transport-helper.c

   1 #include "cache.h"
   2 #include "transport.h"
   3 #include "quote.h"
   4 #include "run-command.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "revision.h"
   8 #include "quote.h"
   9 #include "remote.h"
  10
  11 static int debug;
  12
  13 struct helper_data
  14 {
  15         const char *name;
  16         struct child_process *helper;
  17         FILE *out;
  18         unsigned fetch : 1,
  19                 import : 1,
  20                 option : 1,
  21                 push : 1,
  22                 connect : 1,
  23                 no_disconnect_req : 1;
  24         /* These go from remote name (as in "list") to private name */
  25         struct refspec *refspecs;
  26         int refspec_nr;
  27         /* Transport options for fetch-pack/send-pack (should one of
  28          * those be invoked).
  29          */
  30         struct git_transport_options transport_options;
  31 };
  32
  33 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  34 {
  35         if (debug)
  36                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  37         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  38                 != buffer->len)
  39                 die_errno("Full write to remote helper failed");
  40 }
  41
  42 static int recvline_fh(FILE *helper, struct strbuf *buffer)
  43 {
  44         strbuf_reset(buffer);
  45         if (debug)
  46                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  47         if (strbuf_getline(buffer, helper, '\n') == EOF) {
  48                 if (debug)
  49                         fprintf(stderr, "Debug: Remote helper quit.\n");
  50                 exit(128);
  51         }
  52
  53         if (debug)
  54                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  55         return 0;
  56 }
  57
  58 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  59 {
  60         return recvline_fh(helper->out, buffer);
  61 }
  62
  63 static void xchgline(struct helper_data *helper, struct strbuf *buffer)
  64 {
  65         sendline(helper, buffer);
  66         recvline(helper, buffer);
  67 }
  68
  69 static void write_constant(int fd, const char *str)
  70 {
  71         if (debug)
  72                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  73         if (write_in_full(fd, str, strlen(str)) != strlen(str))
  74                 die_errno("Full write to remote helper failed");
  75 }
  76
  77 const char *remove_ext_force(const char *url)
  78 {
  79         if (url) {
  80                 const char *colon = strchr(url, ':');
  81                 if (colon && colon[1] == ':')
  82                         return colon + 2;
  83         }
  84         return url;
  85 }
  86
  87 static void do_take_over(struct transport *transport)
  88 {
  89         struct helper_data *data;
  90         data = (struct helper_data *)transport->data;
  91         transport_take_over(transport, data->helper);
  92         fclose(data->out);
  93         free(data);
  94 }
  95
  96 static struct child_process *get_helper(struct transport *transport)
  97 {
  98         struct helper_data *data = transport->data;
  99         struct strbuf buf = STRBUF_INIT;
 100         struct child_process *helper;
 101         const char **refspecs = NULL;
 102         int refspec_nr = 0;
 103         int refspec_alloc = 0;
 104         int duped;
 105         int code;
 106
 107         if (data->helper)
 108                 return data->helper;
 109
 110         helper = xcalloc(1, sizeof(*helper));
 111         helper->in = -1;
 112         helper->out = -1;
 113         helper->err = 0;
 114         helper->argv = xcalloc(4, sizeof(*helper->argv));
 115         strbuf_addf(&buf, "git-remote-%s", data->name);
 116         helper->argv[0] = strbuf_detach(&buf, NULL);
 117         helper->argv[1] = transport->remote->name;
 118         helper->argv[2] = remove_ext_force(transport->url);
 119         helper->git_cmd = 0;
 120         helper->silent_exec_failure = 1;
 121         code = start_command(helper);
 122         if (code < 0 && errno == ENOENT)
 123                 die("Unable to find remote helper for '%s'", data->name);
 124         else if (code != 0)
 125                 exit(code);
 126
 127         data->helper = helper;
 128         data->no_disconnect_req = 0;
 129
 130         /*
 131          * Open the output as FILE* so strbuf_getline() can be used.
 132          * Do this with duped fd because fclose() will close the fd,
 133          * and stuff like taking over will require the fd to remain.
 134          */
 135         duped = dup(helper->out);
 136         if (duped < 0)
 137                 die_errno("Can't dup helper output fd");
 138         data->out = xfdopen(duped, "r");
 139
 140         write_constant(helper->in, "capabilities\n");
 141
 142         while (1) {
 143                 const char *capname;
 144                 int mandatory = 0;
 145                 recvline(data, &buf);
 146
 147                 if (!*buf.buf)
 148                         break;
 149
 150                 if (*buf.buf == '*') {
 151                         capname = buf.buf + 1;
 152                         mandatory = 1;
 153                 } else
 154                         capname = buf.buf;
 155
 156                 if (debug)
 157                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 158                 if (!strcmp(capname, "fetch"))
 159                         data->fetch = 1;
 160                 else if (!strcmp(capname, "option"))
 161                         data->option = 1;
 162                 else if (!strcmp(capname, "push"))
 163                         data->push = 1;
 164                 else if (!strcmp(capname, "import"))
 165                         data->import = 1;
 166                 else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
 167                         ALLOC_GROW(refspecs,
 168                                    refspec_nr + 1,
 169                                    refspec_alloc);
 170                         refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
 171                 } else if (!strcmp(capname, "connect")) {
 172                         data->connect = 1;
 173                 } else if (!strcmp(buf.buf, "gitdir")) {
 174                         struct strbuf gitdir = STRBUF_INIT;
 175                         strbuf_addf(&gitdir, "gitdir %s\n", get_git_dir());
 176                         sendline(data, &gitdir);
 177                         strbuf_release(&gitdir);
 178                 } else if (mandatory) {
 179                         die("Unknown mandatory capability %s. This remote "
 180                             "helper probably needs newer version of Git.\n",
 181                             capname);
 182                 }
 183         }
 184         if (refspecs) {
 185                 int i;
 186                 data->refspec_nr = refspec_nr;
 187                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 188                 for (i = 0; i < refspec_nr; i++) {
 189                         free((char *)refspecs[i]);
 190                 }
 191                 free(refspecs);
 192         }
 193         strbuf_release(&buf);
 194         if (debug)
 195                 fprintf(stderr, "Debug: Capabilities complete.\n");
 196         return data->helper;
 197 }
 198
 199 static int disconnect_helper(struct transport *transport)
 200 {
 201         struct helper_data *data = transport->data;
 202         struct strbuf buf = STRBUF_INIT;
 203
 204         if (data->helper) {
 205                 if (debug)
 206                         fprintf(stderr, "Debug: Disconnecting.\n");
 207                 if (!data->no_disconnect_req) {
 208                         strbuf_addf(&buf, "\n");
 209                         sendline(data, &buf);
 210                 }
 211                 close(data->helper->in);
 212                 close(data->helper->out);
 213                 fclose(data->out);
 214                 finish_command(data->helper);
 215                 free((char *)data->helper->argv[0]);
 216                 free(data->helper->argv);
 217                 free(data->helper);
 218                 data->helper = NULL;
 219         }
 220         return 0;
 221 }
 222
 223 static const char *unsupported_options[] = {
 224         TRANS_OPT_UPLOADPACK,
 225         TRANS_OPT_RECEIVEPACK,
 226         TRANS_OPT_THIN,
 227         TRANS_OPT_KEEP
 228         };
 229 static const char *boolean_options[] = {
 230         TRANS_OPT_THIN,
 231         TRANS_OPT_KEEP,
 232         TRANS_OPT_FOLLOWTAGS
 233         };
 234
 235 static int set_helper_option(struct transport *transport,
 236                           const char *name, const char *value)
 237 {
 238         struct helper_data *data = transport->data;
 239         struct strbuf buf = STRBUF_INIT;
 240         int i, ret, is_bool = 0;
 241
 242         get_helper(transport);
 243
 244         if (!data->option)
 245                 return 1;
 246
 247         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 248                 if (!strcmp(name, unsupported_options[i]))
 249                         return 1;
 250         }
 251
 252         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 253                 if (!strcmp(name, boolean_options[i])) {
 254                         is_bool = 1;
 255                         break;
 256                 }
 257         }
 258
 259         strbuf_addf(&buf, "option %s ", name);
 260         if (is_bool)
 261                 strbuf_addstr(&buf, value ? "true" : "false");
 262         else
 263                 quote_c_style(value, &buf, NULL, 0);
 264         strbuf_addch(&buf, '\n');
 265
 266         xchgline(data, &buf);
 267
 268         if (!strcmp(buf.buf, "ok"))
 269                 ret = 0;
 270         else if (!prefixcmp(buf.buf, "error")) {
 271                 ret = -1;
 272         } else if (!strcmp(buf.buf, "unsupported"))
 273                 ret = 1;
 274         else {
 275                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 276                 ret = 1;
 277         }
 278         strbuf_release(&buf);
 279         return ret;
 280 }
 281
 282 static void standard_options(struct transport *t)
 283 {
 284         char buf[16];
 285         int n;
 286         int v = t->verbose;
 287
 288         set_helper_option(t, "progress", t->progress ? "true" : "false");
 289
 290         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 291         if (n >= sizeof(buf))
 292                 die("impossibly large verbosity value");
 293         set_helper_option(t, "verbosity", buf);
 294 }
 295
 296 static int release_helper(struct transport *transport)
 297 {
 298         struct helper_data *data = transport->data;
 299         free_refspec(data->refspec_nr, data->refspecs);
 300         data->refspecs = NULL;
 301         disconnect_helper(transport);
 302         free(transport->data);
 303         return 0;
 304 }
 305
 306 static int fetch_with_fetch(struct transport *transport,
 307                             int nr_heads, struct ref **to_fetch)
 308 {
 309         struct helper_data *data = transport->data;
 310         int i;
 311         struct strbuf buf = STRBUF_INIT;
 312
 313         standard_options(transport);
 314
 315         for (i = 0; i < nr_heads; i++) {
 316                 const struct ref *posn = to_fetch[i];
 317                 if (posn->status & REF_STATUS_UPTODATE)
 318                         continue;
 319
 320                 strbuf_addf(&buf, "fetch %s %s\n",
 321                             sha1_to_hex(posn->old_sha1), posn->name);
 322         }
 323
 324         strbuf_addch(&buf, '\n');
 325         sendline(data, &buf);
 326
 327         while (1) {
 328                 recvline(data, &buf);
 329
 330                 if (!prefixcmp(buf.buf, "lock ")) {
 331                         const char *name = buf.buf + 5;
 332                         if (transport->pack_lockfile)
 333                                 warning("%s also locked %s", data->name, name);
 334                         else
 335                                 transport->pack_lockfile = xstrdup(name);
 336                 }
 337                 else if (!buf.len)
 338                         break;
 339                 else
 340                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 341         }
 342         strbuf_release(&buf);
 343         return 0;
 344 }
 345
 346 static int get_importer(struct transport *transport, struct child_process *fastimport)
 347 {
 348         struct child_process *helper = get_helper(transport);
 349         memset(fastimport, 0, sizeof(*fastimport));
 350         fastimport->in = helper->out;
 351         fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
 352         fastimport->argv[0] = "fast-import";
 353         fastimport->argv[1] = "--quiet";
 354
 355         fastimport->git_cmd = 1;
 356         return start_command(fastimport);
 357 }
 358
 359 static int fetch_with_import(struct transport *transport,
 360                              int nr_heads, struct ref **to_fetch)
 361 {
 362         struct child_process fastimport;
 363         struct helper_data *data = transport->data;
 364         int i;
 365         struct ref *posn;
 366         struct strbuf buf = STRBUF_INIT;
 367
 368         get_helper(transport);
 369
 370         if (get_importer(transport, &fastimport))
 371                 die("Couldn't run fast-import");
 372
 373         for (i = 0; i < nr_heads; i++) {
 374                 posn = to_fetch[i];
 375                 if (posn->status & REF_STATUS_UPTODATE)
 376                         continue;
 377
 378                 strbuf_addf(&buf, "import %s\n", posn->name);
 379                 sendline(data, &buf);
 380                 strbuf_reset(&buf);
 381         }
 382         disconnect_helper(transport);
 383         finish_command(&fastimport);
 384         free(fastimport.argv);
 385         fastimport.argv = NULL;
 386
 387         for (i = 0; i < nr_heads; i++) {
 388                 char *private;
 389                 posn = to_fetch[i];
 390                 if (posn->status & REF_STATUS_UPTODATE)
 391                         continue;
 392                 if (data->refspecs)
 393                         private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 394                 else
 395                         private = strdup(posn->name);
 396                 read_ref(private, posn->old_sha1);
 397                 free(private);
 398         }
 399         strbuf_release(&buf);
 400         return 0;
 401 }
 402
 403 static int process_connect_service(struct transport *transport,
 404                                    const char *name, const char *exec)
 405 {
 406         struct helper_data *data = transport->data;
 407         struct strbuf cmdbuf = STRBUF_INIT;
 408         struct child_process *helper;
 409         int r, duped, ret = 0;
 410         FILE *input;
 411
 412         helper = get_helper(transport);
 413
 414         /*
 415          * Yes, dup the pipe another time, as we need unbuffered version
 416          * of input pipe as FILE*. fclose() closes the underlying fd and
 417          * stream buffering only can be changed before first I/O operation
 418          * on it.
 419          */
 420         duped = dup(helper->out);
 421         if (duped < 0)
 422                 die_errno("Can't dup helper output fd");
 423         input = xfdopen(duped, "r");
 424         setvbuf(input, NULL, _IONBF, 0);
 425
 426         /*
 427          * Handle --upload-pack and friends. This is fire and forget...
 428          * just warn if it fails.
 429          */
 430         if (strcmp(name, exec)) {
 431                 r = set_helper_option(transport, "servpath", exec);
 432                 if (r > 0)
 433                         warning("Setting remote service path not supported by protocol.");
 434                 else if (r < 0)
 435                         warning("Invalid remote service path.");
 436         }
 437
 438         if (data->connect)
 439                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 440         else
 441                 goto exit;
 442
 443         sendline(data, &cmdbuf);
 444         recvline_fh(input, &cmdbuf);
 445         if (!strcmp(cmdbuf.buf, "")) {
 446                 data->no_disconnect_req = 1;
 447                 if (debug)
 448                         fprintf(stderr, "Debug: Smart transport connection "
 449                                 "ready.\n");
 450                 ret = 1;
 451         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 452                 if (debug)
 453                         fprintf(stderr, "Debug: Falling back to dumb "
 454                                 "transport.\n");
 455         } else
 456                 die("Unknown response to connect: %s",
 457                         cmdbuf.buf);
 458
 459 exit:
 460         fclose(input);
 461         return ret;
 462 }
 463
 464 static int process_connect(struct transport *transport,
 465                                      int for_push)
 466 {
 467         struct helper_data *data = transport->data;
 468         const char *name;
 469         const char *exec;
 470
 471         name = for_push ? "git-receive-pack" : "git-upload-pack";
 472         if (for_push)
 473                 exec = data->transport_options.receivepack;
 474         else
 475                 exec = data->transport_options.uploadpack;
 476
 477         return process_connect_service(transport, name, exec);
 478 }
 479
 480 static int connect_helper(struct transport *transport, const char *name,
 481                    const char *exec, int fd[2])
 482 {
 483         struct helper_data *data = transport->data;
 484
 485         /* Get_helper so connect is inited. */
 486         get_helper(transport);
 487         if (!data->connect)
 488                 die("Operation not supported by protocol.");
 489
 490         if (!process_connect_service(transport, name, exec))
 491                 die("Can't connect to subservice %s.", name);
 492
 493         fd[0] = data->helper->out;
 494         fd[1] = data->helper->in;
 495         return 0;
 496 }
 497
 498 static int fetch(struct transport *transport,
 499                  int nr_heads, struct ref **to_fetch)
 500 {
 501         struct helper_data *data = transport->data;
 502         int i, count;
 503
 504         if (process_connect(transport, 0)) {
 505                 do_take_over(transport);
 506                 return transport->fetch(transport, nr_heads, to_fetch);
 507         }
 508
 509         count = 0;
 510         for (i = 0; i < nr_heads; i++)
 511                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 512                         count++;
 513
 514         if (!count)
 515                 return 0;
 516
 517         if (data->fetch)
 518                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 519
 520         if (data->import)
 521                 return fetch_with_import(transport, nr_heads, to_fetch);
 522
 523         return -1;
 524 }
 525
 526 static int push_refs(struct transport *transport,
 527                 struct ref *remote_refs, int flags)
 528 {
 529         int force_all = flags & TRANSPORT_PUSH_FORCE;
 530         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 531         struct helper_data *data = transport->data;
 532         struct strbuf buf = STRBUF_INIT;
 533         struct child_process *helper;
 534         struct ref *ref;
 535
 536         if (process_connect(transport, 1)) {
 537                 do_take_over(transport);
 538                 return transport->push_refs(transport, remote_refs, flags);
 539         }
 540
 541         if (!remote_refs) {
 542                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 543                         "Perhaps you should specify a branch such as 'master'.\n");
 544                 return 0;
 545         }
 546
 547         helper = get_helper(transport);
 548         if (!data->push)
 549                 return 1;
 550
 551         for (ref = remote_refs; ref; ref = ref->next) {
 552                 if (!ref->peer_ref && !mirror)
 553                         continue;
 554
 555                 /* Check for statuses set by set_ref_status_for_push() */
 556                 switch (ref->status) {
 557                 case REF_STATUS_REJECT_NONFASTFORWARD:
 558                 case REF_STATUS_UPTODATE:
 559                         continue;
 560                 default:
 561                         ; /* do nothing */
 562                 }
 563
 564                 if (force_all)
 565                         ref->force = 1;
 566
 567                 strbuf_addstr(&buf, "push ");
 568                 if (!ref->deletion) {
 569                         if (ref->force)
 570                                 strbuf_addch(&buf, '+');
 571                         if (ref->peer_ref)
 572                                 strbuf_addstr(&buf, ref->peer_ref->name);
 573                         else
 574                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 575                 }
 576                 strbuf_addch(&buf, ':');
 577                 strbuf_addstr(&buf, ref->name);
 578                 strbuf_addch(&buf, '\n');
 579         }
 580         if (buf.len == 0)
 581                 return 0;
 582
 583         standard_options(transport);
 584
 585         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 586                 if (set_helper_option(transport, "dry-run", "true") != 0)
 587                         die("helper %s does not support dry-run", data->name);
 588         }
 589
 590         strbuf_addch(&buf, '\n');
 591         sendline(data, &buf);
 592
 593         ref = remote_refs;
 594         while (1) {
 595                 char *refname, *msg;
 596                 int status;
 597
 598                 recvline(data, &buf);
 599                 if (!buf.len)
 600                         break;
 601
 602                 if (!prefixcmp(buf.buf, "ok ")) {
 603                         status = REF_STATUS_OK;
 604                         refname = buf.buf + 3;
 605                 } else if (!prefixcmp(buf.buf, "error ")) {
 606                         status = REF_STATUS_REMOTE_REJECT;
 607                         refname = buf.buf + 6;
 608                 } else
 609                         die("expected ok/error, helper said '%s'\n", buf.buf);
 610
 611                 msg = strchr(refname, ' ');
 612                 if (msg) {
 613                         struct strbuf msg_buf = STRBUF_INIT;
 614                         const char *end;
 615
 616                         *msg++ = '\0';
 617                         if (!unquote_c_style(&msg_buf, msg, &end))
 618                                 msg = strbuf_detach(&msg_buf, NULL);
 619                         else
 620                                 msg = xstrdup(msg);
 621                         strbuf_release(&msg_buf);
 622
 623                         if (!strcmp(msg, "no match")) {
 624                                 status = REF_STATUS_NONE;
 625                                 free(msg);
 626                                 msg = NULL;
 627                         }
 628                         else if (!strcmp(msg, "up to date")) {
 629                                 status = REF_STATUS_UPTODATE;
 630                                 free(msg);
 631                                 msg = NULL;
 632                         }
 633                         else if (!strcmp(msg, "non-fast forward")) {
 634                                 status = REF_STATUS_REJECT_NONFASTFORWARD;
 635                                 free(msg);
 636                                 msg = NULL;
 637                         }
 638                 }
 639
 640                 if (ref)
 641                         ref = find_ref_by_name(ref, refname);
 642                 if (!ref)
 643                         ref = find_ref_by_name(remote_refs, refname);
 644                 if (!ref) {
 645                         warning("helper reported unexpected status of %s", refname);
 646                         continue;
 647                 }
 648
 649                 if (ref->status != REF_STATUS_NONE) {
 650                         /*
 651                          * Earlier, the ref was marked not to be pushed, so ignore the ref
 652                          * status reported by the remote helper if the latter is 'no match'.
 653                          */
 654                         if (status == REF_STATUS_NONE)
 655                                 continue;
 656                 }
 657
 658                 ref->status = status;
 659                 ref->remote_status = msg;
 660         }
 661         strbuf_release(&buf);
 662         return 0;
 663 }
 664
 665 static int has_attribute(const char *attrs, const char *attr) {
 666         int len;
 667         if (!attrs)
 668                 return 0;
 669
 670         len = strlen(attr);
 671         for (;;) {
 672                 const char *space = strchrnul(attrs, ' ');
 673                 if (len == space - attrs && !strncmp(attrs, attr, len))
 674                         return 1;
 675                 if (!*space)
 676                         return 0;
 677                 attrs = space + 1;
 678         }
 679 }
 680
 681 static struct ref *get_refs_list(struct transport *transport, int for_push)
 682 {
 683         struct helper_data *data = transport->data;
 684         struct child_process *helper;
 685         struct ref *ret = NULL;
 686         struct ref **tail = &ret;
 687         struct ref *posn;
 688         struct strbuf buf = STRBUF_INIT;
 689
 690         helper = get_helper(transport);
 691
 692         if (process_connect(transport, for_push)) {
 693                 do_take_over(transport);
 694                 return transport->get_refs_list(transport, for_push);
 695         }
 696
 697         if (data->push && for_push)
 698                 write_str_in_full(helper->in, "list for-push\n");
 699         else
 700                 write_str_in_full(helper->in, "list\n");
 701
 702         while (1) {
 703                 char *eov, *eon;
 704                 recvline(data, &buf);
 705
 706                 if (!*buf.buf)
 707                         break;
 708
 709                 eov = strchr(buf.buf, ' ');
 710                 if (!eov)
 711                         die("Malformed response in ref list: %s", buf.buf);
 712                 eon = strchr(eov + 1, ' ');
 713                 *eov = '\0';
 714                 if (eon)
 715                         *eon = '\0';
 716                 *tail = alloc_ref(eov + 1);
 717                 if (buf.buf[0] == '@')
 718                         (*tail)->symref = xstrdup(buf.buf + 1);
 719                 else if (buf.buf[0] != '?')
 720                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
 721                 if (eon) {
 722                         if (has_attribute(eon + 1, "unchanged")) {
 723                                 (*tail)->status |= REF_STATUS_UPTODATE;
 724                                 read_ref((*tail)->name, (*tail)->old_sha1);
 725                         }
 726                 }
 727                 tail = &((*tail)->next);
 728         }
 729         if (debug)
 730                 fprintf(stderr, "Debug: Read ref listing.\n");
 731         strbuf_release(&buf);
 732
 733         for (posn = ret; posn; posn = posn->next)
 734                 resolve_remote_symref(posn, ret);
 735
 736         return ret;
 737 }
 738
 739 int transport_helper_init(struct transport *transport, const char *name)
 740 {
 741         struct helper_data *data = xcalloc(sizeof(*data), 1);
 742         data->name = name;
 743
 744         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
 745                 debug = 1;
 746
 747         transport->data = data;
 748         transport->set_option = set_helper_option;
 749         transport->get_refs_list = get_refs_list;
 750         transport->fetch = fetch;
 751         transport->push_refs = push_refs;
 752         transport->disconnect = release_helper;
 753         transport->connect = connect_helper;
 754         transport->smart_options = &(data->transport_options);
 755         return 0;
 756 }