4085c517e4de40474738794ce3c5d0dc1901134d
   1#include "cache.h"
   2#include "remote.h"
   3#include "refs.h"
   4
   5static struct remote **remotes;
   6static int allocated_remotes;
   7
   8static struct branch **branches;
   9static int allocated_branches;
  10
  11static struct branch *current_branch;
  12static const char *default_remote_name;
  13
  14#define BUF_SIZE (2048)
  15static char buffer[BUF_SIZE];
  16
  17static void add_push_refspec(struct remote *remote, const char *ref)
  18{
  19        int nr = remote->push_refspec_nr + 1;
  20        remote->push_refspec =
  21                xrealloc(remote->push_refspec, nr * sizeof(char *));
  22        remote->push_refspec[nr-1] = ref;
  23        remote->push_refspec_nr = nr;
  24}
  25
  26static void add_fetch_refspec(struct remote *remote, const char *ref)
  27{
  28        int nr = remote->fetch_refspec_nr + 1;
  29        remote->fetch_refspec =
  30                xrealloc(remote->fetch_refspec, nr * sizeof(char *));
  31        remote->fetch_refspec[nr-1] = ref;
  32        remote->fetch_refspec_nr = nr;
  33}
  34
  35static void add_url(struct remote *remote, const char *url)
  36{
  37        int nr = remote->url_nr + 1;
  38        remote->url =
  39                xrealloc(remote->url, nr * sizeof(char *));
  40        remote->url[nr-1] = url;
  41        remote->url_nr = nr;
  42}
  43
  44static struct remote *make_remote(const char *name, int len)
  45{
  46        int i, empty = -1;
  47
  48        for (i = 0; i < allocated_remotes; i++) {
  49                if (!remotes[i]) {
  50                        if (empty < 0)
  51                                empty = i;
  52                } else {
  53                        if (len ? (!strncmp(name, remotes[i]->name, len) &&
  54                                   !remotes[i]->name[len]) :
  55                            !strcmp(name, remotes[i]->name))
  56                                return remotes[i];
  57                }
  58        }
  59
  60        if (empty < 0) {
  61                empty = allocated_remotes;
  62                allocated_remotes += allocated_remotes ? allocated_remotes : 1;
  63                remotes = xrealloc(remotes,
  64                                   sizeof(*remotes) * allocated_remotes);
  65                memset(remotes + empty, 0,
  66                       (allocated_remotes - empty) * sizeof(*remotes));
  67        }
  68        remotes[empty] = xcalloc(1, sizeof(struct remote));
  69        if (len)
  70                remotes[empty]->name = xstrndup(name, len);
  71        else
  72                remotes[empty]->name = xstrdup(name);
  73        return remotes[empty];
  74}
  75
  76static void add_merge(struct branch *branch, const char *name)
  77{
  78        int nr = branch->merge_nr + 1;
  79        branch->merge_name =
  80                xrealloc(branch->merge_name, nr * sizeof(char *));
  81        branch->merge_name[nr-1] = name;
  82        branch->merge_nr = nr;
  83}
  84
  85static struct branch *make_branch(const char *name, int len)
  86{
  87        int i, empty = -1;
  88        char *refname;
  89
  90        for (i = 0; i < allocated_branches; i++) {
  91                if (!branches[i]) {
  92                        if (empty < 0)
  93                                empty = i;
  94                } else {
  95                        if (len ? (!strncmp(name, branches[i]->name, len) &&
  96                                   !branches[i]->name[len]) :
  97                            !strcmp(name, branches[i]->name))
  98                                return branches[i];
  99                }
 100        }
 101
 102        if (empty < 0) {
 103                empty = allocated_branches;
 104                allocated_branches += allocated_branches ? allocated_branches : 1;
 105                branches = xrealloc(branches,
 106                                   sizeof(*branches) * allocated_branches);
 107                memset(branches + empty, 0,
 108                       (allocated_branches - empty) * sizeof(*branches));
 109        }
 110        branches[empty] = xcalloc(1, sizeof(struct branch));
 111        if (len)
 112                branches[empty]->name = xstrndup(name, len);
 113        else
 114                branches[empty]->name = xstrdup(name);
 115        refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
 116        strcpy(refname, "refs/heads/");
 117        strcpy(refname + strlen("refs/heads/"),
 118               branches[empty]->name);
 119        branches[empty]->refname = refname;
 120
 121        return branches[empty];
 122}
 123
 124static void read_remotes_file(struct remote *remote)
 125{
 126        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 127
 128        if (!f)
 129                return;
 130        while (fgets(buffer, BUF_SIZE, f)) {
 131                int value_list;
 132                char *s, *p;
 133
 134                if (!prefixcmp(buffer, "URL:")) {
 135                        value_list = 0;
 136                        s = buffer + 4;
 137                } else if (!prefixcmp(buffer, "Push:")) {
 138                        value_list = 1;
 139                        s = buffer + 5;
 140                } else if (!prefixcmp(buffer, "Pull:")) {
 141                        value_list = 2;
 142                        s = buffer + 5;
 143                } else
 144                        continue;
 145
 146                while (isspace(*s))
 147                        s++;
 148                if (!*s)
 149                        continue;
 150
 151                p = s + strlen(s);
 152                while (isspace(p[-1]))
 153                        *--p = 0;
 154
 155                switch (value_list) {
 156                case 0:
 157                        add_url(remote, xstrdup(s));
 158                        break;
 159                case 1:
 160                        add_push_refspec(remote, xstrdup(s));
 161                        break;
 162                case 2:
 163                        add_fetch_refspec(remote, xstrdup(s));
 164                        break;
 165                }
 166        }
 167        fclose(f);
 168}
 169
 170static void read_branches_file(struct remote *remote)
 171{
 172        const char *slash = strchr(remote->name, '/');
 173        char *frag;
 174        char *branch;
 175        int n = slash ? slash - remote->name : 1000;
 176        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 177        char *s, *p;
 178        int len;
 179
 180        if (!f)
 181                return;
 182        s = fgets(buffer, BUF_SIZE, f);
 183        fclose(f);
 184        if (!s)
 185                return;
 186        while (isspace(*s))
 187                s++;
 188        if (!*s)
 189                return;
 190        p = s + strlen(s);
 191        while (isspace(p[-1]))
 192                *--p = 0;
 193        len = p - s;
 194        if (slash)
 195                len += strlen(slash);
 196        p = xmalloc(len + 1);
 197        strcpy(p, s);
 198        if (slash)
 199                strcat(p, slash);
 200        frag = strchr(p, '#');
 201        if (frag) {
 202                *(frag++) = '\0';
 203                branch = xmalloc(strlen(frag) + 12);
 204                strcpy(branch, "refs/heads/");
 205                strcat(branch, frag);
 206        } else {
 207                branch = "refs/heads/master";
 208        }
 209        add_url(remote, p);
 210        add_fetch_refspec(remote, branch);
 211        remote->fetch_tags = 1; /* always auto-follow */
 212}
 213
 214static int handle_config(const char *key, const char *value)
 215{
 216        const char *name;
 217        const char *subkey;
 218        struct remote *remote;
 219        struct branch *branch;
 220        if (!prefixcmp(key, "branch.")) {
 221                name = key + 7;
 222                subkey = strrchr(name, '.');
 223                branch = make_branch(name, subkey - name);
 224                if (!subkey)
 225                        return 0;
 226                if (!value)
 227                        return 0;
 228                if (!strcmp(subkey, ".remote")) {
 229                        branch->remote_name = xstrdup(value);
 230                        if (branch == current_branch)
 231                                default_remote_name = branch->remote_name;
 232                } else if (!strcmp(subkey, ".merge"))
 233                        add_merge(branch, xstrdup(value));
 234                return 0;
 235        }
 236        if (prefixcmp(key,  "remote."))
 237                return 0;
 238        name = key + 7;
 239        subkey = strrchr(name, '.');
 240        if (!subkey)
 241                return error("Config with no key for remote %s", name);
 242        if (*subkey == '/') {
 243                warning("Config remote shorthand cannot begin with '/': %s", name);
 244                return 0;
 245        }
 246        remote = make_remote(name, subkey - name);
 247        if (!value) {
 248                /* if we ever have a boolean variable, e.g. "remote.*.disabled"
 249                 * [remote "frotz"]
 250                 *      disabled
 251                 * is a valid way to set it to true; we get NULL in value so
 252                 * we need to handle it here.
 253                 *
 254                 * if (!strcmp(subkey, ".disabled")) {
 255                 *      val = git_config_bool(key, value);
 256                 *      return 0;
 257                 * } else
 258                 *
 259                 */
 260                return 0; /* ignore unknown booleans */
 261        }
 262        if (!strcmp(subkey, ".url")) {
 263                add_url(remote, xstrdup(value));
 264        } else if (!strcmp(subkey, ".push")) {
 265                add_push_refspec(remote, xstrdup(value));
 266        } else if (!strcmp(subkey, ".fetch")) {
 267                add_fetch_refspec(remote, xstrdup(value));
 268        } else if (!strcmp(subkey, ".receivepack")) {
 269                if (!remote->receivepack)
 270                        remote->receivepack = xstrdup(value);
 271                else
 272                        error("more than one receivepack given, using the first");
 273        } else if (!strcmp(subkey, ".uploadpack")) {
 274                if (!remote->uploadpack)
 275                        remote->uploadpack = xstrdup(value);
 276                else
 277                        error("more than one uploadpack given, using the first");
 278        } else if (!strcmp(subkey, ".tagopt")) {
 279                if (!strcmp(value, "--no-tags"))
 280                        remote->fetch_tags = -1;
 281        }
 282        return 0;
 283}
 284
 285static void read_config(void)
 286{
 287        unsigned char sha1[20];
 288        const char *head_ref;
 289        int flag;
 290        if (default_remote_name) // did this already
 291                return;
 292        default_remote_name = xstrdup("origin");
 293        current_branch = NULL;
 294        head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 295        if (head_ref && (flag & REF_ISSYMREF) &&
 296            !prefixcmp(head_ref, "refs/heads/")) {
 297                current_branch =
 298                        make_branch(head_ref + strlen("refs/heads/"), 0);
 299        }
 300        git_config(handle_config);
 301}
 302
 303struct refspec *parse_ref_spec(int nr_refspec, const char **refspec)
 304{
 305        int i;
 306        struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 307        for (i = 0; i < nr_refspec; i++) {
 308                const char *sp, *ep, *gp;
 309                sp = refspec[i];
 310                if (*sp == '+') {
 311                        rs[i].force = 1;
 312                        sp++;
 313                }
 314                gp = strchr(sp, '*');
 315                ep = strchr(sp, ':');
 316                if (gp && ep && gp > ep)
 317                        gp = NULL;
 318                if (ep) {
 319                        if (ep[1]) {
 320                                const char *glob = strchr(ep + 1, '*');
 321                                if (!glob)
 322                                        gp = NULL;
 323                                if (gp)
 324                                        rs[i].dst = xstrndup(ep + 1,
 325                                                             glob - ep - 1);
 326                                else
 327                                        rs[i].dst = xstrdup(ep + 1);
 328                        }
 329                } else {
 330                        ep = sp + strlen(sp);
 331                }
 332                if (gp) {
 333                        rs[i].pattern = 1;
 334                        ep = gp;
 335                }
 336                rs[i].src = xstrndup(sp, ep - sp);
 337        }
 338        return rs;
 339}
 340
 341struct remote *remote_get(const char *name)
 342{
 343        struct remote *ret;
 344
 345        read_config();
 346        if (!name)
 347                name = default_remote_name;
 348        ret = make_remote(name, 0);
 349        if (name[0] != '/') {
 350                if (!ret->url)
 351                        read_remotes_file(ret);
 352                if (!ret->url)
 353                        read_branches_file(ret);
 354        }
 355        if (!ret->url)
 356                add_url(ret, name);
 357        if (!ret->url)
 358                return NULL;
 359        ret->fetch = parse_ref_spec(ret->fetch_refspec_nr, ret->fetch_refspec);
 360        ret->push = parse_ref_spec(ret->push_refspec_nr, ret->push_refspec);
 361        return ret;
 362}
 363
 364int for_each_remote(each_remote_fn fn, void *priv)
 365{
 366        int i, result = 0;
 367        read_config();
 368        for (i = 0; i < allocated_remotes && !result; i++) {
 369                struct remote *r = remotes[i];
 370                if (!r)
 371                        continue;
 372                if (!r->fetch)
 373                        r->fetch = parse_ref_spec(r->fetch_refspec_nr,
 374                                        r->fetch_refspec);
 375                if (!r->push)
 376                        r->push = parse_ref_spec(r->push_refspec_nr,
 377                                        r->push_refspec);
 378                result = fn(r, priv);
 379        }
 380        return result;
 381}
 382
 383void ref_remove_duplicates(struct ref *ref_map)
 384{
 385        struct ref **posn;
 386        struct ref *next;
 387        for (; ref_map; ref_map = ref_map->next) {
 388                if (!ref_map->peer_ref)
 389                        continue;
 390                posn = &ref_map->next;
 391                while (*posn) {
 392                        if ((*posn)->peer_ref &&
 393                            !strcmp((*posn)->peer_ref->name,
 394                                    ref_map->peer_ref->name)) {
 395                                if (strcmp((*posn)->name, ref_map->name))
 396                                        die("%s tracks both %s and %s",
 397                                            ref_map->peer_ref->name,
 398                                            (*posn)->name, ref_map->name);
 399                                next = (*posn)->next;
 400                                free((*posn)->peer_ref);
 401                                free(*posn);
 402                                *posn = next;
 403                        } else {
 404                                posn = &(*posn)->next;
 405                        }
 406                }
 407        }
 408}
 409
 410int remote_has_url(struct remote *remote, const char *url)
 411{
 412        int i;
 413        for (i = 0; i < remote->url_nr; i++) {
 414                if (!strcmp(remote->url[i], url))
 415                        return 1;
 416        }
 417        return 0;
 418}
 419
 420/*
 421 * Returns true if, under the matching rules for fetching, name is the
 422 * same as the given full name.
 423 */
 424static int ref_matches_abbrev(const char *name, const char *full)
 425{
 426        if (!prefixcmp(name, "refs/") || !strcmp(name, "HEAD"))
 427                return !strcmp(name, full);
 428        if (prefixcmp(full, "refs/"))
 429                return 0;
 430        if (!prefixcmp(name, "heads/") ||
 431            !prefixcmp(name, "tags/") ||
 432            !prefixcmp(name, "remotes/"))
 433                return !strcmp(name, full + 5);
 434        if (prefixcmp(full + 5, "heads/"))
 435                return 0;
 436        return !strcmp(full + 11, name);
 437}
 438
 439int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 440{
 441        int find_src = refspec->src == NULL;
 442        char *needle, **result;
 443        int i;
 444
 445        if (find_src) {
 446                if (!refspec->dst)
 447                        return error("find_tracking: need either src or dst");
 448                needle = refspec->dst;
 449                result = &refspec->src;
 450        } else {
 451                needle = refspec->src;
 452                result = &refspec->dst;
 453        }
 454
 455        for (i = 0; i < remote->fetch_refspec_nr; i++) {
 456                struct refspec *fetch = &remote->fetch[i];
 457                const char *key = find_src ? fetch->dst : fetch->src;
 458                const char *value = find_src ? fetch->src : fetch->dst;
 459                if (!fetch->dst)
 460                        continue;
 461                if (fetch->pattern) {
 462                        if (!prefixcmp(needle, key)) {
 463                                *result = xmalloc(strlen(value) +
 464                                                  strlen(needle) -
 465                                                  strlen(key) + 1);
 466                                strcpy(*result, value);
 467                                strcpy(*result + strlen(value),
 468                                       needle + strlen(key));
 469                                refspec->force = fetch->force;
 470                                return 0;
 471                        }
 472                } else if (!strcmp(needle, key)) {
 473                        *result = xstrdup(value);
 474                        refspec->force = fetch->force;
 475                        return 0;
 476                }
 477        }
 478        return -1;
 479}
 480
 481struct ref *alloc_ref(unsigned namelen)
 482{
 483        struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 484        memset(ret, 0, sizeof(struct ref) + namelen);
 485        return ret;
 486}
 487
 488static struct ref *copy_ref(struct ref *ref)
 489{
 490        struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 491        memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 492        ret->next = NULL;
 493        return ret;
 494}
 495
 496void free_refs(struct ref *ref)
 497{
 498        struct ref *next;
 499        while (ref) {
 500                next = ref->next;
 501                if (ref->peer_ref)
 502                        free(ref->peer_ref);
 503                free(ref);
 504                ref = next;
 505        }
 506}
 507
 508static int count_refspec_match(const char *pattern,
 509                               struct ref *refs,
 510                               struct ref **matched_ref)
 511{
 512        int patlen = strlen(pattern);
 513        struct ref *matched_weak = NULL;
 514        struct ref *matched = NULL;
 515        int weak_match = 0;
 516        int match = 0;
 517
 518        for (weak_match = match = 0; refs; refs = refs->next) {
 519                char *name = refs->name;
 520                int namelen = strlen(name);
 521
 522                if (!refname_match(pattern, name, ref_rev_parse_rules))
 523                        continue;
 524
 525                /* A match is "weak" if it is with refs outside
 526                 * heads or tags, and did not specify the pattern
 527                 * in full (e.g. "refs/remotes/origin/master") or at
 528                 * least from the toplevel (e.g. "remotes/origin/master");
 529                 * otherwise "git push $URL master" would result in
 530                 * ambiguity between remotes/origin/master and heads/master
 531                 * at the remote site.
 532                 */
 533                if (namelen != patlen &&
 534                    patlen != namelen - 5 &&
 535                    prefixcmp(name, "refs/heads/") &&
 536                    prefixcmp(name, "refs/tags/")) {
 537                        /* We want to catch the case where only weak
 538                         * matches are found and there are multiple
 539                         * matches, and where more than one strong
 540                         * matches are found, as ambiguous.  One
 541                         * strong match with zero or more weak matches
 542                         * are acceptable as a unique match.
 543                         */
 544                        matched_weak = refs;
 545                        weak_match++;
 546                }
 547                else {
 548                        matched = refs;
 549                        match++;
 550                }
 551        }
 552        if (!matched) {
 553                *matched_ref = matched_weak;
 554                return weak_match;
 555        }
 556        else {
 557                *matched_ref = matched;
 558                return match;
 559        }
 560}
 561
 562static void tail_link_ref(struct ref *ref, struct ref ***tail)
 563{
 564        **tail = ref;
 565        while (ref->next)
 566                ref = ref->next;
 567        *tail = &ref->next;
 568}
 569
 570static struct ref *try_explicit_object_name(const char *name)
 571{
 572        unsigned char sha1[20];
 573        struct ref *ref;
 574        int len;
 575
 576        if (!*name) {
 577                ref = alloc_ref(20);
 578                strcpy(ref->name, "(delete)");
 579                hashclr(ref->new_sha1);
 580                return ref;
 581        }
 582        if (get_sha1(name, sha1))
 583                return NULL;
 584        len = strlen(name) + 1;
 585        ref = alloc_ref(len);
 586        memcpy(ref->name, name, len);
 587        hashcpy(ref->new_sha1, sha1);
 588        return ref;
 589}
 590
 591static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 592{
 593        struct ref *ret;
 594        size_t len;
 595
 596        len = strlen(name) + 1;
 597        ret = alloc_ref(len);
 598        memcpy(ret->name, name, len);
 599        tail_link_ref(ret, tail);
 600        return ret;
 601}
 602
 603static int match_explicit(struct ref *src, struct ref *dst,
 604                          struct ref ***dst_tail,
 605                          struct refspec *rs,
 606                          int errs)
 607{
 608        struct ref *matched_src, *matched_dst;
 609
 610        const char *dst_value = rs->dst;
 611
 612        if (rs->pattern)
 613                return errs;
 614
 615        matched_src = matched_dst = NULL;
 616        switch (count_refspec_match(rs->src, src, &matched_src)) {
 617        case 1:
 618                break;
 619        case 0:
 620                /* The source could be in the get_sha1() format
 621                 * not a reference name.  :refs/other is a
 622                 * way to delete 'other' ref at the remote end.
 623                 */
 624                matched_src = try_explicit_object_name(rs->src);
 625                if (!matched_src)
 626                        error("src refspec %s does not match any.", rs->src);
 627                break;
 628        default:
 629                matched_src = NULL;
 630                error("src refspec %s matches more than one.", rs->src);
 631                break;
 632        }
 633
 634        if (!matched_src)
 635                errs = 1;
 636
 637        if (!dst_value) {
 638                if (!matched_src)
 639                        return errs;
 640                dst_value = matched_src->name;
 641        }
 642
 643        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 644        case 1:
 645                break;
 646        case 0:
 647                if (!memcmp(dst_value, "refs/", 5))
 648                        matched_dst = make_linked_ref(dst_value, dst_tail);
 649                else
 650                        error("dst refspec %s does not match any "
 651                              "existing ref on the remote and does "
 652                              "not start with refs/.", dst_value);
 653                break;
 654        default:
 655                matched_dst = NULL;
 656                error("dst refspec %s matches more than one.",
 657                      dst_value);
 658                break;
 659        }
 660        if (errs || !matched_dst)
 661                return 1;
 662        if (matched_dst->peer_ref) {
 663                errs = 1;
 664                error("dst ref %s receives from more than one src.",
 665                      matched_dst->name);
 666        }
 667        else {
 668                matched_dst->peer_ref = matched_src;
 669                matched_dst->force = rs->force;
 670        }
 671        return errs;
 672}
 673
 674static int match_explicit_refs(struct ref *src, struct ref *dst,
 675                               struct ref ***dst_tail, struct refspec *rs,
 676                               int rs_nr)
 677{
 678        int i, errs;
 679        for (i = errs = 0; i < rs_nr; i++)
 680                errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
 681        return -errs;
 682}
 683
 684static struct ref *find_ref_by_name(struct ref *list, const char *name)
 685{
 686        for ( ; list; list = list->next)
 687                if (!strcmp(list->name, name))
 688                        return list;
 689        return NULL;
 690}
 691
 692static const struct refspec *check_pattern_match(const struct refspec *rs,
 693                                                 int rs_nr,
 694                                                 const struct ref *src)
 695{
 696        int i;
 697        for (i = 0; i < rs_nr; i++) {
 698                if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
 699                        return rs + i;
 700        }
 701        return NULL;
 702}
 703
 704/*
 705 * Note. This is used only by "push"; refspec matching rules for
 706 * push and fetch are subtly different, so do not try to reuse it
 707 * without thinking.
 708 */
 709int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 710               int nr_refspec, char **refspec, int all)
 711{
 712        struct refspec *rs =
 713                parse_ref_spec(nr_refspec, (const char **) refspec);
 714
 715        if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
 716                return -1;
 717
 718        /* pick the remainder */
 719        for ( ; src; src = src->next) {
 720                struct ref *dst_peer;
 721                const struct refspec *pat = NULL;
 722                char *dst_name;
 723                if (src->peer_ref)
 724                        continue;
 725                if (nr_refspec) {
 726                        pat = check_pattern_match(rs, nr_refspec, src);
 727                        if (!pat)
 728                                continue;
 729                }
 730                else if (prefixcmp(src->name, "refs/heads/"))
 731                        /*
 732                         * "matching refs"; traditionally we pushed everything
 733                         * including refs outside refs/heads/ hierarchy, but
 734                         * that does not make much sense these days.
 735                         */
 736                        continue;
 737
 738                if (pat) {
 739                        const char *dst_side = pat->dst ? pat->dst : pat->src;
 740                        dst_name = xmalloc(strlen(dst_side) +
 741                                           strlen(src->name) -
 742                                           strlen(pat->src) + 2);
 743                        strcpy(dst_name, dst_side);
 744                        strcat(dst_name, src->name + strlen(pat->src));
 745                } else
 746                        dst_name = xstrdup(src->name);
 747                dst_peer = find_ref_by_name(dst, dst_name);
 748                if (dst_peer && dst_peer->peer_ref)
 749                        /* We're already sending something to this ref. */
 750                        goto free_name;
 751                if (!dst_peer && !nr_refspec && !all)
 752                        /* Remote doesn't have it, and we have no
 753                         * explicit pattern, and we don't have
 754                         * --all. */
 755                        goto free_name;
 756                if (!dst_peer) {
 757                        /* Create a new one and link it */
 758                        dst_peer = make_linked_ref(dst_name, dst_tail);
 759                        hashcpy(dst_peer->new_sha1, src->new_sha1);
 760                }
 761                dst_peer->peer_ref = src;
 762                if (pat)
 763                        dst_peer->force = pat->force;
 764        free_name:
 765                free(dst_name);
 766        }
 767        return 0;
 768}
 769
 770struct branch *branch_get(const char *name)
 771{
 772        struct branch *ret;
 773
 774        read_config();
 775        if (!name || !*name || !strcmp(name, "HEAD"))
 776                ret = current_branch;
 777        else
 778                ret = make_branch(name, 0);
 779        if (ret && ret->remote_name) {
 780                ret->remote = remote_get(ret->remote_name);
 781                if (ret->merge_nr) {
 782                        int i;
 783                        ret->merge = xcalloc(sizeof(*ret->merge),
 784                                             ret->merge_nr);
 785                        for (i = 0; i < ret->merge_nr; i++) {
 786                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
 787                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
 788                                remote_find_tracking(ret->remote,
 789                                                     ret->merge[i]);
 790                        }
 791                }
 792        }
 793        return ret;
 794}
 795
 796int branch_has_merge_config(struct branch *branch)
 797{
 798        return branch && !!branch->merge;
 799}
 800
 801int branch_merge_matches(struct branch *branch,
 802                                 int i,
 803                                 const char *refname)
 804{
 805        if (!branch || i < 0 || i >= branch->merge_nr)
 806                return 0;
 807        return ref_matches_abbrev(branch->merge[i]->src, refname);
 808}
 809
 810static struct ref *get_expanded_map(struct ref *remote_refs,
 811                                    const struct refspec *refspec)
 812{
 813        struct ref *ref;
 814        struct ref *ret = NULL;
 815        struct ref **tail = &ret;
 816
 817        int remote_prefix_len = strlen(refspec->src);
 818        int local_prefix_len = strlen(refspec->dst);
 819
 820        for (ref = remote_refs; ref; ref = ref->next) {
 821                if (strchr(ref->name, '^'))
 822                        continue; /* a dereference item */
 823                if (!prefixcmp(ref->name, refspec->src)) {
 824                        char *match;
 825                        struct ref *cpy = copy_ref(ref);
 826                        match = ref->name + remote_prefix_len;
 827
 828                        cpy->peer_ref = alloc_ref(local_prefix_len +
 829                                                  strlen(match) + 1);
 830                        sprintf(cpy->peer_ref->name, "%s%s",
 831                                refspec->dst, match);
 832                        if (refspec->force)
 833                                cpy->peer_ref->force = 1;
 834                        *tail = cpy;
 835                        tail = &cpy->next;
 836                }
 837        }
 838
 839        return ret;
 840}
 841
 842static struct ref *find_ref_by_name_abbrev(struct ref *refs, const char *name)
 843{
 844        struct ref *ref;
 845        for (ref = refs; ref; ref = ref->next) {
 846                if (ref_matches_abbrev(name, ref->name))
 847                        return ref;
 848        }
 849        return NULL;
 850}
 851
 852struct ref *get_remote_ref(struct ref *remote_refs, const char *name)
 853{
 854        struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
 855
 856        if (!ref)
 857                return NULL;
 858
 859        return copy_ref(ref);
 860}
 861
 862static struct ref *get_local_ref(const char *name)
 863{
 864        struct ref *ret;
 865        if (!name)
 866                return NULL;
 867
 868        if (!prefixcmp(name, "refs/")) {
 869                ret = alloc_ref(strlen(name) + 1);
 870                strcpy(ret->name, name);
 871                return ret;
 872        }
 873
 874        if (!prefixcmp(name, "heads/") ||
 875            !prefixcmp(name, "tags/") ||
 876            !prefixcmp(name, "remotes/")) {
 877                ret = alloc_ref(strlen(name) + 6);
 878                sprintf(ret->name, "refs/%s", name);
 879                return ret;
 880        }
 881
 882        ret = alloc_ref(strlen(name) + 12);
 883        sprintf(ret->name, "refs/heads/%s", name);
 884        return ret;
 885}
 886
 887int get_fetch_map(struct ref *remote_refs,
 888                  const struct refspec *refspec,
 889                  struct ref ***tail,
 890                  int missing_ok)
 891{
 892        struct ref *ref_map, *rm;
 893
 894        if (refspec->pattern) {
 895                ref_map = get_expanded_map(remote_refs, refspec);
 896        } else {
 897                const char *name = refspec->src[0] ? refspec->src : "HEAD";
 898
 899                ref_map = get_remote_ref(remote_refs, name);
 900                if (!missing_ok && !ref_map)
 901                        die("Couldn't find remote ref %s", name);
 902                if (ref_map) {
 903                        ref_map->peer_ref = get_local_ref(refspec->dst);
 904                        if (ref_map->peer_ref && refspec->force)
 905                                ref_map->peer_ref->force = 1;
 906                }
 907        }
 908
 909        for (rm = ref_map; rm; rm = rm->next) {
 910                if (rm->peer_ref && check_ref_format(rm->peer_ref->name + 5))
 911                        die("* refusing to create funny ref '%s' locally",
 912                            rm->peer_ref->name);
 913        }
 914
 915        if (ref_map)
 916                tail_link_ref(ref_map, tail);
 917
 918        return 0;
 919}