remote.con commit Merge branch 'mg/lib-gpg-ro-safety' (7654ca6)
   1#include "cache.h"
   2#include "remote.h"
   3#include "refs.h"
   4#include "commit.h"
   5#include "diff.h"
   6#include "revision.h"
   7#include "dir.h"
   8#include "tag.h"
   9#include "string-list.h"
  10#include "mergesort.h"
  11
  12enum map_direction { FROM_SRC, FROM_DST };
  13
  14static struct refspec s_tag_refspec = {
  15        0,
  16        1,
  17        0,
  18        0,
  19        "refs/tags/*",
  20        "refs/tags/*"
  21};
  22
  23const struct refspec *tag_refspec = &s_tag_refspec;
  24
  25struct counted_string {
  26        size_t len;
  27        const char *s;
  28};
  29struct rewrite {
  30        const char *base;
  31        size_t baselen;
  32        struct counted_string *instead_of;
  33        int instead_of_nr;
  34        int instead_of_alloc;
  35};
  36struct rewrites {
  37        struct rewrite **rewrite;
  38        int rewrite_alloc;
  39        int rewrite_nr;
  40};
  41
  42static struct remote **remotes;
  43static int remotes_alloc;
  44static int remotes_nr;
  45static struct hashmap remotes_hash;
  46
  47static struct branch **branches;
  48static int branches_alloc;
  49static int branches_nr;
  50
  51static struct branch *current_branch;
  52static const char *default_remote_name;
  53static const char *branch_pushremote_name;
  54static const char *pushremote_name;
  55static int explicit_default_remote_name;
  56
  57static struct rewrites rewrites;
  58static struct rewrites rewrites_push;
  59
  60#define BUF_SIZE (2048)
  61static char buffer[BUF_SIZE];
  62
  63static int valid_remote(const struct remote *remote)
  64{
  65        return (!!remote->url) || (!!remote->foreign_vcs);
  66}
  67
  68static const char *alias_url(const char *url, struct rewrites *r)
  69{
  70        int i, j;
  71        char *ret;
  72        struct counted_string *longest;
  73        int longest_i;
  74
  75        longest = NULL;
  76        longest_i = -1;
  77        for (i = 0; i < r->rewrite_nr; i++) {
  78                if (!r->rewrite[i])
  79                        continue;
  80                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  81                        if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  82                            (!longest ||
  83                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  84                                longest = &(r->rewrite[i]->instead_of[j]);
  85                                longest_i = i;
  86                        }
  87                }
  88        }
  89        if (!longest)
  90                return url;
  91
  92        ret = xmalloc(r->rewrite[longest_i]->baselen +
  93                     (strlen(url) - longest->len) + 1);
  94        strcpy(ret, r->rewrite[longest_i]->base);
  95        strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  96        return ret;
  97}
  98
  99static void add_push_refspec(struct remote *remote, const char *ref)
 100{
 101        ALLOC_GROW(remote->push_refspec,
 102                   remote->push_refspec_nr + 1,
 103                   remote->push_refspec_alloc);
 104        remote->push_refspec[remote->push_refspec_nr++] = ref;
 105}
 106
 107static void add_fetch_refspec(struct remote *remote, const char *ref)
 108{
 109        ALLOC_GROW(remote->fetch_refspec,
 110                   remote->fetch_refspec_nr + 1,
 111                   remote->fetch_refspec_alloc);
 112        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 113}
 114
 115static void add_url(struct remote *remote, const char *url)
 116{
 117        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 118        remote->url[remote->url_nr++] = url;
 119}
 120
 121static void add_pushurl(struct remote *remote, const char *pushurl)
 122{
 123        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 124        remote->pushurl[remote->pushurl_nr++] = pushurl;
 125}
 126
 127static void add_pushurl_alias(struct remote *remote, const char *url)
 128{
 129        const char *pushurl = alias_url(url, &rewrites_push);
 130        if (pushurl != url)
 131                add_pushurl(remote, pushurl);
 132}
 133
 134static void add_url_alias(struct remote *remote, const char *url)
 135{
 136        add_url(remote, alias_url(url, &rewrites));
 137        add_pushurl_alias(remote, url);
 138}
 139
 140struct remotes_hash_key {
 141        const char *str;
 142        int len;
 143};
 144
 145static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
 146{
 147        if (key)
 148                return strncmp(a->name, key->str, key->len) || a->name[key->len];
 149        else
 150                return strcmp(a->name, b->name);
 151}
 152
 153static inline void init_remotes_hash(void)
 154{
 155        if (!remotes_hash.cmpfn)
 156                hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
 157}
 158
 159static struct remote *make_remote(const char *name, int len)
 160{
 161        struct remote *ret, *replaced;
 162        struct remotes_hash_key lookup;
 163        struct hashmap_entry lookup_entry;
 164
 165        if (!len)
 166                len = strlen(name);
 167
 168        init_remotes_hash();
 169        lookup.str = name;
 170        lookup.len = len;
 171        hashmap_entry_init(&lookup_entry, memhash(name, len));
 172
 173        if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 174                return ret;
 175
 176        ret = xcalloc(1, sizeof(struct remote));
 177        ret->prune = -1;  /* unspecified */
 178        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 179        remotes[remotes_nr++] = ret;
 180        ret->name = xstrndup(name, len);
 181
 182        hashmap_entry_init(ret, lookup_entry.hash);
 183        replaced = hashmap_put(&remotes_hash, ret);
 184        assert(replaced == NULL);  /* no previous entry overwritten */
 185        return ret;
 186}
 187
 188static void add_merge(struct branch *branch, const char *name)
 189{
 190        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 191                   branch->merge_alloc);
 192        branch->merge_name[branch->merge_nr++] = name;
 193}
 194
 195static struct branch *make_branch(const char *name, int len)
 196{
 197        struct branch *ret;
 198        int i;
 199
 200        for (i = 0; i < branches_nr; i++) {
 201                if (len ? (!strncmp(name, branches[i]->name, len) &&
 202                           !branches[i]->name[len]) :
 203                    !strcmp(name, branches[i]->name))
 204                        return branches[i];
 205        }
 206
 207        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 208        ret = xcalloc(1, sizeof(struct branch));
 209        branches[branches_nr++] = ret;
 210        if (len)
 211                ret->name = xstrndup(name, len);
 212        else
 213                ret->name = xstrdup(name);
 214        ret->refname = xstrfmt("refs/heads/%s", ret->name);
 215
 216        return ret;
 217}
 218
 219static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 220{
 221        struct rewrite *ret;
 222        int i;
 223
 224        for (i = 0; i < r->rewrite_nr; i++) {
 225                if (len
 226                    ? (len == r->rewrite[i]->baselen &&
 227                       !strncmp(base, r->rewrite[i]->base, len))
 228                    : !strcmp(base, r->rewrite[i]->base))
 229                        return r->rewrite[i];
 230        }
 231
 232        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 233        ret = xcalloc(1, sizeof(struct rewrite));
 234        r->rewrite[r->rewrite_nr++] = ret;
 235        if (len) {
 236                ret->base = xstrndup(base, len);
 237                ret->baselen = len;
 238        }
 239        else {
 240                ret->base = xstrdup(base);
 241                ret->baselen = strlen(base);
 242        }
 243        return ret;
 244}
 245
 246static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 247{
 248        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 249        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 250        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 251        rewrite->instead_of_nr++;
 252}
 253
 254static void read_remotes_file(struct remote *remote)
 255{
 256        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 257
 258        if (!f)
 259                return;
 260        remote->origin = REMOTE_REMOTES;
 261        while (fgets(buffer, BUF_SIZE, f)) {
 262                int value_list;
 263                char *s, *p;
 264
 265                if (starts_with(buffer, "URL:")) {
 266                        value_list = 0;
 267                        s = buffer + 4;
 268                } else if (starts_with(buffer, "Push:")) {
 269                        value_list = 1;
 270                        s = buffer + 5;
 271                } else if (starts_with(buffer, "Pull:")) {
 272                        value_list = 2;
 273                        s = buffer + 5;
 274                } else
 275                        continue;
 276
 277                while (isspace(*s))
 278                        s++;
 279                if (!*s)
 280                        continue;
 281
 282                p = s + strlen(s);
 283                while (isspace(p[-1]))
 284                        *--p = 0;
 285
 286                switch (value_list) {
 287                case 0:
 288                        add_url_alias(remote, xstrdup(s));
 289                        break;
 290                case 1:
 291                        add_push_refspec(remote, xstrdup(s));
 292                        break;
 293                case 2:
 294                        add_fetch_refspec(remote, xstrdup(s));
 295                        break;
 296                }
 297        }
 298        fclose(f);
 299}
 300
 301static void read_branches_file(struct remote *remote)
 302{
 303        char *frag;
 304        struct strbuf branch = STRBUF_INIT;
 305        int n = 1000;
 306        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 307        char *s, *p;
 308        int len;
 309
 310        if (!f)
 311                return;
 312        s = fgets(buffer, BUF_SIZE, f);
 313        fclose(f);
 314        if (!s)
 315                return;
 316        while (isspace(*s))
 317                s++;
 318        if (!*s)
 319                return;
 320        remote->origin = REMOTE_BRANCHES;
 321        p = s + strlen(s);
 322        while (isspace(p[-1]))
 323                *--p = 0;
 324        len = p - s;
 325        p = xmalloc(len + 1);
 326        strcpy(p, s);
 327
 328        /*
 329         * The branches file would have URL and optionally
 330         * #branch specified.  The "master" (or specified) branch is
 331         * fetched and stored in the local branch of the same name.
 332         */
 333        frag = strchr(p, '#');
 334        if (frag) {
 335                *(frag++) = '\0';
 336                strbuf_addf(&branch, "refs/heads/%s", frag);
 337        } else
 338                strbuf_addstr(&branch, "refs/heads/master");
 339
 340        strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 341        add_url_alias(remote, p);
 342        add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 343        /*
 344         * Cogito compatible push: push current HEAD to remote #branch
 345         * (master if missing)
 346         */
 347        strbuf_init(&branch, 0);
 348        strbuf_addstr(&branch, "HEAD");
 349        if (frag)
 350                strbuf_addf(&branch, ":refs/heads/%s", frag);
 351        else
 352                strbuf_addstr(&branch, ":refs/heads/master");
 353        add_push_refspec(remote, strbuf_detach(&branch, NULL));
 354        remote->fetch_tags = 1; /* always auto-follow */
 355}
 356
 357static int handle_config(const char *key, const char *value, void *cb)
 358{
 359        const char *name;
 360        const char *subkey;
 361        struct remote *remote;
 362        struct branch *branch;
 363        if (starts_with(key, "branch.")) {
 364                name = key + 7;
 365                subkey = strrchr(name, '.');
 366                if (!subkey)
 367                        return 0;
 368                branch = make_branch(name, subkey - name);
 369                if (!strcmp(subkey, ".remote")) {
 370                        if (git_config_string(&branch->remote_name, key, value))
 371                                return -1;
 372                        if (branch == current_branch) {
 373                                default_remote_name = branch->remote_name;
 374                                explicit_default_remote_name = 1;
 375                        }
 376                } else if (!strcmp(subkey, ".pushremote")) {
 377                        if (branch == current_branch)
 378                                if (git_config_string(&branch_pushremote_name, key, value))
 379                                        return -1;
 380                } else if (!strcmp(subkey, ".merge")) {
 381                        if (!value)
 382                                return config_error_nonbool(key);
 383                        add_merge(branch, xstrdup(value));
 384                }
 385                return 0;
 386        }
 387        if (starts_with(key, "url.")) {
 388                struct rewrite *rewrite;
 389                name = key + 4;
 390                subkey = strrchr(name, '.');
 391                if (!subkey)
 392                        return 0;
 393                if (!strcmp(subkey, ".insteadof")) {
 394                        rewrite = make_rewrite(&rewrites, name, subkey - name);
 395                        if (!value)
 396                                return config_error_nonbool(key);
 397                        add_instead_of(rewrite, xstrdup(value));
 398                } else if (!strcmp(subkey, ".pushinsteadof")) {
 399                        rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 400                        if (!value)
 401                                return config_error_nonbool(key);
 402                        add_instead_of(rewrite, xstrdup(value));
 403                }
 404        }
 405
 406        if (!starts_with(key,  "remote."))
 407                return 0;
 408        name = key + 7;
 409
 410        /* Handle remote.* variables */
 411        if (!strcmp(name, "pushdefault"))
 412                return git_config_string(&pushremote_name, key, value);
 413
 414        /* Handle remote.<name>.* variables */
 415        if (*name == '/') {
 416                warning("Config remote shorthand cannot begin with '/': %s",
 417                        name);
 418                return 0;
 419        }
 420        subkey = strrchr(name, '.');
 421        if (!subkey)
 422                return 0;
 423        remote = make_remote(name, subkey - name);
 424        remote->origin = REMOTE_CONFIG;
 425        if (!strcmp(subkey, ".mirror"))
 426                remote->mirror = git_config_bool(key, value);
 427        else if (!strcmp(subkey, ".skipdefaultupdate"))
 428                remote->skip_default_update = git_config_bool(key, value);
 429        else if (!strcmp(subkey, ".skipfetchall"))
 430                remote->skip_default_update = git_config_bool(key, value);
 431        else if (!strcmp(subkey, ".prune"))
 432                remote->prune = git_config_bool(key, value);
 433        else if (!strcmp(subkey, ".url")) {
 434                const char *v;
 435                if (git_config_string(&v, key, value))
 436                        return -1;
 437                add_url(remote, v);
 438        } else if (!strcmp(subkey, ".pushurl")) {
 439                const char *v;
 440                if (git_config_string(&v, key, value))
 441                        return -1;
 442                add_pushurl(remote, v);
 443        } else if (!strcmp(subkey, ".push")) {
 444                const char *v;
 445                if (git_config_string(&v, key, value))
 446                        return -1;
 447                add_push_refspec(remote, v);
 448        } else if (!strcmp(subkey, ".fetch")) {
 449                const char *v;
 450                if (git_config_string(&v, key, value))
 451                        return -1;
 452                add_fetch_refspec(remote, v);
 453        } else if (!strcmp(subkey, ".receivepack")) {
 454                const char *v;
 455                if (git_config_string(&v, key, value))
 456                        return -1;
 457                if (!remote->receivepack)
 458                        remote->receivepack = v;
 459                else
 460                        error("more than one receivepack given, using the first");
 461        } else if (!strcmp(subkey, ".uploadpack")) {
 462                const char *v;
 463                if (git_config_string(&v, key, value))
 464                        return -1;
 465                if (!remote->uploadpack)
 466                        remote->uploadpack = v;
 467                else
 468                        error("more than one uploadpack given, using the first");
 469        } else if (!strcmp(subkey, ".tagopt")) {
 470                if (!strcmp(value, "--no-tags"))
 471                        remote->fetch_tags = -1;
 472                else if (!strcmp(value, "--tags"))
 473                        remote->fetch_tags = 2;
 474        } else if (!strcmp(subkey, ".proxy")) {
 475                return git_config_string((const char **)&remote->http_proxy,
 476                                         key, value);
 477        } else if (!strcmp(subkey, ".vcs")) {
 478                return git_config_string(&remote->foreign_vcs, key, value);
 479        }
 480        return 0;
 481}
 482
 483static void alias_all_urls(void)
 484{
 485        int i, j;
 486        for (i = 0; i < remotes_nr; i++) {
 487                int add_pushurl_aliases;
 488                if (!remotes[i])
 489                        continue;
 490                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 491                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 492                }
 493                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 494                for (j = 0; j < remotes[i]->url_nr; j++) {
 495                        if (add_pushurl_aliases)
 496                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 497                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 498                }
 499        }
 500}
 501
 502static void read_config(void)
 503{
 504        unsigned char sha1[20];
 505        const char *head_ref;
 506        int flag;
 507        if (default_remote_name) /* did this already */
 508                return;
 509        default_remote_name = "origin";
 510        current_branch = NULL;
 511        head_ref = resolve_ref_unsafe("HEAD", 0, sha1, &flag);
 512        if (head_ref && (flag & REF_ISSYMREF) &&
 513            skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 514                current_branch = make_branch(head_ref, 0);
 515        }
 516        git_config(handle_config, NULL);
 517        if (branch_pushremote_name) {
 518                free((char *)pushremote_name);
 519                pushremote_name = branch_pushremote_name;
 520        }
 521        alias_all_urls();
 522}
 523
 524/*
 525 * This function frees a refspec array.
 526 * Warning: code paths should be checked to ensure that the src
 527 *          and dst pointers are always freeable pointers as well
 528 *          as the refspec pointer itself.
 529 */
 530static void free_refspecs(struct refspec *refspec, int nr_refspec)
 531{
 532        int i;
 533
 534        if (!refspec)
 535                return;
 536
 537        for (i = 0; i < nr_refspec; i++) {
 538                free(refspec[i].src);
 539                free(refspec[i].dst);
 540        }
 541        free(refspec);
 542}
 543
 544static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 545{
 546        int i;
 547        struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 548
 549        for (i = 0; i < nr_refspec; i++) {
 550                size_t llen;
 551                int is_glob;
 552                const char *lhs, *rhs;
 553                int flags;
 554
 555                is_glob = 0;
 556
 557                lhs = refspec[i];
 558                if (*lhs == '+') {
 559                        rs[i].force = 1;
 560                        lhs++;
 561                }
 562
 563                rhs = strrchr(lhs, ':');
 564
 565                /*
 566                 * Before going on, special case ":" (or "+:") as a refspec
 567                 * for pushing matching refs.
 568                 */
 569                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 570                        rs[i].matching = 1;
 571                        continue;
 572                }
 573
 574                if (rhs) {
 575                        size_t rlen = strlen(++rhs);
 576                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 577                        rs[i].dst = xstrndup(rhs, rlen);
 578                }
 579
 580                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 581                if (1 <= llen && memchr(lhs, '*', llen)) {
 582                        if ((rhs && !is_glob) || (!rhs && fetch))
 583                                goto invalid;
 584                        is_glob = 1;
 585                } else if (rhs && is_glob) {
 586                        goto invalid;
 587                }
 588
 589                rs[i].pattern = is_glob;
 590                rs[i].src = xstrndup(lhs, llen);
 591                flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 592
 593                if (fetch) {
 594                        unsigned char unused[40];
 595
 596                        /* LHS */
 597                        if (!*rs[i].src)
 598                                ; /* empty is ok; it means "HEAD" */
 599                        else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 600                                rs[i].exact_sha1 = 1; /* ok */
 601                        else if (!check_refname_format(rs[i].src, flags))
 602                                ; /* valid looking ref is ok */
 603                        else
 604                                goto invalid;
 605                        /* RHS */
 606                        if (!rs[i].dst)
 607                                ; /* missing is ok; it is the same as empty */
 608                        else if (!*rs[i].dst)
 609                                ; /* empty is ok; it means "do not store" */
 610                        else if (!check_refname_format(rs[i].dst, flags))
 611                                ; /* valid looking ref is ok */
 612                        else
 613                                goto invalid;
 614                } else {
 615                        /*
 616                         * LHS
 617                         * - empty is allowed; it means delete.
 618                         * - when wildcarded, it must be a valid looking ref.
 619                         * - otherwise, it must be an extended SHA-1, but
 620                         *   there is no existing way to validate this.
 621                         */
 622                        if (!*rs[i].src)
 623                                ; /* empty is ok */
 624                        else if (is_glob) {
 625                                if (check_refname_format(rs[i].src, flags))
 626                                        goto invalid;
 627                        }
 628                        else
 629                                ; /* anything goes, for now */
 630                        /*
 631                         * RHS
 632                         * - missing is allowed, but LHS then must be a
 633                         *   valid looking ref.
 634                         * - empty is not allowed.
 635                         * - otherwise it must be a valid looking ref.
 636                         */
 637                        if (!rs[i].dst) {
 638                                if (check_refname_format(rs[i].src, flags))
 639                                        goto invalid;
 640                        } else if (!*rs[i].dst) {
 641                                goto invalid;
 642                        } else {
 643                                if (check_refname_format(rs[i].dst, flags))
 644                                        goto invalid;
 645                        }
 646                }
 647        }
 648        return rs;
 649
 650 invalid:
 651        if (verify) {
 652                /*
 653                 * nr_refspec must be greater than zero and i must be valid
 654                 * since it is only possible to reach this point from within
 655                 * the for loop above.
 656                 */
 657                free_refspecs(rs, i+1);
 658                return NULL;
 659        }
 660        die("Invalid refspec '%s'", refspec[i]);
 661}
 662
 663int valid_fetch_refspec(const char *fetch_refspec_str)
 664{
 665        struct refspec *refspec;
 666
 667        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 668        free_refspecs(refspec, 1);
 669        return !!refspec;
 670}
 671
 672struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 673{
 674        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 675}
 676
 677static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 678{
 679        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 680}
 681
 682void free_refspec(int nr_refspec, struct refspec *refspec)
 683{
 684        int i;
 685        for (i = 0; i < nr_refspec; i++) {
 686                free(refspec[i].src);
 687                free(refspec[i].dst);
 688        }
 689        free(refspec);
 690}
 691
 692static int valid_remote_nick(const char *name)
 693{
 694        if (!name[0] || is_dot_or_dotdot(name))
 695                return 0;
 696        return !strchr(name, '/'); /* no slash */
 697}
 698
 699static struct remote *remote_get_1(const char *name, const char *pushremote_name)
 700{
 701        struct remote *ret;
 702        int name_given = 0;
 703
 704        if (name)
 705                name_given = 1;
 706        else {
 707                if (pushremote_name) {
 708                        name = pushremote_name;
 709                        name_given = 1;
 710                } else {
 711                        name = default_remote_name;
 712                        name_given = explicit_default_remote_name;
 713                }
 714        }
 715
 716        ret = make_remote(name, 0);
 717        if (valid_remote_nick(name)) {
 718                if (!valid_remote(ret))
 719                        read_remotes_file(ret);
 720                if (!valid_remote(ret))
 721                        read_branches_file(ret);
 722        }
 723        if (name_given && !valid_remote(ret))
 724                add_url_alias(ret, name);
 725        if (!valid_remote(ret))
 726                return NULL;
 727        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 728        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 729        return ret;
 730}
 731
 732struct remote *remote_get(const char *name)
 733{
 734        read_config();
 735        return remote_get_1(name, NULL);
 736}
 737
 738struct remote *pushremote_get(const char *name)
 739{
 740        read_config();
 741        return remote_get_1(name, pushremote_name);
 742}
 743
 744int remote_is_configured(const char *name)
 745{
 746        struct remotes_hash_key lookup;
 747        struct hashmap_entry lookup_entry;
 748        read_config();
 749
 750        init_remotes_hash();
 751        lookup.str = name;
 752        lookup.len = strlen(name);
 753        hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
 754
 755        return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
 756}
 757
 758int for_each_remote(each_remote_fn fn, void *priv)
 759{
 760        int i, result = 0;
 761        read_config();
 762        for (i = 0; i < remotes_nr && !result; i++) {
 763                struct remote *r = remotes[i];
 764                if (!r)
 765                        continue;
 766                if (!r->fetch)
 767                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 768                                                       r->fetch_refspec);
 769                if (!r->push)
 770                        r->push = parse_push_refspec(r->push_refspec_nr,
 771                                                     r->push_refspec);
 772                result = fn(r, priv);
 773        }
 774        return result;
 775}
 776
 777static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 778{
 779        if (strcmp(ref1->name, ref2->name)) {
 780                if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 781                    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 782                        die(_("Cannot fetch both %s and %s to %s"),
 783                            ref1->name, ref2->name, ref2->peer_ref->name);
 784                } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 785                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 786                        warning(_("%s usually tracks %s, not %s"),
 787                                ref2->peer_ref->name, ref2->name, ref1->name);
 788                } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 789                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 790                        die(_("%s tracks both %s and %s"),
 791                            ref2->peer_ref->name, ref1->name, ref2->name);
 792                } else {
 793                        /*
 794                         * This last possibility doesn't occur because
 795                         * FETCH_HEAD_IGNORE entries always appear at
 796                         * the end of the list.
 797                         */
 798                        die(_("Internal error"));
 799                }
 800        }
 801        free(ref2->peer_ref);
 802        free(ref2);
 803}
 804
 805struct ref *ref_remove_duplicates(struct ref *ref_map)
 806{
 807        struct string_list refs = STRING_LIST_INIT_NODUP;
 808        struct ref *retval = NULL;
 809        struct ref **p = &retval;
 810
 811        while (ref_map) {
 812                struct ref *ref = ref_map;
 813
 814                ref_map = ref_map->next;
 815                ref->next = NULL;
 816
 817                if (!ref->peer_ref) {
 818                        *p = ref;
 819                        p = &ref->next;
 820                } else {
 821                        struct string_list_item *item =
 822                                string_list_insert(&refs, ref->peer_ref->name);
 823
 824                        if (item->util) {
 825                                /* Entry already existed */
 826                                handle_duplicate((struct ref *)item->util, ref);
 827                        } else {
 828                                *p = ref;
 829                                p = &ref->next;
 830                                item->util = ref;
 831                        }
 832                }
 833        }
 834
 835        string_list_clear(&refs, 0);
 836        return retval;
 837}
 838
 839int remote_has_url(struct remote *remote, const char *url)
 840{
 841        int i;
 842        for (i = 0; i < remote->url_nr; i++) {
 843                if (!strcmp(remote->url[i], url))
 844                        return 1;
 845        }
 846        return 0;
 847}
 848
 849static int match_name_with_pattern(const char *key, const char *name,
 850                                   const char *value, char **result)
 851{
 852        const char *kstar = strchr(key, '*');
 853        size_t klen;
 854        size_t ksuffixlen;
 855        size_t namelen;
 856        int ret;
 857        if (!kstar)
 858                die("Key '%s' of pattern had no '*'", key);
 859        klen = kstar - key;
 860        ksuffixlen = strlen(kstar + 1);
 861        namelen = strlen(name);
 862        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 863                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 864        if (ret && value) {
 865                struct strbuf sb = STRBUF_INIT;
 866                const char *vstar = strchr(value, '*');
 867                if (!vstar)
 868                        die("Value '%s' of pattern has no '*'", value);
 869                strbuf_add(&sb, value, vstar - value);
 870                strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 871                strbuf_addstr(&sb, vstar + 1);
 872                *result = strbuf_detach(&sb, NULL);
 873        }
 874        return ret;
 875}
 876
 877static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 878{
 879        int i;
 880        int find_src = !query->src;
 881
 882        if (find_src && !query->dst)
 883                error("query_refspecs_multiple: need either src or dst");
 884
 885        for (i = 0; i < ref_count; i++) {
 886                struct refspec *refspec = &refs[i];
 887                const char *key = find_src ? refspec->dst : refspec->src;
 888                const char *value = find_src ? refspec->src : refspec->dst;
 889                const char *needle = find_src ? query->dst : query->src;
 890                char **result = find_src ? &query->src : &query->dst;
 891
 892                if (!refspec->dst)
 893                        continue;
 894                if (refspec->pattern) {
 895                        if (match_name_with_pattern(key, needle, value, result))
 896                                string_list_append_nodup(results, *result);
 897                } else if (!strcmp(needle, key)) {
 898                        string_list_append(results, value);
 899                }
 900        }
 901}
 902
 903int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 904{
 905        int i;
 906        int find_src = !query->src;
 907        const char *needle = find_src ? query->dst : query->src;
 908        char **result = find_src ? &query->src : &query->dst;
 909
 910        if (find_src && !query->dst)
 911                return error("query_refspecs: need either src or dst");
 912
 913        for (i = 0; i < ref_count; i++) {
 914                struct refspec *refspec = &refs[i];
 915                const char *key = find_src ? refspec->dst : refspec->src;
 916                const char *value = find_src ? refspec->src : refspec->dst;
 917
 918                if (!refspec->dst)
 919                        continue;
 920                if (refspec->pattern) {
 921                        if (match_name_with_pattern(key, needle, value, result)) {
 922                                query->force = refspec->force;
 923                                return 0;
 924                        }
 925                } else if (!strcmp(needle, key)) {
 926                        *result = xstrdup(value);
 927                        query->force = refspec->force;
 928                        return 0;
 929                }
 930        }
 931        return -1;
 932}
 933
 934char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 935                     const char *name)
 936{
 937        struct refspec query;
 938
 939        memset(&query, 0, sizeof(struct refspec));
 940        query.src = (char *)name;
 941
 942        if (query_refspecs(refspecs, nr_refspec, &query))
 943                return NULL;
 944
 945        return query.dst;
 946}
 947
 948int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 949{
 950        return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 951}
 952
 953static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 954                const char *name)
 955{
 956        size_t len = strlen(name);
 957        struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 958        memcpy(ref->name, prefix, prefixlen);
 959        memcpy(ref->name + prefixlen, name, len);
 960        return ref;
 961}
 962
 963struct ref *alloc_ref(const char *name)
 964{
 965        return alloc_ref_with_prefix("", 0, name);
 966}
 967
 968struct ref *copy_ref(const struct ref *ref)
 969{
 970        struct ref *cpy;
 971        size_t len;
 972        if (!ref)
 973                return NULL;
 974        len = strlen(ref->name);
 975        cpy = xmalloc(sizeof(struct ref) + len + 1);
 976        memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 977        cpy->next = NULL;
 978        cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 979        cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 980        cpy->peer_ref = copy_ref(ref->peer_ref);
 981        return cpy;
 982}
 983
 984struct ref *copy_ref_list(const struct ref *ref)
 985{
 986        struct ref *ret = NULL;
 987        struct ref **tail = &ret;
 988        while (ref) {
 989                *tail = copy_ref(ref);
 990                ref = ref->next;
 991                tail = &((*tail)->next);
 992        }
 993        return ret;
 994}
 995
 996static void free_ref(struct ref *ref)
 997{
 998        if (!ref)
 999                return;
1000        free_ref(ref->peer_ref);
1001        free(ref->remote_status);
1002        free(ref->symref);
1003        free(ref);
1004}
1005
1006void free_refs(struct ref *ref)
1007{
1008        struct ref *next;
1009        while (ref) {
1010                next = ref->next;
1011                free_ref(ref);
1012                ref = next;
1013        }
1014}
1015
1016int ref_compare_name(const void *va, const void *vb)
1017{
1018        const struct ref *a = va, *b = vb;
1019        return strcmp(a->name, b->name);
1020}
1021
1022static void *ref_list_get_next(const void *a)
1023{
1024        return ((const struct ref *)a)->next;
1025}
1026
1027static void ref_list_set_next(void *a, void *next)
1028{
1029        ((struct ref *)a)->next = next;
1030}
1031
1032void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1033{
1034        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1035}
1036
1037int count_refspec_match(const char *pattern,
1038                        struct ref *refs,
1039                        struct ref **matched_ref)
1040{
1041        int patlen = strlen(pattern);
1042        struct ref *matched_weak = NULL;
1043        struct ref *matched = NULL;
1044        int weak_match = 0;
1045        int match = 0;
1046
1047        for (weak_match = match = 0; refs; refs = refs->next) {
1048                char *name = refs->name;
1049                int namelen = strlen(name);
1050
1051                if (!refname_match(pattern, name))
1052                        continue;
1053
1054                /* A match is "weak" if it is with refs outside
1055                 * heads or tags, and did not specify the pattern
1056                 * in full (e.g. "refs/remotes/origin/master") or at
1057                 * least from the toplevel (e.g. "remotes/origin/master");
1058                 * otherwise "git push $URL master" would result in
1059                 * ambiguity between remotes/origin/master and heads/master
1060                 * at the remote site.
1061                 */
1062                if (namelen != patlen &&
1063                    patlen != namelen - 5 &&
1064                    !starts_with(name, "refs/heads/") &&
1065                    !starts_with(name, "refs/tags/")) {
1066                        /* We want to catch the case where only weak
1067                         * matches are found and there are multiple
1068                         * matches, and where more than one strong
1069                         * matches are found, as ambiguous.  One
1070                         * strong match with zero or more weak matches
1071                         * are acceptable as a unique match.
1072                         */
1073                        matched_weak = refs;
1074                        weak_match++;
1075                }
1076                else {
1077                        matched = refs;
1078                        match++;
1079                }
1080        }
1081        if (!matched) {
1082                if (matched_ref)
1083                        *matched_ref = matched_weak;
1084                return weak_match;
1085        }
1086        else {
1087                if (matched_ref)
1088                        *matched_ref = matched;
1089                return match;
1090        }
1091}
1092
1093static void tail_link_ref(struct ref *ref, struct ref ***tail)
1094{
1095        **tail = ref;
1096        while (ref->next)
1097                ref = ref->next;
1098        *tail = &ref->next;
1099}
1100
1101static struct ref *alloc_delete_ref(void)
1102{
1103        struct ref *ref = alloc_ref("(delete)");
1104        hashclr(ref->new_sha1);
1105        return ref;
1106}
1107
1108static int try_explicit_object_name(const char *name,
1109                                    struct ref **match)
1110{
1111        unsigned char sha1[20];
1112
1113        if (!*name) {
1114                if (match)
1115                        *match = alloc_delete_ref();
1116                return 0;
1117        }
1118
1119        if (get_sha1(name, sha1))
1120                return -1;
1121
1122        if (match) {
1123                *match = alloc_ref(name);
1124                hashcpy((*match)->new_sha1, sha1);
1125        }
1126        return 0;
1127}
1128
1129static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1130{
1131        struct ref *ret = alloc_ref(name);
1132        tail_link_ref(ret, tail);
1133        return ret;
1134}
1135
1136static char *guess_ref(const char *name, struct ref *peer)
1137{
1138        struct strbuf buf = STRBUF_INIT;
1139        unsigned char sha1[20];
1140
1141        const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1142                                           sha1, NULL);
1143        if (!r)
1144                return NULL;
1145
1146        if (starts_with(r, "refs/heads/"))
1147                strbuf_addstr(&buf, "refs/heads/");
1148        else if (starts_with(r, "refs/tags/"))
1149                strbuf_addstr(&buf, "refs/tags/");
1150        else
1151                return NULL;
1152
1153        strbuf_addstr(&buf, name);
1154        return strbuf_detach(&buf, NULL);
1155}
1156
1157static int match_explicit_lhs(struct ref *src,
1158                              struct refspec *rs,
1159                              struct ref **match,
1160                              int *allocated_match)
1161{
1162        switch (count_refspec_match(rs->src, src, match)) {
1163        case 1:
1164                if (allocated_match)
1165                        *allocated_match = 0;
1166                return 0;
1167        case 0:
1168                /* The source could be in the get_sha1() format
1169                 * not a reference name.  :refs/other is a
1170                 * way to delete 'other' ref at the remote end.
1171                 */
1172                if (try_explicit_object_name(rs->src, match) < 0)
1173                        return error("src refspec %s does not match any.", rs->src);
1174                if (allocated_match)
1175                        *allocated_match = 1;
1176                return 0;
1177        default:
1178                return error("src refspec %s matches more than one.", rs->src);
1179        }
1180}
1181
1182static int match_explicit(struct ref *src, struct ref *dst,
1183                          struct ref ***dst_tail,
1184                          struct refspec *rs)
1185{
1186        struct ref *matched_src, *matched_dst;
1187        int allocated_src;
1188
1189        const char *dst_value = rs->dst;
1190        char *dst_guess;
1191
1192        if (rs->pattern || rs->matching)
1193                return 0;
1194
1195        matched_src = matched_dst = NULL;
1196        if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1197                return -1;
1198
1199        if (!dst_value) {
1200                unsigned char sha1[20];
1201                int flag;
1202
1203                dst_value = resolve_ref_unsafe(matched_src->name,
1204                                               RESOLVE_REF_READING,
1205                                               sha1, &flag);
1206                if (!dst_value ||
1207                    ((flag & REF_ISSYMREF) &&
1208                     !starts_with(dst_value, "refs/heads/")))
1209                        die("%s cannot be resolved to branch.",
1210                            matched_src->name);
1211        }
1212
1213        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1214        case 1:
1215                break;
1216        case 0:
1217                if (starts_with(dst_value, "refs/"))
1218                        matched_dst = make_linked_ref(dst_value, dst_tail);
1219                else if (is_null_sha1(matched_src->new_sha1))
1220                        error("unable to delete '%s': remote ref does not exist",
1221                              dst_value);
1222                else if ((dst_guess = guess_ref(dst_value, matched_src)))
1223                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1224                else
1225                        error("unable to push to unqualified destination: %s\n"
1226                              "The destination refspec neither matches an "
1227                              "existing ref on the remote nor\n"
1228                              "begins with refs/, and we are unable to "
1229                              "guess a prefix based on the source ref.",
1230                              dst_value);
1231                break;
1232        default:
1233                matched_dst = NULL;
1234                error("dst refspec %s matches more than one.",
1235                      dst_value);
1236                break;
1237        }
1238        if (!matched_dst)
1239                return -1;
1240        if (matched_dst->peer_ref)
1241                return error("dst ref %s receives from more than one src.",
1242                      matched_dst->name);
1243        else {
1244                matched_dst->peer_ref = allocated_src ?
1245                                        matched_src :
1246                                        copy_ref(matched_src);
1247                matched_dst->force = rs->force;
1248        }
1249        return 0;
1250}
1251
1252static int match_explicit_refs(struct ref *src, struct ref *dst,
1253                               struct ref ***dst_tail, struct refspec *rs,
1254                               int rs_nr)
1255{
1256        int i, errs;
1257        for (i = errs = 0; i < rs_nr; i++)
1258                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1259        return errs;
1260}
1261
1262static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1263                int send_mirror, int direction, const struct refspec **ret_pat)
1264{
1265        const struct refspec *pat;
1266        char *name;
1267        int i;
1268        int matching_refs = -1;
1269        for (i = 0; i < rs_nr; i++) {
1270                if (rs[i].matching &&
1271                    (matching_refs == -1 || rs[i].force)) {
1272                        matching_refs = i;
1273                        continue;
1274                }
1275
1276                if (rs[i].pattern) {
1277                        const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1278                        int match;
1279                        if (direction == FROM_SRC)
1280                                match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1281                        else
1282                                match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1283                        if (match) {
1284                                matching_refs = i;
1285                                break;
1286                        }
1287                }
1288        }
1289        if (matching_refs == -1)
1290                return NULL;
1291
1292        pat = rs + matching_refs;
1293        if (pat->matching) {
1294                /*
1295                 * "matching refs"; traditionally we pushed everything
1296                 * including refs outside refs/heads/ hierarchy, but
1297                 * that does not make much sense these days.
1298                 */
1299                if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1300                        return NULL;
1301                name = xstrdup(ref->name);
1302        }
1303        if (ret_pat)
1304                *ret_pat = pat;
1305        return name;
1306}
1307
1308static struct ref **tail_ref(struct ref **head)
1309{
1310        struct ref **tail = head;
1311        while (*tail)
1312                tail = &((*tail)->next);
1313        return tail;
1314}
1315
1316struct tips {
1317        struct commit **tip;
1318        int nr, alloc;
1319};
1320
1321static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1322{
1323        struct commit *commit;
1324
1325        if (is_null_sha1(sha1))
1326                return;
1327        commit = lookup_commit_reference_gently(sha1, 1);
1328        if (!commit || (commit->object.flags & TMP_MARK))
1329                return;
1330        commit->object.flags |= TMP_MARK;
1331        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1332        tips->tip[tips->nr++] = commit;
1333}
1334
1335static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1336{
1337        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1338        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1339        struct string_list_item *item;
1340        struct ref *ref;
1341        struct tips sent_tips;
1342
1343        /*
1344         * Collect everything we know they would have at the end of
1345         * this push, and collect all tags they have.
1346         */
1347        memset(&sent_tips, 0, sizeof(sent_tips));
1348        for (ref = *dst; ref; ref = ref->next) {
1349                if (ref->peer_ref &&
1350                    !is_null_sha1(ref->peer_ref->new_sha1))
1351                        add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1352                else
1353                        add_to_tips(&sent_tips, ref->old_sha1);
1354                if (starts_with(ref->name, "refs/tags/"))
1355                        string_list_append(&dst_tag, ref->name);
1356        }
1357        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1358
1359        sort_string_list(&dst_tag);
1360
1361        /* Collect tags they do not have. */
1362        for (ref = src; ref; ref = ref->next) {
1363                if (!starts_with(ref->name, "refs/tags/"))
1364                        continue; /* not a tag */
1365                if (string_list_has_string(&dst_tag, ref->name))
1366                        continue; /* they already have it */
1367                if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1368                        continue; /* be conservative */
1369                item = string_list_append(&src_tag, ref->name);
1370                item->util = ref;
1371        }
1372        string_list_clear(&dst_tag, 0);
1373
1374        /*
1375         * At this point, src_tag lists tags that are missing from
1376         * dst, and sent_tips lists the tips we are pushing or those
1377         * that we know they already have. An element in the src_tag
1378         * that is an ancestor of any of the sent_tips needs to be
1379         * sent to the other side.
1380         */
1381        if (sent_tips.nr) {
1382                for_each_string_list_item(item, &src_tag) {
1383                        struct ref *ref = item->util;
1384                        struct ref *dst_ref;
1385                        struct commit *commit;
1386
1387                        if (is_null_sha1(ref->new_sha1))
1388                                continue;
1389                        commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1390                        if (!commit)
1391                                /* not pushing a commit, which is not an error */
1392                                continue;
1393
1394                        /*
1395                         * Is this tag, which they do not have, reachable from
1396                         * any of the commits we are sending?
1397                         */
1398                        if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1399                                continue;
1400
1401                        /* Add it in */
1402                        dst_ref = make_linked_ref(ref->name, dst_tail);
1403                        hashcpy(dst_ref->new_sha1, ref->new_sha1);
1404                        dst_ref->peer_ref = copy_ref(ref);
1405                }
1406        }
1407        string_list_clear(&src_tag, 0);
1408        free(sent_tips.tip);
1409}
1410
1411struct ref *find_ref_by_name(const struct ref *list, const char *name)
1412{
1413        for ( ; list; list = list->next)
1414                if (!strcmp(list->name, name))
1415                        return (struct ref *)list;
1416        return NULL;
1417}
1418
1419static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1420{
1421        for ( ; ref; ref = ref->next)
1422                string_list_append_nodup(ref_index, ref->name)->util = ref;
1423
1424        sort_string_list(ref_index);
1425}
1426
1427/*
1428 * Given only the set of local refs, sanity-check the set of push
1429 * refspecs. We can't catch all errors that match_push_refs would,
1430 * but we can catch some errors early before even talking to the
1431 * remote side.
1432 */
1433int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1434{
1435        struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1436        int ret = 0;
1437        int i;
1438
1439        for (i = 0; i < nr_refspec; i++) {
1440                struct refspec *rs = refspec + i;
1441
1442                if (rs->pattern || rs->matching)
1443                        continue;
1444
1445                ret |= match_explicit_lhs(src, rs, NULL, NULL);
1446        }
1447
1448        free_refspec(nr_refspec, refspec);
1449        return ret;
1450}
1451
1452/*
1453 * Given the set of refs the local repository has, the set of refs the
1454 * remote repository has, and the refspec used for push, determine
1455 * what remote refs we will update and with what value by setting
1456 * peer_ref (which object is being pushed) and force (if the push is
1457 * forced) in elements of "dst". The function may add new elements to
1458 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1459 */
1460int match_push_refs(struct ref *src, struct ref **dst,
1461                    int nr_refspec, const char **refspec, int flags)
1462{
1463        struct refspec *rs;
1464        int send_all = flags & MATCH_REFS_ALL;
1465        int send_mirror = flags & MATCH_REFS_MIRROR;
1466        int send_prune = flags & MATCH_REFS_PRUNE;
1467        int errs;
1468        static const char *default_refspec[] = { ":", NULL };
1469        struct ref *ref, **dst_tail = tail_ref(dst);
1470        struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1471
1472        if (!nr_refspec) {
1473                nr_refspec = 1;
1474                refspec = default_refspec;
1475        }
1476        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1477        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1478
1479        /* pick the remainder */
1480        for (ref = src; ref; ref = ref->next) {
1481                struct string_list_item *dst_item;
1482                struct ref *dst_peer;
1483                const struct refspec *pat = NULL;
1484                char *dst_name;
1485
1486                dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1487                if (!dst_name)
1488                        continue;
1489
1490                if (!dst_ref_index.nr)
1491                        prepare_ref_index(&dst_ref_index, *dst);
1492
1493                dst_item = string_list_lookup(&dst_ref_index, dst_name);
1494                dst_peer = dst_item ? dst_item->util : NULL;
1495                if (dst_peer) {
1496                        if (dst_peer->peer_ref)
1497                                /* We're already sending something to this ref. */
1498                                goto free_name;
1499                } else {
1500                        if (pat->matching && !(send_all || send_mirror))
1501                                /*
1502                                 * Remote doesn't have it, and we have no
1503                                 * explicit pattern, and we don't have
1504                                 * --all or --mirror.
1505                                 */
1506                                goto free_name;
1507
1508                        /* Create a new one and link it */
1509                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1510                        hashcpy(dst_peer->new_sha1, ref->new_sha1);
1511                        string_list_insert(&dst_ref_index,
1512                                dst_peer->name)->util = dst_peer;
1513                }
1514                dst_peer->peer_ref = copy_ref(ref);
1515                dst_peer->force = pat->force;
1516        free_name:
1517                free(dst_name);
1518        }
1519
1520        string_list_clear(&dst_ref_index, 0);
1521
1522        if (flags & MATCH_REFS_FOLLOW_TAGS)
1523                add_missing_tags(src, dst, &dst_tail);
1524
1525        if (send_prune) {
1526                struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1527                /* check for missing refs on the remote */
1528                for (ref = *dst; ref; ref = ref->next) {
1529                        char *src_name;
1530
1531                        if (ref->peer_ref)
1532                                /* We're already sending something to this ref. */
1533                                continue;
1534
1535                        src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1536                        if (src_name) {
1537                                if (!src_ref_index.nr)
1538                                        prepare_ref_index(&src_ref_index, src);
1539                                if (!string_list_has_string(&src_ref_index,
1540                                            src_name))
1541                                        ref->peer_ref = alloc_delete_ref();
1542                                free(src_name);
1543                        }
1544                }
1545                string_list_clear(&src_ref_index, 0);
1546        }
1547        if (errs)
1548                return -1;
1549        return 0;
1550}
1551
1552void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1553                             int force_update)
1554{
1555        struct ref *ref;
1556
1557        for (ref = remote_refs; ref; ref = ref->next) {
1558                int force_ref_update = ref->force || force_update;
1559                int reject_reason = 0;
1560
1561                if (ref->peer_ref)
1562                        hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1563                else if (!send_mirror)
1564                        continue;
1565
1566                ref->deletion = is_null_sha1(ref->new_sha1);
1567                if (!ref->deletion &&
1568                        !hashcmp(ref->old_sha1, ref->new_sha1)) {
1569                        ref->status = REF_STATUS_UPTODATE;
1570                        continue;
1571                }
1572
1573                /*
1574                 * Bypass the usual "must fast-forward" check but
1575                 * replace it with a weaker "the old value must be
1576                 * this value we observed".  If the remote ref has
1577                 * moved and is now different from what we expect,
1578                 * reject any push.
1579                 *
1580                 * It also is an error if the user told us to check
1581                 * with the remote-tracking branch to find the value
1582                 * to expect, but we did not have such a tracking
1583                 * branch.
1584                 */
1585                if (ref->expect_old_sha1) {
1586                        if (ref->expect_old_no_trackback ||
1587                            hashcmp(ref->old_sha1, ref->old_sha1_expect))
1588                                reject_reason = REF_STATUS_REJECT_STALE;
1589                }
1590
1591                /*
1592                 * The usual "must fast-forward" rules.
1593                 *
1594                 * Decide whether an individual refspec A:B can be
1595                 * pushed.  The push will succeed if any of the
1596                 * following are true:
1597                 *
1598                 * (1) the remote reference B does not exist
1599                 *
1600                 * (2) the remote reference B is being removed (i.e.,
1601                 *     pushing :B where no source is specified)
1602                 *
1603                 * (3) the destination is not under refs/tags/, and
1604                 *     if the old and new value is a commit, the new
1605                 *     is a descendant of the old.
1606                 *
1607                 * (4) it is forced using the +A:B notation, or by
1608                 *     passing the --force argument
1609                 */
1610
1611                else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1612                        if (starts_with(ref->name, "refs/tags/"))
1613                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1614                        else if (!has_sha1_file(ref->old_sha1))
1615                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1616                        else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1617                                 !lookup_commit_reference_gently(ref->new_sha1, 1))
1618                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1619                        else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1620                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1621                }
1622
1623                /*
1624                 * "--force" will defeat any rejection implemented
1625                 * by the rules above.
1626                 */
1627                if (!force_ref_update)
1628                        ref->status = reject_reason;
1629                else if (reject_reason)
1630                        ref->forced_update = 1;
1631        }
1632}
1633
1634struct branch *branch_get(const char *name)
1635{
1636        struct branch *ret;
1637
1638        read_config();
1639        if (!name || !*name || !strcmp(name, "HEAD"))
1640                ret = current_branch;
1641        else
1642                ret = make_branch(name, 0);
1643        if (ret && ret->remote_name) {
1644                ret->remote = remote_get(ret->remote_name);
1645                if (ret->merge_nr) {
1646                        int i;
1647                        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1648                        for (i = 0; i < ret->merge_nr; i++) {
1649                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1650                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1651                                if (remote_find_tracking(ret->remote, ret->merge[i])
1652                                    && !strcmp(ret->remote_name, "."))
1653                                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1654                        }
1655                }
1656        }
1657        return ret;
1658}
1659
1660int branch_has_merge_config(struct branch *branch)
1661{
1662        return branch && !!branch->merge;
1663}
1664
1665int branch_merge_matches(struct branch *branch,
1666                                 int i,
1667                                 const char *refname)
1668{
1669        if (!branch || i < 0 || i >= branch->merge_nr)
1670                return 0;
1671        return refname_match(branch->merge[i]->src, refname);
1672}
1673
1674static int ignore_symref_update(const char *refname)
1675{
1676        unsigned char sha1[20];
1677        int flag;
1678
1679        if (!resolve_ref_unsafe(refname, 0, sha1, &flag))
1680                return 0; /* non-existing refs are OK */
1681        return (flag & REF_ISSYMREF);
1682}
1683
1684/*
1685 * Create and return a list of (struct ref) consisting of copies of
1686 * each remote_ref that matches refspec.  refspec must be a pattern.
1687 * Fill in the copies' peer_ref to describe the local tracking refs to
1688 * which they map.  Omit any references that would map to an existing
1689 * local symbolic ref.
1690 */
1691static struct ref *get_expanded_map(const struct ref *remote_refs,
1692                                    const struct refspec *refspec)
1693{
1694        const struct ref *ref;
1695        struct ref *ret = NULL;
1696        struct ref **tail = &ret;
1697
1698        for (ref = remote_refs; ref; ref = ref->next) {
1699                char *expn_name = NULL;
1700
1701                if (strchr(ref->name, '^'))
1702                        continue; /* a dereference item */
1703                if (match_name_with_pattern(refspec->src, ref->name,
1704                                            refspec->dst, &expn_name) &&
1705                    !ignore_symref_update(expn_name)) {
1706                        struct ref *cpy = copy_ref(ref);
1707
1708                        cpy->peer_ref = alloc_ref(expn_name);
1709                        if (refspec->force)
1710                                cpy->peer_ref->force = 1;
1711                        *tail = cpy;
1712                        tail = &cpy->next;
1713                }
1714                free(expn_name);
1715        }
1716
1717        return ret;
1718}
1719
1720static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1721{
1722        const struct ref *ref;
1723        for (ref = refs; ref; ref = ref->next) {
1724                if (refname_match(name, ref->name))
1725                        return ref;
1726        }
1727        return NULL;
1728}
1729
1730struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1731{
1732        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1733
1734        if (!ref)
1735                return NULL;
1736
1737        return copy_ref(ref);
1738}
1739
1740static struct ref *get_local_ref(const char *name)
1741{
1742        if (!name || name[0] == '\0')
1743                return NULL;
1744
1745        if (starts_with(name, "refs/"))
1746                return alloc_ref(name);
1747
1748        if (starts_with(name, "heads/") ||
1749            starts_with(name, "tags/") ||
1750            starts_with(name, "remotes/"))
1751                return alloc_ref_with_prefix("refs/", 5, name);
1752
1753        return alloc_ref_with_prefix("refs/heads/", 11, name);
1754}
1755
1756int get_fetch_map(const struct ref *remote_refs,
1757                  const struct refspec *refspec,
1758                  struct ref ***tail,
1759                  int missing_ok)
1760{
1761        struct ref *ref_map, **rmp;
1762
1763        if (refspec->pattern) {
1764                ref_map = get_expanded_map(remote_refs, refspec);
1765        } else {
1766                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1767
1768                if (refspec->exact_sha1) {
1769                        ref_map = alloc_ref(name);
1770                        get_sha1_hex(name, ref_map->old_sha1);
1771                } else {
1772                        ref_map = get_remote_ref(remote_refs, name);
1773                }
1774                if (!missing_ok && !ref_map)
1775                        die("Couldn't find remote ref %s", name);
1776                if (ref_map) {
1777                        ref_map->peer_ref = get_local_ref(refspec->dst);
1778                        if (ref_map->peer_ref && refspec->force)
1779                                ref_map->peer_ref->force = 1;
1780                }
1781        }
1782
1783        for (rmp = &ref_map; *rmp; ) {
1784                if ((*rmp)->peer_ref) {
1785                        if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1786                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1787                                struct ref *ignore = *rmp;
1788                                error("* Ignoring funny ref '%s' locally",
1789                                      (*rmp)->peer_ref->name);
1790                                *rmp = (*rmp)->next;
1791                                free(ignore->peer_ref);
1792                                free(ignore);
1793                                continue;
1794                        }
1795                }
1796                rmp = &((*rmp)->next);
1797        }
1798
1799        if (ref_map)
1800                tail_link_ref(ref_map, tail);
1801
1802        return 0;
1803}
1804
1805int resolve_remote_symref(struct ref *ref, struct ref *list)
1806{
1807        if (!ref->symref)
1808                return 0;
1809        for (; list; list = list->next)
1810                if (!strcmp(ref->symref, list->name)) {
1811                        hashcpy(ref->old_sha1, list->old_sha1);
1812                        return 0;
1813                }
1814        return 1;
1815}
1816
1817static void unmark_and_free(struct commit_list *list, unsigned int mark)
1818{
1819        while (list) {
1820                struct commit_list *temp = list;
1821                temp->item->object.flags &= ~mark;
1822                list = temp->next;
1823                free(temp);
1824        }
1825}
1826
1827int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1828{
1829        struct object *o;
1830        struct commit *old, *new;
1831        struct commit_list *list, *used;
1832        int found = 0;
1833
1834        /*
1835         * Both new and old must be commit-ish and new is descendant of
1836         * old.  Otherwise we require --force.
1837         */
1838        o = deref_tag(parse_object(old_sha1), NULL, 0);
1839        if (!o || o->type != OBJ_COMMIT)
1840                return 0;
1841        old = (struct commit *) o;
1842
1843        o = deref_tag(parse_object(new_sha1), NULL, 0);
1844        if (!o || o->type != OBJ_COMMIT)
1845                return 0;
1846        new = (struct commit *) o;
1847
1848        if (parse_commit(new) < 0)
1849                return 0;
1850
1851        used = list = NULL;
1852        commit_list_insert(new, &list);
1853        while (list) {
1854                new = pop_most_recent_commit(&list, TMP_MARK);
1855                commit_list_insert(new, &used);
1856                if (new == old) {
1857                        found = 1;
1858                        break;
1859                }
1860        }
1861        unmark_and_free(list, TMP_MARK);
1862        unmark_and_free(used, TMP_MARK);
1863        return found;
1864}
1865
1866/*
1867 * Compare a branch with its upstream, and save their differences (number
1868 * of commits) in *num_ours and *num_theirs.
1869 *
1870 * Return 0 if branch has no upstream (no base), -1 if upstream is missing
1871 * (with "gone" base), otherwise 1 (with base).
1872 */
1873int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1874{
1875        unsigned char sha1[20];
1876        struct commit *ours, *theirs;
1877        char symmetric[84];
1878        struct rev_info revs;
1879        const char *rev_argv[10], *base;
1880        int rev_argc;
1881
1882        /* Cannot stat unless we are marked to build on top of somebody else. */
1883        if (!branch ||
1884            !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1885                return 0;
1886
1887        /* Cannot stat if what we used to build on no longer exists */
1888        base = branch->merge[0]->dst;
1889        if (read_ref(base, sha1))
1890                return -1;
1891        theirs = lookup_commit_reference(sha1);
1892        if (!theirs)
1893                return -1;
1894
1895        if (read_ref(branch->refname, sha1))
1896                return -1;
1897        ours = lookup_commit_reference(sha1);
1898        if (!ours)
1899                return -1;
1900
1901        /* are we the same? */
1902        if (theirs == ours) {
1903                *num_theirs = *num_ours = 0;
1904                return 1;
1905        }
1906
1907        /* Run "rev-list --left-right ours...theirs" internally... */
1908        rev_argc = 0;
1909        rev_argv[rev_argc++] = NULL;
1910        rev_argv[rev_argc++] = "--left-right";
1911        rev_argv[rev_argc++] = symmetric;
1912        rev_argv[rev_argc++] = "--";
1913        rev_argv[rev_argc] = NULL;
1914
1915        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1916        strcpy(symmetric + 40, "...");
1917        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1918
1919        init_revisions(&revs, NULL);
1920        setup_revisions(rev_argc, rev_argv, &revs, NULL);
1921        if (prepare_revision_walk(&revs))
1922                die("revision walk setup failed");
1923
1924        /* ... and count the commits on each side. */
1925        *num_ours = 0;
1926        *num_theirs = 0;
1927        while (1) {
1928                struct commit *c = get_revision(&revs);
1929                if (!c)
1930                        break;
1931                if (c->object.flags & SYMMETRIC_LEFT)
1932                        (*num_ours)++;
1933                else
1934                        (*num_theirs)++;
1935        }
1936
1937        /* clear object flags smudged by the above traversal */
1938        clear_commit_marks(ours, ALL_REV_FLAGS);
1939        clear_commit_marks(theirs, ALL_REV_FLAGS);
1940        return 1;
1941}
1942
1943/*
1944 * Return true when there is anything to report, otherwise false.
1945 */
1946int format_tracking_info(struct branch *branch, struct strbuf *sb)
1947{
1948        int ours, theirs;
1949        char *base;
1950        int upstream_is_gone = 0;
1951
1952        switch (stat_tracking_info(branch, &ours, &theirs)) {
1953        case 0:
1954                /* no base */
1955                return 0;
1956        case -1:
1957                /* with "gone" base */
1958                upstream_is_gone = 1;
1959                break;
1960        default:
1961                /* with base */
1962                break;
1963        }
1964
1965        base = shorten_unambiguous_ref(branch->merge[0]->dst, 0);
1966        if (upstream_is_gone) {
1967                strbuf_addf(sb,
1968                        _("Your branch is based on '%s', but the upstream is gone.\n"),
1969                        base);
1970                if (advice_status_hints)
1971                        strbuf_addf(sb,
1972                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1973        } else if (!ours && !theirs) {
1974                strbuf_addf(sb,
1975                        _("Your branch is up-to-date with '%s'.\n"),
1976                        base);
1977        } else if (!theirs) {
1978                strbuf_addf(sb,
1979                        Q_("Your branch is ahead of '%s' by %d commit.\n",
1980                           "Your branch is ahead of '%s' by %d commits.\n",
1981                           ours),
1982                        base, ours);
1983                if (advice_status_hints)
1984                        strbuf_addf(sb,
1985                                _("  (use \"git push\" to publish your local commits)\n"));
1986        } else if (!ours) {
1987                strbuf_addf(sb,
1988                        Q_("Your branch is behind '%s' by %d commit, "
1989                               "and can be fast-forwarded.\n",
1990                           "Your branch is behind '%s' by %d commits, "
1991                               "and can be fast-forwarded.\n",
1992                           theirs),
1993                        base, theirs);
1994                if (advice_status_hints)
1995                        strbuf_addf(sb,
1996                                _("  (use \"git pull\" to update your local branch)\n"));
1997        } else {
1998                strbuf_addf(sb,
1999                        Q_("Your branch and '%s' have diverged,\n"
2000                               "and have %d and %d different commit each, "
2001                               "respectively.\n",
2002                           "Your branch and '%s' have diverged,\n"
2003                               "and have %d and %d different commits each, "
2004                               "respectively.\n",
2005                           theirs),
2006                        base, ours, theirs);
2007                if (advice_status_hints)
2008                        strbuf_addf(sb,
2009                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2010        }
2011        free(base);
2012        return 1;
2013}
2014
2015static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
2016{
2017        struct ref ***local_tail = cb_data;
2018        struct ref *ref;
2019        int len;
2020
2021        /* we already know it starts with refs/ to get here */
2022        if (check_refname_format(refname + 5, 0))
2023                return 0;
2024
2025        len = strlen(refname) + 1;
2026        ref = xcalloc(1, sizeof(*ref) + len);
2027        hashcpy(ref->new_sha1, sha1);
2028        memcpy(ref->name, refname, len);
2029        **local_tail = ref;
2030        *local_tail = &ref->next;
2031        return 0;
2032}
2033
2034struct ref *get_local_heads(void)
2035{
2036        struct ref *local_refs = NULL, **local_tail = &local_refs;
2037        for_each_ref(one_local_ref, &local_tail);
2038        return local_refs;
2039}
2040
2041struct ref *guess_remote_head(const struct ref *head,
2042                              const struct ref *refs,
2043                              int all)
2044{
2045        const struct ref *r;
2046        struct ref *list = NULL;
2047        struct ref **tail = &list;
2048
2049        if (!head)
2050                return NULL;
2051
2052        /*
2053         * Some transports support directly peeking at
2054         * where HEAD points; if that is the case, then
2055         * we don't have to guess.
2056         */
2057        if (head->symref)
2058                return copy_ref(find_ref_by_name(refs, head->symref));
2059
2060        /* If refs/heads/master could be right, it is. */
2061        if (!all) {
2062                r = find_ref_by_name(refs, "refs/heads/master");
2063                if (r && !hashcmp(r->old_sha1, head->old_sha1))
2064                        return copy_ref(r);
2065        }
2066
2067        /* Look for another ref that points there */
2068        for (r = refs; r; r = r->next) {
2069                if (r != head &&
2070                    starts_with(r->name, "refs/heads/") &&
2071                    !hashcmp(r->old_sha1, head->old_sha1)) {
2072                        *tail = copy_ref(r);
2073                        tail = &((*tail)->next);
2074                        if (!all)
2075                                break;
2076                }
2077        }
2078
2079        return list;
2080}
2081
2082struct stale_heads_info {
2083        struct string_list *ref_names;
2084        struct ref **stale_refs_tail;
2085        struct refspec *refs;
2086        int ref_count;
2087};
2088
2089static int get_stale_heads_cb(const char *refname,
2090        const unsigned char *sha1, int flags, void *cb_data)
2091{
2092        struct stale_heads_info *info = cb_data;
2093        struct string_list matches = STRING_LIST_INIT_DUP;
2094        struct refspec query;
2095        int i, stale = 1;
2096        memset(&query, 0, sizeof(struct refspec));
2097        query.dst = (char *)refname;
2098
2099        query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2100        if (matches.nr == 0)
2101                goto clean_exit; /* No matches */
2102
2103        /*
2104         * If we did find a suitable refspec and it's not a symref and
2105         * it's not in the list of refs that currently exist in that
2106         * remote, we consider it to be stale. In order to deal with
2107         * overlapping refspecs, we need to go over all of the
2108         * matching refs.
2109         */
2110        if (flags & REF_ISSYMREF)
2111                goto clean_exit;
2112
2113        for (i = 0; stale && i < matches.nr; i++)
2114                if (string_list_has_string(info->ref_names, matches.items[i].string))
2115                        stale = 0;
2116
2117        if (stale) {
2118                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2119                hashcpy(ref->new_sha1, sha1);
2120        }
2121
2122clean_exit:
2123        string_list_clear(&matches, 0);
2124        return 0;
2125}
2126
2127struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2128{
2129        struct ref *ref, *stale_refs = NULL;
2130        struct string_list ref_names = STRING_LIST_INIT_NODUP;
2131        struct stale_heads_info info;
2132        info.ref_names = &ref_names;
2133        info.stale_refs_tail = &stale_refs;
2134        info.refs = refs;
2135        info.ref_count = ref_count;
2136        for (ref = fetch_map; ref; ref = ref->next)
2137                string_list_append(&ref_names, ref->name);
2138        sort_string_list(&ref_names);
2139        for_each_ref(get_stale_heads_cb, &info);
2140        string_list_clear(&ref_names, 0);
2141        return stale_refs;
2142}
2143
2144/*
2145 * Compare-and-swap
2146 */
2147void clear_cas_option(struct push_cas_option *cas)
2148{
2149        int i;
2150
2151        for (i = 0; i < cas->nr; i++)
2152                free(cas->entry[i].refname);
2153        free(cas->entry);
2154        memset(cas, 0, sizeof(*cas));
2155}
2156
2157static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2158                                      const char *refname,
2159                                      size_t refnamelen)
2160{
2161        struct push_cas *entry;
2162        ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2163        entry = &cas->entry[cas->nr++];
2164        memset(entry, 0, sizeof(*entry));
2165        entry->refname = xmemdupz(refname, refnamelen);
2166        return entry;
2167}
2168
2169int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2170{
2171        const char *colon;
2172        struct push_cas *entry;
2173
2174        if (unset) {
2175                /* "--no-<option>" */
2176                clear_cas_option(cas);
2177                return 0;
2178        }
2179
2180        if (!arg) {
2181                /* just "--<option>" */
2182                cas->use_tracking_for_rest = 1;
2183                return 0;
2184        }
2185
2186        /* "--<option>=refname" or "--<option>=refname:value" */
2187        colon = strchrnul(arg, ':');
2188        entry = add_cas_entry(cas, arg, colon - arg);
2189        if (!*colon)
2190                entry->use_tracking = 1;
2191        else if (get_sha1(colon + 1, entry->expect))
2192                return error("cannot parse expected object name '%s'", colon + 1);
2193        return 0;
2194}
2195
2196int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2197{
2198        return parse_push_cas_option(opt->value, arg, unset);
2199}
2200
2201int is_empty_cas(const struct push_cas_option *cas)
2202{
2203        return !cas->use_tracking_for_rest && !cas->nr;
2204}
2205
2206/*
2207 * Look at remote.fetch refspec and see if we have a remote
2208 * tracking branch for the refname there.  Fill its current
2209 * value in sha1[].
2210 * If we cannot do so, return negative to signal an error.
2211 */
2212static int remote_tracking(struct remote *remote, const char *refname,
2213                           unsigned char sha1[20])
2214{
2215        char *dst;
2216
2217        dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2218        if (!dst)
2219                return -1; /* no tracking ref for refname at remote */
2220        if (read_ref(dst, sha1))
2221                return -1; /* we know what the tracking ref is but we cannot read it */
2222        return 0;
2223}
2224
2225static void apply_cas(struct push_cas_option *cas,
2226                      struct remote *remote,
2227                      struct ref *ref)
2228{
2229        int i;
2230
2231        /* Find an explicit --<option>=<name>[:<value>] entry */
2232        for (i = 0; i < cas->nr; i++) {
2233                struct push_cas *entry = &cas->entry[i];
2234                if (!refname_match(entry->refname, ref->name))
2235                        continue;
2236                ref->expect_old_sha1 = 1;
2237                if (!entry->use_tracking)
2238                        hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2239                else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2240                        ref->expect_old_no_trackback = 1;
2241                return;
2242        }
2243
2244        /* Are we using "--<option>" to cover all? */
2245        if (!cas->use_tracking_for_rest)
2246                return;
2247
2248        ref->expect_old_sha1 = 1;
2249        if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2250                ref->expect_old_no_trackback = 1;
2251}
2252
2253void apply_push_cas(struct push_cas_option *cas,
2254                    struct remote *remote,
2255                    struct ref *remote_refs)
2256{
2257        struct ref *ref;
2258        for (ref = remote_refs; ref; ref = ref->next)
2259                apply_cas(cas, remote, ref);
2260}