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 "commit-reach.h"
  25 #include "rerere.h"
  26
  27 static char const * const builtin_rebase_usage[] = {
  28         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  29                 "[<upstream>] [<branch>]"),
  30         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  31                 "--root [<branch>]"),
  32         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  33         NULL
  34 };
  35
  36 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  37 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  38
  39 enum rebase_type {
  40         REBASE_UNSPECIFIED = -1,
  41         REBASE_AM,
  42         REBASE_MERGE,
  43         REBASE_INTERACTIVE,
  44         REBASE_PRESERVE_MERGES
  45 };
  46
  47 static int use_builtin_rebase(void)
  48 {
  49         struct child_process cp = CHILD_PROCESS_INIT;
  50         struct strbuf out = STRBUF_INIT;
  51         int ret;
  52
  53         argv_array_pushl(&cp.args,
  54                          "config", "--bool", "rebase.usebuiltin", NULL);
  55         cp.git_cmd = 1;
  56         if (capture_command(&cp, &out, 6)) {
  57                 strbuf_release(&out);
  58                 return 1;
  59         }
  60
  61         strbuf_trim(&out);
  62         ret = !strcmp("true", out.buf);
  63         strbuf_release(&out);
  64         return ret;
  65 }
  66
  67 struct rebase_options {
  68         enum rebase_type type;
  69         const char *state_dir;
  70         struct commit *upstream;
  71         const char *upstream_name;
  72         const char *upstream_arg;
  73         char *head_name;
  74         struct object_id orig_head;
  75         struct commit *onto;
  76         const char *onto_name;
  77         const char *revisions;
  78         const char *switch_to;
  79         int root;
  80         struct object_id *squash_onto;
  81         struct commit *restrict_revision;
  82         int dont_finish_rebase;
  83         enum {
  84                 REBASE_NO_QUIET = 1<<0,
  85                 REBASE_VERBOSE = 1<<1,
  86                 REBASE_DIFFSTAT = 1<<2,
  87                 REBASE_FORCE = 1<<3,
  88                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  89         } flags;
  90         struct argv_array git_am_opts;
  91         const char *action;
  92         int signoff;
  93         int allow_rerere_autoupdate;
  94         int keep_empty;
  95         int autosquash;
  96         char *gpg_sign_opt;
  97         int autostash;
  98         char *cmd;
  99         int allow_empty_message;
 100         int rebase_merges, rebase_cousins;
 101         char *strategy, *strategy_opts;
 102         struct strbuf git_format_patch_opt;
 103 };
 104
 105 static int is_interactive(struct rebase_options *opts)
 106 {
 107         return opts->type == REBASE_INTERACTIVE ||
 108                 opts->type == REBASE_PRESERVE_MERGES;
 109 }
 110
 111 static void imply_interactive(struct rebase_options *opts, const char *option)
 112 {
 113         switch (opts->type) {
 114         case REBASE_AM:
 115                 die(_("%s requires an interactive rebase"), option);
 116                 break;
 117         case REBASE_INTERACTIVE:
 118         case REBASE_PRESERVE_MERGES:
 119                 break;
 120         case REBASE_MERGE:
 121                 /* we silently *upgrade* --merge to --interactive if needed */
 122         default:
 123                 opts->type = REBASE_INTERACTIVE; /* implied */
 124                 break;
 125         }
 126 }
 127
 128 /* Returns the filename prefixed by the state_dir */
 129 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 130 {
 131         static struct strbuf path = STRBUF_INIT;
 132         static size_t prefix_len;
 133
 134         if (!prefix_len) {
 135                 strbuf_addf(&path, "%s/", opts->state_dir);
 136                 prefix_len = path.len;
 137         }
 138
 139         strbuf_setlen(&path, prefix_len);
 140         strbuf_addstr(&path, filename);
 141         return path.buf;
 142 }
 143
 144 /* Read one file, then strip line endings */
 145 static int read_one(const char *path, struct strbuf *buf)
 146 {
 147         if (strbuf_read_file(buf, path, 0) < 0)
 148                 return error_errno(_("could not read '%s'"), path);
 149         strbuf_trim_trailing_newline(buf);
 150         return 0;
 151 }
 152
 153 /* Initialize the rebase options from the state directory. */
 154 static int read_basic_state(struct rebase_options *opts)
 155 {
 156         struct strbuf head_name = STRBUF_INIT;
 157         struct strbuf buf = STRBUF_INIT;
 158         struct object_id oid;
 159
 160         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 161             read_one(state_dir_path("onto", opts), &buf))
 162                 return -1;
 163         opts->head_name = starts_with(head_name.buf, "refs/") ?
 164                 xstrdup(head_name.buf) : NULL;
 165         strbuf_release(&head_name);
 166         if (get_oid(buf.buf, &oid))
 167                 return error(_("could not get 'onto': '%s'"), buf.buf);
 168         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 169
 170         /*
 171          * We always write to orig-head, but interactive rebase used to write to
 172          * head. Fall back to reading from head to cover for the case that the
 173          * user upgraded git with an ongoing interactive rebase.
 174          */
 175         strbuf_reset(&buf);
 176         if (file_exists(state_dir_path("orig-head", opts))) {
 177                 if (read_one(state_dir_path("orig-head", opts), &buf))
 178                         return -1;
 179         } else if (read_one(state_dir_path("head", opts), &buf))
 180                 return -1;
 181         if (get_oid(buf.buf, &opts->orig_head))
 182                 return error(_("invalid orig-head: '%s'"), buf.buf);
 183
 184         strbuf_reset(&buf);
 185         if (read_one(state_dir_path("quiet", opts), &buf))
 186                 return -1;
 187         if (buf.len)
 188                 opts->flags &= ~REBASE_NO_QUIET;
 189         else
 190                 opts->flags |= REBASE_NO_QUIET;
 191
 192         if (file_exists(state_dir_path("verbose", opts)))
 193                 opts->flags |= REBASE_VERBOSE;
 194
 195         if (file_exists(state_dir_path("signoff", opts))) {
 196                 opts->signoff = 1;
 197                 opts->flags |= REBASE_FORCE;
 198         }
 199
 200         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 201                 strbuf_reset(&buf);
 202                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 203                             &buf))
 204                         return -1;
 205                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 206                         opts->allow_rerere_autoupdate = 1;
 207                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 208                         opts->allow_rerere_autoupdate = 0;
 209                 else
 210                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 211                                   "'%s'"), buf.buf);
 212         } else
 213                 opts->allow_rerere_autoupdate = -1;
 214
 215         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 216                 strbuf_reset(&buf);
 217                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 218                             &buf))
 219                         return -1;
 220                 free(opts->gpg_sign_opt);
 221                 opts->gpg_sign_opt = xstrdup(buf.buf);
 222         }
 223
 224         if (file_exists(state_dir_path("strategy", opts))) {
 225                 strbuf_reset(&buf);
 226                 if (read_one(state_dir_path("strategy", opts), &buf))
 227                         return -1;
 228                 free(opts->strategy);
 229                 opts->strategy = xstrdup(buf.buf);
 230         }
 231
 232         if (file_exists(state_dir_path("strategy_opts", opts))) {
 233                 strbuf_reset(&buf);
 234                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 235                         return -1;
 236                 free(opts->strategy_opts);
 237                 opts->strategy_opts = xstrdup(buf.buf);
 238         }
 239
 240         strbuf_release(&buf);
 241
 242         return 0;
 243 }
 244
 245 static int apply_autostash(struct rebase_options *opts)
 246 {
 247         const char *path = state_dir_path("autostash", opts);
 248         struct strbuf autostash = STRBUF_INIT;
 249         struct child_process stash_apply = CHILD_PROCESS_INIT;
 250
 251         if (!file_exists(path))
 252                 return 0;
 253
 254         if (read_one(path, &autostash))
 255                 return error(_("Could not read '%s'"), path);
 256         /* Ensure that the hash is not mistaken for a number */
 257         strbuf_addstr(&autostash, "^0");
 258         argv_array_pushl(&stash_apply.args,
 259                          "stash", "apply", autostash.buf, NULL);
 260         stash_apply.git_cmd = 1;
 261         stash_apply.no_stderr = stash_apply.no_stdout =
 262                 stash_apply.no_stdin = 1;
 263         if (!run_command(&stash_apply))
 264                 printf(_("Applied autostash.\n"));
 265         else {
 266                 struct argv_array args = ARGV_ARRAY_INIT;
 267                 int res = 0;
 268
 269                 argv_array_pushl(&args,
 270                                  "stash", "store", "-m", "autostash", "-q",
 271                                  autostash.buf, NULL);
 272                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 273                         res = error(_("Cannot store %s"), autostash.buf);
 274                 argv_array_clear(&args);
 275                 strbuf_release(&autostash);
 276                 if (res)
 277                         return res;
 278
 279                 fprintf(stderr,
 280                         _("Applying autostash resulted in conflicts.\n"
 281                           "Your changes are safe in the stash.\n"
 282                           "You can run \"git stash pop\" or \"git stash drop\" "
 283                           "at any time.\n"));
 284         }
 285
 286         strbuf_release(&autostash);
 287         return 0;
 288 }
 289
 290 static int finish_rebase(struct rebase_options *opts)
 291 {
 292         struct strbuf dir = STRBUF_INIT;
 293         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 294
 295         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 296         apply_autostash(opts);
 297         close_all_packs(the_repository->objects);
 298         /*
 299          * We ignore errors in 'gc --auto', since the
 300          * user should see them.
 301          */
 302         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 303         strbuf_addstr(&dir, opts->state_dir);
 304         remove_dir_recursively(&dir, 0);
 305         strbuf_release(&dir);
 306
 307         return 0;
 308 }
 309
 310 static struct commit *peel_committish(const char *name)
 311 {
 312         struct object *obj;
 313         struct object_id oid;
 314
 315         if (get_oid(name, &oid))
 316                 return NULL;
 317         obj = parse_object(the_repository, &oid);
 318         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 319 }
 320
 321 static void add_var(struct strbuf *buf, const char *name, const char *value)
 322 {
 323         if (!value)
 324                 strbuf_addf(buf, "unset %s; ", name);
 325         else {
 326                 strbuf_addf(buf, "%s=", name);
 327                 sq_quote_buf(buf, value);
 328                 strbuf_addstr(buf, "; ");
 329         }
 330 }
 331
 332 static const char *resolvemsg =
 333 N_("Resolve all conflicts manually, mark them as resolved with\n"
 334 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 335 "You can instead skip this commit: run \"git rebase --skip\".\n"
 336 "To abort and get back to the state before \"git rebase\", run "
 337 "\"git rebase --abort\".");
 338
 339 static int run_specific_rebase(struct rebase_options *opts)
 340 {
 341         const char *argv[] = { NULL, NULL };
 342         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
 343         int status;
 344         const char *backend, *backend_func;
 345
 346         if (opts->type == REBASE_INTERACTIVE) {
 347                 /* Run builtin interactive rebase */
 348                 struct child_process child = CHILD_PROCESS_INIT;
 349
 350                 argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 351                                  resolvemsg);
 352                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 353                         argv_array_push(&child.env_array, "GIT_EDITOR=:");
 354                         opts->autosquash = 0;
 355                 }
 356
 357                 child.git_cmd = 1;
 358                 argv_array_push(&child.args, "rebase--interactive");
 359
 360                 if (opts->action)
 361                         argv_array_pushf(&child.args, "--%s", opts->action);
 362                 if (opts->keep_empty)
 363                         argv_array_push(&child.args, "--keep-empty");
 364                 if (opts->rebase_merges)
 365                         argv_array_push(&child.args, "--rebase-merges");
 366                 if (opts->rebase_cousins)
 367                         argv_array_push(&child.args, "--rebase-cousins");
 368                 if (opts->autosquash)
 369                         argv_array_push(&child.args, "--autosquash");
 370                 if (opts->flags & REBASE_VERBOSE)
 371                         argv_array_push(&child.args, "--verbose");
 372                 if (opts->flags & REBASE_FORCE)
 373                         argv_array_push(&child.args, "--no-ff");
 374                 if (opts->restrict_revision)
 375                         argv_array_pushf(&child.args,
 376                                          "--restrict-revision=^%s",
 377                                          oid_to_hex(&opts->restrict_revision->object.oid));
 378                 if (opts->upstream)
 379                         argv_array_pushf(&child.args, "--upstream=%s",
 380                                          oid_to_hex(&opts->upstream->object.oid));
 381                 if (opts->onto)
 382                         argv_array_pushf(&child.args, "--onto=%s",
 383                                          oid_to_hex(&opts->onto->object.oid));
 384                 if (opts->squash_onto)
 385                         argv_array_pushf(&child.args, "--squash-onto=%s",
 386                                          oid_to_hex(opts->squash_onto));
 387                 if (opts->onto_name)
 388                         argv_array_pushf(&child.args, "--onto-name=%s",
 389                                          opts->onto_name);
 390                 argv_array_pushf(&child.args, "--head-name=%s",
 391                                  opts->head_name ?
 392                                  opts->head_name : "detached HEAD");
 393                 if (opts->strategy)
 394                         argv_array_pushf(&child.args, "--strategy=%s",
 395                                          opts->strategy);
 396                 if (opts->strategy_opts)
 397                         argv_array_pushf(&child.args, "--strategy-opts=%s",
 398                                          opts->strategy_opts);
 399                 if (opts->switch_to)
 400                         argv_array_pushf(&child.args, "--switch-to=%s",
 401                                          opts->switch_to);
 402                 if (opts->cmd)
 403                         argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
 404                 if (opts->allow_empty_message)
 405                         argv_array_push(&child.args, "--allow-empty-message");
 406                 if (opts->allow_rerere_autoupdate > 0)
 407                         argv_array_push(&child.args, "--rerere-autoupdate");
 408                 else if (opts->allow_rerere_autoupdate == 0)
 409                         argv_array_push(&child.args, "--no-rerere-autoupdate");
 410                 if (opts->gpg_sign_opt)
 411                         argv_array_push(&child.args, opts->gpg_sign_opt);
 412                 if (opts->signoff)
 413                         argv_array_push(&child.args, "--signoff");
 414
 415                 status = run_command(&child);
 416                 goto finished_rebase;
 417         }
 418
 419         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 420         add_var(&script_snippet, "state_dir", opts->state_dir);
 421
 422         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 423         add_var(&script_snippet, "upstream", opts->upstream ?
 424                 oid_to_hex(&opts->upstream->object.oid) : NULL);
 425         add_var(&script_snippet, "head_name",
 426                 opts->head_name ? opts->head_name : "detached HEAD");
 427         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 428         add_var(&script_snippet, "onto", opts->onto ?
 429                 oid_to_hex(&opts->onto->object.oid) : NULL);
 430         add_var(&script_snippet, "onto_name", opts->onto_name);
 431         add_var(&script_snippet, "revisions", opts->revisions);
 432         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 433                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 434         add_var(&script_snippet, "GIT_QUIET",
 435                 opts->flags & REBASE_NO_QUIET ? "" : "t");
 436         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
 437         add_var(&script_snippet, "git_am_opt", buf.buf);
 438         strbuf_release(&buf);
 439         add_var(&script_snippet, "verbose",
 440                 opts->flags & REBASE_VERBOSE ? "t" : "");
 441         add_var(&script_snippet, "diffstat",
 442                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
 443         add_var(&script_snippet, "force_rebase",
 444                 opts->flags & REBASE_FORCE ? "t" : "");
 445         if (opts->switch_to)
 446                 add_var(&script_snippet, "switch_to", opts->switch_to);
 447         add_var(&script_snippet, "action", opts->action ? opts->action : "");
 448         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 449         add_var(&script_snippet, "allow_rerere_autoupdate",
 450                 opts->allow_rerere_autoupdate < 0 ? "" :
 451                 opts->allow_rerere_autoupdate ?
 452                 "--rerere-autoupdate" : "--no-rerere-autoupdate");
 453         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 454         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 455         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 456         add_var(&script_snippet, "cmd", opts->cmd);
 457         add_var(&script_snippet, "allow_empty_message",
 458                 opts->allow_empty_message ?  "--allow-empty-message" : "");
 459         add_var(&script_snippet, "rebase_merges",
 460                 opts->rebase_merges ? "t" : "");
 461         add_var(&script_snippet, "rebase_cousins",
 462                 opts->rebase_cousins ? "t" : "");
 463         add_var(&script_snippet, "strategy", opts->strategy);
 464         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 465         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 466         add_var(&script_snippet, "squash_onto",
 467                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 468         add_var(&script_snippet, "git_format_patch_opt",
 469                 opts->git_format_patch_opt.buf);
 470
 471         if (is_interactive(opts) &&
 472             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 473                 strbuf_addstr(&script_snippet,
 474                               "GIT_EDITOR=:; export GIT_EDITOR; ");
 475                 opts->autosquash = 0;
 476         }
 477
 478         switch (opts->type) {
 479         case REBASE_AM:
 480                 backend = "git-rebase--am";
 481                 backend_func = "git_rebase__am";
 482                 break;
 483         case REBASE_MERGE:
 484                 backend = "git-rebase--merge";
 485                 backend_func = "git_rebase__merge";
 486                 break;
 487         case REBASE_PRESERVE_MERGES:
 488                 backend = "git-rebase--preserve-merges";
 489                 backend_func = "git_rebase__preserve_merges";
 490                 break;
 491         default:
 492                 BUG("Unhandled rebase type %d", opts->type);
 493                 break;
 494         }
 495
 496         strbuf_addf(&script_snippet,
 497                     ". git-sh-setup && . git-rebase--common &&"
 498                     " . %s && %s", backend, backend_func);
 499         argv[0] = script_snippet.buf;
 500
 501         status = run_command_v_opt(argv, RUN_USING_SHELL);
 502 finished_rebase:
 503         if (opts->dont_finish_rebase)
 504                 ; /* do nothing */
 505         else if (opts->type == REBASE_INTERACTIVE)
 506                 ; /* interactive rebase cleans up after itself */
 507         else if (status == 0) {
 508                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 509                         finish_rebase(opts);
 510         } else if (status == 2) {
 511                 struct strbuf dir = STRBUF_INIT;
 512
 513                 apply_autostash(opts);
 514                 strbuf_addstr(&dir, opts->state_dir);
 515                 remove_dir_recursively(&dir, 0);
 516                 strbuf_release(&dir);
 517                 die("Nothing to do");
 518         }
 519
 520         strbuf_release(&script_snippet);
 521
 522         return status ? -1 : 0;
 523 }
 524
 525 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 526
 527 static int reset_head(struct object_id *oid, const char *action,
 528                       const char *switch_to_branch, int detach_head,
 529                       const char *reflog_orig_head, const char *reflog_head)
 530 {
 531         struct object_id head_oid;
 532         struct tree_desc desc;
 533         struct lock_file lock = LOCK_INIT;
 534         struct unpack_trees_options unpack_tree_opts;
 535         struct tree *tree;
 536         const char *reflog_action;
 537         struct strbuf msg = STRBUF_INIT;
 538         size_t prefix_len;
 539         struct object_id *orig = NULL, oid_orig,
 540                 *old_orig = NULL, oid_old_orig;
 541         int ret = 0;
 542
 543         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 544                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 545
 546         if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 547                 return -1;
 548
 549         if (!oid) {
 550                 if (get_oid("HEAD", &head_oid)) {
 551                         rollback_lock_file(&lock);
 552                         return error(_("could not determine HEAD revision"));
 553                 }
 554                 oid = &head_oid;
 555         }
 556
 557         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 558         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 559         unpack_tree_opts.head_idx = 1;
 560         unpack_tree_opts.src_index = the_repository->index;
 561         unpack_tree_opts.dst_index = the_repository->index;
 562         unpack_tree_opts.fn = oneway_merge;
 563         unpack_tree_opts.update = 1;
 564         unpack_tree_opts.merge = 1;
 565         if (!detach_head)
 566                 unpack_tree_opts.reset = 1;
 567
 568         if (read_index_unmerged(the_repository->index) < 0) {
 569                 rollback_lock_file(&lock);
 570                 return error(_("could not read index"));
 571         }
 572
 573         if (!fill_tree_descriptor(&desc, oid)) {
 574                 error(_("failed to find tree of %s"), oid_to_hex(oid));
 575                 rollback_lock_file(&lock);
 576                 free((void *)desc.buffer);
 577                 return -1;
 578         }
 579
 580         if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 581                 rollback_lock_file(&lock);
 582                 free((void *)desc.buffer);
 583                 return -1;
 584         }
 585
 586         tree = parse_tree_indirect(oid);
 587         prime_cache_tree(the_repository->index, tree);
 588
 589         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 590                 ret = error(_("could not write index"));
 591         free((void *)desc.buffer);
 592
 593         if (ret)
 594                 return ret;
 595
 596         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 597         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 598         prefix_len = msg.len;
 599
 600         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 601                 old_orig = &oid_old_orig;
 602         if (!get_oid("HEAD", &oid_orig)) {
 603                 orig = &oid_orig;
 604                 if (!reflog_orig_head) {
 605                         strbuf_addstr(&msg, "updating ORIG_HEAD");
 606                         reflog_orig_head = msg.buf;
 607                 }
 608                 update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
 609                            UPDATE_REFS_MSG_ON_ERR);
 610         } else if (old_orig)
 611                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 612         if (!reflog_head) {
 613                 strbuf_setlen(&msg, prefix_len);
 614                 strbuf_addstr(&msg, "updating HEAD");
 615                 reflog_head = msg.buf;
 616         }
 617         if (!switch_to_branch)
 618                 ret = update_ref(reflog_head, "HEAD", oid, orig, REF_NO_DEREF,
 619                                  UPDATE_REFS_MSG_ON_ERR);
 620         else {
 621                 ret = create_symref("HEAD", switch_to_branch, msg.buf);
 622                 if (!ret)
 623                         ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 624                                          UPDATE_REFS_MSG_ON_ERR);
 625         }
 626
 627         strbuf_release(&msg);
 628         return ret;
 629 }
 630
 631 static int rebase_config(const char *var, const char *value, void *data)
 632 {
 633         struct rebase_options *opts = data;
 634
 635         if (!strcmp(var, "rebase.stat")) {
 636                 if (git_config_bool(var, value))
 637                         opts->flags |= REBASE_DIFFSTAT;
 638                 else
 639                         opts->flags &= !REBASE_DIFFSTAT;
 640                 return 0;
 641         }
 642
 643         if (!strcmp(var, "rebase.autosquash")) {
 644                 opts->autosquash = git_config_bool(var, value);
 645                 return 0;
 646         }
 647
 648         if (!strcmp(var, "commit.gpgsign")) {
 649                 free(opts->gpg_sign_opt);
 650                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 651                         xstrdup("-S") : NULL;
 652                 return 0;
 653         }
 654
 655         if (!strcmp(var, "rebase.autostash")) {
 656                 opts->autostash = git_config_bool(var, value);
 657                 return 0;
 658         }
 659
 660         return git_default_config(var, value, data);
 661 }
 662
 663 /*
 664  * Determines whether the commits in from..to are linear, i.e. contain
 665  * no merge commits. This function *expects* `from` to be an ancestor of
 666  * `to`.
 667  */
 668 static int is_linear_history(struct commit *from, struct commit *to)
 669 {
 670         while (to && to != from) {
 671                 parse_commit(to);
 672                 if (!to->parents)
 673                         return 1;
 674                 if (to->parents->next)
 675                         return 0;
 676                 to = to->parents->item;
 677         }
 678         return 1;
 679 }
 680
 681 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 682                             struct object_id *merge_base)
 683 {
 684         struct commit *head = lookup_commit(the_repository, head_oid);
 685         struct commit_list *merge_bases;
 686         int res;
 687
 688         if (!head)
 689                 return 0;
 690
 691         merge_bases = get_merge_bases(onto, head);
 692         if (merge_bases && !merge_bases->next) {
 693                 oidcpy(merge_base, &merge_bases->item->object.oid);
 694                 res = oideq(merge_base, &onto->object.oid);
 695         } else {
 696                 oidcpy(merge_base, &null_oid);
 697                 res = 0;
 698         }
 699         free_commit_list(merge_bases);
 700         return res && is_linear_history(onto, head);
 701 }
 702
 703 /* -i followed by -m is still -i */
 704 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 705 {
 706         struct rebase_options *opts = opt->value;
 707
 708         if (!is_interactive(opts))
 709                 opts->type = REBASE_MERGE;
 710
 711         return 0;
 712 }
 713
 714 /* -i followed by -p is still explicitly interactive, but -p alone is not */
 715 static int parse_opt_interactive(const struct option *opt, const char *arg,
 716                                  int unset)
 717 {
 718         struct rebase_options *opts = opt->value;
 719
 720         opts->type = REBASE_INTERACTIVE;
 721         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 722
 723         return 0;
 724 }
 725
 726 static void NORETURN error_on_missing_default_upstream(void)
 727 {
 728         struct branch *current_branch = branch_get(NULL);
 729
 730         printf(_("%s\n"
 731                  "Please specify which branch you want to rebase against.\n"
 732                  "See git-rebase(1) for details.\n"
 733                  "\n"
 734                  "    git rebase '<branch>'\n"
 735                  "\n"),
 736                 current_branch ? _("There is no tracking information for "
 737                         "the current branch.") :
 738                         _("You are not currently on a branch."));
 739
 740         if (current_branch) {
 741                 const char *remote = current_branch->remote_name;
 742
 743                 if (!remote)
 744                         remote = _("<remote>");
 745
 746                 printf(_("If you wish to set tracking information for this "
 747                          "branch you can do so with:\n"
 748                          "\n"
 749                          "    git branch --set-upstream-to=%s/<branch> %s\n"
 750                          "\n"),
 751                        remote, current_branch->name);
 752         }
 753         exit(1);
 754 }
 755
 756 int cmd_rebase(int argc, const char **argv, const char *prefix)
 757 {
 758         struct rebase_options options = {
 759                 .type = REBASE_UNSPECIFIED,
 760                 .flags = REBASE_NO_QUIET,
 761                 .git_am_opts = ARGV_ARRAY_INIT,
 762                 .allow_rerere_autoupdate  = -1,
 763                 .allow_empty_message = 1,
 764                 .git_format_patch_opt = STRBUF_INIT,
 765         };
 766         const char *branch_name;
 767         int ret, flags, total_argc, in_progress = 0;
 768         int ok_to_skip_pre_rebase = 0;
 769         struct strbuf msg = STRBUF_INIT;
 770         struct strbuf revisions = STRBUF_INIT;
 771         struct strbuf buf = STRBUF_INIT;
 772         struct object_id merge_base;
 773         enum {
 774                 NO_ACTION,
 775                 ACTION_CONTINUE,
 776                 ACTION_SKIP,
 777                 ACTION_ABORT,
 778                 ACTION_QUIT,
 779                 ACTION_EDIT_TODO,
 780                 ACTION_SHOW_CURRENT_PATCH,
 781         } action = NO_ACTION;
 782         const char *gpg_sign = NULL;
 783         struct string_list exec = STRING_LIST_INIT_NODUP;
 784         const char *rebase_merges = NULL;
 785         int fork_point = -1;
 786         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 787         struct object_id squash_onto;
 788         char *squash_onto_name = NULL;
 789         struct option builtin_rebase_options[] = {
 790                 OPT_STRING(0, "onto", &options.onto_name,
 791                            N_("revision"),
 792                            N_("rebase onto given branch instead of upstream")),
 793                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 794                          N_("allow pre-rebase hook to run")),
 795                 OPT_NEGBIT('q', "quiet", &options.flags,
 796                            N_("be quiet. implies --no-stat"),
 797                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 798                 OPT_BIT('v', "verbose", &options.flags,
 799                         N_("display a diffstat of what changed upstream"),
 800                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 801                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 802                         N_("do not show diffstat of what changed upstream"),
 803                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 804                 OPT_BOOL(0, "signoff", &options.signoff,
 805                          N_("add a Signed-off-by: line to each commit")),
 806                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
 807                                   NULL, N_("passed to 'git am'"),
 808                                   PARSE_OPT_NOARG),
 809                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 810                                   &options.git_am_opts, NULL,
 811                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
 812                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
 813                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
 814                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 815                                   N_("passed to 'git apply'"), 0),
 816                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
 817                                   N_("action"), N_("passed to 'git apply'"), 0),
 818                 OPT_BIT('f', "force-rebase", &options.flags,
 819                         N_("cherry-pick all commits, even if unchanged"),
 820                         REBASE_FORCE),
 821                 OPT_BIT(0, "no-ff", &options.flags,
 822                         N_("cherry-pick all commits, even if unchanged"),
 823                         REBASE_FORCE),
 824                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
 825                             ACTION_CONTINUE),
 826                 OPT_CMDMODE(0, "skip", &action,
 827                             N_("skip current patch and continue"), ACTION_SKIP),
 828                 OPT_CMDMODE(0, "abort", &action,
 829                             N_("abort and check out the original branch"),
 830                             ACTION_ABORT),
 831                 OPT_CMDMODE(0, "quit", &action,
 832                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
 833                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 834                             "during an interactive rebase"), ACTION_EDIT_TODO),
 835                 OPT_CMDMODE(0, "show-current-patch", &action,
 836                             N_("show the patch file being applied or merged"),
 837                             ACTION_SHOW_CURRENT_PATCH),
 838                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 839                         N_("use merging strategies to rebase"),
 840                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 841                         parse_opt_merge },
 842                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 843                         N_("let the user edit the list of commits to rebase"),
 844                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 845                         parse_opt_interactive },
 846                 OPT_SET_INT('p', "preserve-merges", &options.type,
 847                             N_("try to recreate merges instead of ignoring "
 848                                "them"), REBASE_PRESERVE_MERGES),
 849                 OPT_BOOL(0, "rerere-autoupdate",
 850                          &options.allow_rerere_autoupdate,
 851                          N_("allow rerere to update index  with resolved "
 852                             "conflict")),
 853                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
 854                          N_("preserve empty commits during rebase")),
 855                 OPT_BOOL(0, "autosquash", &options.autosquash,
 856                          N_("move commits that begin with "
 857                             "squash!/fixup! under -i")),
 858                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 859                         N_("GPG-sign commits"),
 860                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 861                 OPT_BOOL(0, "autostash", &options.autostash,
 862                          N_("automatically stash/stash pop before and after")),
 863                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 864                                 N_("add exec lines after each commit of the "
 865                                    "editable list")),
 866                 OPT_BOOL(0, "allow-empty-message",
 867                          &options.allow_empty_message,
 868                          N_("allow rebasing commits with empty messages")),
 869                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 870                         N_("mode"),
 871                         N_("try to rebase merges instead of skipping them"),
 872                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 873                 OPT_BOOL(0, "fork-point", &fork_point,
 874                          N_("use 'merge-base --fork-point' to refine upstream")),
 875                 OPT_STRING('s', "strategy", &options.strategy,
 876                            N_("strategy"), N_("use the given merge strategy")),
 877                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 878                                 N_("option"),
 879                                 N_("pass the argument through to the merge "
 880                                    "strategy")),
 881                 OPT_BOOL(0, "root", &options.root,
 882                          N_("rebase all reachable commits up to the root(s)")),
 883                 OPT_END(),
 884         };
 885         int i;
 886
 887         /*
 888          * NEEDSWORK: Once the builtin rebase has been tested enough
 889          * and git-legacy-rebase.sh is retired to contrib/, this preamble
 890          * can be removed.
 891          */
 892
 893         if (!use_builtin_rebase()) {
 894                 const char *path = mkpath("%s/git-legacy-rebase",
 895                                           git_exec_path());
 896
 897                 if (sane_execvp(path, (char **)argv) < 0)
 898                         die_errno(_("could not exec %s"), path);
 899                 else
 900                         BUG("sane_execvp() returned???");
 901         }
 902
 903         if (argc == 2 && !strcmp(argv[1], "-h"))
 904                 usage_with_options(builtin_rebase_usage,
 905                                    builtin_rebase_options);
 906
 907         prefix = setup_git_directory();
 908         trace_repo_setup(prefix);
 909         setup_work_tree();
 910
 911         git_config(rebase_config, &options);
 912
 913         strbuf_reset(&buf);
 914         strbuf_addf(&buf, "%s/applying", apply_dir());
 915         if(file_exists(buf.buf))
 916                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
 917
 918         if (is_directory(apply_dir())) {
 919                 options.type = REBASE_AM;
 920                 options.state_dir = apply_dir();
 921         } else if (is_directory(merge_dir())) {
 922                 strbuf_reset(&buf);
 923                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
 924                 if (is_directory(buf.buf)) {
 925                         options.type = REBASE_PRESERVE_MERGES;
 926                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 927                 } else {
 928                         strbuf_reset(&buf);
 929                         strbuf_addf(&buf, "%s/interactive", merge_dir());
 930                         if(file_exists(buf.buf)) {
 931                                 options.type = REBASE_INTERACTIVE;
 932                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 933                         } else
 934                                 options.type = REBASE_MERGE;
 935                 }
 936                 options.state_dir = merge_dir();
 937         }
 938
 939         if (options.type != REBASE_UNSPECIFIED)
 940                 in_progress = 1;
 941
 942         total_argc = argc;
 943         argc = parse_options(argc, argv, prefix,
 944                              builtin_rebase_options,
 945                              builtin_rebase_usage, 0);
 946
 947         if (action != NO_ACTION && total_argc != 2) {
 948                 usage_with_options(builtin_rebase_usage,
 949                                    builtin_rebase_options);
 950         }
 951
 952         if (argc > 2)
 953                 usage_with_options(builtin_rebase_usage,
 954                                    builtin_rebase_options);
 955
 956         if (action != NO_ACTION && !in_progress)
 957                 die(_("No rebase in progress?"));
 958
 959         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 960                 die(_("The --edit-todo action can only be used during "
 961                       "interactive rebase."));
 962
 963         switch (action) {
 964         case ACTION_CONTINUE: {
 965                 struct object_id head;
 966                 struct lock_file lock_file = LOCK_INIT;
 967                 int fd;
 968
 969                 options.action = "continue";
 970
 971                 /* Sanity check */
 972                 if (get_oid("HEAD", &head))
 973                         die(_("Cannot read HEAD"));
 974
 975                 fd = hold_locked_index(&lock_file, 0);
 976                 if (read_index(the_repository->index) < 0)
 977                         die(_("could not read index"));
 978                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
 979                               NULL);
 980                 if (0 <= fd)
 981                         update_index_if_able(the_repository->index,
 982                                              &lock_file);
 983                 rollback_lock_file(&lock_file);
 984
 985                 if (has_unstaged_changes(1)) {
 986                         puts(_("You must edit all merge conflicts and then\n"
 987                                "mark them as resolved using git add"));
 988                         exit(1);
 989                 }
 990                 if (read_basic_state(&options))
 991                         exit(1);
 992                 goto run_rebase;
 993         }
 994         case ACTION_SKIP: {
 995                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 996
 997                 options.action = "skip";
 998
 999                 rerere_clear(&merge_rr);
1000                 string_list_clear(&merge_rr, 1);
1001
1002                 if (reset_head(NULL, "reset", NULL, 0, NULL, NULL) < 0)
1003                         die(_("could not discard worktree changes"));
1004                 if (read_basic_state(&options))
1005                         exit(1);
1006                 goto run_rebase;
1007         }
1008         case ACTION_ABORT: {
1009                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1010                 options.action = "abort";
1011
1012                 rerere_clear(&merge_rr);
1013                 string_list_clear(&merge_rr, 1);
1014
1015                 if (read_basic_state(&options))
1016                         exit(1);
1017                 if (reset_head(&options.orig_head, "reset",
1018                                options.head_name, 0, NULL, NULL) < 0)
1019                         die(_("could not move back to %s"),
1020                             oid_to_hex(&options.orig_head));
1021                 ret = finish_rebase(&options);
1022                 goto cleanup;
1023         }
1024         case ACTION_QUIT: {
1025                 strbuf_reset(&buf);
1026                 strbuf_addstr(&buf, options.state_dir);
1027                 ret = !!remove_dir_recursively(&buf, 0);
1028                 if (ret)
1029                         die(_("could not remove '%s'"), options.state_dir);
1030                 goto cleanup;
1031         }
1032         case ACTION_EDIT_TODO:
1033                 options.action = "edit-todo";
1034                 options.dont_finish_rebase = 1;
1035                 goto run_rebase;
1036         case ACTION_SHOW_CURRENT_PATCH:
1037                 options.action = "show-current-patch";
1038                 options.dont_finish_rebase = 1;
1039                 goto run_rebase;
1040         case NO_ACTION:
1041                 break;
1042         default:
1043                 BUG("action: %d", action);
1044         }
1045
1046         /* Make sure no rebase is in progress */
1047         if (in_progress) {
1048                 const char *last_slash = strrchr(options.state_dir, '/');
1049                 const char *state_dir_base =
1050                         last_slash ? last_slash + 1 : options.state_dir;
1051                 const char *cmd_live_rebase =
1052                         "git rebase (--continue | --abort | --skip)";
1053                 strbuf_reset(&buf);
1054                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1055                 die(_("It seems that there is already a %s directory, and\n"
1056                       "I wonder if you are in the middle of another rebase.  "
1057                       "If that is the\n"
1058                       "case, please try\n\t%s\n"
1059                       "If that is not the case, please\n\t%s\n"
1060                       "and run me again.  I am stopping in case you still "
1061                       "have something\n"
1062                       "valuable there.\n"),
1063                     state_dir_base, cmd_live_rebase, buf.buf);
1064         }
1065
1066         for (i = 0; i < options.git_am_opts.argc; i++) {
1067                 const char *option = options.git_am_opts.argv[i];
1068                 if (!strcmp(option, "--committer-date-is-author-date") ||
1069                     !strcmp(option, "--ignore-date") ||
1070                     !strcmp(option, "--whitespace=fix") ||
1071                     !strcmp(option, "--whitespace=strip"))
1072                         options.flags |= REBASE_FORCE;
1073         }
1074
1075         if (!(options.flags & REBASE_NO_QUIET))
1076                 argv_array_push(&options.git_am_opts, "-q");
1077
1078         if (options.keep_empty)
1079                 imply_interactive(&options, "--keep-empty");
1080
1081         if (gpg_sign) {
1082                 free(options.gpg_sign_opt);
1083                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1084         }
1085
1086         if (exec.nr) {
1087                 int i;
1088
1089                 imply_interactive(&options, "--exec");
1090
1091                 strbuf_reset(&buf);
1092                 for (i = 0; i < exec.nr; i++)
1093                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1094                 options.cmd = xstrdup(buf.buf);
1095         }
1096
1097         if (rebase_merges) {
1098                 if (!*rebase_merges)
1099                         ; /* default mode; do nothing */
1100                 else if (!strcmp("rebase-cousins", rebase_merges))
1101                         options.rebase_cousins = 1;
1102                 else if (strcmp("no-rebase-cousins", rebase_merges))
1103                         die(_("Unknown mode: %s"), rebase_merges);
1104                 options.rebase_merges = 1;
1105                 imply_interactive(&options, "--rebase-merges");
1106         }
1107
1108         if (strategy_options.nr) {
1109                 int i;
1110
1111                 if (!options.strategy)
1112                         options.strategy = "recursive";
1113
1114                 strbuf_reset(&buf);
1115                 for (i = 0; i < strategy_options.nr; i++)
1116                         strbuf_addf(&buf, " --%s",
1117                                     strategy_options.items[i].string);
1118                 options.strategy_opts = xstrdup(buf.buf);
1119         }
1120
1121         if (options.strategy) {
1122                 options.strategy = xstrdup(options.strategy);
1123                 switch (options.type) {
1124                 case REBASE_AM:
1125                         die(_("--strategy requires --merge or --interactive"));
1126                 case REBASE_MERGE:
1127                 case REBASE_INTERACTIVE:
1128                 case REBASE_PRESERVE_MERGES:
1129                         /* compatible */
1130                         break;
1131                 case REBASE_UNSPECIFIED:
1132                         options.type = REBASE_MERGE;
1133                         break;
1134                 default:
1135                         BUG("unhandled rebase type (%d)", options.type);
1136                 }
1137         }
1138
1139         if (options.root && !options.onto_name)
1140                 imply_interactive(&options, "--root without --onto");
1141
1142         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1143                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1144
1145         switch (options.type) {
1146         case REBASE_MERGE:
1147         case REBASE_INTERACTIVE:
1148         case REBASE_PRESERVE_MERGES:
1149                 options.state_dir = merge_dir();
1150                 break;
1151         case REBASE_AM:
1152                 options.state_dir = apply_dir();
1153                 break;
1154         default:
1155                 /* the default rebase backend is `--am` */
1156                 options.type = REBASE_AM;
1157                 options.state_dir = apply_dir();
1158                 break;
1159         }
1160
1161         if (options.git_am_opts.argc) {
1162                 /* all am options except -q are compatible only with --am */
1163                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1164                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1165                                 break;
1166
1167                 if (is_interactive(&options) && i >= 0)
1168                         die(_("error: cannot combine interactive options "
1169                               "(--interactive, --exec, --rebase-merges, "
1170                               "--preserve-merges, --keep-empty, --root + "
1171                               "--onto) with am options (%s)"), buf.buf);
1172                 if (options.type == REBASE_MERGE && i >= 0)
1173                         die(_("error: cannot combine merge options (--merge, "
1174                               "--strategy, --strategy-option) with am options "
1175                               "(%s)"), buf.buf);
1176         }
1177
1178         if (options.signoff) {
1179                 if (options.type == REBASE_PRESERVE_MERGES)
1180                         die("cannot combine '--signoff' with "
1181                             "'--preserve-merges'");
1182                 argv_array_push(&options.git_am_opts, "--signoff");
1183                 options.flags |= REBASE_FORCE;
1184         }
1185
1186         if (options.type == REBASE_PRESERVE_MERGES)
1187                 /*
1188                  * Note: incompatibility with --signoff handled in signoff block above
1189                  * Note: incompatibility with --interactive is just a strong warning;
1190                  *       git-rebase.txt caveats with "unless you know what you are doing"
1191                  */
1192                 if (options.rebase_merges)
1193                         die(_("error: cannot combine '--preserve-merges' with "
1194                               "'--rebase-merges'"));
1195
1196         if (options.rebase_merges) {
1197                 if (strategy_options.nr)
1198                         die(_("error: cannot combine '--rebase-merges' with "
1199                               "'--strategy-option'"));
1200                 if (options.strategy)
1201                         die(_("error: cannot combine '--rebase-merges' with "
1202                               "'--strategy'"));
1203         }
1204
1205         if (!options.root) {
1206                 if (argc < 1) {
1207                         struct branch *branch;
1208
1209                         branch = branch_get(NULL);
1210                         options.upstream_name = branch_get_upstream(branch,
1211                                                                     NULL);
1212                         if (!options.upstream_name)
1213                                 error_on_missing_default_upstream();
1214                         if (fork_point < 0)
1215                                 fork_point = 1;
1216                 } else {
1217                         options.upstream_name = argv[0];
1218                         argc--;
1219                         argv++;
1220                         if (!strcmp(options.upstream_name, "-"))
1221                                 options.upstream_name = "@{-1}";
1222                 }
1223                 options.upstream = peel_committish(options.upstream_name);
1224                 if (!options.upstream)
1225                         die(_("invalid upstream '%s'"), options.upstream_name);
1226                 options.upstream_arg = options.upstream_name;
1227         } else {
1228                 if (!options.onto_name) {
1229                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1230                                         &squash_onto, NULL, NULL) < 0)
1231                                 die(_("Could not create new root commit"));
1232                         options.squash_onto = &squash_onto;
1233                         options.onto_name = squash_onto_name =
1234                                 xstrdup(oid_to_hex(&squash_onto));
1235                 }
1236                 options.upstream_name = NULL;
1237                 options.upstream = NULL;
1238                 if (argc > 1)
1239                         usage_with_options(builtin_rebase_usage,
1240                                            builtin_rebase_options);
1241                 options.upstream_arg = "--root";
1242         }
1243
1244         /* Make sure the branch to rebase onto is valid. */
1245         if (!options.onto_name)
1246                 options.onto_name = options.upstream_name;
1247         if (strstr(options.onto_name, "...")) {
1248                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
1249                         die(_("'%s': need exactly one merge base"),
1250                             options.onto_name);
1251                 options.onto = lookup_commit_or_die(&merge_base,
1252                                                     options.onto_name);
1253         } else {
1254                 options.onto = peel_committish(options.onto_name);
1255                 if (!options.onto)
1256                         die(_("Does not point to a valid commit '%s'"),
1257                                 options.onto_name);
1258         }
1259
1260         /*
1261          * If the branch to rebase is given, that is the branch we will rebase
1262          * branch_name -- branch/commit being rebased, or
1263          *                HEAD (already detached)
1264          * orig_head -- commit object name of tip of the branch before rebasing
1265          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1266          */
1267         if (argc == 1) {
1268                 /* Is it "rebase other branchname" or "rebase other commit"? */
1269                 branch_name = argv[0];
1270                 options.switch_to = argv[0];
1271
1272                 /* Is it a local branch? */
1273                 strbuf_reset(&buf);
1274                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1275                 if (!read_ref(buf.buf, &options.orig_head))
1276                         options.head_name = xstrdup(buf.buf);
1277                 /* If not is it a valid ref (branch or commit)? */
1278                 else if (!get_oid(branch_name, &options.orig_head))
1279                         options.head_name = NULL;
1280                 else
1281                         die(_("fatal: no such branch/commit '%s'"),
1282                             branch_name);
1283         } else if (argc == 0) {
1284                 /* Do not need to switch branches, we are already on it. */
1285                 options.head_name =
1286                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1287                                          &flags));
1288                 if (!options.head_name)
1289                         die(_("No such ref: %s"), "HEAD");
1290                 if (flags & REF_ISSYMREF) {
1291                         if (!skip_prefix(options.head_name,
1292                                          "refs/heads/", &branch_name))
1293                                 branch_name = options.head_name;
1294
1295                 } else {
1296                         free(options.head_name);
1297                         options.head_name = NULL;
1298                         branch_name = "HEAD";
1299                 }
1300                 if (get_oid("HEAD", &options.orig_head))
1301                         die(_("Could not resolve HEAD to a revision"));
1302         } else
1303                 BUG("unexpected number of arguments left to parse");
1304
1305         if (fork_point > 0) {
1306                 struct commit *head =
1307                         lookup_commit_reference(the_repository,
1308                                                 &options.orig_head);
1309                 options.restrict_revision =
1310                         get_fork_point(options.upstream_name, head);
1311         }
1312
1313         if (read_index(the_repository->index) < 0)
1314                 die(_("could not read index"));
1315
1316         if (options.autostash) {
1317                 struct lock_file lock_file = LOCK_INIT;
1318                 int fd;
1319
1320                 fd = hold_locked_index(&lock_file, 0);
1321                 refresh_cache(REFRESH_QUIET);
1322                 if (0 <= fd)
1323                         update_index_if_able(&the_index, &lock_file);
1324                 rollback_lock_file(&lock_file);
1325
1326                 if (has_unstaged_changes(1) || has_uncommitted_changes(1)) {
1327                         const char *autostash =
1328                                 state_dir_path("autostash", &options);
1329                         struct child_process stash = CHILD_PROCESS_INIT;
1330                         struct object_id oid;
1331                         struct commit *head =
1332                                 lookup_commit_reference(the_repository,
1333                                                         &options.orig_head);
1334
1335                         argv_array_pushl(&stash.args,
1336                                          "stash", "create", "autostash", NULL);
1337                         stash.git_cmd = 1;
1338                         stash.no_stdin = 1;
1339                         strbuf_reset(&buf);
1340                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1341                                 die(_("Cannot autostash"));
1342                         strbuf_trim_trailing_newline(&buf);
1343                         if (get_oid(buf.buf, &oid))
1344                                 die(_("Unexpected stash response: '%s'"),
1345                                     buf.buf);
1346                         strbuf_reset(&buf);
1347                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1348
1349                         if (safe_create_leading_directories_const(autostash))
1350                                 die(_("Could not create directory for '%s'"),
1351                                     options.state_dir);
1352                         write_file(autostash, "%s", oid_to_hex(&oid));
1353                         printf(_("Created autostash: %s\n"), buf.buf);
1354                         if (reset_head(&head->object.oid, "reset --hard",
1355                                        NULL, 0, NULL, NULL) < 0)
1356                                 die(_("could not reset --hard"));
1357                         printf(_("HEAD is now at %s"),
1358                                find_unique_abbrev(&head->object.oid,
1359                                                   DEFAULT_ABBREV));
1360                         strbuf_reset(&buf);
1361                         pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1362                         if (buf.len > 0)
1363                                 printf(" %s", buf.buf);
1364                         putchar('\n');
1365
1366                         if (discard_index(the_repository->index) < 0 ||
1367                                 read_index(the_repository->index) < 0)
1368                                 die(_("could not read index"));
1369                 }
1370         }
1371
1372         if (require_clean_work_tree("rebase",
1373                                     _("Please commit or stash them."), 1, 1)) {
1374                 ret = 1;
1375                 goto cleanup;
1376         }
1377
1378         /*
1379          * Now we are rebasing commits upstream..orig_head (or with --root,
1380          * everything leading up to orig_head) on top of onto.
1381          */
1382
1383         /*
1384          * Check if we are already based on onto with linear history,
1385          * but this should be done only when upstream and onto are the same
1386          * and if this is not an interactive rebase.
1387          */
1388         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1389             !is_interactive(&options) && !options.restrict_revision &&
1390             options.upstream &&
1391             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1392                 int flag;
1393
1394                 if (!(options.flags & REBASE_FORCE)) {
1395                         /* Lazily switch to the target branch if needed... */
1396                         if (options.switch_to) {
1397                                 struct object_id oid;
1398
1399                                 if (get_oid(options.switch_to, &oid) < 0) {
1400                                         ret = !!error(_("could not parse '%s'"),
1401                                                       options.switch_to);
1402                                         goto cleanup;
1403                                 }
1404
1405                                 strbuf_reset(&buf);
1406                                 strbuf_addf(&buf, "rebase: checkout %s",
1407                                             options.switch_to);
1408                                 if (reset_head(&oid, "checkout",
1409                                                options.head_name, 0,
1410                                                NULL, NULL) < 0) {
1411                                         ret = !!error(_("could not switch to "
1412                                                         "%s"),
1413                                                       options.switch_to);
1414                                         goto cleanup;
1415                                 }
1416                         }
1417
1418                         if (!(options.flags & REBASE_NO_QUIET))
1419                                 ; /* be quiet */
1420                         else if (!strcmp(branch_name, "HEAD") &&
1421                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1422                                 puts(_("HEAD is up to date."));
1423                         else
1424                                 printf(_("Current branch %s is up to date.\n"),
1425                                        branch_name);
1426                         ret = !!finish_rebase(&options);
1427                         goto cleanup;
1428                 } else if (!(options.flags & REBASE_NO_QUIET))
1429                         ; /* be quiet */
1430                 else if (!strcmp(branch_name, "HEAD") &&
1431                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1432                         puts(_("HEAD is up to date, rebase forced."));
1433                 else
1434                         printf(_("Current branch %s is up to date, rebase "
1435                                  "forced.\n"), branch_name);
1436         }
1437
1438         /* If a hook exists, give it a chance to interrupt*/
1439         if (!ok_to_skip_pre_rebase &&
1440             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1441                         argc ? argv[0] : NULL, NULL))
1442                 die(_("The pre-rebase hook refused to rebase."));
1443
1444         if (options.flags & REBASE_DIFFSTAT) {
1445                 struct diff_options opts;
1446
1447                 if (options.flags & REBASE_VERBOSE)
1448                         printf(_("Changes from %s to %s:\n"),
1449                                 oid_to_hex(&merge_base),
1450                                 oid_to_hex(&options.onto->object.oid));
1451
1452                 /* We want color (if set), but no pager */
1453                 diff_setup(&opts);
1454                 opts.stat_width = -1; /* use full terminal width */
1455                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1456                 opts.output_format |=
1457                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1458                 opts.detect_rename = DIFF_DETECT_RENAME;
1459                 diff_setup_done(&opts);
1460                 diff_tree_oid(&merge_base, &options.onto->object.oid,
1461                               "", &opts);
1462                 diffcore_std(&opts);
1463                 diff_flush(&opts);
1464         }
1465
1466         if (is_interactive(&options))
1467                 goto run_rebase;
1468
1469         /* Detach HEAD and reset the tree */
1470         if (options.flags & REBASE_NO_QUIET)
1471                 printf(_("First, rewinding head to replay your work on top of "
1472                          "it...\n"));
1473
1474         strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
1475         if (reset_head(&options.onto->object.oid, "checkout", NULL, 1,
1476             NULL, msg.buf))
1477                 die(_("Could not detach HEAD"));
1478         strbuf_release(&msg);
1479
1480         /*
1481          * If the onto is a proper descendant of the tip of the branch, then
1482          * we just fast-forwarded.
1483          */
1484         strbuf_reset(&msg);
1485         if (!oidcmp(&merge_base, &options.orig_head)) {
1486                 printf(_("Fast-forwarded %s to %s. \n"),
1487                         branch_name, options.onto_name);
1488                 strbuf_addf(&msg, "rebase finished: %s onto %s",
1489                         options.head_name ? options.head_name : "detached HEAD",
1490                         oid_to_hex(&options.onto->object.oid));
1491                 reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1492                            "HEAD", msg.buf);
1493                 strbuf_release(&msg);
1494                 ret = !!finish_rebase(&options);
1495                 goto cleanup;
1496         }
1497
1498         strbuf_addf(&revisions, "%s..%s",
1499                     options.root ? oid_to_hex(&options.onto->object.oid) :
1500                     (options.restrict_revision ?
1501                      oid_to_hex(&options.restrict_revision->object.oid) :
1502                      oid_to_hex(&options.upstream->object.oid)),
1503                     oid_to_hex(&options.orig_head));
1504
1505         options.revisions = revisions.buf;
1506
1507 run_rebase:
1508         ret = !!run_specific_rebase(&options);
1509
1510 cleanup:
1511         strbuf_release(&revisions);
1512         free(options.head_name);
1513         free(options.gpg_sign_opt);
1514         free(options.cmd);
1515         free(squash_onto_name);
1516         return ret;
1517 }