remote.con commit push doc: document the DWYM behavior pushing to unqualified <dst> (2219c09)
   1#include "cache.h"
   2#include "config.h"
   3#include "remote.h"
   4#include "refs.h"
   5#include "refspec.h"
   6#include "object-store.h"
   7#include "commit.h"
   8#include "diff.h"
   9#include "revision.h"
  10#include "dir.h"
  11#include "tag.h"
  12#include "string-list.h"
  13#include "mergesort.h"
  14#include "argv-array.h"
  15#include "commit-reach.h"
  16#include "advice.h"
  17
  18enum map_direction { FROM_SRC, FROM_DST };
  19
  20struct counted_string {
  21        size_t len;
  22        const char *s;
  23};
  24struct rewrite {
  25        const char *base;
  26        size_t baselen;
  27        struct counted_string *instead_of;
  28        int instead_of_nr;
  29        int instead_of_alloc;
  30};
  31struct rewrites {
  32        struct rewrite **rewrite;
  33        int rewrite_alloc;
  34        int rewrite_nr;
  35};
  36
  37static struct remote **remotes;
  38static int remotes_alloc;
  39static int remotes_nr;
  40static struct hashmap remotes_hash;
  41
  42static struct branch **branches;
  43static int branches_alloc;
  44static int branches_nr;
  45
  46static struct branch *current_branch;
  47static const char *pushremote_name;
  48
  49static struct rewrites rewrites;
  50static struct rewrites rewrites_push;
  51
  52static int valid_remote(const struct remote *remote)
  53{
  54        return (!!remote->url) || (!!remote->foreign_vcs);
  55}
  56
  57static const char *alias_url(const char *url, struct rewrites *r)
  58{
  59        int i, j;
  60        struct counted_string *longest;
  61        int longest_i;
  62
  63        longest = NULL;
  64        longest_i = -1;
  65        for (i = 0; i < r->rewrite_nr; i++) {
  66                if (!r->rewrite[i])
  67                        continue;
  68                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  69                        if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  70                            (!longest ||
  71                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  72                                longest = &(r->rewrite[i]->instead_of[j]);
  73                                longest_i = i;
  74                        }
  75                }
  76        }
  77        if (!longest)
  78                return url;
  79
  80        return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  81}
  82
  83static void add_url(struct remote *remote, const char *url)
  84{
  85        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
  86        remote->url[remote->url_nr++] = url;
  87}
  88
  89static void add_pushurl(struct remote *remote, const char *pushurl)
  90{
  91        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
  92        remote->pushurl[remote->pushurl_nr++] = pushurl;
  93}
  94
  95static void add_pushurl_alias(struct remote *remote, const char *url)
  96{
  97        const char *pushurl = alias_url(url, &rewrites_push);
  98        if (pushurl != url)
  99                add_pushurl(remote, pushurl);
 100}
 101
 102static void add_url_alias(struct remote *remote, const char *url)
 103{
 104        add_url(remote, alias_url(url, &rewrites));
 105        add_pushurl_alias(remote, url);
 106}
 107
 108struct remotes_hash_key {
 109        const char *str;
 110        int len;
 111};
 112
 113static int remotes_hash_cmp(const void *unused_cmp_data,
 114                            const void *entry,
 115                            const void *entry_or_key,
 116                            const void *keydata)
 117{
 118        const struct remote *a = entry;
 119        const struct remote *b = entry_or_key;
 120        const struct remotes_hash_key *key = keydata;
 121
 122        if (key)
 123                return strncmp(a->name, key->str, key->len) || a->name[key->len];
 124        else
 125                return strcmp(a->name, b->name);
 126}
 127
 128static inline void init_remotes_hash(void)
 129{
 130        if (!remotes_hash.cmpfn)
 131                hashmap_init(&remotes_hash, remotes_hash_cmp, NULL, 0);
 132}
 133
 134static struct remote *make_remote(const char *name, int len)
 135{
 136        struct remote *ret, *replaced;
 137        struct remotes_hash_key lookup;
 138        struct hashmap_entry lookup_entry;
 139
 140        if (!len)
 141                len = strlen(name);
 142
 143        init_remotes_hash();
 144        lookup.str = name;
 145        lookup.len = len;
 146        hashmap_entry_init(&lookup_entry, memhash(name, len));
 147
 148        if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 149                return ret;
 150
 151        ret = xcalloc(1, sizeof(struct remote));
 152        ret->prune = -1;  /* unspecified */
 153        ret->prune_tags = -1;  /* unspecified */
 154        ret->name = xstrndup(name, len);
 155        refspec_init(&ret->push, REFSPEC_PUSH);
 156        refspec_init(&ret->fetch, REFSPEC_FETCH);
 157
 158        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 159        remotes[remotes_nr++] = ret;
 160
 161        hashmap_entry_init(ret, lookup_entry.hash);
 162        replaced = hashmap_put(&remotes_hash, ret);
 163        assert(replaced == NULL);  /* no previous entry overwritten */
 164        return ret;
 165}
 166
 167static void add_merge(struct branch *branch, const char *name)
 168{
 169        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 170                   branch->merge_alloc);
 171        branch->merge_name[branch->merge_nr++] = name;
 172}
 173
 174static struct branch *make_branch(const char *name, int len)
 175{
 176        struct branch *ret;
 177        int i;
 178
 179        for (i = 0; i < branches_nr; i++) {
 180                if (len ? (!strncmp(name, branches[i]->name, len) &&
 181                           !branches[i]->name[len]) :
 182                    !strcmp(name, branches[i]->name))
 183                        return branches[i];
 184        }
 185
 186        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 187        ret = xcalloc(1, sizeof(struct branch));
 188        branches[branches_nr++] = ret;
 189        if (len)
 190                ret->name = xstrndup(name, len);
 191        else
 192                ret->name = xstrdup(name);
 193        ret->refname = xstrfmt("refs/heads/%s", ret->name);
 194
 195        return ret;
 196}
 197
 198static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 199{
 200        struct rewrite *ret;
 201        int i;
 202
 203        for (i = 0; i < r->rewrite_nr; i++) {
 204                if (len
 205                    ? (len == r->rewrite[i]->baselen &&
 206                       !strncmp(base, r->rewrite[i]->base, len))
 207                    : !strcmp(base, r->rewrite[i]->base))
 208                        return r->rewrite[i];
 209        }
 210
 211        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 212        ret = xcalloc(1, sizeof(struct rewrite));
 213        r->rewrite[r->rewrite_nr++] = ret;
 214        if (len) {
 215                ret->base = xstrndup(base, len);
 216                ret->baselen = len;
 217        }
 218        else {
 219                ret->base = xstrdup(base);
 220                ret->baselen = strlen(base);
 221        }
 222        return ret;
 223}
 224
 225static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 226{
 227        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 228        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 229        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 230        rewrite->instead_of_nr++;
 231}
 232
 233static const char *skip_spaces(const char *s)
 234{
 235        while (isspace(*s))
 236                s++;
 237        return s;
 238}
 239
 240static void read_remotes_file(struct remote *remote)
 241{
 242        struct strbuf buf = STRBUF_INIT;
 243        FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");
 244
 245        if (!f)
 246                return;
 247        remote->configured_in_repo = 1;
 248        remote->origin = REMOTE_REMOTES;
 249        while (strbuf_getline(&buf, f) != EOF) {
 250                const char *v;
 251
 252                strbuf_rtrim(&buf);
 253
 254                if (skip_prefix(buf.buf, "URL:", &v))
 255                        add_url_alias(remote, xstrdup(skip_spaces(v)));
 256                else if (skip_prefix(buf.buf, "Push:", &v))
 257                        refspec_append(&remote->push, skip_spaces(v));
 258                else if (skip_prefix(buf.buf, "Pull:", &v))
 259                        refspec_append(&remote->fetch, skip_spaces(v));
 260        }
 261        strbuf_release(&buf);
 262        fclose(f);
 263}
 264
 265static void read_branches_file(struct remote *remote)
 266{
 267        char *frag;
 268        struct strbuf buf = STRBUF_INIT;
 269        FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");
 270
 271        if (!f)
 272                return;
 273
 274        strbuf_getline_lf(&buf, f);
 275        fclose(f);
 276        strbuf_trim(&buf);
 277        if (!buf.len) {
 278                strbuf_release(&buf);
 279                return;
 280        }
 281
 282        remote->configured_in_repo = 1;
 283        remote->origin = REMOTE_BRANCHES;
 284
 285        /*
 286         * The branches file would have URL and optionally
 287         * #branch specified.  The "master" (or specified) branch is
 288         * fetched and stored in the local branch matching the
 289         * remote name.
 290         */
 291        frag = strchr(buf.buf, '#');
 292        if (frag)
 293                *(frag++) = '\0';
 294        else
 295                frag = "master";
 296
 297        add_url_alias(remote, strbuf_detach(&buf, NULL));
 298        strbuf_addf(&buf, "refs/heads/%s:refs/heads/%s",
 299                    frag, remote->name);
 300        refspec_append(&remote->fetch, buf.buf);
 301
 302        /*
 303         * Cogito compatible push: push current HEAD to remote #branch
 304         * (master if missing)
 305         */
 306        strbuf_reset(&buf);
 307        strbuf_addf(&buf, "HEAD:refs/heads/%s", frag);
 308        refspec_append(&remote->push, buf.buf);
 309        remote->fetch_tags = 1; /* always auto-follow */
 310        strbuf_release(&buf);
 311}
 312
 313static int handle_config(const char *key, const char *value, void *cb)
 314{
 315        const char *name;
 316        int namelen;
 317        const char *subkey;
 318        struct remote *remote;
 319        struct branch *branch;
 320        if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 321                if (!name)
 322                        return 0;
 323                branch = make_branch(name, namelen);
 324                if (!strcmp(subkey, "remote")) {
 325                        return git_config_string(&branch->remote_name, key, value);
 326                } else if (!strcmp(subkey, "pushremote")) {
 327                        return git_config_string(&branch->pushremote_name, key, value);
 328                } else if (!strcmp(subkey, "merge")) {
 329                        if (!value)
 330                                return config_error_nonbool(key);
 331                        add_merge(branch, xstrdup(value));
 332                }
 333                return 0;
 334        }
 335        if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 336                struct rewrite *rewrite;
 337                if (!name)
 338                        return 0;
 339                if (!strcmp(subkey, "insteadof")) {
 340                        rewrite = make_rewrite(&rewrites, name, namelen);
 341                        if (!value)
 342                                return config_error_nonbool(key);
 343                        add_instead_of(rewrite, xstrdup(value));
 344                } else if (!strcmp(subkey, "pushinsteadof")) {
 345                        rewrite = make_rewrite(&rewrites_push, name, namelen);
 346                        if (!value)
 347                                return config_error_nonbool(key);
 348                        add_instead_of(rewrite, xstrdup(value));
 349                }
 350        }
 351
 352        if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 353                return 0;
 354
 355        /* Handle remote.* variables */
 356        if (!name && !strcmp(subkey, "pushdefault"))
 357                return git_config_string(&pushremote_name, key, value);
 358
 359        if (!name)
 360                return 0;
 361        /* Handle remote.<name>.* variables */
 362        if (*name == '/') {
 363                warning("Config remote shorthand cannot begin with '/': %s",
 364                        name);
 365                return 0;
 366        }
 367        remote = make_remote(name, namelen);
 368        remote->origin = REMOTE_CONFIG;
 369        if (current_config_scope() == CONFIG_SCOPE_REPO)
 370                remote->configured_in_repo = 1;
 371        if (!strcmp(subkey, "mirror"))
 372                remote->mirror = git_config_bool(key, value);
 373        else if (!strcmp(subkey, "skipdefaultupdate"))
 374                remote->skip_default_update = git_config_bool(key, value);
 375        else if (!strcmp(subkey, "skipfetchall"))
 376                remote->skip_default_update = git_config_bool(key, value);
 377        else if (!strcmp(subkey, "prune"))
 378                remote->prune = git_config_bool(key, value);
 379        else if (!strcmp(subkey, "prunetags"))
 380                remote->prune_tags = git_config_bool(key, value);
 381        else if (!strcmp(subkey, "url")) {
 382                const char *v;
 383                if (git_config_string(&v, key, value))
 384                        return -1;
 385                add_url(remote, v);
 386        } else if (!strcmp(subkey, "pushurl")) {
 387                const char *v;
 388                if (git_config_string(&v, key, value))
 389                        return -1;
 390                add_pushurl(remote, v);
 391        } else if (!strcmp(subkey, "push")) {
 392                const char *v;
 393                if (git_config_string(&v, key, value))
 394                        return -1;
 395                refspec_append(&remote->push, v);
 396                free((char *)v);
 397        } else if (!strcmp(subkey, "fetch")) {
 398                const char *v;
 399                if (git_config_string(&v, key, value))
 400                        return -1;
 401                refspec_append(&remote->fetch, v);
 402                free((char *)v);
 403        } else if (!strcmp(subkey, "receivepack")) {
 404                const char *v;
 405                if (git_config_string(&v, key, value))
 406                        return -1;
 407                if (!remote->receivepack)
 408                        remote->receivepack = v;
 409                else
 410                        error(_("more than one receivepack given, using the first"));
 411        } else if (!strcmp(subkey, "uploadpack")) {
 412                const char *v;
 413                if (git_config_string(&v, key, value))
 414                        return -1;
 415                if (!remote->uploadpack)
 416                        remote->uploadpack = v;
 417                else
 418                        error(_("more than one uploadpack given, using the first"));
 419        } else if (!strcmp(subkey, "tagopt")) {
 420                if (!strcmp(value, "--no-tags"))
 421                        remote->fetch_tags = -1;
 422                else if (!strcmp(value, "--tags"))
 423                        remote->fetch_tags = 2;
 424        } else if (!strcmp(subkey, "proxy")) {
 425                return git_config_string((const char **)&remote->http_proxy,
 426                                         key, value);
 427        } else if (!strcmp(subkey, "proxyauthmethod")) {
 428                return git_config_string((const char **)&remote->http_proxy_authmethod,
 429                                         key, value);
 430        } else if (!strcmp(subkey, "vcs")) {
 431                return git_config_string(&remote->foreign_vcs, key, value);
 432        }
 433        return 0;
 434}
 435
 436static void alias_all_urls(void)
 437{
 438        int i, j;
 439        for (i = 0; i < remotes_nr; i++) {
 440                int add_pushurl_aliases;
 441                if (!remotes[i])
 442                        continue;
 443                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 444                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 445                }
 446                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 447                for (j = 0; j < remotes[i]->url_nr; j++) {
 448                        if (add_pushurl_aliases)
 449                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 450                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 451                }
 452        }
 453}
 454
 455static void read_config(void)
 456{
 457        static int loaded;
 458        int flag;
 459
 460        if (loaded)
 461                return;
 462        loaded = 1;
 463
 464        current_branch = NULL;
 465        if (startup_info->have_repository) {
 466                const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
 467                if (head_ref && (flag & REF_ISSYMREF) &&
 468                    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 469                        current_branch = make_branch(head_ref, 0);
 470                }
 471        }
 472        git_config(handle_config, NULL);
 473        alias_all_urls();
 474}
 475
 476static int valid_remote_nick(const char *name)
 477{
 478        if (!name[0] || is_dot_or_dotdot(name))
 479                return 0;
 480
 481        /* remote nicknames cannot contain slashes */
 482        while (*name)
 483                if (is_dir_sep(*name++))
 484                        return 0;
 485        return 1;
 486}
 487
 488const char *remote_for_branch(struct branch *branch, int *explicit)
 489{
 490        if (branch && branch->remote_name) {
 491                if (explicit)
 492                        *explicit = 1;
 493                return branch->remote_name;
 494        }
 495        if (explicit)
 496                *explicit = 0;
 497        return "origin";
 498}
 499
 500const char *pushremote_for_branch(struct branch *branch, int *explicit)
 501{
 502        if (branch && branch->pushremote_name) {
 503                if (explicit)
 504                        *explicit = 1;
 505                return branch->pushremote_name;
 506        }
 507        if (pushremote_name) {
 508                if (explicit)
 509                        *explicit = 1;
 510                return pushremote_name;
 511        }
 512        return remote_for_branch(branch, explicit);
 513}
 514
 515const char *remote_ref_for_branch(struct branch *branch, int for_push,
 516                                  int *explicit)
 517{
 518        if (branch) {
 519                if (!for_push) {
 520                        if (branch->merge_nr) {
 521                                if (explicit)
 522                                        *explicit = 1;
 523                                return branch->merge_name[0];
 524                        }
 525                } else {
 526                        const char *dst, *remote_name =
 527                                pushremote_for_branch(branch, NULL);
 528                        struct remote *remote = remote_get(remote_name);
 529
 530                        if (remote && remote->push.nr &&
 531                            (dst = apply_refspecs(&remote->push,
 532                                                  branch->refname))) {
 533                                if (explicit)
 534                                        *explicit = 1;
 535                                return dst;
 536                        }
 537                }
 538        }
 539        if (explicit)
 540                *explicit = 0;
 541        return "";
 542}
 543
 544static struct remote *remote_get_1(const char *name,
 545                                   const char *(*get_default)(struct branch *, int *))
 546{
 547        struct remote *ret;
 548        int name_given = 0;
 549
 550        read_config();
 551
 552        if (name)
 553                name_given = 1;
 554        else
 555                name = get_default(current_branch, &name_given);
 556
 557        ret = make_remote(name, 0);
 558        if (valid_remote_nick(name) && have_git_dir()) {
 559                if (!valid_remote(ret))
 560                        read_remotes_file(ret);
 561                if (!valid_remote(ret))
 562                        read_branches_file(ret);
 563        }
 564        if (name_given && !valid_remote(ret))
 565                add_url_alias(ret, name);
 566        if (!valid_remote(ret))
 567                return NULL;
 568        return ret;
 569}
 570
 571struct remote *remote_get(const char *name)
 572{
 573        return remote_get_1(name, remote_for_branch);
 574}
 575
 576struct remote *pushremote_get(const char *name)
 577{
 578        return remote_get_1(name, pushremote_for_branch);
 579}
 580
 581int remote_is_configured(struct remote *remote, int in_repo)
 582{
 583        if (!remote)
 584                return 0;
 585        if (in_repo)
 586                return remote->configured_in_repo;
 587        return !!remote->origin;
 588}
 589
 590int for_each_remote(each_remote_fn fn, void *priv)
 591{
 592        int i, result = 0;
 593        read_config();
 594        for (i = 0; i < remotes_nr && !result; i++) {
 595                struct remote *r = remotes[i];
 596                if (!r)
 597                        continue;
 598                result = fn(r, priv);
 599        }
 600        return result;
 601}
 602
 603static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 604{
 605        if (strcmp(ref1->name, ref2->name)) {
 606                if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 607                    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 608                        die(_("Cannot fetch both %s and %s to %s"),
 609                            ref1->name, ref2->name, ref2->peer_ref->name);
 610                } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 611                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 612                        warning(_("%s usually tracks %s, not %s"),
 613                                ref2->peer_ref->name, ref2->name, ref1->name);
 614                } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 615                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 616                        die(_("%s tracks both %s and %s"),
 617                            ref2->peer_ref->name, ref1->name, ref2->name);
 618                } else {
 619                        /*
 620                         * This last possibility doesn't occur because
 621                         * FETCH_HEAD_IGNORE entries always appear at
 622                         * the end of the list.
 623                         */
 624                        die(_("Internal error"));
 625                }
 626        }
 627        free(ref2->peer_ref);
 628        free(ref2);
 629}
 630
 631struct ref *ref_remove_duplicates(struct ref *ref_map)
 632{
 633        struct string_list refs = STRING_LIST_INIT_NODUP;
 634        struct ref *retval = NULL;
 635        struct ref **p = &retval;
 636
 637        while (ref_map) {
 638                struct ref *ref = ref_map;
 639
 640                ref_map = ref_map->next;
 641                ref->next = NULL;
 642
 643                if (!ref->peer_ref) {
 644                        *p = ref;
 645                        p = &ref->next;
 646                } else {
 647                        struct string_list_item *item =
 648                                string_list_insert(&refs, ref->peer_ref->name);
 649
 650                        if (item->util) {
 651                                /* Entry already existed */
 652                                handle_duplicate((struct ref *)item->util, ref);
 653                        } else {
 654                                *p = ref;
 655                                p = &ref->next;
 656                                item->util = ref;
 657                        }
 658                }
 659        }
 660
 661        string_list_clear(&refs, 0);
 662        return retval;
 663}
 664
 665int remote_has_url(struct remote *remote, const char *url)
 666{
 667        int i;
 668        for (i = 0; i < remote->url_nr; i++) {
 669                if (!strcmp(remote->url[i], url))
 670                        return 1;
 671        }
 672        return 0;
 673}
 674
 675static int match_name_with_pattern(const char *key, const char *name,
 676                                   const char *value, char **result)
 677{
 678        const char *kstar = strchr(key, '*');
 679        size_t klen;
 680        size_t ksuffixlen;
 681        size_t namelen;
 682        int ret;
 683        if (!kstar)
 684                die("Key '%s' of pattern had no '*'", key);
 685        klen = kstar - key;
 686        ksuffixlen = strlen(kstar + 1);
 687        namelen = strlen(name);
 688        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 689                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 690        if (ret && value) {
 691                struct strbuf sb = STRBUF_INIT;
 692                const char *vstar = strchr(value, '*');
 693                if (!vstar)
 694                        die("Value '%s' of pattern has no '*'", value);
 695                strbuf_add(&sb, value, vstar - value);
 696                strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 697                strbuf_addstr(&sb, vstar + 1);
 698                *result = strbuf_detach(&sb, NULL);
 699        }
 700        return ret;
 701}
 702
 703static void query_refspecs_multiple(struct refspec *rs,
 704                                    struct refspec_item *query,
 705                                    struct string_list *results)
 706{
 707        int i;
 708        int find_src = !query->src;
 709
 710        if (find_src && !query->dst)
 711                error(_("query_refspecs_multiple: need either src or dst"));
 712
 713        for (i = 0; i < rs->nr; i++) {
 714                struct refspec_item *refspec = &rs->items[i];
 715                const char *key = find_src ? refspec->dst : refspec->src;
 716                const char *value = find_src ? refspec->src : refspec->dst;
 717                const char *needle = find_src ? query->dst : query->src;
 718                char **result = find_src ? &query->src : &query->dst;
 719
 720                if (!refspec->dst)
 721                        continue;
 722                if (refspec->pattern) {
 723                        if (match_name_with_pattern(key, needle, value, result))
 724                                string_list_append_nodup(results, *result);
 725                } else if (!strcmp(needle, key)) {
 726                        string_list_append(results, value);
 727                }
 728        }
 729}
 730
 731int query_refspecs(struct refspec *rs, struct refspec_item *query)
 732{
 733        int i;
 734        int find_src = !query->src;
 735        const char *needle = find_src ? query->dst : query->src;
 736        char **result = find_src ? &query->src : &query->dst;
 737
 738        if (find_src && !query->dst)
 739                return error(_("query_refspecs: need either src or dst"));
 740
 741        for (i = 0; i < rs->nr; i++) {
 742                struct refspec_item *refspec = &rs->items[i];
 743                const char *key = find_src ? refspec->dst : refspec->src;
 744                const char *value = find_src ? refspec->src : refspec->dst;
 745
 746                if (!refspec->dst)
 747                        continue;
 748                if (refspec->pattern) {
 749                        if (match_name_with_pattern(key, needle, value, result)) {
 750                                query->force = refspec->force;
 751                                return 0;
 752                        }
 753                } else if (!strcmp(needle, key)) {
 754                        *result = xstrdup(value);
 755                        query->force = refspec->force;
 756                        return 0;
 757                }
 758        }
 759        return -1;
 760}
 761
 762char *apply_refspecs(struct refspec *rs, const char *name)
 763{
 764        struct refspec_item query;
 765
 766        memset(&query, 0, sizeof(struct refspec_item));
 767        query.src = (char *)name;
 768
 769        if (query_refspecs(rs, &query))
 770                return NULL;
 771
 772        return query.dst;
 773}
 774
 775int remote_find_tracking(struct remote *remote, struct refspec_item *refspec)
 776{
 777        return query_refspecs(&remote->fetch, refspec);
 778}
 779
 780static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 781                const char *name)
 782{
 783        size_t len = strlen(name);
 784        struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 785        memcpy(ref->name, prefix, prefixlen);
 786        memcpy(ref->name + prefixlen, name, len);
 787        return ref;
 788}
 789
 790struct ref *alloc_ref(const char *name)
 791{
 792        return alloc_ref_with_prefix("", 0, name);
 793}
 794
 795struct ref *copy_ref(const struct ref *ref)
 796{
 797        struct ref *cpy;
 798        size_t len;
 799        if (!ref)
 800                return NULL;
 801        len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 802        cpy = xmalloc(len);
 803        memcpy(cpy, ref, len);
 804        cpy->next = NULL;
 805        cpy->symref = xstrdup_or_null(ref->symref);
 806        cpy->remote_status = xstrdup_or_null(ref->remote_status);
 807        cpy->peer_ref = copy_ref(ref->peer_ref);
 808        return cpy;
 809}
 810
 811struct ref *copy_ref_list(const struct ref *ref)
 812{
 813        struct ref *ret = NULL;
 814        struct ref **tail = &ret;
 815        while (ref) {
 816                *tail = copy_ref(ref);
 817                ref = ref->next;
 818                tail = &((*tail)->next);
 819        }
 820        return ret;
 821}
 822
 823static void free_ref(struct ref *ref)
 824{
 825        if (!ref)
 826                return;
 827        free_ref(ref->peer_ref);
 828        free(ref->remote_status);
 829        free(ref->symref);
 830        free(ref);
 831}
 832
 833void free_refs(struct ref *ref)
 834{
 835        struct ref *next;
 836        while (ref) {
 837                next = ref->next;
 838                free_ref(ref);
 839                ref = next;
 840        }
 841}
 842
 843int ref_compare_name(const void *va, const void *vb)
 844{
 845        const struct ref *a = va, *b = vb;
 846        return strcmp(a->name, b->name);
 847}
 848
 849static void *ref_list_get_next(const void *a)
 850{
 851        return ((const struct ref *)a)->next;
 852}
 853
 854static void ref_list_set_next(void *a, void *next)
 855{
 856        ((struct ref *)a)->next = next;
 857}
 858
 859void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 860{
 861        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 862}
 863
 864int count_refspec_match(const char *pattern,
 865                        struct ref *refs,
 866                        struct ref **matched_ref)
 867{
 868        int patlen = strlen(pattern);
 869        struct ref *matched_weak = NULL;
 870        struct ref *matched = NULL;
 871        int weak_match = 0;
 872        int match = 0;
 873
 874        for (weak_match = match = 0; refs; refs = refs->next) {
 875                char *name = refs->name;
 876                int namelen = strlen(name);
 877
 878                if (!refname_match(pattern, name))
 879                        continue;
 880
 881                /* A match is "weak" if it is with refs outside
 882                 * heads or tags, and did not specify the pattern
 883                 * in full (e.g. "refs/remotes/origin/master") or at
 884                 * least from the toplevel (e.g. "remotes/origin/master");
 885                 * otherwise "git push $URL master" would result in
 886                 * ambiguity between remotes/origin/master and heads/master
 887                 * at the remote site.
 888                 */
 889                if (namelen != patlen &&
 890                    patlen != namelen - 5 &&
 891                    !starts_with(name, "refs/heads/") &&
 892                    !starts_with(name, "refs/tags/")) {
 893                        /* We want to catch the case where only weak
 894                         * matches are found and there are multiple
 895                         * matches, and where more than one strong
 896                         * matches are found, as ambiguous.  One
 897                         * strong match with zero or more weak matches
 898                         * are acceptable as a unique match.
 899                         */
 900                        matched_weak = refs;
 901                        weak_match++;
 902                }
 903                else {
 904                        matched = refs;
 905                        match++;
 906                }
 907        }
 908        if (!matched) {
 909                if (matched_ref)
 910                        *matched_ref = matched_weak;
 911                return weak_match;
 912        }
 913        else {
 914                if (matched_ref)
 915                        *matched_ref = matched;
 916                return match;
 917        }
 918}
 919
 920static void tail_link_ref(struct ref *ref, struct ref ***tail)
 921{
 922        **tail = ref;
 923        while (ref->next)
 924                ref = ref->next;
 925        *tail = &ref->next;
 926}
 927
 928static struct ref *alloc_delete_ref(void)
 929{
 930        struct ref *ref = alloc_ref("(delete)");
 931        oidclr(&ref->new_oid);
 932        return ref;
 933}
 934
 935static int try_explicit_object_name(const char *name,
 936                                    struct ref **match)
 937{
 938        struct object_id oid;
 939
 940        if (!*name) {
 941                if (match)
 942                        *match = alloc_delete_ref();
 943                return 0;
 944        }
 945
 946        if (get_oid(name, &oid))
 947                return -1;
 948
 949        if (match) {
 950                *match = alloc_ref(name);
 951                oidcpy(&(*match)->new_oid, &oid);
 952        }
 953        return 0;
 954}
 955
 956static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 957{
 958        struct ref *ret = alloc_ref(name);
 959        tail_link_ref(ret, tail);
 960        return ret;
 961}
 962
 963static char *guess_ref(const char *name, struct ref *peer)
 964{
 965        struct strbuf buf = STRBUF_INIT;
 966
 967        const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
 968                                           NULL, NULL);
 969        if (!r)
 970                return NULL;
 971
 972        if (starts_with(r, "refs/heads/")) {
 973                strbuf_addstr(&buf, "refs/heads/");
 974        } else if (starts_with(r, "refs/tags/")) {
 975                strbuf_addstr(&buf, "refs/tags/");
 976        } else {
 977                return NULL;
 978        }
 979
 980        strbuf_addstr(&buf, name);
 981        return strbuf_detach(&buf, NULL);
 982}
 983
 984static int match_explicit_lhs(struct ref *src,
 985                              struct refspec_item *rs,
 986                              struct ref **match,
 987                              int *allocated_match)
 988{
 989        switch (count_refspec_match(rs->src, src, match)) {
 990        case 1:
 991                if (allocated_match)
 992                        *allocated_match = 0;
 993                return 0;
 994        case 0:
 995                /* The source could be in the get_sha1() format
 996                 * not a reference name.  :refs/other is a
 997                 * way to delete 'other' ref at the remote end.
 998                 */
 999                if (try_explicit_object_name(rs->src, match) < 0)
1000                        return error(_("src refspec %s does not match any."), rs->src);
1001                if (allocated_match)
1002                        *allocated_match = 1;
1003                return 0;
1004        default:
1005                return error(_("src refspec %s matches more than one."), rs->src);
1006        }
1007}
1008
1009static void show_push_unqualified_ref_name_error(const char *dst_value,
1010                                                 const char *matched_src_name)
1011{
1012        struct object_id oid;
1013        enum object_type type;
1014
1015        /*
1016         * TRANSLATORS: "matches '%s'%" is the <dst> part of "git push
1017         * <remote> <src>:<dst>" push, and "being pushed ('%s')" is
1018         * the <src>.
1019         */
1020        error(_("The destination you provided is not a full refname (i.e.,\n"
1021                "starting with \"refs/\"). We tried to guess what you meant by:\n"
1022                "\n"
1023                "- Looking for a ref that matches '%s' on the remote side.\n"
1024                "- Checking if the <src> being pushed ('%s')\n"
1025                "  is a ref in \"refs/{heads,tags}/\". If so we add a corresponding\n"
1026                "  refs/{heads,tags}/ prefix on the remote side.\n"
1027                "\n"
1028                "Neither worked, so we gave up. You must fully qualify the ref."),
1029              dst_value, matched_src_name);
1030
1031        if (!advice_push_unqualified_ref_name)
1032                return;
1033
1034        if (get_oid(matched_src_name, &oid))
1035                BUG("'%s' is not a valid object, "
1036                    "match_explicit_lhs() should catch this!",
1037                    matched_src_name);
1038        type = oid_object_info(the_repository, &oid, NULL);
1039        if (type == OBJ_COMMIT) {
1040                advise(_("The <src> part of the refspec is a commit object.\n"
1041                         "Did you mean to create a new branch by pushing to\n"
1042                         "'%s:refs/heads/%s'?"),
1043                       matched_src_name, dst_value);
1044        } else if (type == OBJ_TAG) {
1045                advise(_("The <src> part of the refspec is a tag object.\n"
1046                         "Did you mean to create a new tag by pushing to\n"
1047                         "'%s:refs/tags/%s'?"),
1048                       matched_src_name, dst_value);
1049        } else if (type == OBJ_TREE) {
1050                advise(_("The <src> part of the refspec is a tree object.\n"
1051                         "Did you mean to tag a new tree by pushing to\n"
1052                         "'%s:refs/tags/%s'?"),
1053                       matched_src_name, dst_value);
1054        } else if (type == OBJ_BLOB) {
1055                advise(_("The <src> part of the refspec is a blob object.\n"
1056                         "Did you mean to tag a new blob by pushing to\n"
1057                         "'%s:refs/tags/%s'?"),
1058                       matched_src_name, dst_value);
1059        } else {
1060                BUG("'%s' should be commit/tag/tree/blob, is '%d'",
1061                    matched_src_name, type);
1062        }
1063}
1064
1065static int match_explicit(struct ref *src, struct ref *dst,
1066                          struct ref ***dst_tail,
1067                          struct refspec_item *rs)
1068{
1069        struct ref *matched_src, *matched_dst;
1070        int allocated_src;
1071
1072        const char *dst_value = rs->dst;
1073        char *dst_guess;
1074
1075        if (rs->pattern || rs->matching)
1076                return 0;
1077
1078        matched_src = matched_dst = NULL;
1079        if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1080                return -1;
1081
1082        if (!dst_value) {
1083                int flag;
1084
1085                dst_value = resolve_ref_unsafe(matched_src->name,
1086                                               RESOLVE_REF_READING,
1087                                               NULL, &flag);
1088                if (!dst_value ||
1089                    ((flag & REF_ISSYMREF) &&
1090                     !starts_with(dst_value, "refs/heads/")))
1091                        die("%s cannot be resolved to branch.",
1092                            matched_src->name);
1093        }
1094
1095        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1096        case 1:
1097                break;
1098        case 0:
1099                if (starts_with(dst_value, "refs/")) {
1100                        matched_dst = make_linked_ref(dst_value, dst_tail);
1101
1102                } else if (is_null_oid(&matched_src->new_oid)) {
1103                        error(_("unable to delete '%s': remote ref does not exist"),
1104                              dst_value);
1105                } else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1106                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1107                        free(dst_guess);
1108                } else {
1109                        show_push_unqualified_ref_name_error(dst_value,
1110                                                             matched_src->name);
1111                }
1112                break;
1113        default:
1114                matched_dst = NULL;
1115                error(_("dst refspec %s matches more than one."),
1116                      dst_value);
1117                break;
1118        }
1119        if (!matched_dst)
1120                return -1;
1121        if (matched_dst->peer_ref)
1122                return error(_("dst ref %s receives from more than one src."),
1123                             matched_dst->name);
1124        else {
1125                matched_dst->peer_ref = allocated_src ?
1126                                        matched_src :
1127                                        copy_ref(matched_src);
1128                matched_dst->force = rs->force;
1129        }
1130        return 0;
1131}
1132
1133static int match_explicit_refs(struct ref *src, struct ref *dst,
1134                               struct ref ***dst_tail, struct refspec *rs)
1135{
1136        int i, errs;
1137        for (i = errs = 0; i < rs->nr; i++)
1138                errs += match_explicit(src, dst, dst_tail, &rs->items[i]);
1139        return errs;
1140}
1141
1142static char *get_ref_match(const struct refspec *rs, const struct ref *ref,
1143                           int send_mirror, int direction,
1144                           const struct refspec_item **ret_pat)
1145{
1146        const struct refspec_item *pat;
1147        char *name;
1148        int i;
1149        int matching_refs = -1;
1150        for (i = 0; i < rs->nr; i++) {
1151                const struct refspec_item *item = &rs->items[i];
1152                if (item->matching &&
1153                    (matching_refs == -1 || item->force)) {
1154                        matching_refs = i;
1155                        continue;
1156                }
1157
1158                if (item->pattern) {
1159                        const char *dst_side = item->dst ? item->dst : item->src;
1160                        int match;
1161                        if (direction == FROM_SRC)
1162                                match = match_name_with_pattern(item->src, ref->name, dst_side, &name);
1163                        else
1164                                match = match_name_with_pattern(dst_side, ref->name, item->src, &name);
1165                        if (match) {
1166                                matching_refs = i;
1167                                break;
1168                        }
1169                }
1170        }
1171        if (matching_refs == -1)
1172                return NULL;
1173
1174        pat = &rs->items[matching_refs];
1175        if (pat->matching) {
1176                /*
1177                 * "matching refs"; traditionally we pushed everything
1178                 * including refs outside refs/heads/ hierarchy, but
1179                 * that does not make much sense these days.
1180                 */
1181                if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1182                        return NULL;
1183                name = xstrdup(ref->name);
1184        }
1185        if (ret_pat)
1186                *ret_pat = pat;
1187        return name;
1188}
1189
1190static struct ref **tail_ref(struct ref **head)
1191{
1192        struct ref **tail = head;
1193        while (*tail)
1194                tail = &((*tail)->next);
1195        return tail;
1196}
1197
1198struct tips {
1199        struct commit **tip;
1200        int nr, alloc;
1201};
1202
1203static void add_to_tips(struct tips *tips, const struct object_id *oid)
1204{
1205        struct commit *commit;
1206
1207        if (is_null_oid(oid))
1208                return;
1209        commit = lookup_commit_reference_gently(the_repository, oid, 1);
1210        if (!commit || (commit->object.flags & TMP_MARK))
1211                return;
1212        commit->object.flags |= TMP_MARK;
1213        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1214        tips->tip[tips->nr++] = commit;
1215}
1216
1217static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1218{
1219        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1220        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1221        struct string_list_item *item;
1222        struct ref *ref;
1223        struct tips sent_tips;
1224
1225        /*
1226         * Collect everything we know they would have at the end of
1227         * this push, and collect all tags they have.
1228         */
1229        memset(&sent_tips, 0, sizeof(sent_tips));
1230        for (ref = *dst; ref; ref = ref->next) {
1231                if (ref->peer_ref &&
1232                    !is_null_oid(&ref->peer_ref->new_oid))
1233                        add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1234                else
1235                        add_to_tips(&sent_tips, &ref->old_oid);
1236                if (starts_with(ref->name, "refs/tags/"))
1237                        string_list_append(&dst_tag, ref->name);
1238        }
1239        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1240
1241        string_list_sort(&dst_tag);
1242
1243        /* Collect tags they do not have. */
1244        for (ref = src; ref; ref = ref->next) {
1245                if (!starts_with(ref->name, "refs/tags/"))
1246                        continue; /* not a tag */
1247                if (string_list_has_string(&dst_tag, ref->name))
1248                        continue; /* they already have it */
1249                if (oid_object_info(the_repository, &ref->new_oid, NULL) != OBJ_TAG)
1250                        continue; /* be conservative */
1251                item = string_list_append(&src_tag, ref->name);
1252                item->util = ref;
1253        }
1254        string_list_clear(&dst_tag, 0);
1255
1256        /*
1257         * At this point, src_tag lists tags that are missing from
1258         * dst, and sent_tips lists the tips we are pushing or those
1259         * that we know they already have. An element in the src_tag
1260         * that is an ancestor of any of the sent_tips needs to be
1261         * sent to the other side.
1262         */
1263        if (sent_tips.nr) {
1264                const int reachable_flag = 1;
1265                struct commit_list *found_commits;
1266                struct commit **src_commits;
1267                int nr_src_commits = 0, alloc_src_commits = 16;
1268                ALLOC_ARRAY(src_commits, alloc_src_commits);
1269
1270                for_each_string_list_item(item, &src_tag) {
1271                        struct ref *ref = item->util;
1272                        struct commit *commit;
1273
1274                        if (is_null_oid(&ref->new_oid))
1275                                continue;
1276                        commit = lookup_commit_reference_gently(the_repository,
1277                                                                &ref->new_oid,
1278                                                                1);
1279                        if (!commit)
1280                                /* not pushing a commit, which is not an error */
1281                                continue;
1282
1283                        ALLOC_GROW(src_commits, nr_src_commits + 1, alloc_src_commits);
1284                        src_commits[nr_src_commits++] = commit;
1285                }
1286
1287                found_commits = get_reachable_subset(sent_tips.tip, sent_tips.nr,
1288                                                     src_commits, nr_src_commits,
1289                                                     reachable_flag);
1290
1291                for_each_string_list_item(item, &src_tag) {
1292                        struct ref *dst_ref;
1293                        struct ref *ref = item->util;
1294                        struct commit *commit;
1295
1296                        if (is_null_oid(&ref->new_oid))
1297                                continue;
1298                        commit = lookup_commit_reference_gently(the_repository,
1299                                                                &ref->new_oid,
1300                                                                1);
1301                        if (!commit)
1302                                /* not pushing a commit, which is not an error */
1303                                continue;
1304
1305                        /*
1306                         * Is this tag, which they do not have, reachable from
1307                         * any of the commits we are sending?
1308                         */
1309                        if (!(commit->object.flags & reachable_flag))
1310                                continue;
1311
1312                        /* Add it in */
1313                        dst_ref = make_linked_ref(ref->name, dst_tail);
1314                        oidcpy(&dst_ref->new_oid, &ref->new_oid);
1315                        dst_ref->peer_ref = copy_ref(ref);
1316                }
1317
1318                clear_commit_marks_many(nr_src_commits, src_commits, reachable_flag);
1319                free(src_commits);
1320                free_commit_list(found_commits);
1321        }
1322
1323        string_list_clear(&src_tag, 0);
1324        free(sent_tips.tip);
1325}
1326
1327struct ref *find_ref_by_name(const struct ref *list, const char *name)
1328{
1329        for ( ; list; list = list->next)
1330                if (!strcmp(list->name, name))
1331                        return (struct ref *)list;
1332        return NULL;
1333}
1334
1335static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1336{
1337        for ( ; ref; ref = ref->next)
1338                string_list_append_nodup(ref_index, ref->name)->util = ref;
1339
1340        string_list_sort(ref_index);
1341}
1342
1343/*
1344 * Given only the set of local refs, sanity-check the set of push
1345 * refspecs. We can't catch all errors that match_push_refs would,
1346 * but we can catch some errors early before even talking to the
1347 * remote side.
1348 */
1349int check_push_refs(struct ref *src, struct refspec *rs)
1350{
1351        int ret = 0;
1352        int i;
1353
1354        for (i = 0; i < rs->nr; i++) {
1355                struct refspec_item *item = &rs->items[i];
1356
1357                if (item->pattern || item->matching)
1358                        continue;
1359
1360                ret |= match_explicit_lhs(src, item, NULL, NULL);
1361        }
1362
1363        return ret;
1364}
1365
1366/*
1367 * Given the set of refs the local repository has, the set of refs the
1368 * remote repository has, and the refspec used for push, determine
1369 * what remote refs we will update and with what value by setting
1370 * peer_ref (which object is being pushed) and force (if the push is
1371 * forced) in elements of "dst". The function may add new elements to
1372 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1373 */
1374int match_push_refs(struct ref *src, struct ref **dst,
1375                    struct refspec *rs, int flags)
1376{
1377        int send_all = flags & MATCH_REFS_ALL;
1378        int send_mirror = flags & MATCH_REFS_MIRROR;
1379        int send_prune = flags & MATCH_REFS_PRUNE;
1380        int errs;
1381        struct ref *ref, **dst_tail = tail_ref(dst);
1382        struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1383
1384        /* If no refspec is provided, use the default ":" */
1385        if (!rs->nr)
1386                refspec_append(rs, ":");
1387
1388        errs = match_explicit_refs(src, *dst, &dst_tail, rs);
1389
1390        /* pick the remainder */
1391        for (ref = src; ref; ref = ref->next) {
1392                struct string_list_item *dst_item;
1393                struct ref *dst_peer;
1394                const struct refspec_item *pat = NULL;
1395                char *dst_name;
1396
1397                dst_name = get_ref_match(rs, ref, send_mirror, FROM_SRC, &pat);
1398                if (!dst_name)
1399                        continue;
1400
1401                if (!dst_ref_index.nr)
1402                        prepare_ref_index(&dst_ref_index, *dst);
1403
1404                dst_item = string_list_lookup(&dst_ref_index, dst_name);
1405                dst_peer = dst_item ? dst_item->util : NULL;
1406                if (dst_peer) {
1407                        if (dst_peer->peer_ref)
1408                                /* We're already sending something to this ref. */
1409                                goto free_name;
1410                } else {
1411                        if (pat->matching && !(send_all || send_mirror))
1412                                /*
1413                                 * Remote doesn't have it, and we have no
1414                                 * explicit pattern, and we don't have
1415                                 * --all or --mirror.
1416                                 */
1417                                goto free_name;
1418
1419                        /* Create a new one and link it */
1420                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1421                        oidcpy(&dst_peer->new_oid, &ref->new_oid);
1422                        string_list_insert(&dst_ref_index,
1423                                dst_peer->name)->util = dst_peer;
1424                }
1425                dst_peer->peer_ref = copy_ref(ref);
1426                dst_peer->force = pat->force;
1427        free_name:
1428                free(dst_name);
1429        }
1430
1431        string_list_clear(&dst_ref_index, 0);
1432
1433        if (flags & MATCH_REFS_FOLLOW_TAGS)
1434                add_missing_tags(src, dst, &dst_tail);
1435
1436        if (send_prune) {
1437                struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1438                /* check for missing refs on the remote */
1439                for (ref = *dst; ref; ref = ref->next) {
1440                        char *src_name;
1441
1442                        if (ref->peer_ref)
1443                                /* We're already sending something to this ref. */
1444                                continue;
1445
1446                        src_name = get_ref_match(rs, ref, send_mirror, FROM_DST, NULL);
1447                        if (src_name) {
1448                                if (!src_ref_index.nr)
1449                                        prepare_ref_index(&src_ref_index, src);
1450                                if (!string_list_has_string(&src_ref_index,
1451                                            src_name))
1452                                        ref->peer_ref = alloc_delete_ref();
1453                                free(src_name);
1454                        }
1455                }
1456                string_list_clear(&src_ref_index, 0);
1457        }
1458
1459        if (errs)
1460                return -1;
1461        return 0;
1462}
1463
1464void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1465                             int force_update)
1466{
1467        struct ref *ref;
1468
1469        for (ref = remote_refs; ref; ref = ref->next) {
1470                int force_ref_update = ref->force || force_update;
1471                int reject_reason = 0;
1472
1473                if (ref->peer_ref)
1474                        oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1475                else if (!send_mirror)
1476                        continue;
1477
1478                ref->deletion = is_null_oid(&ref->new_oid);
1479                if (!ref->deletion &&
1480                        oideq(&ref->old_oid, &ref->new_oid)) {
1481                        ref->status = REF_STATUS_UPTODATE;
1482                        continue;
1483                }
1484
1485                /*
1486                 * If the remote ref has moved and is now different
1487                 * from what we expect, reject any push.
1488                 *
1489                 * It also is an error if the user told us to check
1490                 * with the remote-tracking branch to find the value
1491                 * to expect, but we did not have such a tracking
1492                 * branch.
1493                 */
1494                if (ref->expect_old_sha1) {
1495                        if (!oideq(&ref->old_oid, &ref->old_oid_expect))
1496                                reject_reason = REF_STATUS_REJECT_STALE;
1497                        else
1498                                /* If the ref isn't stale then force the update. */
1499                                force_ref_update = 1;
1500                }
1501
1502                /*
1503                 * If the update isn't already rejected then check
1504                 * the usual "must fast-forward" rules.
1505                 *
1506                 * Decide whether an individual refspec A:B can be
1507                 * pushed.  The push will succeed if any of the
1508                 * following are true:
1509                 *
1510                 * (1) the remote reference B does not exist
1511                 *
1512                 * (2) the remote reference B is being removed (i.e.,
1513                 *     pushing :B where no source is specified)
1514                 *
1515                 * (3) the destination is not under refs/tags/, and
1516                 *     if the old and new value is a commit, the new
1517                 *     is a descendant of the old.
1518                 *
1519                 * (4) it is forced using the +A:B notation, or by
1520                 *     passing the --force argument
1521                 */
1522
1523                if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1524                        if (starts_with(ref->name, "refs/tags/"))
1525                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1526                        else if (!has_object_file(&ref->old_oid))
1527                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1528                        else if (!lookup_commit_reference_gently(the_repository, &ref->old_oid, 1) ||
1529                                 !lookup_commit_reference_gently(the_repository, &ref->new_oid, 1))
1530                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1531                        else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1532                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1533                }
1534
1535                /*
1536                 * "--force" will defeat any rejection implemented
1537                 * by the rules above.
1538                 */
1539                if (!force_ref_update)
1540                        ref->status = reject_reason;
1541                else if (reject_reason)
1542                        ref->forced_update = 1;
1543        }
1544}
1545
1546static void set_merge(struct branch *ret)
1547{
1548        struct remote *remote;
1549        char *ref;
1550        struct object_id oid;
1551        int i;
1552
1553        if (!ret)
1554                return; /* no branch */
1555        if (ret->merge)
1556                return; /* already run */
1557        if (!ret->remote_name || !ret->merge_nr) {
1558                /*
1559                 * no merge config; let's make sure we don't confuse callers
1560                 * with a non-zero merge_nr but a NULL merge
1561                 */
1562                ret->merge_nr = 0;
1563                return;
1564        }
1565
1566        remote = remote_get(ret->remote_name);
1567
1568        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1569        for (i = 0; i < ret->merge_nr; i++) {
1570                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1571                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1572                if (!remote_find_tracking(remote, ret->merge[i]) ||
1573                    strcmp(ret->remote_name, "."))
1574                        continue;
1575                if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1576                             &oid, &ref) == 1)
1577                        ret->merge[i]->dst = ref;
1578                else
1579                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1580        }
1581}
1582
1583struct branch *branch_get(const char *name)
1584{
1585        struct branch *ret;
1586
1587        read_config();
1588        if (!name || !*name || !strcmp(name, "HEAD"))
1589                ret = current_branch;
1590        else
1591                ret = make_branch(name, 0);
1592        set_merge(ret);
1593        return ret;
1594}
1595
1596int branch_has_merge_config(struct branch *branch)
1597{
1598        return branch && !!branch->merge;
1599}
1600
1601int branch_merge_matches(struct branch *branch,
1602                                 int i,
1603                                 const char *refname)
1604{
1605        if (!branch || i < 0 || i >= branch->merge_nr)
1606                return 0;
1607        return refname_match(branch->merge[i]->src, refname);
1608}
1609
1610__attribute__((format (printf,2,3)))
1611static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1612{
1613        if (err) {
1614                va_list ap;
1615                va_start(ap, fmt);
1616                strbuf_vaddf(err, fmt, ap);
1617                va_end(ap);
1618        }
1619        return NULL;
1620}
1621
1622const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1623{
1624        if (!branch)
1625                return error_buf(err, _("HEAD does not point to a branch"));
1626
1627        if (!branch->merge || !branch->merge[0]) {
1628                /*
1629                 * no merge config; is it because the user didn't define any,
1630                 * or because it is not a real branch, and get_branch
1631                 * auto-vivified it?
1632                 */
1633                if (!ref_exists(branch->refname))
1634                        return error_buf(err, _("no such branch: '%s'"),
1635                                         branch->name);
1636                return error_buf(err,
1637                                 _("no upstream configured for branch '%s'"),
1638                                 branch->name);
1639        }
1640
1641        if (!branch->merge[0]->dst)
1642                return error_buf(err,
1643                                 _("upstream branch '%s' not stored as a remote-tracking branch"),
1644                                 branch->merge[0]->src);
1645
1646        return branch->merge[0]->dst;
1647}
1648
1649static const char *tracking_for_push_dest(struct remote *remote,
1650                                          const char *refname,
1651                                          struct strbuf *err)
1652{
1653        char *ret;
1654
1655        ret = apply_refspecs(&remote->fetch, refname);
1656        if (!ret)
1657                return error_buf(err,
1658                                 _("push destination '%s' on remote '%s' has no local tracking branch"),
1659                                 refname, remote->name);
1660        return ret;
1661}
1662
1663static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1664{
1665        struct remote *remote;
1666
1667        remote = remote_get(pushremote_for_branch(branch, NULL));
1668        if (!remote)
1669                return error_buf(err,
1670                                 _("branch '%s' has no remote for pushing"),
1671                                 branch->name);
1672
1673        if (remote->push.nr) {
1674                char *dst;
1675                const char *ret;
1676
1677                dst = apply_refspecs(&remote->push, branch->refname);
1678                if (!dst)
1679                        return error_buf(err,
1680                                         _("push refspecs for '%s' do not include '%s'"),
1681                                         remote->name, branch->name);
1682
1683                ret = tracking_for_push_dest(remote, dst, err);
1684                free(dst);
1685                return ret;
1686        }
1687
1688        if (remote->mirror)
1689                return tracking_for_push_dest(remote, branch->refname, err);
1690
1691        switch (push_default) {
1692        case PUSH_DEFAULT_NOTHING:
1693                return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1694
1695        case PUSH_DEFAULT_MATCHING:
1696        case PUSH_DEFAULT_CURRENT:
1697                return tracking_for_push_dest(remote, branch->refname, err);
1698
1699        case PUSH_DEFAULT_UPSTREAM:
1700                return branch_get_upstream(branch, err);
1701
1702        case PUSH_DEFAULT_UNSPECIFIED:
1703        case PUSH_DEFAULT_SIMPLE:
1704                {
1705                        const char *up, *cur;
1706
1707                        up = branch_get_upstream(branch, err);
1708                        if (!up)
1709                                return NULL;
1710                        cur = tracking_for_push_dest(remote, branch->refname, err);
1711                        if (!cur)
1712                                return NULL;
1713                        if (strcmp(cur, up))
1714                                return error_buf(err,
1715                                                 _("cannot resolve 'simple' push to a single destination"));
1716                        return cur;
1717                }
1718        }
1719
1720        BUG("unhandled push situation");
1721}
1722
1723const char *branch_get_push(struct branch *branch, struct strbuf *err)
1724{
1725        if (!branch)
1726                return error_buf(err, _("HEAD does not point to a branch"));
1727
1728        if (!branch->push_tracking_ref)
1729                branch->push_tracking_ref = branch_get_push_1(branch, err);
1730        return branch->push_tracking_ref;
1731}
1732
1733static int ignore_symref_update(const char *refname)
1734{
1735        int flag;
1736
1737        if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
1738                return 0; /* non-existing refs are OK */
1739        return (flag & REF_ISSYMREF);
1740}
1741
1742/*
1743 * Create and return a list of (struct ref) consisting of copies of
1744 * each remote_ref that matches refspec.  refspec must be a pattern.
1745 * Fill in the copies' peer_ref to describe the local tracking refs to
1746 * which they map.  Omit any references that would map to an existing
1747 * local symbolic ref.
1748 */
1749static struct ref *get_expanded_map(const struct ref *remote_refs,
1750                                    const struct refspec_item *refspec)
1751{
1752        const struct ref *ref;
1753        struct ref *ret = NULL;
1754        struct ref **tail = &ret;
1755
1756        for (ref = remote_refs; ref; ref = ref->next) {
1757                char *expn_name = NULL;
1758
1759                if (strchr(ref->name, '^'))
1760                        continue; /* a dereference item */
1761                if (match_name_with_pattern(refspec->src, ref->name,
1762                                            refspec->dst, &expn_name) &&
1763                    !ignore_symref_update(expn_name)) {
1764                        struct ref *cpy = copy_ref(ref);
1765
1766                        cpy->peer_ref = alloc_ref(expn_name);
1767                        if (refspec->force)
1768                                cpy->peer_ref->force = 1;
1769                        *tail = cpy;
1770                        tail = &cpy->next;
1771                }
1772                free(expn_name);
1773        }
1774
1775        return ret;
1776}
1777
1778static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1779{
1780        const struct ref *ref;
1781        const struct ref *best_match = NULL;
1782        int best_score = 0;
1783
1784        for (ref = refs; ref; ref = ref->next) {
1785                int score = refname_match(name, ref->name);
1786
1787                if (best_score < score) {
1788                        best_match = ref;
1789                        best_score = score;
1790                }
1791        }
1792        return best_match;
1793}
1794
1795struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1796{
1797        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1798
1799        if (!ref)
1800                return NULL;
1801
1802        return copy_ref(ref);
1803}
1804
1805static struct ref *get_local_ref(const char *name)
1806{
1807        if (!name || name[0] == '\0')
1808                return NULL;
1809
1810        if (starts_with(name, "refs/"))
1811                return alloc_ref(name);
1812
1813        if (starts_with(name, "heads/") ||
1814            starts_with(name, "tags/") ||
1815            starts_with(name, "remotes/"))
1816                return alloc_ref_with_prefix("refs/", 5, name);
1817
1818        return alloc_ref_with_prefix("refs/heads/", 11, name);
1819}
1820
1821int get_fetch_map(const struct ref *remote_refs,
1822                  const struct refspec_item *refspec,
1823                  struct ref ***tail,
1824                  int missing_ok)
1825{
1826        struct ref *ref_map, **rmp;
1827
1828        if (refspec->pattern) {
1829                ref_map = get_expanded_map(remote_refs, refspec);
1830        } else {
1831                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1832
1833                if (refspec->exact_sha1) {
1834                        ref_map = alloc_ref(name);
1835                        get_oid_hex(name, &ref_map->old_oid);
1836                        ref_map->exact_oid = 1;
1837                } else {
1838                        ref_map = get_remote_ref(remote_refs, name);
1839                }
1840                if (!missing_ok && !ref_map)
1841                        die("Couldn't find remote ref %s", name);
1842                if (ref_map) {
1843                        ref_map->peer_ref = get_local_ref(refspec->dst);
1844                        if (ref_map->peer_ref && refspec->force)
1845                                ref_map->peer_ref->force = 1;
1846                }
1847        }
1848
1849        for (rmp = &ref_map; *rmp; ) {
1850                if ((*rmp)->peer_ref) {
1851                        if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1852                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1853                                struct ref *ignore = *rmp;
1854                                error(_("* Ignoring funny ref '%s' locally"),
1855                                      (*rmp)->peer_ref->name);
1856                                *rmp = (*rmp)->next;
1857                                free(ignore->peer_ref);
1858                                free(ignore);
1859                                continue;
1860                        }
1861                }
1862                rmp = &((*rmp)->next);
1863        }
1864
1865        if (ref_map)
1866                tail_link_ref(ref_map, tail);
1867
1868        return 0;
1869}
1870
1871int resolve_remote_symref(struct ref *ref, struct ref *list)
1872{
1873        if (!ref->symref)
1874                return 0;
1875        for (; list; list = list->next)
1876                if (!strcmp(ref->symref, list->name)) {
1877                        oidcpy(&ref->old_oid, &list->old_oid);
1878                        return 0;
1879                }
1880        return 1;
1881}
1882
1883/*
1884 * Lookup the upstream branch for the given branch and if present, optionally
1885 * compute the commit ahead/behind values for the pair.
1886 *
1887 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
1888 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
1889 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
1890 * set to zero).
1891 *
1892 * The name of the upstream branch (or NULL if no upstream is defined) is
1893 * returned via *upstream_name, if it is not itself NULL.
1894 *
1895 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1896 * upstream defined, or ref does not exist).  Returns 0 if the commits are
1897 * identical.  Returns 1 if commits are different.
1898 */
1899int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1900                       const char **upstream_name, enum ahead_behind_flags abf)
1901{
1902        struct object_id oid;
1903        struct commit *ours, *theirs;
1904        struct rev_info revs;
1905        const char *base;
1906        struct argv_array argv = ARGV_ARRAY_INIT;
1907
1908        /* Cannot stat unless we are marked to build on top of somebody else. */
1909        base = branch_get_upstream(branch, NULL);
1910        if (upstream_name)
1911                *upstream_name = base;
1912        if (!base)
1913                return -1;
1914
1915        /* Cannot stat if what we used to build on no longer exists */
1916        if (read_ref(base, &oid))
1917                return -1;
1918        theirs = lookup_commit_reference(the_repository, &oid);
1919        if (!theirs)
1920                return -1;
1921
1922        if (read_ref(branch->refname, &oid))
1923                return -1;
1924        ours = lookup_commit_reference(the_repository, &oid);
1925        if (!ours)
1926                return -1;
1927
1928        *num_theirs = *num_ours = 0;
1929
1930        /* are we the same? */
1931        if (theirs == ours)
1932                return 0;
1933        if (abf == AHEAD_BEHIND_QUICK)
1934                return 1;
1935        if (abf != AHEAD_BEHIND_FULL)
1936                BUG("stat_tracking_info: invalid abf '%d'", abf);
1937
1938        /* Run "rev-list --left-right ours...theirs" internally... */
1939        argv_array_push(&argv, ""); /* ignored */
1940        argv_array_push(&argv, "--left-right");
1941        argv_array_pushf(&argv, "%s...%s",
1942                         oid_to_hex(&ours->object.oid),
1943                         oid_to_hex(&theirs->object.oid));
1944        argv_array_push(&argv, "--");
1945
1946        repo_init_revisions(the_repository, &revs, NULL);
1947        setup_revisions(argv.argc, argv.argv, &revs, NULL);
1948        if (prepare_revision_walk(&revs))
1949                die("revision walk setup failed");
1950
1951        /* ... and count the commits on each side. */
1952        while (1) {
1953                struct commit *c = get_revision(&revs);
1954                if (!c)
1955                        break;
1956                if (c->object.flags & SYMMETRIC_LEFT)
1957                        (*num_ours)++;
1958                else
1959                        (*num_theirs)++;
1960        }
1961
1962        /* clear object flags smudged by the above traversal */
1963        clear_commit_marks(ours, ALL_REV_FLAGS);
1964        clear_commit_marks(theirs, ALL_REV_FLAGS);
1965
1966        argv_array_clear(&argv);
1967        return 1;
1968}
1969
1970/*
1971 * Return true when there is anything to report, otherwise false.
1972 */
1973int format_tracking_info(struct branch *branch, struct strbuf *sb,
1974                         enum ahead_behind_flags abf)
1975{
1976        int ours, theirs, sti;
1977        const char *full_base;
1978        char *base;
1979        int upstream_is_gone = 0;
1980
1981        sti = stat_tracking_info(branch, &ours, &theirs, &full_base, abf);
1982        if (sti < 0) {
1983                if (!full_base)
1984                        return 0;
1985                upstream_is_gone = 1;
1986        }
1987
1988        base = shorten_unambiguous_ref(full_base, 0);
1989        if (upstream_is_gone) {
1990                strbuf_addf(sb,
1991                        _("Your branch is based on '%s', but the upstream is gone.\n"),
1992                        base);
1993                if (advice_status_hints)
1994                        strbuf_addstr(sb,
1995                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1996        } else if (!sti) {
1997                strbuf_addf(sb,
1998                        _("Your branch is up to date with '%s'.\n"),
1999                        base);
2000        } else if (abf == AHEAD_BEHIND_QUICK) {
2001                strbuf_addf(sb,
2002                            _("Your branch and '%s' refer to different commits.\n"),
2003                            base);
2004                if (advice_status_hints)
2005                        strbuf_addf(sb, _("  (use \"%s\" for details)\n"),
2006                                    "git status --ahead-behind");
2007        } else if (!theirs) {
2008                strbuf_addf(sb,
2009                        Q_("Your branch is ahead of '%s' by %d commit.\n",
2010                           "Your branch is ahead of '%s' by %d commits.\n",
2011                           ours),
2012                        base, ours);
2013                if (advice_status_hints)
2014                        strbuf_addstr(sb,
2015                                _("  (use \"git push\" to publish your local commits)\n"));
2016        } else if (!ours) {
2017                strbuf_addf(sb,
2018                        Q_("Your branch is behind '%s' by %d commit, "
2019                               "and can be fast-forwarded.\n",
2020                           "Your branch is behind '%s' by %d commits, "
2021                               "and can be fast-forwarded.\n",
2022                           theirs),
2023                        base, theirs);
2024                if (advice_status_hints)
2025                        strbuf_addstr(sb,
2026                                _("  (use \"git pull\" to update your local branch)\n"));
2027        } else {
2028                strbuf_addf(sb,
2029                        Q_("Your branch and '%s' have diverged,\n"
2030                               "and have %d and %d different commit each, "
2031                               "respectively.\n",
2032                           "Your branch and '%s' have diverged,\n"
2033                               "and have %d and %d different commits each, "
2034                               "respectively.\n",
2035                           ours + theirs),
2036                        base, ours, theirs);
2037                if (advice_status_hints)
2038                        strbuf_addstr(sb,
2039                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2040        }
2041        free(base);
2042        return 1;
2043}
2044
2045static int one_local_ref(const char *refname, const struct object_id *oid,
2046                         int flag, void *cb_data)
2047{
2048        struct ref ***local_tail = cb_data;
2049        struct ref *ref;
2050
2051        /* we already know it starts with refs/ to get here */
2052        if (check_refname_format(refname + 5, 0))
2053                return 0;
2054
2055        ref = alloc_ref(refname);
2056        oidcpy(&ref->new_oid, oid);
2057        **local_tail = ref;
2058        *local_tail = &ref->next;
2059        return 0;
2060}
2061
2062struct ref *get_local_heads(void)
2063{
2064        struct ref *local_refs = NULL, **local_tail = &local_refs;
2065
2066        for_each_ref(one_local_ref, &local_tail);
2067        return local_refs;
2068}
2069
2070struct ref *guess_remote_head(const struct ref *head,
2071                              const struct ref *refs,
2072                              int all)
2073{
2074        const struct ref *r;
2075        struct ref *list = NULL;
2076        struct ref **tail = &list;
2077
2078        if (!head)
2079                return NULL;
2080
2081        /*
2082         * Some transports support directly peeking at
2083         * where HEAD points; if that is the case, then
2084         * we don't have to guess.
2085         */
2086        if (head->symref)
2087                return copy_ref(find_ref_by_name(refs, head->symref));
2088
2089        /* If refs/heads/master could be right, it is. */
2090        if (!all) {
2091                r = find_ref_by_name(refs, "refs/heads/master");
2092                if (r && oideq(&r->old_oid, &head->old_oid))
2093                        return copy_ref(r);
2094        }
2095
2096        /* Look for another ref that points there */
2097        for (r = refs; r; r = r->next) {
2098                if (r != head &&
2099                    starts_with(r->name, "refs/heads/") &&
2100                    oideq(&r->old_oid, &head->old_oid)) {
2101                        *tail = copy_ref(r);
2102                        tail = &((*tail)->next);
2103                        if (!all)
2104                                break;
2105                }
2106        }
2107
2108        return list;
2109}
2110
2111struct stale_heads_info {
2112        struct string_list *ref_names;
2113        struct ref **stale_refs_tail;
2114        struct refspec *rs;
2115};
2116
2117static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2118                              int flags, void *cb_data)
2119{
2120        struct stale_heads_info *info = cb_data;
2121        struct string_list matches = STRING_LIST_INIT_DUP;
2122        struct refspec_item query;
2123        int i, stale = 1;
2124        memset(&query, 0, sizeof(struct refspec_item));
2125        query.dst = (char *)refname;
2126
2127        query_refspecs_multiple(info->rs, &query, &matches);
2128        if (matches.nr == 0)
2129                goto clean_exit; /* No matches */
2130
2131        /*
2132         * If we did find a suitable refspec and it's not a symref and
2133         * it's not in the list of refs that currently exist in that
2134         * remote, we consider it to be stale. In order to deal with
2135         * overlapping refspecs, we need to go over all of the
2136         * matching refs.
2137         */
2138        if (flags & REF_ISSYMREF)
2139                goto clean_exit;
2140
2141        for (i = 0; stale && i < matches.nr; i++)
2142                if (string_list_has_string(info->ref_names, matches.items[i].string))
2143                        stale = 0;
2144
2145        if (stale) {
2146                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2147                oidcpy(&ref->new_oid, oid);
2148        }
2149
2150clean_exit:
2151        string_list_clear(&matches, 0);
2152        return 0;
2153}
2154
2155struct ref *get_stale_heads(struct refspec *rs, struct ref *fetch_map)
2156{
2157        struct ref *ref, *stale_refs = NULL;
2158        struct string_list ref_names = STRING_LIST_INIT_NODUP;
2159        struct stale_heads_info info;
2160
2161        info.ref_names = &ref_names;
2162        info.stale_refs_tail = &stale_refs;
2163        info.rs = rs;
2164        for (ref = fetch_map; ref; ref = ref->next)
2165                string_list_append(&ref_names, ref->name);
2166        string_list_sort(&ref_names);
2167        for_each_ref(get_stale_heads_cb, &info);
2168        string_list_clear(&ref_names, 0);
2169        return stale_refs;
2170}
2171
2172/*
2173 * Compare-and-swap
2174 */
2175static void clear_cas_option(struct push_cas_option *cas)
2176{
2177        int i;
2178
2179        for (i = 0; i < cas->nr; i++)
2180                free(cas->entry[i].refname);
2181        free(cas->entry);
2182        memset(cas, 0, sizeof(*cas));
2183}
2184
2185static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2186                                      const char *refname,
2187                                      size_t refnamelen)
2188{
2189        struct push_cas *entry;
2190        ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2191        entry = &cas->entry[cas->nr++];
2192        memset(entry, 0, sizeof(*entry));
2193        entry->refname = xmemdupz(refname, refnamelen);
2194        return entry;
2195}
2196
2197static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2198{
2199        const char *colon;
2200        struct push_cas *entry;
2201
2202        if (unset) {
2203                /* "--no-<option>" */
2204                clear_cas_option(cas);
2205                return 0;
2206        }
2207
2208        if (!arg) {
2209                /* just "--<option>" */
2210                cas->use_tracking_for_rest = 1;
2211                return 0;
2212        }
2213
2214        /* "--<option>=refname" or "--<option>=refname:value" */
2215        colon = strchrnul(arg, ':');
2216        entry = add_cas_entry(cas, arg, colon - arg);
2217        if (!*colon)
2218                entry->use_tracking = 1;
2219        else if (!colon[1])
2220                oidclr(&entry->expect);
2221        else if (get_oid(colon + 1, &entry->expect))
2222                return error(_("cannot parse expected object name '%s'"), colon + 1);
2223        return 0;
2224}
2225
2226int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2227{
2228        return parse_push_cas_option(opt->value, arg, unset);
2229}
2230
2231int is_empty_cas(const struct push_cas_option *cas)
2232{
2233        return !cas->use_tracking_for_rest && !cas->nr;
2234}
2235
2236/*
2237 * Look at remote.fetch refspec and see if we have a remote
2238 * tracking branch for the refname there.  Fill its current
2239 * value in sha1[].
2240 * If we cannot do so, return negative to signal an error.
2241 */
2242static int remote_tracking(struct remote *remote, const char *refname,
2243                           struct object_id *oid)
2244{
2245        char *dst;
2246
2247        dst = apply_refspecs(&remote->fetch, refname);
2248        if (!dst)
2249                return -1; /* no tracking ref for refname at remote */
2250        if (read_ref(dst, oid))
2251                return -1; /* we know what the tracking ref is but we cannot read it */
2252        return 0;
2253}
2254
2255static void apply_cas(struct push_cas_option *cas,
2256                      struct remote *remote,
2257                      struct ref *ref)
2258{
2259        int i;
2260
2261        /* Find an explicit --<option>=<name>[:<value>] entry */
2262        for (i = 0; i < cas->nr; i++) {
2263                struct push_cas *entry = &cas->entry[i];
2264                if (!refname_match(entry->refname, ref->name))
2265                        continue;
2266                ref->expect_old_sha1 = 1;
2267                if (!entry->use_tracking)
2268                        oidcpy(&ref->old_oid_expect, &entry->expect);
2269                else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2270                        oidclr(&ref->old_oid_expect);
2271                return;
2272        }
2273
2274        /* Are we using "--<option>" to cover all? */
2275        if (!cas->use_tracking_for_rest)
2276                return;
2277
2278        ref->expect_old_sha1 = 1;
2279        if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2280                oidclr(&ref->old_oid_expect);
2281}
2282
2283void apply_push_cas(struct push_cas_option *cas,
2284                    struct remote *remote,
2285                    struct ref *remote_refs)
2286{
2287        struct ref *ref;
2288        for (ref = remote_refs; ref; ref = ref->next)
2289                apply_cas(cas, remote, ref);
2290}