remote.con commit Merge branch 'es/mw-to-git-chain-fix' (c5c26f7)
   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
  16enum map_direction { FROM_SRC, FROM_DST };
  17
  18struct counted_string {
  19        size_t len;
  20        const char *s;
  21};
  22struct rewrite {
  23        const char *base;
  24        size_t baselen;
  25        struct counted_string *instead_of;
  26        int instead_of_nr;
  27        int instead_of_alloc;
  28};
  29struct rewrites {
  30        struct rewrite **rewrite;
  31        int rewrite_alloc;
  32        int rewrite_nr;
  33};
  34
  35static struct remote **remotes;
  36static int remotes_alloc;
  37static int remotes_nr;
  38static struct hashmap remotes_hash;
  39
  40static struct branch **branches;
  41static int branches_alloc;
  42static int branches_nr;
  43
  44static struct branch *current_branch;
  45static const char *pushremote_name;
  46
  47static struct rewrites rewrites;
  48static struct rewrites rewrites_push;
  49
  50static int valid_remote(const struct remote *remote)
  51{
  52        return (!!remote->url) || (!!remote->foreign_vcs);
  53}
  54
  55static const char *alias_url(const char *url, struct rewrites *r)
  56{
  57        int i, j;
  58        struct counted_string *longest;
  59        int longest_i;
  60
  61        longest = NULL;
  62        longest_i = -1;
  63        for (i = 0; i < r->rewrite_nr; i++) {
  64                if (!r->rewrite[i])
  65                        continue;
  66                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  67                        if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  68                            (!longest ||
  69                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  70                                longest = &(r->rewrite[i]->instead_of[j]);
  71                                longest_i = i;
  72                        }
  73                }
  74        }
  75        if (!longest)
  76                return url;
  77
  78        return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  79}
  80
  81static void add_url(struct remote *remote, const char *url)
  82{
  83        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
  84        remote->url[remote->url_nr++] = url;
  85}
  86
  87static void add_pushurl(struct remote *remote, const char *pushurl)
  88{
  89        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
  90        remote->pushurl[remote->pushurl_nr++] = pushurl;
  91}
  92
  93static void add_pushurl_alias(struct remote *remote, const char *url)
  94{
  95        const char *pushurl = alias_url(url, &rewrites_push);
  96        if (pushurl != url)
  97                add_pushurl(remote, pushurl);
  98}
  99
 100static void add_url_alias(struct remote *remote, const char *url)
 101{
 102        add_url(remote, alias_url(url, &rewrites));
 103        add_pushurl_alias(remote, url);
 104}
 105
 106struct remotes_hash_key {
 107        const char *str;
 108        int len;
 109};
 110
 111static int remotes_hash_cmp(const void *unused_cmp_data,
 112                            const void *entry,
 113                            const void *entry_or_key,
 114                            const void *keydata)
 115{
 116        const struct remote *a = entry;
 117        const struct remote *b = entry_or_key;
 118        const struct remotes_hash_key *key = keydata;
 119
 120        if (key)
 121                return strncmp(a->name, key->str, key->len) || a->name[key->len];
 122        else
 123                return strcmp(a->name, b->name);
 124}
 125
 126static inline void init_remotes_hash(void)
 127{
 128        if (!remotes_hash.cmpfn)
 129                hashmap_init(&remotes_hash, remotes_hash_cmp, NULL, 0);
 130}
 131
 132static struct remote *make_remote(const char *name, int len)
 133{
 134        struct remote *ret, *replaced;
 135        struct remotes_hash_key lookup;
 136        struct hashmap_entry lookup_entry;
 137
 138        if (!len)
 139                len = strlen(name);
 140
 141        init_remotes_hash();
 142        lookup.str = name;
 143        lookup.len = len;
 144        hashmap_entry_init(&lookup_entry, memhash(name, len));
 145
 146        if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 147                return ret;
 148
 149        ret = xcalloc(1, sizeof(struct remote));
 150        ret->prune = -1;  /* unspecified */
 151        ret->prune_tags = -1;  /* unspecified */
 152        ret->name = xstrndup(name, len);
 153        refspec_init(&ret->push, REFSPEC_PUSH);
 154        refspec_init(&ret->fetch, REFSPEC_FETCH);
 155
 156        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 157        remotes[remotes_nr++] = ret;
 158
 159        hashmap_entry_init(ret, lookup_entry.hash);
 160        replaced = hashmap_put(&remotes_hash, ret);
 161        assert(replaced == NULL);  /* no previous entry overwritten */
 162        return ret;
 163}
 164
 165static void add_merge(struct branch *branch, const char *name)
 166{
 167        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 168                   branch->merge_alloc);
 169        branch->merge_name[branch->merge_nr++] = name;
 170}
 171
 172static struct branch *make_branch(const char *name, int len)
 173{
 174        struct branch *ret;
 175        int i;
 176
 177        for (i = 0; i < branches_nr; i++) {
 178                if (len ? (!strncmp(name, branches[i]->name, len) &&
 179                           !branches[i]->name[len]) :
 180                    !strcmp(name, branches[i]->name))
 181                        return branches[i];
 182        }
 183
 184        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 185        ret = xcalloc(1, sizeof(struct branch));
 186        branches[branches_nr++] = ret;
 187        if (len)
 188                ret->name = xstrndup(name, len);
 189        else
 190                ret->name = xstrdup(name);
 191        ret->refname = xstrfmt("refs/heads/%s", ret->name);
 192
 193        return ret;
 194}
 195
 196static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 197{
 198        struct rewrite *ret;
 199        int i;
 200
 201        for (i = 0; i < r->rewrite_nr; i++) {
 202                if (len
 203                    ? (len == r->rewrite[i]->baselen &&
 204                       !strncmp(base, r->rewrite[i]->base, len))
 205                    : !strcmp(base, r->rewrite[i]->base))
 206                        return r->rewrite[i];
 207        }
 208
 209        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 210        ret = xcalloc(1, sizeof(struct rewrite));
 211        r->rewrite[r->rewrite_nr++] = ret;
 212        if (len) {
 213                ret->base = xstrndup(base, len);
 214                ret->baselen = len;
 215        }
 216        else {
 217                ret->base = xstrdup(base);
 218                ret->baselen = strlen(base);
 219        }
 220        return ret;
 221}
 222
 223static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 224{
 225        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 226        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 227        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 228        rewrite->instead_of_nr++;
 229}
 230
 231static const char *skip_spaces(const char *s)
 232{
 233        while (isspace(*s))
 234                s++;
 235        return s;
 236}
 237
 238static void read_remotes_file(struct remote *remote)
 239{
 240        struct strbuf buf = STRBUF_INIT;
 241        FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");
 242
 243        if (!f)
 244                return;
 245        remote->configured_in_repo = 1;
 246        remote->origin = REMOTE_REMOTES;
 247        while (strbuf_getline(&buf, f) != EOF) {
 248                const char *v;
 249
 250                strbuf_rtrim(&buf);
 251
 252                if (skip_prefix(buf.buf, "URL:", &v))
 253                        add_url_alias(remote, xstrdup(skip_spaces(v)));
 254                else if (skip_prefix(buf.buf, "Push:", &v))
 255                        refspec_append(&remote->push, skip_spaces(v));
 256                else if (skip_prefix(buf.buf, "Pull:", &v))
 257                        refspec_append(&remote->fetch, skip_spaces(v));
 258        }
 259        strbuf_release(&buf);
 260        fclose(f);
 261}
 262
 263static void read_branches_file(struct remote *remote)
 264{
 265        char *frag;
 266        struct strbuf buf = STRBUF_INIT;
 267        FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");
 268
 269        if (!f)
 270                return;
 271
 272        strbuf_getline_lf(&buf, f);
 273        fclose(f);
 274        strbuf_trim(&buf);
 275        if (!buf.len) {
 276                strbuf_release(&buf);
 277                return;
 278        }
 279
 280        remote->configured_in_repo = 1;
 281        remote->origin = REMOTE_BRANCHES;
 282
 283        /*
 284         * The branches file would have URL and optionally
 285         * #branch specified.  The "master" (or specified) branch is
 286         * fetched and stored in the local branch matching the
 287         * remote name.
 288         */
 289        frag = strchr(buf.buf, '#');
 290        if (frag)
 291                *(frag++) = '\0';
 292        else
 293                frag = "master";
 294
 295        add_url_alias(remote, strbuf_detach(&buf, NULL));
 296        strbuf_addf(&buf, "refs/heads/%s:refs/heads/%s",
 297                    frag, remote->name);
 298        refspec_append(&remote->fetch, buf.buf);
 299
 300        /*
 301         * Cogito compatible push: push current HEAD to remote #branch
 302         * (master if missing)
 303         */
 304        strbuf_reset(&buf);
 305        strbuf_addf(&buf, "HEAD:refs/heads/%s", frag);
 306        refspec_append(&remote->push, buf.buf);
 307        remote->fetch_tags = 1; /* always auto-follow */
 308        strbuf_release(&buf);
 309}
 310
 311static int handle_config(const char *key, const char *value, void *cb)
 312{
 313        const char *name;
 314        int namelen;
 315        const char *subkey;
 316        struct remote *remote;
 317        struct branch *branch;
 318        if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 319                if (!name)
 320                        return 0;
 321                branch = make_branch(name, namelen);
 322                if (!strcmp(subkey, "remote")) {
 323                        return git_config_string(&branch->remote_name, key, value);
 324                } else if (!strcmp(subkey, "pushremote")) {
 325                        return git_config_string(&branch->pushremote_name, key, value);
 326                } else if (!strcmp(subkey, "merge")) {
 327                        if (!value)
 328                                return config_error_nonbool(key);
 329                        add_merge(branch, xstrdup(value));
 330                }
 331                return 0;
 332        }
 333        if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 334                struct rewrite *rewrite;
 335                if (!name)
 336                        return 0;
 337                if (!strcmp(subkey, "insteadof")) {
 338                        rewrite = make_rewrite(&rewrites, name, namelen);
 339                        if (!value)
 340                                return config_error_nonbool(key);
 341                        add_instead_of(rewrite, xstrdup(value));
 342                } else if (!strcmp(subkey, "pushinsteadof")) {
 343                        rewrite = make_rewrite(&rewrites_push, name, namelen);
 344                        if (!value)
 345                                return config_error_nonbool(key);
 346                        add_instead_of(rewrite, xstrdup(value));
 347                }
 348        }
 349
 350        if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 351                return 0;
 352
 353        /* Handle remote.* variables */
 354        if (!name && !strcmp(subkey, "pushdefault"))
 355                return git_config_string(&pushremote_name, key, value);
 356
 357        if (!name)
 358                return 0;
 359        /* Handle remote.<name>.* variables */
 360        if (*name == '/') {
 361                warning("Config remote shorthand cannot begin with '/': %s",
 362                        name);
 363                return 0;
 364        }
 365        remote = make_remote(name, namelen);
 366        remote->origin = REMOTE_CONFIG;
 367        if (current_config_scope() == CONFIG_SCOPE_REPO)
 368                remote->configured_in_repo = 1;
 369        if (!strcmp(subkey, "mirror"))
 370                remote->mirror = git_config_bool(key, value);
 371        else if (!strcmp(subkey, "skipdefaultupdate"))
 372                remote->skip_default_update = git_config_bool(key, value);
 373        else if (!strcmp(subkey, "skipfetchall"))
 374                remote->skip_default_update = git_config_bool(key, value);
 375        else if (!strcmp(subkey, "prune"))
 376                remote->prune = git_config_bool(key, value);
 377        else if (!strcmp(subkey, "prunetags"))
 378                remote->prune_tags = git_config_bool(key, value);
 379        else if (!strcmp(subkey, "url")) {
 380                const char *v;
 381                if (git_config_string(&v, key, value))
 382                        return -1;
 383                add_url(remote, v);
 384        } else if (!strcmp(subkey, "pushurl")) {
 385                const char *v;
 386                if (git_config_string(&v, key, value))
 387                        return -1;
 388                add_pushurl(remote, v);
 389        } else if (!strcmp(subkey, "push")) {
 390                const char *v;
 391                if (git_config_string(&v, key, value))
 392                        return -1;
 393                refspec_append(&remote->push, v);
 394                free((char *)v);
 395        } else if (!strcmp(subkey, "fetch")) {
 396                const char *v;
 397                if (git_config_string(&v, key, value))
 398                        return -1;
 399                refspec_append(&remote->fetch, v);
 400                free((char *)v);
 401        } else if (!strcmp(subkey, "receivepack")) {
 402                const char *v;
 403                if (git_config_string(&v, key, value))
 404                        return -1;
 405                if (!remote->receivepack)
 406                        remote->receivepack = v;
 407                else
 408                        error("more than one receivepack given, using the first");
 409        } else if (!strcmp(subkey, "uploadpack")) {
 410                const char *v;
 411                if (git_config_string(&v, key, value))
 412                        return -1;
 413                if (!remote->uploadpack)
 414                        remote->uploadpack = v;
 415                else
 416                        error("more than one uploadpack given, using the first");
 417        } else if (!strcmp(subkey, "tagopt")) {
 418                if (!strcmp(value, "--no-tags"))
 419                        remote->fetch_tags = -1;
 420                else if (!strcmp(value, "--tags"))
 421                        remote->fetch_tags = 2;
 422        } else if (!strcmp(subkey, "proxy")) {
 423                return git_config_string((const char **)&remote->http_proxy,
 424                                         key, value);
 425        } else if (!strcmp(subkey, "proxyauthmethod")) {
 426                return git_config_string((const char **)&remote->http_proxy_authmethod,
 427                                         key, value);
 428        } else if (!strcmp(subkey, "vcs")) {
 429                return git_config_string(&remote->foreign_vcs, key, value);
 430        }
 431        return 0;
 432}
 433
 434static void alias_all_urls(void)
 435{
 436        int i, j;
 437        for (i = 0; i < remotes_nr; i++) {
 438                int add_pushurl_aliases;
 439                if (!remotes[i])
 440                        continue;
 441                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 442                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 443                }
 444                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 445                for (j = 0; j < remotes[i]->url_nr; j++) {
 446                        if (add_pushurl_aliases)
 447                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 448                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 449                }
 450        }
 451}
 452
 453static void read_config(void)
 454{
 455        static int loaded;
 456        int flag;
 457
 458        if (loaded)
 459                return;
 460        loaded = 1;
 461
 462        current_branch = NULL;
 463        if (startup_info->have_repository) {
 464                const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
 465                if (head_ref && (flag & REF_ISSYMREF) &&
 466                    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 467                        current_branch = make_branch(head_ref, 0);
 468                }
 469        }
 470        git_config(handle_config, NULL);
 471        alias_all_urls();
 472}
 473
 474static int valid_remote_nick(const char *name)
 475{
 476        if (!name[0] || is_dot_or_dotdot(name))
 477                return 0;
 478
 479        /* remote nicknames cannot contain slashes */
 480        while (*name)
 481                if (is_dir_sep(*name++))
 482                        return 0;
 483        return 1;
 484}
 485
 486const char *remote_for_branch(struct branch *branch, int *explicit)
 487{
 488        if (branch && branch->remote_name) {
 489                if (explicit)
 490                        *explicit = 1;
 491                return branch->remote_name;
 492        }
 493        if (explicit)
 494                *explicit = 0;
 495        return "origin";
 496}
 497
 498const char *pushremote_for_branch(struct branch *branch, int *explicit)
 499{
 500        if (branch && branch->pushremote_name) {
 501                if (explicit)
 502                        *explicit = 1;
 503                return branch->pushremote_name;
 504        }
 505        if (pushremote_name) {
 506                if (explicit)
 507                        *explicit = 1;
 508                return pushremote_name;
 509        }
 510        return remote_for_branch(branch, explicit);
 511}
 512
 513const char *remote_ref_for_branch(struct branch *branch, int for_push,
 514                                  int *explicit)
 515{
 516        if (branch) {
 517                if (!for_push) {
 518                        if (branch->merge_nr) {
 519                                if (explicit)
 520                                        *explicit = 1;
 521                                return branch->merge_name[0];
 522                        }
 523                } else {
 524                        const char *dst, *remote_name =
 525                                pushremote_for_branch(branch, NULL);
 526                        struct remote *remote = remote_get(remote_name);
 527
 528                        if (remote && remote->push.nr &&
 529                            (dst = apply_refspecs(&remote->push,
 530                                                  branch->refname))) {
 531                                if (explicit)
 532                                        *explicit = 1;
 533                                return dst;
 534                        }
 535                }
 536        }
 537        if (explicit)
 538                *explicit = 0;
 539        return "";
 540}
 541
 542static struct remote *remote_get_1(const char *name,
 543                                   const char *(*get_default)(struct branch *, int *))
 544{
 545        struct remote *ret;
 546        int name_given = 0;
 547
 548        read_config();
 549
 550        if (name)
 551                name_given = 1;
 552        else
 553                name = get_default(current_branch, &name_given);
 554
 555        ret = make_remote(name, 0);
 556        if (valid_remote_nick(name) && have_git_dir()) {
 557                if (!valid_remote(ret))
 558                        read_remotes_file(ret);
 559                if (!valid_remote(ret))
 560                        read_branches_file(ret);
 561        }
 562        if (name_given && !valid_remote(ret))
 563                add_url_alias(ret, name);
 564        if (!valid_remote(ret))
 565                return NULL;
 566        return ret;
 567}
 568
 569struct remote *remote_get(const char *name)
 570{
 571        return remote_get_1(name, remote_for_branch);
 572}
 573
 574struct remote *pushremote_get(const char *name)
 575{
 576        return remote_get_1(name, pushremote_for_branch);
 577}
 578
 579int remote_is_configured(struct remote *remote, int in_repo)
 580{
 581        if (!remote)
 582                return 0;
 583        if (in_repo)
 584                return remote->configured_in_repo;
 585        return !!remote->origin;
 586}
 587
 588int for_each_remote(each_remote_fn fn, void *priv)
 589{
 590        int i, result = 0;
 591        read_config();
 592        for (i = 0; i < remotes_nr && !result; i++) {
 593                struct remote *r = remotes[i];
 594                if (!r)
 595                        continue;
 596                result = fn(r, priv);
 597        }
 598        return result;
 599}
 600
 601static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 602{
 603        if (strcmp(ref1->name, ref2->name)) {
 604                if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 605                    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 606                        die(_("Cannot fetch both %s and %s to %s"),
 607                            ref1->name, ref2->name, ref2->peer_ref->name);
 608                } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 609                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 610                        warning(_("%s usually tracks %s, not %s"),
 611                                ref2->peer_ref->name, ref2->name, ref1->name);
 612                } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 613                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 614                        die(_("%s tracks both %s and %s"),
 615                            ref2->peer_ref->name, ref1->name, ref2->name);
 616                } else {
 617                        /*
 618                         * This last possibility doesn't occur because
 619                         * FETCH_HEAD_IGNORE entries always appear at
 620                         * the end of the list.
 621                         */
 622                        die(_("Internal error"));
 623                }
 624        }
 625        free(ref2->peer_ref);
 626        free(ref2);
 627}
 628
 629struct ref *ref_remove_duplicates(struct ref *ref_map)
 630{
 631        struct string_list refs = STRING_LIST_INIT_NODUP;
 632        struct ref *retval = NULL;
 633        struct ref **p = &retval;
 634
 635        while (ref_map) {
 636                struct ref *ref = ref_map;
 637
 638                ref_map = ref_map->next;
 639                ref->next = NULL;
 640
 641                if (!ref->peer_ref) {
 642                        *p = ref;
 643                        p = &ref->next;
 644                } else {
 645                        struct string_list_item *item =
 646                                string_list_insert(&refs, ref->peer_ref->name);
 647
 648                        if (item->util) {
 649                                /* Entry already existed */
 650                                handle_duplicate((struct ref *)item->util, ref);
 651                        } else {
 652                                *p = ref;
 653                                p = &ref->next;
 654                                item->util = ref;
 655                        }
 656                }
 657        }
 658
 659        string_list_clear(&refs, 0);
 660        return retval;
 661}
 662
 663int remote_has_url(struct remote *remote, const char *url)
 664{
 665        int i;
 666        for (i = 0; i < remote->url_nr; i++) {
 667                if (!strcmp(remote->url[i], url))
 668                        return 1;
 669        }
 670        return 0;
 671}
 672
 673static int match_name_with_pattern(const char *key, const char *name,
 674                                   const char *value, char **result)
 675{
 676        const char *kstar = strchr(key, '*');
 677        size_t klen;
 678        size_t ksuffixlen;
 679        size_t namelen;
 680        int ret;
 681        if (!kstar)
 682                die("Key '%s' of pattern had no '*'", key);
 683        klen = kstar - key;
 684        ksuffixlen = strlen(kstar + 1);
 685        namelen = strlen(name);
 686        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 687                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 688        if (ret && value) {
 689                struct strbuf sb = STRBUF_INIT;
 690                const char *vstar = strchr(value, '*');
 691                if (!vstar)
 692                        die("Value '%s' of pattern has no '*'", value);
 693                strbuf_add(&sb, value, vstar - value);
 694                strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 695                strbuf_addstr(&sb, vstar + 1);
 696                *result = strbuf_detach(&sb, NULL);
 697        }
 698        return ret;
 699}
 700
 701static void query_refspecs_multiple(struct refspec *rs,
 702                                    struct refspec_item *query,
 703                                    struct string_list *results)
 704{
 705        int i;
 706        int find_src = !query->src;
 707
 708        if (find_src && !query->dst)
 709                error("query_refspecs_multiple: need either src or dst");
 710
 711        for (i = 0; i < rs->nr; i++) {
 712                struct refspec_item *refspec = &rs->items[i];
 713                const char *key = find_src ? refspec->dst : refspec->src;
 714                const char *value = find_src ? refspec->src : refspec->dst;
 715                const char *needle = find_src ? query->dst : query->src;
 716                char **result = find_src ? &query->src : &query->dst;
 717
 718                if (!refspec->dst)
 719                        continue;
 720                if (refspec->pattern) {
 721                        if (match_name_with_pattern(key, needle, value, result))
 722                                string_list_append_nodup(results, *result);
 723                } else if (!strcmp(needle, key)) {
 724                        string_list_append(results, value);
 725                }
 726        }
 727}
 728
 729int query_refspecs(struct refspec *rs, struct refspec_item *query)
 730{
 731        int i;
 732        int find_src = !query->src;
 733        const char *needle = find_src ? query->dst : query->src;
 734        char **result = find_src ? &query->src : &query->dst;
 735
 736        if (find_src && !query->dst)
 737                return error("query_refspecs: need either src or dst");
 738
 739        for (i = 0; i < rs->nr; i++) {
 740                struct refspec_item *refspec = &rs->items[i];
 741                const char *key = find_src ? refspec->dst : refspec->src;
 742                const char *value = find_src ? refspec->src : refspec->dst;
 743
 744                if (!refspec->dst)
 745                        continue;
 746                if (refspec->pattern) {
 747                        if (match_name_with_pattern(key, needle, value, result)) {
 748                                query->force = refspec->force;
 749                                return 0;
 750                        }
 751                } else if (!strcmp(needle, key)) {
 752                        *result = xstrdup(value);
 753                        query->force = refspec->force;
 754                        return 0;
 755                }
 756        }
 757        return -1;
 758}
 759
 760char *apply_refspecs(struct refspec *rs, const char *name)
 761{
 762        struct refspec_item query;
 763
 764        memset(&query, 0, sizeof(struct refspec_item));
 765        query.src = (char *)name;
 766
 767        if (query_refspecs(rs, &query))
 768                return NULL;
 769
 770        return query.dst;
 771}
 772
 773int remote_find_tracking(struct remote *remote, struct refspec_item *refspec)
 774{
 775        return query_refspecs(&remote->fetch, refspec);
 776}
 777
 778static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 779                const char *name)
 780{
 781        size_t len = strlen(name);
 782        struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 783        memcpy(ref->name, prefix, prefixlen);
 784        memcpy(ref->name + prefixlen, name, len);
 785        return ref;
 786}
 787
 788struct ref *alloc_ref(const char *name)
 789{
 790        return alloc_ref_with_prefix("", 0, name);
 791}
 792
 793struct ref *copy_ref(const struct ref *ref)
 794{
 795        struct ref *cpy;
 796        size_t len;
 797        if (!ref)
 798                return NULL;
 799        len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 800        cpy = xmalloc(len);
 801        memcpy(cpy, ref, len);
 802        cpy->next = NULL;
 803        cpy->symref = xstrdup_or_null(ref->symref);
 804        cpy->remote_status = xstrdup_or_null(ref->remote_status);
 805        cpy->peer_ref = copy_ref(ref->peer_ref);
 806        return cpy;
 807}
 808
 809struct ref *copy_ref_list(const struct ref *ref)
 810{
 811        struct ref *ret = NULL;
 812        struct ref **tail = &ret;
 813        while (ref) {
 814                *tail = copy_ref(ref);
 815                ref = ref->next;
 816                tail = &((*tail)->next);
 817        }
 818        return ret;
 819}
 820
 821static void free_ref(struct ref *ref)
 822{
 823        if (!ref)
 824                return;
 825        free_ref(ref->peer_ref);
 826        free(ref->remote_status);
 827        free(ref->symref);
 828        free(ref);
 829}
 830
 831void free_refs(struct ref *ref)
 832{
 833        struct ref *next;
 834        while (ref) {
 835                next = ref->next;
 836                free_ref(ref);
 837                ref = next;
 838        }
 839}
 840
 841int ref_compare_name(const void *va, const void *vb)
 842{
 843        const struct ref *a = va, *b = vb;
 844        return strcmp(a->name, b->name);
 845}
 846
 847static void *ref_list_get_next(const void *a)
 848{
 849        return ((const struct ref *)a)->next;
 850}
 851
 852static void ref_list_set_next(void *a, void *next)
 853{
 854        ((struct ref *)a)->next = next;
 855}
 856
 857void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 858{
 859        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 860}
 861
 862int count_refspec_match(const char *pattern,
 863                        struct ref *refs,
 864                        struct ref **matched_ref)
 865{
 866        int patlen = strlen(pattern);
 867        struct ref *matched_weak = NULL;
 868        struct ref *matched = NULL;
 869        int weak_match = 0;
 870        int match = 0;
 871
 872        for (weak_match = match = 0; refs; refs = refs->next) {
 873                char *name = refs->name;
 874                int namelen = strlen(name);
 875
 876                if (!refname_match(pattern, name))
 877                        continue;
 878
 879                /* A match is "weak" if it is with refs outside
 880                 * heads or tags, and did not specify the pattern
 881                 * in full (e.g. "refs/remotes/origin/master") or at
 882                 * least from the toplevel (e.g. "remotes/origin/master");
 883                 * otherwise "git push $URL master" would result in
 884                 * ambiguity between remotes/origin/master and heads/master
 885                 * at the remote site.
 886                 */
 887                if (namelen != patlen &&
 888                    patlen != namelen - 5 &&
 889                    !starts_with(name, "refs/heads/") &&
 890                    !starts_with(name, "refs/tags/")) {
 891                        /* We want to catch the case where only weak
 892                         * matches are found and there are multiple
 893                         * matches, and where more than one strong
 894                         * matches are found, as ambiguous.  One
 895                         * strong match with zero or more weak matches
 896                         * are acceptable as a unique match.
 897                         */
 898                        matched_weak = refs;
 899                        weak_match++;
 900                }
 901                else {
 902                        matched = refs;
 903                        match++;
 904                }
 905        }
 906        if (!matched) {
 907                if (matched_ref)
 908                        *matched_ref = matched_weak;
 909                return weak_match;
 910        }
 911        else {
 912                if (matched_ref)
 913                        *matched_ref = matched;
 914                return match;
 915        }
 916}
 917
 918static void tail_link_ref(struct ref *ref, struct ref ***tail)
 919{
 920        **tail = ref;
 921        while (ref->next)
 922                ref = ref->next;
 923        *tail = &ref->next;
 924}
 925
 926static struct ref *alloc_delete_ref(void)
 927{
 928        struct ref *ref = alloc_ref("(delete)");
 929        oidclr(&ref->new_oid);
 930        return ref;
 931}
 932
 933static int try_explicit_object_name(const char *name,
 934                                    struct ref **match)
 935{
 936        struct object_id oid;
 937
 938        if (!*name) {
 939                if (match)
 940                        *match = alloc_delete_ref();
 941                return 0;
 942        }
 943
 944        if (get_oid(name, &oid))
 945                return -1;
 946
 947        if (match) {
 948                *match = alloc_ref(name);
 949                oidcpy(&(*match)->new_oid, &oid);
 950        }
 951        return 0;
 952}
 953
 954static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 955{
 956        struct ref *ret = alloc_ref(name);
 957        tail_link_ref(ret, tail);
 958        return ret;
 959}
 960
 961static char *guess_ref(const char *name, struct ref *peer)
 962{
 963        struct strbuf buf = STRBUF_INIT;
 964
 965        const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
 966                                           NULL, NULL);
 967        if (!r)
 968                return NULL;
 969
 970        if (starts_with(r, "refs/heads/"))
 971                strbuf_addstr(&buf, "refs/heads/");
 972        else if (starts_with(r, "refs/tags/"))
 973                strbuf_addstr(&buf, "refs/tags/");
 974        else
 975                return NULL;
 976
 977        strbuf_addstr(&buf, name);
 978        return strbuf_detach(&buf, NULL);
 979}
 980
 981static int match_explicit_lhs(struct ref *src,
 982                              struct refspec_item *rs,
 983                              struct ref **match,
 984                              int *allocated_match)
 985{
 986        switch (count_refspec_match(rs->src, src, match)) {
 987        case 1:
 988                if (allocated_match)
 989                        *allocated_match = 0;
 990                return 0;
 991        case 0:
 992                /* The source could be in the get_sha1() format
 993                 * not a reference name.  :refs/other is a
 994                 * way to delete 'other' ref at the remote end.
 995                 */
 996                if (try_explicit_object_name(rs->src, match) < 0)
 997                        return error("src refspec %s does not match any.", rs->src);
 998                if (allocated_match)
 999                        *allocated_match = 1;
1000                return 0;
1001        default:
1002                return error("src refspec %s matches more than one.", rs->src);
1003        }
1004}
1005
1006static int match_explicit(struct ref *src, struct ref *dst,
1007                          struct ref ***dst_tail,
1008                          struct refspec_item *rs)
1009{
1010        struct ref *matched_src, *matched_dst;
1011        int allocated_src;
1012
1013        const char *dst_value = rs->dst;
1014        char *dst_guess;
1015
1016        if (rs->pattern || rs->matching)
1017                return 0;
1018
1019        matched_src = matched_dst = NULL;
1020        if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1021                return -1;
1022
1023        if (!dst_value) {
1024                int flag;
1025
1026                dst_value = resolve_ref_unsafe(matched_src->name,
1027                                               RESOLVE_REF_READING,
1028                                               NULL, &flag);
1029                if (!dst_value ||
1030                    ((flag & REF_ISSYMREF) &&
1031                     !starts_with(dst_value, "refs/heads/")))
1032                        die("%s cannot be resolved to branch.",
1033                            matched_src->name);
1034        }
1035
1036        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1037        case 1:
1038                break;
1039        case 0:
1040                if (starts_with(dst_value, "refs/"))
1041                        matched_dst = make_linked_ref(dst_value, dst_tail);
1042                else if (is_null_oid(&matched_src->new_oid))
1043                        error("unable to delete '%s': remote ref does not exist",
1044                              dst_value);
1045                else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1046                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1047                        free(dst_guess);
1048                } else
1049                        error("unable to push to unqualified destination: %s\n"
1050                              "The destination refspec neither matches an "
1051                              "existing ref on the remote nor\n"
1052                              "begins with refs/, and we are unable to "
1053                              "guess a prefix based on the source ref.",
1054                              dst_value);
1055                break;
1056        default:
1057                matched_dst = NULL;
1058                error("dst refspec %s matches more than one.",
1059                      dst_value);
1060                break;
1061        }
1062        if (!matched_dst)
1063                return -1;
1064        if (matched_dst->peer_ref)
1065                return error("dst ref %s receives from more than one src.",
1066                      matched_dst->name);
1067        else {
1068                matched_dst->peer_ref = allocated_src ?
1069                                        matched_src :
1070                                        copy_ref(matched_src);
1071                matched_dst->force = rs->force;
1072        }
1073        return 0;
1074}
1075
1076static int match_explicit_refs(struct ref *src, struct ref *dst,
1077                               struct ref ***dst_tail, struct refspec *rs)
1078{
1079        int i, errs;
1080        for (i = errs = 0; i < rs->nr; i++)
1081                errs += match_explicit(src, dst, dst_tail, &rs->items[i]);
1082        return errs;
1083}
1084
1085static char *get_ref_match(const struct refspec *rs, const struct ref *ref,
1086                           int send_mirror, int direction,
1087                           const struct refspec_item **ret_pat)
1088{
1089        const struct refspec_item *pat;
1090        char *name;
1091        int i;
1092        int matching_refs = -1;
1093        for (i = 0; i < rs->nr; i++) {
1094                const struct refspec_item *item = &rs->items[i];
1095                if (item->matching &&
1096                    (matching_refs == -1 || item->force)) {
1097                        matching_refs = i;
1098                        continue;
1099                }
1100
1101                if (item->pattern) {
1102                        const char *dst_side = item->dst ? item->dst : item->src;
1103                        int match;
1104                        if (direction == FROM_SRC)
1105                                match = match_name_with_pattern(item->src, ref->name, dst_side, &name);
1106                        else
1107                                match = match_name_with_pattern(dst_side, ref->name, item->src, &name);
1108                        if (match) {
1109                                matching_refs = i;
1110                                break;
1111                        }
1112                }
1113        }
1114        if (matching_refs == -1)
1115                return NULL;
1116
1117        pat = &rs->items[matching_refs];
1118        if (pat->matching) {
1119                /*
1120                 * "matching refs"; traditionally we pushed everything
1121                 * including refs outside refs/heads/ hierarchy, but
1122                 * that does not make much sense these days.
1123                 */
1124                if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1125                        return NULL;
1126                name = xstrdup(ref->name);
1127        }
1128        if (ret_pat)
1129                *ret_pat = pat;
1130        return name;
1131}
1132
1133static struct ref **tail_ref(struct ref **head)
1134{
1135        struct ref **tail = head;
1136        while (*tail)
1137                tail = &((*tail)->next);
1138        return tail;
1139}
1140
1141struct tips {
1142        struct commit **tip;
1143        int nr, alloc;
1144};
1145
1146static void add_to_tips(struct tips *tips, const struct object_id *oid)
1147{
1148        struct commit *commit;
1149
1150        if (is_null_oid(oid))
1151                return;
1152        commit = lookup_commit_reference_gently(the_repository, oid, 1);
1153        if (!commit || (commit->object.flags & TMP_MARK))
1154                return;
1155        commit->object.flags |= TMP_MARK;
1156        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1157        tips->tip[tips->nr++] = commit;
1158}
1159
1160static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1161{
1162        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1163        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1164        struct string_list_item *item;
1165        struct ref *ref;
1166        struct tips sent_tips;
1167
1168        /*
1169         * Collect everything we know they would have at the end of
1170         * this push, and collect all tags they have.
1171         */
1172        memset(&sent_tips, 0, sizeof(sent_tips));
1173        for (ref = *dst; ref; ref = ref->next) {
1174                if (ref->peer_ref &&
1175                    !is_null_oid(&ref->peer_ref->new_oid))
1176                        add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1177                else
1178                        add_to_tips(&sent_tips, &ref->old_oid);
1179                if (starts_with(ref->name, "refs/tags/"))
1180                        string_list_append(&dst_tag, ref->name);
1181        }
1182        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1183
1184        string_list_sort(&dst_tag);
1185
1186        /* Collect tags they do not have. */
1187        for (ref = src; ref; ref = ref->next) {
1188                if (!starts_with(ref->name, "refs/tags/"))
1189                        continue; /* not a tag */
1190                if (string_list_has_string(&dst_tag, ref->name))
1191                        continue; /* they already have it */
1192                if (oid_object_info(the_repository, &ref->new_oid, NULL) != OBJ_TAG)
1193                        continue; /* be conservative */
1194                item = string_list_append(&src_tag, ref->name);
1195                item->util = ref;
1196        }
1197        string_list_clear(&dst_tag, 0);
1198
1199        /*
1200         * At this point, src_tag lists tags that are missing from
1201         * dst, and sent_tips lists the tips we are pushing or those
1202         * that we know they already have. An element in the src_tag
1203         * that is an ancestor of any of the sent_tips needs to be
1204         * sent to the other side.
1205         */
1206        if (sent_tips.nr) {
1207                for_each_string_list_item(item, &src_tag) {
1208                        struct ref *ref = item->util;
1209                        struct ref *dst_ref;
1210                        struct commit *commit;
1211
1212                        if (is_null_oid(&ref->new_oid))
1213                                continue;
1214                        commit = lookup_commit_reference_gently(the_repository,
1215                                                                &ref->new_oid,
1216                                                                1);
1217                        if (!commit)
1218                                /* not pushing a commit, which is not an error */
1219                                continue;
1220
1221                        /*
1222                         * Is this tag, which they do not have, reachable from
1223                         * any of the commits we are sending?
1224                         */
1225                        if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1226                                continue;
1227
1228                        /* Add it in */
1229                        dst_ref = make_linked_ref(ref->name, dst_tail);
1230                        oidcpy(&dst_ref->new_oid, &ref->new_oid);
1231                        dst_ref->peer_ref = copy_ref(ref);
1232                }
1233        }
1234        string_list_clear(&src_tag, 0);
1235        free(sent_tips.tip);
1236}
1237
1238struct ref *find_ref_by_name(const struct ref *list, const char *name)
1239{
1240        for ( ; list; list = list->next)
1241                if (!strcmp(list->name, name))
1242                        return (struct ref *)list;
1243        return NULL;
1244}
1245
1246static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1247{
1248        for ( ; ref; ref = ref->next)
1249                string_list_append_nodup(ref_index, ref->name)->util = ref;
1250
1251        string_list_sort(ref_index);
1252}
1253
1254/*
1255 * Given only the set of local refs, sanity-check the set of push
1256 * refspecs. We can't catch all errors that match_push_refs would,
1257 * but we can catch some errors early before even talking to the
1258 * remote side.
1259 */
1260int check_push_refs(struct ref *src, struct refspec *rs)
1261{
1262        int ret = 0;
1263        int i;
1264
1265        for (i = 0; i < rs->nr; i++) {
1266                struct refspec_item *item = &rs->items[i];
1267
1268                if (item->pattern || item->matching)
1269                        continue;
1270
1271                ret |= match_explicit_lhs(src, item, NULL, NULL);
1272        }
1273
1274        return ret;
1275}
1276
1277/*
1278 * Given the set of refs the local repository has, the set of refs the
1279 * remote repository has, and the refspec used for push, determine
1280 * what remote refs we will update and with what value by setting
1281 * peer_ref (which object is being pushed) and force (if the push is
1282 * forced) in elements of "dst". The function may add new elements to
1283 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1284 */
1285int match_push_refs(struct ref *src, struct ref **dst,
1286                    struct refspec *rs, int flags)
1287{
1288        int send_all = flags & MATCH_REFS_ALL;
1289        int send_mirror = flags & MATCH_REFS_MIRROR;
1290        int send_prune = flags & MATCH_REFS_PRUNE;
1291        int errs;
1292        struct ref *ref, **dst_tail = tail_ref(dst);
1293        struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1294
1295        /* If no refspec is provided, use the default ":" */
1296        if (!rs->nr)
1297                refspec_append(rs, ":");
1298
1299        errs = match_explicit_refs(src, *dst, &dst_tail, rs);
1300
1301        /* pick the remainder */
1302        for (ref = src; ref; ref = ref->next) {
1303                struct string_list_item *dst_item;
1304                struct ref *dst_peer;
1305                const struct refspec_item *pat = NULL;
1306                char *dst_name;
1307
1308                dst_name = get_ref_match(rs, ref, send_mirror, FROM_SRC, &pat);
1309                if (!dst_name)
1310                        continue;
1311
1312                if (!dst_ref_index.nr)
1313                        prepare_ref_index(&dst_ref_index, *dst);
1314
1315                dst_item = string_list_lookup(&dst_ref_index, dst_name);
1316                dst_peer = dst_item ? dst_item->util : NULL;
1317                if (dst_peer) {
1318                        if (dst_peer->peer_ref)
1319                                /* We're already sending something to this ref. */
1320                                goto free_name;
1321                } else {
1322                        if (pat->matching && !(send_all || send_mirror))
1323                                /*
1324                                 * Remote doesn't have it, and we have no
1325                                 * explicit pattern, and we don't have
1326                                 * --all or --mirror.
1327                                 */
1328                                goto free_name;
1329
1330                        /* Create a new one and link it */
1331                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1332                        oidcpy(&dst_peer->new_oid, &ref->new_oid);
1333                        string_list_insert(&dst_ref_index,
1334                                dst_peer->name)->util = dst_peer;
1335                }
1336                dst_peer->peer_ref = copy_ref(ref);
1337                dst_peer->force = pat->force;
1338        free_name:
1339                free(dst_name);
1340        }
1341
1342        string_list_clear(&dst_ref_index, 0);
1343
1344        if (flags & MATCH_REFS_FOLLOW_TAGS)
1345                add_missing_tags(src, dst, &dst_tail);
1346
1347        if (send_prune) {
1348                struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1349                /* check for missing refs on the remote */
1350                for (ref = *dst; ref; ref = ref->next) {
1351                        char *src_name;
1352
1353                        if (ref->peer_ref)
1354                                /* We're already sending something to this ref. */
1355                                continue;
1356
1357                        src_name = get_ref_match(rs, ref, send_mirror, FROM_DST, NULL);
1358                        if (src_name) {
1359                                if (!src_ref_index.nr)
1360                                        prepare_ref_index(&src_ref_index, src);
1361                                if (!string_list_has_string(&src_ref_index,
1362                                            src_name))
1363                                        ref->peer_ref = alloc_delete_ref();
1364                                free(src_name);
1365                        }
1366                }
1367                string_list_clear(&src_ref_index, 0);
1368        }
1369
1370        if (errs)
1371                return -1;
1372        return 0;
1373}
1374
1375void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1376                             int force_update)
1377{
1378        struct ref *ref;
1379
1380        for (ref = remote_refs; ref; ref = ref->next) {
1381                int force_ref_update = ref->force || force_update;
1382                int reject_reason = 0;
1383
1384                if (ref->peer_ref)
1385                        oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1386                else if (!send_mirror)
1387                        continue;
1388
1389                ref->deletion = is_null_oid(&ref->new_oid);
1390                if (!ref->deletion &&
1391                        !oidcmp(&ref->old_oid, &ref->new_oid)) {
1392                        ref->status = REF_STATUS_UPTODATE;
1393                        continue;
1394                }
1395
1396                /*
1397                 * If the remote ref has moved and is now different
1398                 * from what we expect, reject any push.
1399                 *
1400                 * It also is an error if the user told us to check
1401                 * with the remote-tracking branch to find the value
1402                 * to expect, but we did not have such a tracking
1403                 * branch.
1404                 */
1405                if (ref->expect_old_sha1) {
1406                        if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
1407                                reject_reason = REF_STATUS_REJECT_STALE;
1408                        else
1409                                /* If the ref isn't stale then force the update. */
1410                                force_ref_update = 1;
1411                }
1412
1413                /*
1414                 * If the update isn't already rejected then check
1415                 * the usual "must fast-forward" rules.
1416                 *
1417                 * Decide whether an individual refspec A:B can be
1418                 * pushed.  The push will succeed if any of the
1419                 * following are true:
1420                 *
1421                 * (1) the remote reference B does not exist
1422                 *
1423                 * (2) the remote reference B is being removed (i.e.,
1424                 *     pushing :B where no source is specified)
1425                 *
1426                 * (3) the destination is not under refs/tags/, and
1427                 *     if the old and new value is a commit, the new
1428                 *     is a descendant of the old.
1429                 *
1430                 * (4) it is forced using the +A:B notation, or by
1431                 *     passing the --force argument
1432                 */
1433
1434                if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1435                        if (starts_with(ref->name, "refs/tags/"))
1436                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1437                        else if (!has_object_file(&ref->old_oid))
1438                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1439                        else if (!lookup_commit_reference_gently(the_repository, &ref->old_oid, 1) ||
1440                                 !lookup_commit_reference_gently(the_repository, &ref->new_oid, 1))
1441                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1442                        else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1443                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1444                }
1445
1446                /*
1447                 * "--force" will defeat any rejection implemented
1448                 * by the rules above.
1449                 */
1450                if (!force_ref_update)
1451                        ref->status = reject_reason;
1452                else if (reject_reason)
1453                        ref->forced_update = 1;
1454        }
1455}
1456
1457static void set_merge(struct branch *ret)
1458{
1459        struct remote *remote;
1460        char *ref;
1461        struct object_id oid;
1462        int i;
1463
1464        if (!ret)
1465                return; /* no branch */
1466        if (ret->merge)
1467                return; /* already run */
1468        if (!ret->remote_name || !ret->merge_nr) {
1469                /*
1470                 * no merge config; let's make sure we don't confuse callers
1471                 * with a non-zero merge_nr but a NULL merge
1472                 */
1473                ret->merge_nr = 0;
1474                return;
1475        }
1476
1477        remote = remote_get(ret->remote_name);
1478
1479        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1480        for (i = 0; i < ret->merge_nr; i++) {
1481                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1482                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1483                if (!remote_find_tracking(remote, ret->merge[i]) ||
1484                    strcmp(ret->remote_name, "."))
1485                        continue;
1486                if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1487                             &oid, &ref) == 1)
1488                        ret->merge[i]->dst = ref;
1489                else
1490                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1491        }
1492}
1493
1494struct branch *branch_get(const char *name)
1495{
1496        struct branch *ret;
1497
1498        read_config();
1499        if (!name || !*name || !strcmp(name, "HEAD"))
1500                ret = current_branch;
1501        else
1502                ret = make_branch(name, 0);
1503        set_merge(ret);
1504        return ret;
1505}
1506
1507int branch_has_merge_config(struct branch *branch)
1508{
1509        return branch && !!branch->merge;
1510}
1511
1512int branch_merge_matches(struct branch *branch,
1513                                 int i,
1514                                 const char *refname)
1515{
1516        if (!branch || i < 0 || i >= branch->merge_nr)
1517                return 0;
1518        return refname_match(branch->merge[i]->src, refname);
1519}
1520
1521__attribute__((format (printf,2,3)))
1522static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1523{
1524        if (err) {
1525                va_list ap;
1526                va_start(ap, fmt);
1527                strbuf_vaddf(err, fmt, ap);
1528                va_end(ap);
1529        }
1530        return NULL;
1531}
1532
1533const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1534{
1535        if (!branch)
1536                return error_buf(err, _("HEAD does not point to a branch"));
1537
1538        if (!branch->merge || !branch->merge[0]) {
1539                /*
1540                 * no merge config; is it because the user didn't define any,
1541                 * or because it is not a real branch, and get_branch
1542                 * auto-vivified it?
1543                 */
1544                if (!ref_exists(branch->refname))
1545                        return error_buf(err, _("no such branch: '%s'"),
1546                                         branch->name);
1547                return error_buf(err,
1548                                 _("no upstream configured for branch '%s'"),
1549                                 branch->name);
1550        }
1551
1552        if (!branch->merge[0]->dst)
1553                return error_buf(err,
1554                                 _("upstream branch '%s' not stored as a remote-tracking branch"),
1555                                 branch->merge[0]->src);
1556
1557        return branch->merge[0]->dst;
1558}
1559
1560static const char *tracking_for_push_dest(struct remote *remote,
1561                                          const char *refname,
1562                                          struct strbuf *err)
1563{
1564        char *ret;
1565
1566        ret = apply_refspecs(&remote->fetch, refname);
1567        if (!ret)
1568                return error_buf(err,
1569                                 _("push destination '%s' on remote '%s' has no local tracking branch"),
1570                                 refname, remote->name);
1571        return ret;
1572}
1573
1574static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1575{
1576        struct remote *remote;
1577
1578        remote = remote_get(pushremote_for_branch(branch, NULL));
1579        if (!remote)
1580                return error_buf(err,
1581                                 _("branch '%s' has no remote for pushing"),
1582                                 branch->name);
1583
1584        if (remote->push.nr) {
1585                char *dst;
1586                const char *ret;
1587
1588                dst = apply_refspecs(&remote->push, branch->refname);
1589                if (!dst)
1590                        return error_buf(err,
1591                                         _("push refspecs for '%s' do not include '%s'"),
1592                                         remote->name, branch->name);
1593
1594                ret = tracking_for_push_dest(remote, dst, err);
1595                free(dst);
1596                return ret;
1597        }
1598
1599        if (remote->mirror)
1600                return tracking_for_push_dest(remote, branch->refname, err);
1601
1602        switch (push_default) {
1603        case PUSH_DEFAULT_NOTHING:
1604                return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1605
1606        case PUSH_DEFAULT_MATCHING:
1607        case PUSH_DEFAULT_CURRENT:
1608                return tracking_for_push_dest(remote, branch->refname, err);
1609
1610        case PUSH_DEFAULT_UPSTREAM:
1611                return branch_get_upstream(branch, err);
1612
1613        case PUSH_DEFAULT_UNSPECIFIED:
1614        case PUSH_DEFAULT_SIMPLE:
1615                {
1616                        const char *up, *cur;
1617
1618                        up = branch_get_upstream(branch, err);
1619                        if (!up)
1620                                return NULL;
1621                        cur = tracking_for_push_dest(remote, branch->refname, err);
1622                        if (!cur)
1623                                return NULL;
1624                        if (strcmp(cur, up))
1625                                return error_buf(err,
1626                                                 _("cannot resolve 'simple' push to a single destination"));
1627                        return cur;
1628                }
1629        }
1630
1631        BUG("unhandled push situation");
1632}
1633
1634const char *branch_get_push(struct branch *branch, struct strbuf *err)
1635{
1636        if (!branch)
1637                return error_buf(err, _("HEAD does not point to a branch"));
1638
1639        if (!branch->push_tracking_ref)
1640                branch->push_tracking_ref = branch_get_push_1(branch, err);
1641        return branch->push_tracking_ref;
1642}
1643
1644static int ignore_symref_update(const char *refname)
1645{
1646        int flag;
1647
1648        if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
1649                return 0; /* non-existing refs are OK */
1650        return (flag & REF_ISSYMREF);
1651}
1652
1653/*
1654 * Create and return a list of (struct ref) consisting of copies of
1655 * each remote_ref that matches refspec.  refspec must be a pattern.
1656 * Fill in the copies' peer_ref to describe the local tracking refs to
1657 * which they map.  Omit any references that would map to an existing
1658 * local symbolic ref.
1659 */
1660static struct ref *get_expanded_map(const struct ref *remote_refs,
1661                                    const struct refspec_item *refspec)
1662{
1663        const struct ref *ref;
1664        struct ref *ret = NULL;
1665        struct ref **tail = &ret;
1666
1667        for (ref = remote_refs; ref; ref = ref->next) {
1668                char *expn_name = NULL;
1669
1670                if (strchr(ref->name, '^'))
1671                        continue; /* a dereference item */
1672                if (match_name_with_pattern(refspec->src, ref->name,
1673                                            refspec->dst, &expn_name) &&
1674                    !ignore_symref_update(expn_name)) {
1675                        struct ref *cpy = copy_ref(ref);
1676
1677                        cpy->peer_ref = alloc_ref(expn_name);
1678                        if (refspec->force)
1679                                cpy->peer_ref->force = 1;
1680                        *tail = cpy;
1681                        tail = &cpy->next;
1682                }
1683                free(expn_name);
1684        }
1685
1686        return ret;
1687}
1688
1689static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1690{
1691        const struct ref *ref;
1692        for (ref = refs; ref; ref = ref->next) {
1693                if (refname_match(name, ref->name))
1694                        return ref;
1695        }
1696        return NULL;
1697}
1698
1699struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1700{
1701        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1702
1703        if (!ref)
1704                return NULL;
1705
1706        return copy_ref(ref);
1707}
1708
1709static struct ref *get_local_ref(const char *name)
1710{
1711        if (!name || name[0] == '\0')
1712                return NULL;
1713
1714        if (starts_with(name, "refs/"))
1715                return alloc_ref(name);
1716
1717        if (starts_with(name, "heads/") ||
1718            starts_with(name, "tags/") ||
1719            starts_with(name, "remotes/"))
1720                return alloc_ref_with_prefix("refs/", 5, name);
1721
1722        return alloc_ref_with_prefix("refs/heads/", 11, name);
1723}
1724
1725int get_fetch_map(const struct ref *remote_refs,
1726                  const struct refspec_item *refspec,
1727                  struct ref ***tail,
1728                  int missing_ok)
1729{
1730        struct ref *ref_map, **rmp;
1731
1732        if (refspec->pattern) {
1733                ref_map = get_expanded_map(remote_refs, refspec);
1734        } else {
1735                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1736
1737                if (refspec->exact_sha1) {
1738                        ref_map = alloc_ref(name);
1739                        get_oid_hex(name, &ref_map->old_oid);
1740                        ref_map->exact_oid = 1;
1741                } else {
1742                        ref_map = get_remote_ref(remote_refs, name);
1743                }
1744                if (!missing_ok && !ref_map)
1745                        die("Couldn't find remote ref %s", name);
1746                if (ref_map) {
1747                        ref_map->peer_ref = get_local_ref(refspec->dst);
1748                        if (ref_map->peer_ref && refspec->force)
1749                                ref_map->peer_ref->force = 1;
1750                }
1751        }
1752
1753        for (rmp = &ref_map; *rmp; ) {
1754                if ((*rmp)->peer_ref) {
1755                        if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1756                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1757                                struct ref *ignore = *rmp;
1758                                error("* Ignoring funny ref '%s' locally",
1759                                      (*rmp)->peer_ref->name);
1760                                *rmp = (*rmp)->next;
1761                                free(ignore->peer_ref);
1762                                free(ignore);
1763                                continue;
1764                        }
1765                }
1766                rmp = &((*rmp)->next);
1767        }
1768
1769        if (ref_map)
1770                tail_link_ref(ref_map, tail);
1771
1772        return 0;
1773}
1774
1775int resolve_remote_symref(struct ref *ref, struct ref *list)
1776{
1777        if (!ref->symref)
1778                return 0;
1779        for (; list; list = list->next)
1780                if (!strcmp(ref->symref, list->name)) {
1781                        oidcpy(&ref->old_oid, &list->old_oid);
1782                        return 0;
1783                }
1784        return 1;
1785}
1786
1787static void unmark_and_free(struct commit_list *list, unsigned int mark)
1788{
1789        while (list) {
1790                struct commit *commit = pop_commit(&list);
1791                commit->object.flags &= ~mark;
1792        }
1793}
1794
1795int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1796{
1797        struct object *o;
1798        struct commit *old_commit, *new_commit;
1799        struct commit_list *list, *used;
1800        int found = 0;
1801
1802        /*
1803         * Both new_commit and old_commit must be commit-ish and new_commit is descendant of
1804         * old_commit.  Otherwise we require --force.
1805         */
1806        o = deref_tag(the_repository, parse_object(the_repository, old_oid),
1807                      NULL, 0);
1808        if (!o || o->type != OBJ_COMMIT)
1809                return 0;
1810        old_commit = (struct commit *) o;
1811
1812        o = deref_tag(the_repository, parse_object(the_repository, new_oid),
1813                      NULL, 0);
1814        if (!o || o->type != OBJ_COMMIT)
1815                return 0;
1816        new_commit = (struct commit *) o;
1817
1818        if (parse_commit(new_commit) < 0)
1819                return 0;
1820
1821        used = list = NULL;
1822        commit_list_insert(new_commit, &list);
1823        while (list) {
1824                new_commit = pop_most_recent_commit(&list, TMP_MARK);
1825                commit_list_insert(new_commit, &used);
1826                if (new_commit == old_commit) {
1827                        found = 1;
1828                        break;
1829                }
1830        }
1831        unmark_and_free(list, TMP_MARK);
1832        unmark_and_free(used, TMP_MARK);
1833        return found;
1834}
1835
1836/*
1837 * Lookup the upstream branch for the given branch and if present, optionally
1838 * compute the commit ahead/behind values for the pair.
1839 *
1840 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
1841 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
1842 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
1843 * set to zero).
1844 *
1845 * The name of the upstream branch (or NULL if no upstream is defined) is
1846 * returned via *upstream_name, if it is not itself NULL.
1847 *
1848 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1849 * upstream defined, or ref does not exist).  Returns 0 if the commits are
1850 * identical.  Returns 1 if commits are different.
1851 */
1852int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1853                       const char **upstream_name, enum ahead_behind_flags abf)
1854{
1855        struct object_id oid;
1856        struct commit *ours, *theirs;
1857        struct rev_info revs;
1858        const char *base;
1859        struct argv_array argv = ARGV_ARRAY_INIT;
1860
1861        /* Cannot stat unless we are marked to build on top of somebody else. */
1862        base = branch_get_upstream(branch, NULL);
1863        if (upstream_name)
1864                *upstream_name = base;
1865        if (!base)
1866                return -1;
1867
1868        /* Cannot stat if what we used to build on no longer exists */
1869        if (read_ref(base, &oid))
1870                return -1;
1871        theirs = lookup_commit_reference(the_repository, &oid);
1872        if (!theirs)
1873                return -1;
1874
1875        if (read_ref(branch->refname, &oid))
1876                return -1;
1877        ours = lookup_commit_reference(the_repository, &oid);
1878        if (!ours)
1879                return -1;
1880
1881        *num_theirs = *num_ours = 0;
1882
1883        /* are we the same? */
1884        if (theirs == ours)
1885                return 0;
1886        if (abf == AHEAD_BEHIND_QUICK)
1887                return 1;
1888        if (abf != AHEAD_BEHIND_FULL)
1889                BUG("stat_tracking_info: invalid abf '%d'", abf);
1890
1891        /* Run "rev-list --left-right ours...theirs" internally... */
1892        argv_array_push(&argv, ""); /* ignored */
1893        argv_array_push(&argv, "--left-right");
1894        argv_array_pushf(&argv, "%s...%s",
1895                         oid_to_hex(&ours->object.oid),
1896                         oid_to_hex(&theirs->object.oid));
1897        argv_array_push(&argv, "--");
1898
1899        init_revisions(&revs, NULL);
1900        setup_revisions(argv.argc, argv.argv, &revs, NULL);
1901        if (prepare_revision_walk(&revs))
1902                die("revision walk setup failed");
1903
1904        /* ... and count the commits on each side. */
1905        while (1) {
1906                struct commit *c = get_revision(&revs);
1907                if (!c)
1908                        break;
1909                if (c->object.flags & SYMMETRIC_LEFT)
1910                        (*num_ours)++;
1911                else
1912                        (*num_theirs)++;
1913        }
1914
1915        /* clear object flags smudged by the above traversal */
1916        clear_commit_marks(ours, ALL_REV_FLAGS);
1917        clear_commit_marks(theirs, ALL_REV_FLAGS);
1918
1919        argv_array_clear(&argv);
1920        return 1;
1921}
1922
1923/*
1924 * Return true when there is anything to report, otherwise false.
1925 */
1926int format_tracking_info(struct branch *branch, struct strbuf *sb,
1927                         enum ahead_behind_flags abf)
1928{
1929        int ours, theirs, sti;
1930        const char *full_base;
1931        char *base;
1932        int upstream_is_gone = 0;
1933
1934        sti = stat_tracking_info(branch, &ours, &theirs, &full_base, abf);
1935        if (sti < 0) {
1936                if (!full_base)
1937                        return 0;
1938                upstream_is_gone = 1;
1939        }
1940
1941        base = shorten_unambiguous_ref(full_base, 0);
1942        if (upstream_is_gone) {
1943                strbuf_addf(sb,
1944                        _("Your branch is based on '%s', but the upstream is gone.\n"),
1945                        base);
1946                if (advice_status_hints)
1947                        strbuf_addstr(sb,
1948                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1949        } else if (!sti) {
1950                strbuf_addf(sb,
1951                        _("Your branch is up to date with '%s'.\n"),
1952                        base);
1953        } else if (abf == AHEAD_BEHIND_QUICK) {
1954                strbuf_addf(sb,
1955                            _("Your branch and '%s' refer to different commits.\n"),
1956                            base);
1957                if (advice_status_hints)
1958                        strbuf_addf(sb, _("  (use \"%s\" for details)\n"),
1959                                    "git status --ahead-behind");
1960        } else if (!theirs) {
1961                strbuf_addf(sb,
1962                        Q_("Your branch is ahead of '%s' by %d commit.\n",
1963                           "Your branch is ahead of '%s' by %d commits.\n",
1964                           ours),
1965                        base, ours);
1966                if (advice_status_hints)
1967                        strbuf_addstr(sb,
1968                                _("  (use \"git push\" to publish your local commits)\n"));
1969        } else if (!ours) {
1970                strbuf_addf(sb,
1971                        Q_("Your branch is behind '%s' by %d commit, "
1972                               "and can be fast-forwarded.\n",
1973                           "Your branch is behind '%s' by %d commits, "
1974                               "and can be fast-forwarded.\n",
1975                           theirs),
1976                        base, theirs);
1977                if (advice_status_hints)
1978                        strbuf_addstr(sb,
1979                                _("  (use \"git pull\" to update your local branch)\n"));
1980        } else {
1981                strbuf_addf(sb,
1982                        Q_("Your branch and '%s' have diverged,\n"
1983                               "and have %d and %d different commit each, "
1984                               "respectively.\n",
1985                           "Your branch and '%s' have diverged,\n"
1986                               "and have %d and %d different commits each, "
1987                               "respectively.\n",
1988                           ours + theirs),
1989                        base, ours, theirs);
1990                if (advice_status_hints)
1991                        strbuf_addstr(sb,
1992                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1993        }
1994        free(base);
1995        return 1;
1996}
1997
1998static int one_local_ref(const char *refname, const struct object_id *oid,
1999                         int flag, void *cb_data)
2000{
2001        struct ref ***local_tail = cb_data;
2002        struct ref *ref;
2003
2004        /* we already know it starts with refs/ to get here */
2005        if (check_refname_format(refname + 5, 0))
2006                return 0;
2007
2008        ref = alloc_ref(refname);
2009        oidcpy(&ref->new_oid, oid);
2010        **local_tail = ref;
2011        *local_tail = &ref->next;
2012        return 0;
2013}
2014
2015struct ref *get_local_heads(void)
2016{
2017        struct ref *local_refs = NULL, **local_tail = &local_refs;
2018
2019        for_each_ref(one_local_ref, &local_tail);
2020        return local_refs;
2021}
2022
2023struct ref *guess_remote_head(const struct ref *head,
2024                              const struct ref *refs,
2025                              int all)
2026{
2027        const struct ref *r;
2028        struct ref *list = NULL;
2029        struct ref **tail = &list;
2030
2031        if (!head)
2032                return NULL;
2033
2034        /*
2035         * Some transports support directly peeking at
2036         * where HEAD points; if that is the case, then
2037         * we don't have to guess.
2038         */
2039        if (head->symref)
2040                return copy_ref(find_ref_by_name(refs, head->symref));
2041
2042        /* If refs/heads/master could be right, it is. */
2043        if (!all) {
2044                r = find_ref_by_name(refs, "refs/heads/master");
2045                if (r && !oidcmp(&r->old_oid, &head->old_oid))
2046                        return copy_ref(r);
2047        }
2048
2049        /* Look for another ref that points there */
2050        for (r = refs; r; r = r->next) {
2051                if (r != head &&
2052                    starts_with(r->name, "refs/heads/") &&
2053                    !oidcmp(&r->old_oid, &head->old_oid)) {
2054                        *tail = copy_ref(r);
2055                        tail = &((*tail)->next);
2056                        if (!all)
2057                                break;
2058                }
2059        }
2060
2061        return list;
2062}
2063
2064struct stale_heads_info {
2065        struct string_list *ref_names;
2066        struct ref **stale_refs_tail;
2067        struct refspec *rs;
2068};
2069
2070static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2071                              int flags, void *cb_data)
2072{
2073        struct stale_heads_info *info = cb_data;
2074        struct string_list matches = STRING_LIST_INIT_DUP;
2075        struct refspec_item query;
2076        int i, stale = 1;
2077        memset(&query, 0, sizeof(struct refspec_item));
2078        query.dst = (char *)refname;
2079
2080        query_refspecs_multiple(info->rs, &query, &matches);
2081        if (matches.nr == 0)
2082                goto clean_exit; /* No matches */
2083
2084        /*
2085         * If we did find a suitable refspec and it's not a symref and
2086         * it's not in the list of refs that currently exist in that
2087         * remote, we consider it to be stale. In order to deal with
2088         * overlapping refspecs, we need to go over all of the
2089         * matching refs.
2090         */
2091        if (flags & REF_ISSYMREF)
2092                goto clean_exit;
2093
2094        for (i = 0; stale && i < matches.nr; i++)
2095                if (string_list_has_string(info->ref_names, matches.items[i].string))
2096                        stale = 0;
2097
2098        if (stale) {
2099                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2100                oidcpy(&ref->new_oid, oid);
2101        }
2102
2103clean_exit:
2104        string_list_clear(&matches, 0);
2105        return 0;
2106}
2107
2108struct ref *get_stale_heads(struct refspec *rs, struct ref *fetch_map)
2109{
2110        struct ref *ref, *stale_refs = NULL;
2111        struct string_list ref_names = STRING_LIST_INIT_NODUP;
2112        struct stale_heads_info info;
2113
2114        info.ref_names = &ref_names;
2115        info.stale_refs_tail = &stale_refs;
2116        info.rs = rs;
2117        for (ref = fetch_map; ref; ref = ref->next)
2118                string_list_append(&ref_names, ref->name);
2119        string_list_sort(&ref_names);
2120        for_each_ref(get_stale_heads_cb, &info);
2121        string_list_clear(&ref_names, 0);
2122        return stale_refs;
2123}
2124
2125/*
2126 * Compare-and-swap
2127 */
2128static void clear_cas_option(struct push_cas_option *cas)
2129{
2130        int i;
2131
2132        for (i = 0; i < cas->nr; i++)
2133                free(cas->entry[i].refname);
2134        free(cas->entry);
2135        memset(cas, 0, sizeof(*cas));
2136}
2137
2138static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2139                                      const char *refname,
2140                                      size_t refnamelen)
2141{
2142        struct push_cas *entry;
2143        ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2144        entry = &cas->entry[cas->nr++];
2145        memset(entry, 0, sizeof(*entry));
2146        entry->refname = xmemdupz(refname, refnamelen);
2147        return entry;
2148}
2149
2150static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2151{
2152        const char *colon;
2153        struct push_cas *entry;
2154
2155        if (unset) {
2156                /* "--no-<option>" */
2157                clear_cas_option(cas);
2158                return 0;
2159        }
2160
2161        if (!arg) {
2162                /* just "--<option>" */
2163                cas->use_tracking_for_rest = 1;
2164                return 0;
2165        }
2166
2167        /* "--<option>=refname" or "--<option>=refname:value" */
2168        colon = strchrnul(arg, ':');
2169        entry = add_cas_entry(cas, arg, colon - arg);
2170        if (!*colon)
2171                entry->use_tracking = 1;
2172        else if (!colon[1])
2173                oidclr(&entry->expect);
2174        else if (get_oid(colon + 1, &entry->expect))
2175                return error("cannot parse expected object name '%s'", colon + 1);
2176        return 0;
2177}
2178
2179int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2180{
2181        return parse_push_cas_option(opt->value, arg, unset);
2182}
2183
2184int is_empty_cas(const struct push_cas_option *cas)
2185{
2186        return !cas->use_tracking_for_rest && !cas->nr;
2187}
2188
2189/*
2190 * Look at remote.fetch refspec and see if we have a remote
2191 * tracking branch for the refname there.  Fill its current
2192 * value in sha1[].
2193 * If we cannot do so, return negative to signal an error.
2194 */
2195static int remote_tracking(struct remote *remote, const char *refname,
2196                           struct object_id *oid)
2197{
2198        char *dst;
2199
2200        dst = apply_refspecs(&remote->fetch, refname);
2201        if (!dst)
2202                return -1; /* no tracking ref for refname at remote */
2203        if (read_ref(dst, oid))
2204                return -1; /* we know what the tracking ref is but we cannot read it */
2205        return 0;
2206}
2207
2208static void apply_cas(struct push_cas_option *cas,
2209                      struct remote *remote,
2210                      struct ref *ref)
2211{
2212        int i;
2213
2214        /* Find an explicit --<option>=<name>[:<value>] entry */
2215        for (i = 0; i < cas->nr; i++) {
2216                struct push_cas *entry = &cas->entry[i];
2217                if (!refname_match(entry->refname, ref->name))
2218                        continue;
2219                ref->expect_old_sha1 = 1;
2220                if (!entry->use_tracking)
2221                        oidcpy(&ref->old_oid_expect, &entry->expect);
2222                else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2223                        oidclr(&ref->old_oid_expect);
2224                return;
2225        }
2226
2227        /* Are we using "--<option>" to cover all? */
2228        if (!cas->use_tracking_for_rest)
2229                return;
2230
2231        ref->expect_old_sha1 = 1;
2232        if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2233                oidclr(&ref->old_oid_expect);
2234}
2235
2236void apply_push_cas(struct push_cas_option *cas,
2237                    struct remote *remote,
2238                    struct ref *remote_refs)
2239{
2240        struct ref *ref;
2241        for (ref = remote_refs; ref; ref = ref->next)
2242                apply_cas(cas, remote, ref);
2243}