Andrew's git / gitweb.git / config.c
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config.con commit Add test-chmtime: a utility to change mtime on files (17e4836)
   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                if (!access(ETC_GITCONFIG, R_OK))
 398                        ret += git_config_from_file(fn, ETC_GITCONFIG);
 399                home = getenv("HOME");
 400                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 401                if (!filename)
 402                        filename = repo_config = xstrdup(git_path("config"));
 403        }
 404
 405        if (home) {
 406                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 407                if (!access(user_config, R_OK))
 408                        ret = git_config_from_file(fn, user_config);
 409                free(user_config);
 410        }
 411
 412        ret += git_config_from_file(fn, filename);
 413        free(repo_config);
 414        return ret;
 415}
 416
 417/*
 418 * Find all the stuff for git_config_set() below.
 419 */
 420
 421#define MAX_MATCHES 512
 422
 423static struct {
 424        int baselen;
 425        char* key;
 426        int do_not_match;
 427        regex_t* value_regex;
 428        int multi_replace;
 429        off_t offset[MAX_MATCHES];
 430        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 431        int seen;
 432} store;
 433
 434static int matches(const char* key, const char* value)
 435{
 436        return !strcmp(key, store.key) &&
 437                (store.value_regex == NULL ||
 438                 (store.do_not_match ^
 439                  !regexec(store.value_regex, value, 0, NULL, 0)));
 440}
 441
 442static int store_aux(const char* key, const char* value)
 443{
 444        switch (store.state) {
 445        case KEY_SEEN:
 446                if (matches(key, value)) {
 447                        if (store.seen == 1 && store.multi_replace == 0) {
 448                                fprintf(stderr,
 449                                        "Warning: %s has multiple values\n",
 450                                        key);
 451                        } else if (store.seen >= MAX_MATCHES) {
 452                                fprintf(stderr, "Too many matches\n");
 453                                return 1;
 454                        }
 455
 456                        store.offset[store.seen] = ftell(config_file);
 457                        store.seen++;
 458                }
 459                break;
 460        case SECTION_SEEN:
 461                if (strncmp(key, store.key, store.baselen+1)) {
 462                        store.state = SECTION_END_SEEN;
 463                        break;
 464                } else
 465                        /* do not increment matches: this is no match */
 466                        store.offset[store.seen] = ftell(config_file);
 467                /* fallthru */
 468        case SECTION_END_SEEN:
 469        case START:
 470                if (matches(key, value)) {
 471                        store.offset[store.seen] = ftell(config_file);
 472                        store.state = KEY_SEEN;
 473                        store.seen++;
 474                } else {
 475                        if (strrchr(key, '.') - key == store.baselen &&
 476                              !strncmp(key, store.key, store.baselen)) {
 477                                        store.state = SECTION_SEEN;
 478                                        store.offset[store.seen] = ftell(config_file);
 479                        }
 480                }
 481        }
 482        return 0;
 483}
 484
 485static int write_error()
 486{
 487        fprintf(stderr, "Failed to write new configuration file\n");
 488
 489        /* Same error code as "failed to rename". */
 490        return 4;
 491}
 492
 493static int store_write_section(int fd, const char* key)
 494{
 495        const char *dot = strchr(key, '.');
 496        int len1 = store.baselen, len2 = -1;
 497
 498        dot = strchr(key, '.');
 499        if (dot) {
 500                int dotlen = dot - key;
 501                if (dotlen < len1) {
 502                        len2 = len1 - dotlen - 1;
 503                        len1 = dotlen;
 504                }
 505        }
 506
 507        if (write_in_full(fd, "[", 1) != 1 ||
 508            write_in_full(fd, key, len1) != len1)
 509                return 0;
 510        if (len2 >= 0) {
 511                if (write_in_full(fd, " \"", 2) != 2)
 512                        return 0;
 513                while (--len2 >= 0) {
 514                        unsigned char c = *++dot;
 515                        if (c == '"')
 516                                if (write_in_full(fd, "\\", 1) != 1)
 517                                        return 0;
 518                        if (write_in_full(fd, &c, 1) != 1)
 519                                return 0;
 520                }
 521                if (write_in_full(fd, "\"", 1) != 1)
 522                        return 0;
 523        }
 524        if (write_in_full(fd, "]\n", 2) != 2)
 525                return 0;
 526
 527        return 1;
 528}
 529
 530static int store_write_pair(int fd, const char* key, const char* value)
 531{
 532        int i;
 533        int length = strlen(key+store.baselen+1);
 534        int quote = 0;
 535
 536        /* Check to see if the value needs to be quoted. */
 537        if (value[0] == ' ')
 538                quote = 1;
 539        for (i = 0; value[i]; i++)
 540                if (value[i] == ';' || value[i] == '#')
 541                        quote = 1;
 542        if (value[i-1] == ' ')
 543                quote = 1;
 544
 545        if (write_in_full(fd, "\t", 1) != 1 ||
 546            write_in_full(fd, key+store.baselen+1, length) != length ||
 547            write_in_full(fd, " = ", 3) != 3)
 548                return 0;
 549        if (quote && write_in_full(fd, "\"", 1) != 1)
 550                return 0;
 551        for (i = 0; value[i]; i++)
 552                switch (value[i]) {
 553                case '\n':
 554                        if (write_in_full(fd, "\\n", 2) != 2)
 555                                return 0;
 556                        break;
 557                case '\t':
 558                        if (write_in_full(fd, "\\t", 2) != 2)
 559                                return 0;
 560                        break;
 561                case '"':
 562                case '\\':
 563                        if (write_in_full(fd, "\\", 1) != 1)
 564                                return 0;
 565                default:
 566                        if (write_in_full(fd, value+i, 1) != 1)
 567                                return 0;
 568                        break;
 569                }
 570        if (quote && write_in_full(fd, "\"", 1) != 1)
 571                return 0;
 572        if (write_in_full(fd, "\n", 1) != 1)
 573                return 0;
 574        return 1;
 575}
 576
 577static int find_beginning_of_line(const char* contents, int size,
 578        int offset_, int* found_bracket)
 579{
 580        int equal_offset = size, bracket_offset = size;
 581        int offset;
 582
 583        for (offset = offset_-2; offset > 0 
 584                        && contents[offset] != '\n'; offset--)
 585                switch (contents[offset]) {
 586                        case '=': equal_offset = offset; break;
 587                        case ']': bracket_offset = offset; break;
 588                }
 589        if (bracket_offset < equal_offset) {
 590                *found_bracket = 1;
 591                offset = bracket_offset+1;
 592        } else
 593                offset++;
 594
 595        return offset;
 596}
 597
 598int git_config_set(const char* key, const char* value)
 599{
 600        return git_config_set_multivar(key, value, NULL, 0);
 601}
 602
 603/*
 604 * If value==NULL, unset in (remove from) config,
 605 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 606 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 607 *     else all matching key/values (regardless how many) are removed,
 608 *     before the new pair is written.
 609 *
 610 * Returns 0 on success.
 611 *
 612 * This function does this:
 613 *
 614 * - it locks the config file by creating ".git/config.lock"
 615 *
 616 * - it then parses the config using store_aux() as validator to find
 617 *   the position on the key/value pair to replace. If it is to be unset,
 618 *   it must be found exactly once.
 619 *
 620 * - the config file is mmap()ed and the part before the match (if any) is
 621 *   written to the lock file, then the changed part and the rest.
 622 *
 623 * - the config file is removed and the lock file rename()d to it.
 624 *
 625 */
 626int git_config_set_multivar(const char* key, const char* value,
 627        const char* value_regex, int multi_replace)
 628{
 629        int i, dot;
 630        int fd = -1, in_fd;
 631        int ret;
 632        char* config_filename;
 633        char* lock_file;
 634        const char* last_dot = strrchr(key, '.');
 635
 636        config_filename = getenv(CONFIG_ENVIRONMENT);
 637        if (!config_filename) {
 638                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 639                if (!config_filename)
 640                        config_filename  = git_path("config");
 641        }
 642        config_filename = xstrdup(config_filename);
 643        lock_file = xstrdup(mkpath("%s.lock", config_filename));
 644
 645        /*
 646         * Since "key" actually contains the section name and the real
 647         * key name separated by a dot, we have to know where the dot is.
 648         */
 649
 650        if (last_dot == NULL) {
 651                fprintf(stderr, "key does not contain a section: %s\n", key);
 652                ret = 2;
 653                goto out_free;
 654        }
 655        store.baselen = last_dot - key;
 656
 657        store.multi_replace = multi_replace;
 658
 659        /*
 660         * Validate the key and while at it, lower case it for matching.
 661         */
 662        store.key = xmalloc(strlen(key) + 1);
 663        dot = 0;
 664        for (i = 0; key[i]; i++) {
 665                unsigned char c = key[i];
 666                if (c == '.')
 667                        dot = 1;
 668                /* Leave the extended basename untouched.. */
 669                if (!dot || i > store.baselen) {
 670                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 671                                fprintf(stderr, "invalid key: %s\n", key);
 672                                free(store.key);
 673                                ret = 1;
 674                                goto out_free;
 675                        }
 676                        c = tolower(c);
 677                } else if (c == '\n') {
 678                        fprintf(stderr, "invalid key (newline): %s\n", key);
 679                        free(store.key);
 680                        ret = 1;
 681                        goto out_free;
 682                }
 683                store.key[i] = c;
 684        }
 685        store.key[i] = 0;
 686
 687        /*
 688         * The lock_file serves a purpose in addition to locking: the new
 689         * contents of .git/config will be written into it.
 690         */
 691        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 692        if (fd < 0 || adjust_shared_perm(lock_file)) {
 693                fprintf(stderr, "could not lock config file\n");
 694                free(store.key);
 695                ret = -1;
 696                goto out_free;
 697        }
 698
 699        /*
 700         * If .git/config does not exist yet, write a minimal version.
 701         */
 702        in_fd = open(config_filename, O_RDONLY);
 703        if ( in_fd < 0 ) {
 704                free(store.key);
 705
 706                if ( ENOENT != errno ) {
 707                        error("opening %s: %s", config_filename,
 708                              strerror(errno));
 709                        ret = 3; /* same as "invalid config file" */
 710                        goto out_free;
 711                }
 712                /* if nothing to unset, error out */
 713                if (value == NULL) {
 714                        ret = 5;
 715                        goto out_free;
 716                }
 717
 718                store.key = (char*)key;
 719                if (!store_write_section(fd, key) ||
 720                    !store_write_pair(fd, key, value))
 721                        goto write_err_out;
 722        } else {
 723                struct stat st;
 724                char* contents;
 725                int i, copy_begin, copy_end, new_line = 0;
 726
 727                if (value_regex == NULL)
 728                        store.value_regex = NULL;
 729                else {
 730                        if (value_regex[0] == '!') {
 731                                store.do_not_match = 1;
 732                                value_regex++;
 733                        } else
 734                                store.do_not_match = 0;
 735
 736                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 737                        if (regcomp(store.value_regex, value_regex,
 738                                        REG_EXTENDED)) {
 739                                fprintf(stderr, "Invalid pattern: %s\n",
 740                                        value_regex);
 741                                free(store.value_regex);
 742                                ret = 6;
 743                                goto out_free;
 744                        }
 745                }
 746
 747                store.offset[0] = 0;
 748                store.state = START;
 749                store.seen = 0;
 750
 751                /*
 752                 * After this, store.offset will contain the *end* offset
 753                 * of the last match, or remain at 0 if no match was found.
 754                 * As a side effect, we make sure to transform only a valid
 755                 * existing config file.
 756                 */
 757                if (git_config_from_file(store_aux, config_filename)) {
 758                        fprintf(stderr, "invalid config file\n");
 759                        free(store.key);
 760                        if (store.value_regex != NULL) {
 761                                regfree(store.value_regex);
 762                                free(store.value_regex);
 763                        }
 764                        ret = 3;
 765                        goto out_free;
 766                }
 767
 768                free(store.key);
 769                if (store.value_regex != NULL) {
 770                        regfree(store.value_regex);
 771                        free(store.value_regex);
 772                }
 773
 774                /* if nothing to unset, or too many matches, error out */
 775                if ((store.seen == 0 && value == NULL) ||
 776                                (store.seen > 1 && multi_replace == 0)) {
 777                        ret = 5;
 778                        goto out_free;
 779                }
 780
 781                fstat(in_fd, &st);
 782                contents = xmmap(NULL, st.st_size, PROT_READ,
 783                        MAP_PRIVATE, in_fd, 0);
 784                close(in_fd);
 785
 786                if (store.seen == 0)
 787                        store.seen = 1;
 788
 789                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 790                        if (store.offset[i] == 0) {
 791                                store.offset[i] = copy_end = st.st_size;
 792                        } else if (store.state != KEY_SEEN) {
 793                                copy_end = store.offset[i];
 794                        } else
 795                                copy_end = find_beginning_of_line(
 796                                        contents, st.st_size,
 797                                        store.offset[i]-2, &new_line);
 798
 799                        /* write the first part of the config */
 800                        if (copy_end > copy_begin) {
 801                                if (write_in_full(fd, contents + copy_begin,
 802                                                  copy_end - copy_begin) <
 803                                    copy_end - copy_begin)
 804                                        goto write_err_out;
 805                                if (new_line &&
 806                                    write_in_full(fd, "\n", 1) != 1)
 807                                        goto write_err_out;
 808                        }
 809                        copy_begin = store.offset[i];
 810                }
 811
 812                /* write the pair (value == NULL means unset) */
 813                if (value != NULL) {
 814                        if (store.state == START) {
 815                                if (!store_write_section(fd, key))
 816                                        goto write_err_out;
 817                        }
 818                        if (!store_write_pair(fd, key, value))
 819                                goto write_err_out;
 820                }
 821
 822                /* write the rest of the config */
 823                if (copy_begin < st.st_size)
 824                        if (write_in_full(fd, contents + copy_begin,
 825                                          st.st_size - copy_begin) <
 826                            st.st_size - copy_begin)
 827                                goto write_err_out;
 828
 829                munmap(contents, st.st_size);
 830                unlink(config_filename);
 831        }
 832
 833        if (rename(lock_file, config_filename) < 0) {
 834                fprintf(stderr, "Could not rename the lock file?\n");
 835                ret = 4;
 836                goto out_free;
 837        }
 838
 839        ret = 0;
 840
 841out_free:
 842        if (0 <= fd)
 843                close(fd);
 844        free(config_filename);
 845        if (lock_file) {
 846                unlink(lock_file);
 847                free(lock_file);
 848        }
 849        return ret;
 850
 851write_err_out:
 852        ret = write_error();
 853        goto out_free;
 854
 855}
 856
 857int git_config_rename_section(const char *old_name, const char *new_name)
 858{
 859        int ret = 0;
 860        char *config_filename;
 861        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
 862        int out_fd;
 863        char buf[1024];
 864
 865        config_filename = getenv(CONFIG_ENVIRONMENT);
 866        if (!config_filename) {
 867                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 868                if (!config_filename)
 869                        config_filename  = git_path("config");
 870        }
 871        config_filename = xstrdup(config_filename);
 872        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
 873        if (out_fd < 0) {
 874                ret = error("Could not lock config file!");
 875                goto out;
 876        }
 877
 878        if (!(config_file = fopen(config_filename, "rb"))) {
 879                ret = error("Could not open config file!");
 880                goto out;
 881        }
 882
 883        while (fgets(buf, sizeof(buf), config_file)) {
 884                int i;
 885                int length;
 886                for (i = 0; buf[i] && isspace(buf[i]); i++)
 887                        ; /* do nothing */
 888                if (buf[i] == '[') {
 889                        /* it's a section */
 890                        int j = 0, dot = 0;
 891                        for (i++; buf[i] && buf[i] != ']'; i++) {
 892                                if (!dot && isspace(buf[i])) {
 893                                        dot = 1;
 894                                        if (old_name[j++] != '.')
 895                                                break;
 896                                        for (i++; isspace(buf[i]); i++)
 897                                                ; /* do nothing */
 898                                        if (buf[i] != '"')
 899                                                break;
 900                                        continue;
 901                                }
 902                                if (buf[i] == '\\' && dot)
 903                                        i++;
 904                                else if (buf[i] == '"' && dot) {
 905                                        for (i++; isspace(buf[i]); i++)
 906                                                ; /* do_nothing */
 907                                        break;
 908                                }
 909                                if (buf[i] != old_name[j++])
 910                                        break;
 911                        }
 912                        if (buf[i] == ']' && old_name[j] == 0) {
 913                                /* old_name matches */
 914                                ret++;
 915                                store.baselen = strlen(new_name);
 916                                if (!store_write_section(out_fd, new_name)) {
 917                                        ret = write_error();
 918                                        goto out;
 919                                }
 920                                continue;
 921                        }
 922                }
 923                length = strlen(buf);
 924                if (write_in_full(out_fd, buf, length) != length) {
 925                        ret = write_error();
 926                        goto out;
 927                }
 928        }
 929        fclose(config_file);
 930        if (close(out_fd) || commit_lock_file(lock) < 0)
 931                        ret = error("Cannot commit config file!");
 932 out:
 933        free(config_filename);
 934        return ret;
 935}
 936