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