git.oblomov.eu Git - git/blob - remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8 #include "tag.h"
   9 #include "string-list.h"
  10 #include "mergesort.h"
  11
  12 enum map_direction { FROM_SRC, FROM_DST };
  13
  14 static struct refspec s_tag_refspec = {
  15         0,
  16         1,
  17         0,
  18         0,
  19         "refs/tags/*",
  20         "refs/tags/*"
  21 };
  22
  23 const struct refspec *tag_refspec = &s_tag_refspec;
  24
  25 struct counted_string {
  26         size_t len;
  27         const char *s;
  28 };
  29 struct rewrite {
  30         const char *base;
  31         size_t baselen;
  32         struct counted_string *instead_of;
  33         int instead_of_nr;
  34         int instead_of_alloc;
  35 };
  36 struct rewrites {
  37         struct rewrite **rewrite;
  38         int rewrite_alloc;
  39         int rewrite_nr;
  40 };
  41
  42 static struct remote **remotes;
  43 static int remotes_alloc;
  44 static int remotes_nr;
  45
  46 static struct branch **branches;
  47 static int branches_alloc;
  48 static int branches_nr;
  49
  50 static struct branch *current_branch;
  51 static const char *default_remote_name;
  52 static const char *branch_pushremote_name;
  53 static const char *pushremote_name;
  54 static int explicit_default_remote_name;
  55
  56 static struct rewrites rewrites;
  57 static struct rewrites rewrites_push;
  58
  59 #define BUF_SIZE (2048)
  60 static char buffer[BUF_SIZE];
  61
  62 static int valid_remote(const struct remote *remote)
  63 {
  64         return (!!remote->url) || (!!remote->foreign_vcs);
  65 }
  66
  67 static const char *alias_url(const char *url, struct rewrites *r)
  68 {
  69         int i, j;
  70         char *ret;
  71         struct counted_string *longest;
  72         int longest_i;
  73
  74         longest = NULL;
  75         longest_i = -1;
  76         for (i = 0; i < r->rewrite_nr; i++) {
  77                 if (!r->rewrite[i])
  78                         continue;
  79                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  80                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  81                             (!longest ||
  82                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  83                                 longest = &(r->rewrite[i]->instead_of[j]);
  84                                 longest_i = i;
  85                         }
  86                 }
  87         }
  88         if (!longest)
  89                 return url;
  90
  91         ret = xmalloc(r->rewrite[longest_i]->baselen +
  92                      (strlen(url) - longest->len) + 1);
  93         strcpy(ret, r->rewrite[longest_i]->base);
  94         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  95         return ret;
  96 }
  97
  98 static void add_push_refspec(struct remote *remote, const char *ref)
  99 {
 100         ALLOC_GROW(remote->push_refspec,
 101                    remote->push_refspec_nr + 1,
 102                    remote->push_refspec_alloc);
 103         remote->push_refspec[remote->push_refspec_nr++] = ref;
 104 }
 105
 106 static void add_fetch_refspec(struct remote *remote, const char *ref)
 107 {
 108         ALLOC_GROW(remote->fetch_refspec,
 109                    remote->fetch_refspec_nr + 1,
 110                    remote->fetch_refspec_alloc);
 111         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 112 }
 113
 114 static void add_url(struct remote *remote, const char *url)
 115 {
 116         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 117         remote->url[remote->url_nr++] = url;
 118 }
 119
 120 static void add_pushurl(struct remote *remote, const char *pushurl)
 121 {
 122         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 123         remote->pushurl[remote->pushurl_nr++] = pushurl;
 124 }
 125
 126 static void add_pushurl_alias(struct remote *remote, const char *url)
 127 {
 128         const char *pushurl = alias_url(url, &rewrites_push);
 129         if (pushurl != url)
 130                 add_pushurl(remote, pushurl);
 131 }
 132
 133 static void add_url_alias(struct remote *remote, const char *url)
 134 {
 135         add_url(remote, alias_url(url, &rewrites));
 136         add_pushurl_alias(remote, url);
 137 }
 138
 139 static struct remote *make_remote(const char *name, int len)
 140 {
 141         struct remote *ret;
 142         int i;
 143
 144         for (i = 0; i < remotes_nr; i++) {
 145                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 146                            !remotes[i]->name[len]) :
 147                     !strcmp(name, remotes[i]->name))
 148                         return remotes[i];
 149         }
 150
 151         ret = xcalloc(1, sizeof(struct remote));
 152         ret->prune = -1;  /* unspecified */
 153         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 154         remotes[remotes_nr++] = ret;
 155         if (len)
 156                 ret->name = xstrndup(name, len);
 157         else
 158                 ret->name = xstrdup(name);
 159         return ret;
 160 }
 161
 162 static void add_merge(struct branch *branch, const char *name)
 163 {
 164         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 165                    branch->merge_alloc);
 166         branch->merge_name[branch->merge_nr++] = name;
 167 }
 168
 169 static struct branch *make_branch(const char *name, int len)
 170 {
 171         struct branch *ret;
 172         int i;
 173
 174         for (i = 0; i < branches_nr; i++) {
 175                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 176                            !branches[i]->name[len]) :
 177                     !strcmp(name, branches[i]->name))
 178                         return branches[i];
 179         }
 180
 181         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 182         ret = xcalloc(1, sizeof(struct branch));
 183         branches[branches_nr++] = ret;
 184         if (len)
 185                 ret->name = xstrndup(name, len);
 186         else
 187                 ret->name = xstrdup(name);
 188         ret->refname = xstrfmt("refs/heads/%s", ret->name);
 189
 190         return ret;
 191 }
 192
 193 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 194 {
 195         struct rewrite *ret;
 196         int i;
 197
 198         for (i = 0; i < r->rewrite_nr; i++) {
 199                 if (len
 200                     ? (len == r->rewrite[i]->baselen &&
 201                        !strncmp(base, r->rewrite[i]->base, len))
 202                     : !strcmp(base, r->rewrite[i]->base))
 203                         return r->rewrite[i];
 204         }
 205
 206         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 207         ret = xcalloc(1, sizeof(struct rewrite));
 208         r->rewrite[r->rewrite_nr++] = ret;
 209         if (len) {
 210                 ret->base = xstrndup(base, len);
 211                 ret->baselen = len;
 212         }
 213         else {
 214                 ret->base = xstrdup(base);
 215                 ret->baselen = strlen(base);
 216         }
 217         return ret;
 218 }
 219
 220 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 221 {
 222         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 223         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 224         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 225         rewrite->instead_of_nr++;
 226 }
 227
 228 static void read_remotes_file(struct remote *remote)
 229 {
 230         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 231
 232         if (!f)
 233                 return;
 234         remote->origin = REMOTE_REMOTES;
 235         while (fgets(buffer, BUF_SIZE, f)) {
 236                 int value_list;
 237                 char *s, *p;
 238
 239                 if (starts_with(buffer, "URL:")) {
 240                         value_list = 0;
 241                         s = buffer + 4;
 242                 } else if (starts_with(buffer, "Push:")) {
 243                         value_list = 1;
 244                         s = buffer + 5;
 245                 } else if (starts_with(buffer, "Pull:")) {
 246                         value_list = 2;
 247                         s = buffer + 5;
 248                 } else
 249                         continue;
 250
 251                 while (isspace(*s))
 252                         s++;
 253                 if (!*s)
 254                         continue;
 255
 256                 p = s + strlen(s);
 257                 while (isspace(p[-1]))
 258                         *--p = 0;
 259
 260                 switch (value_list) {
 261                 case 0:
 262                         add_url_alias(remote, xstrdup(s));
 263                         break;
 264                 case 1:
 265                         add_push_refspec(remote, xstrdup(s));
 266                         break;
 267                 case 2:
 268                         add_fetch_refspec(remote, xstrdup(s));
 269                         break;
 270                 }
 271         }
 272         fclose(f);
 273 }
 274
 275 static void read_branches_file(struct remote *remote)
 276 {
 277         char *frag;
 278         struct strbuf branch = STRBUF_INIT;
 279         int n = 1000;
 280         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 281         char *s, *p;
 282         int len;
 283
 284         if (!f)
 285                 return;
 286         s = fgets(buffer, BUF_SIZE, f);
 287         fclose(f);
 288         if (!s)
 289                 return;
 290         while (isspace(*s))
 291                 s++;
 292         if (!*s)
 293                 return;
 294         remote->origin = REMOTE_BRANCHES;
 295         p = s + strlen(s);
 296         while (isspace(p[-1]))
 297                 *--p = 0;
 298         len = p - s;
 299         p = xmalloc(len + 1);
 300         strcpy(p, s);
 301
 302         /*
 303          * The branches file would have URL and optionally
 304          * #branch specified.  The "master" (or specified) branch is
 305          * fetched and stored in the local branch of the same name.
 306          */
 307         frag = strchr(p, '#');
 308         if (frag) {
 309                 *(frag++) = '\0';
 310                 strbuf_addf(&branch, "refs/heads/%s", frag);
 311         } else
 312                 strbuf_addstr(&branch, "refs/heads/master");
 313
 314         strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 315         add_url_alias(remote, p);
 316         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 317         /*
 318          * Cogito compatible push: push current HEAD to remote #branch
 319          * (master if missing)
 320          */
 321         strbuf_init(&branch, 0);
 322         strbuf_addstr(&branch, "HEAD");
 323         if (frag)
 324                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 325         else
 326                 strbuf_addstr(&branch, ":refs/heads/master");
 327         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 328         remote->fetch_tags = 1; /* always auto-follow */
 329 }
 330
 331 static int handle_config(const char *key, const char *value, void *cb)
 332 {
 333         const char *name;
 334         const char *subkey;
 335         struct remote *remote;
 336         struct branch *branch;
 337         if (starts_with(key, "branch.")) {
 338                 name = key + 7;
 339                 subkey = strrchr(name, '.');
 340                 if (!subkey)
 341                         return 0;
 342                 branch = make_branch(name, subkey - name);
 343                 if (!strcmp(subkey, ".remote")) {
 344                         if (git_config_string(&branch->remote_name, key, value))
 345                                 return -1;
 346                         if (branch == current_branch) {
 347                                 default_remote_name = branch->remote_name;
 348                                 explicit_default_remote_name = 1;
 349                         }
 350                 } else if (!strcmp(subkey, ".pushremote")) {
 351                         if (branch == current_branch)
 352                                 if (git_config_string(&branch_pushremote_name, key, value))
 353                                         return -1;
 354                 } else if (!strcmp(subkey, ".merge")) {
 355                         if (!value)
 356                                 return config_error_nonbool(key);
 357                         add_merge(branch, xstrdup(value));
 358                 }
 359                 return 0;
 360         }
 361         if (starts_with(key, "url.")) {
 362                 struct rewrite *rewrite;
 363                 name = key + 4;
 364                 subkey = strrchr(name, '.');
 365                 if (!subkey)
 366                         return 0;
 367                 if (!strcmp(subkey, ".insteadof")) {
 368                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 369                         if (!value)
 370                                 return config_error_nonbool(key);
 371                         add_instead_of(rewrite, xstrdup(value));
 372                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 373                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 374                         if (!value)
 375                                 return config_error_nonbool(key);
 376                         add_instead_of(rewrite, xstrdup(value));
 377                 }
 378         }
 379
 380         if (!starts_with(key,  "remote."))
 381                 return 0;
 382         name = key + 7;
 383
 384         /* Handle remote.* variables */
 385         if (!strcmp(name, "pushdefault"))
 386                 return git_config_string(&pushremote_name, key, value);
 387
 388         /* Handle remote.<name>.* variables */
 389         if (*name == '/') {
 390                 warning("Config remote shorthand cannot begin with '/': %s",
 391                         name);
 392                 return 0;
 393         }
 394         subkey = strrchr(name, '.');
 395         if (!subkey)
 396                 return 0;
 397         remote = make_remote(name, subkey - name);
 398         remote->origin = REMOTE_CONFIG;
 399         if (!strcmp(subkey, ".mirror"))
 400                 remote->mirror = git_config_bool(key, value);
 401         else if (!strcmp(subkey, ".skipdefaultupdate"))
 402                 remote->skip_default_update = git_config_bool(key, value);
 403         else if (!strcmp(subkey, ".skipfetchall"))
 404                 remote->skip_default_update = git_config_bool(key, value);
 405         else if (!strcmp(subkey, ".prune"))
 406                 remote->prune = git_config_bool(key, value);
 407         else if (!strcmp(subkey, ".url")) {
 408                 const char *v;
 409                 if (git_config_string(&v, key, value))
 410                         return -1;
 411                 add_url(remote, v);
 412         } else if (!strcmp(subkey, ".pushurl")) {
 413                 const char *v;
 414                 if (git_config_string(&v, key, value))
 415                         return -1;
 416                 add_pushurl(remote, v);
 417         } else if (!strcmp(subkey, ".push")) {
 418                 const char *v;
 419                 if (git_config_string(&v, key, value))
 420                         return -1;
 421                 add_push_refspec(remote, v);
 422         } else if (!strcmp(subkey, ".fetch")) {
 423                 const char *v;
 424                 if (git_config_string(&v, key, value))
 425                         return -1;
 426                 add_fetch_refspec(remote, v);
 427         } else if (!strcmp(subkey, ".receivepack")) {
 428                 const char *v;
 429                 if (git_config_string(&v, key, value))
 430                         return -1;
 431                 if (!remote->receivepack)
 432                         remote->receivepack = v;
 433                 else
 434                         error("more than one receivepack given, using the first");
 435         } else if (!strcmp(subkey, ".uploadpack")) {
 436                 const char *v;
 437                 if (git_config_string(&v, key, value))
 438                         return -1;
 439                 if (!remote->uploadpack)
 440                         remote->uploadpack = v;
 441                 else
 442                         error("more than one uploadpack given, using the first");
 443         } else if (!strcmp(subkey, ".tagopt")) {
 444                 if (!strcmp(value, "--no-tags"))
 445                         remote->fetch_tags = -1;
 446                 else if (!strcmp(value, "--tags"))
 447                         remote->fetch_tags = 2;
 448         } else if (!strcmp(subkey, ".proxy")) {
 449                 return git_config_string((const char **)&remote->http_proxy,
 450                                          key, value);
 451         } else if (!strcmp(subkey, ".vcs")) {
 452                 return git_config_string(&remote->foreign_vcs, key, value);
 453         }
 454         return 0;
 455 }
 456
 457 static void alias_all_urls(void)
 458 {
 459         int i, j;
 460         for (i = 0; i < remotes_nr; i++) {
 461                 int add_pushurl_aliases;
 462                 if (!remotes[i])
 463                         continue;
 464                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 465                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 466                 }
 467                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 468                 for (j = 0; j < remotes[i]->url_nr; j++) {
 469                         if (add_pushurl_aliases)
 470                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 471                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 472                 }
 473         }
 474 }
 475
 476 static void read_config(void)
 477 {
 478         unsigned char sha1[20];
 479         const char *head_ref;
 480         int flag;
 481         if (default_remote_name) /* did this already */
 482                 return;
 483         default_remote_name = "origin";
 484         current_branch = NULL;
 485         head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 486         if (head_ref && (flag & REF_ISSYMREF) &&
 487             starts_with(head_ref, "refs/heads/")) {
 488                 current_branch =
 489                         make_branch(head_ref + strlen("refs/heads/"), 0);
 490         }
 491         git_config(handle_config, NULL);
 492         if (branch_pushremote_name) {
 493                 free((char *)pushremote_name);
 494                 pushremote_name = branch_pushremote_name;
 495         }
 496         alias_all_urls();
 497 }
 498
 499 /*
 500  * This function frees a refspec array.
 501  * Warning: code paths should be checked to ensure that the src
 502  *          and dst pointers are always freeable pointers as well
 503  *          as the refspec pointer itself.
 504  */
 505 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 506 {
 507         int i;
 508
 509         if (!refspec)
 510                 return;
 511
 512         for (i = 0; i < nr_refspec; i++) {
 513                 free(refspec[i].src);
 514                 free(refspec[i].dst);
 515         }
 516         free(refspec);
 517 }
 518
 519 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 520 {
 521         int i;
 522         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 523
 524         for (i = 0; i < nr_refspec; i++) {
 525                 size_t llen;
 526                 int is_glob;
 527                 const char *lhs, *rhs;
 528                 int flags;
 529
 530                 is_glob = 0;
 531
 532                 lhs = refspec[i];
 533                 if (*lhs == '+') {
 534                         rs[i].force = 1;
 535                         lhs++;
 536                 }
 537
 538                 rhs = strrchr(lhs, ':');
 539
 540                 /*
 541                  * Before going on, special case ":" (or "+:") as a refspec
 542                  * for pushing matching refs.
 543                  */
 544                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 545                         rs[i].matching = 1;
 546                         continue;
 547                 }
 548
 549                 if (rhs) {
 550                         size_t rlen = strlen(++rhs);
 551                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 552                         rs[i].dst = xstrndup(rhs, rlen);
 553                 }
 554
 555                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 556                 if (1 <= llen && memchr(lhs, '*', llen)) {
 557                         if ((rhs && !is_glob) || (!rhs && fetch))
 558                                 goto invalid;
 559                         is_glob = 1;
 560                 } else if (rhs && is_glob) {
 561                         goto invalid;
 562                 }
 563
 564                 rs[i].pattern = is_glob;
 565                 rs[i].src = xstrndup(lhs, llen);
 566                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 567
 568                 if (fetch) {
 569                         unsigned char unused[40];
 570
 571                         /* LHS */
 572                         if (!*rs[i].src)
 573                                 ; /* empty is ok; it means "HEAD" */
 574                         else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 575                                 rs[i].exact_sha1 = 1; /* ok */
 576                         else if (!check_refname_format(rs[i].src, flags))
 577                                 ; /* valid looking ref is ok */
 578                         else
 579                                 goto invalid;
 580                         /* RHS */
 581                         if (!rs[i].dst)
 582                                 ; /* missing is ok; it is the same as empty */
 583                         else if (!*rs[i].dst)
 584                                 ; /* empty is ok; it means "do not store" */
 585                         else if (!check_refname_format(rs[i].dst, flags))
 586                                 ; /* valid looking ref is ok */
 587                         else
 588                                 goto invalid;
 589                 } else {
 590                         /*
 591                          * LHS
 592                          * - empty is allowed; it means delete.
 593                          * - when wildcarded, it must be a valid looking ref.
 594                          * - otherwise, it must be an extended SHA-1, but
 595                          *   there is no existing way to validate this.
 596                          */
 597                         if (!*rs[i].src)
 598                                 ; /* empty is ok */
 599                         else if (is_glob) {
 600                                 if (check_refname_format(rs[i].src, flags))
 601                                         goto invalid;
 602                         }
 603                         else
 604                                 ; /* anything goes, for now */
 605                         /*
 606                          * RHS
 607                          * - missing is allowed, but LHS then must be a
 608                          *   valid looking ref.
 609                          * - empty is not allowed.
 610                          * - otherwise it must be a valid looking ref.
 611                          */
 612                         if (!rs[i].dst) {
 613                                 if (check_refname_format(rs[i].src, flags))
 614                                         goto invalid;
 615                         } else if (!*rs[i].dst) {
 616                                 goto invalid;
 617                         } else {
 618                                 if (check_refname_format(rs[i].dst, flags))
 619                                         goto invalid;
 620                         }
 621                 }
 622         }
 623         return rs;
 624
 625  invalid:
 626         if (verify) {
 627                 /*
 628                  * nr_refspec must be greater than zero and i must be valid
 629                  * since it is only possible to reach this point from within
 630                  * the for loop above.
 631                  */
 632                 free_refspecs(rs, i+1);
 633                 return NULL;
 634         }
 635         die("Invalid refspec '%s'", refspec[i]);
 636 }
 637
 638 int valid_fetch_refspec(const char *fetch_refspec_str)
 639 {
 640         struct refspec *refspec;
 641
 642         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 643         free_refspecs(refspec, 1);
 644         return !!refspec;
 645 }
 646
 647 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 648 {
 649         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 650 }
 651
 652 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 653 {
 654         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 655 }
 656
 657 void free_refspec(int nr_refspec, struct refspec *refspec)
 658 {
 659         int i;
 660         for (i = 0; i < nr_refspec; i++) {
 661                 free(refspec[i].src);
 662                 free(refspec[i].dst);
 663         }
 664         free(refspec);
 665 }
 666
 667 static int valid_remote_nick(const char *name)
 668 {
 669         if (!name[0] || is_dot_or_dotdot(name))
 670                 return 0;
 671         return !strchr(name, '/'); /* no slash */
 672 }
 673
 674 static struct remote *remote_get_1(const char *name, const char *pushremote_name)
 675 {
 676         struct remote *ret;
 677         int name_given = 0;
 678
 679         if (name)
 680                 name_given = 1;
 681         else {
 682                 if (pushremote_name) {
 683                         name = pushremote_name;
 684                         name_given = 1;
 685                 } else {
 686                         name = default_remote_name;
 687                         name_given = explicit_default_remote_name;
 688                 }
 689         }
 690
 691         ret = make_remote(name, 0);
 692         if (valid_remote_nick(name)) {
 693                 if (!valid_remote(ret))
 694                         read_remotes_file(ret);
 695                 if (!valid_remote(ret))
 696                         read_branches_file(ret);
 697         }
 698         if (name_given && !valid_remote(ret))
 699                 add_url_alias(ret, name);
 700         if (!valid_remote(ret))
 701                 return NULL;
 702         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 703         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 704         return ret;
 705 }
 706
 707 struct remote *remote_get(const char *name)
 708 {
 709         read_config();
 710         return remote_get_1(name, NULL);
 711 }
 712
 713 struct remote *pushremote_get(const char *name)
 714 {
 715         read_config();
 716         return remote_get_1(name, pushremote_name);
 717 }
 718
 719 int remote_is_configured(const char *name)
 720 {
 721         int i;
 722         read_config();
 723
 724         for (i = 0; i < remotes_nr; i++)
 725                 if (!strcmp(name, remotes[i]->name))
 726                         return 1;
 727         return 0;
 728 }
 729
 730 int for_each_remote(each_remote_fn fn, void *priv)
 731 {
 732         int i, result = 0;
 733         read_config();
 734         for (i = 0; i < remotes_nr && !result; i++) {
 735                 struct remote *r = remotes[i];
 736                 if (!r)
 737                         continue;
 738                 if (!r->fetch)
 739                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 740                                                        r->fetch_refspec);
 741                 if (!r->push)
 742                         r->push = parse_push_refspec(r->push_refspec_nr,
 743                                                      r->push_refspec);
 744                 result = fn(r, priv);
 745         }
 746         return result;
 747 }
 748
 749 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 750 {
 751         if (strcmp(ref1->name, ref2->name)) {
 752                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 753                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 754                         die(_("Cannot fetch both %s and %s to %s"),
 755                             ref1->name, ref2->name, ref2->peer_ref->name);
 756                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 757                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 758                         warning(_("%s usually tracks %s, not %s"),
 759                                 ref2->peer_ref->name, ref2->name, ref1->name);
 760                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 761                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 762                         die(_("%s tracks both %s and %s"),
 763                             ref2->peer_ref->name, ref1->name, ref2->name);
 764                 } else {
 765                         /*
 766                          * This last possibility doesn't occur because
 767                          * FETCH_HEAD_IGNORE entries always appear at
 768                          * the end of the list.
 769                          */
 770                         die(_("Internal error"));
 771                 }
 772         }
 773         free(ref2->peer_ref);
 774         free(ref2);
 775 }
 776
 777 struct ref *ref_remove_duplicates(struct ref *ref_map)
 778 {
 779         struct string_list refs = STRING_LIST_INIT_NODUP;
 780         struct ref *retval = NULL;
 781         struct ref **p = &retval;
 782
 783         while (ref_map) {
 784                 struct ref *ref = ref_map;
 785
 786                 ref_map = ref_map->next;
 787                 ref->next = NULL;
 788
 789                 if (!ref->peer_ref) {
 790                         *p = ref;
 791                         p = &ref->next;
 792                 } else {
 793                         struct string_list_item *item =
 794                                 string_list_insert(&refs, ref->peer_ref->name);
 795
 796                         if (item->util) {
 797                                 /* Entry already existed */
 798                                 handle_duplicate((struct ref *)item->util, ref);
 799                         } else {
 800                                 *p = ref;
 801                                 p = &ref->next;
 802                                 item->util = ref;
 803                         }
 804                 }
 805         }
 806
 807         string_list_clear(&refs, 0);
 808         return retval;
 809 }
 810
 811 int remote_has_url(struct remote *remote, const char *url)
 812 {
 813         int i;
 814         for (i = 0; i < remote->url_nr; i++) {
 815                 if (!strcmp(remote->url[i], url))
 816                         return 1;
 817         }
 818         return 0;
 819 }
 820
 821 static int match_name_with_pattern(const char *key, const char *name,
 822                                    const char *value, char **result)
 823 {
 824         const char *kstar = strchr(key, '*');
 825         size_t klen;
 826         size_t ksuffixlen;
 827         size_t namelen;
 828         int ret;
 829         if (!kstar)
 830                 die("Key '%s' of pattern had no '*'", key);
 831         klen = kstar - key;
 832         ksuffixlen = strlen(kstar + 1);
 833         namelen = strlen(name);
 834         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 835                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 836         if (ret && value) {
 837                 const char *vstar = strchr(value, '*');
 838                 size_t vlen;
 839                 size_t vsuffixlen;
 840                 if (!vstar)
 841                         die("Value '%s' of pattern has no '*'", value);
 842                 vlen = vstar - value;
 843                 vsuffixlen = strlen(vstar + 1);
 844                 *result = xmalloc(vlen + vsuffixlen +
 845                                   strlen(name) -
 846                                   klen - ksuffixlen + 1);
 847                 strncpy(*result, value, vlen);
 848                 strncpy(*result + vlen,
 849                         name + klen, namelen - klen - ksuffixlen);
 850                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 851                        vstar + 1);
 852         }
 853         return ret;
 854 }
 855
 856 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 857 {
 858         int i;
 859         int find_src = !query->src;
 860
 861         if (find_src && !query->dst)
 862                 error("query_refspecs_multiple: need either src or dst");
 863
 864         for (i = 0; i < ref_count; i++) {
 865                 struct refspec *refspec = &refs[i];
 866                 const char *key = find_src ? refspec->dst : refspec->src;
 867                 const char *value = find_src ? refspec->src : refspec->dst;
 868                 const char *needle = find_src ? query->dst : query->src;
 869                 char **result = find_src ? &query->src : &query->dst;
 870
 871                 if (!refspec->dst)
 872                         continue;
 873                 if (refspec->pattern) {
 874                         if (match_name_with_pattern(key, needle, value, result))
 875                                 string_list_append_nodup(results, *result);
 876                 } else if (!strcmp(needle, key)) {
 877                         string_list_append(results, value);
 878                 }
 879         }
 880 }
 881
 882 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 883 {
 884         int i;
 885         int find_src = !query->src;
 886         const char *needle = find_src ? query->dst : query->src;
 887         char **result = find_src ? &query->src : &query->dst;
 888
 889         if (find_src && !query->dst)
 890                 return error("query_refspecs: need either src or dst");
 891
 892         for (i = 0; i < ref_count; i++) {
 893                 struct refspec *refspec = &refs[i];
 894                 const char *key = find_src ? refspec->dst : refspec->src;
 895                 const char *value = find_src ? refspec->src : refspec->dst;
 896
 897                 if (!refspec->dst)
 898                         continue;
 899                 if (refspec->pattern) {
 900                         if (match_name_with_pattern(key, needle, value, result)) {
 901                                 query->force = refspec->force;
 902                                 return 0;
 903                         }
 904                 } else if (!strcmp(needle, key)) {
 905                         *result = xstrdup(value);
 906                         query->force = refspec->force;
 907                         return 0;
 908                 }
 909         }
 910         return -1;
 911 }
 912
 913 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 914                      const char *name)
 915 {
 916         struct refspec query;
 917
 918         memset(&query, 0, sizeof(struct refspec));
 919         query.src = (char *)name;
 920
 921         if (query_refspecs(refspecs, nr_refspec, &query))
 922                 return NULL;
 923
 924         return query.dst;
 925 }
 926
 927 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 928 {
 929         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 930 }
 931
 932 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 933                 const char *name)
 934 {
 935         size_t len = strlen(name);
 936         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 937         memcpy(ref->name, prefix, prefixlen);
 938         memcpy(ref->name + prefixlen, name, len);
 939         return ref;
 940 }
 941
 942 struct ref *alloc_ref(const char *name)
 943 {
 944         return alloc_ref_with_prefix("", 0, name);
 945 }
 946
 947 struct ref *copy_ref(const struct ref *ref)
 948 {
 949         struct ref *cpy;
 950         size_t len;
 951         if (!ref)
 952                 return NULL;
 953         len = strlen(ref->name);
 954         cpy = xmalloc(sizeof(struct ref) + len + 1);
 955         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 956         cpy->next = NULL;
 957         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 958         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 959         cpy->peer_ref = copy_ref(ref->peer_ref);
 960         return cpy;
 961 }
 962
 963 struct ref *copy_ref_list(const struct ref *ref)
 964 {
 965         struct ref *ret = NULL;
 966         struct ref **tail = &ret;
 967         while (ref) {
 968                 *tail = copy_ref(ref);
 969                 ref = ref->next;
 970                 tail = &((*tail)->next);
 971         }
 972         return ret;
 973 }
 974
 975 static void free_ref(struct ref *ref)
 976 {
 977         if (!ref)
 978                 return;
 979         free_ref(ref->peer_ref);
 980         free(ref->remote_status);
 981         free(ref->symref);
 982         free(ref);
 983 }
 984
 985 void free_refs(struct ref *ref)
 986 {
 987         struct ref *next;
 988         while (ref) {
 989                 next = ref->next;
 990                 free_ref(ref);
 991                 ref = next;
 992         }
 993 }
 994
 995 int ref_compare_name(const void *va, const void *vb)
 996 {
 997         const struct ref *a = va, *b = vb;
 998         return strcmp(a->name, b->name);
 999 }
1000
1001 static void *ref_list_get_next(const void *a)
1002 {
1003         return ((const struct ref *)a)->next;
1004 }
1005
1006 static void ref_list_set_next(void *a, void *next)
1007 {
1008         ((struct ref *)a)->next = next;
1009 }
1010
1011 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1012 {
1013         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1014 }
1015
1016 int count_refspec_match(const char *pattern,
1017                         struct ref *refs,
1018                         struct ref **matched_ref)
1019 {
1020         int patlen = strlen(pattern);
1021         struct ref *matched_weak = NULL;
1022         struct ref *matched = NULL;
1023         int weak_match = 0;
1024         int match = 0;
1025
1026         for (weak_match = match = 0; refs; refs = refs->next) {
1027                 char *name = refs->name;
1028                 int namelen = strlen(name);
1029
1030                 if (!refname_match(pattern, name))
1031                         continue;
1032
1033                 /* A match is "weak" if it is with refs outside
1034                  * heads or tags, and did not specify the pattern
1035                  * in full (e.g. "refs/remotes/origin/master") or at
1036                  * least from the toplevel (e.g. "remotes/origin/master");
1037                  * otherwise "git push $URL master" would result in
1038                  * ambiguity between remotes/origin/master and heads/master
1039                  * at the remote site.
1040                  */
1041                 if (namelen != patlen &&
1042                     patlen != namelen - 5 &&
1043                     !starts_with(name, "refs/heads/") &&
1044                     !starts_with(name, "refs/tags/")) {
1045                         /* We want to catch the case where only weak
1046                          * matches are found and there are multiple
1047                          * matches, and where more than one strong
1048                          * matches are found, as ambiguous.  One
1049                          * strong match with zero or more weak matches
1050                          * are acceptable as a unique match.
1051                          */
1052                         matched_weak = refs;
1053                         weak_match++;
1054                 }
1055                 else {
1056                         matched = refs;
1057                         match++;
1058                 }
1059         }
1060         if (!matched) {
1061                 if (matched_ref)
1062                         *matched_ref = matched_weak;
1063                 return weak_match;
1064         }
1065         else {
1066                 if (matched_ref)
1067                         *matched_ref = matched;
1068                 return match;
1069         }
1070 }
1071
1072 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1073 {
1074         **tail = ref;
1075         while (ref->next)
1076                 ref = ref->next;
1077         *tail = &ref->next;
1078 }
1079
1080 static struct ref *alloc_delete_ref(void)
1081 {
1082         struct ref *ref = alloc_ref("(delete)");
1083         hashclr(ref->new_sha1);
1084         return ref;
1085 }
1086
1087 static int try_explicit_object_name(const char *name,
1088                                     struct ref **match)
1089 {
1090         unsigned char sha1[20];
1091
1092         if (!*name) {
1093                 if (match)
1094                         *match = alloc_delete_ref();
1095                 return 0;
1096         }
1097
1098         if (get_sha1(name, sha1))
1099                 return -1;
1100
1101         if (match) {
1102                 *match = alloc_ref(name);
1103                 hashcpy((*match)->new_sha1, sha1);
1104         }
1105         return 0;
1106 }
1107
1108 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1109 {
1110         struct ref *ret = alloc_ref(name);
1111         tail_link_ref(ret, tail);
1112         return ret;
1113 }
1114
1115 static char *guess_ref(const char *name, struct ref *peer)
1116 {
1117         struct strbuf buf = STRBUF_INIT;
1118         unsigned char sha1[20];
1119
1120         const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1121         if (!r)
1122                 return NULL;
1123
1124         if (starts_with(r, "refs/heads/"))
1125                 strbuf_addstr(&buf, "refs/heads/");
1126         else if (starts_with(r, "refs/tags/"))
1127                 strbuf_addstr(&buf, "refs/tags/");
1128         else
1129                 return NULL;
1130
1131         strbuf_addstr(&buf, name);
1132         return strbuf_detach(&buf, NULL);
1133 }
1134
1135 static int match_explicit_lhs(struct ref *src,
1136                               struct refspec *rs,
1137                               struct ref **match,
1138                               int *allocated_match)
1139 {
1140         switch (count_refspec_match(rs->src, src, match)) {
1141         case 1:
1142                 if (allocated_match)
1143                         *allocated_match = 0;
1144                 return 0;
1145         case 0:
1146                 /* The source could be in the get_sha1() format
1147                  * not a reference name.  :refs/other is a
1148                  * way to delete 'other' ref at the remote end.
1149                  */
1150                 if (try_explicit_object_name(rs->src, match) < 0)
1151                         return error("src refspec %s does not match any.", rs->src);
1152                 if (allocated_match)
1153                         *allocated_match = 1;
1154                 return 0;
1155         default:
1156                 return error("src refspec %s matches more than one.", rs->src);
1157         }
1158 }
1159
1160 static int match_explicit(struct ref *src, struct ref *dst,
1161                           struct ref ***dst_tail,
1162                           struct refspec *rs)
1163 {
1164         struct ref *matched_src, *matched_dst;
1165         int allocated_src;
1166
1167         const char *dst_value = rs->dst;
1168         char *dst_guess;
1169
1170         if (rs->pattern || rs->matching)
1171                 return 0;
1172
1173         matched_src = matched_dst = NULL;
1174         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1175                 return -1;
1176
1177         if (!dst_value) {
1178                 unsigned char sha1[20];
1179                 int flag;
1180
1181                 dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1182                 if (!dst_value ||
1183                     ((flag & REF_ISSYMREF) &&
1184                      !starts_with(dst_value, "refs/heads/")))
1185                         die("%s cannot be resolved to branch.",
1186                             matched_src->name);
1187         }
1188
1189         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1190         case 1:
1191                 break;
1192         case 0:
1193                 if (!memcmp(dst_value, "refs/", 5))
1194                         matched_dst = make_linked_ref(dst_value, dst_tail);
1195                 else if (is_null_sha1(matched_src->new_sha1))
1196                         error("unable to delete '%s': remote ref does not exist",
1197                               dst_value);
1198                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1199                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1200                 else
1201                         error("unable to push to unqualified destination: %s\n"
1202                               "The destination refspec neither matches an "
1203                               "existing ref on the remote nor\n"
1204                               "begins with refs/, and we are unable to "
1205                               "guess a prefix based on the source ref.",
1206                               dst_value);
1207                 break;
1208         default:
1209                 matched_dst = NULL;
1210                 error("dst refspec %s matches more than one.",
1211                       dst_value);
1212                 break;
1213         }
1214         if (!matched_dst)
1215                 return -1;
1216         if (matched_dst->peer_ref)
1217                 return error("dst ref %s receives from more than one src.",
1218                       matched_dst->name);
1219         else {
1220                 matched_dst->peer_ref = allocated_src ?
1221                                         matched_src :
1222                                         copy_ref(matched_src);
1223                 matched_dst->force = rs->force;
1224         }
1225         return 0;
1226 }
1227
1228 static int match_explicit_refs(struct ref *src, struct ref *dst,
1229                                struct ref ***dst_tail, struct refspec *rs,
1230                                int rs_nr)
1231 {
1232         int i, errs;
1233         for (i = errs = 0; i < rs_nr; i++)
1234                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1235         return errs;
1236 }
1237
1238 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1239                 int send_mirror, int direction, const struct refspec **ret_pat)
1240 {
1241         const struct refspec *pat;
1242         char *name;
1243         int i;
1244         int matching_refs = -1;
1245         for (i = 0; i < rs_nr; i++) {
1246                 if (rs[i].matching &&
1247                     (matching_refs == -1 || rs[i].force)) {
1248                         matching_refs = i;
1249                         continue;
1250                 }
1251
1252                 if (rs[i].pattern) {
1253                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1254                         int match;
1255                         if (direction == FROM_SRC)
1256                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1257                         else
1258                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1259                         if (match) {
1260                                 matching_refs = i;
1261                                 break;
1262                         }
1263                 }
1264         }
1265         if (matching_refs == -1)
1266                 return NULL;
1267
1268         pat = rs + matching_refs;
1269         if (pat->matching) {
1270                 /*
1271                  * "matching refs"; traditionally we pushed everything
1272                  * including refs outside refs/heads/ hierarchy, but
1273                  * that does not make much sense these days.
1274                  */
1275                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1276                         return NULL;
1277                 name = xstrdup(ref->name);
1278         }
1279         if (ret_pat)
1280                 *ret_pat = pat;
1281         return name;
1282 }
1283
1284 static struct ref **tail_ref(struct ref **head)
1285 {
1286         struct ref **tail = head;
1287         while (*tail)
1288                 tail = &((*tail)->next);
1289         return tail;
1290 }
1291
1292 struct tips {
1293         struct commit **tip;
1294         int nr, alloc;
1295 };
1296
1297 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1298 {
1299         struct commit *commit;
1300
1301         if (is_null_sha1(sha1))
1302                 return;
1303         commit = lookup_commit_reference_gently(sha1, 1);
1304         if (!commit || (commit->object.flags & TMP_MARK))
1305                 return;
1306         commit->object.flags |= TMP_MARK;
1307         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1308         tips->tip[tips->nr++] = commit;
1309 }
1310
1311 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1312 {
1313         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1314         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1315         struct string_list_item *item;
1316         struct ref *ref;
1317         struct tips sent_tips;
1318
1319         /*
1320          * Collect everything we know they would have at the end of
1321          * this push, and collect all tags they have.
1322          */
1323         memset(&sent_tips, 0, sizeof(sent_tips));
1324         for (ref = *dst; ref; ref = ref->next) {
1325                 if (ref->peer_ref &&
1326                     !is_null_sha1(ref->peer_ref->new_sha1))
1327                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1328                 else
1329                         add_to_tips(&sent_tips, ref->old_sha1);
1330                 if (starts_with(ref->name, "refs/tags/"))
1331                         string_list_append(&dst_tag, ref->name);
1332         }
1333         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1334
1335         sort_string_list(&dst_tag);
1336
1337         /* Collect tags they do not have. */
1338         for (ref = src; ref; ref = ref->next) {
1339                 if (!starts_with(ref->name, "refs/tags/"))
1340                         continue; /* not a tag */
1341                 if (string_list_has_string(&dst_tag, ref->name))
1342                         continue; /* they already have it */
1343                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1344                         continue; /* be conservative */
1345                 item = string_list_append(&src_tag, ref->name);
1346                 item->util = ref;
1347         }
1348         string_list_clear(&dst_tag, 0);
1349
1350         /*
1351          * At this point, src_tag lists tags that are missing from
1352          * dst, and sent_tips lists the tips we are pushing or those
1353          * that we know they already have. An element in the src_tag
1354          * that is an ancestor of any of the sent_tips needs to be
1355          * sent to the other side.
1356          */
1357         if (sent_tips.nr) {
1358                 for_each_string_list_item(item, &src_tag) {
1359                         struct ref *ref = item->util;
1360                         struct ref *dst_ref;
1361                         struct commit *commit;
1362
1363                         if (is_null_sha1(ref->new_sha1))
1364                                 continue;
1365                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1366                         if (!commit)
1367                                 /* not pushing a commit, which is not an error */
1368                                 continue;
1369
1370                         /*
1371                          * Is this tag, which they do not have, reachable from
1372                          * any of the commits we are sending?
1373                          */
1374                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1375                                 continue;
1376
1377                         /* Add it in */
1378                         dst_ref = make_linked_ref(ref->name, dst_tail);
1379                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1380                         dst_ref->peer_ref = copy_ref(ref);
1381                 }
1382         }
1383         string_list_clear(&src_tag, 0);
1384         free(sent_tips.tip);
1385 }
1386
1387 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1388 {
1389         for ( ; list; list = list->next)
1390                 if (!strcmp(list->name, name))
1391                         return (struct ref *)list;
1392         return NULL;
1393 }
1394
1395 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1396 {
1397         for ( ; ref; ref = ref->next)
1398                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1399
1400         sort_string_list(ref_index);
1401 }
1402
1403 /*
1404  * Given only the set of local refs, sanity-check the set of push
1405  * refspecs. We can't catch all errors that match_push_refs would,
1406  * but we can catch some errors early before even talking to the
1407  * remote side.
1408  */
1409 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1410 {
1411         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1412         int ret = 0;
1413         int i;
1414
1415         for (i = 0; i < nr_refspec; i++) {
1416                 struct refspec *rs = refspec + i;
1417
1418                 if (rs->pattern || rs->matching)
1419                         continue;
1420
1421                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1422         }
1423
1424         free_refspec(nr_refspec, refspec);
1425         return ret;
1426 }
1427
1428 /*
1429  * Given the set of refs the local repository has, the set of refs the
1430  * remote repository has, and the refspec used for push, determine
1431  * what remote refs we will update and with what value by setting
1432  * peer_ref (which object is being pushed) and force (if the push is
1433  * forced) in elements of "dst". The function may add new elements to
1434  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1435  */
1436 int match_push_refs(struct ref *src, struct ref **dst,
1437                     int nr_refspec, const char **refspec, int flags)
1438 {
1439         struct refspec *rs;
1440         int send_all = flags & MATCH_REFS_ALL;
1441         int send_mirror = flags & MATCH_REFS_MIRROR;
1442         int send_prune = flags & MATCH_REFS_PRUNE;
1443         int errs;
1444         static const char *default_refspec[] = { ":", NULL };
1445         struct ref *ref, **dst_tail = tail_ref(dst);
1446         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1447
1448         if (!nr_refspec) {
1449                 nr_refspec = 1;
1450                 refspec = default_refspec;
1451         }
1452         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1453         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1454
1455         /* pick the remainder */
1456         for (ref = src; ref; ref = ref->next) {
1457                 struct string_list_item *dst_item;
1458                 struct ref *dst_peer;
1459                 const struct refspec *pat = NULL;
1460                 char *dst_name;
1461
1462                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1463                 if (!dst_name)
1464                         continue;
1465
1466                 if (!dst_ref_index.nr)
1467                         prepare_ref_index(&dst_ref_index, *dst);
1468
1469                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1470                 dst_peer = dst_item ? dst_item->util : NULL;
1471                 if (dst_peer) {
1472                         if (dst_peer->peer_ref)
1473                                 /* We're already sending something to this ref. */
1474                                 goto free_name;
1475                 } else {
1476                         if (pat->matching && !(send_all || send_mirror))
1477                                 /*
1478                                  * Remote doesn't have it, and we have no
1479                                  * explicit pattern, and we don't have
1480                                  * --all or --mirror.
1481                                  */
1482                                 goto free_name;
1483
1484                         /* Create a new one and link it */
1485                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1486                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1487                         string_list_insert(&dst_ref_index,
1488                                 dst_peer->name)->util = dst_peer;
1489                 }
1490                 dst_peer->peer_ref = copy_ref(ref);
1491                 dst_peer->force = pat->force;
1492         free_name:
1493                 free(dst_name);
1494         }
1495
1496         string_list_clear(&dst_ref_index, 0);
1497
1498         if (flags & MATCH_REFS_FOLLOW_TAGS)
1499                 add_missing_tags(src, dst, &dst_tail);
1500
1501         if (send_prune) {
1502                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1503                 /* check for missing refs on the remote */
1504                 for (ref = *dst; ref; ref = ref->next) {
1505                         char *src_name;
1506
1507                         if (ref->peer_ref)
1508                                 /* We're already sending something to this ref. */
1509                                 continue;
1510
1511                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1512                         if (src_name) {
1513                                 if (!src_ref_index.nr)
1514                                         prepare_ref_index(&src_ref_index, src);
1515                                 if (!string_list_has_string(&src_ref_index,
1516                                             src_name))
1517                                         ref->peer_ref = alloc_delete_ref();
1518                                 free(src_name);
1519                         }
1520                 }
1521                 string_list_clear(&src_ref_index, 0);
1522         }
1523         if (errs)
1524                 return -1;
1525         return 0;
1526 }
1527
1528 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1529                              int force_update)
1530 {
1531         struct ref *ref;
1532
1533         for (ref = remote_refs; ref; ref = ref->next) {
1534                 int force_ref_update = ref->force || force_update;
1535                 int reject_reason = 0;
1536
1537                 if (ref->peer_ref)
1538                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1539                 else if (!send_mirror)
1540                         continue;
1541
1542                 ref->deletion = is_null_sha1(ref->new_sha1);
1543                 if (!ref->deletion &&
1544                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1545                         ref->status = REF_STATUS_UPTODATE;
1546                         continue;
1547                 }
1548
1549                 /*
1550                  * Bypass the usual "must fast-forward" check but
1551                  * replace it with a weaker "the old value must be
1552                  * this value we observed".  If the remote ref has
1553                  * moved and is now different from what we expect,
1554                  * reject any push.
1555                  *
1556                  * It also is an error if the user told us to check
1557                  * with the remote-tracking branch to find the value
1558                  * to expect, but we did not have such a tracking
1559                  * branch.
1560                  */
1561                 if (ref->expect_old_sha1) {
1562                         if (ref->expect_old_no_trackback ||
1563                             hashcmp(ref->old_sha1, ref->old_sha1_expect))
1564                                 reject_reason = REF_STATUS_REJECT_STALE;
1565                 }
1566
1567                 /*
1568                  * The usual "must fast-forward" rules.
1569                  *
1570                  * Decide whether an individual refspec A:B can be
1571                  * pushed.  The push will succeed if any of the
1572                  * following are true:
1573                  *
1574                  * (1) the remote reference B does not exist
1575                  *
1576                  * (2) the remote reference B is being removed (i.e.,
1577                  *     pushing :B where no source is specified)
1578                  *
1579                  * (3) the destination is not under refs/tags/, and
1580                  *     if the old and new value is a commit, the new
1581                  *     is a descendant of the old.
1582                  *
1583                  * (4) it is forced using the +A:B notation, or by
1584                  *     passing the --force argument
1585                  */
1586
1587                 else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1588                         if (starts_with(ref->name, "refs/tags/"))
1589                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1590                         else if (!has_sha1_file(ref->old_sha1))
1591                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1592                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1593                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1594                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1595                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1596                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1597                 }
1598
1599                 /*
1600                  * "--force" will defeat any rejection implemented
1601                  * by the rules above.
1602                  */
1603                 if (!force_ref_update)
1604                         ref->status = reject_reason;
1605                 else if (reject_reason)
1606                         ref->forced_update = 1;
1607         }
1608 }
1609
1610 struct branch *branch_get(const char *name)
1611 {
1612         struct branch *ret;
1613
1614         read_config();
1615         if (!name || !*name || !strcmp(name, "HEAD"))
1616                 ret = current_branch;
1617         else
1618                 ret = make_branch(name, 0);
1619         if (ret && ret->remote_name) {
1620                 ret->remote = remote_get(ret->remote_name);
1621                 if (ret->merge_nr) {
1622                         int i;
1623                         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1624                         for (i = 0; i < ret->merge_nr; i++) {
1625                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1626                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1627                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1628                                     && !strcmp(ret->remote_name, "."))
1629                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1630                         }
1631                 }
1632         }
1633         return ret;
1634 }
1635
1636 int branch_has_merge_config(struct branch *branch)
1637 {
1638         return branch && !!branch->merge;
1639 }
1640
1641 int branch_merge_matches(struct branch *branch,
1642                                  int i,
1643                                  const char *refname)
1644 {
1645         if (!branch || i < 0 || i >= branch->merge_nr)
1646                 return 0;
1647         return refname_match(branch->merge[i]->src, refname);
1648 }
1649
1650 static int ignore_symref_update(const char *refname)
1651 {
1652         unsigned char sha1[20];
1653         int flag;
1654
1655         if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1656                 return 0; /* non-existing refs are OK */
1657         return (flag & REF_ISSYMREF);
1658 }
1659
1660 /*
1661  * Create and return a list of (struct ref) consisting of copies of
1662  * each remote_ref that matches refspec.  refspec must be a pattern.
1663  * Fill in the copies' peer_ref to describe the local tracking refs to
1664  * which they map.  Omit any references that would map to an existing
1665  * local symbolic ref.
1666  */
1667 static struct ref *get_expanded_map(const struct ref *remote_refs,
1668                                     const struct refspec *refspec)
1669 {
1670         const struct ref *ref;
1671         struct ref *ret = NULL;
1672         struct ref **tail = &ret;
1673
1674         for (ref = remote_refs; ref; ref = ref->next) {
1675                 char *expn_name = NULL;
1676
1677                 if (strchr(ref->name, '^'))
1678                         continue; /* a dereference item */
1679                 if (match_name_with_pattern(refspec->src, ref->name,
1680                                             refspec->dst, &expn_name) &&
1681                     !ignore_symref_update(expn_name)) {
1682                         struct ref *cpy = copy_ref(ref);
1683
1684                         cpy->peer_ref = alloc_ref(expn_name);
1685                         if (refspec->force)
1686                                 cpy->peer_ref->force = 1;
1687                         *tail = cpy;
1688                         tail = &cpy->next;
1689                 }
1690                 free(expn_name);
1691         }
1692
1693         return ret;
1694 }
1695
1696 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1697 {
1698         const struct ref *ref;
1699         for (ref = refs; ref; ref = ref->next) {
1700                 if (refname_match(name, ref->name))
1701                         return ref;
1702         }
1703         return NULL;
1704 }
1705
1706 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1707 {
1708         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1709
1710         if (!ref)
1711                 return NULL;
1712
1713         return copy_ref(ref);
1714 }
1715
1716 static struct ref *get_local_ref(const char *name)
1717 {
1718         if (!name || name[0] == '\0')
1719                 return NULL;
1720
1721         if (starts_with(name, "refs/"))
1722                 return alloc_ref(name);
1723
1724         if (starts_with(name, "heads/") ||
1725             starts_with(name, "tags/") ||
1726             starts_with(name, "remotes/"))
1727                 return alloc_ref_with_prefix("refs/", 5, name);
1728
1729         return alloc_ref_with_prefix("refs/heads/", 11, name);
1730 }
1731
1732 int get_fetch_map(const struct ref *remote_refs,
1733                   const struct refspec *refspec,
1734                   struct ref ***tail,
1735                   int missing_ok)
1736 {
1737         struct ref *ref_map, **rmp;
1738
1739         if (refspec->pattern) {
1740                 ref_map = get_expanded_map(remote_refs, refspec);
1741         } else {
1742                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1743
1744                 if (refspec->exact_sha1) {
1745                         ref_map = alloc_ref(name);
1746                         get_sha1_hex(name, ref_map->old_sha1);
1747                 } else {
1748                         ref_map = get_remote_ref(remote_refs, name);
1749                 }
1750                 if (!missing_ok && !ref_map)
1751                         die("Couldn't find remote ref %s", name);
1752                 if (ref_map) {
1753                         ref_map->peer_ref = get_local_ref(refspec->dst);
1754                         if (ref_map->peer_ref && refspec->force)
1755                                 ref_map->peer_ref->force = 1;
1756                 }
1757         }
1758
1759         for (rmp = &ref_map; *rmp; ) {
1760                 if ((*rmp)->peer_ref) {
1761                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1762                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1763                                 struct ref *ignore = *rmp;
1764                                 error("* Ignoring funny ref '%s' locally",
1765                                       (*rmp)->peer_ref->name);
1766                                 *rmp = (*rmp)->next;
1767                                 free(ignore->peer_ref);
1768                                 free(ignore);
1769                                 continue;
1770                         }
1771                 }
1772                 rmp = &((*rmp)->next);
1773         }
1774
1775         if (ref_map)
1776                 tail_link_ref(ref_map, tail);
1777
1778         return 0;
1779 }
1780
1781 int resolve_remote_symref(struct ref *ref, struct ref *list)
1782 {
1783         if (!ref->symref)
1784                 return 0;
1785         for (; list; list = list->next)
1786                 if (!strcmp(ref->symref, list->name)) {
1787                         hashcpy(ref->old_sha1, list->old_sha1);
1788                         return 0;
1789                 }
1790         return 1;
1791 }
1792
1793 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1794 {
1795         while (list) {
1796                 struct commit_list *temp = list;
1797                 temp->item->object.flags &= ~mark;
1798                 list = temp->next;
1799                 free(temp);
1800         }
1801 }
1802
1803 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1804 {
1805         struct object *o;
1806         struct commit *old, *new;
1807         struct commit_list *list, *used;
1808         int found = 0;
1809
1810         /*
1811          * Both new and old must be commit-ish and new is descendant of
1812          * old.  Otherwise we require --force.
1813          */
1814         o = deref_tag(parse_object(old_sha1), NULL, 0);
1815         if (!o || o->type != OBJ_COMMIT)
1816                 return 0;
1817         old = (struct commit *) o;
1818
1819         o = deref_tag(parse_object(new_sha1), NULL, 0);
1820         if (!o || o->type != OBJ_COMMIT)
1821                 return 0;
1822         new = (struct commit *) o;
1823
1824         if (parse_commit(new) < 0)
1825                 return 0;
1826
1827         used = list = NULL;
1828         commit_list_insert(new, &list);
1829         while (list) {
1830                 new = pop_most_recent_commit(&list, TMP_MARK);
1831                 commit_list_insert(new, &used);
1832                 if (new == old) {
1833                         found = 1;
1834                         break;
1835                 }
1836         }
1837         unmark_and_free(list, TMP_MARK);
1838         unmark_and_free(used, TMP_MARK);
1839         return found;
1840 }
1841
1842 /*
1843  * Compare a branch with its upstream, and save their differences (number
1844  * of commits) in *num_ours and *num_theirs.
1845  *
1846  * Return 0 if branch has no upstream (no base), -1 if upstream is missing
1847  * (with "gone" base), otherwise 1 (with base).
1848  */
1849 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1850 {
1851         unsigned char sha1[20];
1852         struct commit *ours, *theirs;
1853         char symmetric[84];
1854         struct rev_info revs;
1855         const char *rev_argv[10], *base;
1856         int rev_argc;
1857
1858         /* Cannot stat unless we are marked to build on top of somebody else. */
1859         if (!branch ||
1860             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1861                 return 0;
1862
1863         /* Cannot stat if what we used to build on no longer exists */
1864         base = branch->merge[0]->dst;
1865         if (read_ref(base, sha1))
1866                 return -1;
1867         theirs = lookup_commit_reference(sha1);
1868         if (!theirs)
1869                 return -1;
1870
1871         if (read_ref(branch->refname, sha1))
1872                 return -1;
1873         ours = lookup_commit_reference(sha1);
1874         if (!ours)
1875                 return -1;
1876
1877         /* are we the same? */
1878         if (theirs == ours) {
1879                 *num_theirs = *num_ours = 0;
1880                 return 1;
1881         }
1882
1883         /* Run "rev-list --left-right ours...theirs" internally... */
1884         rev_argc = 0;
1885         rev_argv[rev_argc++] = NULL;
1886         rev_argv[rev_argc++] = "--left-right";
1887         rev_argv[rev_argc++] = symmetric;
1888         rev_argv[rev_argc++] = "--";
1889         rev_argv[rev_argc] = NULL;
1890
1891         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1892         strcpy(symmetric + 40, "...");
1893         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1894
1895         init_revisions(&revs, NULL);
1896         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1897         prepare_revision_walk(&revs);
1898
1899         /* ... and count the commits on each side. */
1900         *num_ours = 0;
1901         *num_theirs = 0;
1902         while (1) {
1903                 struct commit *c = get_revision(&revs);
1904                 if (!c)
1905                         break;
1906                 if (c->object.flags & SYMMETRIC_LEFT)
1907                         (*num_ours)++;
1908                 else
1909                         (*num_theirs)++;
1910         }
1911
1912         /* clear object flags smudged by the above traversal */
1913         clear_commit_marks(ours, ALL_REV_FLAGS);
1914         clear_commit_marks(theirs, ALL_REV_FLAGS);
1915         return 1;
1916 }
1917
1918 /*
1919  * Return true when there is anything to report, otherwise false.
1920  */
1921 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1922 {
1923         int ours, theirs;
1924         const char *base;
1925         int upstream_is_gone = 0;
1926
1927         switch (stat_tracking_info(branch, &ours, &theirs)) {
1928         case 0:
1929                 /* no base */
1930                 return 0;
1931         case -1:
1932                 /* with "gone" base */
1933                 upstream_is_gone = 1;
1934                 break;
1935         default:
1936                 /* with base */
1937                 break;
1938         }
1939
1940         base = branch->merge[0]->dst;
1941         base = shorten_unambiguous_ref(base, 0);
1942         if (upstream_is_gone) {
1943                 strbuf_addf(sb,
1944                         _("Your branch is based on '%s', but the upstream is gone.\n"),
1945                         base);
1946                 if (advice_status_hints)
1947                         strbuf_addf(sb,
1948                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1949         } else if (!ours && !theirs) {
1950                 strbuf_addf(sb,
1951                         _("Your branch is up-to-date with '%s'.\n"),
1952                         base);
1953         } else if (!theirs) {
1954                 strbuf_addf(sb,
1955                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1956                            "Your branch is ahead of '%s' by %d commits.\n",
1957                            ours),
1958                         base, ours);
1959                 if (advice_status_hints)
1960                         strbuf_addf(sb,
1961                                 _("  (use \"git push\" to publish your local commits)\n"));
1962         } else if (!ours) {
1963                 strbuf_addf(sb,
1964                         Q_("Your branch is behind '%s' by %d commit, "
1965                                "and can be fast-forwarded.\n",
1966                            "Your branch is behind '%s' by %d commits, "
1967                                "and can be fast-forwarded.\n",
1968                            theirs),
1969                         base, theirs);
1970                 if (advice_status_hints)
1971                         strbuf_addf(sb,
1972                                 _("  (use \"git pull\" to update your local branch)\n"));
1973         } else {
1974                 strbuf_addf(sb,
1975                         Q_("Your branch and '%s' have diverged,\n"
1976                                "and have %d and %d different commit each, "
1977                                "respectively.\n",
1978                            "Your branch and '%s' have diverged,\n"
1979                                "and have %d and %d different commits each, "
1980                                "respectively.\n",
1981                            theirs),
1982                         base, ours, theirs);
1983                 if (advice_status_hints)
1984                         strbuf_addf(sb,
1985                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1986         }
1987         return 1;
1988 }
1989
1990 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1991 {
1992         struct ref ***local_tail = cb_data;
1993         struct ref *ref;
1994         int len;
1995
1996         /* we already know it starts with refs/ to get here */
1997         if (check_refname_format(refname + 5, 0))
1998                 return 0;
1999
2000         len = strlen(refname) + 1;
2001         ref = xcalloc(1, sizeof(*ref) + len);
2002         hashcpy(ref->new_sha1, sha1);
2003         memcpy(ref->name, refname, len);
2004         **local_tail = ref;
2005         *local_tail = &ref->next;
2006         return 0;
2007 }
2008
2009 struct ref *get_local_heads(void)
2010 {
2011         struct ref *local_refs = NULL, **local_tail = &local_refs;
2012         for_each_ref(one_local_ref, &local_tail);
2013         return local_refs;
2014 }
2015
2016 struct ref *guess_remote_head(const struct ref *head,
2017                               const struct ref *refs,
2018                               int all)
2019 {
2020         const struct ref *r;
2021         struct ref *list = NULL;
2022         struct ref **tail = &list;
2023
2024         if (!head)
2025                 return NULL;
2026
2027         /*
2028          * Some transports support directly peeking at
2029          * where HEAD points; if that is the case, then
2030          * we don't have to guess.
2031          */
2032         if (head->symref)
2033                 return copy_ref(find_ref_by_name(refs, head->symref));
2034
2035         /* If refs/heads/master could be right, it is. */
2036         if (!all) {
2037                 r = find_ref_by_name(refs, "refs/heads/master");
2038                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
2039                         return copy_ref(r);
2040         }
2041
2042         /* Look for another ref that points there */
2043         for (r = refs; r; r = r->next) {
2044                 if (r != head &&
2045                     starts_with(r->name, "refs/heads/") &&
2046                     !hashcmp(r->old_sha1, head->old_sha1)) {
2047                         *tail = copy_ref(r);
2048                         tail = &((*tail)->next);
2049                         if (!all)
2050                                 break;
2051                 }
2052         }
2053
2054         return list;
2055 }
2056
2057 struct stale_heads_info {
2058         struct string_list *ref_names;
2059         struct ref **stale_refs_tail;
2060         struct refspec *refs;
2061         int ref_count;
2062 };
2063
2064 static int get_stale_heads_cb(const char *refname,
2065         const unsigned char *sha1, int flags, void *cb_data)
2066 {
2067         struct stale_heads_info *info = cb_data;
2068         struct string_list matches = STRING_LIST_INIT_DUP;
2069         struct refspec query;
2070         int i, stale = 1;
2071         memset(&query, 0, sizeof(struct refspec));
2072         query.dst = (char *)refname;
2073
2074         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2075         if (matches.nr == 0)
2076                 goto clean_exit; /* No matches */
2077
2078         /*
2079          * If we did find a suitable refspec and it's not a symref and
2080          * it's not in the list of refs that currently exist in that
2081          * remote, we consider it to be stale. In order to deal with
2082          * overlapping refspecs, we need to go over all of the
2083          * matching refs.
2084          */
2085         if (flags & REF_ISSYMREF)
2086                 goto clean_exit;
2087
2088         for (i = 0; stale && i < matches.nr; i++)
2089                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2090                         stale = 0;
2091
2092         if (stale) {
2093                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2094                 hashcpy(ref->new_sha1, sha1);
2095         }
2096
2097 clean_exit:
2098         string_list_clear(&matches, 0);
2099         return 0;
2100 }
2101
2102 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2103 {
2104         struct ref *ref, *stale_refs = NULL;
2105         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2106         struct stale_heads_info info;
2107         info.ref_names = &ref_names;
2108         info.stale_refs_tail = &stale_refs;
2109         info.refs = refs;
2110         info.ref_count = ref_count;
2111         for (ref = fetch_map; ref; ref = ref->next)
2112                 string_list_append(&ref_names, ref->name);
2113         sort_string_list(&ref_names);
2114         for_each_ref(get_stale_heads_cb, &info);
2115         string_list_clear(&ref_names, 0);
2116         return stale_refs;
2117 }
2118
2119 /*
2120  * Compare-and-swap
2121  */
2122 void clear_cas_option(struct push_cas_option *cas)
2123 {
2124         int i;
2125
2126         for (i = 0; i < cas->nr; i++)
2127                 free(cas->entry[i].refname);
2128         free(cas->entry);
2129         memset(cas, 0, sizeof(*cas));
2130 }
2131
2132 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2133                                       const char *refname,
2134                                       size_t refnamelen)
2135 {
2136         struct push_cas *entry;
2137         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2138         entry = &cas->entry[cas->nr++];
2139         memset(entry, 0, sizeof(*entry));
2140         entry->refname = xmemdupz(refname, refnamelen);
2141         return entry;
2142 }
2143
2144 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2145 {
2146         const char *colon;
2147         struct push_cas *entry;
2148
2149         if (unset) {
2150                 /* "--no-<option>" */
2151                 clear_cas_option(cas);
2152                 return 0;
2153         }
2154
2155         if (!arg) {
2156                 /* just "--<option>" */
2157                 cas->use_tracking_for_rest = 1;
2158                 return 0;
2159         }
2160
2161         /* "--<option>=refname" or "--<option>=refname:value" */
2162         colon = strchrnul(arg, ':');
2163         entry = add_cas_entry(cas, arg, colon - arg);
2164         if (!*colon)
2165                 entry->use_tracking = 1;
2166         else if (get_sha1(colon + 1, entry->expect))
2167                 return error("cannot parse expected object name '%s'", colon + 1);
2168         return 0;
2169 }
2170
2171 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2172 {
2173         return parse_push_cas_option(opt->value, arg, unset);
2174 }
2175
2176 int is_empty_cas(const struct push_cas_option *cas)
2177 {
2178         return !cas->use_tracking_for_rest && !cas->nr;
2179 }
2180
2181 /*
2182  * Look at remote.fetch refspec and see if we have a remote
2183  * tracking branch for the refname there.  Fill its current
2184  * value in sha1[].
2185  * If we cannot do so, return negative to signal an error.
2186  */
2187 static int remote_tracking(struct remote *remote, const char *refname,
2188                            unsigned char sha1[20])
2189 {
2190         char *dst;
2191
2192         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2193         if (!dst)
2194                 return -1; /* no tracking ref for refname at remote */
2195         if (read_ref(dst, sha1))
2196                 return -1; /* we know what the tracking ref is but we cannot read it */
2197         return 0;
2198 }
2199
2200 static void apply_cas(struct push_cas_option *cas,
2201                       struct remote *remote,
2202                       struct ref *ref)
2203 {
2204         int i;
2205
2206         /* Find an explicit --<option>=<name>[:<value>] entry */
2207         for (i = 0; i < cas->nr; i++) {
2208                 struct push_cas *entry = &cas->entry[i];
2209                 if (!refname_match(entry->refname, ref->name))
2210                         continue;
2211                 ref->expect_old_sha1 = 1;
2212                 if (!entry->use_tracking)
2213                         hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2214                 else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2215                         ref->expect_old_no_trackback = 1;
2216                 return;
2217         }
2218
2219         /* Are we using "--<option>" to cover all? */
2220         if (!cas->use_tracking_for_rest)
2221                 return;
2222
2223         ref->expect_old_sha1 = 1;
2224         if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2225                 ref->expect_old_no_trackback = 1;
2226 }
2227
2228 void apply_push_cas(struct push_cas_option *cas,
2229                     struct remote *remote,
2230                     struct ref *remote_refs)
2231 {
2232         struct ref *ref;
2233         for (ref = remote_refs; ref; ref = ref->next)
2234                 apply_cas(cas, remote, ref);
2235 }