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.protecthfs")) {
 878                 protect_hfs = git_config_bool(var, value);
 879                 return 0;
 880         }
 881
 882         if (!strcmp(var, "core.protectntfs")) {
 883                 protect_ntfs = git_config_bool(var, value);
 884                 return 0;
 885         }
 886
 887         /* Add other config variables here and to Documentation/config.txt. */
 888         return 0;
 889 }
 890
 891 static int git_default_i18n_config(const char *var, const char *value)
 892 {
 893         if (!strcmp(var, "i18n.commitencoding"))
 894                 return git_config_string(&git_commit_encoding, var, value);
 895
 896         if (!strcmp(var, "i18n.logoutputencoding"))
 897                 return git_config_string(&git_log_output_encoding, var, value);
 898
 899         /* Add other config variables here and to Documentation/config.txt. */
 900         return 0;
 901 }
 902
 903 static int git_default_branch_config(const char *var, const char *value)
 904 {
 905         if (!strcmp(var, "branch.autosetupmerge")) {
 906                 if (value && !strcasecmp(value, "always")) {
 907                         git_branch_track = BRANCH_TRACK_ALWAYS;
 908                         return 0;
 909                 }
 910                 git_branch_track = git_config_bool(var, value);
 911                 return 0;
 912         }
 913         if (!strcmp(var, "branch.autosetuprebase")) {
 914                 if (!value)
 915                         return config_error_nonbool(var);
 916                 else if (!strcmp(value, "never"))
 917                         autorebase = AUTOREBASE_NEVER;
 918                 else if (!strcmp(value, "local"))
 919                         autorebase = AUTOREBASE_LOCAL;
 920                 else if (!strcmp(value, "remote"))
 921                         autorebase = AUTOREBASE_REMOTE;
 922                 else if (!strcmp(value, "always"))
 923                         autorebase = AUTOREBASE_ALWAYS;
 924                 else
 925                         return error("Malformed value for %s", var);
 926                 return 0;
 927         }
 928
 929         /* Add other config variables here and to Documentation/config.txt. */
 930         return 0;
 931 }
 932
 933 static int git_default_push_config(const char *var, const char *value)
 934 {
 935         if (!strcmp(var, "push.default")) {
 936                 if (!value)
 937                         return config_error_nonbool(var);
 938                 else if (!strcmp(value, "nothing"))
 939                         push_default = PUSH_DEFAULT_NOTHING;
 940                 else if (!strcmp(value, "matching"))
 941                         push_default = PUSH_DEFAULT_MATCHING;
 942                 else if (!strcmp(value, "simple"))
 943                         push_default = PUSH_DEFAULT_SIMPLE;
 944                 else if (!strcmp(value, "upstream"))
 945                         push_default = PUSH_DEFAULT_UPSTREAM;
 946                 else if (!strcmp(value, "tracking")) /* deprecated */
 947                         push_default = PUSH_DEFAULT_UPSTREAM;
 948                 else if (!strcmp(value, "current"))
 949                         push_default = PUSH_DEFAULT_CURRENT;
 950                 else {
 951                         error("Malformed value for %s: %s", var, value);
 952                         return error("Must be one of nothing, matching, simple, "
 953                                      "upstream or current.");
 954                 }
 955                 return 0;
 956         }
 957
 958         /* Add other config variables here and to Documentation/config.txt. */
 959         return 0;
 960 }
 961
 962 static int git_default_mailmap_config(const char *var, const char *value)
 963 {
 964         if (!strcmp(var, "mailmap.file"))
 965                 return git_config_pathname(&git_mailmap_file, var, value);
 966         if (!strcmp(var, "mailmap.blob"))
 967                 return git_config_string(&git_mailmap_blob, var, value);
 968
 969         /* Add other config variables here and to Documentation/config.txt. */
 970         return 0;
 971 }
 972
 973 int git_default_config(const char *var, const char *value, void *dummy)
 974 {
 975         if (starts_with(var, "core."))
 976                 return git_default_core_config(var, value);
 977
 978         if (starts_with(var, "user."))
 979                 return git_ident_config(var, value, dummy);
 980
 981         if (starts_with(var, "i18n."))
 982                 return git_default_i18n_config(var, value);
 983
 984         if (starts_with(var, "branch."))
 985                 return git_default_branch_config(var, value);
 986
 987         if (starts_with(var, "push."))
 988                 return git_default_push_config(var, value);
 989
 990         if (starts_with(var, "mailmap."))
 991                 return git_default_mailmap_config(var, value);
 992
 993         if (starts_with(var, "advice."))
 994                 return git_default_advice_config(var, value);
 995
 996         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 997                 pager_use_color = git_config_bool(var,value);
 998                 return 0;
 999         }
1000
1001         if (!strcmp(var, "pack.packsizelimit")) {
1002                 pack_size_limit_cfg = git_config_ulong(var, value);
1003                 return 0;
1004         }
1005         /* Add other config variables here and to Documentation/config.txt. */
1006         return 0;
1007 }
1008
1009 /*
1010  * All source specific fields in the union, die_on_error, name and the callbacks
1011  * fgetc, ungetc, ftell of top need to be initialized before calling
1012  * this function.
1013  */
1014 static int do_config_from(struct config_source *top, config_fn_t fn, void *data)
1015 {
1016         int ret;
1017
1018         /* push config-file parsing state stack */
1019         top->prev = cf;
1020         top->linenr = 1;
1021         top->eof = 0;
1022         strbuf_init(&top->value, 1024);
1023         strbuf_init(&top->var, 1024);
1024         cf = top;
1025
1026         ret = git_parse_source(fn, data);
1027
1028         /* pop config-file parsing state stack */
1029         strbuf_release(&top->value);
1030         strbuf_release(&top->var);
1031         cf = top->prev;
1032
1033         return ret;
1034 }
1035
1036 static int do_config_from_file(config_fn_t fn,
1037                 const char *name, const char *path, FILE *f, void *data)
1038 {
1039         struct config_source top;
1040
1041         top.u.file = f;
1042         top.name = name;
1043         top.path = path;
1044         top.die_on_error = 1;
1045         top.do_fgetc = config_file_fgetc;
1046         top.do_ungetc = config_file_ungetc;
1047         top.do_ftell = config_file_ftell;
1048
1049         return do_config_from(&top, fn, data);
1050 }
1051
1052 static int git_config_from_stdin(config_fn_t fn, void *data)
1053 {
1054         return do_config_from_file(fn, "<stdin>", NULL, stdin, data);
1055 }
1056
1057 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
1058 {
1059         int ret = -1;
1060         FILE *f;
1061
1062         f = fopen(filename, "r");
1063         if (f) {
1064                 ret = do_config_from_file(fn, filename, filename, f, data);
1065                 fclose(f);
1066         }
1067         return ret;
1068 }
1069
1070 int git_config_from_buf(config_fn_t fn, const char *name, const char *buf,
1071                         size_t len, void *data)
1072 {
1073         struct config_source top;
1074
1075         top.u.buf.buf = buf;
1076         top.u.buf.len = len;
1077         top.u.buf.pos = 0;
1078         top.name = name;
1079         top.path = NULL;
1080         top.die_on_error = 0;
1081         top.do_fgetc = config_buf_fgetc;
1082         top.do_ungetc = config_buf_ungetc;
1083         top.do_ftell = config_buf_ftell;
1084
1085         return do_config_from(&top, fn, data);
1086 }
1087
1088 static int git_config_from_blob_sha1(config_fn_t fn,
1089                                      const char *name,
1090                                      const unsigned char *sha1,
1091                                      void *data)
1092 {
1093         enum object_type type;
1094         char *buf;
1095         unsigned long size;
1096         int ret;
1097
1098         buf = read_sha1_file(sha1, &type, &size);
1099         if (!buf)
1100                 return error("unable to load config blob object '%s'", name);
1101         if (type != OBJ_BLOB) {
1102                 free(buf);
1103                 return error("reference '%s' does not point to a blob", name);
1104         }
1105
1106         ret = git_config_from_buf(fn, name, buf, size, data);
1107         free(buf);
1108
1109         return ret;
1110 }
1111
1112 static int git_config_from_blob_ref(config_fn_t fn,
1113                                     const char *name,
1114                                     void *data)
1115 {
1116         unsigned char sha1[20];
1117
1118         if (get_sha1(name, sha1) < 0)
1119                 return error("unable to resolve config blob '%s'", name);
1120         return git_config_from_blob_sha1(fn, name, sha1, data);
1121 }
1122
1123 const char *git_etc_gitconfig(void)
1124 {
1125         static const char *system_wide;
1126         if (!system_wide)
1127                 system_wide = system_path(ETC_GITCONFIG);
1128         return system_wide;
1129 }
1130
1131 int git_env_bool(const char *k, int def)
1132 {
1133         const char *v = getenv(k);
1134         return v ? git_config_bool(k, v) : def;
1135 }
1136
1137 int git_config_system(void)
1138 {
1139         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
1140 }
1141
1142 int git_config_early(config_fn_t fn, void *data, const char *repo_config)
1143 {
1144         int ret = 0, found = 0;
1145         char *xdg_config = NULL;
1146         char *user_config = NULL;
1147
1148         home_config_paths(&user_config, &xdg_config, "config");
1149
1150         if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK, 0)) {
1151                 ret += git_config_from_file(fn, git_etc_gitconfig(),
1152                                             data);
1153                 found += 1;
1154         }
1155
1156         if (xdg_config && !access_or_die(xdg_config, R_OK, ACCESS_EACCES_OK)) {
1157                 ret += git_config_from_file(fn, xdg_config, data);
1158                 found += 1;
1159         }
1160
1161         if (user_config && !access_or_die(user_config, R_OK, ACCESS_EACCES_OK)) {
1162                 ret += git_config_from_file(fn, user_config, data);
1163                 found += 1;
1164         }
1165
1166         if (repo_config && !access_or_die(repo_config, R_OK, 0)) {
1167                 ret += git_config_from_file(fn, repo_config, data);
1168                 found += 1;
1169         }
1170
1171         switch (git_config_from_parameters(fn, data)) {
1172         case -1: /* error */
1173                 die("unable to parse command-line config");
1174                 break;
1175         case 0: /* found nothing */
1176                 break;
1177         default: /* found at least one item */
1178                 found++;
1179                 break;
1180         }
1181
1182         free(xdg_config);
1183         free(user_config);
1184         return ret == 0 ? found : ret;
1185 }
1186
1187 int git_config_with_options(config_fn_t fn, void *data,
1188                             struct git_config_source *config_source,
1189                             int respect_includes)
1190 {
1191         char *repo_config = NULL;
1192         int ret;
1193         struct config_include_data inc = CONFIG_INCLUDE_INIT;
1194
1195         if (respect_includes) {
1196                 inc.fn = fn;
1197                 inc.data = data;
1198                 fn = git_config_include;
1199                 data = &inc;
1200         }
1201
1202         /*
1203          * If we have a specific filename, use it. Otherwise, follow the
1204          * regular lookup sequence.
1205          */
1206         if (config_source && config_source->use_stdin)
1207                 return git_config_from_stdin(fn, data);
1208         else if (config_source && config_source->file)
1209                 return git_config_from_file(fn, config_source->file, data);
1210         else if (config_source && config_source->blob)
1211                 return git_config_from_blob_ref(fn, config_source->blob, data);
1212
1213         repo_config = git_pathdup("config");
1214         ret = git_config_early(fn, data, repo_config);
1215         if (repo_config)
1216                 free(repo_config);
1217         return ret;
1218 }
1219
1220 int git_config(config_fn_t fn, void *data)
1221 {
1222         return git_config_with_options(fn, data, NULL, 1);
1223 }
1224
1225 /*
1226  * Find all the stuff for git_config_set() below.
1227  */
1228
1229 static struct {
1230         int baselen;
1231         char *key;
1232         int do_not_match;
1233         regex_t *value_regex;
1234         int multi_replace;
1235         size_t *offset;
1236         unsigned int offset_alloc;
1237         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
1238         int seen;
1239 } store;
1240
1241 static int matches(const char *key, const char *value)
1242 {
1243         return !strcmp(key, store.key) &&
1244                 (store.value_regex == NULL ||
1245                  (store.do_not_match ^
1246                   !regexec(store.value_regex, value, 0, NULL, 0)));
1247 }
1248
1249 static int store_aux(const char *key, const char *value, void *cb)
1250 {
1251         const char *ep;
1252         size_t section_len;
1253
1254         switch (store.state) {
1255         case KEY_SEEN:
1256                 if (matches(key, value)) {
1257                         if (store.seen == 1 && store.multi_replace == 0) {
1258                                 warning("%s has multiple values", key);
1259                         }
1260
1261                         ALLOC_GROW(store.offset, store.seen + 1,
1262                                    store.offset_alloc);
1263
1264                         store.offset[store.seen] = cf->do_ftell(cf);
1265                         store.seen++;
1266                 }
1267                 break;
1268         case SECTION_SEEN:
1269                 /*
1270                  * What we are looking for is in store.key (both
1271                  * section and var), and its section part is baselen
1272                  * long.  We found key (again, both section and var).
1273                  * We would want to know if this key is in the same
1274                  * section as what we are looking for.  We already
1275                  * know we are in the same section as what should
1276                  * hold store.key.
1277                  */
1278                 ep = strrchr(key, '.');
1279                 section_len = ep - key;
1280
1281                 if ((section_len != store.baselen) ||
1282                     memcmp(key, store.key, section_len+1)) {
1283                         store.state = SECTION_END_SEEN;
1284                         break;
1285                 }
1286
1287                 /*
1288                  * Do not increment matches: this is no match, but we
1289                  * just made sure we are in the desired section.
1290                  */
1291                 ALLOC_GROW(store.offset, store.seen + 1,
1292                            store.offset_alloc);
1293                 store.offset[store.seen] = cf->do_ftell(cf);
1294                 /* fallthru */
1295         case SECTION_END_SEEN:
1296         case START:
1297                 if (matches(key, value)) {
1298                         ALLOC_GROW(store.offset, store.seen + 1,
1299                                    store.offset_alloc);
1300                         store.offset[store.seen] = cf->do_ftell(cf);
1301                         store.state = KEY_SEEN;
1302                         store.seen++;
1303                 } else {
1304                         if (strrchr(key, '.') - key == store.baselen &&
1305                               !strncmp(key, store.key, store.baselen)) {
1306                                         store.state = SECTION_SEEN;
1307                                         ALLOC_GROW(store.offset,
1308                                                    store.seen + 1,
1309                                                    store.offset_alloc);
1310                                         store.offset[store.seen] = cf->do_ftell(cf);
1311                         }
1312                 }
1313         }
1314         return 0;
1315 }
1316
1317 static int write_error(const char *filename)
1318 {
1319         error("failed to write new configuration file %s", filename);
1320
1321         /* Same error code as "failed to rename". */
1322         return 4;
1323 }
1324
1325 static int store_write_section(int fd, const char *key)
1326 {
1327         const char *dot;
1328         int i, success;
1329         struct strbuf sb = STRBUF_INIT;
1330
1331         dot = memchr(key, '.', store.baselen);
1332         if (dot) {
1333                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
1334                 for (i = dot - key + 1; i < store.baselen; i++) {
1335                         if (key[i] == '"' || key[i] == '\\')
1336                                 strbuf_addch(&sb, '\\');
1337                         strbuf_addch(&sb, key[i]);
1338                 }
1339                 strbuf_addstr(&sb, "\"]\n");
1340         } else {
1341                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
1342         }
1343
1344         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
1345         strbuf_release(&sb);
1346
1347         return success;
1348 }
1349
1350 static int store_write_pair(int fd, const char *key, const char *value)
1351 {
1352         int i, success;
1353         int length = strlen(key + store.baselen + 1);
1354         const char *quote = "";
1355         struct strbuf sb = STRBUF_INIT;
1356
1357         /*
1358          * Check to see if the value needs to be surrounded with a dq pair.
1359          * Note that problematic characters are always backslash-quoted; this
1360          * check is about not losing leading or trailing SP and strings that
1361          * follow beginning-of-comment characters (i.e. ';' and '#') by the
1362          * configuration parser.
1363          */
1364         if (value[0] == ' ')
1365                 quote = "\"";
1366         for (i = 0; value[i]; i++)
1367                 if (value[i] == ';' || value[i] == '#')
1368                         quote = "\"";
1369         if (i && value[i - 1] == ' ')
1370                 quote = "\"";
1371
1372         strbuf_addf(&sb, "\t%.*s = %s",
1373                     length, key + store.baselen + 1, quote);
1374
1375         for (i = 0; value[i]; i++)
1376                 switch (value[i]) {
1377                 case '\n':
1378                         strbuf_addstr(&sb, "\\n");
1379                         break;
1380                 case '\t':
1381                         strbuf_addstr(&sb, "\\t");
1382                         break;
1383                 case '"':
1384                 case '\\':
1385                         strbuf_addch(&sb, '\\');
1386                 default:
1387                         strbuf_addch(&sb, value[i]);
1388                         break;
1389                 }
1390         strbuf_addf(&sb, "%s\n", quote);
1391
1392         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
1393         strbuf_release(&sb);
1394
1395         return success;
1396 }
1397
1398 static ssize_t find_beginning_of_line(const char *contents, size_t size,
1399         size_t offset_, int *found_bracket)
1400 {
1401         size_t equal_offset = size, bracket_offset = size;
1402         ssize_t offset;
1403
1404 contline:
1405         for (offset = offset_-2; offset > 0
1406                         && contents[offset] != '\n'; offset--)
1407                 switch (contents[offset]) {
1408                         case '=': equal_offset = offset; break;
1409                         case ']': bracket_offset = offset; break;
1410                 }
1411         if (offset > 0 && contents[offset-1] == '\\') {
1412                 offset_ = offset;
1413                 goto contline;
1414         }
1415         if (bracket_offset < equal_offset) {
1416                 *found_bracket = 1;
1417                 offset = bracket_offset+1;
1418         } else
1419                 offset++;
1420
1421         return offset;
1422 }
1423
1424 int git_config_set_in_file(const char *config_filename,
1425                         const char *key, const char *value)
1426 {
1427         return git_config_set_multivar_in_file(config_filename, key, value, NULL, 0);
1428 }
1429
1430 int git_config_set(const char *key, const char *value)
1431 {
1432         return git_config_set_multivar(key, value, NULL, 0);
1433 }
1434
1435 /*
1436  * Auxiliary function to sanity-check and split the key into the section
1437  * identifier and variable name.
1438  *
1439  * Returns 0 on success, -1 when there is an invalid character in the key and
1440  * -2 if there is no section name in the key.
1441  *
1442  * store_key - pointer to char* which will hold a copy of the key with
1443  *             lowercase section and variable name
1444  * baselen - pointer to int which will hold the length of the
1445  *           section + subsection part, can be NULL
1446  */
1447 int git_config_parse_key(const char *key, char **store_key, int *baselen_)
1448 {
1449         int i, dot, baselen;
1450         const char *last_dot = strrchr(key, '.');
1451
1452         /*
1453          * Since "key" actually contains the section name and the real
1454          * key name separated by a dot, we have to know where the dot is.
1455          */
1456
1457         if (last_dot == NULL || last_dot == key) {
1458                 error("key does not contain a section: %s", key);
1459                 return -CONFIG_NO_SECTION_OR_NAME;
1460         }
1461
1462         if (!last_dot[1]) {
1463                 error("key does not contain variable name: %s", key);
1464                 return -CONFIG_NO_SECTION_OR_NAME;
1465         }
1466
1467         baselen = last_dot - key;
1468         if (baselen_)
1469                 *baselen_ = baselen;
1470
1471         /*
1472          * Validate the key and while at it, lower case it for matching.
1473          */
1474         *store_key = xmalloc(strlen(key) + 1);
1475
1476         dot = 0;
1477         for (i = 0; key[i]; i++) {
1478                 unsigned char c = key[i];
1479                 if (c == '.')
1480                         dot = 1;
1481                 /* Leave the extended basename untouched.. */
1482                 if (!dot || i > baselen) {
1483                         if (!iskeychar(c) ||
1484                             (i == baselen + 1 && !isalpha(c))) {
1485                                 error("invalid key: %s", key);
1486                                 goto out_free_ret_1;
1487                         }
1488                         c = tolower(c);
1489                 } else if (c == '\n') {
1490                         error("invalid key (newline): %s", key);
1491                         goto out_free_ret_1;
1492                 }
1493                 (*store_key)[i] = c;
1494         }
1495         (*store_key)[i] = 0;
1496
1497         return 0;
1498
1499 out_free_ret_1:
1500         free(*store_key);
1501         *store_key = NULL;
1502         return -CONFIG_INVALID_KEY;
1503 }
1504
1505 /*
1506  * If value==NULL, unset in (remove from) config,
1507  * if value_regex!=NULL, disregard key/value pairs where value does not match.
1508  * if multi_replace==0, nothing, or only one matching key/value is replaced,
1509  *     else all matching key/values (regardless how many) are removed,
1510  *     before the new pair is written.
1511  *
1512  * Returns 0 on success.
1513  *
1514  * This function does this:
1515  *
1516  * - it locks the config file by creating ".git/config.lock"
1517  *
1518  * - it then parses the config using store_aux() as validator to find
1519  *   the position on the key/value pair to replace. If it is to be unset,
1520  *   it must be found exactly once.
1521  *
1522  * - the config file is mmap()ed and the part before the match (if any) is
1523  *   written to the lock file, then the changed part and the rest.
1524  *
1525  * - the config file is removed and the lock file rename()d to it.
1526  *
1527  */
1528 int git_config_set_multivar_in_file(const char *config_filename,
1529                                 const char *key, const char *value,
1530                                 const char *value_regex, int multi_replace)
1531 {
1532         int fd = -1, in_fd;
1533         int ret;
1534         struct lock_file *lock = NULL;
1535         char *filename_buf = NULL;
1536
1537         /* parse-key returns negative; flip the sign to feed exit(3) */
1538         ret = 0 - git_config_parse_key(key, &store.key, &store.baselen);
1539         if (ret)
1540                 goto out_free;
1541
1542         store.multi_replace = multi_replace;
1543
1544         if (!config_filename)
1545                 config_filename = filename_buf = git_pathdup("config");
1546
1547         /*
1548          * The lock serves a purpose in addition to locking: the new
1549          * contents of .git/config will be written into it.
1550          */
1551         lock = xcalloc(1, sizeof(struct lock_file));
1552         fd = hold_lock_file_for_update(lock, config_filename, 0);
1553         if (fd < 0) {
1554                 error("could not lock config file %s: %s", config_filename, strerror(errno));
1555                 free(store.key);
1556                 ret = CONFIG_NO_LOCK;
1557                 goto out_free;
1558         }
1559
1560         /*
1561          * If .git/config does not exist yet, write a minimal version.
1562          */
1563         in_fd = open(config_filename, O_RDONLY);
1564         if ( in_fd < 0 ) {
1565                 free(store.key);
1566
1567                 if ( ENOENT != errno ) {
1568                         error("opening %s: %s", config_filename,
1569                               strerror(errno));
1570                         ret = CONFIG_INVALID_FILE; /* same as "invalid config file" */
1571                         goto out_free;
1572                 }
1573                 /* if nothing to unset, error out */
1574                 if (value == NULL) {
1575                         ret = CONFIG_NOTHING_SET;
1576                         goto out_free;
1577                 }
1578
1579                 store.key = (char *)key;
1580                 if (!store_write_section(fd, key) ||
1581                     !store_write_pair(fd, key, value))
1582                         goto write_err_out;
1583         } else {
1584                 struct stat st;
1585                 char *contents;
1586                 size_t contents_sz, copy_begin, copy_end;
1587                 int i, new_line = 0;
1588
1589                 if (value_regex == NULL)
1590                         store.value_regex = NULL;
1591                 else {
1592                         if (value_regex[0] == '!') {
1593                                 store.do_not_match = 1;
1594                                 value_regex++;
1595                         } else
1596                                 store.do_not_match = 0;
1597
1598                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
1599                         if (regcomp(store.value_regex, value_regex,
1600                                         REG_EXTENDED)) {
1601                                 error("invalid pattern: %s", value_regex);
1602                                 free(store.value_regex);
1603                                 ret = CONFIG_INVALID_PATTERN;
1604                                 goto out_free;
1605                         }
1606                 }
1607
1608                 ALLOC_GROW(store.offset, 1, store.offset_alloc);
1609                 store.offset[0] = 0;
1610                 store.state = START;
1611                 store.seen = 0;
1612
1613                 /*
1614                  * After this, store.offset will contain the *end* offset
1615                  * of the last match, or remain at 0 if no match was found.
1616                  * As a side effect, we make sure to transform only a valid
1617                  * existing config file.
1618                  */
1619                 if (git_config_from_file(store_aux, config_filename, NULL)) {
1620                         error("invalid config file %s", config_filename);
1621                         free(store.key);
1622                         if (store.value_regex != NULL) {
1623                                 regfree(store.value_regex);
1624                                 free(store.value_regex);
1625                         }
1626                         ret = CONFIG_INVALID_FILE;
1627                         goto out_free;
1628                 }
1629
1630                 free(store.key);
1631                 if (store.value_regex != NULL) {
1632                         regfree(store.value_regex);
1633                         free(store.value_regex);
1634                 }
1635
1636                 /* if nothing to unset, or too many matches, error out */
1637                 if ((store.seen == 0 && value == NULL) ||
1638                                 (store.seen > 1 && multi_replace == 0)) {
1639                         ret = CONFIG_NOTHING_SET;
1640                         goto out_free;
1641                 }
1642
1643                 fstat(in_fd, &st);
1644                 contents_sz = xsize_t(st.st_size);
1645                 contents = xmmap(NULL, contents_sz, PROT_READ,
1646                         MAP_PRIVATE, in_fd, 0);
1647                 close(in_fd);
1648
1649                 if (store.seen == 0)
1650                         store.seen = 1;
1651
1652                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1653                         if (store.offset[i] == 0) {
1654                                 store.offset[i] = copy_end = contents_sz;
1655                         } else if (store.state != KEY_SEEN) {
1656                                 copy_end = store.offset[i];
1657                         } else
1658                                 copy_end = find_beginning_of_line(
1659                                         contents, contents_sz,
1660                                         store.offset[i]-2, &new_line);
1661
1662                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1663                                 new_line = 1;
1664
1665                         /* write the first part of the config */
1666                         if (copy_end > copy_begin) {
1667                                 if (write_in_full(fd, contents + copy_begin,
1668                                                   copy_end - copy_begin) <
1669                                     copy_end - copy_begin)
1670                                         goto write_err_out;
1671                                 if (new_line &&
1672                                     write_str_in_full(fd, "\n") != 1)
1673                                         goto write_err_out;
1674                         }
1675                         copy_begin = store.offset[i];
1676                 }
1677
1678                 /* write the pair (value == NULL means unset) */
1679                 if (value != NULL) {
1680                         if (store.state == START) {
1681                                 if (!store_write_section(fd, key))
1682                                         goto write_err_out;
1683                         }
1684                         if (!store_write_pair(fd, key, value))
1685                                 goto write_err_out;
1686                 }
1687
1688                 /* write the rest of the config */
1689                 if (copy_begin < contents_sz)
1690                         if (write_in_full(fd, contents + copy_begin,
1691                                           contents_sz - copy_begin) <
1692                             contents_sz - copy_begin)
1693                                 goto write_err_out;
1694
1695                 munmap(contents, contents_sz);
1696         }
1697
1698         if (commit_lock_file(lock) < 0) {
1699                 error("could not commit config file %s", config_filename);
1700                 ret = CONFIG_NO_WRITE;
1701                 goto out_free;
1702         }
1703
1704         /*
1705          * lock is committed, so don't try to roll it back below.
1706          * NOTE: Since lockfile.c keeps a linked list of all created
1707          * lock_file structures, it isn't safe to free(lock).  It's
1708          * better to just leave it hanging around.
1709          */
1710         lock = NULL;
1711         ret = 0;
1712
1713 out_free:
1714         if (lock)
1715                 rollback_lock_file(lock);
1716         free(filename_buf);
1717         return ret;
1718
1719 write_err_out:
1720         ret = write_error(lock->filename);
1721         goto out_free;
1722
1723 }
1724
1725 int git_config_set_multivar(const char *key, const char *value,
1726                         const char *value_regex, int multi_replace)
1727 {
1728         return git_config_set_multivar_in_file(NULL, key, value, value_regex,
1729                                                multi_replace);
1730 }
1731
1732 static int section_name_match (const char *buf, const char *name)
1733 {
1734         int i = 0, j = 0, dot = 0;
1735         if (buf[i] != '[')
1736                 return 0;
1737         for (i = 1; buf[i] && buf[i] != ']'; i++) {
1738                 if (!dot && isspace(buf[i])) {
1739                         dot = 1;
1740                         if (name[j++] != '.')
1741                                 break;
1742                         for (i++; isspace(buf[i]); i++)
1743                                 ; /* do nothing */
1744                         if (buf[i] != '"')
1745                                 break;
1746                         continue;
1747                 }
1748                 if (buf[i] == '\\' && dot)
1749                         i++;
1750                 else if (buf[i] == '"' && dot) {
1751                         for (i++; isspace(buf[i]); i++)
1752                                 ; /* do_nothing */
1753                         break;
1754                 }
1755                 if (buf[i] != name[j++])
1756                         break;
1757         }
1758         if (buf[i] == ']' && name[j] == 0) {
1759                 /*
1760                  * We match, now just find the right length offset by
1761                  * gobbling up any whitespace after it, as well
1762                  */
1763                 i++;
1764                 for (; buf[i] && isspace(buf[i]); i++)
1765                         ; /* do nothing */
1766                 return i;
1767         }
1768         return 0;
1769 }
1770
1771 static int section_name_is_ok(const char *name)
1772 {
1773         /* Empty section names are bogus. */
1774         if (!*name)
1775                 return 0;
1776
1777         /*
1778          * Before a dot, we must be alphanumeric or dash. After the first dot,
1779          * anything goes, so we can stop checking.
1780          */
1781         for (; *name && *name != '.'; name++)
1782                 if (*name != '-' && !isalnum(*name))
1783                         return 0;
1784         return 1;
1785 }
1786
1787 /* if new_name == NULL, the section is removed instead */
1788 int git_config_rename_section_in_file(const char *config_filename,
1789                                       const char *old_name, const char *new_name)
1790 {
1791         int ret = 0, remove = 0;
1792         char *filename_buf = NULL;
1793         struct lock_file *lock;
1794         int out_fd;
1795         char buf[1024];
1796         FILE *config_file;
1797
1798         if (new_name && !section_name_is_ok(new_name)) {
1799                 ret = error("invalid section name: %s", new_name);
1800                 goto out;
1801         }
1802
1803         if (!config_filename)
1804                 config_filename = filename_buf = git_pathdup("config");
1805
1806         lock = xcalloc(1, sizeof(struct lock_file));
1807         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1808         if (out_fd < 0) {
1809                 ret = error("could not lock config file %s", config_filename);
1810                 goto out;
1811         }
1812
1813         if (!(config_file = fopen(config_filename, "rb"))) {
1814                 /* no config file means nothing to rename, no error */
1815                 goto unlock_and_out;
1816         }
1817
1818         while (fgets(buf, sizeof(buf), config_file)) {
1819                 int i;
1820                 int length;
1821                 char *output = buf;
1822                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1823                         ; /* do nothing */
1824                 if (buf[i] == '[') {
1825                         /* it's a section */
1826                         int offset = section_name_match(&buf[i], old_name);
1827                         if (offset > 0) {
1828                                 ret++;
1829                                 if (new_name == NULL) {
1830                                         remove = 1;
1831                                         continue;
1832                                 }
1833                                 store.baselen = strlen(new_name);
1834                                 if (!store_write_section(out_fd, new_name)) {
1835                                         ret = write_error(lock->filename);
1836                                         goto out;
1837                                 }
1838                                 /*
1839                                  * We wrote out the new section, with
1840                                  * a newline, now skip the old
1841                                  * section's length
1842                                  */
1843                                 output += offset + i;
1844                                 if (strlen(output) > 0) {
1845                                         /*
1846                                          * More content means there's
1847                                          * a declaration to put on the
1848                                          * next line; indent with a
1849                                          * tab
1850                                          */
1851                                         output -= 1;
1852                                         output[0] = '\t';
1853                                 }
1854                         }
1855                         remove = 0;
1856                 }
1857                 if (remove)
1858                         continue;
1859                 length = strlen(output);
1860                 if (write_in_full(out_fd, output, length) != length) {
1861                         ret = write_error(lock->filename);
1862                         goto out;
1863                 }
1864         }
1865         fclose(config_file);
1866 unlock_and_out:
1867         if (commit_lock_file(lock) < 0)
1868                 ret = error("could not commit config file %s", config_filename);
1869 out:
1870         free(filename_buf);
1871         return ret;
1872 }
1873
1874 int git_config_rename_section(const char *old_name, const char *new_name)
1875 {
1876         return git_config_rename_section_in_file(NULL, old_name, new_name);
1877 }
1878
1879 /*
1880  * Call this to report error for your variable that should not
1881  * get a boolean value (i.e. "[my] var" means "true").
1882  */
1883 #undef config_error_nonbool
1884 int config_error_nonbool(const char *var)
1885 {
1886         return error("Missing value for '%s'", var);
1887 }
1888
1889 int parse_config_key(const char *var,
1890                      const char *section,
1891                      const char **subsection, int *subsection_len,
1892                      const char **key)
1893 {
1894         int section_len = strlen(section);
1895         const char *dot;
1896
1897         /* Does it start with "section." ? */
1898         if (!starts_with(var, section) || var[section_len] != '.')
1899                 return -1;
1900
1901         /*
1902          * Find the key; we don't know yet if we have a subsection, but we must
1903          * parse backwards from the end, since the subsection may have dots in
1904          * it, too.
1905          */
1906         dot = strrchr(var, '.');
1907         *key = dot + 1;
1908
1909         /* Did we have a subsection at all? */
1910         if (dot == var + section_len) {
1911                 *subsection = NULL;
1912                 *subsection_len = 0;
1913         }
1914         else {
1915                 *subsection = var + section_len + 1;
1916                 *subsection_len = dot - *subsection;
1917         }
1918
1919         return 0;
1920 }