Andrew's git / gitweb.git / remote.c
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remote.con commit add: lift the pathspec magic restriction on "add -p" (625c330)
   1#include "cache.h"
   2#include "remote.h"
   3#include "refs.h"
   4#include "commit.h"
   5#include "diff.h"
   6#include "revision.h"
   7#include "dir.h"
   8#include "tag.h"
   9#include "string-list.h"
  10#include "mergesort.h"
  11
  12enum map_direction { FROM_SRC, FROM_DST };
  13
  14static struct refspec s_tag_refspec = {
  15        0,
  16        1,
  17        0,
  18        0,
  19        "refs/tags/*",
  20        "refs/tags/*"
  21};
  22
  23const struct refspec *tag_refspec = &s_tag_refspec;
  24
  25struct counted_string {
  26        size_t len;
  27        const char *s;
  28};
  29struct rewrite {
  30        const char *base;
  31        size_t baselen;
  32        struct counted_string *instead_of;
  33        int instead_of_nr;
  34        int instead_of_alloc;
  35};
  36struct rewrites {
  37        struct rewrite **rewrite;
  38        int rewrite_alloc;
  39        int rewrite_nr;
  40};
  41
  42static struct remote **remotes;
  43static int remotes_alloc;
  44static int remotes_nr;
  45
  46static struct branch **branches;
  47static int branches_alloc;
  48static int branches_nr;
  49
  50static struct branch *current_branch;
  51static const char *default_remote_name;
  52static const char *pushremote_name;
  53static int explicit_default_remote_name;
  54
  55static struct rewrites rewrites;
  56static struct rewrites rewrites_push;
  57
  58#define BUF_SIZE (2048)
  59static char buffer[BUF_SIZE];
  60
  61static int valid_remote(const struct remote *remote)
  62{
  63        return (!!remote->url) || (!!remote->foreign_vcs);
  64}
  65
  66static const char *alias_url(const char *url, struct rewrites *r)
  67{
  68        int i, j;
  69        char *ret;
  70        struct counted_string *longest;
  71        int longest_i;
  72
  73        longest = NULL;
  74        longest_i = -1;
  75        for (i = 0; i < r->rewrite_nr; i++) {
  76                if (!r->rewrite[i])
  77                        continue;
  78                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  79                        if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  80                            (!longest ||
  81                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  82                                longest = &(r->rewrite[i]->instead_of[j]);
  83                                longest_i = i;
  84                        }
  85                }
  86        }
  87        if (!longest)
  88                return url;
  89
  90        ret = xmalloc(r->rewrite[longest_i]->baselen +
  91                     (strlen(url) - longest->len) + 1);
  92        strcpy(ret, r->rewrite[longest_i]->base);
  93        strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  94        return ret;
  95}
  96
  97static void add_push_refspec(struct remote *remote, const char *ref)
  98{
  99        ALLOC_GROW(remote->push_refspec,
 100                   remote->push_refspec_nr + 1,
 101                   remote->push_refspec_alloc);
 102        remote->push_refspec[remote->push_refspec_nr++] = ref;
 103}
 104
 105static void add_fetch_refspec(struct remote *remote, const char *ref)
 106{
 107        ALLOC_GROW(remote->fetch_refspec,
 108                   remote->fetch_refspec_nr + 1,
 109                   remote->fetch_refspec_alloc);
 110        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 111}
 112
 113static void add_url(struct remote *remote, const char *url)
 114{
 115        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 116        remote->url[remote->url_nr++] = url;
 117}
 118
 119static void add_pushurl(struct remote *remote, const char *pushurl)
 120{
 121        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 122        remote->pushurl[remote->pushurl_nr++] = pushurl;
 123}
 124
 125static void add_pushurl_alias(struct remote *remote, const char *url)
 126{
 127        const char *pushurl = alias_url(url, &rewrites_push);
 128        if (pushurl != url)
 129                add_pushurl(remote, pushurl);
 130}
 131
 132static void add_url_alias(struct remote *remote, const char *url)
 133{
 134        add_url(remote, alias_url(url, &rewrites));
 135        add_pushurl_alias(remote, url);
 136}
 137
 138static struct remote *make_remote(const char *name, int len)
 139{
 140        struct remote *ret;
 141        int i;
 142
 143        for (i = 0; i < remotes_nr; i++) {
 144                if (len ? (!strncmp(name, remotes[i]->name, len) &&
 145                           !remotes[i]->name[len]) :
 146                    !strcmp(name, remotes[i]->name))
 147                        return remotes[i];
 148        }
 149
 150        ret = xcalloc(1, sizeof(struct remote));
 151        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 152        remotes[remotes_nr++] = ret;
 153        if (len)
 154                ret->name = xstrndup(name, len);
 155        else
 156                ret->name = xstrdup(name);
 157        return ret;
 158}
 159
 160static void add_merge(struct branch *branch, const char *name)
 161{
 162        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 163                   branch->merge_alloc);
 164        branch->merge_name[branch->merge_nr++] = name;
 165}
 166
 167static struct branch *make_branch(const char *name, int len)
 168{
 169        struct branch *ret;
 170        int i;
 171        char *refname;
 172
 173        for (i = 0; i < branches_nr; i++) {
 174                if (len ? (!strncmp(name, branches[i]->name, len) &&
 175                           !branches[i]->name[len]) :
 176                    !strcmp(name, branches[i]->name))
 177                        return branches[i];
 178        }
 179
 180        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 181        ret = xcalloc(1, sizeof(struct branch));
 182        branches[branches_nr++] = ret;
 183        if (len)
 184                ret->name = xstrndup(name, len);
 185        else
 186                ret->name = xstrdup(name);
 187        refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 188        strcpy(refname, "refs/heads/");
 189        strcpy(refname + strlen("refs/heads/"), ret->name);
 190        ret->refname = refname;
 191
 192        return ret;
 193}
 194
 195static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 196{
 197        struct rewrite *ret;
 198        int i;
 199
 200        for (i = 0; i < r->rewrite_nr; i++) {
 201                if (len
 202                    ? (len == r->rewrite[i]->baselen &&
 203                       !strncmp(base, r->rewrite[i]->base, len))
 204                    : !strcmp(base, r->rewrite[i]->base))
 205                        return r->rewrite[i];
 206        }
 207
 208        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 209        ret = xcalloc(1, sizeof(struct rewrite));
 210        r->rewrite[r->rewrite_nr++] = ret;
 211        if (len) {
 212                ret->base = xstrndup(base, len);
 213                ret->baselen = len;
 214        }
 215        else {
 216                ret->base = xstrdup(base);
 217                ret->baselen = strlen(base);
 218        }
 219        return ret;
 220}
 221
 222static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 223{
 224        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 225        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 226        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 227        rewrite->instead_of_nr++;
 228}
 229
 230static void read_remotes_file(struct remote *remote)
 231{
 232        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 233
 234        if (!f)
 235                return;
 236        remote->origin = REMOTE_REMOTES;
 237        while (fgets(buffer, BUF_SIZE, f)) {
 238                int value_list;
 239                char *s, *p;
 240
 241                if (!prefixcmp(buffer, "URL:")) {
 242                        value_list = 0;
 243                        s = buffer + 4;
 244                } else if (!prefixcmp(buffer, "Push:")) {
 245                        value_list = 1;
 246                        s = buffer + 5;
 247                } else if (!prefixcmp(buffer, "Pull:")) {
 248                        value_list = 2;
 249                        s = buffer + 5;
 250                } else
 251                        continue;
 252
 253                while (isspace(*s))
 254                        s++;
 255                if (!*s)
 256                        continue;
 257
 258                p = s + strlen(s);
 259                while (isspace(p[-1]))
 260                        *--p = 0;
 261
 262                switch (value_list) {
 263                case 0:
 264                        add_url_alias(remote, xstrdup(s));
 265                        break;
 266                case 1:
 267                        add_push_refspec(remote, xstrdup(s));
 268                        break;
 269                case 2:
 270                        add_fetch_refspec(remote, xstrdup(s));
 271                        break;
 272                }
 273        }
 274        fclose(f);
 275}
 276
 277static void read_branches_file(struct remote *remote)
 278{
 279        char *frag;
 280        struct strbuf branch = STRBUF_INIT;
 281        int n = 1000;
 282        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 283        char *s, *p;
 284        int len;
 285
 286        if (!f)
 287                return;
 288        s = fgets(buffer, BUF_SIZE, f);
 289        fclose(f);
 290        if (!s)
 291                return;
 292        while (isspace(*s))
 293                s++;
 294        if (!*s)
 295                return;
 296        remote->origin = REMOTE_BRANCHES;
 297        p = s + strlen(s);
 298        while (isspace(p[-1]))
 299                *--p = 0;
 300        len = p - s;
 301        p = xmalloc(len + 1);
 302        strcpy(p, s);
 303
 304        /*
 305         * The branches file would have URL and optionally
 306         * #branch specified.  The "master" (or specified) branch is
 307         * fetched and stored in the local branch of the same name.
 308         */
 309        frag = strchr(p, '#');
 310        if (frag) {
 311                *(frag++) = '\0';
 312                strbuf_addf(&branch, "refs/heads/%s", frag);
 313        } else
 314                strbuf_addstr(&branch, "refs/heads/master");
 315
 316        strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 317        add_url_alias(remote, p);
 318        add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 319        /*
 320         * Cogito compatible push: push current HEAD to remote #branch
 321         * (master if missing)
 322         */
 323        strbuf_init(&branch, 0);
 324        strbuf_addstr(&branch, "HEAD");
 325        if (frag)
 326                strbuf_addf(&branch, ":refs/heads/%s", frag);
 327        else
 328                strbuf_addstr(&branch, ":refs/heads/master");
 329        add_push_refspec(remote, strbuf_detach(&branch, NULL));
 330        remote->fetch_tags = 1; /* always auto-follow */
 331}
 332
 333static int handle_config(const char *key, const char *value, void *cb)
 334{
 335        const char *name;
 336        const char *subkey;
 337        struct remote *remote;
 338        struct branch *branch;
 339        if (!prefixcmp(key, "branch.")) {
 340                name = key + 7;
 341                subkey = strrchr(name, '.');
 342                if (!subkey)
 343                        return 0;
 344                branch = make_branch(name, subkey - name);
 345                if (!strcmp(subkey, ".remote")) {
 346                        if (git_config_string(&branch->remote_name, key, value))
 347                                return -1;
 348                        if (branch == current_branch) {
 349                                default_remote_name = branch->remote_name;
 350                                explicit_default_remote_name = 1;
 351                        }
 352                } else if (!strcmp(subkey, ".pushremote")) {
 353                        if (branch == current_branch)
 354                                if (git_config_string(&pushremote_name, key, value))
 355                                        return -1;
 356                } else if (!strcmp(subkey, ".merge")) {
 357                        if (!value)
 358                                return config_error_nonbool(key);
 359                        add_merge(branch, xstrdup(value));
 360                }
 361                return 0;
 362        }
 363        if (!prefixcmp(key, "url.")) {
 364                struct rewrite *rewrite;
 365                name = key + 4;
 366                subkey = strrchr(name, '.');
 367                if (!subkey)
 368                        return 0;
 369                if (!strcmp(subkey, ".insteadof")) {
 370                        rewrite = make_rewrite(&rewrites, name, subkey - name);
 371                        if (!value)
 372                                return config_error_nonbool(key);
 373                        add_instead_of(rewrite, xstrdup(value));
 374                } else if (!strcmp(subkey, ".pushinsteadof")) {
 375                        rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 376                        if (!value)
 377                                return config_error_nonbool(key);
 378                        add_instead_of(rewrite, xstrdup(value));
 379                }
 380        }
 381
 382        if (prefixcmp(key,  "remote."))
 383                return 0;
 384        name = key + 7;
 385
 386        /* Handle remote.* variables */
 387        if (!strcmp(name, "pushdefault"))
 388                return git_config_string(&pushremote_name, key, value);
 389
 390        /* Handle remote.<name>.* variables */
 391        if (*name == '/') {
 392                warning("Config remote shorthand cannot begin with '/': %s",
 393                        name);
 394                return 0;
 395        }
 396        subkey = strrchr(name, '.');
 397        if (!subkey)
 398                return 0;
 399        remote = make_remote(name, subkey - name);
 400        remote->origin = REMOTE_CONFIG;
 401        if (!strcmp(subkey, ".mirror"))
 402                remote->mirror = git_config_bool(key, value);
 403        else if (!strcmp(subkey, ".skipdefaultupdate"))
 404                remote->skip_default_update = git_config_bool(key, value);
 405        else if (!strcmp(subkey, ".skipfetchall"))
 406                remote->skip_default_update = git_config_bool(key, value);
 407        else if (!strcmp(subkey, ".url")) {
 408                const char *v;
 409                if (git_config_string(&v, key, value))
 410                        return -1;
 411                add_url(remote, v);
 412        } else if (!strcmp(subkey, ".pushurl")) {
 413                const char *v;
 414                if (git_config_string(&v, key, value))
 415                        return -1;
 416                add_pushurl(remote, v);
 417        } else if (!strcmp(subkey, ".push")) {
 418                const char *v;
 419                if (git_config_string(&v, key, value))
 420                        return -1;
 421                add_push_refspec(remote, v);
 422        } else if (!strcmp(subkey, ".fetch")) {
 423                const char *v;
 424                if (git_config_string(&v, key, value))
 425                        return -1;
 426                add_fetch_refspec(remote, v);
 427        } else if (!strcmp(subkey, ".receivepack")) {
 428                const char *v;
 429                if (git_config_string(&v, key, value))
 430                        return -1;
 431                if (!remote->receivepack)
 432                        remote->receivepack = v;
 433                else
 434                        error("more than one receivepack given, using the first");
 435        } else if (!strcmp(subkey, ".uploadpack")) {
 436                const char *v;
 437                if (git_config_string(&v, key, value))
 438                        return -1;
 439                if (!remote->uploadpack)
 440                        remote->uploadpack = v;
 441                else
 442                        error("more than one uploadpack given, using the first");
 443        } else if (!strcmp(subkey, ".tagopt")) {
 444                if (!strcmp(value, "--no-tags"))
 445                        remote->fetch_tags = -1;
 446                else if (!strcmp(value, "--tags"))
 447                        remote->fetch_tags = 2;
 448        } else if (!strcmp(subkey, ".proxy")) {
 449                return git_config_string((const char **)&remote->http_proxy,
 450                                         key, value);
 451        } else if (!strcmp(subkey, ".vcs")) {
 452                return git_config_string(&remote->foreign_vcs, key, value);
 453        }
 454        return 0;
 455}
 456
 457static void alias_all_urls(void)
 458{
 459        int i, j;
 460        for (i = 0; i < remotes_nr; i++) {
 461                int add_pushurl_aliases;
 462                if (!remotes[i])
 463                        continue;
 464                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 465                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 466                }
 467                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 468                for (j = 0; j < remotes[i]->url_nr; j++) {
 469                        if (add_pushurl_aliases)
 470                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 471                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 472                }
 473        }
 474}
 475
 476static void read_config(void)
 477{
 478        unsigned char sha1[20];
 479        const char *head_ref;
 480        int flag;
 481        if (default_remote_name) /* did this already */
 482                return;
 483        default_remote_name = xstrdup("origin");
 484        current_branch = NULL;
 485        head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 486        if (head_ref && (flag & REF_ISSYMREF) &&
 487            !prefixcmp(head_ref, "refs/heads/")) {
 488                current_branch =
 489                        make_branch(head_ref + strlen("refs/heads/"), 0);
 490        }
 491        git_config(handle_config, NULL);
 492        alias_all_urls();
 493}
 494
 495/*
 496 * This function frees a refspec array.
 497 * Warning: code paths should be checked to ensure that the src
 498 *          and dst pointers are always freeable pointers as well
 499 *          as the refspec pointer itself.
 500 */
 501static void free_refspecs(struct refspec *refspec, int nr_refspec)
 502{
 503        int i;
 504
 505        if (!refspec)
 506                return;
 507
 508        for (i = 0; i < nr_refspec; i++) {
 509                free(refspec[i].src);
 510                free(refspec[i].dst);
 511        }
 512        free(refspec);
 513}
 514
 515static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 516{
 517        int i;
 518        struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 519
 520        for (i = 0; i < nr_refspec; i++) {
 521                size_t llen;
 522                int is_glob;
 523                const char *lhs, *rhs;
 524                int flags;
 525
 526                is_glob = 0;
 527
 528                lhs = refspec[i];
 529                if (*lhs == '+') {
 530                        rs[i].force = 1;
 531                        lhs++;
 532                }
 533
 534                rhs = strrchr(lhs, ':');
 535
 536                /*
 537                 * Before going on, special case ":" (or "+:") as a refspec
 538                 * for pushing matching refs.
 539                 */
 540                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 541                        rs[i].matching = 1;
 542                        continue;
 543                }
 544
 545                if (rhs) {
 546                        size_t rlen = strlen(++rhs);
 547                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 548                        rs[i].dst = xstrndup(rhs, rlen);
 549                }
 550
 551                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 552                if (1 <= llen && memchr(lhs, '*', llen)) {
 553                        if ((rhs && !is_glob) || (!rhs && fetch))
 554                                goto invalid;
 555                        is_glob = 1;
 556                } else if (rhs && is_glob) {
 557                        goto invalid;
 558                }
 559
 560                rs[i].pattern = is_glob;
 561                rs[i].src = xstrndup(lhs, llen);
 562                flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 563
 564                if (fetch) {
 565                        unsigned char unused[40];
 566
 567                        /* LHS */
 568                        if (!*rs[i].src)
 569                                ; /* empty is ok; it means "HEAD" */
 570                        else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 571                                rs[i].exact_sha1 = 1; /* ok */
 572                        else if (!check_refname_format(rs[i].src, flags))
 573                                ; /* valid looking ref is ok */
 574                        else
 575                                goto invalid;
 576                        /* RHS */
 577                        if (!rs[i].dst)
 578                                ; /* missing is ok; it is the same as empty */
 579                        else if (!*rs[i].dst)
 580                                ; /* empty is ok; it means "do not store" */
 581                        else if (!check_refname_format(rs[i].dst, flags))
 582                                ; /* valid looking ref is ok */
 583                        else
 584                                goto invalid;
 585                } else {
 586                        /*
 587                         * LHS
 588                         * - empty is allowed; it means delete.
 589                         * - when wildcarded, it must be a valid looking ref.
 590                         * - otherwise, it must be an extended SHA-1, but
 591                         *   there is no existing way to validate this.
 592                         */
 593                        if (!*rs[i].src)
 594                                ; /* empty is ok */
 595                        else if (is_glob) {
 596                                if (check_refname_format(rs[i].src, flags))
 597                                        goto invalid;
 598                        }
 599                        else
 600                                ; /* anything goes, for now */
 601                        /*
 602                         * RHS
 603                         * - missing is allowed, but LHS then must be a
 604                         *   valid looking ref.
 605                         * - empty is not allowed.
 606                         * - otherwise it must be a valid looking ref.
 607                         */
 608                        if (!rs[i].dst) {
 609                                if (check_refname_format(rs[i].src, flags))
 610                                        goto invalid;
 611                        } else if (!*rs[i].dst) {
 612                                goto invalid;
 613                        } else {
 614                                if (check_refname_format(rs[i].dst, flags))
 615                                        goto invalid;
 616                        }
 617                }
 618        }
 619        return rs;
 620
 621 invalid:
 622        if (verify) {
 623                /*
 624                 * nr_refspec must be greater than zero and i must be valid
 625                 * since it is only possible to reach this point from within
 626                 * the for loop above.
 627                 */
 628                free_refspecs(rs, i+1);
 629                return NULL;
 630        }
 631        die("Invalid refspec '%s'", refspec[i]);
 632}
 633
 634int valid_fetch_refspec(const char *fetch_refspec_str)
 635{
 636        struct refspec *refspec;
 637
 638        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 639        free_refspecs(refspec, 1);
 640        return !!refspec;
 641}
 642
 643struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 644{
 645        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 646}
 647
 648static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 649{
 650        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 651}
 652
 653void free_refspec(int nr_refspec, struct refspec *refspec)
 654{
 655        int i;
 656        for (i = 0; i < nr_refspec; i++) {
 657                free(refspec[i].src);
 658                free(refspec[i].dst);
 659        }
 660        free(refspec);
 661}
 662
 663static int valid_remote_nick(const char *name)
 664{
 665        if (!name[0] || is_dot_or_dotdot(name))
 666                return 0;
 667        return !strchr(name, '/'); /* no slash */
 668}
 669
 670static struct remote *remote_get_1(const char *name, const char *pushremote_name)
 671{
 672        struct remote *ret;
 673        int name_given = 0;
 674
 675        if (name)
 676                name_given = 1;
 677        else {
 678                if (pushremote_name) {
 679                        name = pushremote_name;
 680                        name_given = 1;
 681                } else {
 682                        name = default_remote_name;
 683                        name_given = explicit_default_remote_name;
 684                }
 685        }
 686
 687        ret = make_remote(name, 0);
 688        if (valid_remote_nick(name)) {
 689                if (!valid_remote(ret))
 690                        read_remotes_file(ret);
 691                if (!valid_remote(ret))
 692                        read_branches_file(ret);
 693        }
 694        if (name_given && !valid_remote(ret))
 695                add_url_alias(ret, name);
 696        if (!valid_remote(ret))
 697                return NULL;
 698        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 699        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 700        return ret;
 701}
 702
 703struct remote *remote_get(const char *name)
 704{
 705        read_config();
 706        return remote_get_1(name, NULL);
 707}
 708
 709struct remote *pushremote_get(const char *name)
 710{
 711        read_config();
 712        return remote_get_1(name, pushremote_name);
 713}
 714
 715int remote_is_configured(const char *name)
 716{
 717        int i;
 718        read_config();
 719
 720        for (i = 0; i < remotes_nr; i++)
 721                if (!strcmp(name, remotes[i]->name))
 722                        return 1;
 723        return 0;
 724}
 725
 726int for_each_remote(each_remote_fn fn, void *priv)
 727{
 728        int i, result = 0;
 729        read_config();
 730        for (i = 0; i < remotes_nr && !result; i++) {
 731                struct remote *r = remotes[i];
 732                if (!r)
 733                        continue;
 734                if (!r->fetch)
 735                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 736                                                       r->fetch_refspec);
 737                if (!r->push)
 738                        r->push = parse_push_refspec(r->push_refspec_nr,
 739                                                     r->push_refspec);
 740                result = fn(r, priv);
 741        }
 742        return result;
 743}
 744
 745void ref_remove_duplicates(struct ref *ref_map)
 746{
 747        struct string_list refs = STRING_LIST_INIT_NODUP;
 748        struct string_list_item *item = NULL;
 749        struct ref *prev = NULL, *next = NULL;
 750        for (; ref_map; prev = ref_map, ref_map = next) {
 751                next = ref_map->next;
 752                if (!ref_map->peer_ref)
 753                        continue;
 754
 755                item = string_list_lookup(&refs, ref_map->peer_ref->name);
 756                if (item) {
 757                        if (strcmp(((struct ref *)item->util)->name,
 758                                   ref_map->name))
 759                                die("%s tracks both %s and %s",
 760                                    ref_map->peer_ref->name,
 761                                    ((struct ref *)item->util)->name,
 762                                    ref_map->name);
 763                        prev->next = ref_map->next;
 764                        free(ref_map->peer_ref);
 765                        free(ref_map);
 766                        ref_map = prev; /* skip this; we freed it */
 767                        continue;
 768                }
 769
 770                item = string_list_insert(&refs, ref_map->peer_ref->name);
 771                item->util = ref_map;
 772        }
 773        string_list_clear(&refs, 0);
 774}
 775
 776int remote_has_url(struct remote *remote, const char *url)
 777{
 778        int i;
 779        for (i = 0; i < remote->url_nr; i++) {
 780                if (!strcmp(remote->url[i], url))
 781                        return 1;
 782        }
 783        return 0;
 784}
 785
 786static int match_name_with_pattern(const char *key, const char *name,
 787                                   const char *value, char **result)
 788{
 789        const char *kstar = strchr(key, '*');
 790        size_t klen;
 791        size_t ksuffixlen;
 792        size_t namelen;
 793        int ret;
 794        if (!kstar)
 795                die("Key '%s' of pattern had no '*'", key);
 796        klen = kstar - key;
 797        ksuffixlen = strlen(kstar + 1);
 798        namelen = strlen(name);
 799        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 800                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 801        if (ret && value) {
 802                const char *vstar = strchr(value, '*');
 803                size_t vlen;
 804                size_t vsuffixlen;
 805                if (!vstar)
 806                        die("Value '%s' of pattern has no '*'", value);
 807                vlen = vstar - value;
 808                vsuffixlen = strlen(vstar + 1);
 809                *result = xmalloc(vlen + vsuffixlen +
 810                                  strlen(name) -
 811                                  klen - ksuffixlen + 1);
 812                strncpy(*result, value, vlen);
 813                strncpy(*result + vlen,
 814                        name + klen, namelen - klen - ksuffixlen);
 815                strcpy(*result + vlen + namelen - klen - ksuffixlen,
 816                       vstar + 1);
 817        }
 818        return ret;
 819}
 820
 821static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 822{
 823        int i;
 824        int find_src = !query->src;
 825
 826        if (find_src && !query->dst)
 827                return error("query_refspecs: need either src or dst");
 828
 829        for (i = 0; i < ref_count; i++) {
 830                struct refspec *refspec = &refs[i];
 831                const char *key = find_src ? refspec->dst : refspec->src;
 832                const char *value = find_src ? refspec->src : refspec->dst;
 833                const char *needle = find_src ? query->dst : query->src;
 834                char **result = find_src ? &query->src : &query->dst;
 835
 836                if (!refspec->dst)
 837                        continue;
 838                if (refspec->pattern) {
 839                        if (match_name_with_pattern(key, needle, value, result)) {
 840                                query->force = refspec->force;
 841                                return 0;
 842                        }
 843                } else if (!strcmp(needle, key)) {
 844                        *result = xstrdup(value);
 845                        query->force = refspec->force;
 846                        return 0;
 847                }
 848        }
 849        return -1;
 850}
 851
 852char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 853                     const char *name)
 854{
 855        struct refspec query;
 856
 857        memset(&query, 0, sizeof(struct refspec));
 858        query.src = (char *)name;
 859
 860        if (query_refspecs(refspecs, nr_refspec, &query))
 861                return NULL;
 862
 863        return query.dst;
 864}
 865
 866int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 867{
 868        return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 869}
 870
 871static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 872                const char *name)
 873{
 874        size_t len = strlen(name);
 875        struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 876        memcpy(ref->name, prefix, prefixlen);
 877        memcpy(ref->name + prefixlen, name, len);
 878        return ref;
 879}
 880
 881struct ref *alloc_ref(const char *name)
 882{
 883        return alloc_ref_with_prefix("", 0, name);
 884}
 885
 886struct ref *copy_ref(const struct ref *ref)
 887{
 888        struct ref *cpy;
 889        size_t len;
 890        if (!ref)
 891                return NULL;
 892        len = strlen(ref->name);
 893        cpy = xmalloc(sizeof(struct ref) + len + 1);
 894        memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 895        cpy->next = NULL;
 896        cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 897        cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 898        cpy->peer_ref = copy_ref(ref->peer_ref);
 899        return cpy;
 900}
 901
 902struct ref *copy_ref_list(const struct ref *ref)
 903{
 904        struct ref *ret = NULL;
 905        struct ref **tail = &ret;
 906        while (ref) {
 907                *tail = copy_ref(ref);
 908                ref = ref->next;
 909                tail = &((*tail)->next);
 910        }
 911        return ret;
 912}
 913
 914static void free_ref(struct ref *ref)
 915{
 916        if (!ref)
 917                return;
 918        free_ref(ref->peer_ref);
 919        free(ref->remote_status);
 920        free(ref->symref);
 921        free(ref);
 922}
 923
 924void free_refs(struct ref *ref)
 925{
 926        struct ref *next;
 927        while (ref) {
 928                next = ref->next;
 929                free_ref(ref);
 930                ref = next;
 931        }
 932}
 933
 934int ref_compare_name(const void *va, const void *vb)
 935{
 936        const struct ref *a = va, *b = vb;
 937        return strcmp(a->name, b->name);
 938}
 939
 940static void *ref_list_get_next(const void *a)
 941{
 942        return ((const struct ref *)a)->next;
 943}
 944
 945static void ref_list_set_next(void *a, void *next)
 946{
 947        ((struct ref *)a)->next = next;
 948}
 949
 950void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 951{
 952        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 953}
 954
 955static int count_refspec_match(const char *pattern,
 956                               struct ref *refs,
 957                               struct ref **matched_ref)
 958{
 959        int patlen = strlen(pattern);
 960        struct ref *matched_weak = NULL;
 961        struct ref *matched = NULL;
 962        int weak_match = 0;
 963        int match = 0;
 964
 965        for (weak_match = match = 0; refs; refs = refs->next) {
 966                char *name = refs->name;
 967                int namelen = strlen(name);
 968
 969                if (!refname_match(pattern, name, ref_rev_parse_rules))
 970                        continue;
 971
 972                /* A match is "weak" if it is with refs outside
 973                 * heads or tags, and did not specify the pattern
 974                 * in full (e.g. "refs/remotes/origin/master") or at
 975                 * least from the toplevel (e.g. "remotes/origin/master");
 976                 * otherwise "git push $URL master" would result in
 977                 * ambiguity between remotes/origin/master and heads/master
 978                 * at the remote site.
 979                 */
 980                if (namelen != patlen &&
 981                    patlen != namelen - 5 &&
 982                    prefixcmp(name, "refs/heads/") &&
 983                    prefixcmp(name, "refs/tags/")) {
 984                        /* We want to catch the case where only weak
 985                         * matches are found and there are multiple
 986                         * matches, and where more than one strong
 987                         * matches are found, as ambiguous.  One
 988                         * strong match with zero or more weak matches
 989                         * are acceptable as a unique match.
 990                         */
 991                        matched_weak = refs;
 992                        weak_match++;
 993                }
 994                else {
 995                        matched = refs;
 996                        match++;
 997                }
 998        }
 999        if (!matched) {
1000                *matched_ref = matched_weak;
1001                return weak_match;
1002        }
1003        else {
1004                *matched_ref = matched;
1005                return match;
1006        }
1007}
1008
1009static void tail_link_ref(struct ref *ref, struct ref ***tail)
1010{
1011        **tail = ref;
1012        while (ref->next)
1013                ref = ref->next;
1014        *tail = &ref->next;
1015}
1016
1017static struct ref *alloc_delete_ref(void)
1018{
1019        struct ref *ref = alloc_ref("(delete)");
1020        hashclr(ref->new_sha1);
1021        return ref;
1022}
1023
1024static struct ref *try_explicit_object_name(const char *name)
1025{
1026        unsigned char sha1[20];
1027        struct ref *ref;
1028
1029        if (!*name)
1030                return alloc_delete_ref();
1031        if (get_sha1(name, sha1))
1032                return NULL;
1033        ref = alloc_ref(name);
1034        hashcpy(ref->new_sha1, sha1);
1035        return ref;
1036}
1037
1038static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1039{
1040        struct ref *ret = alloc_ref(name);
1041        tail_link_ref(ret, tail);
1042        return ret;
1043}
1044
1045static char *guess_ref(const char *name, struct ref *peer)
1046{
1047        struct strbuf buf = STRBUF_INIT;
1048        unsigned char sha1[20];
1049
1050        const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1051        if (!r)
1052                return NULL;
1053
1054        if (!prefixcmp(r, "refs/heads/"))
1055                strbuf_addstr(&buf, "refs/heads/");
1056        else if (!prefixcmp(r, "refs/tags/"))
1057                strbuf_addstr(&buf, "refs/tags/");
1058        else
1059                return NULL;
1060
1061        strbuf_addstr(&buf, name);
1062        return strbuf_detach(&buf, NULL);
1063}
1064
1065static int match_explicit(struct ref *src, struct ref *dst,
1066                          struct ref ***dst_tail,
1067                          struct refspec *rs)
1068{
1069        struct ref *matched_src, *matched_dst;
1070        int copy_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        switch (count_refspec_match(rs->src, src, &matched_src)) {
1080        case 1:
1081                copy_src = 1;
1082                break;
1083        case 0:
1084                /* The source could be in the get_sha1() format
1085                 * not a reference name.  :refs/other is a
1086                 * way to delete 'other' ref at the remote end.
1087                 */
1088                matched_src = try_explicit_object_name(rs->src);
1089                if (!matched_src)
1090                        return error("src refspec %s does not match any.", rs->src);
1091                copy_src = 0;
1092                break;
1093        default:
1094                return error("src refspec %s matches more than one.", rs->src);
1095        }
1096
1097        if (!dst_value) {
1098                unsigned char sha1[20];
1099                int flag;
1100
1101                dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1102                if (!dst_value ||
1103                    ((flag & REF_ISSYMREF) &&
1104                     prefixcmp(dst_value, "refs/heads/")))
1105                        die("%s cannot be resolved to branch.",
1106                            matched_src->name);
1107        }
1108
1109        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1110        case 1:
1111                break;
1112        case 0:
1113                if (!memcmp(dst_value, "refs/", 5))
1114                        matched_dst = make_linked_ref(dst_value, dst_tail);
1115                else if (is_null_sha1(matched_src->new_sha1))
1116                        error("unable to delete '%s': remote ref does not exist",
1117                              dst_value);
1118                else if ((dst_guess = guess_ref(dst_value, matched_src)))
1119                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1120                else
1121                        error("unable to push to unqualified destination: %s\n"
1122                              "The destination refspec neither matches an "
1123                              "existing ref on the remote nor\n"
1124                              "begins with refs/, and we are unable to "
1125                              "guess a prefix based on the source ref.",
1126                              dst_value);
1127                break;
1128        default:
1129                matched_dst = NULL;
1130                error("dst refspec %s matches more than one.",
1131                      dst_value);
1132                break;
1133        }
1134        if (!matched_dst)
1135                return -1;
1136        if (matched_dst->peer_ref)
1137                return error("dst ref %s receives from more than one src.",
1138                      matched_dst->name);
1139        else {
1140                matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1141                matched_dst->force = rs->force;
1142        }
1143        return 0;
1144}
1145
1146static int match_explicit_refs(struct ref *src, struct ref *dst,
1147                               struct ref ***dst_tail, struct refspec *rs,
1148                               int rs_nr)
1149{
1150        int i, errs;
1151        for (i = errs = 0; i < rs_nr; i++)
1152                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1153        return errs;
1154}
1155
1156static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1157                int send_mirror, int direction, const struct refspec **ret_pat)
1158{
1159        const struct refspec *pat;
1160        char *name;
1161        int i;
1162        int matching_refs = -1;
1163        for (i = 0; i < rs_nr; i++) {
1164                if (rs[i].matching &&
1165                    (matching_refs == -1 || rs[i].force)) {
1166                        matching_refs = i;
1167                        continue;
1168                }
1169
1170                if (rs[i].pattern) {
1171                        const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1172                        int match;
1173                        if (direction == FROM_SRC)
1174                                match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1175                        else
1176                                match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1177                        if (match) {
1178                                matching_refs = i;
1179                                break;
1180                        }
1181                }
1182        }
1183        if (matching_refs == -1)
1184                return NULL;
1185
1186        pat = rs + matching_refs;
1187        if (pat->matching) {
1188                /*
1189                 * "matching refs"; traditionally we pushed everything
1190                 * including refs outside refs/heads/ hierarchy, but
1191                 * that does not make much sense these days.
1192                 */
1193                if (!send_mirror && prefixcmp(ref->name, "refs/heads/"))
1194                        return NULL;
1195                name = xstrdup(ref->name);
1196        }
1197        if (ret_pat)
1198                *ret_pat = pat;
1199        return name;
1200}
1201
1202static struct ref **tail_ref(struct ref **head)
1203{
1204        struct ref **tail = head;
1205        while (*tail)
1206                tail = &((*tail)->next);
1207        return tail;
1208}
1209
1210struct tips {
1211        struct commit **tip;
1212        int nr, alloc;
1213};
1214
1215static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1216{
1217        struct commit *commit;
1218
1219        if (is_null_sha1(sha1))
1220                return;
1221        commit = lookup_commit_reference_gently(sha1, 1);
1222        if (!commit || (commit->object.flags & TMP_MARK))
1223                return;
1224        commit->object.flags |= TMP_MARK;
1225        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1226        tips->tip[tips->nr++] = commit;
1227}
1228
1229static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1230{
1231        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1232        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1233        struct string_list_item *item;
1234        struct ref *ref;
1235        struct tips sent_tips;
1236
1237        /*
1238         * Collect everything we know they would have at the end of
1239         * this push, and collect all tags they have.
1240         */
1241        memset(&sent_tips, 0, sizeof(sent_tips));
1242        for (ref = *dst; ref; ref = ref->next) {
1243                if (ref->peer_ref &&
1244                    !is_null_sha1(ref->peer_ref->new_sha1))
1245                        add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1246                else
1247                        add_to_tips(&sent_tips, ref->old_sha1);
1248                if (!prefixcmp(ref->name, "refs/tags/"))
1249                        string_list_append(&dst_tag, ref->name);
1250        }
1251        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1252
1253        sort_string_list(&dst_tag);
1254
1255        /* Collect tags they do not have. */
1256        for (ref = src; ref; ref = ref->next) {
1257                if (prefixcmp(ref->name, "refs/tags/"))
1258                        continue; /* not a tag */
1259                if (string_list_has_string(&dst_tag, ref->name))
1260                        continue; /* they already have it */
1261                if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1262                        continue; /* be conservative */
1263                item = string_list_append(&src_tag, ref->name);
1264                item->util = ref;
1265        }
1266        string_list_clear(&dst_tag, 0);
1267
1268        /*
1269         * At this point, src_tag lists tags that are missing from
1270         * dst, and sent_tips lists the tips we are pushing or those
1271         * that we know they already have. An element in the src_tag
1272         * that is an ancestor of any of the sent_tips needs to be
1273         * sent to the other side.
1274         */
1275        if (sent_tips.nr) {
1276                for_each_string_list_item(item, &src_tag) {
1277                        struct ref *ref = item->util;
1278                        struct ref *dst_ref;
1279                        struct commit *commit;
1280
1281                        if (is_null_sha1(ref->new_sha1))
1282                                continue;
1283                        commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1284                        if (!commit)
1285                                /* not pushing a commit, which is not an error */
1286                                continue;
1287
1288                        /*
1289                         * Is this tag, which they do not have, reachable from
1290                         * any of the commits we are sending?
1291                         */
1292                        if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1293                                continue;
1294
1295                        /* Add it in */
1296                        dst_ref = make_linked_ref(ref->name, dst_tail);
1297                        hashcpy(dst_ref->new_sha1, ref->new_sha1);
1298                        dst_ref->peer_ref = copy_ref(ref);
1299                }
1300        }
1301        string_list_clear(&src_tag, 0);
1302        free(sent_tips.tip);
1303}
1304
1305/*
1306 * Given the set of refs the local repository has, the set of refs the
1307 * remote repository has, and the refspec used for push, determine
1308 * what remote refs we will update and with what value by setting
1309 * peer_ref (which object is being pushed) and force (if the push is
1310 * forced) in elements of "dst". The function may add new elements to
1311 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1312 */
1313int match_push_refs(struct ref *src, struct ref **dst,
1314                    int nr_refspec, const char **refspec, int flags)
1315{
1316        struct refspec *rs;
1317        int send_all = flags & MATCH_REFS_ALL;
1318        int send_mirror = flags & MATCH_REFS_MIRROR;
1319        int send_prune = flags & MATCH_REFS_PRUNE;
1320        int errs;
1321        static const char *default_refspec[] = { ":", NULL };
1322        struct ref *ref, **dst_tail = tail_ref(dst);
1323
1324        if (!nr_refspec) {
1325                nr_refspec = 1;
1326                refspec = default_refspec;
1327        }
1328        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1329        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1330
1331        /* pick the remainder */
1332        for (ref = src; ref; ref = ref->next) {
1333                struct ref *dst_peer;
1334                const struct refspec *pat = NULL;
1335                char *dst_name;
1336
1337                dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1338                if (!dst_name)
1339                        continue;
1340
1341                dst_peer = find_ref_by_name(*dst, dst_name);
1342                if (dst_peer) {
1343                        if (dst_peer->peer_ref)
1344                                /* We're already sending something to this ref. */
1345                                goto free_name;
1346                } else {
1347                        if (pat->matching && !(send_all || send_mirror))
1348                                /*
1349                                 * Remote doesn't have it, and we have no
1350                                 * explicit pattern, and we don't have
1351                                 * --all nor --mirror.
1352                                 */
1353                                goto free_name;
1354
1355                        /* Create a new one and link it */
1356                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1357                        hashcpy(dst_peer->new_sha1, ref->new_sha1);
1358                }
1359                dst_peer->peer_ref = copy_ref(ref);
1360                dst_peer->force = pat->force;
1361        free_name:
1362                free(dst_name);
1363        }
1364
1365        if (flags & MATCH_REFS_FOLLOW_TAGS)
1366                add_missing_tags(src, dst, &dst_tail);
1367
1368        if (send_prune) {
1369                /* check for missing refs on the remote */
1370                for (ref = *dst; ref; ref = ref->next) {
1371                        char *src_name;
1372
1373                        if (ref->peer_ref)
1374                                /* We're already sending something to this ref. */
1375                                continue;
1376
1377                        src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1378                        if (src_name) {
1379                                if (!find_ref_by_name(src, src_name))
1380                                        ref->peer_ref = alloc_delete_ref();
1381                                free(src_name);
1382                        }
1383                }
1384        }
1385        if (errs)
1386                return -1;
1387        return 0;
1388}
1389
1390void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1391        int force_update)
1392{
1393        struct ref *ref;
1394
1395        for (ref = remote_refs; ref; ref = ref->next) {
1396                int force_ref_update = ref->force || force_update;
1397
1398                if (ref->peer_ref)
1399                        hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1400                else if (!send_mirror)
1401                        continue;
1402
1403                ref->deletion = is_null_sha1(ref->new_sha1);
1404                if (!ref->deletion &&
1405                        !hashcmp(ref->old_sha1, ref->new_sha1)) {
1406                        ref->status = REF_STATUS_UPTODATE;
1407                        continue;
1408                }
1409
1410                /*
1411                 * Decide whether an individual refspec A:B can be
1412                 * pushed.  The push will succeed if any of the
1413                 * following are true:
1414                 *
1415                 * (1) the remote reference B does not exist
1416                 *
1417                 * (2) the remote reference B is being removed (i.e.,
1418                 *     pushing :B where no source is specified)
1419                 *
1420                 * (3) the destination is not under refs/tags/, and
1421                 *     if the old and new value is a commit, the new
1422                 *     is a descendant of the old.
1423                 *
1424                 * (4) it is forced using the +A:B notation, or by
1425                 *     passing the --force argument
1426                 */
1427
1428                if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1429                        int why = 0; /* why would this push require --force? */
1430
1431                        if (!prefixcmp(ref->name, "refs/tags/"))
1432                                why = REF_STATUS_REJECT_ALREADY_EXISTS;
1433                        else if (!has_sha1_file(ref->old_sha1))
1434                                why = REF_STATUS_REJECT_FETCH_FIRST;
1435                        else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1436                                 !lookup_commit_reference_gently(ref->new_sha1, 1))
1437                                why = REF_STATUS_REJECT_NEEDS_FORCE;
1438                        else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1439                                why = REF_STATUS_REJECT_NONFASTFORWARD;
1440
1441                        if (!force_ref_update)
1442                                ref->status = why;
1443                        else if (why)
1444                                ref->forced_update = 1;
1445                }
1446        }
1447}
1448
1449struct branch *branch_get(const char *name)
1450{
1451        struct branch *ret;
1452
1453        read_config();
1454        if (!name || !*name || !strcmp(name, "HEAD"))
1455                ret = current_branch;
1456        else
1457                ret = make_branch(name, 0);
1458        if (ret && ret->remote_name) {
1459                ret->remote = remote_get(ret->remote_name);
1460                if (ret->merge_nr) {
1461                        int i;
1462                        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1463                        for (i = 0; i < ret->merge_nr; i++) {
1464                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1465                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1466                                if (remote_find_tracking(ret->remote, ret->merge[i])
1467                                    && !strcmp(ret->remote_name, "."))
1468                                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1469                        }
1470                }
1471        }
1472        return ret;
1473}
1474
1475int branch_has_merge_config(struct branch *branch)
1476{
1477        return branch && !!branch->merge;
1478}
1479
1480int branch_merge_matches(struct branch *branch,
1481                                 int i,
1482                                 const char *refname)
1483{
1484        if (!branch || i < 0 || i >= branch->merge_nr)
1485                return 0;
1486        return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1487}
1488
1489static int ignore_symref_update(const char *refname)
1490{
1491        unsigned char sha1[20];
1492        int flag;
1493
1494        if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1495                return 0; /* non-existing refs are OK */
1496        return (flag & REF_ISSYMREF);
1497}
1498
1499static struct ref *get_expanded_map(const struct ref *remote_refs,
1500                                    const struct refspec *refspec)
1501{
1502        const struct ref *ref;
1503        struct ref *ret = NULL;
1504        struct ref **tail = &ret;
1505
1506        char *expn_name;
1507
1508        for (ref = remote_refs; ref; ref = ref->next) {
1509                if (strchr(ref->name, '^'))
1510                        continue; /* a dereference item */
1511                if (match_name_with_pattern(refspec->src, ref->name,
1512                                            refspec->dst, &expn_name) &&
1513                    !ignore_symref_update(expn_name)) {
1514                        struct ref *cpy = copy_ref(ref);
1515
1516                        cpy->peer_ref = alloc_ref(expn_name);
1517                        free(expn_name);
1518                        if (refspec->force)
1519                                cpy->peer_ref->force = 1;
1520                        *tail = cpy;
1521                        tail = &cpy->next;
1522                }
1523        }
1524
1525        return ret;
1526}
1527
1528static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1529{
1530        const struct ref *ref;
1531        for (ref = refs; ref; ref = ref->next) {
1532                if (refname_match(name, ref->name, ref_fetch_rules))
1533                        return ref;
1534        }
1535        return NULL;
1536}
1537
1538struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1539{
1540        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1541
1542        if (!ref)
1543                return NULL;
1544
1545        return copy_ref(ref);
1546}
1547
1548static struct ref *get_local_ref(const char *name)
1549{
1550        if (!name || name[0] == '\0')
1551                return NULL;
1552
1553        if (!prefixcmp(name, "refs/"))
1554                return alloc_ref(name);
1555
1556        if (!prefixcmp(name, "heads/") ||
1557            !prefixcmp(name, "tags/") ||
1558            !prefixcmp(name, "remotes/"))
1559                return alloc_ref_with_prefix("refs/", 5, name);
1560
1561        return alloc_ref_with_prefix("refs/heads/", 11, name);
1562}
1563
1564int get_fetch_map(const struct ref *remote_refs,
1565                  const struct refspec *refspec,
1566                  struct ref ***tail,
1567                  int missing_ok)
1568{
1569        struct ref *ref_map, **rmp;
1570
1571        if (refspec->pattern) {
1572                ref_map = get_expanded_map(remote_refs, refspec);
1573        } else {
1574                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1575
1576                if (refspec->exact_sha1) {
1577                        ref_map = alloc_ref(name);
1578                        get_sha1_hex(name, ref_map->old_sha1);
1579                } else {
1580                        ref_map = get_remote_ref(remote_refs, name);
1581                }
1582                if (!missing_ok && !ref_map)
1583                        die("Couldn't find remote ref %s", name);
1584                if (ref_map) {
1585                        ref_map->peer_ref = get_local_ref(refspec->dst);
1586                        if (ref_map->peer_ref && refspec->force)
1587                                ref_map->peer_ref->force = 1;
1588                }
1589        }
1590
1591        for (rmp = &ref_map; *rmp; ) {
1592                if ((*rmp)->peer_ref) {
1593                        if (prefixcmp((*rmp)->peer_ref->name, "refs/") ||
1594                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1595                                struct ref *ignore = *rmp;
1596                                error("* Ignoring funny ref '%s' locally",
1597                                      (*rmp)->peer_ref->name);
1598                                *rmp = (*rmp)->next;
1599                                free(ignore->peer_ref);
1600                                free(ignore);
1601                                continue;
1602                        }
1603                }
1604                rmp = &((*rmp)->next);
1605        }
1606
1607        if (ref_map)
1608                tail_link_ref(ref_map, tail);
1609
1610        return 0;
1611}
1612
1613int resolve_remote_symref(struct ref *ref, struct ref *list)
1614{
1615        if (!ref->symref)
1616                return 0;
1617        for (; list; list = list->next)
1618                if (!strcmp(ref->symref, list->name)) {
1619                        hashcpy(ref->old_sha1, list->old_sha1);
1620                        return 0;
1621                }
1622        return 1;
1623}
1624
1625static void unmark_and_free(struct commit_list *list, unsigned int mark)
1626{
1627        while (list) {
1628                struct commit_list *temp = list;
1629                temp->item->object.flags &= ~mark;
1630                list = temp->next;
1631                free(temp);
1632        }
1633}
1634
1635int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1636{
1637        struct object *o;
1638        struct commit *old, *new;
1639        struct commit_list *list, *used;
1640        int found = 0;
1641
1642        /*
1643         * Both new and old must be commit-ish and new is descendant of
1644         * old.  Otherwise we require --force.
1645         */
1646        o = deref_tag(parse_object(old_sha1), NULL, 0);
1647        if (!o || o->type != OBJ_COMMIT)
1648                return 0;
1649        old = (struct commit *) o;
1650
1651        o = deref_tag(parse_object(new_sha1), NULL, 0);
1652        if (!o || o->type != OBJ_COMMIT)
1653                return 0;
1654        new = (struct commit *) o;
1655
1656        if (parse_commit(new) < 0)
1657                return 0;
1658
1659        used = list = NULL;
1660        commit_list_insert(new, &list);
1661        while (list) {
1662                new = pop_most_recent_commit(&list, TMP_MARK);
1663                commit_list_insert(new, &used);
1664                if (new == old) {
1665                        found = 1;
1666                        break;
1667                }
1668        }
1669        unmark_and_free(list, TMP_MARK);
1670        unmark_and_free(used, TMP_MARK);
1671        return found;
1672}
1673
1674/*
1675 * Return true if there is anything to report, otherwise false.
1676 */
1677int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1678{
1679        unsigned char sha1[20];
1680        struct commit *ours, *theirs;
1681        char symmetric[84];
1682        struct rev_info revs;
1683        const char *rev_argv[10], *base;
1684        int rev_argc;
1685
1686        /*
1687         * Nothing to report unless we are marked to build on top of
1688         * somebody else.
1689         */
1690        if (!branch ||
1691            !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1692                return 0;
1693
1694        /*
1695         * If what we used to build on no longer exists, there is
1696         * nothing to report.
1697         */
1698        base = branch->merge[0]->dst;
1699        if (read_ref(base, sha1))
1700                return 0;
1701        theirs = lookup_commit_reference(sha1);
1702        if (!theirs)
1703                return 0;
1704
1705        if (read_ref(branch->refname, sha1))
1706                return 0;
1707        ours = lookup_commit_reference(sha1);
1708        if (!ours)
1709                return 0;
1710
1711        /* are we the same? */
1712        if (theirs == ours)
1713                return 0;
1714
1715        /* Run "rev-list --left-right ours...theirs" internally... */
1716        rev_argc = 0;
1717        rev_argv[rev_argc++] = NULL;
1718        rev_argv[rev_argc++] = "--left-right";
1719        rev_argv[rev_argc++] = symmetric;
1720        rev_argv[rev_argc++] = "--";
1721        rev_argv[rev_argc] = NULL;
1722
1723        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1724        strcpy(symmetric + 40, "...");
1725        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1726
1727        init_revisions(&revs, NULL);
1728        setup_revisions(rev_argc, rev_argv, &revs, NULL);
1729        prepare_revision_walk(&revs);
1730
1731        /* ... and count the commits on each side. */
1732        *num_ours = 0;
1733        *num_theirs = 0;
1734        while (1) {
1735                struct commit *c = get_revision(&revs);
1736                if (!c)
1737                        break;
1738                if (c->object.flags & SYMMETRIC_LEFT)
1739                        (*num_ours)++;
1740                else
1741                        (*num_theirs)++;
1742        }
1743
1744        /* clear object flags smudged by the above traversal */
1745        clear_commit_marks(ours, ALL_REV_FLAGS);
1746        clear_commit_marks(theirs, ALL_REV_FLAGS);
1747        return 1;
1748}
1749
1750/*
1751 * Return true when there is anything to report, otherwise false.
1752 */
1753int format_tracking_info(struct branch *branch, struct strbuf *sb)
1754{
1755        int num_ours, num_theirs;
1756        const char *base;
1757
1758        if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1759                return 0;
1760
1761        base = branch->merge[0]->dst;
1762        base = shorten_unambiguous_ref(base, 0);
1763        if (!num_theirs) {
1764                strbuf_addf(sb,
1765                        Q_("Your branch is ahead of '%s' by %d commit.\n",
1766                           "Your branch is ahead of '%s' by %d commits.\n",
1767                           num_ours),
1768                        base, num_ours);
1769                if (advice_status_hints)
1770                        strbuf_addf(sb,
1771                                _("  (use \"git push\" to publish your local commits)\n"));
1772        } else if (!num_ours) {
1773                strbuf_addf(sb,
1774                        Q_("Your branch is behind '%s' by %d commit, "
1775                               "and can be fast-forwarded.\n",
1776                           "Your branch is behind '%s' by %d commits, "
1777                               "and can be fast-forwarded.\n",
1778                           num_theirs),
1779                        base, num_theirs);
1780                if (advice_status_hints)
1781                        strbuf_addf(sb,
1782                                _("  (use \"git pull\" to update your local branch)\n"));
1783        } else {
1784                strbuf_addf(sb,
1785                        Q_("Your branch and '%s' have diverged,\n"
1786                               "and have %d and %d different commit each, "
1787                               "respectively.\n",
1788                           "Your branch and '%s' have diverged,\n"
1789                               "and have %d and %d different commits each, "
1790                               "respectively.\n",
1791                           num_theirs),
1792                        base, num_ours, num_theirs);
1793                if (advice_status_hints)
1794                        strbuf_addf(sb,
1795                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1796        }
1797        return 1;
1798}
1799
1800static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1801{
1802        struct ref ***local_tail = cb_data;
1803        struct ref *ref;
1804        int len;
1805
1806        /* we already know it starts with refs/ to get here */
1807        if (check_refname_format(refname + 5, 0))
1808                return 0;
1809
1810        len = strlen(refname) + 1;
1811        ref = xcalloc(1, sizeof(*ref) + len);
1812        hashcpy(ref->new_sha1, sha1);
1813        memcpy(ref->name, refname, len);
1814        **local_tail = ref;
1815        *local_tail = &ref->next;
1816        return 0;
1817}
1818
1819struct ref *get_local_heads(void)
1820{
1821        struct ref *local_refs = NULL, **local_tail = &local_refs;
1822        for_each_ref(one_local_ref, &local_tail);
1823        return local_refs;
1824}
1825
1826struct ref *guess_remote_head(const struct ref *head,
1827                              const struct ref *refs,
1828                              int all)
1829{
1830        const struct ref *r;
1831        struct ref *list = NULL;
1832        struct ref **tail = &list;
1833
1834        if (!head)
1835                return NULL;
1836
1837        /*
1838         * Some transports support directly peeking at
1839         * where HEAD points; if that is the case, then
1840         * we don't have to guess.
1841         */
1842        if (head->symref)
1843                return copy_ref(find_ref_by_name(refs, head->symref));
1844
1845        /* If refs/heads/master could be right, it is. */
1846        if (!all) {
1847                r = find_ref_by_name(refs, "refs/heads/master");
1848                if (r && !hashcmp(r->old_sha1, head->old_sha1))
1849                        return copy_ref(r);
1850        }
1851
1852        /* Look for another ref that points there */
1853        for (r = refs; r; r = r->next) {
1854                if (r != head &&
1855                    !prefixcmp(r->name, "refs/heads/") &&
1856                    !hashcmp(r->old_sha1, head->old_sha1)) {
1857                        *tail = copy_ref(r);
1858                        tail = &((*tail)->next);
1859                        if (!all)
1860                                break;
1861                }
1862        }
1863
1864        return list;
1865}
1866
1867struct stale_heads_info {
1868        struct string_list *ref_names;
1869        struct ref **stale_refs_tail;
1870        struct refspec *refs;
1871        int ref_count;
1872};
1873
1874static int get_stale_heads_cb(const char *refname,
1875        const unsigned char *sha1, int flags, void *cb_data)
1876{
1877        struct stale_heads_info *info = cb_data;
1878        struct refspec query;
1879        memset(&query, 0, sizeof(struct refspec));
1880        query.dst = (char *)refname;
1881
1882        if (query_refspecs(info->refs, info->ref_count, &query))
1883                return 0; /* No matches */
1884
1885        /*
1886         * If we did find a suitable refspec and it's not a symref and
1887         * it's not in the list of refs that currently exist in that
1888         * remote we consider it to be stale.
1889         */
1890        if (!((flags & REF_ISSYMREF) ||
1891              string_list_has_string(info->ref_names, query.src))) {
1892                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1893                hashcpy(ref->new_sha1, sha1);
1894        }
1895
1896        free(query.src);
1897        return 0;
1898}
1899
1900struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
1901{
1902        struct ref *ref, *stale_refs = NULL;
1903        struct string_list ref_names = STRING_LIST_INIT_NODUP;
1904        struct stale_heads_info info;
1905        info.ref_names = &ref_names;
1906        info.stale_refs_tail = &stale_refs;
1907        info.refs = refs;
1908        info.ref_count = ref_count;
1909        for (ref = fetch_map; ref; ref = ref->next)
1910                string_list_append(&ref_names, ref->name);
1911        sort_string_list(&ref_names);
1912        for_each_ref(get_stale_heads_cb, &info);
1913        string_list_clear(&ref_names, 0);
1914        return stale_refs;
1915}