         }
 221
 222         strbuf_release(&buf);
 223
 224         return 0;
 225 }
 226
 227 static int finish_rebase(struct rebase_options *opts)
 228 {
 229         struct strbuf dir = STRBUF_INIT;
 230         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 231
 232         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 233         apply_autostash();
 234         close_all_packs(the_repository->objects);
 235         /*
 236          * We ignore errors in 'gc --auto', since the
 237          * user should see them.
 238          */
 239         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 240         strbuf_addstr(&dir, opts->state_dir);
 241         remove_dir_recursively(&dir, 0);
 242         strbuf_release(&dir);
 243
 244         return 0;
 245 }
 246
 247 static struct commit *peel_committish(const char *name)
 248 {
 249         struct object *obj;
 250         struct object_id oid;
 251
 252         if (get_oid(name, &oid))
 253                 return NULL;
 254         obj = parse_object(the_repository, &oid);
 255         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 256 }
 257
 258 static void add_var(struct strbuf *buf, const char *name, const char *value)
 259 {
 260         if (!value)
 261                 strbuf_addf(buf, "unset %s; ", name);
 262         else {
 263                 strbuf_addf(buf, "%s=", name);
 264                 sq_quote_buf(buf, value);
 265                 strbuf_addstr(buf, "; ");
 266         }
 267 }
 268
 269 static int run_specific_rebase(struct rebase_options *opts)
 270 {
 271         const char *argv[] = { NULL, NULL };
 272         struct strbuf script_snippet = STRBUF_INIT;
 273         int status;
 274         const char *backend, *backend_func;
 275
 276         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 277         add_var(&script_snippet, "state_dir", opts->state_dir);
 278
 279         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 280         add_var(&script_snippet, "upstream", opts->upstream ?
 281                 oid_to_hex(&opts->upstream->object.oid) : NULL);
 282         add_var(&script_snippet, "head_name",
 283                 opts->head_name ? opts->head_name : "detached HEAD");
 284         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 285         add_var(&script_snippet, "onto", opts->onto ?
 286                 oid_to_hex(&opts->onto->object.oid) : NULL);
 287         add_var(&script_snippet, "onto_name", opts->onto_name);
 288         add_var(&script_snippet, "revisions", opts->revisions);
 289         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 290                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 291         add_var(&script_snippet, "GIT_QUIET",
 292                 opts->flags & REBASE_NO_QUIET ? "" : "t");
 293         add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
 294         add_var(&script_snippet, "verbose",
 295                 opts->flags & REBASE_VERBOSE ? "t" : "");
 296         add_var(&script_snippet, "diffstat",
 297                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
 298         add_var(&script_snippet, "force_rebase",
 299                 opts->flags & REBASE_FORCE ? "t" : "");
 300         if (opts->switch_to)
 301                 add_var(&script_snippet, "switch_to", opts->switch_to);
 302         add_var(&script_snippet, "action", opts->action ? opts->action : "");
 303         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 304         add_var(&script_snippet, "allow_rerere_autoupdate",
 305                 opts->allow_rerere_autoupdate < 0 ? "" :
 306                 opts->allow_rerere_autoupdate ?
 307                 "--rerere-autoupdate" : "--no-rerere-autoupdate");
 308         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 309         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 310         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 311
 312         switch (opts->type) {
 313         case REBASE_AM:
 314                 backend = "git-rebase--am";
 315                 backend_func = "git_rebase__am";
 316                 break;
 317         case REBASE_INTERACTIVE:
 318                 backend = "git-rebase--interactive";
 319                 backend_func = "git_rebase__interactive";
 320                 break;
 321         case REBASE_MERGE:
 322                 backend = "git-rebase--merge";
 323                 backend_func = "git_rebase__merge";
 324                 break;
 325         case REBASE_PRESERVE_MERGES:
 326                 backend = "git-rebase--preserve-merges";
 327                 backend_func = "git_rebase__preserve_merges";
 328                 break;
 329         default:
 330                 BUG("Unhandled rebase type %d", opts->type);
 331                 break;
 332         }
 333
 334         strbuf_addf(&script_snippet,
 335                     ". git-sh-setup && . git-rebase--common &&"
 336                     " . %s && %s", backend, backend_func);
 337         argv[0] = script_snippet.buf;
 338
 339         status = run_command_v_opt(argv, RUN_USING_SHELL);
 340         if (opts->dont_finish_rebase)
 341                 ; /* do nothing */
 342         else if (status == 0) {
 343                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 344                         finish_rebase(opts);
 345         } else if (status == 2) {
 346                 struct strbuf dir = STRBUF_INIT;
 347
 348                 apply_autostash();
 349                 strbuf_addstr(&dir, opts->state_dir);
 350                 remove_dir_recursively(&dir, 0);
 351                 strbuf_release(&dir);
 352                 die("Nothing to do");
 353         }
 354
 355         strbuf_release(&script_snippet);
 356
 357         return status ? -1 : 0;
 358 }
 359
 360 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 361
 362 static int reset_head(struct object_id *oid, const char *action,
 363                       const char *switch_to_branch, int detach_head)
 364 {
 365         struct object_id head_oid;
 366         struct tree_desc desc;
 367         struct lock_file lock = LOCK_INIT;
 368         struct unpack_trees_options unpack_tree_opts;
 369         struct tree *tree;
 370         const char *reflog_action;
 371         struct strbuf msg = STRBUF_INIT;
 372         size_t prefix_len;
 373         struct object_id *orig = NULL, oid_orig,
 374                 *old_orig = NULL, oid_old_orig;
 375         int ret = 0;
 376
 377         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 378                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 379
 380         if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 381                 return -1;
 382
 383         if (!oid) {
 384                 if (get_oid("HEAD", &head_oid)) {
 385                         rollback_lock_file(&lock);
 386                         return error(_("could not determine HEAD revision"));
 387                 }
 388                 oid = &head_oid;
 389         }
 390
 391         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 392         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 393         unpack_tree_opts.head_idx = 1;
 394         unpack_tree_opts.src_index = the_repository->index;
 395         unpack_tree_opts.dst_index = the_repository->index;
 396         unpack_tree_opts.fn = oneway_merge;
 397         unpack_tree_opts.update = 1;
 398         unpack_tree_opts.merge = 1;
 399         if (!detach_head)
 400                 unpack_tree_opts.reset = 1;
 401
 402         if (read_index_unmerged(the_repository->index) < 0) {
 403                 rollback_lock_file(&lock);
 404                 return error(_("could not read index"));
 405         }
 406
 407         if (!fill_tree_descriptor(&desc, oid)) {
 408                 error(_("failed to find tree of %s"), oid_to_hex(oid));
 409                 rollback_lock_file(&lock);
 410                 free((void *)desc.buffer);
 411                 return -1;
 412         }
 413
 414         if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 415                 rollback_lock_file(&lock);
 416                 free((void *)desc.buffer);
 417                 return -1;
 418         }
 419
 420         tree = parse_tree_indirect(oid);
 421         prime_cache_tree(the_repository->index, tree);
 422
 423         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 424                 ret = error(_("could not write index"));
 425         free((void *)desc.buffer);
 426
 427         if (ret)
 428                 return ret;
 429
 430         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 431         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 432         prefix_len = msg.len;
 433
 434         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 435                 old_orig = &oid_old_orig;
 436         if (!get_oid("HEAD", &oid_orig)) {
 437                 orig = &oid_orig;
 438                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 439                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 440                            UPDATE_REFS_MSG_ON_ERR);
 441         } else if (old_orig)
 442                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 443         strbuf_setlen(&msg, prefix_len);
 444         strbuf_addstr(&msg, "updating HEAD");
 445         if (!switch_to_branch)
 446                 ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 447                                  UPDATE_REFS_MSG_ON_ERR);
 448         else {
 449                 ret = create_symref("HEAD", switch_to_branch, msg.buf);
 450                 if (!ret)
 451                         ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 452                                          UPDATE_REFS_MSG_ON_ERR);
 453         }
 454
 455         strbuf_release(&msg);
 456         return ret;
 457 }
 458
 459 static int rebase_config(const char *var, const char *value, void *data)
 460 {
 461         struct rebase_options *opts = data;
 462
 463         if (!strcmp(var, "rebase.stat")) {
 464                 if (git_config_bool(var, value))
 465                         opts->flags |= REBASE_DIFFSTAT;
 466                 else
 467                         opts->flags &= !REBASE_DIFFSTAT;
 468                 return 0;
 469         }
 470
 471         if (!strcmp(var, "rebase.autosquash")) {
 472                 opts->autosquash = git_config_bool(var, value);
 473                 return 0;
 474         }
 475
 476         if (!strcmp(var, "commit.gpgsign")) {
 477                 free(opts->gpg_sign_opt);
 478                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 479                         xstrdup("-S") : NULL;
 480                 return 0;
 481         }
 482
 483         return git_default_config(var, value, data);
 484 }
 485
 486 /*
 487  * Determines whether the commits in from..to are linear, i.e. contain
 488  * no merge commits. This function *expects* `from` to be an ancestor of
 489  * `to`.
 490  */
 491 static int is_linear_history(struct commit *from, struct commit *to)
 492 {
 493         while (to && to != from) {
 494                 parse_commit(to);
 495                 if (!to->parents)
 496                         return 1;
 497                 if (to->parents->next)
 498                         return 0;
 499                 to = to->parents->item;
 500         }
 501         return 1;
 502 }
 503
 504 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 505                             struct object_id *merge_base)
 506 {
 507         struct commit *head = lookup_commit(the_repository, head_oid);
 508         struct commit_list *merge_bases;
 509         int res;
 510
 511         if (!head)
 512                 return 0;
 513
 514         merge_bases = get_merge_bases(onto, head);
 515         if (merge_bases && !merge_bases->next) {
 516                 oidcpy(merge_base, &merge_bases->item->object.oid);
 517                 res = !oidcmp(merge_base, &onto->object.oid);
 518         } else {
 519                 oidcpy(merge_base, &null_oid);
 520                 res = 0;
 521         }
 522         free_commit_list(merge_bases);
 523         return res && is_linear_history(onto, head);
 524 }
 525
 526 /* -i followed by -m is still -i */
 527 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 528 {
 529         struct rebase_options *opts = opt->value;
 530
 531         if (!is_interactive(opts))
 532                 opts->type = REBASE_MERGE;
 533
 534         return 0;
 535 }
 536
 537 /* -i followed by -p is still explicitly interactive, but -p alone is not */
 538 static int parse_opt_interactive(const struct option *opt, const char *arg,
 539                                  int unset)
 540 {
 541         struct rebase_options *opts = opt->value;
 542
 543         opts->type = REBASE_INTERACTIVE;
 544         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 545
 546         return 0;
 547 }
 548
 549 int cmd_rebase(int argc, const char **argv, const char *prefix)
 550 {
 551         struct rebase_options options = {
 552                 .type = REBASE_UNSPECIFIED,
 553                 .flags = REBASE_NO_QUIET,
 554                 .git_am_opt = STRBUF_INIT,
 555                 .allow_rerere_autoupdate  = -1,
 556         };
 557         const char *branch_name;
 558         int ret, flags, total_argc, in_progress = 0;
 559         int ok_to_skip_pre_rebase = 0;
 560         struct strbuf msg = STRBUF_INIT;
 561         struct strbuf revisions = STRBUF_INIT;
 562         struct strbuf buf = STRBUF_INIT;
 563         struct object_id merge_base;
 564         enum {
 565                 NO_ACTION,
 566                 ACTION_CONTINUE,
 567                 ACTION_SKIP,
 568                 ACTION_ABORT,
 569                 ACTION_QUIT,
 570                 ACTION_EDIT_TODO,
 571                 ACTION_SHOW_CURRENT_PATCH,
 572         } action = NO_ACTION;
 573         int committer_date_is_author_date = 0;
 574         int ignore_date = 0;
 575         int ignore_whitespace = 0;
 576         const char *gpg_sign = NULL;
 577         int opt_c = -1;
 578         struct string_list whitespace = STRING_LIST_INIT_NODUP;
 579         struct option builtin_rebase_options[] = {
 580                 OPT_STRING(0, "onto", &options.onto_name,
 581                            N_("revision"),
 582                            N_("rebase onto given branch instead of upstream")),
 583                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 584                          N_("allow pre-rebase hook to run")),
 585                 OPT_NEGBIT('q', "quiet", &options.flags,
 586                            N_("be quiet. implies --no-stat"),
 587                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 588                 OPT_BIT('v', "verbose", &options.flags,
 589                         N_("display a diffstat of what changed upstream"),
 590                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 591                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 592                         N_("do not show diffstat of what changed upstream"),
 593                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 594                 OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
 595                          N_("passed to 'git apply'")),
 596                 OPT_BOOL(0, "signoff", &options.signoff,
 597                          N_("add a Signed-off-by: line to each commit")),
 598                 OPT_BOOL(0, "committer-date-is-author-date",
 599                          &committer_date_is_author_date,
 600                          N_("passed to 'git am'")),
 601                 OPT_BOOL(0, "ignore-date", &ignore_date,
 602                          N_("passed to 'git am'")),
 603                 OPT_BIT('f', "force-rebase", &options.flags,
 604                         N_("cherry-pick all commits, even if unchanged"),
 605                         REBASE_FORCE),
 606                 OPT_BIT(0, "no-ff", &options.flags,
 607                         N_("cherry-pick all commits, even if unchanged"),
 608                         REBASE_FORCE),
 609                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
 610                             ACTION_CONTINUE),
 611                 OPT_CMDMODE(0, "skip", &action,
 612                             N_("skip current patch and continue"), ACTION_SKIP),
 613                 OPT_CMDMODE(0, "abort", &action,
 614                             N_("abort and check out the original branch"),
 615                             ACTION_ABORT),
 616                 OPT_CMDMODE(0, "quit", &action,
 617                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
 618                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 619                             "during an interactive rebase"), ACTION_EDIT_TODO),
 620                 OPT_CMDMODE(0, "show-current-patch", &action,
 621                             N_("show the patch file being applied or merged"),
 622                             ACTION_SHOW_CURRENT_PATCH),
 623                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 624                         N_("use merging strategies to rebase"),
 625                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 626                         parse_opt_merge },
 627                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 628                         N_("let the user edit the list of commits to rebase"),
 629                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 630                         parse_opt_interactive },
 631                 OPT_SET_INT('p', "preserve-merges", &options.type,
 632                             N_("try to recreate merges instead of ignoring "
 633                                "them"), REBASE_PRESERVE_MERGES),
 634                 OPT_BOOL(0, "rerere-autoupdate",
 635                          &options.allow_rerere_autoupdate,
 636                          N_("allow rerere to update index  with resolved "
 637                             "conflict")),
 638                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
 639                          N_("preserve empty commits during rebase")),
 640                 OPT_BOOL(0, "autosquash", &options.autosquash,
 641                          N_("move commits that begin with "
 642                             "squash!/fixup! under -i")),
 643                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 644                         N_("GPG-sign commits"),
 645                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 646                 OPT_STRING_LIST(0, "whitespace", &whitespace,
 647                                 N_("whitespace"), N_("passed to 'git apply'")),
 648                 OPT_SET_INT('C', NULL, &opt_c, N_("passed to 'git apply'"),
 649                             REBASE_AM),
 650                 OPT_END(),
 651         };
 652
 653         /*
 654          * NEEDSWORK: Once the builtin rebase has been tested enough
 655          * and git-legacy-rebase.sh is retired to contrib/, this preamble
 656          * can be removed.
 657          */
 658
 659         if (!use_builtin_rebase()) {
 660                 const char *path = mkpath("%s/git-legacy-rebase",
 661                                           git_exec_path());
 662
 663                 if (sane_execvp(path, (char **)argv) < 0)
 664                         die_errno(_("could not exec %s"), path);
 665                 else
 666                         BUG("sane_execvp() returned???");
 667         }
 668
 669         if (argc == 2 && !strcmp(argv[1], "-h"))
 670                 usage_with_options(builtin_rebase_usage,
 671                                    builtin_rebase_options);
 672
 673         prefix = setup_git_directory();
 674         trace_repo_setup(prefix);
 675         setup_work_tree();
 676
 677         git_config(rebase_config, &options);
 678
 679         strbuf_reset(&buf);
 680         strbuf_addf(&buf, "%s/applying", apply_dir());
 681         if(file_exists(buf.buf))
 682                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
 683
 684         if (is_directory(apply_dir())) {
 685                 options.type = REBASE_AM;
 686                 options.state_dir = apply_dir();
 687         } else if (is_directory(merge_dir())) {
 688                 strbuf_reset(&buf);
 689                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
 690                 if (is_directory(buf.buf)) {
 691                         options.type = REBASE_PRESERVE_MERGES;
 692                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 693                 } else {
 694                         strbuf_reset(&buf);
 695                         strbuf_addf(&buf, "%s/interactive", merge_dir());
 696                         if(file_exists(buf.buf)) {
 697                                 options.type = REBASE_INTERACTIVE;
 698                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 699                         } else
 700                                 options.type = REBASE_MERGE;
 701                 }
 702                 options.state_dir = merge_dir();
 703         }
 704
 705         if (options.type != REBASE_UNSPECIFIED)
 706                 in_progress = 1;
 707
 708         total_argc = argc;
 709         argc = parse_options(argc, argv, prefix,
 710                              builtin_rebase_options,
 711                              builtin_rebase_usage, 0);
 712
 713         if (action != NO_ACTION && total_argc != 2) {
 714                 usage_with_options(builtin_rebase_usage,
 715                                    builtin_rebase_options);
 716         }
 717
 718         if (argc > 2)
 719                 usage_with_options(builtin_rebase_usage,
 720                                    builtin_rebase_options);
 721
 722         if (action != NO_ACTION && !in_progress)
 723                 die(_("No rebase in progress?"));
 724
 725         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 726                 die(_("The --edit-todo action can only be used during "
 727                       "interactive rebase."));
 728
 729         switch (action) {
 730         case ACTION_CONTINUE: {
 731                 struct object_id head;
 732                 struct lock_file lock_file = LOCK_INIT;
 733                 int fd;
 734
 735                 options.action = "continue";
 736
 737                 /* Sanity check */
 738                 if (get_oid("HEAD", &head))
 739                         die(_("Cannot read HEAD"));
 740
 741                 fd = hold_locked_index(&lock_file, 0);
 742                 if (read_index(the_repository->index) < 0)
 743                         die(_("could not read index"));
 744                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
 745                               NULL);
 746                 if (0 <= fd)
 747                         update_index_if_able(the_repository->index,
 748                                              &lock_file);
 749                 rollback_lock_file(&lock_file);
 750
 751                 if (has_unstaged_changes(1)) {
 752                         puts(_("You must edit all merge conflicts and then\n"
 753                                "mark them as resolved using git add"));
 754                         exit(1);
 755                 }
 756                 if (read_basic_state(&options))
 757                         exit(1);
 758                 goto run_rebase;
 759         }
 760         case ACTION_SKIP: {
 761                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 762
 763                 options.action = "skip";
 764
 765                 rerere_clear(&merge_rr);
 766                 string_list_clear(&merge_rr, 1);
 767
 768                 if (reset_head(NULL, "reset", NULL, 0) < 0)
 769                         die(_("could not discard worktree changes"));
 770                 if (read_basic_state(&options))
 771                         exit(1);
 772                 goto run_rebase;
 773         }
 774         case ACTION_ABORT: {
 775                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 776                 options.action = "abort";
 777
 778                 rerere_clear(&merge_rr);
 779                 string_list_clear(&merge_rr, 1);
 780
 781                 if (read_basic_state(&options))
 782                         exit(1);
 783                 if (reset_head(&options.orig_head, "reset",
 784                                options.head_name, 0) < 0)
 785                         die(_("could not move back to %s"),
 786                             oid_to_hex(&options.orig_head));
 787                 ret = finish_rebase(&options);
 788                 goto cleanup;
 789         }
 790         case ACTION_QUIT: {
 791                 strbuf_reset(&buf);
 792                 strbuf_addstr(&buf, options.state_dir);
 793                 ret = !!remove_dir_recursively(&buf, 0);
 794                 if (ret)
 795                         die(_("could not remove '%s'"), options.state_dir);
 796                 goto cleanup;
 797         }
 798         case ACTION_EDIT_TODO:
 799                 options.action = "edit-todo";
 800                 options.dont_finish_rebase = 1;
 801                 goto run_rebase;
 802         case ACTION_SHOW_CURRENT_PATCH:
 803                 options.action = "show-current-patch";
 804                 options.dont_finish_rebase = 1;
 805                 goto run_rebase;
 806         case NO_ACTION:
 807                 break;
 808         default:
 809                 BUG("action: %d", action);
 810         }
 811
 812         /* Make sure no rebase is in progress */
 813         if (in_progress) {
 814                 const char *last_slash = strrchr(options.state_dir, '/');
 815                 const char *state_dir_base =
 816                         last_slash ? last_slash + 1 : options.state_dir;
 817                 const char *cmd_live_rebase =
 818                         "git rebase (--continue | --abort | --skip)";
 819                 strbuf_reset(&buf);
 820                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
 821                 die(_("It seems that there is already a %s directory, and\n"
 822                       "I wonder if you are in the middle of another rebase.  "
 823                       "If that is the\n"
 824                       "case, please try\n\t%s\n"
 825                       "If that is not the case, please\n\t%s\n"
 826                       "and run me again.  I am stopping in case you still "
 827                       "have something\n"
 828                       "valuable there.\n"),
 829                     state_dir_base, cmd_live_rebase, buf.buf);
 830         }
 831
 832         if (!(options.flags & REBASE_NO_QUIET))
 833                 strbuf_addstr(&options.git_am_opt, " -q");
 834
 835         if (committer_date_is_author_date) {
 836                 strbuf_addstr(&options.git_am_opt,
 837                               " --committer-date-is-author-date");
 838                 options.flags |= REBASE_FORCE;
 839         }
 840
 841         if (ignore_whitespace)
 842                 strbuf_addstr(&options.git_am_opt, " --ignore-whitespace");
 843
 844         if (ignore_date) {
 845                 strbuf_addstr(&options.git_am_opt, " --ignore-date");
 846                 options.flags |= REBASE_FORCE;
 847         }
 848
 849         if (options.keep_empty)
 850                 imply_interactive(&options, "--keep-empty");
 851
 852         if (gpg_sign) {
 853                 free(options.gpg_sign_opt);
 854                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
 855         }
 856
 857         if (opt_c >= 0)
 858                 strbuf_addf(&options.git_am_opt, " -C%d", opt_c);
 859
 860         if (whitespace.nr) {
 861                 int i;
 862
 863                 for (i = 0; i < whitespace.nr; i++) {
 864                         const char *item = whitespace.items[i].string;
 865
 866                         strbuf_addf(&options.git_am_opt, " --whitespace=%s",
 867                                     item);
 868
 869                         if ((!strcmp(item, "fix")) || (!strcmp(item, "strip")))
 870                                 options.flags |= REBASE_FORCE;
 871                 }
 872         }
 873
 874         switch (options.type) {
 875         case REBASE_MERGE:
 876         case REBASE_INTERACTIVE:
 877         case REBASE_PRESERVE_MERGES:
 878                 options.state_dir = merge_dir();
 879                 break;
 880         case REBASE_AM:
 881                 options.state_dir = apply_dir();
 882                 break;
 883         default:
 884                 /* the default rebase backend is `--am` */
 885                 options.type = REBASE_AM;
 886                 options.state_dir = apply_dir();
 887                 break;
 888         }
 889
 890         if (options.signoff) {
 891                 if (options.type == REBASE_PRESERVE_MERGES)
 892                         die("cannot combine '--signoff' with "
 893                             "'--preserve-merges'");
 894                 strbuf_addstr(&options.git_am_opt, " --signoff");
 895                 options.flags |= REBASE_FORCE;
 896         }
 897
 898         if (!options.root) {
 899                 if (argc < 1)
 900                         die("TODO: handle @{upstream}");
 901                 else {
 902                         options.upstream_name = argv[0];
 903                         argc--;
 904                         argv++;
 905                         if (!strcmp(options.upstream_name, "-"))
 906                                 options.upstream_name = "@{-1}";
 907                 }
 908                 options.upstream = peel_committish(options.upstream_name);
 909                 if (!options.upstream)
 910                         die(_("invalid upstream '%s'"), options.upstream_name);
 911                 options.upstream_arg = options.upstream_name;
 912         } else
 913                 die("TODO: upstream for --root");
 914
 915         /* Make sure the branch to rebase onto is valid. */
 916         if (!options.onto_name)
 917                 options.onto_name = options.upstream_name;
 918         if (strstr(options.onto_name, "...")) {
 919                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
 920                         die(_("'%s': need exactly one merge base"),
 921                             options.onto_name);
 922                 options.onto = lookup_commit_or_die(&merge_base,
 923                                                     options.onto_name);
 924         } else {
 925                 options.onto = peel_committish(options.onto_name);
 926                 if (!options.onto)
 927                         die(_("Does not point to a valid commit '%s'"),
 928                                 options.onto_name);
 929         }
 930
 931         /*
 932          * If the branch to rebase is given, that is the branch we will rebase
 933          * branch_name -- branch/commit being rebased, or
 934          *                HEAD (already detached)
 935          * orig_head -- commit object name of tip of the branch before rebasing
 936          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
 937          */
 938         if (argc == 1) {
 939                 /* Is it "rebase other branchname" or "rebase other commit"? */
 940                 branch_name = argv[0];
 941                 options.switch_to = argv[0];
 942
 943                 /* Is it a local branch? */
 944                 strbuf_reset(&buf);
 945                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
 946                 if (!read_ref(buf.buf, &options.orig_head))
 947                         options.head_name = xstrdup(buf.buf);
 948                 /* If not is it a valid ref (branch or commit)? */
 949                 else if (!get_oid(branch_name, &options.orig_head))
 950                         options.head_name = NULL;
 951                 else
 952                         die(_("fatal: no such branch/commit '%s'"),
 953                             branch_name);
 954         } else if (argc == 0) {
 955                 /* Do not need to switch branches, we are already on it. */
 956                 options.head_name =
 957                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 958                                          &flags));
 959                 if (!options.head_name)
 960                         die(_("No such ref: %s"), "HEAD");
 961                 if (flags & REF_ISSYMREF) {
 962                         if (!skip_prefix(options.head_name,
 963                                          "refs/heads/", &branch_name))
 964                                 branch_name = options.head_name;
 965
 966                 } else {
 967                         free(options.head_name);
 968                         options.head_name = NULL;
 969                         branch_name = "HEAD";
 970                 }
 971                 if (get_oid("HEAD", &options.orig_head))
 972                         die(_("Could not resolve HEAD to a revision"));
 973         } else
 974                 BUG("unexpected number of arguments left to parse");
 975
 976         if (read_index(the_repository->index) < 0)
 977                 die(_("could not read index"));
 978
 979         if (require_clean_work_tree("rebase",
 980                                     _("Please commit or stash them."), 1, 1)) {
 981                 ret = 1;
 982                 goto cleanup;
 983         }
 984
 985         /*
 986          * Now we are rebasing commits upstream..orig_head (or with --root,
 987          * everything leading up to orig_head) on top of onto.
 988          */
 989
 990         /*
 991          * Check if we are already based on onto with linear history,
 992          * but this should be done only when upstream and onto are the same
 993          * and if this is not an interactive rebase.
 994          */
 995         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
 996             !is_interactive(&options) && !options.restrict_revision &&
 997             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
 998                 int flag;
 999
1000                 if (!(options.flags & REBASE_FORCE)) {
1001                         /* Lazily switch to the target branch if needed... */
1002                         if (options.switch_to) {
1003                                 struct object_id oid;
1004
1005                                 if (get_oid(options.switch_to, &oid) < 0) {
1006                                         ret = !!error(_("could not parse '%s'"),
1007                                                       options.switch_to);
1008                                         goto cleanup;
1009                                 }
1010
1011                                 strbuf_reset(&buf);
1012                                 strbuf_addf(&buf, "rebase: checkout %s",
1013                                             options.switch_to);
1014                                 if (reset_head(&oid, "checkout",
1015                                                options.head_name, 0) < 0) {
1016                                         ret = !!error(_("could not switch to "
1017                                                         "%s"),
1018                                                       options.switch_to);
1019                                         goto cleanup;
1020                                 }
1021                         }
1022
1023                         if (!(options.flags & REBASE_NO_QUIET))
1024                                 ; /* be quiet */
1025                         else if (!strcmp(branch_name, "HEAD") &&
1026                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1027                                 puts(_("HEAD is up to date."));
1028                         else
1029                                 printf(_("Current branch %s is up to date.\n"),
1030                                        branch_name);
1031                         ret = !!finish_rebase(&options);
1032                         goto cleanup;
1033                 } else if (!(options.flags & REBASE_NO_QUIET))
1034                         ; /* be quiet */
1035                 else if (!strcmp(branch_name, "HEAD") &&
1036                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1037                         puts(_("HEAD is up to date, rebase forced."));
1038                 else
1039                         printf(_("Current branch %s is up to date, rebase "
1040                                  "forced.\n"), branch_name);
1041         }
1042
1043         /* If a hook exists, give it a chance to interrupt*/
1044         if (!ok_to_skip_pre_rebase &&
1045             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1046                         argc ? argv[0] : NULL, NULL))
1047                 die(_("The pre-rebase hook refused to rebase."));
1048
1049         if (options.flags & REBASE_DIFFSTAT) {
1050                 struct diff_options opts;
1051
1052                 if (options.flags & REBASE_VERBOSE)
1053                         printf(_("Changes from %s to %s:\n"),
1054                                 oid_to_hex(&merge_base),
1055                                 oid_to_hex(&options.onto->object.oid));
1056
1057                 /* We want color (if set), but no pager */
1058                 diff_setup(&opts);
1059                 opts.stat_width = -1; /* use full terminal width */
1060                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1061                 opts.output_format |=
1062                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1063                 opts.detect_rename = DIFF_DETECT_RENAME;
1064                 diff_setup_done(&opts);
1065                 diff_tree_oid(&merge_base, &options.onto->object.oid,
1066                               "", &opts);
1067                 diffcore_std(&opts);
1068                 diff_flush(&opts);
1069         }
1070
1071         if (is_interactive(&options))
1072                 goto run_rebase;
1073
1074         /* Detach HEAD and reset the tree */
1075         if (options.flags & REBASE_NO_QUIET)
1076                 printf(_("First, rewinding head to replay your work on top of "
1077                          "it...\n"));
1078
1079         strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
1080         if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
1081                 die(_("Could not detach HEAD"));
1082         strbuf_release(&msg);
1083
1084         strbuf_addf(&revisions, "%s..%s",
1085                     options.root ? oid_to_hex(&options.onto->object.oid) :
1086                     (options.restrict_revision ?
1087                      oid_to_hex(&options.restrict_revision->object.oid) :
1088                      oid_to_hex(&options.upstream->object.oid)),
1089                     oid_to_hex(&options.orig_head));
1090
1091         options.revisions = revisions.buf;
1092
1093 run_rebase:
1094         ret = !!run_specific_rebase(&options);
1095
1096 cleanup:
1097         strbuf_release(&revisions);
1098         free(options.head_name);
1099         free(options.gpg_sign_opt);
1100         return ret;
1101 }