remote.con commit Merge branch 'maint' (9d52f15)
   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
  11static struct refspec s_tag_refspec = {
  12        0,
  13        1,
  14        0,
  15        "refs/tags/*",
  16        "refs/tags/*"
  17};
  18
  19const struct refspec *tag_refspec = &s_tag_refspec;
  20
  21struct counted_string {
  22        size_t len;
  23        const char *s;
  24};
  25struct rewrite {
  26        const char *base;
  27        size_t baselen;
  28        struct counted_string *instead_of;
  29        int instead_of_nr;
  30        int instead_of_alloc;
  31};
  32struct rewrites {
  33        struct rewrite **rewrite;
  34        int rewrite_alloc;
  35        int rewrite_nr;
  36};
  37
  38static struct remote **remotes;
  39static int remotes_alloc;
  40static int remotes_nr;
  41
  42static struct branch **branches;
  43static int branches_alloc;
  44static int branches_nr;
  45
  46static struct branch *current_branch;
  47static const char *default_remote_name;
  48static int explicit_default_remote_name;
  49
  50static struct rewrites rewrites;
  51static struct rewrites rewrites_push;
  52
  53#define BUF_SIZE (2048)
  54static char buffer[BUF_SIZE];
  55
  56static int valid_remote(const struct remote *remote)
  57{
  58        return (!!remote->url) || (!!remote->foreign_vcs);
  59}
  60
  61static const char *alias_url(const char *url, struct rewrites *r)
  62{
  63        int i, j;
  64        char *ret;
  65        struct counted_string *longest;
  66        int longest_i;
  67
  68        longest = NULL;
  69        longest_i = -1;
  70        for (i = 0; i < r->rewrite_nr; i++) {
  71                if (!r->rewrite[i])
  72                        continue;
  73                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  74                        if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  75                            (!longest ||
  76                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  77                                longest = &(r->rewrite[i]->instead_of[j]);
  78                                longest_i = i;
  79                        }
  80                }
  81        }
  82        if (!longest)
  83                return url;
  84
  85        ret = xmalloc(r->rewrite[longest_i]->baselen +
  86                     (strlen(url) - longest->len) + 1);
  87        strcpy(ret, r->rewrite[longest_i]->base);
  88        strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  89        return ret;
  90}
  91
  92static void add_push_refspec(struct remote *remote, const char *ref)
  93{
  94        ALLOC_GROW(remote->push_refspec,
  95                   remote->push_refspec_nr + 1,
  96                   remote->push_refspec_alloc);
  97        remote->push_refspec[remote->push_refspec_nr++] = ref;
  98}
  99
 100static void add_fetch_refspec(struct remote *remote, const char *ref)
 101{
 102        ALLOC_GROW(remote->fetch_refspec,
 103                   remote->fetch_refspec_nr + 1,
 104                   remote->fetch_refspec_alloc);
 105        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 106}
 107
 108static void add_url(struct remote *remote, const char *url)
 109{
 110        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 111        remote->url[remote->url_nr++] = url;
 112}
 113
 114static void add_pushurl(struct remote *remote, const char *pushurl)
 115{
 116        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 117        remote->pushurl[remote->pushurl_nr++] = pushurl;
 118}
 119
 120static void add_pushurl_alias(struct remote *remote, const char *url)
 121{
 122        const char *pushurl = alias_url(url, &rewrites_push);
 123        if (pushurl != url)
 124                add_pushurl(remote, pushurl);
 125}
 126
 127static void add_url_alias(struct remote *remote, const char *url)
 128{
 129        add_url(remote, alias_url(url, &rewrites));
 130        add_pushurl_alias(remote, url);
 131}
 132
 133static struct remote *make_remote(const char *name, int len)
 134{
 135        struct remote *ret;
 136        int i;
 137
 138        for (i = 0; i < remotes_nr; i++) {
 139                if (len ? (!strncmp(name, remotes[i]->name, len) &&
 140                           !remotes[i]->name[len]) :
 141                    !strcmp(name, remotes[i]->name))
 142                        return remotes[i];
 143        }
 144
 145        ret = xcalloc(1, sizeof(struct remote));
 146        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 147        remotes[remotes_nr++] = ret;
 148        if (len)
 149                ret->name = xstrndup(name, len);
 150        else
 151                ret->name = xstrdup(name);
 152        return ret;
 153}
 154
 155static void add_merge(struct branch *branch, const char *name)
 156{
 157        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 158                   branch->merge_alloc);
 159        branch->merge_name[branch->merge_nr++] = name;
 160}
 161
 162static struct branch *make_branch(const char *name, int len)
 163{
 164        struct branch *ret;
 165        int i;
 166        char *refname;
 167
 168        for (i = 0; i < branches_nr; i++) {
 169                if (len ? (!strncmp(name, branches[i]->name, len) &&
 170                           !branches[i]->name[len]) :
 171                    !strcmp(name, branches[i]->name))
 172                        return branches[i];
 173        }
 174
 175        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 176        ret = xcalloc(1, sizeof(struct branch));
 177        branches[branches_nr++] = ret;
 178        if (len)
 179                ret->name = xstrndup(name, len);
 180        else
 181                ret->name = xstrdup(name);
 182        refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 183        strcpy(refname, "refs/heads/");
 184        strcpy(refname + strlen("refs/heads/"), ret->name);
 185        ret->refname = refname;
 186
 187        return ret;
 188}
 189
 190static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 191{
 192        struct rewrite *ret;
 193        int i;
 194
 195        for (i = 0; i < r->rewrite_nr; i++) {
 196                if (len
 197                    ? (len == r->rewrite[i]->baselen &&
 198                       !strncmp(base, r->rewrite[i]->base, len))
 199                    : !strcmp(base, r->rewrite[i]->base))
 200                        return r->rewrite[i];
 201        }
 202
 203        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 204        ret = xcalloc(1, sizeof(struct rewrite));
 205        r->rewrite[r->rewrite_nr++] = ret;
 206        if (len) {
 207                ret->base = xstrndup(base, len);
 208                ret->baselen = len;
 209        }
 210        else {
 211                ret->base = xstrdup(base);
 212                ret->baselen = strlen(base);
 213        }
 214        return ret;
 215}
 216
 217static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 218{
 219        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 220        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 221        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 222        rewrite->instead_of_nr++;
 223}
 224
 225static void read_remotes_file(struct remote *remote)
 226{
 227        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 228
 229        if (!f)
 230                return;
 231        remote->origin = REMOTE_REMOTES;
 232        while (fgets(buffer, BUF_SIZE, f)) {
 233                int value_list;
 234                char *s, *p;
 235
 236                if (!prefixcmp(buffer, "URL:")) {
 237                        value_list = 0;
 238                        s = buffer + 4;
 239                } else if (!prefixcmp(buffer, "Push:")) {
 240                        value_list = 1;
 241                        s = buffer + 5;
 242                } else if (!prefixcmp(buffer, "Pull:")) {
 243                        value_list = 2;
 244                        s = buffer + 5;
 245                } else
 246                        continue;
 247
 248                while (isspace(*s))
 249                        s++;
 250                if (!*s)
 251                        continue;
 252
 253                p = s + strlen(s);
 254                while (isspace(p[-1]))
 255                        *--p = 0;
 256
 257                switch (value_list) {
 258                case 0:
 259                        add_url_alias(remote, xstrdup(s));
 260                        break;
 261                case 1:
 262                        add_push_refspec(remote, xstrdup(s));
 263                        break;
 264                case 2:
 265                        add_fetch_refspec(remote, xstrdup(s));
 266                        break;
 267                }
 268        }
 269        fclose(f);
 270}
 271
 272static void read_branches_file(struct remote *remote)
 273{
 274        const char *slash = strchr(remote->name, '/');
 275        char *frag;
 276        struct strbuf branch = STRBUF_INIT;
 277        int n = slash ? slash - remote->name : 1000;
 278        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 279        char *s, *p;
 280        int len;
 281
 282        if (!f)
 283                return;
 284        s = fgets(buffer, BUF_SIZE, f);
 285        fclose(f);
 286        if (!s)
 287                return;
 288        while (isspace(*s))
 289                s++;
 290        if (!*s)
 291                return;
 292        remote->origin = REMOTE_BRANCHES;
 293        p = s + strlen(s);
 294        while (isspace(p[-1]))
 295                *--p = 0;
 296        len = p - s;
 297        if (slash)
 298                len += strlen(slash);
 299        p = xmalloc(len + 1);
 300        strcpy(p, s);
 301        if (slash)
 302                strcat(p, slash);
 303
 304        /*
 305         * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 306         * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 307         * the partial URL obtained from the branches file plus
 308         * "/netdev-2.6" and does not store it in any tracking ref.
 309         * #branch specifier in the file is ignored.
 310         *
 311         * Otherwise, the branches file would have URL and optionally
 312         * #branch specified.  The "master" (or specified) branch is
 313         * fetched and stored in the local branch of the same name.
 314         */
 315        frag = strchr(p, '#');
 316        if (frag) {
 317                *(frag++) = '\0';
 318                strbuf_addf(&branch, "refs/heads/%s", frag);
 319        } else
 320                strbuf_addstr(&branch, "refs/heads/master");
 321        if (!slash) {
 322                strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 323        } else {
 324                strbuf_reset(&branch);
 325                strbuf_addstr(&branch, "HEAD:");
 326        }
 327        add_url_alias(remote, p);
 328        add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 329        /*
 330         * Cogito compatible push: push current HEAD to remote #branch
 331         * (master if missing)
 332         */
 333        strbuf_init(&branch, 0);
 334        strbuf_addstr(&branch, "HEAD");
 335        if (frag)
 336                strbuf_addf(&branch, ":refs/heads/%s", frag);
 337        else
 338                strbuf_addstr(&branch, ":refs/heads/master");
 339        add_push_refspec(remote, strbuf_detach(&branch, NULL));
 340        remote->fetch_tags = 1; /* always auto-follow */
 341}
 342
 343static int handle_config(const char *key, const char *value, void *cb)
 344{
 345        const char *name;
 346        const char *subkey;
 347        struct remote *remote;
 348        struct branch *branch;
 349        if (!prefixcmp(key, "branch.")) {
 350                name = key + 7;
 351                subkey = strrchr(name, '.');
 352                if (!subkey)
 353                        return 0;
 354                branch = make_branch(name, subkey - name);
 355                if (!strcmp(subkey, ".remote")) {
 356                        if (!value)
 357                                return config_error_nonbool(key);
 358                        branch->remote_name = xstrdup(value);
 359                        if (branch == current_branch) {
 360                                default_remote_name = branch->remote_name;
 361                                explicit_default_remote_name = 1;
 362                        }
 363                } else if (!strcmp(subkey, ".merge")) {
 364                        if (!value)
 365                                return config_error_nonbool(key);
 366                        add_merge(branch, xstrdup(value));
 367                }
 368                return 0;
 369        }
 370        if (!prefixcmp(key, "url.")) {
 371                struct rewrite *rewrite;
 372                name = key + 4;
 373                subkey = strrchr(name, '.');
 374                if (!subkey)
 375                        return 0;
 376                if (!strcmp(subkey, ".insteadof")) {
 377                        rewrite = make_rewrite(&rewrites, name, subkey - name);
 378                        if (!value)
 379                                return config_error_nonbool(key);
 380                        add_instead_of(rewrite, xstrdup(value));
 381                } else if (!strcmp(subkey, ".pushinsteadof")) {
 382                        rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 383                        if (!value)
 384                                return config_error_nonbool(key);
 385                        add_instead_of(rewrite, xstrdup(value));
 386                }
 387        }
 388        if (prefixcmp(key,  "remote."))
 389                return 0;
 390        name = key + 7;
 391        if (*name == '/') {
 392                warning("Config remote shorthand cannot begin with '/': %s",
 393                        name);
 394                return 0;
 395        }
 396        subkey = strrchr(name, '.');
 397        if (!subkey)
 398                return 0;
 399        remote = make_remote(name, subkey - name);
 400        remote->origin = REMOTE_CONFIG;
 401        if (!strcmp(subkey, ".mirror"))
 402                remote->mirror = git_config_bool(key, value);
 403        else if (!strcmp(subkey, ".skipdefaultupdate"))
 404                remote->skip_default_update = git_config_bool(key, value);
 405        else if (!strcmp(subkey, ".skipfetchall"))
 406                remote->skip_default_update = 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
 457static 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
 476static 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 = xstrdup("origin");
 484        current_branch = NULL;
 485        head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 486        if (head_ref && (flag & REF_ISSYMREF) &&
 487            !prefixcmp(head_ref, "refs/heads/")) {
 488                current_branch =
 489                        make_branch(head_ref + strlen("refs/heads/"), 0);
 490        }
 491        git_config(handle_config, NULL);
 492        alias_all_urls();
 493}
 494
 495/*
 496 * We need to make sure the tracking branches are well formed, but a
 497 * wildcard refspec in "struct refspec" must have a trailing slash. We
 498 * temporarily drop the trailing '/' while calling check_ref_format(),
 499 * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 500 * error return is Ok for a wildcard refspec.
 501 */
 502static int verify_refname(char *name, int is_glob)
 503{
 504        int result;
 505
 506        result = check_ref_format(name);
 507        if (is_glob && result == CHECK_REF_FORMAT_WILDCARD)
 508                result = CHECK_REF_FORMAT_OK;
 509        return result;
 510}
 511
 512/*
 513 * This function frees a refspec array.
 514 * Warning: code paths should be checked to ensure that the src
 515 *          and dst pointers are always freeable pointers as well
 516 *          as the refspec pointer itself.
 517 */
 518static void free_refspecs(struct refspec *refspec, int nr_refspec)
 519{
 520        int i;
 521
 522        if (!refspec)
 523                return;
 524
 525        for (i = 0; i < nr_refspec; i++) {
 526                free(refspec[i].src);
 527                free(refspec[i].dst);
 528        }
 529        free(refspec);
 530}
 531
 532static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 533{
 534        int i;
 535        int st;
 536        struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 537
 538        for (i = 0; i < nr_refspec; i++) {
 539                size_t llen;
 540                int is_glob;
 541                const char *lhs, *rhs;
 542
 543                is_glob = 0;
 544
 545                lhs = refspec[i];
 546                if (*lhs == '+') {
 547                        rs[i].force = 1;
 548                        lhs++;
 549                }
 550
 551                rhs = strrchr(lhs, ':');
 552
 553                /*
 554                 * Before going on, special case ":" (or "+:") as a refspec
 555                 * for matching refs.
 556                 */
 557                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 558                        rs[i].matching = 1;
 559                        continue;
 560                }
 561
 562                if (rhs) {
 563                        size_t rlen = strlen(++rhs);
 564                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 565                        rs[i].dst = xstrndup(rhs, rlen);
 566                }
 567
 568                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 569                if (1 <= llen && memchr(lhs, '*', llen)) {
 570                        if ((rhs && !is_glob) || (!rhs && fetch))
 571                                goto invalid;
 572                        is_glob = 1;
 573                } else if (rhs && is_glob) {
 574                        goto invalid;
 575                }
 576
 577                rs[i].pattern = is_glob;
 578                rs[i].src = xstrndup(lhs, llen);
 579
 580                if (fetch) {
 581                        /*
 582                         * LHS
 583                         * - empty is allowed; it means HEAD.
 584                         * - otherwise it must be a valid looking ref.
 585                         */
 586                        if (!*rs[i].src)
 587                                ; /* empty is ok */
 588                        else {
 589                                st = verify_refname(rs[i].src, is_glob);
 590                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 591                                        goto invalid;
 592                        }
 593                        /*
 594                         * RHS
 595                         * - missing is ok, and is same as empty.
 596                         * - empty is ok; it means not to store.
 597                         * - otherwise it must be a valid looking ref.
 598                         */
 599                        if (!rs[i].dst) {
 600                                ; /* ok */
 601                        } else if (!*rs[i].dst) {
 602                                ; /* ok */
 603                        } else {
 604                                st = verify_refname(rs[i].dst, is_glob);
 605                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 606                                        goto invalid;
 607                        }
 608                } else {
 609                        /*
 610                         * LHS
 611                         * - empty is allowed; it means delete.
 612                         * - when wildcarded, it must be a valid looking ref.
 613                         * - otherwise, it must be an extended SHA-1, but
 614                         *   there is no existing way to validate this.
 615                         */
 616                        if (!*rs[i].src)
 617                                ; /* empty is ok */
 618                        else if (is_glob) {
 619                                st = verify_refname(rs[i].src, is_glob);
 620                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 621                                        goto invalid;
 622                        }
 623                        else
 624                                ; /* anything goes, for now */
 625                        /*
 626                         * RHS
 627                         * - missing is allowed, but LHS then must be a
 628                         *   valid looking ref.
 629                         * - empty is not allowed.
 630                         * - otherwise it must be a valid looking ref.
 631                         */
 632                        if (!rs[i].dst) {
 633                                st = verify_refname(rs[i].src, is_glob);
 634                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 635                                        goto invalid;
 636                        } else if (!*rs[i].dst) {
 637                                goto invalid;
 638                        } else {
 639                                st = verify_refname(rs[i].dst, is_glob);
 640                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 641                                        goto invalid;
 642                        }
 643                }
 644        }
 645        return rs;
 646
 647 invalid:
 648        if (verify) {
 649                /*
 650                 * nr_refspec must be greater than zero and i must be valid
 651                 * since it is only possible to reach this point from within
 652                 * the for loop above.
 653                 */
 654                free_refspecs(rs, i+1);
 655                return NULL;
 656        }
 657        die("Invalid refspec '%s'", refspec[i]);
 658}
 659
 660int valid_fetch_refspec(const char *fetch_refspec_str)
 661{
 662        struct refspec *refspec;
 663
 664        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 665        free_refspecs(refspec, 1);
 666        return !!refspec;
 667}
 668
 669struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 670{
 671        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 672}
 673
 674static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 675{
 676        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 677}
 678
 679void free_refspec(int nr_refspec, struct refspec *refspec)
 680{
 681        int i;
 682        for (i = 0; i < nr_refspec; i++) {
 683                free(refspec[i].src);
 684                free(refspec[i].dst);
 685        }
 686        free(refspec);
 687}
 688
 689static int valid_remote_nick(const char *name)
 690{
 691        if (!name[0] || is_dot_or_dotdot(name))
 692                return 0;
 693        return !strchr(name, '/'); /* no slash */
 694}
 695
 696struct remote *remote_get(const char *name)
 697{
 698        struct remote *ret;
 699        int name_given = 0;
 700
 701        read_config();
 702        if (name)
 703                name_given = 1;
 704        else {
 705                name = default_remote_name;
 706                name_given = explicit_default_remote_name;
 707        }
 708
 709        ret = make_remote(name, 0);
 710        if (valid_remote_nick(name)) {
 711                if (!valid_remote(ret))
 712                        read_remotes_file(ret);
 713                if (!valid_remote(ret))
 714                        read_branches_file(ret);
 715        }
 716        if (name_given && !valid_remote(ret))
 717                add_url_alias(ret, name);
 718        if (!valid_remote(ret))
 719                return NULL;
 720        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 721        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 722        return ret;
 723}
 724
 725int remote_is_configured(const char *name)
 726{
 727        int i;
 728        read_config();
 729
 730        for (i = 0; i < remotes_nr; i++)
 731                if (!strcmp(name, remotes[i]->name))
 732                        return 1;
 733        return 0;
 734}
 735
 736int for_each_remote(each_remote_fn fn, void *priv)
 737{
 738        int i, result = 0;
 739        read_config();
 740        for (i = 0; i < remotes_nr && !result; i++) {
 741                struct remote *r = remotes[i];
 742                if (!r)
 743                        continue;
 744                if (!r->fetch)
 745                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 746                                                       r->fetch_refspec);
 747                if (!r->push)
 748                        r->push = parse_push_refspec(r->push_refspec_nr,
 749                                                     r->push_refspec);
 750                result = fn(r, priv);
 751        }
 752        return result;
 753}
 754
 755void ref_remove_duplicates(struct ref *ref_map)
 756{
 757        struct string_list refs = { NULL, 0, 0, 0 };
 758        struct string_list_item *item = NULL;
 759        struct ref *prev = NULL, *next = NULL;
 760        for (; ref_map; prev = ref_map, ref_map = next) {
 761                next = ref_map->next;
 762                if (!ref_map->peer_ref)
 763                        continue;
 764
 765                item = string_list_lookup(&refs, ref_map->peer_ref->name);
 766                if (item) {
 767                        if (strcmp(((struct ref *)item->util)->name,
 768                                   ref_map->name))
 769                                die("%s tracks both %s and %s",
 770                                    ref_map->peer_ref->name,
 771                                    ((struct ref *)item->util)->name,
 772                                    ref_map->name);
 773                        prev->next = ref_map->next;
 774                        free(ref_map->peer_ref);
 775                        free(ref_map);
 776                        ref_map = prev; /* skip this; we freed it */
 777                        continue;
 778                }
 779
 780                item = string_list_insert(&refs, ref_map->peer_ref->name);
 781                item->util = ref_map;
 782        }
 783        string_list_clear(&refs, 0);
 784}
 785
 786int remote_has_url(struct remote *remote, const char *url)
 787{
 788        int i;
 789        for (i = 0; i < remote->url_nr; i++) {
 790                if (!strcmp(remote->url[i], url))
 791                        return 1;
 792        }
 793        return 0;
 794}
 795
 796static int match_name_with_pattern(const char *key, const char *name,
 797                                   const char *value, char **result)
 798{
 799        const char *kstar = strchr(key, '*');
 800        size_t klen;
 801        size_t ksuffixlen;
 802        size_t namelen;
 803        int ret;
 804        if (!kstar)
 805                die("Key '%s' of pattern had no '*'", key);
 806        klen = kstar - key;
 807        ksuffixlen = strlen(kstar + 1);
 808        namelen = strlen(name);
 809        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 810                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 811        if (ret && value) {
 812                const char *vstar = strchr(value, '*');
 813                size_t vlen;
 814                size_t vsuffixlen;
 815                if (!vstar)
 816                        die("Value '%s' of pattern has no '*'", value);
 817                vlen = vstar - value;
 818                vsuffixlen = strlen(vstar + 1);
 819                *result = xmalloc(vlen + vsuffixlen +
 820                                  strlen(name) -
 821                                  klen - ksuffixlen + 1);
 822                strncpy(*result, value, vlen);
 823                strncpy(*result + vlen,
 824                        name + klen, namelen - klen - ksuffixlen);
 825                strcpy(*result + vlen + namelen - klen - ksuffixlen,
 826                       vstar + 1);
 827        }
 828        return ret;
 829}
 830
 831char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 832                     const char *name)
 833{
 834        int i;
 835        char *ret = NULL;
 836        for (i = 0; i < nr_refspec; i++) {
 837                struct refspec *refspec = refspecs + i;
 838                if (refspec->pattern) {
 839                        if (match_name_with_pattern(refspec->src, name,
 840                                                    refspec->dst, &ret))
 841                                return ret;
 842                } else if (!strcmp(refspec->src, name))
 843                        return strdup(refspec->dst);
 844        }
 845        return NULL;
 846}
 847
 848int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 849{
 850        int find_src = refspec->src == NULL;
 851        char *needle, **result;
 852        int i;
 853
 854        if (find_src) {
 855                if (!refspec->dst)
 856                        return error("find_tracking: need either src or dst");
 857                needle = refspec->dst;
 858                result = &refspec->src;
 859        } else {
 860                needle = refspec->src;
 861                result = &refspec->dst;
 862        }
 863
 864        for (i = 0; i < remote->fetch_refspec_nr; i++) {
 865                struct refspec *fetch = &remote->fetch[i];
 866                const char *key = find_src ? fetch->dst : fetch->src;
 867                const char *value = find_src ? fetch->src : fetch->dst;
 868                if (!fetch->dst)
 869                        continue;
 870                if (fetch->pattern) {
 871                        if (match_name_with_pattern(key, needle, value, result)) {
 872                                refspec->force = fetch->force;
 873                                return 0;
 874                        }
 875                } else if (!strcmp(needle, key)) {
 876                        *result = xstrdup(value);
 877                        refspec->force = fetch->force;
 878                        return 0;
 879                }
 880        }
 881        return -1;
 882}
 883
 884static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 885                const char *name)
 886{
 887        size_t len = strlen(name);
 888        struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 889        memcpy(ref->name, prefix, prefixlen);
 890        memcpy(ref->name + prefixlen, name, len);
 891        return ref;
 892}
 893
 894struct ref *alloc_ref(const char *name)
 895{
 896        return alloc_ref_with_prefix("", 0, name);
 897}
 898
 899static struct ref *copy_ref(const struct ref *ref)
 900{
 901        struct ref *cpy;
 902        size_t len;
 903        if (!ref)
 904                return NULL;
 905        len = strlen(ref->name);
 906        cpy = xmalloc(sizeof(struct ref) + len + 1);
 907        memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 908        cpy->next = NULL;
 909        cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 910        cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 911        cpy->peer_ref = copy_ref(ref->peer_ref);
 912        return cpy;
 913}
 914
 915struct ref *copy_ref_list(const struct ref *ref)
 916{
 917        struct ref *ret = NULL;
 918        struct ref **tail = &ret;
 919        while (ref) {
 920                *tail = copy_ref(ref);
 921                ref = ref->next;
 922                tail = &((*tail)->next);
 923        }
 924        return ret;
 925}
 926
 927static void free_ref(struct ref *ref)
 928{
 929        if (!ref)
 930                return;
 931        free_ref(ref->peer_ref);
 932        free(ref->remote_status);
 933        free(ref->symref);
 934        free(ref);
 935}
 936
 937void free_refs(struct ref *ref)
 938{
 939        struct ref *next;
 940        while (ref) {
 941                next = ref->next;
 942                free_ref(ref);
 943                ref = next;
 944        }
 945}
 946
 947static int count_refspec_match(const char *pattern,
 948                               struct ref *refs,
 949                               struct ref **matched_ref)
 950{
 951        int patlen = strlen(pattern);
 952        struct ref *matched_weak = NULL;
 953        struct ref *matched = NULL;
 954        int weak_match = 0;
 955        int match = 0;
 956
 957        for (weak_match = match = 0; refs; refs = refs->next) {
 958                char *name = refs->name;
 959                int namelen = strlen(name);
 960
 961                if (!refname_match(pattern, name, ref_rev_parse_rules))
 962                        continue;
 963
 964                /* A match is "weak" if it is with refs outside
 965                 * heads or tags, and did not specify the pattern
 966                 * in full (e.g. "refs/remotes/origin/master") or at
 967                 * least from the toplevel (e.g. "remotes/origin/master");
 968                 * otherwise "git push $URL master" would result in
 969                 * ambiguity between remotes/origin/master and heads/master
 970                 * at the remote site.
 971                 */
 972                if (namelen != patlen &&
 973                    patlen != namelen - 5 &&
 974                    prefixcmp(name, "refs/heads/") &&
 975                    prefixcmp(name, "refs/tags/")) {
 976                        /* We want to catch the case where only weak
 977                         * matches are found and there are multiple
 978                         * matches, and where more than one strong
 979                         * matches are found, as ambiguous.  One
 980                         * strong match with zero or more weak matches
 981                         * are acceptable as a unique match.
 982                         */
 983                        matched_weak = refs;
 984                        weak_match++;
 985                }
 986                else {
 987                        matched = refs;
 988                        match++;
 989                }
 990        }
 991        if (!matched) {
 992                *matched_ref = matched_weak;
 993                return weak_match;
 994        }
 995        else {
 996                *matched_ref = matched;
 997                return match;
 998        }
 999}
1000
1001static void tail_link_ref(struct ref *ref, struct ref ***tail)
1002{
1003        **tail = ref;
1004        while (ref->next)
1005                ref = ref->next;
1006        *tail = &ref->next;
1007}
1008
1009static struct ref *try_explicit_object_name(const char *name)
1010{
1011        unsigned char sha1[20];
1012        struct ref *ref;
1013
1014        if (!*name) {
1015                ref = alloc_ref("(delete)");
1016                hashclr(ref->new_sha1);
1017                return ref;
1018        }
1019        if (get_sha1(name, sha1))
1020                return NULL;
1021        ref = alloc_ref(name);
1022        hashcpy(ref->new_sha1, sha1);
1023        return ref;
1024}
1025
1026static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1027{
1028        struct ref *ret = alloc_ref(name);
1029        tail_link_ref(ret, tail);
1030        return ret;
1031}
1032
1033static char *guess_ref(const char *name, struct ref *peer)
1034{
1035        struct strbuf buf = STRBUF_INIT;
1036        unsigned char sha1[20];
1037
1038        const char *r = resolve_ref(peer->name, sha1, 1, NULL);
1039        if (!r)
1040                return NULL;
1041
1042        if (!prefixcmp(r, "refs/heads/"))
1043                strbuf_addstr(&buf, "refs/heads/");
1044        else if (!prefixcmp(r, "refs/tags/"))
1045                strbuf_addstr(&buf, "refs/tags/");
1046        else
1047                return NULL;
1048
1049        strbuf_addstr(&buf, name);
1050        return strbuf_detach(&buf, NULL);
1051}
1052
1053static int match_explicit(struct ref *src, struct ref *dst,
1054                          struct ref ***dst_tail,
1055                          struct refspec *rs)
1056{
1057        struct ref *matched_src, *matched_dst;
1058        int copy_src;
1059
1060        const char *dst_value = rs->dst;
1061        char *dst_guess;
1062
1063        if (rs->pattern || rs->matching)
1064                return 0;
1065
1066        matched_src = matched_dst = NULL;
1067        switch (count_refspec_match(rs->src, src, &matched_src)) {
1068        case 1:
1069                copy_src = 1;
1070                break;
1071        case 0:
1072                /* The source could be in the get_sha1() format
1073                 * not a reference name.  :refs/other is a
1074                 * way to delete 'other' ref at the remote end.
1075                 */
1076                matched_src = try_explicit_object_name(rs->src);
1077                if (!matched_src)
1078                        return error("src refspec %s does not match any.", rs->src);
1079                copy_src = 0;
1080                break;
1081        default:
1082                return error("src refspec %s matches more than one.", rs->src);
1083        }
1084
1085        if (!dst_value) {
1086                unsigned char sha1[20];
1087                int flag;
1088
1089                dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
1090                if (!dst_value ||
1091                    ((flag & REF_ISSYMREF) &&
1092                     prefixcmp(dst_value, "refs/heads/")))
1093                        die("%s cannot be resolved to branch.",
1094                            matched_src->name);
1095        }
1096
1097        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1098        case 1:
1099                break;
1100        case 0:
1101                if (!memcmp(dst_value, "refs/", 5))
1102                        matched_dst = make_linked_ref(dst_value, dst_tail);
1103                else if ((dst_guess = guess_ref(dst_value, matched_src)))
1104                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1105                else
1106                        error("unable to push to unqualified destination: %s\n"
1107                              "The destination refspec neither matches an "
1108                              "existing ref on the remote nor\n"
1109                              "begins with refs/, and we are unable to "
1110                              "guess a prefix based on the source ref.",
1111                              dst_value);
1112                break;
1113        default:
1114                matched_dst = NULL;
1115                error("dst refspec %s matches more than one.",
1116                      dst_value);
1117                break;
1118        }
1119        if (!matched_dst)
1120                return -1;
1121        if (matched_dst->peer_ref)
1122                return error("dst ref %s receives from more than one src.",
1123                      matched_dst->name);
1124        else {
1125                matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1126                matched_dst->force = rs->force;
1127        }
1128        return 0;
1129}
1130
1131static int match_explicit_refs(struct ref *src, struct ref *dst,
1132                               struct ref ***dst_tail, struct refspec *rs,
1133                               int rs_nr)
1134{
1135        int i, errs;
1136        for (i = errs = 0; i < rs_nr; i++)
1137                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1138        return errs;
1139}
1140
1141static const struct refspec *check_pattern_match(const struct refspec *rs,
1142                                                 int rs_nr,
1143                                                 const struct ref *src)
1144{
1145        int i;
1146        int matching_refs = -1;
1147        for (i = 0; i < rs_nr; i++) {
1148                if (rs[i].matching &&
1149                    (matching_refs == -1 || rs[i].force)) {
1150                        matching_refs = i;
1151                        continue;
1152                }
1153
1154                if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1155                                                             NULL, NULL))
1156                        return rs + i;
1157        }
1158        if (matching_refs != -1)
1159                return rs + matching_refs;
1160        else
1161                return NULL;
1162}
1163
1164static struct ref **tail_ref(struct ref **head)
1165{
1166        struct ref **tail = head;
1167        while (*tail)
1168                tail = &((*tail)->next);
1169        return tail;
1170}
1171
1172/*
1173 * Note. This is used only by "push"; refspec matching rules for
1174 * push and fetch are subtly different, so do not try to reuse it
1175 * without thinking.
1176 */
1177int match_refs(struct ref *src, struct ref **dst,
1178               int nr_refspec, const char **refspec, int flags)
1179{
1180        struct refspec *rs;
1181        int send_all = flags & MATCH_REFS_ALL;
1182        int send_mirror = flags & MATCH_REFS_MIRROR;
1183        int errs;
1184        static const char *default_refspec[] = { ":", NULL };
1185        struct ref **dst_tail = tail_ref(dst);
1186
1187        if (!nr_refspec) {
1188                nr_refspec = 1;
1189                refspec = default_refspec;
1190        }
1191        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1192        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1193
1194        /* pick the remainder */
1195        for ( ; src; src = src->next) {
1196                struct ref *dst_peer;
1197                const struct refspec *pat = NULL;
1198                char *dst_name;
1199                if (src->peer_ref)
1200                        continue;
1201
1202                pat = check_pattern_match(rs, nr_refspec, src);
1203                if (!pat)
1204                        continue;
1205
1206                if (pat->matching) {
1207                        /*
1208                         * "matching refs"; traditionally we pushed everything
1209                         * including refs outside refs/heads/ hierarchy, but
1210                         * that does not make much sense these days.
1211                         */
1212                        if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1213                                continue;
1214                        dst_name = xstrdup(src->name);
1215
1216                } else {
1217                        const char *dst_side = pat->dst ? pat->dst : pat->src;
1218                        if (!match_name_with_pattern(pat->src, src->name,
1219                                                     dst_side, &dst_name))
1220                                die("Didn't think it matches any more");
1221                }
1222                dst_peer = find_ref_by_name(*dst, dst_name);
1223                if (dst_peer) {
1224                        if (dst_peer->peer_ref)
1225                                /* We're already sending something to this ref. */
1226                                goto free_name;
1227
1228                } else {
1229                        if (pat->matching && !(send_all || send_mirror))
1230                                /*
1231                                 * Remote doesn't have it, and we have no
1232                                 * explicit pattern, and we don't have
1233                                 * --all nor --mirror.
1234                                 */
1235                                goto free_name;
1236
1237                        /* Create a new one and link it */
1238                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1239                        hashcpy(dst_peer->new_sha1, src->new_sha1);
1240                }
1241                dst_peer->peer_ref = copy_ref(src);
1242                dst_peer->force = pat->force;
1243        free_name:
1244                free(dst_name);
1245        }
1246        if (errs)
1247                return -1;
1248        return 0;
1249}
1250
1251void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1252        int force_update)
1253{
1254        struct ref *ref;
1255
1256        for (ref = remote_refs; ref; ref = ref->next) {
1257                if (ref->peer_ref)
1258                        hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1259                else if (!send_mirror)
1260                        continue;
1261
1262                ref->deletion = is_null_sha1(ref->new_sha1);
1263                if (!ref->deletion &&
1264                        !hashcmp(ref->old_sha1, ref->new_sha1)) {
1265                        ref->status = REF_STATUS_UPTODATE;
1266                        continue;
1267                }
1268
1269                /* This part determines what can overwrite what.
1270                 * The rules are:
1271                 *
1272                 * (0) you can always use --force or +A:B notation to
1273                 *     selectively force individual ref pairs.
1274                 *
1275                 * (1) if the old thing does not exist, it is OK.
1276                 *
1277                 * (2) if you do not have the old thing, you are not allowed
1278                 *     to overwrite it; you would not know what you are losing
1279                 *     otherwise.
1280                 *
1281                 * (3) if both new and old are commit-ish, and new is a
1282                 *     descendant of old, it is OK.
1283                 *
1284                 * (4) regardless of all of the above, removing :B is
1285                 *     always allowed.
1286                 */
1287
1288                ref->nonfastforward =
1289                        !ref->deletion &&
1290                        !is_null_sha1(ref->old_sha1) &&
1291                        (!has_sha1_file(ref->old_sha1)
1292                          || !ref_newer(ref->new_sha1, ref->old_sha1));
1293
1294                if (ref->nonfastforward && !ref->force && !force_update) {
1295                        ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
1296                        continue;
1297                }
1298        }
1299}
1300
1301struct branch *branch_get(const char *name)
1302{
1303        struct branch *ret;
1304
1305        read_config();
1306        if (!name || !*name || !strcmp(name, "HEAD"))
1307                ret = current_branch;
1308        else
1309                ret = make_branch(name, 0);
1310        if (ret && ret->remote_name) {
1311                ret->remote = remote_get(ret->remote_name);
1312                if (ret->merge_nr) {
1313                        int i;
1314                        ret->merge = xcalloc(sizeof(*ret->merge),
1315                                             ret->merge_nr);
1316                        for (i = 0; i < ret->merge_nr; i++) {
1317                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1318                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1319                                if (remote_find_tracking(ret->remote, ret->merge[i])
1320                                    && !strcmp(ret->remote_name, "."))
1321                                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1322                        }
1323                }
1324        }
1325        return ret;
1326}
1327
1328int branch_has_merge_config(struct branch *branch)
1329{
1330        return branch && !!branch->merge;
1331}
1332
1333int branch_merge_matches(struct branch *branch,
1334                                 int i,
1335                                 const char *refname)
1336{
1337        if (!branch || i < 0 || i >= branch->merge_nr)
1338                return 0;
1339        return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1340}
1341
1342static struct ref *get_expanded_map(const struct ref *remote_refs,
1343                                    const struct refspec *refspec)
1344{
1345        const struct ref *ref;
1346        struct ref *ret = NULL;
1347        struct ref **tail = &ret;
1348
1349        char *expn_name;
1350
1351        for (ref = remote_refs; ref; ref = ref->next) {
1352                if (strchr(ref->name, '^'))
1353                        continue; /* a dereference item */
1354                if (match_name_with_pattern(refspec->src, ref->name,
1355                                            refspec->dst, &expn_name)) {
1356                        struct ref *cpy = copy_ref(ref);
1357
1358                        cpy->peer_ref = alloc_ref(expn_name);
1359                        free(expn_name);
1360                        if (refspec->force)
1361                                cpy->peer_ref->force = 1;
1362                        *tail = cpy;
1363                        tail = &cpy->next;
1364                }
1365        }
1366
1367        return ret;
1368}
1369
1370static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1371{
1372        const struct ref *ref;
1373        for (ref = refs; ref; ref = ref->next) {
1374                if (refname_match(name, ref->name, ref_fetch_rules))
1375                        return ref;
1376        }
1377        return NULL;
1378}
1379
1380struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1381{
1382        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1383
1384        if (!ref)
1385                return NULL;
1386
1387        return copy_ref(ref);
1388}
1389
1390static struct ref *get_local_ref(const char *name)
1391{
1392        if (!name || name[0] == '\0')
1393                return NULL;
1394
1395        if (!prefixcmp(name, "refs/"))
1396                return alloc_ref(name);
1397
1398        if (!prefixcmp(name, "heads/") ||
1399            !prefixcmp(name, "tags/") ||
1400            !prefixcmp(name, "remotes/"))
1401                return alloc_ref_with_prefix("refs/", 5, name);
1402
1403        return alloc_ref_with_prefix("refs/heads/", 11, name);
1404}
1405
1406int get_fetch_map(const struct ref *remote_refs,
1407                  const struct refspec *refspec,
1408                  struct ref ***tail,
1409                  int missing_ok)
1410{
1411        struct ref *ref_map, **rmp;
1412
1413        if (refspec->pattern) {
1414                ref_map = get_expanded_map(remote_refs, refspec);
1415        } else {
1416                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1417
1418                ref_map = get_remote_ref(remote_refs, name);
1419                if (!missing_ok && !ref_map)
1420                        die("Couldn't find remote ref %s", name);
1421                if (ref_map) {
1422                        ref_map->peer_ref = get_local_ref(refspec->dst);
1423                        if (ref_map->peer_ref && refspec->force)
1424                                ref_map->peer_ref->force = 1;
1425                }
1426        }
1427
1428        for (rmp = &ref_map; *rmp; ) {
1429                if ((*rmp)->peer_ref) {
1430                        int st = check_ref_format((*rmp)->peer_ref->name + 5);
1431                        if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1432                                struct ref *ignore = *rmp;
1433                                error("* Ignoring funny ref '%s' locally",
1434                                      (*rmp)->peer_ref->name);
1435                                *rmp = (*rmp)->next;
1436                                free(ignore->peer_ref);
1437                                free(ignore);
1438                                continue;
1439                        }
1440                }
1441                rmp = &((*rmp)->next);
1442        }
1443
1444        if (ref_map)
1445                tail_link_ref(ref_map, tail);
1446
1447        return 0;
1448}
1449
1450int resolve_remote_symref(struct ref *ref, struct ref *list)
1451{
1452        if (!ref->symref)
1453                return 0;
1454        for (; list; list = list->next)
1455                if (!strcmp(ref->symref, list->name)) {
1456                        hashcpy(ref->old_sha1, list->old_sha1);
1457                        return 0;
1458                }
1459        return 1;
1460}
1461
1462static void unmark_and_free(struct commit_list *list, unsigned int mark)
1463{
1464        while (list) {
1465                struct commit_list *temp = list;
1466                temp->item->object.flags &= ~mark;
1467                list = temp->next;
1468                free(temp);
1469        }
1470}
1471
1472int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1473{
1474        struct object *o;
1475        struct commit *old, *new;
1476        struct commit_list *list, *used;
1477        int found = 0;
1478
1479        /* Both new and old must be commit-ish and new is descendant of
1480         * old.  Otherwise we require --force.
1481         */
1482        o = deref_tag(parse_object(old_sha1), NULL, 0);
1483        if (!o || o->type != OBJ_COMMIT)
1484                return 0;
1485        old = (struct commit *) o;
1486
1487        o = deref_tag(parse_object(new_sha1), NULL, 0);
1488        if (!o || o->type != OBJ_COMMIT)
1489                return 0;
1490        new = (struct commit *) o;
1491
1492        if (parse_commit(new) < 0)
1493                return 0;
1494
1495        used = list = NULL;
1496        commit_list_insert(new, &list);
1497        while (list) {
1498                new = pop_most_recent_commit(&list, TMP_MARK);
1499                commit_list_insert(new, &used);
1500                if (new == old) {
1501                        found = 1;
1502                        break;
1503                }
1504        }
1505        unmark_and_free(list, TMP_MARK);
1506        unmark_and_free(used, TMP_MARK);
1507        return found;
1508}
1509
1510/*
1511 * Return true if there is anything to report, otherwise false.
1512 */
1513int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1514{
1515        unsigned char sha1[20];
1516        struct commit *ours, *theirs;
1517        char symmetric[84];
1518        struct rev_info revs;
1519        const char *rev_argv[10], *base;
1520        int rev_argc;
1521
1522        /*
1523         * Nothing to report unless we are marked to build on top of
1524         * somebody else.
1525         */
1526        if (!branch ||
1527            !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1528                return 0;
1529
1530        /*
1531         * If what we used to build on no longer exists, there is
1532         * nothing to report.
1533         */
1534        base = branch->merge[0]->dst;
1535        if (!resolve_ref(base, sha1, 1, NULL))
1536                return 0;
1537        theirs = lookup_commit_reference(sha1);
1538        if (!theirs)
1539                return 0;
1540
1541        if (!resolve_ref(branch->refname, sha1, 1, NULL))
1542                return 0;
1543        ours = lookup_commit_reference(sha1);
1544        if (!ours)
1545                return 0;
1546
1547        /* are we the same? */
1548        if (theirs == ours)
1549                return 0;
1550
1551        /* Run "rev-list --left-right ours...theirs" internally... */
1552        rev_argc = 0;
1553        rev_argv[rev_argc++] = NULL;
1554        rev_argv[rev_argc++] = "--left-right";
1555        rev_argv[rev_argc++] = symmetric;
1556        rev_argv[rev_argc++] = "--";
1557        rev_argv[rev_argc] = NULL;
1558
1559        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1560        strcpy(symmetric + 40, "...");
1561        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1562
1563        init_revisions(&revs, NULL);
1564        setup_revisions(rev_argc, rev_argv, &revs, NULL);
1565        prepare_revision_walk(&revs);
1566
1567        /* ... and count the commits on each side. */
1568        *num_ours = 0;
1569        *num_theirs = 0;
1570        while (1) {
1571                struct commit *c = get_revision(&revs);
1572                if (!c)
1573                        break;
1574                if (c->object.flags & SYMMETRIC_LEFT)
1575                        (*num_ours)++;
1576                else
1577                        (*num_theirs)++;
1578        }
1579
1580        /* clear object flags smudged by the above traversal */
1581        clear_commit_marks(ours, ALL_REV_FLAGS);
1582        clear_commit_marks(theirs, ALL_REV_FLAGS);
1583        return 1;
1584}
1585
1586/*
1587 * Return true when there is anything to report, otherwise false.
1588 */
1589int format_tracking_info(struct branch *branch, struct strbuf *sb)
1590{
1591        int num_ours, num_theirs;
1592        const char *base;
1593
1594        if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1595                return 0;
1596
1597        base = branch->merge[0]->dst;
1598        base = shorten_unambiguous_ref(base, 0);
1599        if (!num_theirs)
1600                strbuf_addf(sb, "Your branch is ahead of '%s' "
1601                            "by %d commit%s.\n",
1602                            base, num_ours, (num_ours == 1) ? "" : "s");
1603        else if (!num_ours)
1604                strbuf_addf(sb, "Your branch is behind '%s' "
1605                            "by %d commit%s, "
1606                            "and can be fast-forwarded.\n",
1607                            base, num_theirs, (num_theirs == 1) ? "" : "s");
1608        else
1609                strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1610                            "and have %d and %d different commit(s) each, "
1611                            "respectively.\n",
1612                            base, num_ours, num_theirs);
1613        return 1;
1614}
1615
1616static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1617{
1618        struct ref ***local_tail = cb_data;
1619        struct ref *ref;
1620        int len;
1621
1622        /* we already know it starts with refs/ to get here */
1623        if (check_ref_format(refname + 5))
1624                return 0;
1625
1626        len = strlen(refname) + 1;
1627        ref = xcalloc(1, sizeof(*ref) + len);
1628        hashcpy(ref->new_sha1, sha1);
1629        memcpy(ref->name, refname, len);
1630        **local_tail = ref;
1631        *local_tail = &ref->next;
1632        return 0;
1633}
1634
1635struct ref *get_local_heads(void)
1636{
1637        struct ref *local_refs = NULL, **local_tail = &local_refs;
1638        for_each_ref(one_local_ref, &local_tail);
1639        return local_refs;
1640}
1641
1642struct ref *guess_remote_head(const struct ref *head,
1643                              const struct ref *refs,
1644                              int all)
1645{
1646        const struct ref *r;
1647        struct ref *list = NULL;
1648        struct ref **tail = &list;
1649
1650        if (!head)
1651                return NULL;
1652
1653        /*
1654         * Some transports support directly peeking at
1655         * where HEAD points; if that is the case, then
1656         * we don't have to guess.
1657         */
1658        if (head->symref)
1659                return copy_ref(find_ref_by_name(refs, head->symref));
1660
1661        /* If refs/heads/master could be right, it is. */
1662        if (!all) {
1663                r = find_ref_by_name(refs, "refs/heads/master");
1664                if (r && !hashcmp(r->old_sha1, head->old_sha1))
1665                        return copy_ref(r);
1666        }
1667
1668        /* Look for another ref that points there */
1669        for (r = refs; r; r = r->next) {
1670                if (r != head && !hashcmp(r->old_sha1, head->old_sha1)) {
1671                        *tail = copy_ref(r);
1672                        tail = &((*tail)->next);
1673                        if (!all)
1674                                break;
1675                }
1676        }
1677
1678        return list;
1679}
1680
1681struct stale_heads_info {
1682        struct remote *remote;
1683        struct string_list *ref_names;
1684        struct ref **stale_refs_tail;
1685};
1686
1687static int get_stale_heads_cb(const char *refname,
1688        const unsigned char *sha1, int flags, void *cb_data)
1689{
1690        struct stale_heads_info *info = cb_data;
1691        struct refspec refspec;
1692        memset(&refspec, 0, sizeof(refspec));
1693        refspec.dst = (char *)refname;
1694        if (!remote_find_tracking(info->remote, &refspec)) {
1695                if (!((flags & REF_ISSYMREF) ||
1696                    string_list_has_string(info->ref_names, refspec.src))) {
1697                        struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1698                        hashcpy(ref->new_sha1, sha1);
1699                }
1700        }
1701        return 0;
1702}
1703
1704struct ref *get_stale_heads(struct remote *remote, struct ref *fetch_map)
1705{
1706        struct ref *ref, *stale_refs = NULL;
1707        struct string_list ref_names = { NULL, 0, 0, 0 };
1708        struct stale_heads_info info;
1709        info.remote = remote;
1710        info.ref_names = &ref_names;
1711        info.stale_refs_tail = &stale_refs;
1712        for (ref = fetch_map; ref; ref = ref->next)
1713                string_list_append(&ref_names, ref->name);
1714        sort_string_list(&ref_names);
1715        for_each_ref(get_stale_heads_cb, &info);
1716        string_list_clear(&ref_names, 0);
1717        return stale_refs;
1718}