config.c

   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 #include "exec_cmd.h"
  10 #include "strbuf.h"
  11 #include "quote.h"
  12
  13 struct config_source {
  14         struct config_source *prev;
  15         union {
  16                 FILE *file;
  17                 struct config_buf {
  18                         const char *buf;
  19                         size_t len;
  20                         size_t pos;
  21                 } buf;
  22         } u;
  23         const char *name;
  24         const char *path;
  25         int die_on_error;
  26         int linenr;
  27         int eof;
  28         struct strbuf value;
  29         struct strbuf var;
  30
  31         int (*do_fgetc)(struct config_source *c);
  32         int (*do_ungetc)(int c, struct config_source *conf);
  33         long (*do_ftell)(struct config_source *c);
  34 };
  35
  36 static struct config_source *cf;
  37
  38 static int zlib_compression_seen;
  39
  40 static int config_file_fgetc(struct config_source *conf)
  41 {
  42         return fgetc(conf->u.file);
  43 }
  44
  45 static int config_file_ungetc(int c, struct config_source *conf)
  46 {
  47         return ungetc(c, conf->u.file);
  48 }
  49
  50 static long config_file_ftell(struct config_source *conf)
  51 {
  52         return ftell(conf->u.file);
  53 }
  54
  55
  56 static int config_buf_fgetc(struct config_source *conf)
  57 {
  58         if (conf->u.buf.pos < conf->u.buf.len)
  59                 return conf->u.buf.buf[conf->u.buf.pos++];
  60
  61         return EOF;
  62 }
  63
  64 static int config_buf_ungetc(int c, struct config_source *conf)
  65 {
  66         if (conf->u.buf.pos > 0)
  67                 return conf->u.buf.buf[--conf->u.buf.pos];
  68
  69         return EOF;
  70 }
  71
  72 static long config_buf_ftell(struct config_source *conf)
  73 {
  74         return conf->u.buf.pos;
  75 }
  76
  77 #define MAX_INCLUDE_DEPTH 10
  78 static const char include_depth_advice[] =
  79 "exceeded maximum include depth (%d) while including\n"
  80 "       %s\n"
  81 "from\n"
  82 "       %s\n"
  83 "Do you have circular includes?";
  84 static int handle_path_include(const char *path, struct config_include_data *inc)
  85 {
  86         int ret = 0;
  87         struct strbuf buf = STRBUF_INIT;
  88         char *expanded;
  89
  90         if (!path)
  91                 return config_error_nonbool("include.path");
  92
  93         expanded = expand_user_path(path);
  94         if (!expanded)
  95                 return error("Could not expand include path '%s'", path);
  96         path = expanded;
  97
  98         /*
  99          * Use an absolute path as-is, but interpret relative paths
 100          * based on the including config file.
 101          */
 102         if (!is_absolute_path(path)) {
 103                 char *slash;
 104
 105                 if (!cf || !cf->path)
 106                         return error("relative config includes must come from files");
 107
 108                 slash = find_last_dir_sep(cf->path);
 109                 if (slash)
 110                         strbuf_add(&buf, cf->path, slash - cf->path + 1);
 111                 strbuf_addstr(&buf, path);
 112                 path = buf.buf;
 113         }
 114
 115         if (!access_or_die(path, R_OK, 0)) {
 116                 if (++inc->depth > MAX_INCLUDE_DEPTH)
 117                         die(include_depth_advice, MAX_INCLUDE_DEPTH, path,
 118                             cf && cf->name ? cf->name : "the command line");
 119                 ret = git_config_from_file(git_config_include, path, inc);
 120                 inc->depth--;
 121         }
 122         strbuf_release(&buf);
 123         free(expanded);
 124         return ret;
 125 }
 126
 127 int git_config_include(const char *var, const char *value, void *data)
 128 {
 129         struct config_include_data *inc = data;
 130         const char *type;
 131         int ret;
 132
 133         /*
 134          * Pass along all values, including "include" directives; this makes it
 135          * possible to query information on the includes themselves.
 136          */
 137         ret = inc->fn(var, value, inc->data);
 138         if (ret < 0)
 139                 return ret;
 140
 141         type = skip_prefix(var, "include.");
 142         if (!type)
 143                 return ret;
 144
 145         if (!strcmp(type, "path"))
 146                 ret = handle_path_include(value, inc);
 147         return ret;
 148 }
 149
 150 static void lowercase(char *p)
 151 {
 152         for (; *p; p++)
 153                 *p = tolower(*p);
 154 }
 155
 156 void git_config_push_parameter(const char *text)
 157 {
 158         struct strbuf env = STRBUF_INIT;
 159         const char *old = getenv(CONFIG_DATA_ENVIRONMENT);
 160         if (old) {
 161                 strbuf_addstr(&env, old);
 162                 strbuf_addch(&env, ' ');
 163         }
 164         sq_quote_buf(&env, text);
 165         setenv(CONFIG_DATA_ENVIRONMENT, env.buf, 1);
 166         strbuf_release(&env);
 167 }
 168
 169 int git_config_parse_parameter(const char *text,
 170                                config_fn_t fn, void *data)
 171 {
 172         struct strbuf **pair;
 173         pair = strbuf_split_str(text, '=', 2);
 174         if (!pair[0])
 175                 return error("bogus config parameter: %s", text);
 176         if (pair[0]->len && pair[0]->buf[pair[0]->len - 1] == '=')
 177                 strbuf_setlen(pair[0], pair[0]->len - 1);
 178         strbuf_trim(pair[0]);
 179         if (!pair[0]->len) {
 180                 strbuf_list_free(pair);
 181                 return error("bogus config parameter: %s", text);
 182         }
 183         lowercase(pair[0]->buf);
 184         if (fn(pair[0]->buf, pair[1] ? pair[1]->buf : NULL, data) < 0) {
 185                 strbuf_list_free(pair);
 186                 return -1;
 187         }
 188         strbuf_list_free(pair);
 189         return 0;
 190 }
 191
 192 int git_config_from_parameters(config_fn_t fn, void *data)
 193 {
 194         const char *env = getenv(CONFIG_DATA_ENVIRONMENT);
 195         char *envw;
 196         const char **argv = NULL;
 197         int nr = 0, alloc = 0;
 198         int i;
 199
 200         if (!env)
 201                 return 0;
 202         /* sq_dequote will write over it */
 203         envw = xstrdup(env);
 204
 205         if (sq_dequote_to_argv(envw, &argv, &nr, &alloc) < 0) {
 206                 free(envw);
 207                 return error("bogus format in " CONFIG_DATA_ENVIRONMENT);
 208         }
 209
 210         for (i = 0; i < nr; i++) {
 211                 if (git_config_parse_parameter(argv[i], fn, data) < 0) {
 212                         free(argv);
 213                         free(envw);
 214                         return -1;
 215                 }
 216         }
 217
 218         free(argv);
 219         free(envw);
 220         return nr > 0;
 221 }
 222
 223 static int get_next_char(void)
 224 {
 225         int c = cf->do_fgetc(cf);
 226
 227         if (c == '\r') {
 228                 /* DOS like systems */
 229                 c = cf->do_fgetc(cf);
 230                 if (c != '\n') {
 231                         cf->do_ungetc(c, cf);
 232                         c = '\r';
 233                 }
 234         }
 235         if (c == '\n')
 236                 cf->linenr++;
 237         if (c == EOF) {
 238                 cf->eof = 1;
 239                 c = '\n';
 240         }
 241         return c;
 242 }
 243
 244 static char *parse_value(void)
 245 {
 246         int quote = 0, comment = 0, space = 0;
 247
 248         strbuf_reset(&cf->value);
 249         for (;;) {
 250                 int c = get_next_char();
 251                 if (c == '\n') {
 252                         if (quote) {
 253                                 cf->linenr--;
 254                                 return NULL;
 255                         }
 256                         return cf->value.buf;
 257                 }
 258                 if (comment)
 259                         continue;
 260                 if (isspace(c) && !quote) {
 261                         if (cf->value.len)
 262                                 space++;
 263                         continue;
 264                 }
 265                 if (!quote) {
 266                         if (c == ';' || c == '#') {
 267                                 comment = 1;
 268                                 continue;
 269                         }
 270                 }
 271                 for (; space; space--)
 272                         strbuf_addch(&cf->value, ' ');
 273                 if (c == '\\') {
 274                         c = get_next_char();
 275                         switch (c) {
 276                         case '\n':
 277                                 continue;
 278                         case 't':
 279                                 c = '\t';
 280                                 break;
 281                         case 'b':
 282                                 c = '\b';
 283                                 break;
 284                         case 'n':
 285                                 c = '\n';
 286                                 break;
 287                         /* Some characters escape as themselves */
 288                         case '\\': case '"':
 289                                 break;
 290                         /* Reject unknown escape sequences */
 291                         default:
 292                                 return NULL;
 293                         }
 294                         strbuf_addch(&cf->value, c);
 295                         continue;
 296                 }
 297                 if (c == '"') {
 298                         quote = 1-quote;
 299                         continue;
 300                 }
 301                 strbuf_addch(&cf->value, c);
 302         }
 303 }
 304
 305 static inline int iskeychar(int c)
 306 {
 307         return isalnum(c) || c == '-';
 308 }
 309
 310 static int get_value(config_fn_t fn, void *data, struct strbuf *name)
 311 {
 312         int c;
 313         char *value;
 314
 315         /* Get the full name */
 316         for (;;) {
 317                 c = get_next_char();
 318                 if (cf->eof)
 319                         break;
 320                 if (!iskeychar(c))
 321                         break;
 322                 strbuf_addch(name, tolower(c));
 323         }
 324
 325         while (c == ' ' || c == '\t')
 326                 c = get_next_char();
 327
 328         value = NULL;
 329         if (c != '\n') {
 330                 if (c != '=')
 331                         return -1;
 332                 value = parse_value();
 333                 if (!value)
 334                         return -1;
 335         }
 336         return fn(name->buf, value, data);
 337 }
 338
 339 static int get_extended_base_var(struct strbuf *name, int c)
 340 {
 341         do {
 342                 if (c == '\n')
 343                         goto error_incomplete_line;
 344                 c = get_next_char();
 345         } while (isspace(c));
 346
 347         /* We require the format to be '[base "extension"]' */
 348         if (c != '"')
 349                 return -1;
 350         strbuf_addch(name, '.');
 351
 352         for (;;) {
 353                 int c = get_next_char();
 354                 if (c == '\n')
 355                         goto error_incomplete_line;
 356                 if (c == '"')
 357                         break;
 358                 if (c == '\\') {
 359                         c = get_next_char();
 360                         if (c == '\n')
 361                                 goto error_incomplete_line;
 362                 }
 363                 strbuf_addch(name, c);
 364         }
 365
 366         /* Final ']' */
 367         if (get_next_char() != ']')
 368                 return -1;
 369         return 0;
 370 error_incomplete_line:
 371         cf->linenr--;
 372         return -1;
 373 }
 374
 375 static int get_base_var(struct strbuf *name)
 376 {
 377         for (;;) {
 378                 int c = get_next_char();
 379                 if (cf->eof)
 380                         return -1;
 381                 if (c == ']')
 382                         return 0;
 383                 if (isspace(c))
 384                         return get_extended_base_var(name, c);
 385                 if (!iskeychar(c) && c != '.')
 386                         return -1;
 387                 strbuf_addch(name, tolower(c));
 388         }
 389 }
 390
 391 static int git_parse_source(config_fn_t fn, void *data)
 392 {
 393         int comment = 0;
 394         int baselen = 0;
 395         struct strbuf *var = &cf->var;
 396
 397         /* U+FEFF Byte Order Mark in UTF8 */
 398         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 399         const unsigned char *bomptr = utf8_bom;
 400
 401         for (;;) {
 402                 int c = get_next_char();
 403                 if (bomptr && *bomptr) {
 404                         /* We are at the file beginning; skip UTF8-encoded BOM
 405                          * if present. Sane editors won't put this in on their
 406                          * own, but e.g. Windows Notepad will do it happily. */
 407                         if ((unsigned char) c == *bomptr) {
 408                                 bomptr++;
 409                                 continue;
 410                         } else {
 411                                 /* Do not tolerate partial BOM. */
 412                                 if (bomptr != utf8_bom)
 413                                         break;
 414                                 /* No BOM at file beginning. Cool. */
 415                                 bomptr = NULL;
 416                         }
 417                 }
 418                 if (c == '\n') {
 419                         if (cf->eof)
 420                                 return 0;
 421                         comment = 0;
 422                         continue;
 423                 }
 424                 if (comment || isspace(c))
 425                         continue;
 426                 if (c == '#' || c == ';') {
 427                         comment = 1;
 428                         continue;
 429                 }
 430                 if (c == '[') {
 431                         /* Reset prior to determining a new stem */
 432                         strbuf_reset(var);
 433                         if (get_base_var(var) < 0 || var->len < 1)
 434                                 break;
 435                         strbuf_addch(var, '.');
 436                         baselen = var->len;
 437                         continue;
 438                 }
 439                 if (!isalpha(c))
 440                         break;
 441                 /*
 442                  * Truncate the var name back to the section header
 443                  * stem prior to grabbing the suffix part of the name
 444                  * and the value.
 445                  */
 446                 strbuf_setlen(var, baselen);
 447                 strbuf_addch(var, tolower(c));
 448                 if (get_value(fn, data, var) < 0)
 449                         break;
 450         }
 451         if (cf->die_on_error)
 452                 die("bad config file line %d in %s", cf->linenr, cf->name);
 453         else
 454                 return error("bad config file line %d in %s", cf->linenr, cf->name);
 455 }
 456
 457 static int parse_unit_factor(const char *end, uintmax_t *val)
 458 {
 459         if (!*end)
 460                 return 1;
 461         else if (!strcasecmp(end, "k")) {
 462                 *val *= 1024;
 463                 return 1;
 464         }
 465         else if (!strcasecmp(end, "m")) {
 466                 *val *= 1024 * 1024;
 467                 return 1;
 468         }
 469         else if (!strcasecmp(end, "g")) {
 470                 *val *= 1024 * 1024 * 1024;
 471                 return 1;
 472         }
 473         return 0;
 474 }
 475
 476 static int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
 477 {
 478         if (value && *value) {
 479                 char *end;
 480                 intmax_t val;
 481                 uintmax_t uval;
 482                 uintmax_t factor = 1;
 483
 484                 errno = 0;
 485                 val = strtoimax(value, &end, 0);
 486                 if (errno == ERANGE)
 487                         return 0;
 488                 if (!parse_unit_factor(end, &factor)) {
 489                         errno = EINVAL;
 490                         return 0;
 491                 }
 492                 uval = abs(val);
 493                 uval *= factor;
 494                 if (uval > max || abs(val) > uval) {
 495                         errno = ERANGE;
 496                         return 0;
 497                 }
 498                 val *= factor;
 499                 *ret = val;
 500                 return 1;
 501         }
 502         errno = EINVAL;
 503         return 0;
 504 }
 505
 506 static int git_parse_unsigned(const char *value, uintmax_t *ret, uintmax_t max)
 507 {
 508         if (value && *value) {
 509                 char *end;
 510                 uintmax_t val;
 511                 uintmax_t oldval;
 512
 513                 errno = 0;
 514                 val = strtoumax(value, &end, 0);
 515                 if (errno == ERANGE)
 516                         return 0;
 517                 oldval = val;
 518                 if (!parse_unit_factor(end, &val)) {
 519                         errno = EINVAL;
 520                         return 0;
 521                 }
 522                 if (val > max || oldval > val) {
 523                         errno = ERANGE;
 524                         return 0;
 525                 }
 526                 *ret = val;
 527                 return 1;
 528         }
 529         errno = EINVAL;
 530         return 0;
 531 }
 532
 533 static int git_parse_int(const char *value, int *ret)
 534 {
 535         intmax_t tmp;
 536         if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int)))
 537                 return 0;
 538         *ret = tmp;
 539         return 1;
 540 }
 541
 542 static int git_parse_int64(const char *value, int64_t *ret)
 543 {
 544         intmax_t tmp;
 545         if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int64_t)))
 546                 return 0;
 547         *ret = tmp;
 548         return 1;
 549 }
 550
 551 int git_parse_ulong(const char *value, unsigned long *ret)
 552 {
 553         uintmax_t tmp;
 554         if (!git_parse_unsigned(value, &tmp, maximum_unsigned_value_of_type(long)))
 555                 return 0;
 556         *ret = tmp;
 557         return 1;
 558 }
 559
 560 NORETURN
 561 static void die_bad_number(const char *name, const char *value)
 562 {
 563         const char *reason = errno == ERANGE ?
 564                              "out of range" :
 565                              "invalid unit";
 566         if (!value)
 567                 value = "";
 568
 569         if (cf && cf->name)
 570                 die("bad numeric config value '%s' for '%s' in %s: %s",
 571                     value, name, cf->name, reason);
 572         die("bad numeric config value '%s' for '%s': %s", value, name, reason);
 573 }
 574
 575 int git_config_int(const char *name, const char *value)
 576 {
 577         int ret;
 578         if (!git_parse_int(value, &ret))
 579                 die_bad_number(name, value);
 580         return ret;
 581 }
 582
 583 int64_t git_config_int64(const char *name, const char *value)
 584 {
 585         int64_t ret;
 586         if (!git_parse_int64(value, &ret))
 587                 die_bad_number(name, value);
 588         return ret;
 589 }
 590
 591 unsigned long git_config_ulong(const char *name, const char *value)
 592 {
 593         unsigned long ret;
 594         if (!git_parse_ulong(value, &ret))
 595                 die_bad_number(name, value);
 596         return ret;
 597 }
 598
 599 static int git_config_maybe_bool_text(const char *name, const char *value)
 600 {
 601         if (!value)
 602                 return 1;
 603         if (!*value)
 604                 return 0;
 605         if (!strcasecmp(value, "true")
 606             || !strcasecmp(value, "yes")
 607             || !strcasecmp(value, "on"))
 608                 return 1;
 609         if (!strcasecmp(value, "false")
 610             || !strcasecmp(value, "no")
 611             || !strcasecmp(value, "off"))
 612                 return 0;
 613         return -1;
 614 }
 615
 616 int git_config_maybe_bool(const char *name, const char *value)
 617 {
 618         int v = git_config_maybe_bool_text(name, value);
 619         if (0 <= v)
 620                 return v;
 621         if (git_parse_int(value, &v))
 622                 return !!v;
 623         return -1;
 624 }
 625
 626 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 627 {
 628         int v = git_config_maybe_bool_text(name, value);
 629         if (0 <= v) {
 630                 *is_bool = 1;
 631                 return v;
 632         }
 633         *is_bool = 0;
 634         return git_config_int(name, value);
 635 }
 636
 637 int git_config_bool(const char *name, const char *value)
 638 {
 639         int discard;
 640         return !!git_config_bool_or_int(name, value, &discard);
 641 }
 642
 643 int git_config_string(const char **dest, const char *var, const char *value)
 644 {
 645         if (!value)
 646                 return config_error_nonbool(var);
 647         *dest = xstrdup(value);
 648         return 0;
 649 }
 650
 651 int git_config_pathname(const char **dest, const char *var, const char *value)
 652 {
 653         if (!value)
 654                 return config_error_nonbool(var);
 655         *dest = expand_user_path(value);
 656         if (!*dest)
 657                 die("Failed to expand user dir in: '%s'", value);
 658         return 0;
 659 }
 660
 661 static int git_default_core_config(const char *var, const char *value)
 662 {
 663         /* This needs a better name */
 664         if (!strcmp(var, "core.filemode")) {
 665                 trust_executable_bit = git_config_bool(var, value);
 666                 return 0;
 667         }
 668         if (!strcmp(var, "core.trustctime")) {
 669                 trust_ctime = git_config_bool(var, value);
 670                 return 0;
 671         }
 672         if (!strcmp(var, "core.checkstat")) {
 673                 if (!strcasecmp(value, "default"))
 674                         check_stat = 1;
 675                 else if (!strcasecmp(value, "minimal"))
 676                         check_stat = 0;
 677         }
 678
 679         if (!strcmp(var, "core.quotepath")) {
 680                 quote_path_fully = git_config_bool(var, value);
 681                 return 0;
 682         }
 683
 684         if (!strcmp(var, "core.symlinks")) {
 685                 has_symlinks = git_config_bool(var, value);
 686                 return 0;
 687         }
 688
 689         if (!strcmp(var, "core.ignorecase")) {
 690                 ignore_case = git_config_bool(var, value);
 691                 return 0;
 692         }
 693
 694         if (!strcmp(var, "core.attributesfile"))
 695                 return git_config_pathname(&git_attributes_file, var, value);
 696
 697         if (!strcmp(var, "core.bare")) {
 698                 is_bare_repository_cfg = git_config_bool(var, value);
 699                 return 0;
 700         }
 701
 702         if (!strcmp(var, "core.ignorestat")) {
 703                 assume_unchanged = git_config_bool(var, value);
 704                 return 0;
 705         }
 706
 707         if (!strcmp(var, "core.prefersymlinkrefs")) {
 708                 prefer_symlink_refs = git_config_bool(var, value);
 709                 return 0;
 710         }
 711
 712         if (!strcmp(var, "core.logallrefupdates")) {
 713                 log_all_ref_updates = git_config_bool(var, value);
 714                 return 0;
 715         }
 716
 717         if (!strcmp(var, "core.warnambiguousrefs")) {
 718                 warn_ambiguous_refs = git_config_bool(var, value);
 719                 return 0;
 720         }
 721
 722         if (!strcmp(var, "core.abbrev")) {
 723                 int abbrev = git_config_int(var, value);
 724                 if (abbrev < minimum_abbrev || abbrev > 40)
 725                         return -1;
 726                 default_abbrev = abbrev;
 727                 return 0;
 728         }
 729
 730         if (!strcmp(var, "core.loosecompression")) {
 731                 int level = git_config_int(var, value);
 732                 if (level == -1)
 733                         level = Z_DEFAULT_COMPRESSION;
 734                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 735                         die("bad zlib compression level %d", level);
 736                 zlib_compression_level = level;
 737                 zlib_compression_seen = 1;
 738                 return 0;
 739         }
 740
 741         if (!strcmp(var, "core.compression")) {
 742                 int level = git_config_int(var, value);
 743                 if (level == -1)
 744                         level = Z_DEFAULT_COMPRESSION;
 745                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 746                         die("bad zlib compression level %d", level);
 747                 core_compression_level = level;
 748                 core_compression_seen = 1;
 749                 if (!zlib_compression_seen)
 750                         zlib_compression_level = level;
 751                 return 0;
 752         }
 753
 754         if (!strcmp(var, "core.packedgitwindowsize")) {
 755                 int pgsz_x2 = getpagesize() * 2;
 756                 packed_git_window_size = git_config_ulong(var, value);
 757
 758                 /* This value must be multiple of (pagesize * 2) */
 759                 packed_git_window_size /= pgsz_x2;
 760                 if (packed_git_window_size < 1)
 761                         packed_git_window_size = 1;
 762                 packed_git_window_size *= pgsz_x2;
 763                 return 0;
 764         }
 765
 766         if (!strcmp(var, "core.bigfilethreshold")) {
 767                 big_file_threshold = git_config_ulong(var, value);
 768                 return 0;
 769         }
 770
 771         if (!strcmp(var, "core.packedgitlimit")) {
 772                 packed_git_limit = git_config_ulong(var, value);
 773                 return 0;
 774         }
 775
 776         if (!strcmp(var, "core.deltabasecachelimit")) {
 777                 delta_base_cache_limit = git_config_ulong(var, value);
 778                 return 0;
 779         }
 780
 781         if (!strcmp(var, "core.autocrlf")) {
 782                 if (value && !strcasecmp(value, "input")) {
 783                         if (core_eol == EOL_CRLF)
 784                                 return error("core.autocrlf=input conflicts with core.eol=crlf");
 785                         auto_crlf = AUTO_CRLF_INPUT;
 786                         return 0;
 787                 }
 788                 auto_crlf = git_config_bool(var, value);
 789                 return 0;
 790         }
 791
 792         if (!strcmp(var, "core.safecrlf")) {
 793                 if (value && !strcasecmp(value, "warn")) {
 794                         safe_crlf = SAFE_CRLF_WARN;
 795                         return 0;
 796                 }
 797                 safe_crlf = git_config_bool(var, value);
 798                 return 0;
 799         }
 800
 801         if (!strcmp(var, "core.eol")) {
 802                 if (value && !strcasecmp(value, "lf"))
 803                         core_eol = EOL_LF;
 804                 else if (value && !strcasecmp(value, "crlf"))
 805                         core_eol = EOL_CRLF;
 806                 else if (value && !strcasecmp(value, "native"))
 807                         core_eol = EOL_NATIVE;
 808                 else
 809                         core_eol = EOL_UNSET;
 810                 if (core_eol == EOL_CRLF && auto_crlf == AUTO_CRLF_INPUT)
 811                         return error("core.autocrlf=input conflicts with core.eol=crlf");
 812                 return 0;
 813         }
 814
 815         if (!strcmp(var, "core.notesref")) {
 816                 notes_ref_name = xstrdup(value);
 817                 return 0;
 818         }
 819
 820         if (!strcmp(var, "core.pager"))
 821                 return git_config_string(&pager_program, var, value);
 822
 823         if (!strcmp(var, "core.editor"))
 824                 return git_config_string(&editor_program, var, value);
 825
 826         if (!strcmp(var, "core.commentchar")) {
 827                 const char *comment;
 828                 int ret = git_config_string(&comment, var, value);
 829                 if (!ret)
 830                         comment_line_char = comment[0];
 831                 return ret;
 832         }
 833
 834         if (!strcmp(var, "core.askpass"))
 835                 return git_config_string(&askpass_program, var, value);
 836
 837         if (!strcmp(var, "core.excludesfile"))
 838                 return git_config_pathname(&excludes_file, var, value);
 839
 840         if (!strcmp(var, "core.whitespace")) {
 841                 if (!value)
 842                         return config_error_nonbool(var);
 843                 whitespace_rule_cfg = parse_whitespace_rule(value);
 844                 return 0;
 845         }
 846
 847         if (!strcmp(var, "core.fsyncobjectfiles")) {
 848                 fsync_object_files = git_config_bool(var, value);
 849                 return 0;
 850         }
 851
 852         if (!strcmp(var, "core.preloadindex")) {
 853                 core_preload_index = git_config_bool(var, value);
 854                 return 0;
 855         }
 856
 857         if (!strcmp(var, "core.createobject")) {
 858                 if (!strcmp(value, "rename"))
 859                         object_creation_mode = OBJECT_CREATION_USES_RENAMES;
 860                 else if (!strcmp(value, "link"))
 861                         object_creation_mode = OBJECT_CREATION_USES_HARDLINKS;
 862                 else
 863                         die("Invalid mode for object creation: %s", value);
 864                 return 0;
 865         }
 866
 867         if (!strcmp(var, "core.sparsecheckout")) {
 868                 core_apply_sparse_checkout = git_config_bool(var, value);
 869                 return 0;
 870         }
 871
 872         if (!strcmp(var, "core.precomposeunicode")) {
 873                 precomposed_unicode = git_config_bool(var, value);
 874                 return 0;
 875         }
 876
 877         if (!strcmp(var, "core.hidedotfiles")) {
 878                 if (value && !strcasecmp(value, "dotgitonly")) {
 879                         hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 880                         return 0;
 881                 }
 882                 hide_dotfiles = git_config_bool(var, value);
 883                 return 0;
 884         }
 885
 886         /* Add other config variables here and to Documentation/config.txt. */
 887         return 0;
 888 }
 889
 890 static int git_default_i18n_config(const char *var, const char *value)
 891 {
 892         if (!strcmp(var, "i18n.commitencoding"))
 893                 return git_config_string(&git_commit_encoding, var, value);
 894
 895         if (!strcmp(var, "i18n.logoutputencoding"))
 896                 return git_config_string(&git_log_output_encoding, var, value);
 897
 898         /* Add other config variables here and to Documentation/config.txt. */
 899         return 0;
 900 }
 901
 902 static int git_default_branch_config(const char *var, const char *value)
 903 {
 904         if (!strcmp(var, "branch.autosetupmerge")) {
 905                 if (value && !strcasecmp(value, "always")) {
 906                         git_branch_track = BRANCH_TRACK_ALWAYS;
 907                         return 0;
 908                 }
 909                 git_branch_track = git_config_bool(var, value);
 910                 return 0;
 911         }
 912         if (!strcmp(var, "branch.autosetuprebase")) {
 913                 if (!value)
 914                         return config_error_nonbool(var);
 915                 else if (!strcmp(value, "never"))
 916                         autorebase = AUTOREBASE_NEVER;
 917                 else if (!strcmp(value, "local"))
 918                         autorebase = AUTOREBASE_LOCAL;
 919                 else if (!strcmp(value, "remote"))
 920                         autorebase = AUTOREBASE_REMOTE;
 921                 else if (!strcmp(value, "always"))
 922                         autorebase = AUTOREBASE_ALWAYS;
 923                 else
 924                         return error("Malformed value for %s", var);
 925                 return 0;
 926         }
 927
 928         /* Add other config variables here and to Documentation/config.txt. */
 929         return 0;
 930 }
 931
 932 static int git_default_push_config(const char *var, const char *value)
 933 {
 934         if (!strcmp(var, "push.default")) {
 935                 if (!value)
 936                         return config_error_nonbool(var);
 937                 else if (!strcmp(value, "nothing"))
 938                         push_default = PUSH_DEFAULT_NOTHING;
 939                 else if (!strcmp(value, "matching"))
 940                         push_default = PUSH_DEFAULT_MATCHING;
 941                 else if (!strcmp(value, "simple"))
 942                         push_default = PUSH_DEFAULT_SIMPLE;
 943                 else if (!strcmp(value, "upstream"))
 944                         push_default = PUSH_DEFAULT_UPSTREAM;
 945                 else if (!strcmp(value, "tracking")) /* deprecated */
 946                         push_default = PUSH_DEFAULT_UPSTREAM;
 947                 else if (!strcmp(value, "current"))
 948                         push_default = PUSH_DEFAULT_CURRENT;
 949                 else {
 950                         error("Malformed value for %s: %s", var, value);
 951                         return error("Must be one of nothing, matching, simple, "
 952                                      "upstream or current.");
 953                 }
 954                 return 0;
 955         }
 956
 957         /* Add other config variables here and to Documentation/config.txt. */
 958         return 0;
 959 }
 960
 961 static int git_default_mailmap_config(const char *var, const char *value)
 962 {
 963         if (!strcmp(var, "mailmap.file"))
 964                 return git_config_string(&git_mailmap_file, var, value);
 965         if (!strcmp(var, "mailmap.blob"))
 966                 return git_config_string(&git_mailmap_blob, var, value);
 967
 968         /* Add other config variables here and to Documentation/config.txt. */
 969         return 0;
 970 }
 971
 972 int git_default_config(const char *var, const char *value, void *dummy)
 973 {
 974         if (starts_with(var, "core."))
 975                 return git_default_core_config(var, value);
 976
 977         if (starts_with(var, "user."))
 978                 return git_ident_config(var, value, dummy);
 979
 980         if (starts_with(var, "i18n."))
 981                 return git_default_i18n_config(var, value);
 982
 983         if (starts_with(var, "branch."))
 984                 return git_default_branch_config(var, value);
 985
 986         if (starts_with(var, "push."))
 987                 return git_default_push_config(var, value);
 988
 989         if (starts_with(var, "mailmap."))
 990                 return git_default_mailmap_config(var, value);
 991
 992         if (starts_with(var, "advice."))
 993                 return git_default_advice_config(var, value);
 994
 995         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 996                 pager_use_color = git_config_bool(var,value);
 997                 return 0;
 998         }
 999
1000         if (!strcmp(var, "pack.packsizelimit")) {
1001                 pack_size_limit_cfg = git_config_ulong(var, value);
1002                 return 0;
1003         }
1004         /* Add other config variables here and to Documentation/config.txt. */
1005         return 0;
1006 }
1007
1008 /*
1009  * All source specific fields in the union, die_on_error, name and the callbacks
1010  * fgetc, ungetc, ftell of top need to be initialized before calling
1011  * this function.
1012  */
1013 static int do_config_from(struct config_source *top, config_fn_t fn, void *data)
1014 {
1015         int ret;
1016
1017         /* push config-file parsing state stack */
1018         top->prev = cf;
1019         top->linenr = 1;
1020         top->eof = 0;
1021         strbuf_init(&top->value, 1024);
1022         strbuf_init(&top->var, 1024);
1023         cf = top;
1024
1025         ret = git_parse_source(fn, data);
1026
1027         /* pop config-file parsing state stack */
1028         strbuf_release(&top->value);
1029         strbuf_release(&top->var);
1030         cf = top->prev;
1031
1032         return ret;
1033 }
1034
1035 static int do_config_from_file(config_fn_t fn,
1036                 const char *name, const char *path, FILE *f, void *data)
1037 {
1038         struct config_source top;
1039
1040         top.u.file = f;
1041         top.name = name;
1042         top.path = path;
1043         top.die_on_error = 1;
1044         top.do_fgetc = config_file_fgetc;
1045         top.do_ungetc = config_file_ungetc;
1046         top.do_ftell = config_file_ftell;
1047
1048         return do_config_from(&top, fn, data);
1049 }
1050
1051 static int git_config_from_stdin(config_fn_t fn, void *data)
1052 {
1053         return do_config_from_file(fn, "<stdin>", NULL, stdin, data);
1054 }
1055
1056 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
1057 {
1058         int ret = -1;
1059         FILE *f;
1060
1061         f = fopen(filename, "r");
1062         if (f) {
1063                 ret = do_config_from_file(fn, filename, filename, f, data);
1064                 fclose(f);
1065         }
1066         return ret;
1067 }
1068
1069 int git_config_from_buf(config_fn_t fn, const char *name, const char *buf,
1070                         size_t len, void *data)
1071 {
1072         struct config_source top;
1073
1074         top.u.buf.buf = buf;
1075         top.u.buf.len = len;
1076         top.u.buf.pos = 0;
1077         top.name = name;
1078         top.path = NULL;
1079         top.die_on_error = 0;
1080         top.do_fgetc = config_buf_fgetc;
1081         top.do_ungetc = config_buf_ungetc;
1082         top.do_ftell = config_buf_ftell;
1083
1084         return do_config_from(&top, fn, data);
1085 }
1086
1087 static int git_config_from_blob_sha1(config_fn_t fn,
1088                                      const char *name,
1089                                      const unsigned char *sha1,
1090                                      void *data)
1091 {
1092         enum object_type type;
1093         char *buf;
1094         unsigned long size;
1095         int ret;
1096
1097         buf = read_sha1_file(sha1, &type, &size);
1098         if (!buf)
1099                 return error("unable to load config blob object '%s'", name);
1100         if (type != OBJ_BLOB) {
1101                 free(buf);
1102                 return error("reference '%s' does not point to a blob", name);
1103         }
1104
1105         ret = git_config_from_buf(fn, name, buf, size, data);
1106         free(buf);
1107
1108         return ret;
1109 }
1110
1111 static int git_config_from_blob_ref(config_fn_t fn,
1112                                     const char *name,
1113                                     void *data)
1114 {
1115         unsigned char sha1[20];
1116
1117         if (get_sha1(name, sha1) < 0)
1118                 return error("unable to resolve config blob '%s'", name);
1119         return git_config_from_blob_sha1(fn, name, sha1, data);
1120 }
1121
1122 const char *git_etc_gitconfig(void)
1123 {
1124         static const char *system_wide;
1125         if (!system_wide)
1126                 system_wide = system_path(ETC_GITCONFIG);
1127         return system_wide;
1128 }
1129
1130 int git_env_bool(const char *k, int def)
1131 {
1132         const char *v = getenv(k);
1133         return v ? git_config_bool(k, v) : def;
1134 }
1135
1136 int git_config_system(void)
1137 {
1138         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
1139 }
1140
1141 int git_config_early(config_fn_t fn, void *data, const char *repo_config)
1142 {
1143         int ret = 0, found = 0;
1144         char *xdg_config = NULL;
1145         char *user_config = NULL;
1146
1147         home_config_paths(&user_config, &xdg_config, "config");
1148
1149         if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK, 0)) {
1150                 ret += git_config_from_file(fn, git_etc_gitconfig(),
1151                                             data);
1152                 found += 1;
1153         }
1154
1155         if (xdg_config && !access_or_die(xdg_config, R_OK, ACCESS_EACCES_OK)) {
1156                 ret += git_config_from_file(fn, xdg_config, data);
1157                 found += 1;
1158         }
1159
1160         if (user_config && !access_or_die(user_config, R_OK, ACCESS_EACCES_OK)) {
1161                 ret += git_config_from_file(fn, user_config, data);
1162                 found += 1;
1163         }
1164
1165         if (repo_config && !access_or_die(repo_config, R_OK, 0)) {
1166                 ret += git_config_from_file(fn, repo_config, data);
1167                 found += 1;
1168         }
1169
1170         switch (git_config_from_parameters(fn, data)) {
1171         case -1: /* error */
1172                 die("unable to parse command-line config");
1173                 break;
1174         case 0: /* found nothing */
1175                 break;
1176         default: /* found at least one item */
1177                 found++;
1178                 break;
1179         }
1180
1181         free(xdg_config);
1182         free(user_config);
1183         return ret == 0 ? found : ret;
1184 }
1185
1186 int git_config_with_options(config_fn_t fn, void *data,
1187                             struct git_config_source *config_source,
1188                             int respect_includes)
1189 {
1190         char *repo_config = NULL;
1191         int ret;
1192         struct config_include_data inc = CONFIG_INCLUDE_INIT;
1193
1194         if (respect_includes) {
1195                 inc.fn = fn;
1196                 inc.data = data;
1197                 fn = git_config_include;
1198                 data = &inc;
1199         }
1200
1201         /*
1202          * If we have a specific filename, use it. Otherwise, follow the
1203          * regular lookup sequence.
1204          */
1205         if (config_source && config_source->use_stdin)
1206                 return git_config_from_stdin(fn, data);
1207         else if (config_source && config_source->file)
1208                 return git_config_from_file(fn, config_source->file, data);
1209         else if (config_source && config_source->blob)
1210                 return git_config_from_blob_ref(fn, config_source->blob, data);
1211
1212         repo_config = git_pathdup("config");
1213         ret = git_config_early(fn, data, repo_config);
1214         if (repo_config)
1215                 free(repo_config);
1216         return ret;
1217 }
1218
1219 int git_config(config_fn_t fn, void *data)
1220 {
1221         return git_config_with_options(fn, data, NULL, 1);
1222 }
1223
1224 /*
1225  * Find all the stuff for git_config_set() below.
1226  */
1227
1228 static struct {
1229         int baselen;
1230         char *key;
1231         int do_not_match;
1232         regex_t *value_regex;
1233         int multi_replace;
1234         size_t *offset;
1235         unsigned int offset_alloc;
1236         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
1237         int seen;
1238 } store;
1239
1240 static int matches(const char *key, const char *value)
1241 {
1242         return !strcmp(key, store.key) &&
1243                 (store.value_regex == NULL ||
1244                  (store.do_not_match ^
1245                   !regexec(store.value_regex, value, 0, NULL, 0)));
1246 }
1247
1248 static int store_aux(const char *key, const char *value, void *cb)
1249 {
1250         const char *ep;
1251         size_t section_len;
1252
1253         switch (store.state) {
1254         case KEY_SEEN:
1255                 if (matches(key, value)) {
1256                         if (store.seen == 1 && store.multi_replace == 0) {
1257                                 warning("%s has multiple values", key);
1258                         }
1259
1260                         ALLOC_GROW(store.offset, store.seen + 1,
1261                                    store.offset_alloc);
1262
1263                         store.offset[store.seen] = cf->do_ftell(cf);
1264                         store.seen++;
1265                 }
1266                 break;
1267         case SECTION_SEEN:
1268                 /*
1269                  * What we are looking for is in store.key (both
1270                  * section and var), and its section part is baselen
1271                  * long.  We found key (again, both section and var).
1272                  * We would want to know if this key is in the same
1273                  * section as what we are looking for.  We already
1274                  * know we are in the same section as what should
1275                  * hold store.key.
1276                  */
1277                 ep = strrchr(key, '.');
1278                 section_len = ep - key;
1279
1280                 if ((section_len != store.baselen) ||
1281                     memcmp(key, store.key, section_len+1)) {
1282                         store.state = SECTION_END_SEEN;
1283                         break;
1284                 }
1285
1286                 /*
1287                  * Do not increment matches: this is no match, but we
1288                  * just made sure we are in the desired section.
1289                  */
1290                 ALLOC_GROW(store.offset, store.seen + 1,
1291                            store.offset_alloc);
1292                 store.offset[store.seen] = cf->do_ftell(cf);
1293                 /* fallthru */
1294         case SECTION_END_SEEN:
1295         case START:
1296                 if (matches(key, value)) {
1297                         ALLOC_GROW(store.offset, store.seen + 1,
1298                                    store.offset_alloc);
1299                         store.offset[store.seen] = cf->do_ftell(cf);
1300                         store.state = KEY_SEEN;
1301                         store.seen++;
1302                 } else {
1303                         if (strrchr(key, '.') - key == store.baselen &&
1304                               !strncmp(key, store.key, store.baselen)) {
1305                                         store.state = SECTION_SEEN;
1306                                         ALLOC_GROW(store.offset,
1307                                                    store.seen + 1,
1308                                                    store.offset_alloc);
1309                                         store.offset[store.seen] = cf->do_ftell(cf);
1310                         }
1311                 }
1312         }
1313         return 0;
1314 }
1315
1316 static int write_error(const char *filename)
1317 {
1318         error("failed to write new configuration file %s", filename);
1319
1320         /* Same error code as "failed to rename". */
1321         return 4;
1322 }
1323
1324 static int store_write_section(int fd, const char *key)
1325 {
1326         const char *dot;
1327         int i, success;
1328         struct strbuf sb = STRBUF_INIT;
1329
1330         dot = memchr(key, '.', store.baselen);
1331         if (dot) {
1332                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
1333                 for (i = dot - key + 1; i < store.baselen; i++) {
1334                         if (key[i] == '"' || key[i] == '\\')
1335                                 strbuf_addch(&sb, '\\');
1336                         strbuf_addch(&sb, key[i]);
1337                 }
1338                 strbuf_addstr(&sb, "\"]\n");
1339         } else {
1340                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
1341         }
1342
1343         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
1344         strbuf_release(&sb);
1345
1346         return success;
1347 }
1348
1349 static int store_write_pair(int fd, const char *key, const char *value)
1350 {
1351         int i, success;
1352         int length = strlen(key + store.baselen + 1);
1353         const char *quote = "";
1354         struct strbuf sb = STRBUF_INIT;
1355
1356         /*
1357          * Check to see if the value needs to be surrounded with a dq pair.
1358          * Note that problematic characters are always backslash-quoted; this
1359          * check is about not losing leading or trailing SP and strings that
1360          * follow beginning-of-comment characters (i.e. ';' and '#') by the
1361          * configuration parser.
1362          */
1363         if (value[0] == ' ')
1364                 quote = "\"";
1365         for (i = 0; value[i]; i++)
1366                 if (value[i] == ';' || value[i] == '#')
1367                         quote = "\"";
1368         if (i && value[i - 1] == ' ')
1369                 quote = "\"";
1370
1371         strbuf_addf(&sb, "\t%.*s = %s",
1372                     length, key + store.baselen + 1, quote);
1373
1374         for (i = 0; value[i]; i++)
1375                 switch (value[i]) {
1376                 case '\n':
1377                         strbuf_addstr(&sb, "\\n");
1378                         break;
1379                 case '\t':
1380                         strbuf_addstr(&sb, "\\t");
1381                         break;
1382                 case '"':
1383                 case '\\':
1384                         strbuf_addch(&sb, '\\');
1385                 default:
1386                         strbuf_addch(&sb, value[i]);
1387                         break;
1388                 }
1389         strbuf_addf(&sb, "%s\n", quote);
1390
1391         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
1392         strbuf_release(&sb);
1393
1394         return success;
1395 }
1396
1397 static ssize_t find_beginning_of_line(const char *contents, size_t size,
1398         size_t offset_, int *found_bracket)
1399 {
1400         size_t equal_offset = size, bracket_offset = size;
1401         ssize_t offset;
1402
1403 contline:
1404         for (offset = offset_-2; offset > 0
1405                         && contents[offset] != '\n'; offset--)
1406                 switch (contents[offset]) {
1407                         case '=': equal_offset = offset; break;
1408                         case ']': bracket_offset = offset; break;
1409                 }
1410         if (offset > 0 && contents[offset-1] == '\\') {
1411                 offset_ = offset;
1412                 goto contline;
1413         }
1414         if (bracket_offset < equal_offset) {
1415                 *found_bracket = 1;
1416                 offset = bracket_offset+1;
1417         } else
1418                 offset++;
1419
1420         return offset;
1421 }
1422
1423 int git_config_set_in_file(const char *config_filename,
1424                         const char *key, const char *value)
1425 {
1426         return git_config_set_multivar_in_file(config_filename, key, value, NULL, 0);
1427 }
1428
1429 int git_config_set(const char *key, const char *value)
1430 {
1431         return git_config_set_multivar(key, value, NULL, 0);
1432 }
1433
1434 /*
1435  * Auxiliary function to sanity-check and split the key into the section
1436  * identifier and variable name.
1437  *
1438  * Returns 0 on success, -1 when there is an invalid character in the key and
1439  * -2 if there is no section name in the key.
1440  *
1441  * store_key - pointer to char* which will hold a copy of the key with
1442  *             lowercase section and variable name
1443  * baselen - pointer to int which will hold the length of the
1444  *           section + subsection part, can be NULL
1445  */
1446 int git_config_parse_key(const char *key, char **store_key, int *baselen_)
1447 {
1448         int i, dot, baselen;
1449         const char *last_dot = strrchr(key, '.');
1450
1451         /*
1452          * Since "key" actually contains the section name and the real
1453          * key name separated by a dot, we have to know where the dot is.
1454          */
1455
1456         if (last_dot == NULL || last_dot == key) {
1457                 error("key does not contain a section: %s", key);
1458                 return -CONFIG_NO_SECTION_OR_NAME;
1459         }
1460
1461         if (!last_dot[1]) {
1462                 error("key does not contain variable name: %s", key);
1463                 return -CONFIG_NO_SECTION_OR_NAME;
1464         }
1465
1466         baselen = last_dot - key;
1467         if (baselen_)
1468                 *baselen_ = baselen;
1469
1470         /*
1471          * Validate the key and while at it, lower case it for matching.
1472          */
1473         *store_key = xmalloc(strlen(key) + 1);
1474
1475         dot = 0;
1476         for (i = 0; key[i]; i++) {
1477                 unsigned char c = key[i];
1478                 if (c == '.')
1479                         dot = 1;
1480                 /* Leave the extended basename untouched.. */
1481                 if (!dot || i > baselen) {
1482                         if (!iskeychar(c) ||
1483                             (i == baselen + 1 && !isalpha(c))) {
1484                                 error("invalid key: %s", key);
1485                                 goto out_free_ret_1;
1486                         }
1487                         c = tolower(c);
1488                 } else if (c == '\n') {
1489                         error("invalid key (newline): %s", key);
1490                         goto out_free_ret_1;
1491                 }
1492                 (*store_key)[i] = c;
1493         }
1494         (*store_key)[i] = 0;
1495
1496         return 0;
1497
1498 out_free_ret_1:
1499         free(*store_key);
1500         *store_key = NULL;
1501         return -CONFIG_INVALID_KEY;
1502 }
1503
1504 /*
1505  * If value==NULL, unset in (remove from) config,
1506  * if value_regex!=NULL, disregard key/value pairs where value does not match.
1507  * if multi_replace==0, nothing, or only one matching key/value is replaced,
1508  *     else all matching key/values (regardless how many) are removed,
1509  *     before the new pair is written.
1510  *
1511  * Returns 0 on success.
1512  *
1513  * This function does this:
1514  *
1515  * - it locks the config file by creating ".git/config.lock"
1516  *
1517  * - it then parses the config using store_aux() as validator to find
1518  *   the position on the key/value pair to replace. If it is to be unset,
1519  *   it must be found exactly once.
1520  *
1521  * - the config file is mmap()ed and the part before the match (if any) is
1522  *   written to the lock file, then the changed part and the rest.
1523  *
1524  * - the config file is removed and the lock file rename()d to it.
1525  *
1526  */
1527 int git_config_set_multivar_in_file(const char *config_filename,
1528                                 const char *key, const char *value,
1529                                 const char *value_regex, int multi_replace)
1530 {
1531         int fd = -1, in_fd;
1532         int ret;
1533         struct lock_file *lock = NULL;
1534         char *filename_buf = NULL;
1535
1536         /* parse-key returns negative; flip the sign to feed exit(3) */
1537         ret = 0 - git_config_parse_key(key, &store.key, &store.baselen);
1538         if (ret)
1539                 goto out_free;
1540
1541         store.multi_replace = multi_replace;
1542
1543         if (!config_filename)
1544                 config_filename = filename_buf = git_pathdup("config");
1545
1546         /*
1547          * The lock serves a purpose in addition to locking: the new
1548          * contents of .git/config will be written into it.
1549          */
1550         lock = xcalloc(sizeof(struct lock_file), 1);
1551         fd = hold_lock_file_for_update(lock, config_filename, 0);
1552         if (fd < 0) {
1553                 error("could not lock config file %s: %s", config_filename, strerror(errno));
1554                 free(store.key);
1555                 ret = CONFIG_NO_LOCK;
1556                 goto out_free;
1557         }
1558
1559         /*
1560          * If .git/config does not exist yet, write a minimal version.
1561          */
1562         in_fd = open(config_filename, O_RDONLY);
1563         if ( in_fd < 0 ) {
1564                 free(store.key);
1565
1566                 if ( ENOENT != errno ) {
1567                         error("opening %s: %s", config_filename,
1568                               strerror(errno));
1569                         ret = CONFIG_INVALID_FILE; /* same as "invalid config file" */
1570                         goto out_free;
1571                 }
1572                 /* if nothing to unset, error out */
1573                 if (value == NULL) {
1574                         ret = CONFIG_NOTHING_SET;
1575                         goto out_free;
1576                 }
1577
1578                 store.key = (char *)key;
1579                 if (!store_write_section(fd, key) ||
1580                     !store_write_pair(fd, key, value))
1581                         goto write_err_out;
1582         } else {
1583                 struct stat st;
1584                 char *contents;
1585                 size_t contents_sz, copy_begin, copy_end;
1586                 int i, new_line = 0;
1587
1588                 if (value_regex == NULL)
1589                         store.value_regex = NULL;
1590                 else {
1591                         if (value_regex[0] == '!') {
1592                                 store.do_not_match = 1;
1593                                 value_regex++;
1594                         } else
1595                                 store.do_not_match = 0;
1596
1597                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
1598                         if (regcomp(store.value_regex, value_regex,
1599                                         REG_EXTENDED)) {
1600                                 error("invalid pattern: %s", value_regex);
1601                                 free(store.value_regex);
1602                                 ret = CONFIG_INVALID_PATTERN;
1603                                 goto out_free;
1604                         }
1605                 }
1606
1607                 ALLOC_GROW(store.offset, 1, store.offset_alloc);
1608                 store.offset[0] = 0;
1609                 store.state = START;
1610                 store.seen = 0;
1611
1612                 /*
1613                  * After this, store.offset will contain the *end* offset
1614                  * of the last match, or remain at 0 if no match was found.
1615                  * As a side effect, we make sure to transform only a valid
1616                  * existing config file.
1617                  */
1618                 if (git_config_from_file(store_aux, config_filename, NULL)) {
1619                         error("invalid config file %s", config_filename);
1620                         free(store.key);
1621                         if (store.value_regex != NULL) {
1622                                 regfree(store.value_regex);
1623                                 free(store.value_regex);
1624                         }
1625                         ret = CONFIG_INVALID_FILE;
1626                         goto out_free;
1627                 }
1628
1629                 free(store.key);
1630                 if (store.value_regex != NULL) {
1631                         regfree(store.value_regex);
1632                         free(store.value_regex);
1633                 }
1634
1635                 /* if nothing to unset, or too many matches, error out */
1636                 if ((store.seen == 0 && value == NULL) ||
1637                                 (store.seen > 1 && multi_replace == 0)) {
1638                         ret = CONFIG_NOTHING_SET;
1639                         goto out_free;
1640                 }
1641
1642                 fstat(in_fd, &st);
1643                 contents_sz = xsize_t(st.st_size);
1644                 contents = xmmap(NULL, contents_sz, PROT_READ,
1645                         MAP_PRIVATE, in_fd, 0);
1646                 close(in_fd);
1647
1648                 if (store.seen == 0)
1649                         store.seen = 1;
1650
1651                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1652                         if (store.offset[i] == 0) {
1653                                 store.offset[i] = copy_end = contents_sz;
1654                         } else if (store.state != KEY_SEEN) {
1655                                 copy_end = store.offset[i];
1656                         } else
1657                                 copy_end = find_beginning_of_line(
1658                                         contents, contents_sz,
1659                                         store.offset[i]-2, &new_line);
1660
1661                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1662                                 new_line = 1;
1663
1664                         /* write the first part of the config */
1665                         if (copy_end > copy_begin) {
1666                                 if (write_in_full(fd, contents + copy_begin,
1667                                                   copy_end - copy_begin) <
1668                                     copy_end - copy_begin)
1669                                         goto write_err_out;
1670                                 if (new_line &&
1671                                     write_str_in_full(fd, "\n") != 1)
1672                                         goto write_err_out;
1673                         }
1674                         copy_begin = store.offset[i];
1675                 }
1676
1677                 /* write the pair (value == NULL means unset) */
1678                 if (value != NULL) {
1679                         if (store.state == START) {
1680                                 if (!store_write_section(fd, key))
1681                                         goto write_err_out;
1682                         }
1683                         if (!store_write_pair(fd, key, value))
1684                                 goto write_err_out;
1685                 }
1686
1687                 /* write the rest of the config */
1688                 if (copy_begin < contents_sz)
1689                         if (write_in_full(fd, contents + copy_begin,
1690                                           contents_sz - copy_begin) <
1691                             contents_sz - copy_begin)
1692                                 goto write_err_out;
1693
1694                 munmap(contents, contents_sz);
1695         }
1696
1697         if (commit_lock_file(lock) < 0) {
1698                 error("could not commit config file %s", config_filename);
1699                 ret = CONFIG_NO_WRITE;
1700                 goto out_free;
1701         }
1702
1703         /*
1704          * lock is committed, so don't try to roll it back below.
1705          * NOTE: Since lockfile.c keeps a linked list of all created
1706          * lock_file structures, it isn't safe to free(lock).  It's
1707          * better to just leave it hanging around.
1708          */
1709         lock = NULL;
1710         ret = 0;
1711
1712 out_free:
1713         if (lock)
1714                 rollback_lock_file(lock);
1715         free(filename_buf);
1716         return ret;
1717
1718 write_err_out:
1719         ret = write_error(lock->filename);
1720         goto out_free;
1721
1722 }
1723
1724 int git_config_set_multivar(const char *key, const char *value,
1725                         const char *value_regex, int multi_replace)
1726 {
1727         return git_config_set_multivar_in_file(NULL, key, value, value_regex,
1728                                                multi_replace);
1729 }
1730
1731 static int section_name_match (const char *buf, const char *name)
1732 {
1733         int i = 0, j = 0, dot = 0;
1734         if (buf[i] != '[')
1735                 return 0;
1736         for (i = 1; buf[i] && buf[i] != ']'; i++) {
1737                 if (!dot && isspace(buf[i])) {
1738                         dot = 1;
1739                         if (name[j++] != '.')
1740                                 break;
1741                         for (i++; isspace(buf[i]); i++)
1742                                 ; /* do nothing */
1743                         if (buf[i] != '"')
1744                                 break;
1745                         continue;
1746                 }
1747                 if (buf[i] == '\\' && dot)
1748                         i++;
1749                 else if (buf[i] == '"' && dot) {
1750                         for (i++; isspace(buf[i]); i++)
1751                                 ; /* do_nothing */
1752                         break;
1753                 }
1754                 if (buf[i] != name[j++])
1755                         break;
1756         }
1757         if (buf[i] == ']' && name[j] == 0) {
1758                 /*
1759                  * We match, now just find the right length offset by
1760                  * gobbling up any whitespace after it, as well
1761                  */
1762                 i++;
1763                 for (; buf[i] && isspace(buf[i]); i++)
1764                         ; /* do nothing */
1765                 return i;
1766         }
1767         return 0;
1768 }
1769
1770 static int section_name_is_ok(const char *name)
1771 {
1772         /* Empty section names are bogus. */
1773         if (!*name)
1774                 return 0;
1775
1776         /*
1777          * Before a dot, we must be alphanumeric or dash. After the first dot,
1778          * anything goes, so we can stop checking.
1779          */
1780         for (; *name && *name != '.'; name++)
1781                 if (*name != '-' && !isalnum(*name))
1782                         return 0;
1783         return 1;
1784 }
1785
1786 /* if new_name == NULL, the section is removed instead */
1787 int git_config_rename_section_in_file(const char *config_filename,
1788                                       const char *old_name, const char *new_name)
1789 {
1790         int ret = 0, remove = 0;
1791         char *filename_buf = NULL;
1792         struct lock_file *lock;
1793         int out_fd;
1794         char buf[1024];
1795         FILE *config_file;
1796
1797         if (new_name && !section_name_is_ok(new_name)) {
1798                 ret = error("invalid section name: %s", new_name);
1799                 goto out;
1800         }
1801
1802         if (!config_filename)
1803                 config_filename = filename_buf = git_pathdup("config");
1804
1805         lock = xcalloc(sizeof(struct lock_file), 1);
1806         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1807         if (out_fd < 0) {
1808                 ret = error("could not lock config file %s", config_filename);
1809                 goto out;
1810         }
1811
1812         if (!(config_file = fopen(config_filename, "rb"))) {
1813                 /* no config file means nothing to rename, no error */
1814                 goto unlock_and_out;
1815         }
1816
1817         while (fgets(buf, sizeof(buf), config_file)) {
1818                 int i;
1819                 int length;
1820                 char *output = buf;
1821                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1822                         ; /* do nothing */
1823                 if (buf[i] == '[') {
1824                         /* it's a section */
1825                         int offset = section_name_match(&buf[i], old_name);
1826                         if (offset > 0) {
1827                                 ret++;
1828                                 if (new_name == NULL) {
1829                                         remove = 1;
1830                                         continue;
1831                                 }
1832                                 store.baselen = strlen(new_name);
1833                                 if (!store_write_section(out_fd, new_name)) {
1834                                         ret = write_error(lock->filename);
1835                                         goto out;
1836                                 }
1837                                 /*
1838                                  * We wrote out the new section, with
1839                                  * a newline, now skip the old
1840                                  * section's length
1841                                  */
1842                                 output += offset + i;
1843                                 if (strlen(output) > 0) {
1844                                         /*
1845                                          * More content means there's
1846                                          * a declaration to put on the
1847                                          * next line; indent with a
1848                                          * tab
1849                                          */
1850                                         output -= 1;
1851                                         output[0] = '\t';
1852                                 }
1853                         }
1854                         remove = 0;
1855                 }
1856                 if (remove)
1857                         continue;
1858                 length = strlen(output);
1859                 if (write_in_full(out_fd, output, length) != length) {
1860                         ret = write_error(lock->filename);
1861                         goto out;
1862                 }
1863         }
1864         fclose(config_file);
1865 unlock_and_out:
1866         if (commit_lock_file(lock) < 0)
1867                 ret = error("could not commit config file %s", config_filename);
1868 out:
1869         free(filename_buf);
1870         return ret;
1871 }
1872
1873 int git_config_rename_section(const char *old_name, const char *new_name)
1874 {
1875         return git_config_rename_section_in_file(NULL, old_name, new_name);
1876 }
1877
1878 /*
1879  * Call this to report error for your variable that should not
1880  * get a boolean value (i.e. "[my] var" means "true").
1881  */
1882 #undef config_error_nonbool
1883 int config_error_nonbool(const char *var)
1884 {
1885         return error("Missing value for '%s'", var);
1886 }
1887
1888 int parse_config_key(const char *var,
1889                      const char *section,
1890                      const char **subsection, int *subsection_len,
1891                      const char **key)
1892 {
1893         int section_len = strlen(section);
1894         const char *dot;
1895
1896         /* Does it start with "section." ? */
1897         if (!starts_with(var, section) || var[section_len] != '.')
1898                 return -1;
1899
1900         /*
1901          * Find the key; we don't know yet if we have a subsection, but we must
1902          * parse backwards from the end, since the subsection may have dots in
1903          * it, too.
1904          */
1905         dot = strrchr(var, '.');
1906         *key = dot + 1;
1907
1908         /* Did we have a subsection at all? */
1909         if (dot == var + section_len) {
1910                 *subsection = NULL;
1911                 *subsection_len = 0;
1912         }
1913         else {
1914                 *subsection = var + section_len + 1;
1915                 *subsection_len = dot - *subsection;
1916         }
1917
1918         return 0;
1919 }