Andrew's git / gitweb.git / config.c
?
config.con commit git-svn: add support for --stat in the log command (488a63e)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 * Copyright (C) Johannes Schindelin, 2005
   6 *
   7 */
   8#include "cache.h"
   9
  10#define MAXNAME (256)
  11
  12static FILE *config_file;
  13static const char *config_file_name;
  14static int config_linenr;
  15static int get_next_char(void)
  16{
  17        int c;
  18        FILE *f;
  19
  20        c = '\n';
  21        if ((f = config_file) != NULL) {
  22                c = fgetc(f);
  23                if (c == '\r') {
  24                        /* DOS like systems */
  25                        c = fgetc(f);
  26                        if (c != '\n') {
  27                                ungetc(c, f);
  28                                c = '\r';
  29                        }
  30                }
  31                if (c == '\n')
  32                        config_linenr++;
  33                if (c == EOF) {
  34                        config_file = NULL;
  35                        c = '\n';
  36                }
  37        }
  38        return c;
  39}
  40
  41static char *parse_value(void)
  42{
  43        static char value[1024];
  44        int quote = 0, comment = 0, len = 0, space = 0;
  45
  46        for (;;) {
  47                int c = get_next_char();
  48                if (len >= sizeof(value))
  49                        return NULL;
  50                if (c == '\n') {
  51                        if (quote)
  52                                return NULL;
  53                        value[len] = 0;
  54                        return value;
  55                }
  56                if (comment)
  57                        continue;
  58                if (isspace(c) && !quote) {
  59                        space = 1;
  60                        continue;
  61                }
  62                if (!quote) {
  63                        if (c == ';' || c == '#') {
  64                                comment = 1;
  65                                continue;
  66                        }
  67                }
  68                if (space) {
  69                        if (len)
  70                                value[len++] = ' ';
  71                        space = 0;
  72                }
  73                if (c == '\\') {
  74                        c = get_next_char();
  75                        switch (c) {
  76                        case '\n':
  77                                continue;
  78                        case 't':
  79                                c = '\t';
  80                                break;
  81                        case 'b':
  82                                c = '\b';
  83                                break;
  84                        case 'n':
  85                                c = '\n';
  86                                break;
  87                        /* Some characters escape as themselves */
  88                        case '\\': case '"':
  89                                break;
  90                        /* Reject unknown escape sequences */
  91                        default:
  92                                return NULL;
  93                        }
  94                        value[len++] = c;
  95                        continue;
  96                }
  97                if (c == '"') {
  98                        quote = 1-quote;
  99                        continue;
 100                }
 101                value[len++] = c;
 102        }
 103}
 104
 105static inline int iskeychar(int c)
 106{
 107        return isalnum(c) || c == '-';
 108}
 109
 110static int get_value(config_fn_t fn, char *name, unsigned int len)
 111{
 112        int c;
 113        char *value;
 114
 115        /* Get the full name */
 116        for (;;) {
 117                c = get_next_char();
 118                if (c == EOF)
 119                        break;
 120                if (!iskeychar(c))
 121                        break;
 122                name[len++] = tolower(c);
 123                if (len >= MAXNAME)
 124                        return -1;
 125        }
 126        name[len] = 0;
 127        while (c == ' ' || c == '\t')
 128                c = get_next_char();
 129
 130        value = NULL;
 131        if (c != '\n') {
 132                if (c != '=')
 133                        return -1;
 134                value = parse_value();
 135                if (!value)
 136                        return -1;
 137        }
 138        return fn(name, value);
 139}
 140
 141static int get_extended_base_var(char *name, int baselen, int c)
 142{
 143        do {
 144                if (c == '\n')
 145                        return -1;
 146                c = get_next_char();
 147        } while (isspace(c));
 148
 149        /* We require the format to be '[base "extension"]' */
 150        if (c != '"')
 151                return -1;
 152        name[baselen++] = '.';
 153
 154        for (;;) {
 155                int c = get_next_char();
 156                if (c == '\n')
 157                        return -1;
 158                if (c == '"')
 159                        break;
 160                if (c == '\\') {
 161                        c = get_next_char();
 162                        if (c == '\n')
 163                                return -1;
 164                }
 165                name[baselen++] = c;
 166                if (baselen > MAXNAME / 2)
 167                        return -1;
 168        }
 169
 170        /* Final ']' */
 171        if (get_next_char() != ']')
 172                return -1;
 173        return baselen;
 174}
 175
 176static int get_base_var(char *name)
 177{
 178        int baselen = 0;
 179
 180        for (;;) {
 181                int c = get_next_char();
 182                if (c == EOF)
 183                        return -1;
 184                if (c == ']')
 185                        return baselen;
 186                if (isspace(c))
 187                        return get_extended_base_var(name, baselen, c);
 188                if (!iskeychar(c) && c != '.')
 189                        return -1;
 190                if (baselen > MAXNAME / 2)
 191                        return -1;
 192                name[baselen++] = tolower(c);
 193        }
 194}
 195
 196static int git_parse_file(config_fn_t fn)
 197{
 198        int comment = 0;
 199        int baselen = 0;
 200        static char var[MAXNAME];
 201
 202        for (;;) {
 203                int c = get_next_char();
 204                if (c == '\n') {
 205                        /* EOF? */
 206                        if (!config_file)
 207                                return 0;
 208                        comment = 0;
 209                        continue;
 210                }
 211                if (comment || isspace(c))
 212                        continue;
 213                if (c == '#' || c == ';') {
 214                        comment = 1;
 215                        continue;
 216                }
 217                if (c == '[') {
 218                        baselen = get_base_var(var);
 219                        if (baselen <= 0)
 220                                break;
 221                        var[baselen++] = '.';
 222                        var[baselen] = 0;
 223                        continue;
 224                }
 225                if (!isalpha(c))
 226                        break;
 227                var[baselen] = tolower(c);
 228                if (get_value(fn, var, baselen+1) < 0)
 229                        break;
 230        }
 231        die("bad config file line %d in %s", config_linenr, config_file_name);
 232}
 233
 234int git_config_int(const char *name, const char *value)
 235{
 236        if (value && *value) {
 237                char *end;
 238                int val = strtol(value, &end, 0);
 239                if (!*end)
 240                        return val;
 241                if (!strcasecmp(end, "k"))
 242                        return val * 1024;
 243                if (!strcasecmp(end, "m"))
 244                        return val * 1024 * 1024;
 245                if (!strcasecmp(end, "g"))
 246                        return val * 1024 * 1024 * 1024;
 247        }
 248        die("bad config value for '%s' in %s", name, config_file_name);
 249}
 250
 251int git_config_bool(const char *name, const char *value)
 252{
 253        if (!value)
 254                return 1;
 255        if (!*value)
 256                return 0;
 257        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 258                return 1;
 259        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 260                return 0;
 261        return git_config_int(name, value) != 0;
 262}
 263
 264int git_default_config(const char *var, const char *value)
 265{
 266        /* This needs a better name */
 267        if (!strcmp(var, "core.filemode")) {
 268                trust_executable_bit = git_config_bool(var, value);
 269                return 0;
 270        }
 271
 272        if (!strcmp(var, "core.bare")) {
 273                is_bare_repository_cfg = git_config_bool(var, value);
 274                return 0;
 275        }
 276
 277        if (!strcmp(var, "core.ignorestat")) {
 278                assume_unchanged = git_config_bool(var, value);
 279                return 0;
 280        }
 281
 282        if (!strcmp(var, "core.prefersymlinkrefs")) {
 283                prefer_symlink_refs = git_config_bool(var, value);
 284                return 0;
 285        }
 286
 287        if (!strcmp(var, "core.logallrefupdates")) {
 288                log_all_ref_updates = git_config_bool(var, value);
 289                return 0;
 290        }
 291
 292        if (!strcmp(var, "core.warnambiguousrefs")) {
 293                warn_ambiguous_refs = git_config_bool(var, value);
 294                return 0;
 295        }
 296
 297        if (!strcmp(var, "core.legacyheaders")) {
 298                use_legacy_headers = git_config_bool(var, value);
 299                return 0;
 300        }
 301
 302        if (!strcmp(var, "core.compression")) {
 303                int level = git_config_int(var, value);
 304                if (level == -1)
 305                        level = Z_DEFAULT_COMPRESSION;
 306                else if (level < 0 || level > Z_BEST_COMPRESSION)
 307                        die("bad zlib compression level %d", level);
 308                zlib_compression_level = level;
 309                return 0;
 310        }
 311
 312        if (!strcmp(var, "core.packedgitwindowsize")) {
 313                int pgsz_x2 = getpagesize() * 2;
 314                packed_git_window_size = git_config_int(var, value);
 315
 316                /* This value must be multiple of (pagesize * 2) */
 317                packed_git_window_size /= pgsz_x2;
 318                if (packed_git_window_size < 1)
 319                        packed_git_window_size = 1;
 320                packed_git_window_size *= pgsz_x2;
 321                return 0;
 322        }
 323
 324        if (!strcmp(var, "core.packedgitlimit")) {
 325                packed_git_limit = git_config_int(var, value);
 326                return 0;
 327        }
 328
 329        if (!strcmp(var, "core.autocrlf")) {
 330                if (value && !strcasecmp(value, "input")) {
 331                        auto_crlf = -1;
 332                        return 0;
 333                }
 334                auto_crlf = git_config_bool(var, value);
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "user.name")) {
 339                strlcpy(git_default_name, value, sizeof(git_default_name));
 340                return 0;
 341        }
 342
 343        if (!strcmp(var, "user.email")) {
 344                strlcpy(git_default_email, value, sizeof(git_default_email));
 345                return 0;
 346        }
 347
 348        if (!strcmp(var, "i18n.commitencoding")) {
 349                git_commit_encoding = strdup(value);
 350                return 0;
 351        }
 352
 353        if (!strcmp(var, "i18n.logoutputencoding")) {
 354                git_log_output_encoding = strdup(value);
 355                return 0;
 356        }
 357
 358
 359        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 360                pager_use_color = git_config_bool(var,value);
 361                return 0;
 362        }
 363
 364        /* Add other config variables here and to Documentation/config.txt. */
 365        return 0;
 366}
 367
 368int git_config_from_file(config_fn_t fn, const char *filename)
 369{
 370        int ret;
 371        FILE *f = fopen(filename, "r");
 372
 373        ret = -1;
 374        if (f) {
 375                config_file = f;
 376                config_file_name = filename;
 377                config_linenr = 1;
 378                ret = git_parse_file(fn);
 379                fclose(f);
 380                config_file_name = NULL;
 381        }
 382        return ret;
 383}
 384
 385int git_config(config_fn_t fn)
 386{
 387        int ret = 0;
 388        char *repo_config = NULL;
 389        const char *home = NULL, *filename;
 390
 391        /* $GIT_CONFIG makes git read _only_ the given config file,
 392         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 393         * global config file, the same way it would the per-repository
 394         * config file otherwise. */
 395        filename = getenv(CONFIG_ENVIRONMENT);
 396        if (!filename) {
 397                home = getenv("HOME");
 398                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 399                if (!filename)
 400                        filename = repo_config = xstrdup(git_path("config"));
 401        }
 402
 403        if (home) {
 404                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 405                if (!access(user_config, R_OK))
 406                        ret = git_config_from_file(fn, user_config);
 407                free(user_config);
 408        }
 409
 410        ret += git_config_from_file(fn, filename);
 411        free(repo_config);
 412        return ret;
 413}
 414
 415/*
 416 * Find all the stuff for git_config_set() below.
 417 */
 418
 419#define MAX_MATCHES 512
 420
 421static struct {
 422        int baselen;
 423        char* key;
 424        int do_not_match;
 425        regex_t* value_regex;
 426        int multi_replace;
 427        off_t offset[MAX_MATCHES];
 428        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 429        int seen;
 430} store;
 431
 432static int matches(const char* key, const char* value)
 433{
 434        return !strcmp(key, store.key) &&
 435                (store.value_regex == NULL ||
 436                 (store.do_not_match ^
 437                  !regexec(store.value_regex, value, 0, NULL, 0)));
 438}
 439
 440static int store_aux(const char* key, const char* value)
 441{
 442        switch (store.state) {
 443        case KEY_SEEN:
 444                if (matches(key, value)) {
 445                        if (store.seen == 1 && store.multi_replace == 0) {
 446                                fprintf(stderr,
 447                                        "Warning: %s has multiple values\n",
 448                                        key);
 449                        } else if (store.seen >= MAX_MATCHES) {
 450                                fprintf(stderr, "Too many matches\n");
 451                                return 1;
 452                        }
 453
 454                        store.offset[store.seen] = ftell(config_file);
 455                        store.seen++;
 456                }
 457                break;
 458        case SECTION_SEEN:
 459                if (strncmp(key, store.key, store.baselen+1)) {
 460                        store.state = SECTION_END_SEEN;
 461                        break;
 462                } else
 463                        /* do not increment matches: this is no match */
 464                        store.offset[store.seen] = ftell(config_file);
 465                /* fallthru */
 466        case SECTION_END_SEEN:
 467        case START:
 468                if (matches(key, value)) {
 469                        store.offset[store.seen] = ftell(config_file);
 470                        store.state = KEY_SEEN;
 471                        store.seen++;
 472                } else {
 473                        if (strrchr(key, '.') - key == store.baselen &&
 474                              !strncmp(key, store.key, store.baselen)) {
 475                                        store.state = SECTION_SEEN;
 476                                        store.offset[store.seen] = ftell(config_file);
 477                        }
 478                }
 479        }
 480        return 0;
 481}
 482
 483static int write_error()
 484{
 485        fprintf(stderr, "Failed to write new configuration file\n");
 486
 487        /* Same error code as "failed to rename". */
 488        return 4;
 489}
 490
 491static int store_write_section(int fd, const char* key)
 492{
 493        const char *dot = strchr(key, '.');
 494        int len1 = store.baselen, len2 = -1;
 495
 496        dot = strchr(key, '.');
 497        if (dot) {
 498                int dotlen = dot - key;
 499                if (dotlen < len1) {
 500                        len2 = len1 - dotlen - 1;
 501                        len1 = dotlen;
 502                }
 503        }
 504
 505        if (write_in_full(fd, "[", 1) != 1 ||
 506            write_in_full(fd, key, len1) != len1)
 507                return 0;
 508        if (len2 >= 0) {
 509                if (write_in_full(fd, " \"", 2) != 2)
 510                        return 0;
 511                while (--len2 >= 0) {
 512                        unsigned char c = *++dot;
 513                        if (c == '"')
 514                                if (write_in_full(fd, "\\", 1) != 1)
 515                                        return 0;
 516                        if (write_in_full(fd, &c, 1) != 1)
 517                                return 0;
 518                }
 519                if (write_in_full(fd, "\"", 1) != 1)
 520                        return 0;
 521        }
 522        if (write_in_full(fd, "]\n", 2) != 2)
 523                return 0;
 524
 525        return 1;
 526}
 527
 528static int store_write_pair(int fd, const char* key, const char* value)
 529{
 530        int i;
 531        int length = strlen(key+store.baselen+1);
 532        int quote = 0;
 533
 534        /* Check to see if the value needs to be quoted. */
 535        if (value[0] == ' ')
 536                quote = 1;
 537        for (i = 0; value[i]; i++)
 538                if (value[i] == ';' || value[i] == '#')
 539                        quote = 1;
 540        if (value[i-1] == ' ')
 541                quote = 1;
 542
 543        if (write_in_full(fd, "\t", 1) != 1 ||
 544            write_in_full(fd, key+store.baselen+1, length) != length ||
 545            write_in_full(fd, " = ", 3) != 3)
 546                return 0;
 547        if (quote && write_in_full(fd, "\"", 1) != 1)
 548                return 0;
 549        for (i = 0; value[i]; i++)
 550                switch (value[i]) {
 551                case '\n':
 552                        if (write_in_full(fd, "\\n", 2) != 2)
 553                                return 0;
 554                        break;
 555                case '\t':
 556                        if (write_in_full(fd, "\\t", 2) != 2)
 557                                return 0;
 558                        break;
 559                case '"':
 560                case '\\':
 561                        if (write_in_full(fd, "\\", 1) != 1)
 562                                return 0;
 563                default:
 564                        if (write_in_full(fd, value+i, 1) != 1)
 565                                return 0;
 566                        break;
 567                }
 568        if (quote && write_in_full(fd, "\"", 1) != 1)
 569                return 0;
 570        if (write_in_full(fd, "\n", 1) != 1)
 571                return 0;
 572        return 1;
 573}
 574
 575static int find_beginning_of_line(const char* contents, int size,
 576        int offset_, int* found_bracket)
 577{
 578        int equal_offset = size, bracket_offset = size;
 579        int offset;
 580
 581        for (offset = offset_-2; offset > 0 
 582                        && contents[offset] != '\n'; offset--)
 583                switch (contents[offset]) {
 584                        case '=': equal_offset = offset; break;
 585                        case ']': bracket_offset = offset; break;
 586                }
 587        if (bracket_offset < equal_offset) {
 588                *found_bracket = 1;
 589                offset = bracket_offset+1;
 590        } else
 591                offset++;
 592
 593        return offset;
 594}
 595
 596int git_config_set(const char* key, const char* value)
 597{
 598        return git_config_set_multivar(key, value, NULL, 0);
 599}
 600
 601/*
 602 * If value==NULL, unset in (remove from) config,
 603 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 604 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 605 *     else all matching key/values (regardless how many) are removed,
 606 *     before the new pair is written.
 607 *
 608 * Returns 0 on success.
 609 *
 610 * This function does this:
 611 *
 612 * - it locks the config file by creating ".git/config.lock"
 613 *
 614 * - it then parses the config using store_aux() as validator to find
 615 *   the position on the key/value pair to replace. If it is to be unset,
 616 *   it must be found exactly once.
 617 *
 618 * - the config file is mmap()ed and the part before the match (if any) is
 619 *   written to the lock file, then the changed part and the rest.
 620 *
 621 * - the config file is removed and the lock file rename()d to it.
 622 *
 623 */
 624int git_config_set_multivar(const char* key, const char* value,
 625        const char* value_regex, int multi_replace)
 626{
 627        int i, dot;
 628        int fd = -1, in_fd;
 629        int ret;
 630        char* config_filename;
 631        char* lock_file;
 632        const char* last_dot = strrchr(key, '.');
 633
 634        config_filename = getenv(CONFIG_ENVIRONMENT);
 635        if (!config_filename) {
 636                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 637                if (!config_filename)
 638                        config_filename  = git_path("config");
 639        }
 640        config_filename = xstrdup(config_filename);
 641        lock_file = xstrdup(mkpath("%s.lock", config_filename));
 642
 643        /*
 644         * Since "key" actually contains the section name and the real
 645         * key name separated by a dot, we have to know where the dot is.
 646         */
 647
 648        if (last_dot == NULL) {
 649                fprintf(stderr, "key does not contain a section: %s\n", key);
 650                ret = 2;
 651                goto out_free;
 652        }
 653        store.baselen = last_dot - key;
 654
 655        store.multi_replace = multi_replace;
 656
 657        /*
 658         * Validate the key and while at it, lower case it for matching.
 659         */
 660        store.key = xmalloc(strlen(key) + 1);
 661        dot = 0;
 662        for (i = 0; key[i]; i++) {
 663                unsigned char c = key[i];
 664                if (c == '.')
 665                        dot = 1;
 666                /* Leave the extended basename untouched.. */
 667                if (!dot || i > store.baselen) {
 668                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 669                                fprintf(stderr, "invalid key: %s\n", key);
 670                                free(store.key);
 671                                ret = 1;
 672                                goto out_free;
 673                        }
 674                        c = tolower(c);
 675                } else if (c == '\n') {
 676                        fprintf(stderr, "invalid key (newline): %s\n", key);
 677                        free(store.key);
 678                        ret = 1;
 679                        goto out_free;
 680                }
 681                store.key[i] = c;
 682        }
 683        store.key[i] = 0;
 684
 685        /*
 686         * The lock_file serves a purpose in addition to locking: the new
 687         * contents of .git/config will be written into it.
 688         */
 689        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 690        if (fd < 0 || adjust_shared_perm(lock_file)) {
 691                fprintf(stderr, "could not lock config file\n");
 692                free(store.key);
 693                ret = -1;
 694                goto out_free;
 695        }
 696
 697        /*
 698         * If .git/config does not exist yet, write a minimal version.
 699         */
 700        in_fd = open(config_filename, O_RDONLY);
 701        if ( in_fd < 0 ) {
 702                free(store.key);
 703
 704                if ( ENOENT != errno ) {
 705                        error("opening %s: %s", config_filename,
 706                              strerror(errno));
 707                        ret = 3; /* same as "invalid config file" */
 708                        goto out_free;
 709                }
 710                /* if nothing to unset, error out */
 711                if (value == NULL) {
 712                        ret = 5;
 713                        goto out_free;
 714                }
 715
 716                store.key = (char*)key;
 717                if (!store_write_section(fd, key) ||
 718                    !store_write_pair(fd, key, value))
 719                        goto write_err_out;
 720        } else {
 721                struct stat st;
 722                char* contents;
 723                int i, copy_begin, copy_end, new_line = 0;
 724
 725                if (value_regex == NULL)
 726                        store.value_regex = NULL;
 727                else {
 728                        if (value_regex[0] == '!') {
 729                                store.do_not_match = 1;
 730                                value_regex++;
 731                        } else
 732                                store.do_not_match = 0;
 733
 734                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 735                        if (regcomp(store.value_regex, value_regex,
 736                                        REG_EXTENDED)) {
 737                                fprintf(stderr, "Invalid pattern: %s\n",
 738                                        value_regex);
 739                                free(store.value_regex);
 740                                ret = 6;
 741                                goto out_free;
 742                        }
 743                }
 744
 745                store.offset[0] = 0;
 746                store.state = START;
 747                store.seen = 0;
 748
 749                /*
 750                 * After this, store.offset will contain the *end* offset
 751                 * of the last match, or remain at 0 if no match was found.
 752                 * As a side effect, we make sure to transform only a valid
 753                 * existing config file.
 754                 */
 755                if (git_config_from_file(store_aux, config_filename)) {
 756                        fprintf(stderr, "invalid config file\n");
 757                        free(store.key);
 758                        if (store.value_regex != NULL) {
 759                                regfree(store.value_regex);
 760                                free(store.value_regex);
 761                        }
 762                        ret = 3;
 763                        goto out_free;
 764                }
 765
 766                free(store.key);
 767                if (store.value_regex != NULL) {
 768                        regfree(store.value_regex);
 769                        free(store.value_regex);
 770                }
 771
 772                /* if nothing to unset, or too many matches, error out */
 773                if ((store.seen == 0 && value == NULL) ||
 774                                (store.seen > 1 && multi_replace == 0)) {
 775                        ret = 5;
 776                        goto out_free;
 777                }
 778
 779                fstat(in_fd, &st);
 780                contents = xmmap(NULL, st.st_size, PROT_READ,
 781                        MAP_PRIVATE, in_fd, 0);
 782                close(in_fd);
 783
 784                if (store.seen == 0)
 785                        store.seen = 1;
 786
 787                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 788                        if (store.offset[i] == 0) {
 789                                store.offset[i] = copy_end = st.st_size;
 790                        } else if (store.state != KEY_SEEN) {
 791                                copy_end = store.offset[i];
 792                        } else
 793                                copy_end = find_beginning_of_line(
 794                                        contents, st.st_size,
 795                                        store.offset[i]-2, &new_line);
 796
 797                        /* write the first part of the config */
 798                        if (copy_end > copy_begin) {
 799                                if (write_in_full(fd, contents + copy_begin,
 800                                                  copy_end - copy_begin) <
 801                                    copy_end - copy_begin)
 802                                        goto write_err_out;
 803                                if (new_line &&
 804                                    write_in_full(fd, "\n", 1) != 1)
 805                                        goto write_err_out;
 806                        }
 807                        copy_begin = store.offset[i];
 808                }
 809
 810                /* write the pair (value == NULL means unset) */
 811                if (value != NULL) {
 812                        if (store.state == START) {
 813                                if (!store_write_section(fd, key))
 814                                        goto write_err_out;
 815                        }
 816                        if (!store_write_pair(fd, key, value))
 817                                goto write_err_out;
 818                }
 819
 820                /* write the rest of the config */
 821                if (copy_begin < st.st_size)
 822                        if (write_in_full(fd, contents + copy_begin,
 823                                          st.st_size - copy_begin) <
 824                            st.st_size - copy_begin)
 825                                goto write_err_out;
 826
 827                munmap(contents, st.st_size);
 828                unlink(config_filename);
 829        }
 830
 831        if (rename(lock_file, config_filename) < 0) {
 832                fprintf(stderr, "Could not rename the lock file?\n");
 833                ret = 4;
 834                goto out_free;
 835        }
 836
 837        ret = 0;
 838
 839out_free:
 840        if (0 <= fd)
 841                close(fd);
 842        free(config_filename);
 843        if (lock_file) {
 844                unlink(lock_file);
 845                free(lock_file);
 846        }
 847        return ret;
 848
 849write_err_out:
 850        ret = write_error();
 851        goto out_free;
 852
 853}
 854
 855int git_config_rename_section(const char *old_name, const char *new_name)
 856{
 857        int ret = 0;
 858        char *config_filename;
 859        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
 860        int out_fd;
 861        char buf[1024];
 862
 863        config_filename = getenv(CONFIG_ENVIRONMENT);
 864        if (!config_filename) {
 865                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 866                if (!config_filename)
 867                        config_filename  = git_path("config");
 868        }
 869        config_filename = xstrdup(config_filename);
 870        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
 871        if (out_fd < 0) {
 872                ret = error("Could not lock config file!");
 873                goto out;
 874        }
 875
 876        if (!(config_file = fopen(config_filename, "rb"))) {
 877                ret = error("Could not open config file!");
 878                goto out;
 879        }
 880
 881        while (fgets(buf, sizeof(buf), config_file)) {
 882                int i;
 883                int length;
 884                for (i = 0; buf[i] && isspace(buf[i]); i++)
 885                        ; /* do nothing */
 886                if (buf[i] == '[') {
 887                        /* it's a section */
 888                        int j = 0, dot = 0;
 889                        for (i++; buf[i] && buf[i] != ']'; i++) {
 890                                if (!dot && isspace(buf[i])) {
 891                                        dot = 1;
 892                                        if (old_name[j++] != '.')
 893                                                break;
 894                                        for (i++; isspace(buf[i]); i++)
 895                                                ; /* do nothing */
 896                                        if (buf[i] != '"')
 897                                                break;
 898                                        continue;
 899                                }
 900                                if (buf[i] == '\\' && dot)
 901                                        i++;
 902                                else if (buf[i] == '"' && dot) {
 903                                        for (i++; isspace(buf[i]); i++)
 904                                                ; /* do_nothing */
 905                                        break;
 906                                }
 907                                if (buf[i] != old_name[j++])
 908                                        break;
 909                        }
 910                        if (buf[i] == ']' && old_name[j] == 0) {
 911                                /* old_name matches */
 912                                ret++;
 913                                store.baselen = strlen(new_name);
 914                                if (!store_write_section(out_fd, new_name)) {
 915                                        ret = write_error();
 916                                        goto out;
 917                                }
 918                                continue;
 919                        }
 920                }
 921                length = strlen(buf);
 922                if (write_in_full(out_fd, buf, length) != length) {
 923                        ret = write_error();
 924                        goto out;
 925                }
 926        }
 927        fclose(config_file);
 928        if (close(out_fd) || commit_lock_file(lock) < 0)
 929                        ret = error("Cannot commit config file!");
 930 out:
 931        free(config_filename);
 932        return ret;
 933}
 934