remote.con commit Merge branch 'jc/worktree-add-short-help' into maint (e55521b)
   1#include "cache.h"
   2#include "config.h"
   3#include "remote.h"
   4#include "refs.h"
   5#include "commit.h"
   6#include "diff.h"
   7#include "revision.h"
   8#include "dir.h"
   9#include "tag.h"
  10#include "string-list.h"
  11#include "mergesort.h"
  12#include "argv-array.h"
  13
  14enum map_direction { FROM_SRC, FROM_DST };
  15
  16static struct refspec s_tag_refspec = {
  17        0,
  18        1,
  19        0,
  20        0,
  21        "refs/tags/*",
  22        "refs/tags/*"
  23};
  24
  25const struct refspec *tag_refspec = &s_tag_refspec;
  26
  27struct counted_string {
  28        size_t len;
  29        const char *s;
  30};
  31struct rewrite {
  32        const char *base;
  33        size_t baselen;
  34        struct counted_string *instead_of;
  35        int instead_of_nr;
  36        int instead_of_alloc;
  37};
  38struct rewrites {
  39        struct rewrite **rewrite;
  40        int rewrite_alloc;
  41        int rewrite_nr;
  42};
  43
  44static struct remote **remotes;
  45static int remotes_alloc;
  46static int remotes_nr;
  47static struct hashmap remotes_hash;
  48
  49static struct branch **branches;
  50static int branches_alloc;
  51static int branches_nr;
  52
  53static struct branch *current_branch;
  54static const char *pushremote_name;
  55
  56static struct rewrites rewrites;
  57static struct rewrites rewrites_push;
  58
  59static int valid_remote(const struct remote *remote)
  60{
  61        return (!!remote->url) || (!!remote->foreign_vcs);
  62}
  63
  64static const char *alias_url(const char *url, struct rewrites *r)
  65{
  66        int i, j;
  67        struct counted_string *longest;
  68        int longest_i;
  69
  70        longest = NULL;
  71        longest_i = -1;
  72        for (i = 0; i < r->rewrite_nr; i++) {
  73                if (!r->rewrite[i])
  74                        continue;
  75                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  76                        if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  77                            (!longest ||
  78                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  79                                longest = &(r->rewrite[i]->instead_of[j]);
  80                                longest_i = i;
  81                        }
  82                }
  83        }
  84        if (!longest)
  85                return url;
  86
  87        return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  88}
  89
  90static void add_push_refspec(struct remote *remote, const char *ref)
  91{
  92        ALLOC_GROW(remote->push_refspec,
  93                   remote->push_refspec_nr + 1,
  94                   remote->push_refspec_alloc);
  95        remote->push_refspec[remote->push_refspec_nr++] = ref;
  96}
  97
  98static void add_fetch_refspec(struct remote *remote, const char *ref)
  99{
 100        ALLOC_GROW(remote->fetch_refspec,
 101                   remote->fetch_refspec_nr + 1,
 102                   remote->fetch_refspec_alloc);
 103        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 104}
 105
 106static void add_url(struct remote *remote, const char *url)
 107{
 108        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 109        remote->url[remote->url_nr++] = url;
 110}
 111
 112static void add_pushurl(struct remote *remote, const char *pushurl)
 113{
 114        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 115        remote->pushurl[remote->pushurl_nr++] = pushurl;
 116}
 117
 118static void add_pushurl_alias(struct remote *remote, const char *url)
 119{
 120        const char *pushurl = alias_url(url, &rewrites_push);
 121        if (pushurl != url)
 122                add_pushurl(remote, pushurl);
 123}
 124
 125static void add_url_alias(struct remote *remote, const char *url)
 126{
 127        add_url(remote, alias_url(url, &rewrites));
 128        add_pushurl_alias(remote, url);
 129}
 130
 131struct remotes_hash_key {
 132        const char *str;
 133        int len;
 134};
 135
 136static int remotes_hash_cmp(const void *unused_cmp_data,
 137                            const void *entry,
 138                            const void *entry_or_key,
 139                            const void *keydata)
 140{
 141        const struct remote *a = entry;
 142        const struct remote *b = entry_or_key;
 143        const struct remotes_hash_key *key = keydata;
 144
 145        if (key)
 146                return strncmp(a->name, key->str, key->len) || a->name[key->len];
 147        else
 148                return strcmp(a->name, b->name);
 149}
 150
 151static inline void init_remotes_hash(void)
 152{
 153        if (!remotes_hash.cmpfn)
 154                hashmap_init(&remotes_hash, remotes_hash_cmp, NULL, 0);
 155}
 156
 157static struct remote *make_remote(const char *name, int len)
 158{
 159        struct remote *ret, *replaced;
 160        struct remotes_hash_key lookup;
 161        struct hashmap_entry lookup_entry;
 162
 163        if (!len)
 164                len = strlen(name);
 165
 166        init_remotes_hash();
 167        lookup.str = name;
 168        lookup.len = len;
 169        hashmap_entry_init(&lookup_entry, memhash(name, len));
 170
 171        if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 172                return ret;
 173
 174        ret = xcalloc(1, sizeof(struct remote));
 175        ret->prune = -1;  /* unspecified */
 176        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 177        remotes[remotes_nr++] = ret;
 178        ret->name = xstrndup(name, len);
 179
 180        hashmap_entry_init(ret, lookup_entry.hash);
 181        replaced = hashmap_put(&remotes_hash, ret);
 182        assert(replaced == NULL);  /* no previous entry overwritten */
 183        return ret;
 184}
 185
 186static void add_merge(struct branch *branch, const char *name)
 187{
 188        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 189                   branch->merge_alloc);
 190        branch->merge_name[branch->merge_nr++] = name;
 191}
 192
 193static struct branch *make_branch(const char *name, int len)
 194{
 195        struct branch *ret;
 196        int i;
 197
 198        for (i = 0; i < branches_nr; i++) {
 199                if (len ? (!strncmp(name, branches[i]->name, len) &&
 200                           !branches[i]->name[len]) :
 201                    !strcmp(name, branches[i]->name))
 202                        return branches[i];
 203        }
 204
 205        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 206        ret = xcalloc(1, sizeof(struct branch));
 207        branches[branches_nr++] = ret;
 208        if (len)
 209                ret->name = xstrndup(name, len);
 210        else
 211                ret->name = xstrdup(name);
 212        ret->refname = xstrfmt("refs/heads/%s", ret->name);
 213
 214        return ret;
 215}
 216
 217static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 218{
 219        struct rewrite *ret;
 220        int i;
 221
 222        for (i = 0; i < r->rewrite_nr; i++) {
 223                if (len
 224                    ? (len == r->rewrite[i]->baselen &&
 225                       !strncmp(base, r->rewrite[i]->base, len))
 226                    : !strcmp(base, r->rewrite[i]->base))
 227                        return r->rewrite[i];
 228        }
 229
 230        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 231        ret = xcalloc(1, sizeof(struct rewrite));
 232        r->rewrite[r->rewrite_nr++] = ret;
 233        if (len) {
 234                ret->base = xstrndup(base, len);
 235                ret->baselen = len;
 236        }
 237        else {
 238                ret->base = xstrdup(base);
 239                ret->baselen = strlen(base);
 240        }
 241        return ret;
 242}
 243
 244static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 245{
 246        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 247        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 248        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 249        rewrite->instead_of_nr++;
 250}
 251
 252static const char *skip_spaces(const char *s)
 253{
 254        while (isspace(*s))
 255                s++;
 256        return s;
 257}
 258
 259static void read_remotes_file(struct remote *remote)
 260{
 261        struct strbuf buf = STRBUF_INIT;
 262        FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");
 263
 264        if (!f)
 265                return;
 266        remote->configured_in_repo = 1;
 267        remote->origin = REMOTE_REMOTES;
 268        while (strbuf_getline(&buf, f) != EOF) {
 269                const char *v;
 270
 271                strbuf_rtrim(&buf);
 272
 273                if (skip_prefix(buf.buf, "URL:", &v))
 274                        add_url_alias(remote, xstrdup(skip_spaces(v)));
 275                else if (skip_prefix(buf.buf, "Push:", &v))
 276                        add_push_refspec(remote, xstrdup(skip_spaces(v)));
 277                else if (skip_prefix(buf.buf, "Pull:", &v))
 278                        add_fetch_refspec(remote, xstrdup(skip_spaces(v)));
 279        }
 280        strbuf_release(&buf);
 281        fclose(f);
 282}
 283
 284static void read_branches_file(struct remote *remote)
 285{
 286        char *frag;
 287        struct strbuf buf = STRBUF_INIT;
 288        FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");
 289
 290        if (!f)
 291                return;
 292
 293        strbuf_getline_lf(&buf, f);
 294        fclose(f);
 295        strbuf_trim(&buf);
 296        if (!buf.len) {
 297                strbuf_release(&buf);
 298                return;
 299        }
 300
 301        remote->configured_in_repo = 1;
 302        remote->origin = REMOTE_BRANCHES;
 303
 304        /*
 305         * The branches file would have URL and optionally
 306         * #branch specified.  The "master" (or specified) branch is
 307         * fetched and stored in the local branch matching the
 308         * remote name.
 309         */
 310        frag = strchr(buf.buf, '#');
 311        if (frag)
 312                *(frag++) = '\0';
 313        else
 314                frag = "master";
 315
 316        add_url_alias(remote, strbuf_detach(&buf, NULL));
 317        add_fetch_refspec(remote, xstrfmt("refs/heads/%s:refs/heads/%s",
 318                                          frag, remote->name));
 319
 320        /*
 321         * Cogito compatible push: push current HEAD to remote #branch
 322         * (master if missing)
 323         */
 324        add_push_refspec(remote, xstrfmt("HEAD:refs/heads/%s", frag));
 325        remote->fetch_tags = 1; /* always auto-follow */
 326}
 327
 328static int handle_config(const char *key, const char *value, void *cb)
 329{
 330        const char *name;
 331        int namelen;
 332        const char *subkey;
 333        struct remote *remote;
 334        struct branch *branch;
 335        if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 336                if (!name)
 337                        return 0;
 338                branch = make_branch(name, namelen);
 339                if (!strcmp(subkey, "remote")) {
 340                        return git_config_string(&branch->remote_name, key, value);
 341                } else if (!strcmp(subkey, "pushremote")) {
 342                        return git_config_string(&branch->pushremote_name, key, value);
 343                } else if (!strcmp(subkey, "merge")) {
 344                        if (!value)
 345                                return config_error_nonbool(key);
 346                        add_merge(branch, xstrdup(value));
 347                }
 348                return 0;
 349        }
 350        if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 351                struct rewrite *rewrite;
 352                if (!name)
 353                        return 0;
 354                if (!strcmp(subkey, "insteadof")) {
 355                        rewrite = make_rewrite(&rewrites, name, namelen);
 356                        if (!value)
 357                                return config_error_nonbool(key);
 358                        add_instead_of(rewrite, xstrdup(value));
 359                } else if (!strcmp(subkey, "pushinsteadof")) {
 360                        rewrite = make_rewrite(&rewrites_push, name, namelen);
 361                        if (!value)
 362                                return config_error_nonbool(key);
 363                        add_instead_of(rewrite, xstrdup(value));
 364                }
 365        }
 366
 367        if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 368                return 0;
 369
 370        /* Handle remote.* variables */
 371        if (!name && !strcmp(subkey, "pushdefault"))
 372                return git_config_string(&pushremote_name, key, value);
 373
 374        if (!name)
 375                return 0;
 376        /* Handle remote.<name>.* variables */
 377        if (*name == '/') {
 378                warning("Config remote shorthand cannot begin with '/': %s",
 379                        name);
 380                return 0;
 381        }
 382        remote = make_remote(name, namelen);
 383        remote->origin = REMOTE_CONFIG;
 384        if (current_config_scope() == CONFIG_SCOPE_REPO)
 385                remote->configured_in_repo = 1;
 386        if (!strcmp(subkey, "mirror"))
 387                remote->mirror = git_config_bool(key, value);
 388        else if (!strcmp(subkey, "skipdefaultupdate"))
 389                remote->skip_default_update = git_config_bool(key, value);
 390        else if (!strcmp(subkey, "skipfetchall"))
 391                remote->skip_default_update = git_config_bool(key, value);
 392        else if (!strcmp(subkey, "prune"))
 393                remote->prune = git_config_bool(key, value);
 394        else if (!strcmp(subkey, "url")) {
 395                const char *v;
 396                if (git_config_string(&v, key, value))
 397                        return -1;
 398                add_url(remote, v);
 399        } else if (!strcmp(subkey, "pushurl")) {
 400                const char *v;
 401                if (git_config_string(&v, key, value))
 402                        return -1;
 403                add_pushurl(remote, v);
 404        } else if (!strcmp(subkey, "push")) {
 405                const char *v;
 406                if (git_config_string(&v, key, value))
 407                        return -1;
 408                add_push_refspec(remote, v);
 409        } else if (!strcmp(subkey, "fetch")) {
 410                const char *v;
 411                if (git_config_string(&v, key, value))
 412                        return -1;
 413                add_fetch_refspec(remote, v);
 414        } else if (!strcmp(subkey, "receivepack")) {
 415                const char *v;
 416                if (git_config_string(&v, key, value))
 417                        return -1;
 418                if (!remote->receivepack)
 419                        remote->receivepack = v;
 420                else
 421                        error("more than one receivepack given, using the first");
 422        } else if (!strcmp(subkey, "uploadpack")) {
 423                const char *v;
 424                if (git_config_string(&v, key, value))
 425                        return -1;
 426                if (!remote->uploadpack)
 427                        remote->uploadpack = v;
 428                else
 429                        error("more than one uploadpack given, using the first");
 430        } else if (!strcmp(subkey, "tagopt")) {
 431                if (!strcmp(value, "--no-tags"))
 432                        remote->fetch_tags = -1;
 433                else if (!strcmp(value, "--tags"))
 434                        remote->fetch_tags = 2;
 435        } else if (!strcmp(subkey, "proxy")) {
 436                return git_config_string((const char **)&remote->http_proxy,
 437                                         key, value);
 438        } else if (!strcmp(subkey, "proxyauthmethod")) {
 439                return git_config_string((const char **)&remote->http_proxy_authmethod,
 440                                         key, value);
 441        } else if (!strcmp(subkey, "vcs")) {
 442                return git_config_string(&remote->foreign_vcs, key, value);
 443        }
 444        return 0;
 445}
 446
 447static void alias_all_urls(void)
 448{
 449        int i, j;
 450        for (i = 0; i < remotes_nr; i++) {
 451                int add_pushurl_aliases;
 452                if (!remotes[i])
 453                        continue;
 454                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 455                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 456                }
 457                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 458                for (j = 0; j < remotes[i]->url_nr; j++) {
 459                        if (add_pushurl_aliases)
 460                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 461                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 462                }
 463        }
 464}
 465
 466static void read_config(void)
 467{
 468        static int loaded;
 469        int flag;
 470
 471        if (loaded)
 472                return;
 473        loaded = 1;
 474
 475        current_branch = NULL;
 476        if (startup_info->have_repository) {
 477                const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
 478                if (head_ref && (flag & REF_ISSYMREF) &&
 479                    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 480                        current_branch = make_branch(head_ref, 0);
 481                }
 482        }
 483        git_config(handle_config, NULL);
 484        alias_all_urls();
 485}
 486
 487static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 488{
 489        int i;
 490        struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 491
 492        for (i = 0; i < nr_refspec; i++) {
 493                size_t llen;
 494                int is_glob;
 495                const char *lhs, *rhs;
 496                int flags;
 497
 498                is_glob = 0;
 499
 500                lhs = refspec[i];
 501                if (*lhs == '+') {
 502                        rs[i].force = 1;
 503                        lhs++;
 504                }
 505
 506                rhs = strrchr(lhs, ':');
 507
 508                /*
 509                 * Before going on, special case ":" (or "+:") as a refspec
 510                 * for pushing matching refs.
 511                 */
 512                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 513                        rs[i].matching = 1;
 514                        continue;
 515                }
 516
 517                if (rhs) {
 518                        size_t rlen = strlen(++rhs);
 519                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 520                        rs[i].dst = xstrndup(rhs, rlen);
 521                }
 522
 523                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 524                if (1 <= llen && memchr(lhs, '*', llen)) {
 525                        if ((rhs && !is_glob) || (!rhs && fetch))
 526                                goto invalid;
 527                        is_glob = 1;
 528                } else if (rhs && is_glob) {
 529                        goto invalid;
 530                }
 531
 532                rs[i].pattern = is_glob;
 533                rs[i].src = xstrndup(lhs, llen);
 534                flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 535
 536                if (fetch) {
 537                        struct object_id unused;
 538
 539                        /* LHS */
 540                        if (!*rs[i].src)
 541                                ; /* empty is ok; it means "HEAD" */
 542                        else if (llen == GIT_SHA1_HEXSZ && !get_oid_hex(rs[i].src, &unused))
 543                                rs[i].exact_sha1 = 1; /* ok */
 544                        else if (!check_refname_format(rs[i].src, flags))
 545                                ; /* valid looking ref is ok */
 546                        else
 547                                goto invalid;
 548                        /* RHS */
 549                        if (!rs[i].dst)
 550                                ; /* missing is ok; it is the same as empty */
 551                        else if (!*rs[i].dst)
 552                                ; /* empty is ok; it means "do not store" */
 553                        else if (!check_refname_format(rs[i].dst, flags))
 554                                ; /* valid looking ref is ok */
 555                        else
 556                                goto invalid;
 557                } else {
 558                        /*
 559                         * LHS
 560                         * - empty is allowed; it means delete.
 561                         * - when wildcarded, it must be a valid looking ref.
 562                         * - otherwise, it must be an extended SHA-1, but
 563                         *   there is no existing way to validate this.
 564                         */
 565                        if (!*rs[i].src)
 566                                ; /* empty is ok */
 567                        else if (is_glob) {
 568                                if (check_refname_format(rs[i].src, flags))
 569                                        goto invalid;
 570                        }
 571                        else
 572                                ; /* anything goes, for now */
 573                        /*
 574                         * RHS
 575                         * - missing is allowed, but LHS then must be a
 576                         *   valid looking ref.
 577                         * - empty is not allowed.
 578                         * - otherwise it must be a valid looking ref.
 579                         */
 580                        if (!rs[i].dst) {
 581                                if (check_refname_format(rs[i].src, flags))
 582                                        goto invalid;
 583                        } else if (!*rs[i].dst) {
 584                                goto invalid;
 585                        } else {
 586                                if (check_refname_format(rs[i].dst, flags))
 587                                        goto invalid;
 588                        }
 589                }
 590        }
 591        return rs;
 592
 593 invalid:
 594        if (verify) {
 595                /*
 596                 * nr_refspec must be greater than zero and i must be valid
 597                 * since it is only possible to reach this point from within
 598                 * the for loop above.
 599                 */
 600                free_refspec(i+1, rs);
 601                return NULL;
 602        }
 603        die("Invalid refspec '%s'", refspec[i]);
 604}
 605
 606int valid_fetch_refspec(const char *fetch_refspec_str)
 607{
 608        struct refspec *refspec;
 609
 610        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 611        free_refspec(1, refspec);
 612        return !!refspec;
 613}
 614
 615struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 616{
 617        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 618}
 619
 620struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 621{
 622        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 623}
 624
 625void free_refspec(int nr_refspec, struct refspec *refspec)
 626{
 627        int i;
 628
 629        if (!refspec)
 630                return;
 631
 632        for (i = 0; i < nr_refspec; i++) {
 633                free(refspec[i].src);
 634                free(refspec[i].dst);
 635        }
 636        free(refspec);
 637}
 638
 639static int valid_remote_nick(const char *name)
 640{
 641        if (!name[0] || is_dot_or_dotdot(name))
 642                return 0;
 643
 644        /* remote nicknames cannot contain slashes */
 645        while (*name)
 646                if (is_dir_sep(*name++))
 647                        return 0;
 648        return 1;
 649}
 650
 651const char *remote_for_branch(struct branch *branch, int *explicit)
 652{
 653        if (branch && branch->remote_name) {
 654                if (explicit)
 655                        *explicit = 1;
 656                return branch->remote_name;
 657        }
 658        if (explicit)
 659                *explicit = 0;
 660        return "origin";
 661}
 662
 663const char *pushremote_for_branch(struct branch *branch, int *explicit)
 664{
 665        if (branch && branch->pushremote_name) {
 666                if (explicit)
 667                        *explicit = 1;
 668                return branch->pushremote_name;
 669        }
 670        if (pushremote_name) {
 671                if (explicit)
 672                        *explicit = 1;
 673                return pushremote_name;
 674        }
 675        return remote_for_branch(branch, explicit);
 676}
 677
 678const char *remote_ref_for_branch(struct branch *branch, int for_push,
 679                                  int *explicit)
 680{
 681        if (branch) {
 682                if (!for_push) {
 683                        if (branch->merge_nr) {
 684                                if (explicit)
 685                                        *explicit = 1;
 686                                return branch->merge_name[0];
 687                        }
 688                } else {
 689                        const char *dst, *remote_name =
 690                                pushremote_for_branch(branch, NULL);
 691                        struct remote *remote = remote_get(remote_name);
 692
 693                        if (remote && remote->push_refspec_nr &&
 694                            (dst = apply_refspecs(remote->push,
 695                                                  remote->push_refspec_nr,
 696                                                  branch->refname))) {
 697                                if (explicit)
 698                                        *explicit = 1;
 699                                return dst;
 700                        }
 701                }
 702        }
 703        if (explicit)
 704                *explicit = 0;
 705        return "";
 706}
 707
 708static struct remote *remote_get_1(const char *name,
 709                                   const char *(*get_default)(struct branch *, int *))
 710{
 711        struct remote *ret;
 712        int name_given = 0;
 713
 714        read_config();
 715
 716        if (name)
 717                name_given = 1;
 718        else
 719                name = get_default(current_branch, &name_given);
 720
 721        ret = make_remote(name, 0);
 722        if (valid_remote_nick(name) && have_git_dir()) {
 723                if (!valid_remote(ret))
 724                        read_remotes_file(ret);
 725                if (!valid_remote(ret))
 726                        read_branches_file(ret);
 727        }
 728        if (name_given && !valid_remote(ret))
 729                add_url_alias(ret, name);
 730        if (!valid_remote(ret))
 731                return NULL;
 732        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 733        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 734        return ret;
 735}
 736
 737struct remote *remote_get(const char *name)
 738{
 739        return remote_get_1(name, remote_for_branch);
 740}
 741
 742struct remote *pushremote_get(const char *name)
 743{
 744        return remote_get_1(name, pushremote_for_branch);
 745}
 746
 747int remote_is_configured(struct remote *remote, int in_repo)
 748{
 749        if (!remote)
 750                return 0;
 751        if (in_repo)
 752                return remote->configured_in_repo;
 753        return !!remote->origin;
 754}
 755
 756int for_each_remote(each_remote_fn fn, void *priv)
 757{
 758        int i, result = 0;
 759        read_config();
 760        for (i = 0; i < remotes_nr && !result; i++) {
 761                struct remote *r = remotes[i];
 762                if (!r)
 763                        continue;
 764                if (!r->fetch)
 765                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 766                                                       r->fetch_refspec);
 767                if (!r->push)
 768                        r->push = parse_push_refspec(r->push_refspec_nr,
 769                                                     r->push_refspec);
 770                result = fn(r, priv);
 771        }
 772        return result;
 773}
 774
 775static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 776{
 777        if (strcmp(ref1->name, ref2->name)) {
 778                if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 779                    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 780                        die(_("Cannot fetch both %s and %s to %s"),
 781                            ref1->name, ref2->name, ref2->peer_ref->name);
 782                } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 783                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 784                        warning(_("%s usually tracks %s, not %s"),
 785                                ref2->peer_ref->name, ref2->name, ref1->name);
 786                } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 787                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 788                        die(_("%s tracks both %s and %s"),
 789                            ref2->peer_ref->name, ref1->name, ref2->name);
 790                } else {
 791                        /*
 792                         * This last possibility doesn't occur because
 793                         * FETCH_HEAD_IGNORE entries always appear at
 794                         * the end of the list.
 795                         */
 796                        die(_("Internal error"));
 797                }
 798        }
 799        free(ref2->peer_ref);
 800        free(ref2);
 801}
 802
 803struct ref *ref_remove_duplicates(struct ref *ref_map)
 804{
 805        struct string_list refs = STRING_LIST_INIT_NODUP;
 806        struct ref *retval = NULL;
 807        struct ref **p = &retval;
 808
 809        while (ref_map) {
 810                struct ref *ref = ref_map;
 811
 812                ref_map = ref_map->next;
 813                ref->next = NULL;
 814
 815                if (!ref->peer_ref) {
 816                        *p = ref;
 817                        p = &ref->next;
 818                } else {
 819                        struct string_list_item *item =
 820                                string_list_insert(&refs, ref->peer_ref->name);
 821
 822                        if (item->util) {
 823                                /* Entry already existed */
 824                                handle_duplicate((struct ref *)item->util, ref);
 825                        } else {
 826                                *p = ref;
 827                                p = &ref->next;
 828                                item->util = ref;
 829                        }
 830                }
 831        }
 832
 833        string_list_clear(&refs, 0);
 834        return retval;
 835}
 836
 837int remote_has_url(struct remote *remote, const char *url)
 838{
 839        int i;
 840        for (i = 0; i < remote->url_nr; i++) {
 841                if (!strcmp(remote->url[i], url))
 842                        return 1;
 843        }
 844        return 0;
 845}
 846
 847static int match_name_with_pattern(const char *key, const char *name,
 848                                   const char *value, char **result)
 849{
 850        const char *kstar = strchr(key, '*');
 851        size_t klen;
 852        size_t ksuffixlen;
 853        size_t namelen;
 854        int ret;
 855        if (!kstar)
 856                die("Key '%s' of pattern had no '*'", key);
 857        klen = kstar - key;
 858        ksuffixlen = strlen(kstar + 1);
 859        namelen = strlen(name);
 860        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 861                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 862        if (ret && value) {
 863                struct strbuf sb = STRBUF_INIT;
 864                const char *vstar = strchr(value, '*');
 865                if (!vstar)
 866                        die("Value '%s' of pattern has no '*'", value);
 867                strbuf_add(&sb, value, vstar - value);
 868                strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 869                strbuf_addstr(&sb, vstar + 1);
 870                *result = strbuf_detach(&sb, NULL);
 871        }
 872        return ret;
 873}
 874
 875static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 876{
 877        int i;
 878        int find_src = !query->src;
 879
 880        if (find_src && !query->dst)
 881                error("query_refspecs_multiple: need either src or dst");
 882
 883        for (i = 0; i < ref_count; i++) {
 884                struct refspec *refspec = &refs[i];
 885                const char *key = find_src ? refspec->dst : refspec->src;
 886                const char *value = find_src ? refspec->src : refspec->dst;
 887                const char *needle = find_src ? query->dst : query->src;
 888                char **result = find_src ? &query->src : &query->dst;
 889
 890                if (!refspec->dst)
 891                        continue;
 892                if (refspec->pattern) {
 893                        if (match_name_with_pattern(key, needle, value, result))
 894                                string_list_append_nodup(results, *result);
 895                } else if (!strcmp(needle, key)) {
 896                        string_list_append(results, value);
 897                }
 898        }
 899}
 900
 901int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 902{
 903        int i;
 904        int find_src = !query->src;
 905        const char *needle = find_src ? query->dst : query->src;
 906        char **result = find_src ? &query->src : &query->dst;
 907
 908        if (find_src && !query->dst)
 909                return error("query_refspecs: need either src or dst");
 910
 911        for (i = 0; i < ref_count; i++) {
 912                struct refspec *refspec = &refs[i];
 913                const char *key = find_src ? refspec->dst : refspec->src;
 914                const char *value = find_src ? refspec->src : refspec->dst;
 915
 916                if (!refspec->dst)
 917                        continue;
 918                if (refspec->pattern) {
 919                        if (match_name_with_pattern(key, needle, value, result)) {
 920                                query->force = refspec->force;
 921                                return 0;
 922                        }
 923                } else if (!strcmp(needle, key)) {
 924                        *result = xstrdup(value);
 925                        query->force = refspec->force;
 926                        return 0;
 927                }
 928        }
 929        return -1;
 930}
 931
 932char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 933                     const char *name)
 934{
 935        struct refspec query;
 936
 937        memset(&query, 0, sizeof(struct refspec));
 938        query.src = (char *)name;
 939
 940        if (query_refspecs(refspecs, nr_refspec, &query))
 941                return NULL;
 942
 943        return query.dst;
 944}
 945
 946int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 947{
 948        return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 949}
 950
 951static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 952                const char *name)
 953{
 954        size_t len = strlen(name);
 955        struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 956        memcpy(ref->name, prefix, prefixlen);
 957        memcpy(ref->name + prefixlen, name, len);
 958        return ref;
 959}
 960
 961struct ref *alloc_ref(const char *name)
 962{
 963        return alloc_ref_with_prefix("", 0, name);
 964}
 965
 966struct ref *copy_ref(const struct ref *ref)
 967{
 968        struct ref *cpy;
 969        size_t len;
 970        if (!ref)
 971                return NULL;
 972        len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 973        cpy = xmalloc(len);
 974        memcpy(cpy, ref, len);
 975        cpy->next = NULL;
 976        cpy->symref = xstrdup_or_null(ref->symref);
 977        cpy->remote_status = xstrdup_or_null(ref->remote_status);
 978        cpy->peer_ref = copy_ref(ref->peer_ref);
 979        return cpy;
 980}
 981
 982struct ref *copy_ref_list(const struct ref *ref)
 983{
 984        struct ref *ret = NULL;
 985        struct ref **tail = &ret;
 986        while (ref) {
 987                *tail = copy_ref(ref);
 988                ref = ref->next;
 989                tail = &((*tail)->next);
 990        }
 991        return ret;
 992}
 993
 994static void free_ref(struct ref *ref)
 995{
 996        if (!ref)
 997                return;
 998        free_ref(ref->peer_ref);
 999        free(ref->remote_status);
1000        free(ref->symref);
1001        free(ref);
1002}
1003
1004void free_refs(struct ref *ref)
1005{
1006        struct ref *next;
1007        while (ref) {
1008                next = ref->next;
1009                free_ref(ref);
1010                ref = next;
1011        }
1012}
1013
1014int ref_compare_name(const void *va, const void *vb)
1015{
1016        const struct ref *a = va, *b = vb;
1017        return strcmp(a->name, b->name);
1018}
1019
1020static void *ref_list_get_next(const void *a)
1021{
1022        return ((const struct ref *)a)->next;
1023}
1024
1025static void ref_list_set_next(void *a, void *next)
1026{
1027        ((struct ref *)a)->next = next;
1028}
1029
1030void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1031{
1032        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1033}
1034
1035int count_refspec_match(const char *pattern,
1036                        struct ref *refs,
1037                        struct ref **matched_ref)
1038{
1039        int patlen = strlen(pattern);
1040        struct ref *matched_weak = NULL;
1041        struct ref *matched = NULL;
1042        int weak_match = 0;
1043        int match = 0;
1044
1045        for (weak_match = match = 0; refs; refs = refs->next) {
1046                char *name = refs->name;
1047                int namelen = strlen(name);
1048
1049                if (!refname_match(pattern, name))
1050                        continue;
1051
1052                /* A match is "weak" if it is with refs outside
1053                 * heads or tags, and did not specify the pattern
1054                 * in full (e.g. "refs/remotes/origin/master") or at
1055                 * least from the toplevel (e.g. "remotes/origin/master");
1056                 * otherwise "git push $URL master" would result in
1057                 * ambiguity between remotes/origin/master and heads/master
1058                 * at the remote site.
1059                 */
1060                if (namelen != patlen &&
1061                    patlen != namelen - 5 &&
1062                    !starts_with(name, "refs/heads/") &&
1063                    !starts_with(name, "refs/tags/")) {
1064                        /* We want to catch the case where only weak
1065                         * matches are found and there are multiple
1066                         * matches, and where more than one strong
1067                         * matches are found, as ambiguous.  One
1068                         * strong match with zero or more weak matches
1069                         * are acceptable as a unique match.
1070                         */
1071                        matched_weak = refs;
1072                        weak_match++;
1073                }
1074                else {
1075                        matched = refs;
1076                        match++;
1077                }
1078        }
1079        if (!matched) {
1080                if (matched_ref)
1081                        *matched_ref = matched_weak;
1082                return weak_match;
1083        }
1084        else {
1085                if (matched_ref)
1086                        *matched_ref = matched;
1087                return match;
1088        }
1089}
1090
1091static void tail_link_ref(struct ref *ref, struct ref ***tail)
1092{
1093        **tail = ref;
1094        while (ref->next)
1095                ref = ref->next;
1096        *tail = &ref->next;
1097}
1098
1099static struct ref *alloc_delete_ref(void)
1100{
1101        struct ref *ref = alloc_ref("(delete)");
1102        oidclr(&ref->new_oid);
1103        return ref;
1104}
1105
1106static int try_explicit_object_name(const char *name,
1107                                    struct ref **match)
1108{
1109        struct object_id oid;
1110
1111        if (!*name) {
1112                if (match)
1113                        *match = alloc_delete_ref();
1114                return 0;
1115        }
1116
1117        if (get_oid(name, &oid))
1118                return -1;
1119
1120        if (match) {
1121                *match = alloc_ref(name);
1122                oidcpy(&(*match)->new_oid, &oid);
1123        }
1124        return 0;
1125}
1126
1127static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1128{
1129        struct ref *ret = alloc_ref(name);
1130        tail_link_ref(ret, tail);
1131        return ret;
1132}
1133
1134static char *guess_ref(const char *name, struct ref *peer)
1135{
1136        struct strbuf buf = STRBUF_INIT;
1137
1138        const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1139                                           NULL, NULL);
1140        if (!r)
1141                return NULL;
1142
1143        if (starts_with(r, "refs/heads/"))
1144                strbuf_addstr(&buf, "refs/heads/");
1145        else if (starts_with(r, "refs/tags/"))
1146                strbuf_addstr(&buf, "refs/tags/");
1147        else
1148                return NULL;
1149
1150        strbuf_addstr(&buf, name);
1151        return strbuf_detach(&buf, NULL);
1152}
1153
1154static int match_explicit_lhs(struct ref *src,
1155                              struct refspec *rs,
1156                              struct ref **match,
1157                              int *allocated_match)
1158{
1159        switch (count_refspec_match(rs->src, src, match)) {
1160        case 1:
1161                if (allocated_match)
1162                        *allocated_match = 0;
1163                return 0;
1164        case 0:
1165                /* The source could be in the get_sha1() format
1166                 * not a reference name.  :refs/other is a
1167                 * way to delete 'other' ref at the remote end.
1168                 */
1169                if (try_explicit_object_name(rs->src, match) < 0)
1170                        return error("src refspec %s does not match any.", rs->src);
1171                if (allocated_match)
1172                        *allocated_match = 1;
1173                return 0;
1174        default:
1175                return error("src refspec %s matches more than one.", rs->src);
1176        }
1177}
1178
1179static int match_explicit(struct ref *src, struct ref *dst,
1180                          struct ref ***dst_tail,
1181                          struct refspec *rs)
1182{
1183        struct ref *matched_src, *matched_dst;
1184        int allocated_src;
1185
1186        const char *dst_value = rs->dst;
1187        char *dst_guess;
1188
1189        if (rs->pattern || rs->matching)
1190                return 0;
1191
1192        matched_src = matched_dst = NULL;
1193        if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1194                return -1;
1195
1196        if (!dst_value) {
1197                int flag;
1198
1199                dst_value = resolve_ref_unsafe(matched_src->name,
1200                                               RESOLVE_REF_READING,
1201                                               NULL, &flag);
1202                if (!dst_value ||
1203                    ((flag & REF_ISSYMREF) &&
1204                     !starts_with(dst_value, "refs/heads/")))
1205                        die("%s cannot be resolved to branch.",
1206                            matched_src->name);
1207        }
1208
1209        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1210        case 1:
1211                break;
1212        case 0:
1213                if (starts_with(dst_value, "refs/"))
1214                        matched_dst = make_linked_ref(dst_value, dst_tail);
1215                else if (is_null_oid(&matched_src->new_oid))
1216                        error("unable to delete '%s': remote ref does not exist",
1217                              dst_value);
1218                else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1219                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1220                        free(dst_guess);
1221                } else
1222                        error("unable to push to unqualified destination: %s\n"
1223                              "The destination refspec neither matches an "
1224                              "existing ref on the remote nor\n"
1225                              "begins with refs/, and we are unable to "
1226                              "guess a prefix based on the source ref.",
1227                              dst_value);
1228                break;
1229        default:
1230                matched_dst = NULL;
1231                error("dst refspec %s matches more than one.",
1232                      dst_value);
1233                break;
1234        }
1235        if (!matched_dst)
1236                return -1;
1237        if (matched_dst->peer_ref)
1238                return error("dst ref %s receives from more than one src.",
1239                      matched_dst->name);
1240        else {
1241                matched_dst->peer_ref = allocated_src ?
1242                                        matched_src :
1243                                        copy_ref(matched_src);
1244                matched_dst->force = rs->force;
1245        }
1246        return 0;
1247}
1248
1249static int match_explicit_refs(struct ref *src, struct ref *dst,
1250                               struct ref ***dst_tail, struct refspec *rs,
1251                               int rs_nr)
1252{
1253        int i, errs;
1254        for (i = errs = 0; i < rs_nr; i++)
1255                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1256        return errs;
1257}
1258
1259static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1260                int send_mirror, int direction, const struct refspec **ret_pat)
1261{
1262        const struct refspec *pat;
1263        char *name;
1264        int i;
1265        int matching_refs = -1;
1266        for (i = 0; i < rs_nr; i++) {
1267                if (rs[i].matching &&
1268                    (matching_refs == -1 || rs[i].force)) {
1269                        matching_refs = i;
1270                        continue;
1271                }
1272
1273                if (rs[i].pattern) {
1274                        const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1275                        int match;
1276                        if (direction == FROM_SRC)
1277                                match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1278                        else
1279                                match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1280                        if (match) {
1281                                matching_refs = i;
1282                                break;
1283                        }
1284                }
1285        }
1286        if (matching_refs == -1)
1287                return NULL;
1288
1289        pat = rs + matching_refs;
1290        if (pat->matching) {
1291                /*
1292                 * "matching refs"; traditionally we pushed everything
1293                 * including refs outside refs/heads/ hierarchy, but
1294                 * that does not make much sense these days.
1295                 */
1296                if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1297                        return NULL;
1298                name = xstrdup(ref->name);
1299        }
1300        if (ret_pat)
1301                *ret_pat = pat;
1302        return name;
1303}
1304
1305static struct ref **tail_ref(struct ref **head)
1306{
1307        struct ref **tail = head;
1308        while (*tail)
1309                tail = &((*tail)->next);
1310        return tail;
1311}
1312
1313struct tips {
1314        struct commit **tip;
1315        int nr, alloc;
1316};
1317
1318static void add_to_tips(struct tips *tips, const struct object_id *oid)
1319{
1320        struct commit *commit;
1321
1322        if (is_null_oid(oid))
1323                return;
1324        commit = lookup_commit_reference_gently(oid, 1);
1325        if (!commit || (commit->object.flags & TMP_MARK))
1326                return;
1327        commit->object.flags |= TMP_MARK;
1328        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1329        tips->tip[tips->nr++] = commit;
1330}
1331
1332static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1333{
1334        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1335        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1336        struct string_list_item *item;
1337        struct ref *ref;
1338        struct tips sent_tips;
1339
1340        /*
1341         * Collect everything we know they would have at the end of
1342         * this push, and collect all tags they have.
1343         */
1344        memset(&sent_tips, 0, sizeof(sent_tips));
1345        for (ref = *dst; ref; ref = ref->next) {
1346                if (ref->peer_ref &&
1347                    !is_null_oid(&ref->peer_ref->new_oid))
1348                        add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1349                else
1350                        add_to_tips(&sent_tips, &ref->old_oid);
1351                if (starts_with(ref->name, "refs/tags/"))
1352                        string_list_append(&dst_tag, ref->name);
1353        }
1354        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1355
1356        string_list_sort(&dst_tag);
1357
1358        /* Collect tags they do not have. */
1359        for (ref = src; ref; ref = ref->next) {
1360                if (!starts_with(ref->name, "refs/tags/"))
1361                        continue; /* not a tag */
1362                if (string_list_has_string(&dst_tag, ref->name))
1363                        continue; /* they already have it */
1364                if (sha1_object_info(ref->new_oid.hash, NULL) != OBJ_TAG)
1365                        continue; /* be conservative */
1366                item = string_list_append(&src_tag, ref->name);
1367                item->util = ref;
1368        }
1369        string_list_clear(&dst_tag, 0);
1370
1371        /*
1372         * At this point, src_tag lists tags that are missing from
1373         * dst, and sent_tips lists the tips we are pushing or those
1374         * that we know they already have. An element in the src_tag
1375         * that is an ancestor of any of the sent_tips needs to be
1376         * sent to the other side.
1377         */
1378        if (sent_tips.nr) {
1379                for_each_string_list_item(item, &src_tag) {
1380                        struct ref *ref = item->util;
1381                        struct ref *dst_ref;
1382                        struct commit *commit;
1383
1384                        if (is_null_oid(&ref->new_oid))
1385                                continue;
1386                        commit = lookup_commit_reference_gently(&ref->new_oid,
1387                                                                1);
1388                        if (!commit)
1389                                /* not pushing a commit, which is not an error */
1390                                continue;
1391
1392                        /*
1393                         * Is this tag, which they do not have, reachable from
1394                         * any of the commits we are sending?
1395                         */
1396                        if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1397                                continue;
1398
1399                        /* Add it in */
1400                        dst_ref = make_linked_ref(ref->name, dst_tail);
1401                        oidcpy(&dst_ref->new_oid, &ref->new_oid);
1402                        dst_ref->peer_ref = copy_ref(ref);
1403                }
1404        }
1405        string_list_clear(&src_tag, 0);
1406        free(sent_tips.tip);
1407}
1408
1409struct ref *find_ref_by_name(const struct ref *list, const char *name)
1410{
1411        for ( ; list; list = list->next)
1412                if (!strcmp(list->name, name))
1413                        return (struct ref *)list;
1414        return NULL;
1415}
1416
1417static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1418{
1419        for ( ; ref; ref = ref->next)
1420                string_list_append_nodup(ref_index, ref->name)->util = ref;
1421
1422        string_list_sort(ref_index);
1423}
1424
1425/*
1426 * Given only the set of local refs, sanity-check the set of push
1427 * refspecs. We can't catch all errors that match_push_refs would,
1428 * but we can catch some errors early before even talking to the
1429 * remote side.
1430 */
1431int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1432{
1433        struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1434        int ret = 0;
1435        int i;
1436
1437        for (i = 0; i < nr_refspec; i++) {
1438                struct refspec *rs = refspec + i;
1439
1440                if (rs->pattern || rs->matching)
1441                        continue;
1442
1443                ret |= match_explicit_lhs(src, rs, NULL, NULL);
1444        }
1445
1446        free_refspec(nr_refspec, refspec);
1447        return ret;
1448}
1449
1450/*
1451 * Given the set of refs the local repository has, the set of refs the
1452 * remote repository has, and the refspec used for push, determine
1453 * what remote refs we will update and with what value by setting
1454 * peer_ref (which object is being pushed) and force (if the push is
1455 * forced) in elements of "dst". The function may add new elements to
1456 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1457 */
1458int match_push_refs(struct ref *src, struct ref **dst,
1459                    int nr_refspec, const char **refspec, int flags)
1460{
1461        struct refspec *rs;
1462        int send_all = flags & MATCH_REFS_ALL;
1463        int send_mirror = flags & MATCH_REFS_MIRROR;
1464        int send_prune = flags & MATCH_REFS_PRUNE;
1465        int errs;
1466        static const char *default_refspec[] = { ":", NULL };
1467        struct ref *ref, **dst_tail = tail_ref(dst);
1468        struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1469
1470        if (!nr_refspec) {
1471                nr_refspec = 1;
1472                refspec = default_refspec;
1473        }
1474        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1475        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1476
1477        /* pick the remainder */
1478        for (ref = src; ref; ref = ref->next) {
1479                struct string_list_item *dst_item;
1480                struct ref *dst_peer;
1481                const struct refspec *pat = NULL;
1482                char *dst_name;
1483
1484                dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1485                if (!dst_name)
1486                        continue;
1487
1488                if (!dst_ref_index.nr)
1489                        prepare_ref_index(&dst_ref_index, *dst);
1490
1491                dst_item = string_list_lookup(&dst_ref_index, dst_name);
1492                dst_peer = dst_item ? dst_item->util : NULL;
1493                if (dst_peer) {
1494                        if (dst_peer->peer_ref)
1495                                /* We're already sending something to this ref. */
1496                                goto free_name;
1497                } else {
1498                        if (pat->matching && !(send_all || send_mirror))
1499                                /*
1500                                 * Remote doesn't have it, and we have no
1501                                 * explicit pattern, and we don't have
1502                                 * --all or --mirror.
1503                                 */
1504                                goto free_name;
1505
1506                        /* Create a new one and link it */
1507                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1508                        oidcpy(&dst_peer->new_oid, &ref->new_oid);
1509                        string_list_insert(&dst_ref_index,
1510                                dst_peer->name)->util = dst_peer;
1511                }
1512                dst_peer->peer_ref = copy_ref(ref);
1513                dst_peer->force = pat->force;
1514        free_name:
1515                free(dst_name);
1516        }
1517
1518        string_list_clear(&dst_ref_index, 0);
1519
1520        if (flags & MATCH_REFS_FOLLOW_TAGS)
1521                add_missing_tags(src, dst, &dst_tail);
1522
1523        if (send_prune) {
1524                struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1525                /* check for missing refs on the remote */
1526                for (ref = *dst; ref; ref = ref->next) {
1527                        char *src_name;
1528
1529                        if (ref->peer_ref)
1530                                /* We're already sending something to this ref. */
1531                                continue;
1532
1533                        src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1534                        if (src_name) {
1535                                if (!src_ref_index.nr)
1536                                        prepare_ref_index(&src_ref_index, src);
1537                                if (!string_list_has_string(&src_ref_index,
1538                                            src_name))
1539                                        ref->peer_ref = alloc_delete_ref();
1540                                free(src_name);
1541                        }
1542                }
1543                string_list_clear(&src_ref_index, 0);
1544        }
1545        if (errs)
1546                return -1;
1547        return 0;
1548}
1549
1550void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1551                             int force_update)
1552{
1553        struct ref *ref;
1554
1555        for (ref = remote_refs; ref; ref = ref->next) {
1556                int force_ref_update = ref->force || force_update;
1557                int reject_reason = 0;
1558
1559                if (ref->peer_ref)
1560                        oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1561                else if (!send_mirror)
1562                        continue;
1563
1564                ref->deletion = is_null_oid(&ref->new_oid);
1565                if (!ref->deletion &&
1566                        !oidcmp(&ref->old_oid, &ref->new_oid)) {
1567                        ref->status = REF_STATUS_UPTODATE;
1568                        continue;
1569                }
1570
1571                /*
1572                 * If the remote ref has moved and is now different
1573                 * from what we expect, reject any push.
1574                 *
1575                 * It also is an error if the user told us to check
1576                 * with the remote-tracking branch to find the value
1577                 * to expect, but we did not have such a tracking
1578                 * branch.
1579                 */
1580                if (ref->expect_old_sha1) {
1581                        if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
1582                                reject_reason = REF_STATUS_REJECT_STALE;
1583                        else
1584                                /* If the ref isn't stale then force the update. */
1585                                force_ref_update = 1;
1586                }
1587
1588                /*
1589                 * If the update isn't already rejected then check
1590                 * the usual "must fast-forward" rules.
1591                 *
1592                 * Decide whether an individual refspec A:B can be
1593                 * pushed.  The push will succeed if any of the
1594                 * following are true:
1595                 *
1596                 * (1) the remote reference B does not exist
1597                 *
1598                 * (2) the remote reference B is being removed (i.e.,
1599                 *     pushing :B where no source is specified)
1600                 *
1601                 * (3) the destination is not under refs/tags/, and
1602                 *     if the old and new value is a commit, the new
1603                 *     is a descendant of the old.
1604                 *
1605                 * (4) it is forced using the +A:B notation, or by
1606                 *     passing the --force argument
1607                 */
1608
1609                if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1610                        if (starts_with(ref->name, "refs/tags/"))
1611                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1612                        else if (!has_object_file(&ref->old_oid))
1613                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1614                        else if (!lookup_commit_reference_gently(&ref->old_oid, 1) ||
1615                                 !lookup_commit_reference_gently(&ref->new_oid, 1))
1616                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1617                        else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1618                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1619                }
1620
1621                /*
1622                 * "--force" will defeat any rejection implemented
1623                 * by the rules above.
1624                 */
1625                if (!force_ref_update)
1626                        ref->status = reject_reason;
1627                else if (reject_reason)
1628                        ref->forced_update = 1;
1629        }
1630}
1631
1632static void set_merge(struct branch *ret)
1633{
1634        struct remote *remote;
1635        char *ref;
1636        struct object_id oid;
1637        int i;
1638
1639        if (!ret)
1640                return; /* no branch */
1641        if (ret->merge)
1642                return; /* already run */
1643        if (!ret->remote_name || !ret->merge_nr) {
1644                /*
1645                 * no merge config; let's make sure we don't confuse callers
1646                 * with a non-zero merge_nr but a NULL merge
1647                 */
1648                ret->merge_nr = 0;
1649                return;
1650        }
1651
1652        remote = remote_get(ret->remote_name);
1653
1654        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1655        for (i = 0; i < ret->merge_nr; i++) {
1656                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1657                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1658                if (!remote_find_tracking(remote, ret->merge[i]) ||
1659                    strcmp(ret->remote_name, "."))
1660                        continue;
1661                if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1662                             &oid, &ref) == 1)
1663                        ret->merge[i]->dst = ref;
1664                else
1665                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1666        }
1667}
1668
1669struct branch *branch_get(const char *name)
1670{
1671        struct branch *ret;
1672
1673        read_config();
1674        if (!name || !*name || !strcmp(name, "HEAD"))
1675                ret = current_branch;
1676        else
1677                ret = make_branch(name, 0);
1678        set_merge(ret);
1679        return ret;
1680}
1681
1682int branch_has_merge_config(struct branch *branch)
1683{
1684        return branch && !!branch->merge;
1685}
1686
1687int branch_merge_matches(struct branch *branch,
1688                                 int i,
1689                                 const char *refname)
1690{
1691        if (!branch || i < 0 || i >= branch->merge_nr)
1692                return 0;
1693        return refname_match(branch->merge[i]->src, refname);
1694}
1695
1696__attribute__((format (printf,2,3)))
1697static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1698{
1699        if (err) {
1700                va_list ap;
1701                va_start(ap, fmt);
1702                strbuf_vaddf(err, fmt, ap);
1703                va_end(ap);
1704        }
1705        return NULL;
1706}
1707
1708const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1709{
1710        if (!branch)
1711                return error_buf(err, _("HEAD does not point to a branch"));
1712
1713        if (!branch->merge || !branch->merge[0]) {
1714                /*
1715                 * no merge config; is it because the user didn't define any,
1716                 * or because it is not a real branch, and get_branch
1717                 * auto-vivified it?
1718                 */
1719                if (!ref_exists(branch->refname))
1720                        return error_buf(err, _("no such branch: '%s'"),
1721                                         branch->name);
1722                return error_buf(err,
1723                                 _("no upstream configured for branch '%s'"),
1724                                 branch->name);
1725        }
1726
1727        if (!branch->merge[0]->dst)
1728                return error_buf(err,
1729                                 _("upstream branch '%s' not stored as a remote-tracking branch"),
1730                                 branch->merge[0]->src);
1731
1732        return branch->merge[0]->dst;
1733}
1734
1735static const char *tracking_for_push_dest(struct remote *remote,
1736                                          const char *refname,
1737                                          struct strbuf *err)
1738{
1739        char *ret;
1740
1741        ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1742        if (!ret)
1743                return error_buf(err,
1744                                 _("push destination '%s' on remote '%s' has no local tracking branch"),
1745                                 refname, remote->name);
1746        return ret;
1747}
1748
1749static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1750{
1751        struct remote *remote;
1752
1753        remote = remote_get(pushremote_for_branch(branch, NULL));
1754        if (!remote)
1755                return error_buf(err,
1756                                 _("branch '%s' has no remote for pushing"),
1757                                 branch->name);
1758
1759        if (remote->push_refspec_nr) {
1760                char *dst;
1761                const char *ret;
1762
1763                dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1764                                     branch->refname);
1765                if (!dst)
1766                        return error_buf(err,
1767                                         _("push refspecs for '%s' do not include '%s'"),
1768                                         remote->name, branch->name);
1769
1770                ret = tracking_for_push_dest(remote, dst, err);
1771                free(dst);
1772                return ret;
1773        }
1774
1775        if (remote->mirror)
1776                return tracking_for_push_dest(remote, branch->refname, err);
1777
1778        switch (push_default) {
1779        case PUSH_DEFAULT_NOTHING:
1780                return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1781
1782        case PUSH_DEFAULT_MATCHING:
1783        case PUSH_DEFAULT_CURRENT:
1784                return tracking_for_push_dest(remote, branch->refname, err);
1785
1786        case PUSH_DEFAULT_UPSTREAM:
1787                return branch_get_upstream(branch, err);
1788
1789        case PUSH_DEFAULT_UNSPECIFIED:
1790        case PUSH_DEFAULT_SIMPLE:
1791                {
1792                        const char *up, *cur;
1793
1794                        up = branch_get_upstream(branch, err);
1795                        if (!up)
1796                                return NULL;
1797                        cur = tracking_for_push_dest(remote, branch->refname, err);
1798                        if (!cur)
1799                                return NULL;
1800                        if (strcmp(cur, up))
1801                                return error_buf(err,
1802                                                 _("cannot resolve 'simple' push to a single destination"));
1803                        return cur;
1804                }
1805        }
1806
1807        die("BUG: unhandled push situation");
1808}
1809
1810const char *branch_get_push(struct branch *branch, struct strbuf *err)
1811{
1812        if (!branch)
1813                return error_buf(err, _("HEAD does not point to a branch"));
1814
1815        if (!branch->push_tracking_ref)
1816                branch->push_tracking_ref = branch_get_push_1(branch, err);
1817        return branch->push_tracking_ref;
1818}
1819
1820static int ignore_symref_update(const char *refname)
1821{
1822        int flag;
1823
1824        if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
1825                return 0; /* non-existing refs are OK */
1826        return (flag & REF_ISSYMREF);
1827}
1828
1829/*
1830 * Create and return a list of (struct ref) consisting of copies of
1831 * each remote_ref that matches refspec.  refspec must be a pattern.
1832 * Fill in the copies' peer_ref to describe the local tracking refs to
1833 * which they map.  Omit any references that would map to an existing
1834 * local symbolic ref.
1835 */
1836static struct ref *get_expanded_map(const struct ref *remote_refs,
1837                                    const struct refspec *refspec)
1838{
1839        const struct ref *ref;
1840        struct ref *ret = NULL;
1841        struct ref **tail = &ret;
1842
1843        for (ref = remote_refs; ref; ref = ref->next) {
1844                char *expn_name = NULL;
1845
1846                if (strchr(ref->name, '^'))
1847                        continue; /* a dereference item */
1848                if (match_name_with_pattern(refspec->src, ref->name,
1849                                            refspec->dst, &expn_name) &&
1850                    !ignore_symref_update(expn_name)) {
1851                        struct ref *cpy = copy_ref(ref);
1852
1853                        cpy->peer_ref = alloc_ref(expn_name);
1854                        if (refspec->force)
1855                                cpy->peer_ref->force = 1;
1856                        *tail = cpy;
1857                        tail = &cpy->next;
1858                }
1859                free(expn_name);
1860        }
1861
1862        return ret;
1863}
1864
1865static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1866{
1867        const struct ref *ref;
1868        for (ref = refs; ref; ref = ref->next) {
1869                if (refname_match(name, ref->name))
1870                        return ref;
1871        }
1872        return NULL;
1873}
1874
1875struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1876{
1877        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1878
1879        if (!ref)
1880                return NULL;
1881
1882        return copy_ref(ref);
1883}
1884
1885static struct ref *get_local_ref(const char *name)
1886{
1887        if (!name || name[0] == '\0')
1888                return NULL;
1889
1890        if (starts_with(name, "refs/"))
1891                return alloc_ref(name);
1892
1893        if (starts_with(name, "heads/") ||
1894            starts_with(name, "tags/") ||
1895            starts_with(name, "remotes/"))
1896                return alloc_ref_with_prefix("refs/", 5, name);
1897
1898        return alloc_ref_with_prefix("refs/heads/", 11, name);
1899}
1900
1901int get_fetch_map(const struct ref *remote_refs,
1902                  const struct refspec *refspec,
1903                  struct ref ***tail,
1904                  int missing_ok)
1905{
1906        struct ref *ref_map, **rmp;
1907
1908        if (refspec->pattern) {
1909                ref_map = get_expanded_map(remote_refs, refspec);
1910        } else {
1911                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1912
1913                if (refspec->exact_sha1) {
1914                        ref_map = alloc_ref(name);
1915                        get_oid_hex(name, &ref_map->old_oid);
1916                } else {
1917                        ref_map = get_remote_ref(remote_refs, name);
1918                }
1919                if (!missing_ok && !ref_map)
1920                        die("Couldn't find remote ref %s", name);
1921                if (ref_map) {
1922                        ref_map->peer_ref = get_local_ref(refspec->dst);
1923                        if (ref_map->peer_ref && refspec->force)
1924                                ref_map->peer_ref->force = 1;
1925                }
1926        }
1927
1928        for (rmp = &ref_map; *rmp; ) {
1929                if ((*rmp)->peer_ref) {
1930                        if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1931                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1932                                struct ref *ignore = *rmp;
1933                                error("* Ignoring funny ref '%s' locally",
1934                                      (*rmp)->peer_ref->name);
1935                                *rmp = (*rmp)->next;
1936                                free(ignore->peer_ref);
1937                                free(ignore);
1938                                continue;
1939                        }
1940                }
1941                rmp = &((*rmp)->next);
1942        }
1943
1944        if (ref_map)
1945                tail_link_ref(ref_map, tail);
1946
1947        return 0;
1948}
1949
1950int resolve_remote_symref(struct ref *ref, struct ref *list)
1951{
1952        if (!ref->symref)
1953                return 0;
1954        for (; list; list = list->next)
1955                if (!strcmp(ref->symref, list->name)) {
1956                        oidcpy(&ref->old_oid, &list->old_oid);
1957                        return 0;
1958                }
1959        return 1;
1960}
1961
1962static void unmark_and_free(struct commit_list *list, unsigned int mark)
1963{
1964        while (list) {
1965                struct commit *commit = pop_commit(&list);
1966                commit->object.flags &= ~mark;
1967        }
1968}
1969
1970int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1971{
1972        struct object *o;
1973        struct commit *old, *new;
1974        struct commit_list *list, *used;
1975        int found = 0;
1976
1977        /*
1978         * Both new and old must be commit-ish and new is descendant of
1979         * old.  Otherwise we require --force.
1980         */
1981        o = deref_tag(parse_object(old_oid), NULL, 0);
1982        if (!o || o->type != OBJ_COMMIT)
1983                return 0;
1984        old = (struct commit *) o;
1985
1986        o = deref_tag(parse_object(new_oid), NULL, 0);
1987        if (!o || o->type != OBJ_COMMIT)
1988                return 0;
1989        new = (struct commit *) o;
1990
1991        if (parse_commit(new) < 0)
1992                return 0;
1993
1994        used = list = NULL;
1995        commit_list_insert(new, &list);
1996        while (list) {
1997                new = pop_most_recent_commit(&list, TMP_MARK);
1998                commit_list_insert(new, &used);
1999                if (new == old) {
2000                        found = 1;
2001                        break;
2002                }
2003        }
2004        unmark_and_free(list, TMP_MARK);
2005        unmark_and_free(used, TMP_MARK);
2006        return found;
2007}
2008
2009/*
2010 * Compare a branch with its upstream, and save their differences (number
2011 * of commits) in *num_ours and *num_theirs. The name of the upstream branch
2012 * (or NULL if no upstream is defined) is returned via *upstream_name, if it
2013 * is not itself NULL.
2014 *
2015 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
2016 * upstream defined, or ref does not exist), 0 otherwise.
2017 */
2018int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
2019                       const char **upstream_name)
2020{
2021        struct object_id oid;
2022        struct commit *ours, *theirs;
2023        struct rev_info revs;
2024        const char *base;
2025        struct argv_array argv = ARGV_ARRAY_INIT;
2026
2027        /* Cannot stat unless we are marked to build on top of somebody else. */
2028        base = branch_get_upstream(branch, NULL);
2029        if (upstream_name)
2030                *upstream_name = base;
2031        if (!base)
2032                return -1;
2033
2034        /* Cannot stat if what we used to build on no longer exists */
2035        if (read_ref(base, &oid))
2036                return -1;
2037        theirs = lookup_commit_reference(&oid);
2038        if (!theirs)
2039                return -1;
2040
2041        if (read_ref(branch->refname, &oid))
2042                return -1;
2043        ours = lookup_commit_reference(&oid);
2044        if (!ours)
2045                return -1;
2046
2047        /* are we the same? */
2048        if (theirs == ours) {
2049                *num_theirs = *num_ours = 0;
2050                return 0;
2051        }
2052
2053        /* Run "rev-list --left-right ours...theirs" internally... */
2054        argv_array_push(&argv, ""); /* ignored */
2055        argv_array_push(&argv, "--left-right");
2056        argv_array_pushf(&argv, "%s...%s",
2057                         oid_to_hex(&ours->object.oid),
2058                         oid_to_hex(&theirs->object.oid));
2059        argv_array_push(&argv, "--");
2060
2061        init_revisions(&revs, NULL);
2062        setup_revisions(argv.argc, argv.argv, &revs, NULL);
2063        if (prepare_revision_walk(&revs))
2064                die("revision walk setup failed");
2065
2066        /* ... and count the commits on each side. */
2067        *num_ours = 0;
2068        *num_theirs = 0;
2069        while (1) {
2070                struct commit *c = get_revision(&revs);
2071                if (!c)
2072                        break;
2073                if (c->object.flags & SYMMETRIC_LEFT)
2074                        (*num_ours)++;
2075                else
2076                        (*num_theirs)++;
2077        }
2078
2079        /* clear object flags smudged by the above traversal */
2080        clear_commit_marks(ours, ALL_REV_FLAGS);
2081        clear_commit_marks(theirs, ALL_REV_FLAGS);
2082
2083        argv_array_clear(&argv);
2084        return 0;
2085}
2086
2087/*
2088 * Return true when there is anything to report, otherwise false.
2089 */
2090int format_tracking_info(struct branch *branch, struct strbuf *sb)
2091{
2092        int ours, theirs;
2093        const char *full_base;
2094        char *base;
2095        int upstream_is_gone = 0;
2096
2097        if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2098                if (!full_base)
2099                        return 0;
2100                upstream_is_gone = 1;
2101        }
2102
2103        base = shorten_unambiguous_ref(full_base, 0);
2104        if (upstream_is_gone) {
2105                strbuf_addf(sb,
2106                        _("Your branch is based on '%s', but the upstream is gone.\n"),
2107                        base);
2108                if (advice_status_hints)
2109                        strbuf_addstr(sb,
2110                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2111        } else if (!ours && !theirs) {
2112                strbuf_addf(sb,
2113                        _("Your branch is up to date with '%s'.\n"),
2114                        base);
2115        } else if (!theirs) {
2116                strbuf_addf(sb,
2117                        Q_("Your branch is ahead of '%s' by %d commit.\n",
2118                           "Your branch is ahead of '%s' by %d commits.\n",
2119                           ours),
2120                        base, ours);
2121                if (advice_status_hints)
2122                        strbuf_addstr(sb,
2123                                _("  (use \"git push\" to publish your local commits)\n"));
2124        } else if (!ours) {
2125                strbuf_addf(sb,
2126                        Q_("Your branch is behind '%s' by %d commit, "
2127                               "and can be fast-forwarded.\n",
2128                           "Your branch is behind '%s' by %d commits, "
2129                               "and can be fast-forwarded.\n",
2130                           theirs),
2131                        base, theirs);
2132                if (advice_status_hints)
2133                        strbuf_addstr(sb,
2134                                _("  (use \"git pull\" to update your local branch)\n"));
2135        } else {
2136                strbuf_addf(sb,
2137                        Q_("Your branch and '%s' have diverged,\n"
2138                               "and have %d and %d different commit each, "
2139                               "respectively.\n",
2140                           "Your branch and '%s' have diverged,\n"
2141                               "and have %d and %d different commits each, "
2142                               "respectively.\n",
2143                           ours + theirs),
2144                        base, ours, theirs);
2145                if (advice_status_hints)
2146                        strbuf_addstr(sb,
2147                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2148        }
2149        free(base);
2150        return 1;
2151}
2152
2153static int one_local_ref(const char *refname, const struct object_id *oid,
2154                         int flag, void *cb_data)
2155{
2156        struct ref ***local_tail = cb_data;
2157        struct ref *ref;
2158
2159        /* we already know it starts with refs/ to get here */
2160        if (check_refname_format(refname + 5, 0))
2161                return 0;
2162
2163        ref = alloc_ref(refname);
2164        oidcpy(&ref->new_oid, oid);
2165        **local_tail = ref;
2166        *local_tail = &ref->next;
2167        return 0;
2168}
2169
2170struct ref *get_local_heads(void)
2171{
2172        struct ref *local_refs = NULL, **local_tail = &local_refs;
2173
2174        for_each_ref(one_local_ref, &local_tail);
2175        return local_refs;
2176}
2177
2178struct ref *guess_remote_head(const struct ref *head,
2179                              const struct ref *refs,
2180                              int all)
2181{
2182        const struct ref *r;
2183        struct ref *list = NULL;
2184        struct ref **tail = &list;
2185
2186        if (!head)
2187                return NULL;
2188
2189        /*
2190         * Some transports support directly peeking at
2191         * where HEAD points; if that is the case, then
2192         * we don't have to guess.
2193         */
2194        if (head->symref)
2195                return copy_ref(find_ref_by_name(refs, head->symref));
2196
2197        /* If refs/heads/master could be right, it is. */
2198        if (!all) {
2199                r = find_ref_by_name(refs, "refs/heads/master");
2200                if (r && !oidcmp(&r->old_oid, &head->old_oid))
2201                        return copy_ref(r);
2202        }
2203
2204        /* Look for another ref that points there */
2205        for (r = refs; r; r = r->next) {
2206                if (r != head &&
2207                    starts_with(r->name, "refs/heads/") &&
2208                    !oidcmp(&r->old_oid, &head->old_oid)) {
2209                        *tail = copy_ref(r);
2210                        tail = &((*tail)->next);
2211                        if (!all)
2212                                break;
2213                }
2214        }
2215
2216        return list;
2217}
2218
2219struct stale_heads_info {
2220        struct string_list *ref_names;
2221        struct ref **stale_refs_tail;
2222        struct refspec *refs;
2223        int ref_count;
2224};
2225
2226static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2227                              int flags, void *cb_data)
2228{
2229        struct stale_heads_info *info = cb_data;
2230        struct string_list matches = STRING_LIST_INIT_DUP;
2231        struct refspec query;
2232        int i, stale = 1;
2233        memset(&query, 0, sizeof(struct refspec));
2234        query.dst = (char *)refname;
2235
2236        query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2237        if (matches.nr == 0)
2238                goto clean_exit; /* No matches */
2239
2240        /*
2241         * If we did find a suitable refspec and it's not a symref and
2242         * it's not in the list of refs that currently exist in that
2243         * remote, we consider it to be stale. In order to deal with
2244         * overlapping refspecs, we need to go over all of the
2245         * matching refs.
2246         */
2247        if (flags & REF_ISSYMREF)
2248                goto clean_exit;
2249
2250        for (i = 0; stale && i < matches.nr; i++)
2251                if (string_list_has_string(info->ref_names, matches.items[i].string))
2252                        stale = 0;
2253
2254        if (stale) {
2255                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2256                oidcpy(&ref->new_oid, oid);
2257        }
2258
2259clean_exit:
2260        string_list_clear(&matches, 0);
2261        return 0;
2262}
2263
2264struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2265{
2266        struct ref *ref, *stale_refs = NULL;
2267        struct string_list ref_names = STRING_LIST_INIT_NODUP;
2268        struct stale_heads_info info;
2269
2270        info.ref_names = &ref_names;
2271        info.stale_refs_tail = &stale_refs;
2272        info.refs = refs;
2273        info.ref_count = ref_count;
2274        for (ref = fetch_map; ref; ref = ref->next)
2275                string_list_append(&ref_names, ref->name);
2276        string_list_sort(&ref_names);
2277        for_each_ref(get_stale_heads_cb, &info);
2278        string_list_clear(&ref_names, 0);
2279        return stale_refs;
2280}
2281
2282/*
2283 * Compare-and-swap
2284 */
2285static void clear_cas_option(struct push_cas_option *cas)
2286{
2287        int i;
2288
2289        for (i = 0; i < cas->nr; i++)
2290                free(cas->entry[i].refname);
2291        free(cas->entry);
2292        memset(cas, 0, sizeof(*cas));
2293}
2294
2295static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2296                                      const char *refname,
2297                                      size_t refnamelen)
2298{
2299        struct push_cas *entry;
2300        ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2301        entry = &cas->entry[cas->nr++];
2302        memset(entry, 0, sizeof(*entry));
2303        entry->refname = xmemdupz(refname, refnamelen);
2304        return entry;
2305}
2306
2307static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2308{
2309        const char *colon;
2310        struct push_cas *entry;
2311
2312        if (unset) {
2313                /* "--no-<option>" */
2314                clear_cas_option(cas);
2315                return 0;
2316        }
2317
2318        if (!arg) {
2319                /* just "--<option>" */
2320                cas->use_tracking_for_rest = 1;
2321                return 0;
2322        }
2323
2324        /* "--<option>=refname" or "--<option>=refname:value" */
2325        colon = strchrnul(arg, ':');
2326        entry = add_cas_entry(cas, arg, colon - arg);
2327        if (!*colon)
2328                entry->use_tracking = 1;
2329        else if (!colon[1])
2330                oidclr(&entry->expect);
2331        else if (get_oid(colon + 1, &entry->expect))
2332                return error("cannot parse expected object name '%s'", colon + 1);
2333        return 0;
2334}
2335
2336int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2337{
2338        return parse_push_cas_option(opt->value, arg, unset);
2339}
2340
2341int is_empty_cas(const struct push_cas_option *cas)
2342{
2343        return !cas->use_tracking_for_rest && !cas->nr;
2344}
2345
2346/*
2347 * Look at remote.fetch refspec and see if we have a remote
2348 * tracking branch for the refname there.  Fill its current
2349 * value in sha1[].
2350 * If we cannot do so, return negative to signal an error.
2351 */
2352static int remote_tracking(struct remote *remote, const char *refname,
2353                           struct object_id *oid)
2354{
2355        char *dst;
2356
2357        dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2358        if (!dst)
2359                return -1; /* no tracking ref for refname at remote */
2360        if (read_ref(dst, oid))
2361                return -1; /* we know what the tracking ref is but we cannot read it */
2362        return 0;
2363}
2364
2365static void apply_cas(struct push_cas_option *cas,
2366                      struct remote *remote,
2367                      struct ref *ref)
2368{
2369        int i;
2370
2371        /* Find an explicit --<option>=<name>[:<value>] entry */
2372        for (i = 0; i < cas->nr; i++) {
2373                struct push_cas *entry = &cas->entry[i];
2374                if (!refname_match(entry->refname, ref->name))
2375                        continue;
2376                ref->expect_old_sha1 = 1;
2377                if (!entry->use_tracking)
2378                        oidcpy(&ref->old_oid_expect, &entry->expect);
2379                else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2380                        oidclr(&ref->old_oid_expect);
2381                return;
2382        }
2383
2384        /* Are we using "--<option>" to cover all? */
2385        if (!cas->use_tracking_for_rest)
2386                return;
2387
2388        ref->expect_old_sha1 = 1;
2389        if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2390                oidclr(&ref->old_oid_expect);
2391}
2392
2393void apply_push_cas(struct push_cas_option *cas,
2394                    struct remote *remote,
2395                    struct ref *remote_refs)
2396{
2397        struct ref *ref;
2398        for (ref = remote_refs; ref; ref = ref->next)
2399                apply_cas(cas, remote, ref);
2400}