git.oblomov.eu Git - git/blob - builtin/rebase.c

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #include "builtin.h"
   8 #include "run-command.h"
   9 #include "exec-cmd.h"
  10 #include "argv-array.h"
  11 #include "dir.h"
  12 #include "packfile.h"
  13 #include "refs.h"
  14 #include "quote.h"
  15 #include "config.h"
  16 #include "cache-tree.h"
  17 #include "unpack-trees.h"
  18 #include "lockfile.h"
  19 #include "parse-options.h"
  20 #include "commit.h"
  21 #include "diff.h"
  22 #include "wt-status.h"
  23 #include "revision.h"
  24 #include "rerere.h"
  25
  26 static char const * const builtin_rebase_usage[] = {
  27         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  28                 "[<upstream>] [<branch>]"),
  29         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  30                 "--root [<branch>]"),
  31         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  32         NULL
  33 };
  34
  35 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  36 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  37
  38 enum rebase_type {
  39         REBASE_UNSPECIFIED = -1,
  40         REBASE_AM,
  41         REBASE_MERGE,
  42         REBASE_INTERACTIVE,
  43         REBASE_PRESERVE_MERGES
  44 };
  45
  46 static int use_builtin_rebase(void)
  47 {
  48         struct child_process cp = CHILD_PROCESS_INIT;
  49         struct strbuf out = STRBUF_INIT;
  50         int ret;
  51
  52         argv_array_pushl(&cp.args,
  53                          "config", "--bool", "rebase.usebuiltin", NULL);
  54         cp.git_cmd = 1;
  55         if (capture_command(&cp, &out, 6)) {
  56                 strbuf_release(&out);
  57                 return 1;
  58         }
  59
  60         strbuf_trim(&out);
  61         ret = !strcmp("true", out.buf);
  62         strbuf_release(&out);
  63         return ret;
  64 }
  65
  66 struct rebase_options {
  67         enum rebase_type type;
  68         const char *state_dir;
  69         struct commit *upstream;
  70         const char *upstream_name;
  71         const char *upstream_arg;
  72         char *head_name;
  73         struct object_id orig_head;
  74         struct commit *onto;
  75         const char *onto_name;
  76         const char *revisions;
  77         const char *switch_to;
  78         int root;
  79         struct object_id *squash_onto;
  80         struct commit *restrict_revision;
  81         int dont_finish_rebase;
  82         enum {
  83                 REBASE_NO_QUIET = 1<<0,
  84                 REBASE_VERBOSE = 1<<1,
  85                 REBASE_DIFFSTAT = 1<<2,
  86                 REBASE_FORCE = 1<<3,
  87                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  88         } flags;
  89         struct strbuf git_am_opt;
  90         const char *action;
  91         int signoff;
  92         int allow_rerere_autoupdate;
  93         int keep_empty;
  94         int autosquash;
  95         char *gpg_sign_opt;
  96         int autostash;
  97         char *cmd;
  98         int allow_empty_message;
  99         int rebase_merges, rebase_cousins;
 100         char *strategy, *strategy_opts;
 101         struct strbuf git_format_patch_opt;
 102 };
 103
 104 static int is_interactive(struct rebase_options *opts)
 105 {
 106         return opts->type == REBASE_INTERACTIVE ||
 107                 opts->type == REBASE_PRESERVE_MERGES;
 108 }
 109
 110 static void imply_interactive(struct rebase_options *opts, const char *option)
 111 {
 112         switch (opts->type) {
 113         case REBASE_AM:
 114                 die(_("%s requires an interactive rebase"), option);
 115                 break;
 116         case REBASE_INTERACTIVE:
 117         case REBASE_PRESERVE_MERGES:
 118                 break;
 119         case REBASE_MERGE:
 120                 /* we silently *upgrade* --merge to --interactive if needed */
 121         default:
 122                 opts->type = REBASE_INTERACTIVE; /* implied */
 123                 break;
 124         }
 125 }
 126
 127 /* Returns the filename prefixed by the state_dir */
 128 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 129 {
 130         static struct strbuf path = STRBUF_INIT;
 131         static size_t prefix_len;
 132
 133         if (!prefix_len) {
 134                 strbuf_addf(&path, "%s/", opts->state_dir);
 135                 prefix_len = path.len;
 136         }
 137
 138         strbuf_setlen(&path, prefix_len);
 139         strbuf_addstr(&path, filename);
 140         return path.buf;
 141 }
 142
 143 /* Read one file, then strip line endings */
 144 static int read_one(const char *path, struct strbuf *buf)
 145 {
 146         if (strbuf_read_file(buf, path, 0) < 0)
 147                 return error_errno(_("could not read '%s'"), path);
 148         strbuf_trim_trailing_newline(buf);
 149         return 0;
 150 }
 151
 152 /* Initialize the rebase options from the state directory. */
 153 static int read_basic_state(struct rebase_options *opts)
 154 {
 155         struct strbuf head_name = STRBUF_INIT;
 156         struct strbuf buf = STRBUF_INIT;
 157         struct object_id oid;
 158
 159         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 160             read_one(state_dir_path("onto", opts), &buf))
 161                 return -1;
 162         opts->head_name = starts_with(head_name.buf, "refs/") ?
 163                 xstrdup(head_name.buf) : NULL;
 164         strbuf_release(&head_name);
 165         if (get_oid(buf.buf, &oid))
 166                 return error(_("could not get 'onto': '%s'"), buf.buf);
 167         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 168
 169         /*
 170          * We always write to orig-head, but interactive rebase used to write to
 171          * head. Fall back to reading from head to cover for the case that the
 172          * user upgraded git with an ongoing interactive rebase.
 173          */
 174         strbuf_reset(&buf);
 175         if (file_exists(state_dir_path("orig-head", opts))) {
 176                 if (read_one(state_dir_path("orig-head", opts), &buf))
 177                         return -1;
 178         } else if (read_one(state_dir_path("head", opts), &buf))
 179                 return -1;
 180         if (get_oid(buf.buf, &opts->orig_head))
 181                 return error(_("invalid orig-head: '%s'"), buf.buf);
 182
 183         strbuf_reset(&buf);
 184         if (read_one(state_dir_path("quiet", opts), &buf))
 185                 return -1;
 186         if (buf.len)
 187                 opts->flags &= ~REBASE_NO_QUIET;
 188         else
 189                 opts->flags |= REBASE_NO_QUIET;
 190
 191         if (file_exists(state_dir_path("verbose", opts)))
 192                 opts->flags |= REBASE_VERBOSE;
 193
 194         if (file_exists(state_dir_path("signoff", opts))) {
 195                 opts->signoff = 1;
 196                 opts->flags |= REBASE_FORCE;
 197         }
 198
 199         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 200                 strbuf_reset(&buf);
 201                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 202                             &buf))
 203                         return -1;
 204                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 205                         opts->allow_rerere_autoupdate = 1;
 206                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 207                         opts->allow_rerere_autoupdate = 0;
 208                 else
 209                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 210                                   "'%s'"), buf.buf);
 211         } else
 212                 opts->allow_rerere_autoupdate = -1;
 213
 214         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 215                 strbuf_reset(&buf);
 216                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 217                             &buf))
 218                         return -1;
 219                 free(opts->gpg_sign_opt);
 220                 opts->gpg_sign_opt = xstrdup(buf.buf);
 221         }
 222
 223         if (file_exists(state_dir_path("strategy", opts))) {
 224                 strbuf_reset(&buf);
 225                 if (read_one(state_dir_path("strategy", opts), &buf))
 226                         return -1;
 227                 free(opts->strategy);
 228                 opts->strategy = xstrdup(buf.buf);
 229         }
 230
 231         if (file_exists(state_dir_path("strategy_opts", opts))) {
 232                 strbuf_reset(&buf);
 233                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 234                         return -1;
 235                 free(opts->strategy_opts);
 236                 opts->strategy_opts = xstrdup(buf.buf);
 237         }
 238
 239         strbuf_release(&buf);
 240
 241         return 0;
 242 }
 243
 244 static int apply_autostash(struct rebase_options *opts)
 245 {
 246         const char *path = state_dir_path("autostash", opts);
 247         struct strbuf autostash = STRBUF_INIT;
 248         struct child_process stash_apply = CHILD_PROCESS_INIT;
 249
 250         if (!file_exists(path))
 251                 return 0;
 252
 253         if (read_one(state_dir_path("autostash", opts), &autostash))
 254                 return error(_("Could not read '%s'"), path);
 255         argv_array_pushl(&stash_apply.args,
 256                          "stash", "apply", autostash.buf, NULL);
 257         stash_apply.git_cmd = 1;
 258         stash_apply.no_stderr = stash_apply.no_stdout =
 259                 stash_apply.no_stdin = 1;
 260         if (!run_command(&stash_apply))
 261                 printf(_("Applied autostash.\n"));
 262         else {
 263                 struct argv_array args = ARGV_ARRAY_INIT;
 264                 int res = 0;
 265
 266                 argv_array_pushl(&args,
 267                                  "stash", "store", "-m", "autostash", "-q",
 268                                  autostash.buf, NULL);
 269                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 270                         res = error(_("Cannot store %s"), autostash.buf);
 271                 argv_array_clear(&args);
 272                 strbuf_release(&autostash);
 273                 if (res)
 274                         return res;
 275
 276                 fprintf(stderr,
 277                         _("Applying autostash resulted in conflicts.\n"
 278                           "Your changes are safe in the stash.\n"
 279                           "You can run \"git stash pop\" or \"git stash drop\" "
 280                           "at any time.\n"));
 281         }
 282
 283         strbuf_release(&autostash);
 284         return 0;
 285 }
 286
 287 static int finish_rebase(struct rebase_options *opts)
 288 {
 289         struct strbuf dir = STRBUF_INIT;
 290         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 291
 292         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 293         apply_autostash(opts);
 294         close_all_packs(the_repository->objects);
 295         /*
 296          * We ignore errors in 'gc --auto', since the
 297          * user should see them.
 298          */
 299         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 300         strbuf_addstr(&dir, opts->state_dir);
 301         remove_dir_recursively(&dir, 0);
 302         strbuf_release(&dir);
 303
 304         return 0;
 305 }
 306
 307 static struct commit *peel_committish(const char *name)
 308 {
 309         struct object *obj;
 310         struct object_id oid;
 311
 312         if (get_oid(name, &oid))
 313                 return NULL;
 314         obj = parse_object(the_repository, &oid);
 315         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 316 }
 317
 318 static void add_var(struct strbuf *buf, const char *name, const char *value)
 319 {
 320         if (!value)
 321                 strbuf_addf(buf, "unset %s; ", name);
 322         else {
 323                 strbuf_addf(buf, "%s=", name);
 324                 sq_quote_buf(buf, value);
 325                 strbuf_addstr(buf, "; ");
 326         }
 327 }
 328
 329 static const char *resolvemsg =
 330 N_("Resolve all conflicts manually, mark them as resolved with\n"
 331 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 332 "You can instead skip this commit: run \"git rebase --skip\".\n"
 333 "To abort and get back to the state before \"git rebase\", run "
 334 "\"git rebase --abort\".");
 335
 336 static int run_specific_rebase(struct rebase_options *opts)
 337 {
 338         const char *argv[] = { NULL, NULL };
 339         struct strbuf script_snippet = STRBUF_INIT;
 340         int status;
 341         const char *backend, *backend_func;
 342
 343         if (opts->type == REBASE_INTERACTIVE) {
 344                 /* Run builtin interactive rebase */
 345                 struct child_process child = CHILD_PROCESS_INIT;
 346
 347                 argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 348                                  resolvemsg);
 349                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 350                         argv_array_push(&child.env_array, "GIT_EDITOR=:");
 351                         opts->autosquash = 0;
 352                 }
 353
 354                 child.git_cmd = 1;
 355                 argv_array_push(&child.args, "rebase--interactive");
 356
 357                 if (opts->action)
 358                         argv_array_pushf(&child.args, "--%s", opts->action);
 359                 if (opts->keep_empty)
 360                         argv_array_push(&child.args, "--keep-empty");
 361                 if (opts->rebase_merges)
 362                         argv_array_push(&child.args, "--rebase-merges");
 363                 if (opts->rebase_cousins)
 364                         argv_array_push(&child.args, "--rebase-cousins");
 365                 if (opts->autosquash)
 366                         argv_array_push(&child.args, "--autosquash");
 367                 if (opts->flags & REBASE_VERBOSE)
 368                         argv_array_push(&child.args, "--verbose");
 369                 if (opts->flags & REBASE_FORCE)
 370                         argv_array_push(&child.args, "--no-ff");
 371                 if (opts->restrict_revision)
 372                         argv_array_pushf(&child.args,
 373                                          "--restrict-revision=^%s",
 374                                          oid_to_hex(&opts->restrict_revision->object.oid));
 375                 if (opts->upstream)
 376                         argv_array_pushf(&child.args, "--upstream=%s",
 377                                          oid_to_hex(&opts->upstream->object.oid));
 378                 if (opts->onto)
 379                         argv_array_pushf(&child.args, "--onto=%s",
 380                                          oid_to_hex(&opts->onto->object.oid));
 381                 if (opts->squash_onto)
 382                         argv_array_pushf(&child.args, "--squash-onto=%s",
 383                                          oid_to_hex(opts->squash_onto));
 384                 if (opts->onto_name)
 385                         argv_array_pushf(&child.args, "--onto-name=%s",
 386                                          opts->onto_name);
 387                 argv_array_pushf(&child.args, "--head-name=%s",
 388                                  opts->head_name ?
 389                                  opts->head_name : "detached HEAD");
 390                 if (opts->strategy)
 391                         argv_array_pushf(&child.args, "--strategy=%s",
 392                                          opts->strategy);
 393                 if (opts->strategy_opts)
 394                         argv_array_pushf(&child.args, "--strategy-opts=%s",
 395                                          opts->strategy_opts);
 396                 if (opts->switch_to)
 397                         argv_array_pushf(&child.args, "--switch-to=%s",
 398                                          opts->switch_to);
 399                 if (opts->cmd)
 400                         argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
 401                 if (opts->allow_empty_message)
 402                         argv_array_push(&child.args, "--allow-empty-message");
 403                 if (opts->allow_rerere_autoupdate > 0)
 404                         argv_array_push(&child.args, "--rerere-autoupdate");
 405                 else if (opts->allow_rerere_autoupdate == 0)
 406                         argv_array_push(&child.args, "--no-rerere-autoupdate");
 407                 if (opts->gpg_sign_opt)
 408                         argv_array_push(&child.args, opts->gpg_sign_opt);
 409                 if (opts->signoff)
 410                         argv_array_push(&child.args, "--signoff");
 411
 412                 status = run_command(&child);
 413                 goto finished_rebase;
 414         }
 415
 416         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 417         add_var(&script_snippet, "state_dir", opts->state_dir);
 418
 419         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 420         add_var(&script_snippet, "upstream", opts->upstream ?
 421                 oid_to_hex(&opts->upstream->object.oid) : NULL);
 422         add_var(&script_snippet, "head_name",
 423                 opts->head_name ? opts->head_name : "detached HEAD");
 424         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 425         add_var(&script_snippet, "onto", opts->onto ?
 426                 oid_to_hex(&opts->onto->object.oid) : NULL);
 427         add_var(&script_snippet, "onto_name", opts->onto_name);
 428         add_var(&script_snippet, "revisions", opts->revisions);
 429         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 430                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 431         add_var(&script_snippet, "GIT_QUIET",
 432                 opts->flags & REBASE_NO_QUIET ? "" : "t");
 433         add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
 434         add_var(&script_snippet, "verbose",
 435                 opts->flags & REBASE_VERBOSE ? "t" : "");
 436         add_var(&script_snippet, "diffstat",
 437                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
 438         add_var(&script_snippet, "force_rebase",
 439                 opts->flags & REBASE_FORCE ? "t" : "");
 440         if (opts->switch_to)
 441                 add_var(&script_snippet, "switch_to", opts->switch_to);
 442         add_var(&script_snippet, "action", opts->action ? opts->action : "");
 443         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 444         add_var(&script_snippet, "allow_rerere_autoupdate",
 445                 opts->allow_rerere_autoupdate < 0 ? "" :
 446                 opts->allow_rerere_autoupdate ?
 447                 "--rerere-autoupdate" : "--no-rerere-autoupdate");
 448         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 449         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 450         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 451         add_var(&script_snippet, "cmd", opts->cmd);
 452         add_var(&script_snippet, "allow_empty_message",
 453                 opts->allow_empty_message ?  "--allow-empty-message" : "");
 454         add_var(&script_snippet, "rebase_merges",
 455                 opts->rebase_merges ? "t" : "");
 456         add_var(&script_snippet, "rebase_cousins",
 457                 opts->rebase_cousins ? "t" : "");
 458         add_var(&script_snippet, "strategy", opts->strategy);
 459         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 460         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 461         add_var(&script_snippet, "squash_onto",
 462                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 463         add_var(&script_snippet, "git_format_patch_opt",
 464                 opts->git_format_patch_opt.buf);
 465
 466         if (is_interactive(opts) &&
 467             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 468                 strbuf_addstr(&script_snippet,
 469                               "GIT_EDITOR=:; export GIT_EDITOR; ");
 470                 opts->autosquash = 0;
 471         }
 472
 473         switch (opts->type) {
 474         case REBASE_AM:
 475                 backend = "git-rebase--am";
 476                 backend_func = "git_rebase__am";
 477                 break;
 478         case REBASE_MERGE:
 479                 backend = "git-rebase--merge";
 480                 backend_func = "git_rebase__merge";
 481                 break;
 482         case REBASE_PRESERVE_MERGES:
 483                 backend = "git-rebase--preserve-merges";
 484                 backend_func = "git_rebase__preserve_merges";
 485                 break;
 486         default:
 487                 BUG("Unhandled rebase type %d", opts->type);
 488                 break;
 489         }
 490
 491         strbuf_addf(&script_snippet,
 492                     ". git-sh-setup && . git-rebase--common &&"
 493                     " . %s && %s", backend, backend_func);
 494         argv[0] = script_snippet.buf;
 495
 496         status = run_command_v_opt(argv, RUN_USING_SHELL);
 497 finished_rebase:
 498         if (opts->dont_finish_rebase)
 499                 ; /* do nothing */
 500         else if (opts->type == REBASE_INTERACTIVE)
 501                 ; /* interactive rebase cleans up after itself */
 502         else if (status == 0) {
 503                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 504                         finish_rebase(opts);
 505         } else if (status == 2) {
 506                 struct strbuf dir = STRBUF_INIT;
 507
 508                 apply_autostash(opts);
 509                 strbuf_addstr(&dir, opts->state_dir);
 510                 remove_dir_recursively(&dir, 0);
 511                 strbuf_release(&dir);
 512                 die("Nothing to do");
 513         }
 514
 515         strbuf_release(&script_snippet);
 516
 517         return status ? -1 : 0;
 518 }
 519
 520 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 521
 522 static int reset_head(struct object_id *oid, const char *action,
 523                       const char *switch_to_branch, int detach_head,
 524                       const char *reflog_orig_head, const char *reflog_head)
 525 {
 526         struct object_id head_oid;
 527         struct tree_desc desc;
 528         struct lock_file lock = LOCK_INIT;
 529         struct unpack_trees_options unpack_tree_opts;
 530         struct tree *tree;
 531         const char *reflog_action;
 532         struct strbuf msg = STRBUF_INIT;
 533         size_t prefix_len;
 534         struct object_id *orig = NULL, oid_orig,
 535                 *old_orig = NULL, oid_old_orig;
 536         int ret = 0;
 537
 538         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 539                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 540
 541         if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 542                 return -1;
 543
 544         if (!oid) {
 545                 if (get_oid("HEAD", &head_oid)) {
 546                         rollback_lock_file(&lock);
 547                         return error(_("could not determine HEAD revision"));
 548                 }
 549                 oid = &head_oid;
 550         }
 551
 552         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 553         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 554         unpack_tree_opts.head_idx = 1;
 555         unpack_tree_opts.src_index = the_repository->index;
 556         unpack_tree_opts.dst_index = the_repository->index;
 557         unpack_tree_opts.fn = oneway_merge;
 558         unpack_tree_opts.update = 1;
 559         unpack_tree_opts.merge = 1;
 560         if (!detach_head)
 561                 unpack_tree_opts.reset = 1;
 562
 563         if (read_index_unmerged(the_repository->index) < 0) {
 564                 rollback_lock_file(&lock);
 565                 return error(_("could not read index"));
 566         }
 567
 568         if (!fill_tree_descriptor(&desc, oid)) {
 569                 error(_("failed to find tree of %s"), oid_to_hex(oid));
 570                 rollback_lock_file(&lock);
 571                 free((void *)desc.buffer);
 572                 return -1;
 573         }
 574
 575         if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 576                 rollback_lock_file(&lock);
 577                 free((void *)desc.buffer);
 578                 return -1;
 579         }
 580
 581         tree = parse_tree_indirect(oid);
 582         prime_cache_tree(the_repository->index, tree);
 583
 584         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 585                 ret = error(_("could not write index"));
 586         free((void *)desc.buffer);
 587
 588         if (ret)
 589                 return ret;
 590
 591         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 592         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 593         prefix_len = msg.len;
 594
 595         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 596                 old_orig = &oid_old_orig;
 597         if (!get_oid("HEAD", &oid_orig)) {
 598                 orig = &oid_orig;
 599                 if (!reflog_orig_head) {
 600                         strbuf_addstr(&msg, "updating ORIG_HEAD");
 601                         reflog_orig_head = msg.buf;
 602                 }
 603                 update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
 604                            UPDATE_REFS_MSG_ON_ERR);
 605         } else if (old_orig)
 606                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 607         if (!reflog_head) {
 608                 strbuf_setlen(&msg, prefix_len);
 609                 strbuf_addstr(&msg, "updating HEAD");
 610                 reflog_head = msg.buf;
 611         }
 612         if (!switch_to_branch)
 613                 ret = update_ref(reflog_head, "HEAD", oid, orig, REF_NO_DEREF,
 614                                  UPDATE_REFS_MSG_ON_ERR);
 615         else {
 616                 ret = create_symref("HEAD", switch_to_branch, msg.buf);
 617                 if (!ret)
 618                         ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 619                                          UPDATE_REFS_MSG_ON_ERR);
 620         }
 621
 622         strbuf_release(&msg);
 623         return ret;
 624 }
 625
 626 static int rebase_config(const char *var, const char *value, void *data)
 627 {
 628         struct rebase_options *opts = data;
 629
 630         if (!strcmp(var, "rebase.stat")) {
 631                 if (git_config_bool(var, value))
 632                         opts->flags |= REBASE_DIFFSTAT;
 633                 else
 634                         opts->flags &= !REBASE_DIFFSTAT;
 635                 return 0;
 636         }
 637
 638         if (!strcmp(var, "rebase.autosquash")) {
 639                 opts->autosquash = git_config_bool(var, value);
 640                 return 0;
 641         }
 642
 643         if (!strcmp(var, "commit.gpgsign")) {
 644                 free(opts->gpg_sign_opt);
 645                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 646                         xstrdup("-S") : NULL;
 647                 return 0;
 648         }
 649
 650         if (!strcmp(var, "rebase.autostash")) {
 651                 opts->autostash = git_config_bool(var, value);
 652                 return 0;
 653         }
 654
 655         return git_default_config(var, value, data);
 656 }
 657
 658 /*
 659  * Determines whether the commits in from..to are linear, i.e. contain
 660  * no merge commits. This function *expects* `from` to be an ancestor of
 661  * `to`.
 662  */
 663 static int is_linear_history(struct commit *from, struct commit *to)
 664 {
 665         while (to && to != from) {
 666                 parse_commit(to);
 667                 if (!to->parents)
 668                         return 1;
 669                 if (to->parents->next)
 670                         return 0;
 671                 to = to->parents->item;
 672         }
 673         return 1;
 674 }
 675
 676 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 677                             struct object_id *merge_base)
 678 {
 679         struct commit *head = lookup_commit(the_repository, head_oid);
 680         struct commit_list *merge_bases;
 681         int res;
 682
 683         if (!head)
 684                 return 0;
 685
 686         merge_bases = get_merge_bases(onto, head);
 687         if (merge_bases && !merge_bases->next) {
 688                 oidcpy(merge_base, &merge_bases->item->object.oid);
 689                 res = !oidcmp(merge_base, &onto->object.oid);
 690         } else {
 691                 oidcpy(merge_base, &null_oid);
 692                 res = 0;
 693         }
 694         free_commit_list(merge_bases);
 695         return res && is_linear_history(onto, head);
 696 }
 697
 698 /* -i followed by -m is still -i */
 699 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 700 {
 701         struct rebase_options *opts = opt->value;
 702
 703         if (!is_interactive(opts))
 704                 opts->type = REBASE_MERGE;
 705
 706         return 0;
 707 }
 708
 709 /* -i followed by -p is still explicitly interactive, but -p alone is not */
 710 static int parse_opt_interactive(const struct option *opt, const char *arg,
 711                                  int unset)
 712 {
 713         struct rebase_options *opts = opt->value;
 714
 715         opts->type = REBASE_INTERACTIVE;
 716         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 717
 718         return 0;
 719 }
 720
 721 static void NORETURN error_on_missing_default_upstream(void)
 722 {
 723         struct branch *current_branch = branch_get(NULL);
 724
 725         printf(_("%s\n"
 726                  "Please specify which branch you want to rebase against.\n"
 727                  "See git-rebase(1) for details.\n"
 728                  "\n"
 729                  "    git rebase '<branch>'\n"
 730                  "\n"),
 731                 current_branch ? _("There is no tracking information for "
 732                         "the current branch.") :
 733                         _("You are not currently on a branch."));
 734
 735         if (current_branch) {
 736                 const char *remote = current_branch->remote_name;
 737
 738                 if (!remote)
 739                         remote = _("<remote>");
 740
 741                 printf(_("If you wish to set tracking information for this "
 742                          "branch you can do so with:\n"
 743                          "\n"
 744                          "    git branch --set-upstream-to=%s/<branch> %s\n"
 745                          "\n"),
 746                        remote, current_branch->name);
 747         }
 748         exit(1);
 749 }
 750
 751 int cmd_rebase(int argc, const char **argv, const char *prefix)
 752 {
 753         struct rebase_options options = {
 754                 .type = REBASE_UNSPECIFIED,
 755                 .flags = REBASE_NO_QUIET,
 756                 .git_am_opt = STRBUF_INIT,
 757                 .allow_rerere_autoupdate  = -1,
 758                 .allow_empty_message = 1,
 759                 .git_format_patch_opt = STRBUF_INIT,
 760         };
 761         const char *branch_name;
 762         int ret, flags, total_argc, in_progress = 0;
 763         int ok_to_skip_pre_rebase = 0;
 764         struct strbuf msg = STRBUF_INIT;
 765         struct strbuf revisions = STRBUF_INIT;
 766         struct strbuf buf = STRBUF_INIT;
 767         struct object_id merge_base;
 768         enum {
 769                 NO_ACTION,
 770                 ACTION_CONTINUE,
 771                 ACTION_SKIP,
 772                 ACTION_ABORT,
 773                 ACTION_QUIT,
 774                 ACTION_EDIT_TODO,
 775                 ACTION_SHOW_CURRENT_PATCH,
 776         } action = NO_ACTION;
 777         int committer_date_is_author_date = 0;
 778         int ignore_date = 0;
 779         int ignore_whitespace = 0;
 780         const char *gpg_sign = NULL;
 781         int opt_c = -1;
 782         struct string_list whitespace = STRING_LIST_INIT_NODUP;
 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, "ignore-whitespace", &ignore_whitespace,
 805                          N_("passed to 'git apply'")),
 806                 OPT_BOOL(0, "signoff", &options.signoff,
 807                          N_("add a Signed-off-by: line to each commit")),
 808                 OPT_BOOL(0, "committer-date-is-author-date",
 809                          &committer_date_is_author_date,
 810                          N_("passed to 'git am'")),
 811                 OPT_BOOL(0, "ignore-date", &ignore_date,
 812                          N_("passed to 'git am'")),
 813                 OPT_BIT('f', "force-rebase", &options.flags,
 814                         N_("cherry-pick all commits, even if unchanged"),
 815                         REBASE_FORCE),
 816                 OPT_BIT(0, "no-ff", &options.flags,
 817                         N_("cherry-pick all commits, even if unchanged"),
 818                         REBASE_FORCE),
 819                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
 820                             ACTION_CONTINUE),
 821                 OPT_CMDMODE(0, "skip", &action,
 822                             N_("skip current patch and continue"), ACTION_SKIP),
 823                 OPT_CMDMODE(0, "abort", &action,
 824                             N_("abort and check out the original branch"),
 825                             ACTION_ABORT),
 826                 OPT_CMDMODE(0, "quit", &action,
 827                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
 828                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 829                             "during an interactive rebase"), ACTION_EDIT_TODO),
 830                 OPT_CMDMODE(0, "show-current-patch", &action,
 831                             N_("show the patch file being applied or merged"),
 832                             ACTION_SHOW_CURRENT_PATCH),
 833                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 834                         N_("use merging strategies to rebase"),
 835                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 836                         parse_opt_merge },
 837                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 838                         N_("let the user edit the list of commits to rebase"),
 839                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 840                         parse_opt_interactive },
 841                 OPT_SET_INT('p', "preserve-merges", &options.type,
 842                             N_("try to recreate merges instead of ignoring "
 843                                "them"), REBASE_PRESERVE_MERGES),
 844                 OPT_BOOL(0, "rerere-autoupdate",
 845                          &options.allow_rerere_autoupdate,
 846                          N_("allow rerere to update index  with resolved "
 847                             "conflict")),
 848                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
 849                          N_("preserve empty commits during rebase")),
 850                 OPT_BOOL(0, "autosquash", &options.autosquash,
 851                          N_("move commits that begin with "
 852                             "squash!/fixup! under -i")),
 853                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 854                         N_("GPG-sign commits"),
 855                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 856                 OPT_STRING_LIST(0, "whitespace", &whitespace,
 857                                 N_("whitespace"), N_("passed to 'git apply'")),
 858                 OPT_SET_INT('C', NULL, &opt_c, N_("passed to 'git apply'"),
 859                             REBASE_AM),
 860                 OPT_BOOL(0, "autostash", &options.autostash,
 861                          N_("automatically stash/stash pop before and after")),
 862                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 863                                 N_("add exec lines after each commit of the "
 864                                    "editable list")),
 865                 OPT_BOOL(0, "allow-empty-message",
 866                          &options.allow_empty_message,
 867                          N_("allow rebasing commits with empty messages")),
 868                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 869                         N_("mode"),
 870                         N_("try to rebase merges instead of skipping them"),
 871                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 872                 OPT_BOOL(0, "fork-point", &fork_point,
 873                          N_("use 'merge-base --fork-point' to refine upstream")),
 874                 OPT_STRING('s', "strategy", &options.strategy,
 875                            N_("strategy"), N_("use the given merge strategy")),
 876                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 877                                 N_("option"),
 878                                 N_("pass the argument through to the merge "
 879                                    "strategy")),
 880                 OPT_BOOL(0, "root", &options.root,
 881                          N_("rebase all reachable commits up to the root(s)")),
 882                 OPT_END(),
 883         };
 884
 885         /*
 886          * NEEDSWORK: Once the builtin rebase has been tested enough
 887          * and git-legacy-rebase.sh is retired to contrib/, this preamble
 888          * can be removed.
 889          */
 890
 891         if (!use_builtin_rebase()) {
 892                 const char *path = mkpath("%s/git-legacy-rebase",
 893                                           git_exec_path());
 894
 895                 if (sane_execvp(path, (char **)argv) < 0)
 896                         die_errno(_("could not exec %s"), path);
 897                 else
 898                         BUG("sane_execvp() returned???");
 899         }
 900
 901         if (argc == 2 && !strcmp(argv[1], "-h"))
 902                 usage_with_options(builtin_rebase_usage,
 903                                    builtin_rebase_options);
 904
 905         prefix = setup_git_directory();
 906         trace_repo_setup(prefix);
 907         setup_work_tree();
 908
 909         git_config(rebase_config, &options);
 910
 911         strbuf_reset(&buf);
 912         strbuf_addf(&buf, "%s/applying", apply_dir());
 913         if(file_exists(buf.buf))
 914                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
 915
 916         if (is_directory(apply_dir())) {
 917                 options.type = REBASE_AM;
 918                 options.state_dir = apply_dir();
 919         } else if (is_directory(merge_dir())) {
 920                 strbuf_reset(&buf);
 921                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
 922                 if (is_directory(buf.buf)) {
 923                         options.type = REBASE_PRESERVE_MERGES;
 924                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 925                 } else {
 926                         strbuf_reset(&buf);
 927                         strbuf_addf(&buf, "%s/interactive", merge_dir());
 928                         if(file_exists(buf.buf)) {
 929                                 options.type = REBASE_INTERACTIVE;
 930                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 931                         } else
 932                                 options.type = REBASE_MERGE;
 933                 }
 934                 options.state_dir = merge_dir();
 935         }
 936
 937         if (options.type != REBASE_UNSPECIFIED)
 938                 in_progress = 1;
 939
 940         total_argc = argc;
 941         argc = parse_options(argc, argv, prefix,
 942                              builtin_rebase_options,
 943                              builtin_rebase_usage, 0);
 944
 945         if (action != NO_ACTION && total_argc != 2) {
 946                 usage_with_options(builtin_rebase_usage,
 947                                    builtin_rebase_options);
 948         }
 949
 950         if (argc > 2)
 951                 usage_with_options(builtin_rebase_usage,
 952                                    builtin_rebase_options);
 953
 954         if (action != NO_ACTION && !in_progress)
 955                 die(_("No rebase in progress?"));
 956
 957         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 958                 die(_("The --edit-todo action can only be used during "
 959                       "interactive rebase."));
 960
 961         switch (action) {
 962         case ACTION_CONTINUE: {
 963                 struct object_id head;
 964                 struct lock_file lock_file = LOCK_INIT;
 965                 int fd;
 966
 967                 options.action = "continue";
 968
 969                 /* Sanity check */
 970                 if (get_oid("HEAD", &head))
 971                         die(_("Cannot read HEAD"));
 972
 973                 fd = hold_locked_index(&lock_file, 0);
 974                 if (read_index(the_repository->index) < 0)
 975                         die(_("could not read index"));
 976                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
 977                               NULL);
 978                 if (0 <= fd)
 979                         update_index_if_able(the_repository->index,
 980                                              &lock_file);
 981                 rollback_lock_file(&lock_file);
 982
 983                 if (has_unstaged_changes(1)) {
 984                         puts(_("You must edit all merge conflicts and then\n"
 985                                "mark them as resolved using git add"));
 986                         exit(1);
 987                 }
 988                 if (read_basic_state(&options))
 989                         exit(1);
 990                 goto run_rebase;
 991         }
 992         case ACTION_SKIP: {
 993                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
 994
 995                 options.action = "skip";
 996
 997                 rerere_clear(&merge_rr);
 998                 string_list_clear(&merge_rr, 1);
 999
1000                 if (reset_head(NULL, "reset", NULL, 0, NULL, NULL) < 0)
1001                         die(_("could not discard worktree changes"));
1002                 if (read_basic_state(&options))
1003                         exit(1);
1004                 goto run_rebase;
1005         }
1006         case ACTION_ABORT: {
1007                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1008                 options.action = "abort";
1009
1010                 rerere_clear(&merge_rr);
1011                 string_list_clear(&merge_rr, 1);
1012
1013                 if (read_basic_state(&options))
1014                         exit(1);
1015                 if (reset_head(&options.orig_head, "reset",
1016                                options.head_name, 0, NULL, NULL) < 0)
1017                         die(_("could not move back to %s"),
1018                             oid_to_hex(&options.orig_head));
1019                 ret = finish_rebase(&options);
1020                 goto cleanup;
1021         }
1022         case ACTION_QUIT: {
1023                 strbuf_reset(&buf);
1024                 strbuf_addstr(&buf, options.state_dir);
1025                 ret = !!remove_dir_recursively(&buf, 0);
1026                 if (ret)
1027                         die(_("could not remove '%s'"), options.state_dir);
1028                 goto cleanup;
1029         }
1030         case ACTION_EDIT_TODO:
1031                 options.action = "edit-todo";
1032                 options.dont_finish_rebase = 1;
1033                 goto run_rebase;
1034         case ACTION_SHOW_CURRENT_PATCH:
1035                 options.action = "show-current-patch";
1036                 options.dont_finish_rebase = 1;
1037                 goto run_rebase;
1038         case NO_ACTION:
1039                 break;
1040         default:
1041                 BUG("action: %d", action);
1042         }
1043
1044         /* Make sure no rebase is in progress */
1045         if (in_progress) {
1046                 const char *last_slash = strrchr(options.state_dir, '/');
1047                 const char *state_dir_base =
1048                         last_slash ? last_slash + 1 : options.state_dir;
1049                 const char *cmd_live_rebase =
1050                         "git rebase (--continue | --abort | --skip)";
1051                 strbuf_reset(&buf);
1052                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1053                 die(_("It seems that there is already a %s directory, and\n"
1054                       "I wonder if you are in the middle of another rebase.  "
1055                       "If that is the\n"
1056                       "case, please try\n\t%s\n"
1057                       "If that is not the case, please\n\t%s\n"
1058                       "and run me again.  I am stopping in case you still "
1059                       "have something\n"
1060                       "valuable there.\n"),
1061                     state_dir_base, cmd_live_rebase, buf.buf);
1062         }
1063
1064         if (!(options.flags & REBASE_NO_QUIET))
1065                 strbuf_addstr(&options.git_am_opt, " -q");
1066
1067         if (committer_date_is_author_date) {
1068                 strbuf_addstr(&options.git_am_opt,
1069                               " --committer-date-is-author-date");
1070                 options.flags |= REBASE_FORCE;
1071         }
1072
1073         if (ignore_whitespace)
1074                 strbuf_addstr(&options.git_am_opt, " --ignore-whitespace");
1075
1076         if (ignore_date) {
1077                 strbuf_addstr(&options.git_am_opt, " --ignore-date");
1078                 options.flags |= REBASE_FORCE;
1079         }
1080
1081         if (options.keep_empty)
1082                 imply_interactive(&options, "--keep-empty");
1083
1084         if (gpg_sign) {
1085                 free(options.gpg_sign_opt);
1086                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1087         }
1088
1089         if (opt_c >= 0)
1090                 strbuf_addf(&options.git_am_opt, " -C%d", opt_c);
1091
1092         if (whitespace.nr) {
1093                 int i;
1094
1095                 for (i = 0; i < whitespace.nr; i++) {
1096                         const char *item = whitespace.items[i].string;
1097
1098                         strbuf_addf(&options.git_am_opt, " --whitespace=%s",
1099                                     item);
1100
1101                         if ((!strcmp(item, "fix")) || (!strcmp(item, "strip")))
1102                                 options.flags |= REBASE_FORCE;
1103                 }
1104         }
1105
1106         if (exec.nr) {
1107                 int i;
1108
1109                 imply_interactive(&options, "--exec");
1110
1111                 strbuf_reset(&buf);
1112                 for (i = 0; i < exec.nr; i++)
1113                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1114                 options.cmd = xstrdup(buf.buf);
1115         }
1116
1117         if (rebase_merges) {
1118                 if (!*rebase_merges)
1119                         ; /* default mode; do nothing */
1120                 else if (!strcmp("rebase-cousins", rebase_merges))
1121                         options.rebase_cousins = 1;
1122                 else if (strcmp("no-rebase-cousins", rebase_merges))
1123                         die(_("Unknown mode: %s"), rebase_merges);
1124                 options.rebase_merges = 1;
1125                 imply_interactive(&options, "--rebase-merges");
1126         }
1127
1128         if (strategy_options.nr) {
1129                 int i;
1130
1131                 if (!options.strategy)
1132                         options.strategy = "recursive";
1133
1134                 strbuf_reset(&buf);
1135                 for (i = 0; i < strategy_options.nr; i++)
1136                         strbuf_addf(&buf, " --%s",
1137                                     strategy_options.items[i].string);
1138                 options.strategy_opts = xstrdup(buf.buf);
1139         }
1140
1141         if (options.strategy) {
1142                 options.strategy = xstrdup(options.strategy);
1143                 switch (options.type) {
1144                 case REBASE_AM:
1145                         die(_("--strategy requires --merge or --interactive"));
1146                 case REBASE_MERGE:
1147                 case REBASE_INTERACTIVE:
1148                 case REBASE_PRESERVE_MERGES:
1149                         /* compatible */
1150                         break;
1151                 case REBASE_UNSPECIFIED:
1152                         options.type = REBASE_MERGE;
1153                         break;
1154                 default:
1155                         BUG("unhandled rebase type (%d)", options.type);
1156                 }
1157         }
1158
1159         if (options.root && !options.onto_name)
1160                 imply_interactive(&options, "--root without --onto");
1161
1162         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1163                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1164
1165         switch (options.type) {
1166         case REBASE_MERGE:
1167         case REBASE_INTERACTIVE:
1168         case REBASE_PRESERVE_MERGES:
1169                 options.state_dir = merge_dir();
1170                 break;
1171         case REBASE_AM:
1172                 options.state_dir = apply_dir();
1173                 break;
1174         default:
1175                 /* the default rebase backend is `--am` */
1176                 options.type = REBASE_AM;
1177                 options.state_dir = apply_dir();
1178                 break;
1179         }
1180
1181         if (options.git_am_opt.len) {
1182                 const char *p;
1183
1184                 /* all am options except -q are compatible only with --am */
1185                 strbuf_reset(&buf);
1186                 strbuf_addbuf(&buf, &options.git_am_opt);
1187                 strbuf_addch(&buf, ' ');
1188                 while ((p = strstr(buf.buf, " -q ")))
1189                         strbuf_splice(&buf, p - buf.buf, 4, " ", 1);
1190                 strbuf_trim(&buf);
1191
1192                 if (is_interactive(&options) && buf.len)
1193                         die(_("error: cannot combine interactive options "
1194                               "(--interactive, --exec, --rebase-merges, "
1195                               "--preserve-merges, --keep-empty, --root + "
1196                               "--onto) with am options (%s)"), buf.buf);
1197                 if (options.type == REBASE_MERGE && buf.len)
1198                         die(_("error: cannot combine merge options (--merge, "
1199                               "--strategy, --strategy-option) with am options "
1200                               "(%s)"), buf.buf);
1201         }
1202
1203         if (options.signoff) {
1204                 if (options.type == REBASE_PRESERVE_MERGES)
1205                         die("cannot combine '--signoff' with "
1206                             "'--preserve-merges'");
1207                 strbuf_addstr(&options.git_am_opt, " --signoff");
1208                 options.flags |= REBASE_FORCE;
1209         }
1210
1211         if (options.type == REBASE_PRESERVE_MERGES)
1212                 /*
1213                  * Note: incompatibility with --signoff handled in signoff block above
1214                  * Note: incompatibility with --interactive is just a strong warning;
1215                  *       git-rebase.txt caveats with "unless you know what you are doing"
1216                  */
1217                 if (options.rebase_merges)
1218                         die(_("error: cannot combine '--preserve_merges' with "
1219                               "'--rebase-merges'"));
1220
1221         if (options.rebase_merges) {
1222                 if (strategy_options.nr)
1223                         die(_("error: cannot combine '--rebase_merges' with "
1224                               "'--strategy-option'"));
1225                 if (options.strategy)
1226                         die(_("error: cannot combine '--rebase_merges' with "
1227                               "'--strategy'"));
1228         }
1229
1230         if (!options.root) {
1231                 if (argc < 1) {
1232                         struct branch *branch;
1233
1234                         branch = branch_get(NULL);
1235                         options.upstream_name = branch_get_upstream(branch,
1236                                                                     NULL);
1237                         if (!options.upstream_name)
1238                                 error_on_missing_default_upstream();
1239                         if (fork_point < 0)
1240                                 fork_point = 1;
1241                 } else {
1242                         options.upstream_name = argv[0];
1243                         argc--;
1244                         argv++;
1245                         if (!strcmp(options.upstream_name, "-"))
1246                                 options.upstream_name = "@{-1}";
1247                 }
1248                 options.upstream = peel_committish(options.upstream_name);
1249                 if (!options.upstream)
1250                         die(_("invalid upstream '%s'"), options.upstream_name);
1251                 options.upstream_arg = options.upstream_name;
1252         } else {
1253                 if (!options.onto_name) {
1254                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1255                                         &squash_onto, NULL, NULL) < 0)
1256                                 die(_("Could not create new root commit"));
1257                         options.squash_onto = &squash_onto;
1258                         options.onto_name = squash_onto_name =
1259                                 xstrdup(oid_to_hex(&squash_onto));
1260                 }
1261                 options.upstream_name = NULL;
1262                 options.upstream = NULL;
1263                 if (argc > 1)
1264                         usage_with_options(builtin_rebase_usage,
1265                                            builtin_rebase_options);
1266                 options.upstream_arg = "--root";
1267         }
1268
1269         /* Make sure the branch to rebase onto is valid. */
1270         if (!options.onto_name)
1271                 options.onto_name = options.upstream_name;
1272         if (strstr(options.onto_name, "...")) {
1273                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
1274                         die(_("'%s': need exactly one merge base"),
1275                             options.onto_name);
1276                 options.onto = lookup_commit_or_die(&merge_base,
1277                                                     options.onto_name);
1278         } else {
1279                 options.onto = peel_committish(options.onto_name);
1280                 if (!options.onto)
1281                         die(_("Does not point to a valid commit '%s'"),
1282                                 options.onto_name);
1283         }
1284
1285         /*
1286          * If the branch to rebase is given, that is the branch we will rebase
1287          * branch_name -- branch/commit being rebased, or
1288          *                HEAD (already detached)
1289          * orig_head -- commit object name of tip of the branch before rebasing
1290          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1291          */
1292         if (argc == 1) {
1293                 /* Is it "rebase other branchname" or "rebase other commit"? */
1294                 branch_name = argv[0];
1295                 options.switch_to = argv[0];
1296
1297                 /* Is it a local branch? */
1298                 strbuf_reset(&buf);
1299                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1300                 if (!read_ref(buf.buf, &options.orig_head))
1301                         options.head_name = xstrdup(buf.buf);
1302                 /* If not is it a valid ref (branch or commit)? */
1303                 else if (!get_oid(branch_name, &options.orig_head))
1304                         options.head_name = NULL;
1305                 else
1306                         die(_("fatal: no such branch/commit '%s'"),
1307                             branch_name);
1308         } else if (argc == 0) {
1309                 /* Do not need to switch branches, we are already on it. */
1310                 options.head_name =
1311                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1312                                          &flags));
1313                 if (!options.head_name)
1314                         die(_("No such ref: %s"), "HEAD");
1315                 if (flags & REF_ISSYMREF) {
1316                         if (!skip_prefix(options.head_name,
1317                                          "refs/heads/", &branch_name))
1318                                 branch_name = options.head_name;
1319
1320                 } else {
1321                         free(options.head_name);
1322                         options.head_name = NULL;
1323                         branch_name = "HEAD";
1324                 }
1325                 if (get_oid("HEAD", &options.orig_head))
1326                         die(_("Could not resolve HEAD to a revision"));
1327         } else
1328                 BUG("unexpected number of arguments left to parse");
1329
1330         if (fork_point > 0) {
1331                 struct commit *head =
1332                         lookup_commit_reference(the_repository,
1333                                                 &options.orig_head);
1334                 options.restrict_revision =
1335                         get_fork_point(options.upstream_name, head);
1336         }
1337
1338         if (read_index(the_repository->index) < 0)
1339                 die(_("could not read index"));
1340
1341         if (options.autostash) {
1342                 struct lock_file lock_file = LOCK_INIT;
1343                 int fd;
1344
1345                 fd = hold_locked_index(&lock_file, 0);
1346                 refresh_cache(REFRESH_QUIET);
1347                 if (0 <= fd)
1348                         update_index_if_able(&the_index, &lock_file);
1349                 rollback_lock_file(&lock_file);
1350
1351                 if (has_unstaged_changes(0) || has_uncommitted_changes(0)) {
1352                         const char *autostash =
1353                                 state_dir_path("autostash", &options);
1354                         struct child_process stash = CHILD_PROCESS_INIT;
1355                         struct object_id oid;
1356                         struct commit *head =
1357                                 lookup_commit_reference(the_repository,
1358                                                         &options.orig_head);
1359
1360                         argv_array_pushl(&stash.args,
1361                                          "stash", "create", "autostash", NULL);
1362                         stash.git_cmd = 1;
1363                         stash.no_stdin = 1;
1364                         strbuf_reset(&buf);
1365                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1366                                 die(_("Cannot autostash"));
1367                         strbuf_trim_trailing_newline(&buf);
1368                         if (get_oid(buf.buf, &oid))
1369                                 die(_("Unexpected stash response: '%s'"),
1370                                     buf.buf);
1371                         strbuf_reset(&buf);
1372                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1373
1374                         if (safe_create_leading_directories_const(autostash))
1375                                 die(_("Could not create directory for '%s'"),
1376                                     options.state_dir);
1377                         write_file(autostash, "%s", buf.buf);
1378                         printf(_("Created autostash: %s\n"), buf.buf);
1379                         if (reset_head(&head->object.oid, "reset --hard",
1380                                        NULL, 0, NULL, NULL) < 0)
1381                                 die(_("could not reset --hard"));
1382                         printf(_("HEAD is now at %s"),
1383                                find_unique_abbrev(&head->object.oid,
1384                                                   DEFAULT_ABBREV));
1385                         strbuf_reset(&buf);
1386                         pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1387                         if (buf.len > 0)
1388                                 printf(" %s", buf.buf);
1389                         putchar('\n');
1390
1391                         if (discard_index(the_repository->index) < 0 ||
1392                                 read_index(the_repository->index) < 0)
1393                                 die(_("could not read index"));
1394                 }
1395         }
1396
1397         if (require_clean_work_tree("rebase",
1398                                     _("Please commit or stash them."), 1, 1)) {
1399                 ret = 1;
1400                 goto cleanup;
1401         }
1402
1403         /*
1404          * Now we are rebasing commits upstream..orig_head (or with --root,
1405          * everything leading up to orig_head) on top of onto.
1406          */
1407
1408         /*
1409          * Check if we are already based on onto with linear history,
1410          * but this should be done only when upstream and onto are the same
1411          * and if this is not an interactive rebase.
1412          */
1413         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1414             !is_interactive(&options) && !options.restrict_revision &&
1415             options.upstream &&
1416             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1417                 int flag;
1418
1419                 if (!(options.flags & REBASE_FORCE)) {
1420                         /* Lazily switch to the target branch if needed... */
1421                         if (options.switch_to) {
1422                                 struct object_id oid;
1423
1424                                 if (get_oid(options.switch_to, &oid) < 0) {
1425                                         ret = !!error(_("could not parse '%s'"),
1426                                                       options.switch_to);
1427                                         goto cleanup;
1428                                 }
1429
1430                                 strbuf_reset(&buf);
1431                                 strbuf_addf(&buf, "rebase: checkout %s",
1432                                             options.switch_to);
1433                                 if (reset_head(&oid, "checkout",
1434                                                options.head_name, 0,
1435                                                NULL, NULL) < 0) {
1436                                         ret = !!error(_("could not switch to "
1437                                                         "%s"),
1438                                                       options.switch_to);
1439                                         goto cleanup;
1440                                 }
1441                         }
1442
1443                         if (!(options.flags & REBASE_NO_QUIET))
1444                                 ; /* be quiet */
1445                         else if (!strcmp(branch_name, "HEAD") &&
1446                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1447                                 puts(_("HEAD is up to date."));
1448                         else
1449                                 printf(_("Current branch %s is up to date.\n"),
1450                                        branch_name);
1451                         ret = !!finish_rebase(&options);
1452                         goto cleanup;
1453                 } else if (!(options.flags & REBASE_NO_QUIET))
1454                         ; /* be quiet */
1455                 else if (!strcmp(branch_name, "HEAD") &&
1456                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1457                         puts(_("HEAD is up to date, rebase forced."));
1458                 else
1459                         printf(_("Current branch %s is up to date, rebase "
1460                                  "forced.\n"), branch_name);
1461         }
1462
1463         /* If a hook exists, give it a chance to interrupt*/
1464         if (!ok_to_skip_pre_rebase &&
1465             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1466                         argc ? argv[0] : NULL, NULL))
1467                 die(_("The pre-rebase hook refused to rebase."));
1468
1469         if (options.flags & REBASE_DIFFSTAT) {
1470                 struct diff_options opts;
1471
1472                 if (options.flags & REBASE_VERBOSE)
1473                         printf(_("Changes from %s to %s:\n"),
1474                                 oid_to_hex(&merge_base),
1475                                 oid_to_hex(&options.onto->object.oid));
1476
1477                 /* We want color (if set), but no pager */
1478                 diff_setup(&opts);
1479                 opts.stat_width = -1; /* use full terminal width */
1480                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1481                 opts.output_format |=
1482                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1483                 opts.detect_rename = DIFF_DETECT_RENAME;
1484                 diff_setup_done(&opts);
1485                 diff_tree_oid(&merge_base, &options.onto->object.oid,
1486                               "", &opts);
1487                 diffcore_std(&opts);
1488                 diff_flush(&opts);
1489         }
1490
1491         if (is_interactive(&options))
1492                 goto run_rebase;
1493
1494         /* Detach HEAD and reset the tree */
1495         if (options.flags & REBASE_NO_QUIET)
1496                 printf(_("First, rewinding head to replay your work on top of "
1497                          "it...\n"));
1498
1499         strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
1500         if (reset_head(&options.onto->object.oid, "checkout", NULL, 1,
1501             NULL, msg.buf))
1502                 die(_("Could not detach HEAD"));
1503         strbuf_release(&msg);
1504
1505         /*
1506          * If the onto is a proper descendant of the tip of the branch, then
1507          * we just fast-forwarded.
1508          */
1509         strbuf_reset(&msg);
1510         if (!oidcmp(&merge_base, &options.orig_head)) {
1511                 printf(_("Fast-forwarded %s to %s. \n"),
1512                         branch_name, options.onto_name);
1513                 strbuf_addf(&msg, "rebase finished: %s onto %s",
1514                         options.head_name ? options.head_name : "detached HEAD",
1515                         oid_to_hex(&options.onto->object.oid));
1516                 reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1517                            "HEAD", msg.buf);
1518                 strbuf_release(&msg);
1519                 ret = !!finish_rebase(&options);
1520                 goto cleanup;
1521         }
1522
1523         strbuf_addf(&revisions, "%s..%s",
1524                     options.root ? oid_to_hex(&options.onto->object.oid) :
1525                     (options.restrict_revision ?
1526                      oid_to_hex(&options.restrict_revision->object.oid) :
1527                      oid_to_hex(&options.upstream->object.oid)),
1528                     oid_to_hex(&options.orig_head));
1529
1530         options.revisions = revisions.buf;
1531
1532 run_rebase:
1533         ret = !!run_specific_rebase(&options);
1534
1535 cleanup:
1536         strbuf_release(&revisions);
1537         free(options.head_name);
1538         free(options.gpg_sign_opt);
1539         free(options.cmd);
1540         free(squash_onto_name);
1541         return ret;
1542 }