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 #include "branch.h"
  27
  28 static char const * const builtin_rebase_usage[] = {
  29         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  30                 "[<upstream>] [<branch>]"),
  31         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  32                 "--root [<branch>]"),
  33         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  34         NULL
  35 };
  36
  37 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  38 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  39
  40 enum rebase_type {
  41         REBASE_UNSPECIFIED = -1,
  42         REBASE_AM,
  43         REBASE_MERGE,
  44         REBASE_INTERACTIVE,
  45         REBASE_PRESERVE_MERGES
  46 };
  47
  48 static int use_builtin_rebase(void)
  49 {
  50         struct child_process cp = CHILD_PROCESS_INIT;
  51         struct strbuf out = STRBUF_INIT;
  52         int ret, env = git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1);
  53
  54         if (env != -1)
  55                 return env;
  56
  57         argv_array_pushl(&cp.args,
  58                          "config", "--bool", "rebase.usebuiltin", NULL);
  59         cp.git_cmd = 1;
  60         if (capture_command(&cp, &out, 6)) {
  61                 strbuf_release(&out);
  62                 return 1;
  63         }
  64
  65         strbuf_trim(&out);
  66         ret = !strcmp("true", out.buf);
  67         strbuf_release(&out);
  68         return ret;
  69 }
  70
  71 struct rebase_options {
  72         enum rebase_type type;
  73         const char *state_dir;
  74         struct commit *upstream;
  75         const char *upstream_name;
  76         const char *upstream_arg;
  77         char *head_name;
  78         struct object_id orig_head;
  79         struct commit *onto;
  80         const char *onto_name;
  81         const char *revisions;
  82         const char *switch_to;
  83         int root;
  84         struct object_id *squash_onto;
  85         struct commit *restrict_revision;
  86         int dont_finish_rebase;
  87         enum {
  88                 REBASE_NO_QUIET = 1<<0,
  89                 REBASE_VERBOSE = 1<<1,
  90                 REBASE_DIFFSTAT = 1<<2,
  91                 REBASE_FORCE = 1<<3,
  92                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  93         } flags;
  94         struct argv_array git_am_opts;
  95         const char *action;
  96         int signoff;
  97         int allow_rerere_autoupdate;
  98         int keep_empty;
  99         int autosquash;
 100         char *gpg_sign_opt;
 101         int autostash;
 102         char *cmd;
 103         int allow_empty_message;
 104         int rebase_merges, rebase_cousins;
 105         char *strategy, *strategy_opts;
 106         struct strbuf git_format_patch_opt;
 107 };
 108
 109 static int is_interactive(struct rebase_options *opts)
 110 {
 111         return opts->type == REBASE_INTERACTIVE ||
 112                 opts->type == REBASE_PRESERVE_MERGES;
 113 }
 114
 115 static void imply_interactive(struct rebase_options *opts, const char *option)
 116 {
 117         switch (opts->type) {
 118         case REBASE_AM:
 119                 die(_("%s requires an interactive rebase"), option);
 120                 break;
 121         case REBASE_INTERACTIVE:
 122         case REBASE_PRESERVE_MERGES:
 123                 break;
 124         case REBASE_MERGE:
 125                 /* we now implement --merge via --interactive */
 126         default:
 127                 opts->type = REBASE_INTERACTIVE; /* implied */
 128                 break;
 129         }
 130 }
 131
 132 /* Returns the filename prefixed by the state_dir */
 133 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 134 {
 135         static struct strbuf path = STRBUF_INIT;
 136         static size_t prefix_len;
 137
 138         if (!prefix_len) {
 139                 strbuf_addf(&path, "%s/", opts->state_dir);
 140                 prefix_len = path.len;
 141         }
 142
 143         strbuf_setlen(&path, prefix_len);
 144         strbuf_addstr(&path, filename);
 145         return path.buf;
 146 }
 147
 148 /* Read one file, then strip line endings */
 149 static int read_one(const char *path, struct strbuf *buf)
 150 {
 151         if (strbuf_read_file(buf, path, 0) < 0)
 152                 return error_errno(_("could not read '%s'"), path);
 153         strbuf_trim_trailing_newline(buf);
 154         return 0;
 155 }
 156
 157 /* Initialize the rebase options from the state directory. */
 158 static int read_basic_state(struct rebase_options *opts)
 159 {
 160         struct strbuf head_name = STRBUF_INIT;
 161         struct strbuf buf = STRBUF_INIT;
 162         struct object_id oid;
 163
 164         if (read_one(state_dir_path("head-name", opts), &head_name) ||
 165             read_one(state_dir_path("onto", opts), &buf))
 166                 return -1;
 167         opts->head_name = starts_with(head_name.buf, "refs/") ?
 168                 xstrdup(head_name.buf) : NULL;
 169         strbuf_release(&head_name);
 170         if (get_oid(buf.buf, &oid))
 171                 return error(_("could not get 'onto': '%s'"), buf.buf);
 172         opts->onto = lookup_commit_or_die(&oid, buf.buf);
 173
 174         /*
 175          * We always write to orig-head, but interactive rebase used to write to
 176          * head. Fall back to reading from head to cover for the case that the
 177          * user upgraded git with an ongoing interactive rebase.
 178          */
 179         strbuf_reset(&buf);
 180         if (file_exists(state_dir_path("orig-head", opts))) {
 181                 if (read_one(state_dir_path("orig-head", opts), &buf))
 182                         return -1;
 183         } else if (read_one(state_dir_path("head", opts), &buf))
 184                 return -1;
 185         if (get_oid(buf.buf, &opts->orig_head))
 186                 return error(_("invalid orig-head: '%s'"), buf.buf);
 187
 188         if (file_exists(state_dir_path("quiet", opts)))
 189                 opts->flags &= ~REBASE_NO_QUIET;
 190         else
 191                 opts->flags |= REBASE_NO_QUIET;
 192
 193         if (file_exists(state_dir_path("verbose", opts)))
 194                 opts->flags |= REBASE_VERBOSE;
 195
 196         if (file_exists(state_dir_path("signoff", opts))) {
 197                 opts->signoff = 1;
 198                 opts->flags |= REBASE_FORCE;
 199         }
 200
 201         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 202                 strbuf_reset(&buf);
 203                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 204                             &buf))
 205                         return -1;
 206                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
 207                         opts->allow_rerere_autoupdate = 1;
 208                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 209                         opts->allow_rerere_autoupdate = 0;
 210                 else
 211                         warning(_("ignoring invalid allow_rerere_autoupdate: "
 212                                   "'%s'"), buf.buf);
 213         } else
 214                 opts->allow_rerere_autoupdate = -1;
 215
 216         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 217                 strbuf_reset(&buf);
 218                 if (read_one(state_dir_path("gpg_sign_opt", opts),
 219                             &buf))
 220                         return -1;
 221                 free(opts->gpg_sign_opt);
 222                 opts->gpg_sign_opt = xstrdup(buf.buf);
 223         }
 224
 225         if (file_exists(state_dir_path("strategy", opts))) {
 226                 strbuf_reset(&buf);
 227                 if (read_one(state_dir_path("strategy", opts), &buf))
 228                         return -1;
 229                 free(opts->strategy);
 230                 opts->strategy = xstrdup(buf.buf);
 231         }
 232
 233         if (file_exists(state_dir_path("strategy_opts", opts))) {
 234                 strbuf_reset(&buf);
 235                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
 236                         return -1;
 237                 free(opts->strategy_opts);
 238                 opts->strategy_opts = xstrdup(buf.buf);
 239         }
 240
 241         strbuf_release(&buf);
 242
 243         return 0;
 244 }
 245
 246 static int apply_autostash(struct rebase_options *opts)
 247 {
 248         const char *path = state_dir_path("autostash", opts);
 249         struct strbuf autostash = STRBUF_INIT;
 250         struct child_process stash_apply = CHILD_PROCESS_INIT;
 251
 252         if (!file_exists(path))
 253                 return 0;
 254
 255         if (read_one(path, &autostash))
 256                 return error(_("Could not read '%s'"), path);
 257         /* Ensure that the hash is not mistaken for a number */
 258         strbuf_addstr(&autostash, "^0");
 259         argv_array_pushl(&stash_apply.args,
 260                          "stash", "apply", autostash.buf, NULL);
 261         stash_apply.git_cmd = 1;
 262         stash_apply.no_stderr = stash_apply.no_stdout =
 263                 stash_apply.no_stdin = 1;
 264         if (!run_command(&stash_apply))
 265                 printf(_("Applied autostash.\n"));
 266         else {
 267                 struct argv_array args = ARGV_ARRAY_INIT;
 268                 int res = 0;
 269
 270                 argv_array_pushl(&args,
 271                                  "stash", "store", "-m", "autostash", "-q",
 272                                  autostash.buf, NULL);
 273                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 274                         res = error(_("Cannot store %s"), autostash.buf);
 275                 argv_array_clear(&args);
 276                 strbuf_release(&autostash);
 277                 if (res)
 278                         return res;
 279
 280                 fprintf(stderr,
 281                         _("Applying autostash resulted in conflicts.\n"
 282                           "Your changes are safe in the stash.\n"
 283                           "You can run \"git stash pop\" or \"git stash drop\" "
 284                           "at any time.\n"));
 285         }
 286
 287         strbuf_release(&autostash);
 288         return 0;
 289 }
 290
 291 static int finish_rebase(struct rebase_options *opts)
 292 {
 293         struct strbuf dir = STRBUF_INIT;
 294         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 295
 296         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 297         apply_autostash(opts);
 298         close_all_packs(the_repository->objects);
 299         /*
 300          * We ignore errors in 'gc --auto', since the
 301          * user should see them.
 302          */
 303         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 304         strbuf_addstr(&dir, opts->state_dir);
 305         remove_dir_recursively(&dir, 0);
 306         strbuf_release(&dir);
 307
 308         return 0;
 309 }
 310
 311 static struct commit *peel_committish(const char *name)
 312 {
 313         struct object *obj;
 314         struct object_id oid;
 315
 316         if (get_oid(name, &oid))
 317                 return NULL;
 318         obj = parse_object(the_repository, &oid);
 319         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 320 }
 321
 322 static void add_var(struct strbuf *buf, const char *name, const char *value)
 323 {
 324         if (!value)
 325                 strbuf_addf(buf, "unset %s; ", name);
 326         else {
 327                 strbuf_addf(buf, "%s=", name);
 328                 sq_quote_buf(buf, value);
 329                 strbuf_addstr(buf, "; ");
 330         }
 331 }
 332
 333 static const char *resolvemsg =
 334 N_("Resolve all conflicts manually, mark them as resolved with\n"
 335 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 336 "You can instead skip this commit: run \"git rebase --skip\".\n"
 337 "To abort and get back to the state before \"git rebase\", run "
 338 "\"git rebase --abort\".");
 339
 340 static int run_specific_rebase(struct rebase_options *opts)
 341 {
 342         const char *argv[] = { NULL, NULL };
 343         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
 344         int status;
 345         const char *backend, *backend_func;
 346
 347         if (opts->type == REBASE_INTERACTIVE) {
 348                 /* Run builtin interactive rebase */
 349                 struct child_process child = CHILD_PROCESS_INIT;
 350
 351                 argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 352                                  resolvemsg);
 353                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 354                         argv_array_push(&child.env_array, "GIT_EDITOR=:");
 355                         opts->autosquash = 0;
 356                 }
 357
 358                 child.git_cmd = 1;
 359                 argv_array_push(&child.args, "rebase--interactive");
 360
 361                 if (opts->action)
 362                         argv_array_pushf(&child.args, "--%s", opts->action);
 363                 if (opts->keep_empty)
 364                         argv_array_push(&child.args, "--keep-empty");
 365                 if (opts->rebase_merges)
 366                         argv_array_push(&child.args, "--rebase-merges");
 367                 if (opts->rebase_cousins)
 368                         argv_array_push(&child.args, "--rebase-cousins");
 369                 if (opts->autosquash)
 370                         argv_array_push(&child.args, "--autosquash");
 371                 if (opts->flags & REBASE_VERBOSE)
 372                         argv_array_push(&child.args, "--verbose");
 373                 if (opts->flags & REBASE_FORCE)
 374                         argv_array_push(&child.args, "--no-ff");
 375                 if (opts->restrict_revision)
 376                         argv_array_pushf(&child.args,
 377                                          "--restrict-revision=^%s",
 378                                          oid_to_hex(&opts->restrict_revision->object.oid));
 379                 if (opts->upstream)
 380                         argv_array_pushf(&child.args, "--upstream=%s",
 381                                          oid_to_hex(&opts->upstream->object.oid));
 382                 if (opts->onto)
 383                         argv_array_pushf(&child.args, "--onto=%s",
 384                                          oid_to_hex(&opts->onto->object.oid));
 385                 if (opts->squash_onto)
 386                         argv_array_pushf(&child.args, "--squash-onto=%s",
 387                                          oid_to_hex(opts->squash_onto));
 388                 if (opts->onto_name)
 389                         argv_array_pushf(&child.args, "--onto-name=%s",
 390                                          opts->onto_name);
 391                 argv_array_pushf(&child.args, "--head-name=%s",
 392                                  opts->head_name ?
 393                                  opts->head_name : "detached HEAD");
 394                 if (opts->strategy)
 395                         argv_array_pushf(&child.args, "--strategy=%s",
 396                                          opts->strategy);
 397                 if (opts->strategy_opts)
 398                         argv_array_pushf(&child.args, "--strategy-opts=%s",
 399                                          opts->strategy_opts);
 400                 if (opts->switch_to)
 401                         argv_array_pushf(&child.args, "--switch-to=%s",
 402                                          opts->switch_to);
 403                 if (opts->cmd)
 404                         argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
 405                 if (opts->allow_empty_message)
 406                         argv_array_push(&child.args, "--allow-empty-message");
 407                 if (opts->allow_rerere_autoupdate > 0)
 408                         argv_array_push(&child.args, "--rerere-autoupdate");
 409                 else if (opts->allow_rerere_autoupdate == 0)
 410                         argv_array_push(&child.args, "--no-rerere-autoupdate");
 411                 if (opts->gpg_sign_opt)
 412                         argv_array_push(&child.args, opts->gpg_sign_opt);
 413                 if (opts->signoff)
 414                         argv_array_push(&child.args, "--signoff");
 415
 416                 status = run_command(&child);
 417                 goto finished_rebase;
 418         }
 419
 420         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 421         add_var(&script_snippet, "state_dir", opts->state_dir);
 422
 423         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 424         add_var(&script_snippet, "upstream", opts->upstream ?
 425                 oid_to_hex(&opts->upstream->object.oid) : NULL);
 426         add_var(&script_snippet, "head_name",
 427                 opts->head_name ? opts->head_name : "detached HEAD");
 428         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 429         add_var(&script_snippet, "onto", opts->onto ?
 430                 oid_to_hex(&opts->onto->object.oid) : NULL);
 431         add_var(&script_snippet, "onto_name", opts->onto_name);
 432         add_var(&script_snippet, "revisions", opts->revisions);
 433         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 434                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 435         add_var(&script_snippet, "GIT_QUIET",
 436                 opts->flags & REBASE_NO_QUIET ? "" : "t");
 437         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
 438         add_var(&script_snippet, "git_am_opt", buf.buf);
 439         strbuf_release(&buf);
 440         add_var(&script_snippet, "verbose",
 441                 opts->flags & REBASE_VERBOSE ? "t" : "");
 442         add_var(&script_snippet, "diffstat",
 443                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
 444         add_var(&script_snippet, "force_rebase",
 445                 opts->flags & REBASE_FORCE ? "t" : "");
 446         if (opts->switch_to)
 447                 add_var(&script_snippet, "switch_to", opts->switch_to);
 448         add_var(&script_snippet, "action", opts->action ? opts->action : "");
 449         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 450         add_var(&script_snippet, "allow_rerere_autoupdate",
 451                 opts->allow_rerere_autoupdate < 0 ? "" :
 452                 opts->allow_rerere_autoupdate ?
 453                 "--rerere-autoupdate" : "--no-rerere-autoupdate");
 454         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 455         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 456         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 457         add_var(&script_snippet, "cmd", opts->cmd);
 458         add_var(&script_snippet, "allow_empty_message",
 459                 opts->allow_empty_message ?  "--allow-empty-message" : "");
 460         add_var(&script_snippet, "rebase_merges",
 461                 opts->rebase_merges ? "t" : "");
 462         add_var(&script_snippet, "rebase_cousins",
 463                 opts->rebase_cousins ? "t" : "");
 464         add_var(&script_snippet, "strategy", opts->strategy);
 465         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 466         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 467         add_var(&script_snippet, "squash_onto",
 468                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 469         add_var(&script_snippet, "git_format_patch_opt",
 470                 opts->git_format_patch_opt.buf);
 471
 472         if (is_interactive(opts) &&
 473             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 474                 strbuf_addstr(&script_snippet,
 475                               "GIT_EDITOR=:; export GIT_EDITOR; ");
 476                 opts->autosquash = 0;
 477         }
 478
 479         switch (opts->type) {
 480         case REBASE_AM:
 481                 backend = "git-rebase--am";
 482                 backend_func = "git_rebase__am";
 483                 break;
 484         case REBASE_PRESERVE_MERGES:
 485                 backend = "git-rebase--preserve-merges";
 486                 backend_func = "git_rebase__preserve_merges";
 487                 break;
 488         default:
 489                 BUG("Unhandled rebase type %d", opts->type);
 490                 break;
 491         }
 492
 493         strbuf_addf(&script_snippet,
 494                     ". git-sh-setup && . git-rebase--common &&"
 495                     " . %s && %s", backend, backend_func);
 496         argv[0] = script_snippet.buf;
 497
 498         status = run_command_v_opt(argv, RUN_USING_SHELL);
 499 finished_rebase:
 500         if (opts->dont_finish_rebase)
 501                 ; /* do nothing */
 502         else if (opts->type == REBASE_INTERACTIVE)
 503                 ; /* interactive rebase cleans up after itself */
 504         else if (status == 0) {
 505                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 506                         finish_rebase(opts);
 507         } else if (status == 2) {
 508                 struct strbuf dir = STRBUF_INIT;
 509
 510                 apply_autostash(opts);
 511                 strbuf_addstr(&dir, opts->state_dir);
 512                 remove_dir_recursively(&dir, 0);
 513                 strbuf_release(&dir);
 514                 die("Nothing to do");
 515         }
 516
 517         strbuf_release(&script_snippet);
 518
 519         return status ? -1 : 0;
 520 }
 521
 522 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 523
 524 #define RESET_HEAD_DETACH (1<<0)
 525 #define RESET_HEAD_HARD (1<<1)
 526
 527 static int reset_head(struct object_id *oid, const char *action,
 528                       const char *switch_to_branch, unsigned flags,
 529                       const char *reflog_orig_head, const char *reflog_head)
 530 {
 531         unsigned detach_head = flags & RESET_HEAD_DETACH;
 532         unsigned reset_hard = flags & RESET_HEAD_HARD;
 533         struct object_id head_oid;
 534         struct tree_desc desc[2] = { { NULL }, { NULL } };
 535         struct lock_file lock = LOCK_INIT;
 536         struct unpack_trees_options unpack_tree_opts;
 537         struct tree *tree;
 538         const char *reflog_action;
 539         struct strbuf msg = STRBUF_INIT;
 540         size_t prefix_len;
 541         struct object_id *orig = NULL, oid_orig,
 542                 *old_orig = NULL, oid_old_orig;
 543         int ret = 0, nr = 0;
 544
 545         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 546                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 547
 548         if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 549                 ret = -1;
 550                 goto leave_reset_head;
 551         }
 552
 553         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 554                 ret = error(_("could not determine HEAD revision"));
 555                 goto leave_reset_head;
 556         }
 557
 558         if (!oid)
 559                 oid = &head_oid;
 560
 561         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 562         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 563         unpack_tree_opts.head_idx = 1;
 564         unpack_tree_opts.src_index = the_repository->index;
 565         unpack_tree_opts.dst_index = the_repository->index;
 566         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 567         unpack_tree_opts.update = 1;
 568         unpack_tree_opts.merge = 1;
 569         if (!detach_head)
 570                 unpack_tree_opts.reset = 1;
 571
 572         if (read_index_unmerged(the_repository->index) < 0) {
 573                 ret = error(_("could not read index"));
 574                 goto leave_reset_head;
 575         }
 576
 577         if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
 578                 ret = error(_("failed to find tree of %s"),
 579                             oid_to_hex(&head_oid));
 580                 goto leave_reset_head;
 581         }
 582
 583         if (!fill_tree_descriptor(&desc[nr++], oid)) {
 584                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 585                 goto leave_reset_head;
 586         }
 587
 588         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 589                 ret = -1;
 590                 goto leave_reset_head;
 591         }
 592
 593         tree = parse_tree_indirect(oid);
 594         prime_cache_tree(the_repository->index, tree);
 595
 596         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 597                 ret = error(_("could not write index"));
 598                 goto leave_reset_head;
 599         }
 600
 601         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 602         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 603         prefix_len = msg.len;
 604
 605         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 606                 old_orig = &oid_old_orig;
 607         if (!get_oid("HEAD", &oid_orig)) {
 608                 orig = &oid_orig;
 609                 if (!reflog_orig_head) {
 610                         strbuf_addstr(&msg, "updating ORIG_HEAD");
 611                         reflog_orig_head = msg.buf;
 612                 }
 613                 update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
 614                            UPDATE_REFS_MSG_ON_ERR);
 615         } else if (old_orig)
 616                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 617         if (!reflog_head) {
 618                 strbuf_setlen(&msg, prefix_len);
 619                 strbuf_addstr(&msg, "updating HEAD");
 620                 reflog_head = msg.buf;
 621         }
 622         if (!switch_to_branch)
 623                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 624                                  detach_head ? REF_NO_DEREF : 0,
 625                                  UPDATE_REFS_MSG_ON_ERR);
 626         else {
 627                 ret = create_symref("HEAD", switch_to_branch, msg.buf);
 628                 if (!ret)
 629                         ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 630                                          UPDATE_REFS_MSG_ON_ERR);
 631         }
 632
 633 leave_reset_head:
 634         strbuf_release(&msg);
 635         rollback_lock_file(&lock);
 636         while (nr)
 637                 free((void *)desc[--nr].buffer);
 638         return ret;
 639 }
 640
 641 static int rebase_config(const char *var, const char *value, void *data)
 642 {
 643         struct rebase_options *opts = data;
 644
 645         if (!strcmp(var, "rebase.stat")) {
 646                 if (git_config_bool(var, value))
 647                         opts->flags |= REBASE_DIFFSTAT;
 648                 else
 649                         opts->flags &= !REBASE_DIFFSTAT;
 650                 return 0;
 651         }
 652
 653         if (!strcmp(var, "rebase.autosquash")) {
 654                 opts->autosquash = git_config_bool(var, value);
 655                 return 0;
 656         }
 657
 658         if (!strcmp(var, "commit.gpgsign")) {
 659                 free(opts->gpg_sign_opt);
 660                 opts->gpg_sign_opt = git_config_bool(var, value) ?
 661                         xstrdup("-S") : NULL;
 662                 return 0;
 663         }
 664
 665         if (!strcmp(var, "rebase.autostash")) {
 666                 opts->autostash = git_config_bool(var, value);
 667                 return 0;
 668         }
 669
 670         return git_default_config(var, value, data);
 671 }
 672
 673 /*
 674  * Determines whether the commits in from..to are linear, i.e. contain
 675  * no merge commits. This function *expects* `from` to be an ancestor of
 676  * `to`.
 677  */
 678 static int is_linear_history(struct commit *from, struct commit *to)
 679 {
 680         while (to && to != from) {
 681                 parse_commit(to);
 682                 if (!to->parents)
 683                         return 1;
 684                 if (to->parents->next)
 685                         return 0;
 686                 to = to->parents->item;
 687         }
 688         return 1;
 689 }
 690
 691 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 692                             struct object_id *merge_base)
 693 {
 694         struct commit *head = lookup_commit(the_repository, head_oid);
 695         struct commit_list *merge_bases;
 696         int res;
 697
 698         if (!head)
 699                 return 0;
 700
 701         merge_bases = get_merge_bases(onto, head);
 702         if (merge_bases && !merge_bases->next) {
 703                 oidcpy(merge_base, &merge_bases->item->object.oid);
 704                 res = oideq(merge_base, &onto->object.oid);
 705         } else {
 706                 oidcpy(merge_base, &null_oid);
 707                 res = 0;
 708         }
 709         free_commit_list(merge_bases);
 710         return res && is_linear_history(onto, head);
 711 }
 712
 713 /* -i followed by -m is still -i */
 714 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 715 {
 716         struct rebase_options *opts = opt->value;
 717
 718         BUG_ON_OPT_NEG(unset);
 719         BUG_ON_OPT_ARG(arg);
 720
 721         if (!is_interactive(opts))
 722                 opts->type = REBASE_MERGE;
 723
 724         return 0;
 725 }
 726
 727 /* -i followed by -p is still explicitly interactive, but -p alone is not */
 728 static int parse_opt_interactive(const struct option *opt, const char *arg,
 729                                  int unset)
 730 {
 731         struct rebase_options *opts = opt->value;
 732
 733         BUG_ON_OPT_NEG(unset);
 734         BUG_ON_OPT_ARG(arg);
 735
 736         opts->type = REBASE_INTERACTIVE;
 737         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 738
 739         return 0;
 740 }
 741
 742 static void NORETURN error_on_missing_default_upstream(void)
 743 {
 744         struct branch *current_branch = branch_get(NULL);
 745
 746         printf(_("%s\n"
 747                  "Please specify which branch you want to rebase against.\n"
 748                  "See git-rebase(1) for details.\n"
 749                  "\n"
 750                  "    git rebase '<branch>'\n"
 751                  "\n"),
 752                 current_branch ? _("There is no tracking information for "
 753                         "the current branch.") :
 754                         _("You are not currently on a branch."));
 755
 756         if (current_branch) {
 757                 const char *remote = current_branch->remote_name;
 758
 759                 if (!remote)
 760                         remote = _("<remote>");
 761
 762                 printf(_("If you wish to set tracking information for this "
 763                          "branch you can do so with:\n"
 764                          "\n"
 765                          "    git branch --set-upstream-to=%s/<branch> %s\n"
 766                          "\n"),
 767                        remote, current_branch->name);
 768         }
 769         exit(1);
 770 }
 771
 772 static void set_reflog_action(struct rebase_options *options)
 773 {
 774         const char *env;
 775         struct strbuf buf = STRBUF_INIT;
 776
 777         if (!is_interactive(options))
 778                 return;
 779
 780         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 781         if (env && strcmp("rebase", env))
 782                 return; /* only override it if it is "rebase" */
 783
 784         strbuf_addf(&buf, "rebase -i (%s)", options->action);
 785         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
 786         strbuf_release(&buf);
 787 }
 788
 789 int cmd_rebase(int argc, const char **argv, const char *prefix)
 790 {
 791         struct rebase_options options = {
 792                 .type = REBASE_UNSPECIFIED,
 793                 .flags = REBASE_NO_QUIET,
 794                 .git_am_opts = ARGV_ARRAY_INIT,
 795                 .allow_rerere_autoupdate  = -1,
 796                 .allow_empty_message = 1,
 797                 .git_format_patch_opt = STRBUF_INIT,
 798         };
 799         const char *branch_name;
 800         int ret, flags, total_argc, in_progress = 0;
 801         int ok_to_skip_pre_rebase = 0;
 802         struct strbuf msg = STRBUF_INIT;
 803         struct strbuf revisions = STRBUF_INIT;
 804         struct strbuf buf = STRBUF_INIT;
 805         struct object_id merge_base;
 806         enum {
 807                 NO_ACTION,
 808                 ACTION_CONTINUE,
 809                 ACTION_SKIP,
 810                 ACTION_ABORT,
 811                 ACTION_QUIT,
 812                 ACTION_EDIT_TODO,
 813                 ACTION_SHOW_CURRENT_PATCH,
 814         } action = NO_ACTION;
 815         const char *gpg_sign = NULL;
 816         struct string_list exec = STRING_LIST_INIT_NODUP;
 817         const char *rebase_merges = NULL;
 818         int fork_point = -1;
 819         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 820         struct object_id squash_onto;
 821         char *squash_onto_name = NULL;
 822         struct option builtin_rebase_options[] = {
 823                 OPT_STRING(0, "onto", &options.onto_name,
 824                            N_("revision"),
 825                            N_("rebase onto given branch instead of upstream")),
 826                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 827                          N_("allow pre-rebase hook to run")),
 828                 OPT_NEGBIT('q', "quiet", &options.flags,
 829                            N_("be quiet. implies --no-stat"),
 830                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 831                 OPT_BIT('v', "verbose", &options.flags,
 832                         N_("display a diffstat of what changed upstream"),
 833                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 834                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 835                         N_("do not show diffstat of what changed upstream"),
 836                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 837                 OPT_BOOL(0, "signoff", &options.signoff,
 838                          N_("add a Signed-off-by: line to each commit")),
 839                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
 840                                   NULL, N_("passed to 'git am'"),
 841                                   PARSE_OPT_NOARG),
 842                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 843                                   &options.git_am_opts, NULL,
 844                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
 845                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
 846                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
 847                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 848                                   N_("passed to 'git apply'"), 0),
 849                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
 850                                   N_("action"), N_("passed to 'git apply'"), 0),
 851                 OPT_BIT('f', "force-rebase", &options.flags,
 852                         N_("cherry-pick all commits, even if unchanged"),
 853                         REBASE_FORCE),
 854                 OPT_BIT(0, "no-ff", &options.flags,
 855                         N_("cherry-pick all commits, even if unchanged"),
 856                         REBASE_FORCE),
 857                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
 858                             ACTION_CONTINUE),
 859                 OPT_CMDMODE(0, "skip", &action,
 860                             N_("skip current patch and continue"), ACTION_SKIP),
 861                 OPT_CMDMODE(0, "abort", &action,
 862                             N_("abort and check out the original branch"),
 863                             ACTION_ABORT),
 864                 OPT_CMDMODE(0, "quit", &action,
 865                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
 866                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 867                             "during an interactive rebase"), ACTION_EDIT_TODO),
 868                 OPT_CMDMODE(0, "show-current-patch", &action,
 869                             N_("show the patch file being applied or merged"),
 870                             ACTION_SHOW_CURRENT_PATCH),
 871                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 872                         N_("use merging strategies to rebase"),
 873                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 874                         parse_opt_merge },
 875                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 876                         N_("let the user edit the list of commits to rebase"),
 877                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 878                         parse_opt_interactive },
 879                 OPT_SET_INT('p', "preserve-merges", &options.type,
 880                             N_("try to recreate merges instead of ignoring "
 881                                "them"), REBASE_PRESERVE_MERGES),
 882                 OPT_BOOL(0, "rerere-autoupdate",
 883                          &options.allow_rerere_autoupdate,
 884                          N_("allow rerere to update index with resolved "
 885                             "conflict")),
 886                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
 887                          N_("preserve empty commits during rebase")),
 888                 OPT_BOOL(0, "autosquash", &options.autosquash,
 889                          N_("move commits that begin with "
 890                             "squash!/fixup! under -i")),
 891                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 892                         N_("GPG-sign commits"),
 893                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 894                 OPT_BOOL(0, "autostash", &options.autostash,
 895                          N_("automatically stash/stash pop before and after")),
 896                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 897                                 N_("add exec lines after each commit of the "
 898                                    "editable list")),
 899                 OPT_BOOL(0, "allow-empty-message",
 900                          &options.allow_empty_message,
 901                          N_("allow rebasing commits with empty messages")),
 902                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 903                         N_("mode"),
 904                         N_("try to rebase merges instead of skipping them"),
 905                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 906                 OPT_BOOL(0, "fork-point", &fork_point,
 907                          N_("use 'merge-base --fork-point' to refine upstream")),
 908                 OPT_STRING('s', "strategy", &options.strategy,
 909                            N_("strategy"), N_("use the given merge strategy")),
 910                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 911                                 N_("option"),
 912                                 N_("pass the argument through to the merge "
 913                                    "strategy")),
 914                 OPT_BOOL(0, "root", &options.root,
 915                          N_("rebase all reachable commits up to the root(s)")),
 916                 OPT_END(),
 917         };
 918         int i;
 919
 920         /*
 921          * NEEDSWORK: Once the builtin rebase has been tested enough
 922          * and git-legacy-rebase.sh is retired to contrib/, this preamble
 923          * can be removed.
 924          */
 925
 926         if (!use_builtin_rebase()) {
 927                 const char *path = mkpath("%s/git-legacy-rebase",
 928                                           git_exec_path());
 929
 930                 if (sane_execvp(path, (char **)argv) < 0)
 931                         die_errno(_("could not exec %s"), path);
 932                 else
 933                         BUG("sane_execvp() returned???");
 934         }
 935
 936         if (argc == 2 && !strcmp(argv[1], "-h"))
 937                 usage_with_options(builtin_rebase_usage,
 938                                    builtin_rebase_options);
 939
 940         prefix = setup_git_directory();
 941         trace_repo_setup(prefix);
 942         setup_work_tree();
 943
 944         git_config(rebase_config, &options);
 945
 946         strbuf_reset(&buf);
 947         strbuf_addf(&buf, "%s/applying", apply_dir());
 948         if(file_exists(buf.buf))
 949                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
 950
 951         if (is_directory(apply_dir())) {
 952                 options.type = REBASE_AM;
 953                 options.state_dir = apply_dir();
 954         } else if (is_directory(merge_dir())) {
 955                 strbuf_reset(&buf);
 956                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
 957                 if (is_directory(buf.buf)) {
 958                         options.type = REBASE_PRESERVE_MERGES;
 959                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 960                 } else {
 961                         strbuf_reset(&buf);
 962                         strbuf_addf(&buf, "%s/interactive", merge_dir());
 963                         if(file_exists(buf.buf)) {
 964                                 options.type = REBASE_INTERACTIVE;
 965                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 966                         } else
 967                                 options.type = REBASE_MERGE;
 968                 }
 969                 options.state_dir = merge_dir();
 970         }
 971
 972         if (options.type != REBASE_UNSPECIFIED)
 973                 in_progress = 1;
 974
 975         total_argc = argc;
 976         argc = parse_options(argc, argv, prefix,
 977                              builtin_rebase_options,
 978                              builtin_rebase_usage, 0);
 979
 980         if (action != NO_ACTION && total_argc != 2) {
 981                 usage_with_options(builtin_rebase_usage,
 982                                    builtin_rebase_options);
 983         }
 984
 985         if (argc > 2)
 986                 usage_with_options(builtin_rebase_usage,
 987                                    builtin_rebase_options);
 988
 989         if (action != NO_ACTION && !in_progress)
 990                 die(_("No rebase in progress?"));
 991         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
 992
 993         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 994                 die(_("The --edit-todo action can only be used during "
 995                       "interactive rebase."));
 996
 997         switch (action) {
 998         case ACTION_CONTINUE: {
 999                 struct object_id head;
1000                 struct lock_file lock_file = LOCK_INIT;
1001                 int fd;
1002
1003                 options.action = "continue";
1004                 set_reflog_action(&options);
1005
1006                 /* Sanity check */
1007                 if (get_oid("HEAD", &head))
1008                         die(_("Cannot read HEAD"));
1009
1010                 fd = hold_locked_index(&lock_file, 0);
1011                 if (read_index(the_repository->index) < 0)
1012                         die(_("could not read index"));
1013                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1014                               NULL);
1015                 if (0 <= fd)
1016                         update_index_if_able(the_repository->index,
1017                                              &lock_file);
1018                 rollback_lock_file(&lock_file);
1019
1020                 if (has_unstaged_changes(1)) {
1021                         puts(_("You must edit all merge conflicts and then\n"
1022                                "mark them as resolved using git add"));
1023                         exit(1);
1024                 }
1025                 if (read_basic_state(&options))
1026                         exit(1);
1027                 goto run_rebase;
1028         }
1029         case ACTION_SKIP: {
1030                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1031
1032                 options.action = "skip";
1033                 set_reflog_action(&options);
1034
1035                 rerere_clear(&merge_rr);
1036                 string_list_clear(&merge_rr, 1);
1037
1038                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1039                                NULL, NULL) < 0)
1040                         die(_("could not discard worktree changes"));
1041                 remove_branch_state();
1042                 if (read_basic_state(&options))
1043                         exit(1);
1044                 goto run_rebase;
1045         }
1046         case ACTION_ABORT: {
1047                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1048                 options.action = "abort";
1049                 set_reflog_action(&options);
1050
1051                 rerere_clear(&merge_rr);
1052                 string_list_clear(&merge_rr, 1);
1053
1054                 if (read_basic_state(&options))
1055                         exit(1);
1056                 if (reset_head(&options.orig_head, "reset",
1057                                options.head_name, RESET_HEAD_HARD,
1058                                NULL, NULL) < 0)
1059                         die(_("could not move back to %s"),
1060                             oid_to_hex(&options.orig_head));
1061                 remove_branch_state();
1062                 ret = finish_rebase(&options);
1063                 goto cleanup;
1064         }
1065         case ACTION_QUIT: {
1066                 strbuf_reset(&buf);
1067                 strbuf_addstr(&buf, options.state_dir);
1068                 ret = !!remove_dir_recursively(&buf, 0);
1069                 if (ret)
1070                         die(_("could not remove '%s'"), options.state_dir);
1071                 goto cleanup;
1072         }
1073         case ACTION_EDIT_TODO:
1074                 options.action = "edit-todo";
1075                 options.dont_finish_rebase = 1;
1076                 goto run_rebase;
1077         case ACTION_SHOW_CURRENT_PATCH:
1078                 options.action = "show-current-patch";
1079                 options.dont_finish_rebase = 1;
1080                 goto run_rebase;
1081         case NO_ACTION:
1082                 break;
1083         default:
1084                 BUG("action: %d", action);
1085         }
1086
1087         /* Make sure no rebase is in progress */
1088         if (in_progress) {
1089                 const char *last_slash = strrchr(options.state_dir, '/');
1090                 const char *state_dir_base =
1091                         last_slash ? last_slash + 1 : options.state_dir;
1092                 const char *cmd_live_rebase =
1093                         "git rebase (--continue | --abort | --skip)";
1094                 strbuf_reset(&buf);
1095                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1096                 die(_("It seems that there is already a %s directory, and\n"
1097                       "I wonder if you are in the middle of another rebase.  "
1098                       "If that is the\n"
1099                       "case, please try\n\t%s\n"
1100                       "If that is not the case, please\n\t%s\n"
1101                       "and run me again.  I am stopping in case you still "
1102                       "have something\n"
1103                       "valuable there.\n"),
1104                     state_dir_base, cmd_live_rebase, buf.buf);
1105         }
1106
1107         for (i = 0; i < options.git_am_opts.argc; i++) {
1108                 const char *option = options.git_am_opts.argv[i], *p;
1109                 if (!strcmp(option, "--committer-date-is-author-date") ||
1110                     !strcmp(option, "--ignore-date") ||
1111                     !strcmp(option, "--whitespace=fix") ||
1112                     !strcmp(option, "--whitespace=strip"))
1113                         options.flags |= REBASE_FORCE;
1114                 else if (skip_prefix(option, "-C", &p)) {
1115                         while (*p)
1116                                 if (!isdigit(*(p++)))
1117                                         die(_("switch `C' expects a "
1118                                               "numerical value"));
1119                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1120                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1121                             strcmp(p, "error") && strcmp(p, "error-all"))
1122                                 die("Invalid whitespace option: '%s'", p);
1123                 }
1124         }
1125
1126         if (!(options.flags & REBASE_NO_QUIET))
1127                 argv_array_push(&options.git_am_opts, "-q");
1128
1129         if (options.keep_empty)
1130                 imply_interactive(&options, "--keep-empty");
1131
1132         if (gpg_sign) {
1133                 free(options.gpg_sign_opt);
1134                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1135         }
1136
1137         if (exec.nr) {
1138                 int i;
1139
1140                 imply_interactive(&options, "--exec");
1141
1142                 strbuf_reset(&buf);
1143                 for (i = 0; i < exec.nr; i++)
1144                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1145                 options.cmd = xstrdup(buf.buf);
1146         }
1147
1148         if (rebase_merges) {
1149                 if (!*rebase_merges)
1150                         ; /* default mode; do nothing */
1151                 else if (!strcmp("rebase-cousins", rebase_merges))
1152                         options.rebase_cousins = 1;
1153                 else if (strcmp("no-rebase-cousins", rebase_merges))
1154                         die(_("Unknown mode: %s"), rebase_merges);
1155                 options.rebase_merges = 1;
1156                 imply_interactive(&options, "--rebase-merges");
1157         }
1158
1159         if (strategy_options.nr) {
1160                 int i;
1161
1162                 if (!options.strategy)
1163                         options.strategy = "recursive";
1164
1165                 strbuf_reset(&buf);
1166                 for (i = 0; i < strategy_options.nr; i++)
1167                         strbuf_addf(&buf, " --%s",
1168                                     strategy_options.items[i].string);
1169                 options.strategy_opts = xstrdup(buf.buf);
1170         }
1171
1172         if (options.strategy) {
1173                 options.strategy = xstrdup(options.strategy);
1174                 switch (options.type) {
1175                 case REBASE_AM:
1176                         die(_("--strategy requires --merge or --interactive"));
1177                 case REBASE_MERGE:
1178                 case REBASE_INTERACTIVE:
1179                 case REBASE_PRESERVE_MERGES:
1180                         /* compatible */
1181                         break;
1182                 case REBASE_UNSPECIFIED:
1183                         options.type = REBASE_MERGE;
1184                         break;
1185                 default:
1186                         BUG("unhandled rebase type (%d)", options.type);
1187                 }
1188         }
1189
1190         if (options.type == REBASE_MERGE)
1191                 imply_interactive(&options, "--merge");
1192
1193         if (options.root && !options.onto_name)
1194                 imply_interactive(&options, "--root without --onto");
1195
1196         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1197                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1198
1199         switch (options.type) {
1200         case REBASE_MERGE:
1201         case REBASE_INTERACTIVE:
1202         case REBASE_PRESERVE_MERGES:
1203                 options.state_dir = merge_dir();
1204                 break;
1205         case REBASE_AM:
1206                 options.state_dir = apply_dir();
1207                 break;
1208         default:
1209                 /* the default rebase backend is `--am` */
1210                 options.type = REBASE_AM;
1211                 options.state_dir = apply_dir();
1212                 break;
1213         }
1214
1215         if (options.git_am_opts.argc) {
1216                 /* all am options except -q are compatible only with --am */
1217                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1218                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1219                                 break;
1220
1221                 if (is_interactive(&options) && i >= 0)
1222                         die(_("cannot combine am options with either "
1223                               "interactive or merge options"));
1224         }
1225
1226         if (options.signoff) {
1227                 if (options.type == REBASE_PRESERVE_MERGES)
1228                         die("cannot combine '--signoff' with "
1229                             "'--preserve-merges'");
1230                 argv_array_push(&options.git_am_opts, "--signoff");
1231                 options.flags |= REBASE_FORCE;
1232         }
1233
1234         if (options.type == REBASE_PRESERVE_MERGES)
1235                 /*
1236                  * Note: incompatibility with --signoff handled in signoff block above
1237                  * Note: incompatibility with --interactive is just a strong warning;
1238                  *       git-rebase.txt caveats with "unless you know what you are doing"
1239                  */
1240                 if (options.rebase_merges)
1241                         die(_("cannot combine '--preserve-merges' with "
1242                               "'--rebase-merges'"));
1243
1244         if (options.rebase_merges) {
1245                 if (strategy_options.nr)
1246                         die(_("cannot combine '--rebase-merges' with "
1247                               "'--strategy-option'"));
1248                 if (options.strategy)
1249                         die(_("cannot combine '--rebase-merges' with "
1250                               "'--strategy'"));
1251         }
1252
1253         if (!options.root) {
1254                 if (argc < 1) {
1255                         struct branch *branch;
1256
1257                         branch = branch_get(NULL);
1258                         options.upstream_name = branch_get_upstream(branch,
1259                                                                     NULL);
1260                         if (!options.upstream_name)
1261                                 error_on_missing_default_upstream();
1262                         if (fork_point < 0)
1263                                 fork_point = 1;
1264                 } else {
1265                         options.upstream_name = argv[0];
1266                         argc--;
1267                         argv++;
1268                         if (!strcmp(options.upstream_name, "-"))
1269                                 options.upstream_name = "@{-1}";
1270                 }
1271                 options.upstream = peel_committish(options.upstream_name);
1272                 if (!options.upstream)
1273                         die(_("invalid upstream '%s'"), options.upstream_name);
1274                 options.upstream_arg = options.upstream_name;
1275         } else {
1276                 if (!options.onto_name) {
1277                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1278                                         &squash_onto, NULL, NULL) < 0)
1279                                 die(_("Could not create new root commit"));
1280                         options.squash_onto = &squash_onto;
1281                         options.onto_name = squash_onto_name =
1282                                 xstrdup(oid_to_hex(&squash_onto));
1283                 }
1284                 options.upstream_name = NULL;
1285                 options.upstream = NULL;
1286                 if (argc > 1)
1287                         usage_with_options(builtin_rebase_usage,
1288                                            builtin_rebase_options);
1289                 options.upstream_arg = "--root";
1290         }
1291
1292         /* Make sure the branch to rebase onto is valid. */
1293         if (!options.onto_name)
1294                 options.onto_name = options.upstream_name;
1295         if (strstr(options.onto_name, "...")) {
1296                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
1297                         die(_("'%s': need exactly one merge base"),
1298                             options.onto_name);
1299                 options.onto = lookup_commit_or_die(&merge_base,
1300                                                     options.onto_name);
1301         } else {
1302                 options.onto = peel_committish(options.onto_name);
1303                 if (!options.onto)
1304                         die(_("Does not point to a valid commit '%s'"),
1305                                 options.onto_name);
1306         }
1307
1308         /*
1309          * If the branch to rebase is given, that is the branch we will rebase
1310          * branch_name -- branch/commit being rebased, or
1311          *                HEAD (already detached)
1312          * orig_head -- commit object name of tip of the branch before rebasing
1313          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1314          */
1315         if (argc == 1) {
1316                 /* Is it "rebase other branchname" or "rebase other commit"? */
1317                 branch_name = argv[0];
1318                 options.switch_to = argv[0];
1319
1320                 /* Is it a local branch? */
1321                 strbuf_reset(&buf);
1322                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1323                 if (!read_ref(buf.buf, &options.orig_head))
1324                         options.head_name = xstrdup(buf.buf);
1325                 /* If not is it a valid ref (branch or commit)? */
1326                 else if (!get_oid(branch_name, &options.orig_head))
1327                         options.head_name = NULL;
1328                 else
1329                         die(_("fatal: no such branch/commit '%s'"),
1330                             branch_name);
1331         } else if (argc == 0) {
1332                 /* Do not need to switch branches, we are already on it. */
1333                 options.head_name =
1334                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1335                                          &flags));
1336                 if (!options.head_name)
1337                         die(_("No such ref: %s"), "HEAD");
1338                 if (flags & REF_ISSYMREF) {
1339                         if (!skip_prefix(options.head_name,
1340                                          "refs/heads/", &branch_name))
1341                                 branch_name = options.head_name;
1342
1343                 } else {
1344                         free(options.head_name);
1345                         options.head_name = NULL;
1346                         branch_name = "HEAD";
1347                 }
1348                 if (get_oid("HEAD", &options.orig_head))
1349                         die(_("Could not resolve HEAD to a revision"));
1350         } else
1351                 BUG("unexpected number of arguments left to parse");
1352
1353         if (fork_point > 0) {
1354                 struct commit *head =
1355                         lookup_commit_reference(the_repository,
1356                                                 &options.orig_head);
1357                 options.restrict_revision =
1358                         get_fork_point(options.upstream_name, head);
1359         }
1360
1361         if (read_index(the_repository->index) < 0)
1362                 die(_("could not read index"));
1363
1364         if (options.autostash) {
1365                 struct lock_file lock_file = LOCK_INIT;
1366                 int fd;
1367
1368                 fd = hold_locked_index(&lock_file, 0);
1369                 refresh_cache(REFRESH_QUIET);
1370                 if (0 <= fd)
1371                         update_index_if_able(&the_index, &lock_file);
1372                 rollback_lock_file(&lock_file);
1373
1374                 if (has_unstaged_changes(1) || has_uncommitted_changes(1)) {
1375                         const char *autostash =
1376                                 state_dir_path("autostash", &options);
1377                         struct child_process stash = CHILD_PROCESS_INIT;
1378                         struct object_id oid;
1379                         struct commit *head =
1380                                 lookup_commit_reference(the_repository,
1381                                                         &options.orig_head);
1382
1383                         argv_array_pushl(&stash.args,
1384                                          "stash", "create", "autostash", NULL);
1385                         stash.git_cmd = 1;
1386                         stash.no_stdin = 1;
1387                         strbuf_reset(&buf);
1388                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1389                                 die(_("Cannot autostash"));
1390                         strbuf_trim_trailing_newline(&buf);
1391                         if (get_oid(buf.buf, &oid))
1392                                 die(_("Unexpected stash response: '%s'"),
1393                                     buf.buf);
1394                         strbuf_reset(&buf);
1395                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1396
1397                         if (safe_create_leading_directories_const(autostash))
1398                                 die(_("Could not create directory for '%s'"),
1399                                     options.state_dir);
1400                         write_file(autostash, "%s", oid_to_hex(&oid));
1401                         printf(_("Created autostash: %s\n"), buf.buf);
1402                         if (reset_head(&head->object.oid, "reset --hard",
1403                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1404                                 die(_("could not reset --hard"));
1405                         printf(_("HEAD is now at %s"),
1406                                find_unique_abbrev(&head->object.oid,
1407                                                   DEFAULT_ABBREV));
1408                         strbuf_reset(&buf);
1409                         pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1410                         if (buf.len > 0)
1411                                 printf(" %s", buf.buf);
1412                         putchar('\n');
1413
1414                         if (discard_index(the_repository->index) < 0 ||
1415                                 read_index(the_repository->index) < 0)
1416                                 die(_("could not read index"));
1417                 }
1418         }
1419
1420         if (require_clean_work_tree("rebase",
1421                                     _("Please commit or stash them."), 1, 1)) {
1422                 ret = 1;
1423                 goto cleanup;
1424         }
1425
1426         /*
1427          * Now we are rebasing commits upstream..orig_head (or with --root,
1428          * everything leading up to orig_head) on top of onto.
1429          */
1430
1431         /*
1432          * Check if we are already based on onto with linear history,
1433          * but this should be done only when upstream and onto are the same
1434          * and if this is not an interactive rebase.
1435          */
1436         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1437             !is_interactive(&options) && !options.restrict_revision &&
1438             options.upstream &&
1439             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1440                 int flag;
1441
1442                 if (!(options.flags & REBASE_FORCE)) {
1443                         /* Lazily switch to the target branch if needed... */
1444                         if (options.switch_to) {
1445                                 struct object_id oid;
1446
1447                                 if (get_oid(options.switch_to, &oid) < 0) {
1448                                         ret = !!error(_("could not parse '%s'"),
1449                                                       options.switch_to);
1450                                         goto cleanup;
1451                                 }
1452
1453                                 strbuf_reset(&buf);
1454                                 strbuf_addf(&buf, "%s: checkout %s",
1455                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1456                                             options.switch_to);
1457                                 if (reset_head(&oid, "checkout",
1458                                                options.head_name, 0,
1459                                                NULL, buf.buf) < 0) {
1460                                         ret = !!error(_("could not switch to "
1461                                                         "%s"),
1462                                                       options.switch_to);
1463                                         goto cleanup;
1464                                 }
1465                         }
1466
1467                         if (!(options.flags & REBASE_NO_QUIET))
1468                                 ; /* be quiet */
1469                         else if (!strcmp(branch_name, "HEAD") &&
1470                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1471                                 puts(_("HEAD is up to date."));
1472                         else
1473                                 printf(_("Current branch %s is up to date.\n"),
1474                                        branch_name);
1475                         ret = !!finish_rebase(&options);
1476                         goto cleanup;
1477                 } else if (!(options.flags & REBASE_NO_QUIET))
1478                         ; /* be quiet */
1479                 else if (!strcmp(branch_name, "HEAD") &&
1480                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1481                         puts(_("HEAD is up to date, rebase forced."));
1482                 else
1483                         printf(_("Current branch %s is up to date, rebase "
1484                                  "forced.\n"), branch_name);
1485         }
1486
1487         /* If a hook exists, give it a chance to interrupt*/
1488         if (!ok_to_skip_pre_rebase &&
1489             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1490                         argc ? argv[0] : NULL, NULL))
1491                 die(_("The pre-rebase hook refused to rebase."));
1492
1493         if (options.flags & REBASE_DIFFSTAT) {
1494                 struct diff_options opts;
1495
1496                 if (options.flags & REBASE_VERBOSE) {
1497                         if (is_null_oid(&merge_base))
1498                                 printf(_("Changes to %s:\n"),
1499                                        oid_to_hex(&options.onto->object.oid));
1500                         else
1501                                 printf(_("Changes from %s to %s:\n"),
1502                                        oid_to_hex(&merge_base),
1503                                        oid_to_hex(&options.onto->object.oid));
1504                 }
1505
1506                 /* We want color (if set), but no pager */
1507                 diff_setup(&opts);
1508                 opts.stat_width = -1; /* use full terminal width */
1509                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1510                 opts.output_format |=
1511                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1512                 opts.detect_rename = DIFF_DETECT_RENAME;
1513                 diff_setup_done(&opts);
1514                 diff_tree_oid(is_null_oid(&merge_base) ?
1515                               the_hash_algo->empty_tree : &merge_base,
1516                               &options.onto->object.oid, "", &opts);
1517                 diffcore_std(&opts);
1518                 diff_flush(&opts);
1519         }
1520
1521         if (is_interactive(&options))
1522                 goto run_rebase;
1523
1524         /* Detach HEAD and reset the tree */
1525         if (options.flags & REBASE_NO_QUIET)
1526                 printf(_("First, rewinding head to replay your work on top of "
1527                          "it...\n"));
1528
1529         strbuf_addf(&msg, "%s: checkout %s",
1530                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
1531         if (reset_head(&options.onto->object.oid, "checkout", NULL,
1532                        RESET_HEAD_DETACH, NULL, msg.buf))
1533                 die(_("Could not detach HEAD"));
1534         strbuf_release(&msg);
1535
1536         /*
1537          * If the onto is a proper descendant of the tip of the branch, then
1538          * we just fast-forwarded.
1539          */
1540         strbuf_reset(&msg);
1541         if (!oidcmp(&merge_base, &options.orig_head)) {
1542                 printf(_("Fast-forwarded %s to %s.\n"),
1543                         branch_name, options.onto_name);
1544                 strbuf_addf(&msg, "rebase finished: %s onto %s",
1545                         options.head_name ? options.head_name : "detached HEAD",
1546                         oid_to_hex(&options.onto->object.oid));
1547                 reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1548                            "HEAD", msg.buf);
1549                 strbuf_release(&msg);
1550                 ret = !!finish_rebase(&options);
1551                 goto cleanup;
1552         }
1553
1554         strbuf_addf(&revisions, "%s..%s",
1555                     options.root ? oid_to_hex(&options.onto->object.oid) :
1556                     (options.restrict_revision ?
1557                      oid_to_hex(&options.restrict_revision->object.oid) :
1558                      oid_to_hex(&options.upstream->object.oid)),
1559                     oid_to_hex(&options.orig_head));
1560
1561         options.revisions = revisions.buf;
1562
1563 run_rebase:
1564         ret = !!run_specific_rebase(&options);
1565
1566 cleanup:
1567         strbuf_release(&revisions);
1568         free(options.head_name);
1569         free(options.gpg_sign_opt);
1570         free(options.cmd);
1571         free(squash_onto_name);
1572         return ret;
1573 }