builtin-receive-pack.c

   1 #include "cache.h"
   2 #include "pack.h"
   3 #include "refs.h"
   4 #include "pkt-line.h"
   5 #include "run-command.h"
   6 #include "exec_cmd.h"
   7 #include "commit.h"
   8 #include "object.h"
   9 #include "remote.h"
  10 #include "transport.h"
  11
  12 static const char receive_pack_usage[] = "git receive-pack <git-dir>";
  13
  14 enum deny_action {
  15         DENY_UNCONFIGURED,
  16         DENY_IGNORE,
  17         DENY_WARN,
  18         DENY_REFUSE,
  19 };
  20
  21 static int deny_deletes;
  22 static int deny_non_fast_forwards;
  23 static enum deny_action deny_current_branch = DENY_UNCONFIGURED;
  24 static enum deny_action deny_delete_current = DENY_UNCONFIGURED;
  25 static int receive_fsck_objects;
  26 static int receive_unpack_limit = -1;
  27 static int transfer_unpack_limit = -1;
  28 static int unpack_limit = 100;
  29 static int report_status;
  30 static const char *head_name;
  31
  32 static char capabilities[] = " report-status delete-refs ";
  33 static int capabilities_sent;
  34
  35 static enum deny_action parse_deny_action(const char *var, const char *value)
  36 {
  37         if (value) {
  38                 if (!strcasecmp(value, "ignore"))
  39                         return DENY_IGNORE;
  40                 if (!strcasecmp(value, "warn"))
  41                         return DENY_WARN;
  42                 if (!strcasecmp(value, "refuse"))
  43                         return DENY_REFUSE;
  44         }
  45         if (git_config_bool(var, value))
  46                 return DENY_REFUSE;
  47         return DENY_IGNORE;
  48 }
  49
  50 static int receive_pack_config(const char *var, const char *value, void *cb)
  51 {
  52         if (strcmp(var, "receive.denydeletes") == 0) {
  53                 deny_deletes = git_config_bool(var, value);
  54                 return 0;
  55         }
  56
  57         if (strcmp(var, "receive.denynonfastforwards") == 0) {
  58                 deny_non_fast_forwards = git_config_bool(var, value);
  59                 return 0;
  60         }
  61
  62         if (strcmp(var, "receive.unpacklimit") == 0) {
  63                 receive_unpack_limit = git_config_int(var, value);
  64                 return 0;
  65         }
  66
  67         if (strcmp(var, "transfer.unpacklimit") == 0) {
  68                 transfer_unpack_limit = git_config_int(var, value);
  69                 return 0;
  70         }
  71
  72         if (strcmp(var, "receive.fsckobjects") == 0) {
  73                 receive_fsck_objects = git_config_bool(var, value);
  74                 return 0;
  75         }
  76
  77         if (!strcmp(var, "receive.denycurrentbranch")) {
  78                 deny_current_branch = parse_deny_action(var, value);
  79                 return 0;
  80         }
  81
  82         if (strcmp(var, "receive.denydeletecurrent") == 0) {
  83                 deny_delete_current = parse_deny_action(var, value);
  84                 return 0;
  85         }
  86
  87         return git_default_config(var, value, cb);
  88 }
  89
  90 static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  91 {
  92         if (capabilities_sent)
  93                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  94         else
  95                 packet_write(1, "%s %s%c%s\n",
  96                              sha1_to_hex(sha1), path, 0, capabilities);
  97         capabilities_sent = 1;
  98         return 0;
  99 }
 100
 101 static void write_head_info(void)
 102 {
 103         for_each_ref(show_ref, NULL);
 104         if (!capabilities_sent)
 105                 show_ref("capabilities^{}", null_sha1, 0, NULL);
 106
 107 }
 108
 109 struct command {
 110         struct command *next;
 111         const char *error_string;
 112         unsigned char old_sha1[20];
 113         unsigned char new_sha1[20];
 114         char ref_name[FLEX_ARRAY]; /* more */
 115 };
 116
 117 static struct command *commands;
 118
 119 static const char pre_receive_hook[] = "hooks/pre-receive";
 120 static const char post_receive_hook[] = "hooks/post-receive";
 121
 122 static int hook_status(int code, const char *hook_name)
 123 {
 124         switch (code) {
 125         case 0:
 126                 return 0;
 127         case -ERR_RUN_COMMAND_FORK:
 128                 return error("hook fork failed");
 129         case -ERR_RUN_COMMAND_EXEC:
 130                 return error("hook execute failed");
 131         case -ERR_RUN_COMMAND_PIPE:
 132                 return error("hook pipe failed");
 133         case -ERR_RUN_COMMAND_WAITPID:
 134                 return error("waitpid failed");
 135         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 136                 return error("waitpid is confused");
 137         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 138                 return error("%s died of signal", hook_name);
 139         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 140                 return error("%s died strangely", hook_name);
 141         default:
 142                 error("%s exited with error code %d", hook_name, -code);
 143                 return -code;
 144         }
 145 }
 146
 147 static int run_receive_hook(const char *hook_name)
 148 {
 149         static char buf[sizeof(commands->old_sha1) * 2 + PATH_MAX + 4];
 150         struct command *cmd;
 151         struct child_process proc;
 152         const char *argv[2];
 153         int have_input = 0, code;
 154
 155         for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
 156                 if (!cmd->error_string)
 157                         have_input = 1;
 158         }
 159
 160         if (!have_input || access(hook_name, X_OK) < 0)
 161                 return 0;
 162
 163         argv[0] = hook_name;
 164         argv[1] = NULL;
 165
 166         memset(&proc, 0, sizeof(proc));
 167         proc.argv = argv;
 168         proc.in = -1;
 169         proc.stdout_to_stderr = 1;
 170
 171         code = start_command(&proc);
 172         if (code)
 173                 return hook_status(code, hook_name);
 174         for (cmd = commands; cmd; cmd = cmd->next) {
 175                 if (!cmd->error_string) {
 176                         size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
 177                                 sha1_to_hex(cmd->old_sha1),
 178                                 sha1_to_hex(cmd->new_sha1),
 179                                 cmd->ref_name);
 180                         if (write_in_full(proc.in, buf, n) != n)
 181                                 break;
 182                 }
 183         }
 184         close(proc.in);
 185         return hook_status(finish_command(&proc), hook_name);
 186 }
 187
 188 static int run_update_hook(struct command *cmd)
 189 {
 190         static const char update_hook[] = "hooks/update";
 191         struct child_process proc;
 192         const char *argv[5];
 193
 194         if (access(update_hook, X_OK) < 0)
 195                 return 0;
 196
 197         argv[0] = update_hook;
 198         argv[1] = cmd->ref_name;
 199         argv[2] = sha1_to_hex(cmd->old_sha1);
 200         argv[3] = sha1_to_hex(cmd->new_sha1);
 201         argv[4] = NULL;
 202
 203         memset(&proc, 0, sizeof(proc));
 204         proc.argv = argv;
 205         proc.no_stdin = 1;
 206         proc.stdout_to_stderr = 1;
 207
 208         return hook_status(run_command(&proc), update_hook);
 209 }
 210
 211 static int is_ref_checked_out(const char *ref)
 212 {
 213         if (is_bare_repository())
 214                 return 0;
 215
 216         if (!head_name)
 217                 return 0;
 218         return !strcmp(head_name, ref);
 219 }
 220
 221 static char *warn_unconfigured_deny_msg[] = {
 222         "Updating the currently checked out branch may cause confusion,",
 223         "as the index and work tree do not reflect changes that are in HEAD.",
 224         "As a result, you may see the changes you just pushed into it",
 225         "reverted when you run 'git diff' over there, and you may want",
 226         "to run 'git reset --hard' before starting to work to recover.",
 227         "",
 228         "You can set 'receive.denyCurrentBranch' configuration variable to",
 229         "'refuse' in the remote repository to forbid pushing into its",
 230         "current branch."
 231         "",
 232         "To allow pushing into the current branch, you can set it to 'ignore';",
 233         "but this is not recommended unless you arranged to update its work",
 234         "tree to match what you pushed in some other way.",
 235         "",
 236         "To squelch this message, you can set it to 'warn'.",
 237         "",
 238         "Note that the default will change in a future version of git",
 239         "to refuse updating the current branch unless you have the",
 240         "configuration variable set to either 'ignore' or 'warn'."
 241 };
 242
 243 static void warn_unconfigured_deny(void)
 244 {
 245         int i;
 246         for (i = 0; i < ARRAY_SIZE(warn_unconfigured_deny_msg); i++)
 247                 warning("%s", warn_unconfigured_deny_msg[i]);
 248 }
 249
 250 static char *warn_unconfigured_deny_delete_current_msg[] = {
 251         "Deleting the current branch can cause confusion by making the next",
 252         "'git clone' not check out any file.",
 253         "",
 254         "You can set 'receive.denyDeleteCurrent' configuration variable to",
 255         "'refuse' in the remote repository to disallow deleting the current",
 256         "branch.",
 257         "",
 258         "You can set it to 'ignore' to allow such a delete without a warning.",
 259         "",
 260         "To make this warning message less loud, you can set it to 'warn'.",
 261         "",
 262         "Note that the default will change in a future version of git",
 263         "to refuse deleting the current branch unless you have the",
 264         "configuration variable set to either 'ignore' or 'warn'."
 265 };
 266
 267 static void warn_unconfigured_deny_delete_current(void)
 268 {
 269         int i;
 270         for (i = 0;
 271              i < ARRAY_SIZE(warn_unconfigured_deny_delete_current_msg);
 272              i++)
 273                 warning("%s", warn_unconfigured_deny_delete_current_msg[i]);
 274 }
 275
 276 static const char *update(struct command *cmd)
 277 {
 278         const char *name = cmd->ref_name;
 279         unsigned char *old_sha1 = cmd->old_sha1;
 280         unsigned char *new_sha1 = cmd->new_sha1;
 281         struct ref_lock *lock;
 282
 283         /* only refs/... are allowed */
 284         if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
 285                 error("refusing to create funny ref '%s' remotely", name);
 286                 return "funny refname";
 287         }
 288
 289         if (is_ref_checked_out(name)) {
 290                 switch (deny_current_branch) {
 291                 case DENY_IGNORE:
 292                         break;
 293                 case DENY_UNCONFIGURED:
 294                 case DENY_WARN:
 295                         warning("updating the current branch");
 296                         if (deny_current_branch == DENY_UNCONFIGURED)
 297                                 warn_unconfigured_deny();
 298                         break;
 299                 case DENY_REFUSE:
 300                         error("refusing to update checked out branch: %s", name);
 301                         return "branch is currently checked out";
 302                 }
 303         }
 304
 305         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 306                 error("unpack should have generated %s, "
 307                       "but I can't find it!", sha1_to_hex(new_sha1));
 308                 return "bad pack";
 309         }
 310
 311         if (!is_null_sha1(old_sha1) && is_null_sha1(new_sha1)) {
 312                 if (deny_deletes && !prefixcmp(name, "refs/heads/")) {
 313                         error("denying ref deletion for %s", name);
 314                         return "deletion prohibited";
 315                 }
 316
 317                 if (!strcmp(name, head_name)) {
 318                         switch (deny_delete_current) {
 319                         case DENY_IGNORE:
 320                                 break;
 321                         case DENY_WARN:
 322                         case DENY_UNCONFIGURED:
 323                                 if (deny_delete_current == DENY_UNCONFIGURED)
 324                                         warn_unconfigured_deny_delete_current();
 325                                 warning("deleting the current branch");
 326                                 break;
 327                         case DENY_REFUSE:
 328                                 error("refusing to delete the current branch: %s", name);
 329                                 return "deletion of the current branch prohibited";
 330                         }
 331                 }
 332         }
 333
 334         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 335             !is_null_sha1(old_sha1) &&
 336             !prefixcmp(name, "refs/heads/")) {
 337                 struct object *old_object, *new_object;
 338                 struct commit *old_commit, *new_commit;
 339                 struct commit_list *bases, *ent;
 340
 341                 old_object = parse_object(old_sha1);
 342                 new_object = parse_object(new_sha1);
 343
 344                 if (!old_object || !new_object ||
 345                     old_object->type != OBJ_COMMIT ||
 346                     new_object->type != OBJ_COMMIT) {
 347                         error("bad sha1 objects for %s", name);
 348                         return "bad ref";
 349                 }
 350                 old_commit = (struct commit *)old_object;
 351                 new_commit = (struct commit *)new_object;
 352                 bases = get_merge_bases(old_commit, new_commit, 1);
 353                 for (ent = bases; ent; ent = ent->next)
 354                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 355                                 break;
 356                 free_commit_list(bases);
 357                 if (!ent) {
 358                         error("denying non-fast forward %s"
 359                               " (you should pull first)", name);
 360                         return "non-fast forward";
 361                 }
 362         }
 363         if (run_update_hook(cmd)) {
 364                 error("hook declined to update %s", name);
 365                 return "hook declined";
 366         }
 367
 368         if (is_null_sha1(new_sha1)) {
 369                 if (!parse_object(old_sha1)) {
 370                         warning ("Allowing deletion of corrupt ref.");
 371                         old_sha1 = NULL;
 372                 }
 373                 if (delete_ref(name, old_sha1, 0)) {
 374                         error("failed to delete %s", name);
 375                         return "failed to delete";
 376                 }
 377                 return NULL; /* good */
 378         }
 379         else {
 380                 lock = lock_any_ref_for_update(name, old_sha1, 0);
 381                 if (!lock) {
 382                         error("failed to lock %s", name);
 383                         return "failed to lock";
 384                 }
 385                 if (write_ref_sha1(lock, new_sha1, "push")) {
 386                         return "failed to write"; /* error() already called */
 387                 }
 388                 return NULL; /* good */
 389         }
 390 }
 391
 392 static char update_post_hook[] = "hooks/post-update";
 393
 394 static void run_update_post_hook(struct command *cmd)
 395 {
 396         struct command *cmd_p;
 397         int argc;
 398         const char **argv;
 399
 400         for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 401                 if (cmd_p->error_string)
 402                         continue;
 403                 argc++;
 404         }
 405         if (!argc || access(update_post_hook, X_OK) < 0)
 406                 return;
 407         argv = xmalloc(sizeof(*argv) * (2 + argc));
 408         argv[0] = update_post_hook;
 409
 410         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 411                 char *p;
 412                 if (cmd_p->error_string)
 413                         continue;
 414                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 415                 strcpy(p, cmd_p->ref_name);
 416                 argv[argc] = p;
 417                 argc++;
 418         }
 419         argv[argc] = NULL;
 420         run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
 421                 | RUN_COMMAND_STDOUT_TO_STDERR);
 422 }
 423
 424 static void execute_commands(const char *unpacker_error)
 425 {
 426         struct command *cmd = commands;
 427         unsigned char sha1[20];
 428
 429         if (unpacker_error) {
 430                 while (cmd) {
 431                         cmd->error_string = "n/a (unpacker error)";
 432                         cmd = cmd->next;
 433                 }
 434                 return;
 435         }
 436
 437         if (run_receive_hook(pre_receive_hook)) {
 438                 while (cmd) {
 439                         cmd->error_string = "pre-receive hook declined";
 440                         cmd = cmd->next;
 441                 }
 442                 return;
 443         }
 444
 445         head_name = resolve_ref("HEAD", sha1, 0, NULL);
 446
 447         while (cmd) {
 448                 cmd->error_string = update(cmd);
 449                 cmd = cmd->next;
 450         }
 451 }
 452
 453 static void read_head_info(void)
 454 {
 455         struct command **p = &commands;
 456         for (;;) {
 457                 static char line[1000];
 458                 unsigned char old_sha1[20], new_sha1[20];
 459                 struct command *cmd;
 460                 char *refname;
 461                 int len, reflen;
 462
 463                 len = packet_read_line(0, line, sizeof(line));
 464                 if (!len)
 465                         break;
 466                 if (line[len-1] == '\n')
 467                         line[--len] = 0;
 468                 if (len < 83 ||
 469                     line[40] != ' ' ||
 470                     line[81] != ' ' ||
 471                     get_sha1_hex(line, old_sha1) ||
 472                     get_sha1_hex(line + 41, new_sha1))
 473                         die("protocol error: expected old/new/ref, got '%s'",
 474                             line);
 475
 476                 refname = line + 82;
 477                 reflen = strlen(refname);
 478                 if (reflen + 82 < len) {
 479                         if (strstr(refname + reflen + 1, "report-status"))
 480                                 report_status = 1;
 481                 }
 482                 cmd = xmalloc(sizeof(struct command) + len - 80);
 483                 hashcpy(cmd->old_sha1, old_sha1);
 484                 hashcpy(cmd->new_sha1, new_sha1);
 485                 memcpy(cmd->ref_name, line + 82, len - 81);
 486                 cmd->error_string = NULL;
 487                 cmd->next = NULL;
 488                 *p = cmd;
 489                 p = &cmd->next;
 490         }
 491 }
 492
 493 static const char *parse_pack_header(struct pack_header *hdr)
 494 {
 495         switch (read_pack_header(0, hdr)) {
 496         case PH_ERROR_EOF:
 497                 return "eof before pack header was fully read";
 498
 499         case PH_ERROR_PACK_SIGNATURE:
 500                 return "protocol error (pack signature mismatch detected)";
 501
 502         case PH_ERROR_PROTOCOL:
 503                 return "protocol error (pack version unsupported)";
 504
 505         default:
 506                 return "unknown error in parse_pack_header";
 507
 508         case 0:
 509                 return NULL;
 510         }
 511 }
 512
 513 static const char *pack_lockfile;
 514
 515 static const char *unpack(void)
 516 {
 517         struct pack_header hdr;
 518         const char *hdr_err;
 519         char hdr_arg[38];
 520
 521         hdr_err = parse_pack_header(&hdr);
 522         if (hdr_err)
 523                 return hdr_err;
 524         snprintf(hdr_arg, sizeof(hdr_arg),
 525                         "--pack_header=%"PRIu32",%"PRIu32,
 526                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 527
 528         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 529                 int code, i = 0;
 530                 const char *unpacker[4];
 531                 unpacker[i++] = "unpack-objects";
 532                 if (receive_fsck_objects)
 533                         unpacker[i++] = "--strict";
 534                 unpacker[i++] = hdr_arg;
 535                 unpacker[i++] = NULL;
 536                 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
 537                 switch (code) {
 538                 case 0:
 539                         return NULL;
 540                 case -ERR_RUN_COMMAND_FORK:
 541                         return "unpack fork failed";
 542                 case -ERR_RUN_COMMAND_EXEC:
 543                         return "unpack execute failed";
 544                 case -ERR_RUN_COMMAND_WAITPID:
 545                         return "waitpid failed";
 546                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 547                         return "waitpid is confused";
 548                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 549                         return "unpacker died of signal";
 550                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 551                         return "unpacker died strangely";
 552                 default:
 553                         return "unpacker exited with error code";
 554                 }
 555         } else {
 556                 const char *keeper[7];
 557                 int s, status, i = 0;
 558                 char keep_arg[256];
 559                 struct child_process ip;
 560
 561                 s = sprintf(keep_arg, "--keep=receive-pack %"PRIuMAX" on ", (uintmax_t) getpid());
 562                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 563                         strcpy(keep_arg + s, "localhost");
 564
 565                 keeper[i++] = "index-pack";
 566                 keeper[i++] = "--stdin";
 567                 if (receive_fsck_objects)
 568                         keeper[i++] = "--strict";
 569                 keeper[i++] = "--fix-thin";
 570                 keeper[i++] = hdr_arg;
 571                 keeper[i++] = keep_arg;
 572                 keeper[i++] = NULL;
 573                 memset(&ip, 0, sizeof(ip));
 574                 ip.argv = keeper;
 575                 ip.out = -1;
 576                 ip.git_cmd = 1;
 577                 if (start_command(&ip))
 578                         return "index-pack fork failed";
 579                 pack_lockfile = index_pack_lockfile(ip.out);
 580                 close(ip.out);
 581                 status = finish_command(&ip);
 582                 if (!status) {
 583                         reprepare_packed_git();
 584                         return NULL;
 585                 }
 586                 return "index-pack abnormal exit";
 587         }
 588 }
 589
 590 static void report(const char *unpack_status)
 591 {
 592         struct command *cmd;
 593         packet_write(1, "unpack %s\n",
 594                      unpack_status ? unpack_status : "ok");
 595         for (cmd = commands; cmd; cmd = cmd->next) {
 596                 if (!cmd->error_string)
 597                         packet_write(1, "ok %s\n",
 598                                      cmd->ref_name);
 599                 else
 600                         packet_write(1, "ng %s %s\n",
 601                                      cmd->ref_name, cmd->error_string);
 602         }
 603         packet_flush(1);
 604 }
 605
 606 static int delete_only(struct command *cmd)
 607 {
 608         while (cmd) {
 609                 if (!is_null_sha1(cmd->new_sha1))
 610                         return 0;
 611                 cmd = cmd->next;
 612         }
 613         return 1;
 614 }
 615
 616 static int add_refs_from_alternate(struct alternate_object_database *e, void *unused)
 617 {
 618         char *other;
 619         size_t len;
 620         struct remote *remote;
 621         struct transport *transport;
 622         const struct ref *extra;
 623
 624         e->name[-1] = '\0';
 625         other = xstrdup(make_absolute_path(e->base));
 626         e->name[-1] = '/';
 627         len = strlen(other);
 628
 629         while (other[len-1] == '/')
 630                 other[--len] = '\0';
 631         if (len < 8 || memcmp(other + len - 8, "/objects", 8))
 632                 return 0;
 633         /* Is this a git repository with refs? */
 634         memcpy(other + len - 8, "/refs", 6);
 635         if (!is_directory(other))
 636                 return 0;
 637         other[len - 8] = '\0';
 638         remote = remote_get(other);
 639         transport = transport_get(remote, other);
 640         for (extra = transport_get_remote_refs(transport);
 641              extra;
 642              extra = extra->next) {
 643                 add_extra_ref(".have", extra->old_sha1, 0);
 644         }
 645         transport_disconnect(transport);
 646         free(other);
 647         return 0;
 648 }
 649
 650 static void add_alternate_refs(void)
 651 {
 652         foreach_alt_odb(add_refs_from_alternate, NULL);
 653 }
 654
 655 int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 656 {
 657         int i;
 658         char *dir = NULL;
 659
 660         argv++;
 661         for (i = 1; i < argc; i++) {
 662                 const char *arg = *argv++;
 663
 664                 if (*arg == '-') {
 665                         /* Do flag handling here */
 666                         usage(receive_pack_usage);
 667                 }
 668                 if (dir)
 669                         usage(receive_pack_usage);
 670                 dir = xstrdup(arg);
 671         }
 672         if (!dir)
 673                 usage(receive_pack_usage);
 674
 675         setup_path();
 676
 677         if (!enter_repo(dir, 0))
 678                 die("'%s' does not appear to be a git repository", dir);
 679
 680         if (is_repository_shallow())
 681                 die("attempt to push into a shallow repository");
 682
 683         git_config(receive_pack_config, NULL);
 684
 685         if (0 <= transfer_unpack_limit)
 686                 unpack_limit = transfer_unpack_limit;
 687         else if (0 <= receive_unpack_limit)
 688                 unpack_limit = receive_unpack_limit;
 689
 690         add_alternate_refs();
 691         write_head_info();
 692         clear_extra_refs();
 693
 694         /* EOF */
 695         packet_flush(1);
 696
 697         read_head_info();
 698         if (commands) {
 699                 const char *unpack_status = NULL;
 700
 701                 if (!delete_only(commands))
 702                         unpack_status = unpack();
 703                 execute_commands(unpack_status);
 704                 if (pack_lockfile)
 705                         unlink_or_warn(pack_lockfile);
 706                 if (report_status)
 707                         report(unpack_status);
 708                 run_receive_hook(post_receive_hook);
 709                 run_update_post_hook(commands);
 710         }
 711         return 0;
 712 }