Andrew's git / gitweb.git / remote.c
?
remote.con commit diff --dirstat-by-file: count changed files, not lines (fd33777)
   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
   8static struct refspec s_tag_refspec = {
   9        0,
  10        1,
  11        0,
  12        "refs/tags/",
  13        "refs/tags/"
  14};
  15
  16const struct refspec *tag_refspec = &s_tag_refspec;
  17
  18struct counted_string {
  19        size_t len;
  20        const char *s;
  21};
  22struct rewrite {
  23        const char *base;
  24        size_t baselen;
  25        struct counted_string *instead_of;
  26        int instead_of_nr;
  27        int instead_of_alloc;
  28};
  29
  30static struct remote **remotes;
  31static int remotes_alloc;
  32static int remotes_nr;
  33
  34static struct branch **branches;
  35static int branches_alloc;
  36static int branches_nr;
  37
  38static struct branch *current_branch;
  39static const char *default_remote_name;
  40
  41static struct rewrite **rewrite;
  42static int rewrite_alloc;
  43static int rewrite_nr;
  44
  45#define BUF_SIZE (2048)
  46static char buffer[BUF_SIZE];
  47
  48static const char *alias_url(const char *url)
  49{
  50        int i, j;
  51        char *ret;
  52        struct counted_string *longest;
  53        int longest_i;
  54
  55        longest = NULL;
  56        longest_i = -1;
  57        for (i = 0; i < rewrite_nr; i++) {
  58                if (!rewrite[i])
  59                        continue;
  60                for (j = 0; j < rewrite[i]->instead_of_nr; j++) {
  61                        if (!prefixcmp(url, rewrite[i]->instead_of[j].s) &&
  62                            (!longest ||
  63                             longest->len < rewrite[i]->instead_of[j].len)) {
  64                                longest = &(rewrite[i]->instead_of[j]);
  65                                longest_i = i;
  66                        }
  67                }
  68        }
  69        if (!longest)
  70                return url;
  71
  72        ret = malloc(rewrite[longest_i]->baselen +
  73                     (strlen(url) - longest->len) + 1);
  74        strcpy(ret, rewrite[longest_i]->base);
  75        strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
  76        return ret;
  77}
  78
  79static void add_push_refspec(struct remote *remote, const char *ref)
  80{
  81        ALLOC_GROW(remote->push_refspec,
  82                   remote->push_refspec_nr + 1,
  83                   remote->push_refspec_alloc);
  84        remote->push_refspec[remote->push_refspec_nr++] = ref;
  85}
  86
  87static void add_fetch_refspec(struct remote *remote, const char *ref)
  88{
  89        ALLOC_GROW(remote->fetch_refspec,
  90                   remote->fetch_refspec_nr + 1,
  91                   remote->fetch_refspec_alloc);
  92        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
  93}
  94
  95static void add_url(struct remote *remote, const char *url)
  96{
  97        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
  98        remote->url[remote->url_nr++] = url;
  99}
 100
 101static void add_url_alias(struct remote *remote, const char *url)
 102{
 103        add_url(remote, alias_url(url));
 104}
 105
 106static struct remote *make_remote(const char *name, int len)
 107{
 108        struct remote *ret;
 109        int i;
 110
 111        for (i = 0; i < remotes_nr; i++) {
 112                if (len ? (!strncmp(name, remotes[i]->name, len) &&
 113                           !remotes[i]->name[len]) :
 114                    !strcmp(name, remotes[i]->name))
 115                        return remotes[i];
 116        }
 117
 118        ret = xcalloc(1, sizeof(struct remote));
 119        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 120        remotes[remotes_nr++] = ret;
 121        if (len)
 122                ret->name = xstrndup(name, len);
 123        else
 124                ret->name = xstrdup(name);
 125        return ret;
 126}
 127
 128static void add_merge(struct branch *branch, const char *name)
 129{
 130        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 131                   branch->merge_alloc);
 132        branch->merge_name[branch->merge_nr++] = name;
 133}
 134
 135static struct branch *make_branch(const char *name, int len)
 136{
 137        struct branch *ret;
 138        int i;
 139        char *refname;
 140
 141        for (i = 0; i < branches_nr; i++) {
 142                if (len ? (!strncmp(name, branches[i]->name, len) &&
 143                           !branches[i]->name[len]) :
 144                    !strcmp(name, branches[i]->name))
 145                        return branches[i];
 146        }
 147
 148        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 149        ret = xcalloc(1, sizeof(struct branch));
 150        branches[branches_nr++] = ret;
 151        if (len)
 152                ret->name = xstrndup(name, len);
 153        else
 154                ret->name = xstrdup(name);
 155        refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
 156        strcpy(refname, "refs/heads/");
 157        strcpy(refname + strlen("refs/heads/"), ret->name);
 158        ret->refname = refname;
 159
 160        return ret;
 161}
 162
 163static struct rewrite *make_rewrite(const char *base, int len)
 164{
 165        struct rewrite *ret;
 166        int i;
 167
 168        for (i = 0; i < rewrite_nr; i++) {
 169                if (len
 170                    ? (len == rewrite[i]->baselen &&
 171                       !strncmp(base, rewrite[i]->base, len))
 172                    : !strcmp(base, rewrite[i]->base))
 173                        return rewrite[i];
 174        }
 175
 176        ALLOC_GROW(rewrite, rewrite_nr + 1, rewrite_alloc);
 177        ret = xcalloc(1, sizeof(struct rewrite));
 178        rewrite[rewrite_nr++] = ret;
 179        if (len) {
 180                ret->base = xstrndup(base, len);
 181                ret->baselen = len;
 182        }
 183        else {
 184                ret->base = xstrdup(base);
 185                ret->baselen = strlen(base);
 186        }
 187        return ret;
 188}
 189
 190static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 191{
 192        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 193        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 194        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 195        rewrite->instead_of_nr++;
 196}
 197
 198static void read_remotes_file(struct remote *remote)
 199{
 200        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 201
 202        if (!f)
 203                return;
 204        while (fgets(buffer, BUF_SIZE, f)) {
 205                int value_list;
 206                char *s, *p;
 207
 208                if (!prefixcmp(buffer, "URL:")) {
 209                        value_list = 0;
 210                        s = buffer + 4;
 211                } else if (!prefixcmp(buffer, "Push:")) {
 212                        value_list = 1;
 213                        s = buffer + 5;
 214                } else if (!prefixcmp(buffer, "Pull:")) {
 215                        value_list = 2;
 216                        s = buffer + 5;
 217                } else
 218                        continue;
 219
 220                while (isspace(*s))
 221                        s++;
 222                if (!*s)
 223                        continue;
 224
 225                p = s + strlen(s);
 226                while (isspace(p[-1]))
 227                        *--p = 0;
 228
 229                switch (value_list) {
 230                case 0:
 231                        add_url_alias(remote, xstrdup(s));
 232                        break;
 233                case 1:
 234                        add_push_refspec(remote, xstrdup(s));
 235                        break;
 236                case 2:
 237                        add_fetch_refspec(remote, xstrdup(s));
 238                        break;
 239                }
 240        }
 241        fclose(f);
 242}
 243
 244static void read_branches_file(struct remote *remote)
 245{
 246        const char *slash = strchr(remote->name, '/');
 247        char *frag;
 248        struct strbuf branch;
 249        int n = slash ? slash - remote->name : 1000;
 250        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 251        char *s, *p;
 252        int len;
 253
 254        if (!f)
 255                return;
 256        s = fgets(buffer, BUF_SIZE, f);
 257        fclose(f);
 258        if (!s)
 259                return;
 260        while (isspace(*s))
 261                s++;
 262        if (!*s)
 263                return;
 264        p = s + strlen(s);
 265        while (isspace(p[-1]))
 266                *--p = 0;
 267        len = p - s;
 268        if (slash)
 269                len += strlen(slash);
 270        p = xmalloc(len + 1);
 271        strcpy(p, s);
 272        if (slash)
 273                strcat(p, slash);
 274
 275        /*
 276         * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 277         * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 278         * the partial URL obtained from the branches file plus
 279         * "/netdev-2.6" and does not store it in any tracking ref.
 280         * #branch specifier in the file is ignored.
 281         *
 282         * Otherwise, the branches file would have URL and optionally
 283         * #branch specified.  The "master" (or specified) branch is
 284         * fetched and stored in the local branch of the same name.
 285         */
 286        strbuf_init(&branch, 0);
 287        frag = strchr(p, '#');
 288        if (frag) {
 289                *(frag++) = '\0';
 290                strbuf_addf(&branch, "refs/heads/%s", frag);
 291        } else
 292                strbuf_addstr(&branch, "refs/heads/master");
 293        if (!slash) {
 294                strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 295        } else {
 296                strbuf_reset(&branch);
 297                strbuf_addstr(&branch, "HEAD:");
 298        }
 299        add_url_alias(remote, p);
 300        add_fetch_refspec(remote, strbuf_detach(&branch, 0));
 301        remote->fetch_tags = 1; /* always auto-follow */
 302}
 303
 304static int handle_config(const char *key, const char *value, void *cb)
 305{
 306        const char *name;
 307        const char *subkey;
 308        struct remote *remote;
 309        struct branch *branch;
 310        if (!prefixcmp(key, "branch.")) {
 311                name = key + 7;
 312                subkey = strrchr(name, '.');
 313                if (!subkey)
 314                        return 0;
 315                branch = make_branch(name, subkey - name);
 316                if (!strcmp(subkey, ".remote")) {
 317                        if (!value)
 318                                return config_error_nonbool(key);
 319                        branch->remote_name = xstrdup(value);
 320                        if (branch == current_branch)
 321                                default_remote_name = branch->remote_name;
 322                } else if (!strcmp(subkey, ".merge")) {
 323                        if (!value)
 324                                return config_error_nonbool(key);
 325                        add_merge(branch, xstrdup(value));
 326                }
 327                return 0;
 328        }
 329        if (!prefixcmp(key, "url.")) {
 330                struct rewrite *rewrite;
 331                name = key + 4;
 332                subkey = strrchr(name, '.');
 333                if (!subkey)
 334                        return 0;
 335                rewrite = make_rewrite(name, subkey - name);
 336                if (!strcmp(subkey, ".insteadof")) {
 337                        if (!value)
 338                                return config_error_nonbool(key);
 339                        add_instead_of(rewrite, xstrdup(value));
 340                }
 341        }
 342        if (prefixcmp(key,  "remote."))
 343                return 0;
 344        name = key + 7;
 345        subkey = strrchr(name, '.');
 346        if (!subkey)
 347                return error("Config with no key for remote %s", name);
 348        if (*subkey == '/') {
 349                warning("Config remote shorthand cannot begin with '/': %s", name);
 350                return 0;
 351        }
 352        remote = make_remote(name, subkey - name);
 353        if (!strcmp(subkey, ".mirror"))
 354                remote->mirror = git_config_bool(key, value);
 355        else if (!strcmp(subkey, ".skipdefaultupdate"))
 356                remote->skip_default_update = git_config_bool(key, value);
 357
 358        else if (!strcmp(subkey, ".url")) {
 359                const char *v;
 360                if (git_config_string(&v, key, value))
 361                        return -1;
 362                add_url(remote, v);
 363        } else if (!strcmp(subkey, ".push")) {
 364                const char *v;
 365                if (git_config_string(&v, key, value))
 366                        return -1;
 367                add_push_refspec(remote, v);
 368        } else if (!strcmp(subkey, ".fetch")) {
 369                const char *v;
 370                if (git_config_string(&v, key, value))
 371                        return -1;
 372                add_fetch_refspec(remote, v);
 373        } else if (!strcmp(subkey, ".receivepack")) {
 374                const char *v;
 375                if (git_config_string(&v, key, value))
 376                        return -1;
 377                if (!remote->receivepack)
 378                        remote->receivepack = v;
 379                else
 380                        error("more than one receivepack given, using the first");
 381        } else if (!strcmp(subkey, ".uploadpack")) {
 382                const char *v;
 383                if (git_config_string(&v, key, value))
 384                        return -1;
 385                if (!remote->uploadpack)
 386                        remote->uploadpack = v;
 387                else
 388                        error("more than one uploadpack given, using the first");
 389        } else if (!strcmp(subkey, ".tagopt")) {
 390                if (!strcmp(value, "--no-tags"))
 391                        remote->fetch_tags = -1;
 392        } else if (!strcmp(subkey, ".proxy")) {
 393                return git_config_string((const char **)&remote->http_proxy,
 394                                         key, value);
 395        }
 396        return 0;
 397}
 398
 399static void alias_all_urls(void)
 400{
 401        int i, j;
 402        for (i = 0; i < remotes_nr; i++) {
 403                if (!remotes[i])
 404                        continue;
 405                for (j = 0; j < remotes[i]->url_nr; j++) {
 406                        remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 407                }
 408        }
 409}
 410
 411static void read_config(void)
 412{
 413        unsigned char sha1[20];
 414        const char *head_ref;
 415        int flag;
 416        if (default_remote_name) // did this already
 417                return;
 418        default_remote_name = xstrdup("origin");
 419        current_branch = NULL;
 420        head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 421        if (head_ref && (flag & REF_ISSYMREF) &&
 422            !prefixcmp(head_ref, "refs/heads/")) {
 423                current_branch =
 424                        make_branch(head_ref + strlen("refs/heads/"), 0);
 425        }
 426        git_config(handle_config, NULL);
 427        alias_all_urls();
 428}
 429
 430/*
 431 * We need to make sure the tracking branches are well formed, but a
 432 * wildcard refspec in "struct refspec" must have a trailing slash. We
 433 * temporarily drop the trailing '/' while calling check_ref_format(),
 434 * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 435 * error return is Ok for a wildcard refspec.
 436 */
 437static int verify_refname(char *name, int is_glob)
 438{
 439        int result, len = -1;
 440
 441        if (is_glob) {
 442                len = strlen(name);
 443                assert(name[len - 1] == '/');
 444                name[len - 1] = '\0';
 445        }
 446        result = check_ref_format(name);
 447        if (is_glob)
 448                name[len - 1] = '/';
 449        return result;
 450}
 451
 452/*
 453 * This function frees a refspec array.
 454 * Warning: code paths should be checked to ensure that the src
 455 *          and dst pointers are always freeable pointers as well
 456 *          as the refspec pointer itself.
 457 */
 458void free_refspecs(struct refspec *refspec, int nr_refspec)
 459{
 460        int i;
 461
 462        if (!refspec)
 463                return;
 464
 465        for (i = 0; i < nr_refspec; i++) {
 466                free(refspec[i].src);
 467                free(refspec[i].dst);
 468        }
 469        free(refspec);
 470}
 471
 472static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 473{
 474        int i;
 475        int st;
 476        struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 477
 478        for (i = 0; i < nr_refspec; i++) {
 479                size_t llen;
 480                int is_glob;
 481                const char *lhs, *rhs;
 482
 483                llen = is_glob = 0;
 484
 485                lhs = refspec[i];
 486                if (*lhs == '+') {
 487                        rs[i].force = 1;
 488                        lhs++;
 489                }
 490
 491                rhs = strrchr(lhs, ':');
 492
 493                /*
 494                 * Before going on, special case ":" (or "+:") as a refspec
 495                 * for matching refs.
 496                 */
 497                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 498                        rs[i].matching = 1;
 499                        continue;
 500                }
 501
 502                if (rhs) {
 503                        size_t rlen = strlen(++rhs);
 504                        is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
 505                        rs[i].dst = xstrndup(rhs, rlen - is_glob);
 506                }
 507
 508                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 509                if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
 510                        if ((rhs && !is_glob) || (!rhs && fetch))
 511                                goto invalid;
 512                        is_glob = 1;
 513                        llen--;
 514                } else if (rhs && is_glob) {
 515                        goto invalid;
 516                }
 517
 518                rs[i].pattern = is_glob;
 519                rs[i].src = xstrndup(lhs, llen);
 520
 521                if (fetch) {
 522                        /*
 523                         * LHS
 524                         * - empty is allowed; it means HEAD.
 525                         * - otherwise it must be a valid looking ref.
 526                         */
 527                        if (!*rs[i].src)
 528                                ; /* empty is ok */
 529                        else {
 530                                st = verify_refname(rs[i].src, is_glob);
 531                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 532                                        goto invalid;
 533                        }
 534                        /*
 535                         * RHS
 536                         * - missing is ok, and is same as empty.
 537                         * - empty is ok; it means not to store.
 538                         * - otherwise it must be a valid looking ref.
 539                         */
 540                        if (!rs[i].dst) {
 541                                ; /* ok */
 542                        } else if (!*rs[i].dst) {
 543                                ; /* ok */
 544                        } else {
 545                                st = verify_refname(rs[i].dst, is_glob);
 546                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 547                                        goto invalid;
 548                        }
 549                } else {
 550                        /*
 551                         * LHS
 552                         * - empty is allowed; it means delete.
 553                         * - when wildcarded, it must be a valid looking ref.
 554                         * - otherwise, it must be an extended SHA-1, but
 555                         *   there is no existing way to validate this.
 556                         */
 557                        if (!*rs[i].src)
 558                                ; /* empty is ok */
 559                        else if (is_glob) {
 560                                st = verify_refname(rs[i].src, is_glob);
 561                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 562                                        goto invalid;
 563                        }
 564                        else
 565                                ; /* anything goes, for now */
 566                        /*
 567                         * RHS
 568                         * - missing is allowed, but LHS then must be a
 569                         *   valid looking ref.
 570                         * - empty is not allowed.
 571                         * - otherwise it must be a valid looking ref.
 572                         */
 573                        if (!rs[i].dst) {
 574                                st = verify_refname(rs[i].src, is_glob);
 575                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 576                                        goto invalid;
 577                        } else if (!*rs[i].dst) {
 578                                goto invalid;
 579                        } else {
 580                                st = verify_refname(rs[i].dst, is_glob);
 581                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 582                                        goto invalid;
 583                        }
 584                }
 585        }
 586        return rs;
 587
 588 invalid:
 589        if (verify) {
 590                /*
 591                 * nr_refspec must be greater than zero and i must be valid
 592                 * since it is only possible to reach this point from within
 593                 * the for loop above.
 594                 */
 595                free_refspecs(rs, i+1);
 596                return NULL;
 597        }
 598        die("Invalid refspec '%s'", refspec[i]);
 599}
 600
 601int valid_fetch_refspec(const char *fetch_refspec_str)
 602{
 603        const char *fetch_refspec[] = { fetch_refspec_str };
 604        struct refspec *refspec;
 605
 606        refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 607        free_refspecs(refspec, 1);
 608        return !!refspec;
 609}
 610
 611struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 612{
 613        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 614}
 615
 616struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 617{
 618        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 619}
 620
 621static int valid_remote_nick(const char *name)
 622{
 623        if (!name[0] || /* not empty */
 624            (name[0] == '.' && /* not "." */
 625             (!name[1] || /* not ".." */
 626              (name[1] == '.' && !name[2]))))
 627                return 0;
 628        return !strchr(name, '/'); /* no slash */
 629}
 630
 631struct remote *remote_get(const char *name)
 632{
 633        struct remote *ret;
 634
 635        read_config();
 636        if (!name)
 637                name = default_remote_name;
 638        ret = make_remote(name, 0);
 639        if (valid_remote_nick(name)) {
 640                if (!ret->url)
 641                        read_remotes_file(ret);
 642                if (!ret->url)
 643                        read_branches_file(ret);
 644        }
 645        if (!ret->url)
 646                add_url_alias(ret, name);
 647        if (!ret->url)
 648                return NULL;
 649        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 650        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 651        return ret;
 652}
 653
 654int for_each_remote(each_remote_fn fn, void *priv)
 655{
 656        int i, result = 0;
 657        read_config();
 658        for (i = 0; i < remotes_nr && !result; i++) {
 659                struct remote *r = remotes[i];
 660                if (!r)
 661                        continue;
 662                if (!r->fetch)
 663                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 664                                                       r->fetch_refspec);
 665                if (!r->push)
 666                        r->push = parse_push_refspec(r->push_refspec_nr,
 667                                                     r->push_refspec);
 668                result = fn(r, priv);
 669        }
 670        return result;
 671}
 672
 673void ref_remove_duplicates(struct ref *ref_map)
 674{
 675        struct ref **posn;
 676        struct ref *next;
 677        for (; ref_map; ref_map = ref_map->next) {
 678                if (!ref_map->peer_ref)
 679                        continue;
 680                posn = &ref_map->next;
 681                while (*posn) {
 682                        if ((*posn)->peer_ref &&
 683                            !strcmp((*posn)->peer_ref->name,
 684                                    ref_map->peer_ref->name)) {
 685                                if (strcmp((*posn)->name, ref_map->name))
 686                                        die("%s tracks both %s and %s",
 687                                            ref_map->peer_ref->name,
 688                                            (*posn)->name, ref_map->name);
 689                                next = (*posn)->next;
 690                                free((*posn)->peer_ref);
 691                                free(*posn);
 692                                *posn = next;
 693                        } else {
 694                                posn = &(*posn)->next;
 695                        }
 696                }
 697        }
 698}
 699
 700int remote_has_url(struct remote *remote, const char *url)
 701{
 702        int i;
 703        for (i = 0; i < remote->url_nr; i++) {
 704                if (!strcmp(remote->url[i], url))
 705                        return 1;
 706        }
 707        return 0;
 708}
 709
 710int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 711{
 712        int find_src = refspec->src == NULL;
 713        char *needle, **result;
 714        int i;
 715
 716        if (find_src) {
 717                if (!refspec->dst)
 718                        return error("find_tracking: need either src or dst");
 719                needle = refspec->dst;
 720                result = &refspec->src;
 721        } else {
 722                needle = refspec->src;
 723                result = &refspec->dst;
 724        }
 725
 726        for (i = 0; i < remote->fetch_refspec_nr; i++) {
 727                struct refspec *fetch = &remote->fetch[i];
 728                const char *key = find_src ? fetch->dst : fetch->src;
 729                const char *value = find_src ? fetch->src : fetch->dst;
 730                if (!fetch->dst)
 731                        continue;
 732                if (fetch->pattern) {
 733                        if (!prefixcmp(needle, key)) {
 734                                *result = xmalloc(strlen(value) +
 735                                                  strlen(needle) -
 736                                                  strlen(key) + 1);
 737                                strcpy(*result, value);
 738                                strcpy(*result + strlen(value),
 739                                       needle + strlen(key));
 740                                refspec->force = fetch->force;
 741                                return 0;
 742                        }
 743                } else if (!strcmp(needle, key)) {
 744                        *result = xstrdup(value);
 745                        refspec->force = fetch->force;
 746                        return 0;
 747                }
 748        }
 749        return -1;
 750}
 751
 752struct ref *alloc_ref(unsigned namelen)
 753{
 754        struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 755        memset(ret, 0, sizeof(struct ref) + namelen);
 756        return ret;
 757}
 758
 759struct ref *alloc_ref_from_str(const char* str)
 760{
 761        struct ref *ret = alloc_ref(strlen(str) + 1);
 762        strcpy(ret->name, str);
 763        return ret;
 764}
 765
 766static struct ref *copy_ref(const struct ref *ref)
 767{
 768        struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 769        memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 770        ret->next = NULL;
 771        return ret;
 772}
 773
 774struct ref *copy_ref_list(const struct ref *ref)
 775{
 776        struct ref *ret = NULL;
 777        struct ref **tail = &ret;
 778        while (ref) {
 779                *tail = copy_ref(ref);
 780                ref = ref->next;
 781                tail = &((*tail)->next);
 782        }
 783        return ret;
 784}
 785
 786void free_ref(struct ref *ref)
 787{
 788        if (!ref)
 789                return;
 790        free(ref->remote_status);
 791        free(ref->symref);
 792        free(ref);
 793}
 794
 795void free_refs(struct ref *ref)
 796{
 797        struct ref *next;
 798        while (ref) {
 799                next = ref->next;
 800                free(ref->peer_ref);
 801                free_ref(ref);
 802                ref = next;
 803        }
 804}
 805
 806static int count_refspec_match(const char *pattern,
 807                               struct ref *refs,
 808                               struct ref **matched_ref)
 809{
 810        int patlen = strlen(pattern);
 811        struct ref *matched_weak = NULL;
 812        struct ref *matched = NULL;
 813        int weak_match = 0;
 814        int match = 0;
 815
 816        for (weak_match = match = 0; refs; refs = refs->next) {
 817                char *name = refs->name;
 818                int namelen = strlen(name);
 819
 820                if (!refname_match(pattern, name, ref_rev_parse_rules))
 821                        continue;
 822
 823                /* A match is "weak" if it is with refs outside
 824                 * heads or tags, and did not specify the pattern
 825                 * in full (e.g. "refs/remotes/origin/master") or at
 826                 * least from the toplevel (e.g. "remotes/origin/master");
 827                 * otherwise "git push $URL master" would result in
 828                 * ambiguity between remotes/origin/master and heads/master
 829                 * at the remote site.
 830                 */
 831                if (namelen != patlen &&
 832                    patlen != namelen - 5 &&
 833                    prefixcmp(name, "refs/heads/") &&
 834                    prefixcmp(name, "refs/tags/")) {
 835                        /* We want to catch the case where only weak
 836                         * matches are found and there are multiple
 837                         * matches, and where more than one strong
 838                         * matches are found, as ambiguous.  One
 839                         * strong match with zero or more weak matches
 840                         * are acceptable as a unique match.
 841                         */
 842                        matched_weak = refs;
 843                        weak_match++;
 844                }
 845                else {
 846                        matched = refs;
 847                        match++;
 848                }
 849        }
 850        if (!matched) {
 851                *matched_ref = matched_weak;
 852                return weak_match;
 853        }
 854        else {
 855                *matched_ref = matched;
 856                return match;
 857        }
 858}
 859
 860static void tail_link_ref(struct ref *ref, struct ref ***tail)
 861{
 862        **tail = ref;
 863        while (ref->next)
 864                ref = ref->next;
 865        *tail = &ref->next;
 866}
 867
 868static struct ref *try_explicit_object_name(const char *name)
 869{
 870        unsigned char sha1[20];
 871        struct ref *ref;
 872
 873        if (!*name) {
 874                ref = alloc_ref(20);
 875                strcpy(ref->name, "(delete)");
 876                hashclr(ref->new_sha1);
 877                return ref;
 878        }
 879        if (get_sha1(name, sha1))
 880                return NULL;
 881        ref = alloc_ref_from_str(name);
 882        hashcpy(ref->new_sha1, sha1);
 883        return ref;
 884}
 885
 886static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 887{
 888        struct ref *ret = alloc_ref_from_str(name);
 889        tail_link_ref(ret, tail);
 890        return ret;
 891}
 892
 893static char *guess_ref(const char *name, struct ref *peer)
 894{
 895        struct strbuf buf = STRBUF_INIT;
 896        unsigned char sha1[20];
 897
 898        const char *r = resolve_ref(peer->name, sha1, 1, NULL);
 899        if (!r)
 900                return NULL;
 901
 902        if (!prefixcmp(r, "refs/heads/"))
 903                strbuf_addstr(&buf, "refs/heads/");
 904        else if (!prefixcmp(r, "refs/tags/"))
 905                strbuf_addstr(&buf, "refs/tags/");
 906        else
 907                return NULL;
 908
 909        strbuf_addstr(&buf, name);
 910        return strbuf_detach(&buf, NULL);
 911}
 912
 913static int match_explicit(struct ref *src, struct ref *dst,
 914                          struct ref ***dst_tail,
 915                          struct refspec *rs)
 916{
 917        struct ref *matched_src, *matched_dst;
 918
 919        const char *dst_value = rs->dst;
 920        char *dst_guess;
 921
 922        if (rs->pattern || rs->matching)
 923                return 0;
 924
 925        matched_src = matched_dst = NULL;
 926        switch (count_refspec_match(rs->src, src, &matched_src)) {
 927        case 1:
 928                break;
 929        case 0:
 930                /* The source could be in the get_sha1() format
 931                 * not a reference name.  :refs/other is a
 932                 * way to delete 'other' ref at the remote end.
 933                 */
 934                matched_src = try_explicit_object_name(rs->src);
 935                if (!matched_src)
 936                        return error("src refspec %s does not match any.", rs->src);
 937                break;
 938        default:
 939                return error("src refspec %s matches more than one.", rs->src);
 940        }
 941
 942        if (!dst_value) {
 943                unsigned char sha1[20];
 944                int flag;
 945
 946                dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 947                if (!dst_value ||
 948                    ((flag & REF_ISSYMREF) &&
 949                     prefixcmp(dst_value, "refs/heads/")))
 950                        die("%s cannot be resolved to branch.",
 951                            matched_src->name);
 952        }
 953
 954        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 955        case 1:
 956                break;
 957        case 0:
 958                if (!memcmp(dst_value, "refs/", 5))
 959                        matched_dst = make_linked_ref(dst_value, dst_tail);
 960                else if((dst_guess = guess_ref(dst_value, matched_src)))
 961                        matched_dst = make_linked_ref(dst_guess, dst_tail);
 962                else
 963                        error("unable to push to unqualified destination: %s\n"
 964                              "The destination refspec neither matches an "
 965                              "existing ref on the remote nor\n"
 966                              "begins with refs/, and we are unable to "
 967                              "guess a prefix based on the source ref.",
 968                              dst_value);
 969                break;
 970        default:
 971                matched_dst = NULL;
 972                error("dst refspec %s matches more than one.",
 973                      dst_value);
 974                break;
 975        }
 976        if (!matched_dst)
 977                return -1;
 978        if (matched_dst->peer_ref)
 979                return error("dst ref %s receives from more than one src.",
 980                      matched_dst->name);
 981        else {
 982                matched_dst->peer_ref = matched_src;
 983                matched_dst->force = rs->force;
 984        }
 985        return 0;
 986}
 987
 988static int match_explicit_refs(struct ref *src, struct ref *dst,
 989                               struct ref ***dst_tail, struct refspec *rs,
 990                               int rs_nr)
 991{
 992        int i, errs;
 993        for (i = errs = 0; i < rs_nr; i++)
 994                errs += match_explicit(src, dst, dst_tail, &rs[i]);
 995        return errs;
 996}
 997
 998static const struct refspec *check_pattern_match(const struct refspec *rs,
 999                                                 int rs_nr,
1000                                                 const struct ref *src)
1001{
1002        int i;
1003        int matching_refs = -1;
1004        for (i = 0; i < rs_nr; i++) {
1005                if (rs[i].matching &&
1006                    (matching_refs == -1 || rs[i].force)) {
1007                        matching_refs = i;
1008                        continue;
1009                }
1010
1011                if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
1012                        return rs + i;
1013        }
1014        if (matching_refs != -1)
1015                return rs + matching_refs;
1016        else
1017                return NULL;
1018}
1019
1020/*
1021 * Note. This is used only by "push"; refspec matching rules for
1022 * push and fetch are subtly different, so do not try to reuse it
1023 * without thinking.
1024 */
1025int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
1026               int nr_refspec, const char **refspec, int flags)
1027{
1028        struct refspec *rs;
1029        int send_all = flags & MATCH_REFS_ALL;
1030        int send_mirror = flags & MATCH_REFS_MIRROR;
1031        static const char *default_refspec[] = { ":", 0 };
1032
1033        if (!nr_refspec) {
1034                nr_refspec = 1;
1035                refspec = default_refspec;
1036        }
1037        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1038        if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
1039                return -1;
1040
1041        /* pick the remainder */
1042        for ( ; src; src = src->next) {
1043                struct ref *dst_peer;
1044                const struct refspec *pat = NULL;
1045                char *dst_name;
1046                if (src->peer_ref)
1047                        continue;
1048
1049                pat = check_pattern_match(rs, nr_refspec, src);
1050                if (!pat)
1051                        continue;
1052
1053                if (pat->matching) {
1054                        /*
1055                         * "matching refs"; traditionally we pushed everything
1056                         * including refs outside refs/heads/ hierarchy, but
1057                         * that does not make much sense these days.
1058                         */
1059                        if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1060                                continue;
1061                        dst_name = xstrdup(src->name);
1062
1063                } else {
1064                        const char *dst_side = pat->dst ? pat->dst : pat->src;
1065                        dst_name = xmalloc(strlen(dst_side) +
1066                                           strlen(src->name) -
1067                                           strlen(pat->src) + 2);
1068                        strcpy(dst_name, dst_side);
1069                        strcat(dst_name, src->name + strlen(pat->src));
1070                }
1071                dst_peer = find_ref_by_name(dst, dst_name);
1072                if (dst_peer) {
1073                        if (dst_peer->peer_ref)
1074                                /* We're already sending something to this ref. */
1075                                goto free_name;
1076
1077                } else {
1078                        if (pat->matching && !(send_all || send_mirror))
1079                                /*
1080                                 * Remote doesn't have it, and we have no
1081                                 * explicit pattern, and we don't have
1082                                 * --all nor --mirror.
1083                                 */
1084                                goto free_name;
1085
1086                        /* Create a new one and link it */
1087                        dst_peer = make_linked_ref(dst_name, dst_tail);
1088                        hashcpy(dst_peer->new_sha1, src->new_sha1);
1089                }
1090                dst_peer->peer_ref = src;
1091                dst_peer->force = pat->force;
1092        free_name:
1093                free(dst_name);
1094        }
1095        return 0;
1096}
1097
1098struct branch *branch_get(const char *name)
1099{
1100        struct branch *ret;
1101
1102        read_config();
1103        if (!name || !*name || !strcmp(name, "HEAD"))
1104                ret = current_branch;
1105        else
1106                ret = make_branch(name, 0);
1107        if (ret && ret->remote_name) {
1108                ret->remote = remote_get(ret->remote_name);
1109                if (ret->merge_nr) {
1110                        int i;
1111                        ret->merge = xcalloc(sizeof(*ret->merge),
1112                                             ret->merge_nr);
1113                        for (i = 0; i < ret->merge_nr; i++) {
1114                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1115                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1116                                remote_find_tracking(ret->remote,
1117                                                     ret->merge[i]);
1118                        }
1119                }
1120        }
1121        return ret;
1122}
1123
1124int branch_has_merge_config(struct branch *branch)
1125{
1126        return branch && !!branch->merge;
1127}
1128
1129int branch_merge_matches(struct branch *branch,
1130                                 int i,
1131                                 const char *refname)
1132{
1133        if (!branch || i < 0 || i >= branch->merge_nr)
1134                return 0;
1135        return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1136}
1137
1138static struct ref *get_expanded_map(const struct ref *remote_refs,
1139                                    const struct refspec *refspec)
1140{
1141        const struct ref *ref;
1142        struct ref *ret = NULL;
1143        struct ref **tail = &ret;
1144
1145        int remote_prefix_len = strlen(refspec->src);
1146        int local_prefix_len = strlen(refspec->dst);
1147
1148        for (ref = remote_refs; ref; ref = ref->next) {
1149                if (strchr(ref->name, '^'))
1150                        continue; /* a dereference item */
1151                if (!prefixcmp(ref->name, refspec->src)) {
1152                        const char *match;
1153                        struct ref *cpy = copy_ref(ref);
1154                        match = ref->name + remote_prefix_len;
1155
1156                        cpy->peer_ref = alloc_ref(local_prefix_len +
1157                                                  strlen(match) + 1);
1158                        sprintf(cpy->peer_ref->name, "%s%s",
1159                                refspec->dst, match);
1160                        if (refspec->force)
1161                                cpy->peer_ref->force = 1;
1162                        *tail = cpy;
1163                        tail = &cpy->next;
1164                }
1165        }
1166
1167        return ret;
1168}
1169
1170static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1171{
1172        const struct ref *ref;
1173        for (ref = refs; ref; ref = ref->next) {
1174                if (refname_match(name, ref->name, ref_fetch_rules))
1175                        return ref;
1176        }
1177        return NULL;
1178}
1179
1180struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1181{
1182        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1183
1184        if (!ref)
1185                return NULL;
1186
1187        return copy_ref(ref);
1188}
1189
1190static struct ref *get_local_ref(const char *name)
1191{
1192        struct ref *ret;
1193        if (!name)
1194                return NULL;
1195
1196        if (!prefixcmp(name, "refs/")) {
1197                return alloc_ref_from_str(name);
1198        }
1199
1200        if (!prefixcmp(name, "heads/") ||
1201            !prefixcmp(name, "tags/") ||
1202            !prefixcmp(name, "remotes/")) {
1203                ret = alloc_ref(strlen(name) + 6);
1204                sprintf(ret->name, "refs/%s", name);
1205                return ret;
1206        }
1207
1208        ret = alloc_ref(strlen(name) + 12);
1209        sprintf(ret->name, "refs/heads/%s", name);
1210        return ret;
1211}
1212
1213int get_fetch_map(const struct ref *remote_refs,
1214                  const struct refspec *refspec,
1215                  struct ref ***tail,
1216                  int missing_ok)
1217{
1218        struct ref *ref_map, **rmp;
1219
1220        if (refspec->pattern) {
1221                ref_map = get_expanded_map(remote_refs, refspec);
1222        } else {
1223                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1224
1225                ref_map = get_remote_ref(remote_refs, name);
1226                if (!missing_ok && !ref_map)
1227                        die("Couldn't find remote ref %s", name);
1228                if (ref_map) {
1229                        ref_map->peer_ref = get_local_ref(refspec->dst);
1230                        if (ref_map->peer_ref && refspec->force)
1231                                ref_map->peer_ref->force = 1;
1232                }
1233        }
1234
1235        for (rmp = &ref_map; *rmp; ) {
1236                if ((*rmp)->peer_ref) {
1237                        int st = check_ref_format((*rmp)->peer_ref->name + 5);
1238                        if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1239                                struct ref *ignore = *rmp;
1240                                error("* Ignoring funny ref '%s' locally",
1241                                      (*rmp)->peer_ref->name);
1242                                *rmp = (*rmp)->next;
1243                                free(ignore->peer_ref);
1244                                free(ignore);
1245                                continue;
1246                        }
1247                }
1248                rmp = &((*rmp)->next);
1249        }
1250
1251        if (ref_map)
1252                tail_link_ref(ref_map, tail);
1253
1254        return 0;
1255}
1256
1257int resolve_remote_symref(struct ref *ref, struct ref *list)
1258{
1259        if (!ref->symref)
1260                return 0;
1261        for (; list; list = list->next)
1262                if (!strcmp(ref->symref, list->name)) {
1263                        hashcpy(ref->old_sha1, list->old_sha1);
1264                        return 0;
1265                }
1266        return 1;
1267}
1268
1269/*
1270 * Return true if there is anything to report, otherwise false.
1271 */
1272int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1273{
1274        unsigned char sha1[20];
1275        struct commit *ours, *theirs;
1276        char symmetric[84];
1277        struct rev_info revs;
1278        const char *rev_argv[10], *base;
1279        int rev_argc;
1280
1281        /*
1282         * Nothing to report unless we are marked to build on top of
1283         * somebody else.
1284         */
1285        if (!branch ||
1286            !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1287                return 0;
1288
1289        /*
1290         * If what we used to build on no longer exists, there is
1291         * nothing to report.
1292         */
1293        base = branch->merge[0]->dst;
1294        if (!resolve_ref(base, sha1, 1, NULL))
1295                return 0;
1296        theirs = lookup_commit(sha1);
1297        if (!theirs)
1298                return 0;
1299
1300        if (!resolve_ref(branch->refname, sha1, 1, NULL))
1301                return 0;
1302        ours = lookup_commit(sha1);
1303        if (!ours)
1304                return 0;
1305
1306        /* are we the same? */
1307        if (theirs == ours)
1308                return 0;
1309
1310        /* Run "rev-list --left-right ours...theirs" internally... */
1311        rev_argc = 0;
1312        rev_argv[rev_argc++] = NULL;
1313        rev_argv[rev_argc++] = "--left-right";
1314        rev_argv[rev_argc++] = symmetric;
1315        rev_argv[rev_argc++] = "--";
1316        rev_argv[rev_argc] = NULL;
1317
1318        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1319        strcpy(symmetric + 40, "...");
1320        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1321
1322        init_revisions(&revs, NULL);
1323        setup_revisions(rev_argc, rev_argv, &revs, NULL);
1324        prepare_revision_walk(&revs);
1325
1326        /* ... and count the commits on each side. */
1327        *num_ours = 0;
1328        *num_theirs = 0;
1329        while (1) {
1330                struct commit *c = get_revision(&revs);
1331                if (!c)
1332                        break;
1333                if (c->object.flags & SYMMETRIC_LEFT)
1334                        (*num_ours)++;
1335                else
1336                        (*num_theirs)++;
1337        }
1338
1339        /* clear object flags smudged by the above traversal */
1340        clear_commit_marks(ours, ALL_REV_FLAGS);
1341        clear_commit_marks(theirs, ALL_REV_FLAGS);
1342        return 1;
1343}
1344
1345/*
1346 * Return true when there is anything to report, otherwise false.
1347 */
1348int format_tracking_info(struct branch *branch, struct strbuf *sb)
1349{
1350        int num_ours, num_theirs;
1351        const char *base;
1352
1353        if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1354                return 0;
1355
1356        base = branch->merge[0]->dst;
1357        if (!prefixcmp(base, "refs/remotes/")) {
1358                base += strlen("refs/remotes/");
1359        }
1360        if (!num_theirs)
1361                strbuf_addf(sb, "Your branch is ahead of '%s' "
1362                            "by %d commit%s.\n",
1363                            base, num_ours, (num_ours == 1) ? "" : "s");
1364        else if (!num_ours)
1365                strbuf_addf(sb, "Your branch is behind '%s' "
1366                            "by %d commit%s, "
1367                            "and can be fast-forwarded.\n",
1368                            base, num_theirs, (num_theirs == 1) ? "" : "s");
1369        else
1370                strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1371                            "and have %d and %d different commit(s) each, "
1372                            "respectively.\n",
1373                            base, num_ours, num_theirs);
1374        return 1;
1375}