php-systzdata.patch

   1 # License: MIT
   2 # http://opensource.org/licenses/MIT
   3
   4 Add support for use of the system timezone database, rather
   5 than embedding a copy.  Discussed upstream but was not desired.
   6
   7 History:
   8 r21: adapt for timelib 2021.03 (in 8.1.0)
   9 r20: adapt for timelib 2020.03 (in 8.0.10RC1)
  10 r19: adapt for timelib 2020.02 (in 8.0.0beta2)
  11 r18: adapt for autotool change in 7.3.3RC1
  12 r17: adapt for timelib 2018.01 (in 7.3.2RC1)
  13 r16: adapt for timelib 2017.06 (in 7.2.3RC1)
  14 r15: adapt for timelib 2017.05beta7 (in 7.2.0RC1)
  15 r14: improve check for valid tz file
  16 r13: adapt for upstream changes to use PHP allocator
  17 r12: adapt for upstream changes for new zic
  18 r11: use canonical names to avoid more case sensitivity issues
  19      round lat/long from zone.tab towards zero per builtin db
  20 r10: make timezone case insensitive
  21 r9: fix another compile error without --with-system-tzdata configured (Michael Heimpold)
  22 r8: fix compile error without --with-system-tzdata configured
  23 r7: improve check for valid timezone id to exclude directories
  24 r6: fix fd leak in r5, fix country code/BC flag use in
  25     timezone_identifiers_list() using system db,
  26     fix use of PECL timezonedb to override system db,
  27 r5: reverts addition of "System/Localtime" fake tzname.
  28     updated for 5.3.0, parses zone.tab to pick up mapping between
  29     timezone name, country code and long/lat coords
  30 r4: added "System/Localtime" tzname which uses /etc/localtime
  31 r3: fix a crash if /usr/share/zoneinfo doesn't exist (Raphael Geissert)
  32 r2: add filesystem trawl to set up name alias index
  33 r1: initial revision
  34
  35 diff -up php-8.0.0beta3/ext/date/config0.m4.systzdata php-8.0.0beta3/ext/date/config0.m4
  36 --- php-8.0.0beta3/ext/date/config0.m4.systzdata        2020-09-01 19:13:26.000000000 +0200
  37 +++ php-8.0.0beta3/ext/date/config0.m4  2020-09-02 08:07:51.039979873 +0200
  38 @@ -4,6 +4,19 @@ AC_CHECK_HEADERS([io.h])
  39  dnl Check for strtoll, atoll
  40  AC_CHECK_FUNCS(strtoll atoll)
  41
  42 +PHP_ARG_WITH(system-tzdata, for use of system timezone data,
  43 +[  --with-system-tzdata[=DIR]      to specify use of system timezone data],
  44 +no, no)
  45 +
  46 +if test "$PHP_SYSTEM_TZDATA" != "no"; then
  47 +   AC_DEFINE(HAVE_SYSTEM_TZDATA, 1, [Define if system timezone data is used])
  48 +
  49 +   if test "$PHP_SYSTEM_TZDATA" != "yes"; then
  50 +      AC_DEFINE_UNQUOTED(HAVE_SYSTEM_TZDATA_PREFIX, "$PHP_SYSTEM_TZDATA",
  51 +                         [Define for location of system timezone data])
  52 +   fi
  53 +fi
  54 +
  55  PHP_DATE_CFLAGS="-Wno-implicit-fallthrough -I@ext_builddir@/lib -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1 -DHAVE_TIMELIB_CONFIG_H=1"
  56  timelib_sources="lib/astro.c lib/dow.c lib/parse_date.c lib/parse_tz.c lib/parse_posix.c
  57                   lib/timelib.c lib/tm2unixtime.c lib/unixtime2tm.c lib/parse_iso_intervals.c lib/interval.c"
  58 diff -up php-8.0.0beta3/ext/date/lib/parse_tz.c.systzdata php-8.0.0beta3/ext/date/lib/parse_tz.c
  59 --- php-8.0.0beta3/ext/date/lib/parse_tz.c.systzdata    2020-09-01 19:13:26.000000000 +0200
  60 +++ php-8.0.0beta3/ext/date/lib/parse_tz.c      2020-09-02 08:07:51.039979873 +0200
  61 @@ -26,9 +26,22 @@
  62  #include "timelib.h"
  63  #include "timelib_private.h"
  64
  65 +#ifdef HAVE_SYSTEM_TZDATA
  66 +#include <sys/mman.h>
  67 +#include <sys/stat.h>
  68 +#include <limits.h>
  69 +#include <fcntl.h>
  70 +#include <unistd.h>
  71 +
  72 +#include "php_scandir.h"
  73 +
  74 +#else
  75  #define TIMELIB_SUPPORTS_V2DATA
  76  #define TIMELIB_SUPPORT_SLIM_FILE
  77  #include "timezonedb.h"
  78 +#endif
  79 +
  80 +#include <ctype.h>
  81
  82  #if (defined(__APPLE__) || defined(__APPLE_CC__)) && (defined(__BIG_ENDIAN__) || defined(__LITTLE_ENDIAN__))
  83  # if defined(__LITTLE_ENDIAN__)
  84 @@ -95,6 +108,11 @@ static int read_php_preamble(const unsig
  85  {
  86         uint32_t version;
  87
  88 +       if (memcmp(*tzf, "TZif", 4) == 0) {
  89 +               *tzf += 20;
  90 +               return 0;
  91 +       }
  92 +
  93         /* read ID */
  94         version = (*tzf)[3] - '0';
  95         *tzf += 4;
  96 @@ -577,7 +595,429 @@ void timelib_dump_tzinfo(timelib_tzinfo
  97         }
  98  }
  99
 100 -static int seek_to_tz_position(const unsigned char **tzf, const char *timezone, const timelib_tzdb *tzdb)
 101 +#ifdef HAVE_SYSTEM_TZDATA
 102 +
 103 +#ifdef HAVE_SYSTEM_TZDATA_PREFIX
 104 +#define ZONEINFO_PREFIX HAVE_SYSTEM_TZDATA_PREFIX
 105 +#else
 106 +#define ZONEINFO_PREFIX "/usr/share/zoneinfo"
 107 +#endif
 108 +
 109 +/* System timezone database pointer. */
 110 +static const timelib_tzdb *timezonedb_system;
 111 +
 112 +/* Hash table entry for the cache of the zone.tab mapping table. */
 113 +struct location_info {
 114 +        char code[2];
 115 +        double latitude, longitude;
 116 +        char name[64];
 117 +        char *comment;
 118 +        struct location_info *next;
 119 +};
 120 +
 121 +/* Cache of zone.tab. */
 122 +static struct location_info **system_location_table;
 123 +
 124 +/* Size of the zone.tab hash table; a random-ish prime big enough to
 125 + * prevent too many collisions. */
 126 +#define LOCINFO_HASH_SIZE (1021)
 127 +
 128 +/* Compute a case insensitive hash of str */
 129 +static uint32_t tz_hash(const char *str)
 130 +{
 131 +    const unsigned char *p = (const unsigned char *)str;
 132 +    uint32_t hash = 5381;
 133 +    int c;
 134 +
 135 +    while ((c = tolower(*p++)) != '\0') {
 136 +        hash = (hash << 5) ^ hash ^ c;
 137 +    }
 138 +
 139 +    return hash % LOCINFO_HASH_SIZE;
 140 +}
 141 +
 142 +/* Parse an ISO-6709 date as used in zone.tab. Returns end of the
 143 + * parsed string on success, or NULL on parse error.  On success,
 144 + * writes the parsed number to *result. */
 145 +static char *parse_iso6709(char *p, double *result)
 146 +{
 147 +    double v, sign;
 148 +    char *pend;
 149 +    size_t len;
 150 +
 151 +    if (*p == '+')
 152 +        sign = 1.0;
 153 +    else if (*p == '-')
 154 +        sign = -1.0;
 155 +    else
 156 +        return NULL;
 157 +
 158 +    p++;
 159 +    for (pend = p; *pend >= '0' && *pend <= '9'; pend++)
 160 +        ;;
 161 +
 162 +    /* Annoying encoding used by zone.tab has no decimal point, so use
 163 +     * the length to determine the format:
 164 +     *
 165 +     * 4 = DDMM
 166 +     * 5 = DDDMM
 167 +     * 6 = DDMMSS
 168 +     * 7 = DDDMMSS
 169 +     */
 170 +    len = pend - p;
 171 +    if (len < 4 || len > 7) {
 172 +        return NULL;
 173 +    }
 174 +
 175 +    /* p => [D]DD */
 176 +    v = (p[0] - '0') * 10.0 + (p[1] - '0');
 177 +    p += 2;
 178 +    if (len == 5 || len == 7)
 179 +        v = v * 10.0 + (*p++ - '0');
 180 +    /* p => MM[SS] */
 181 +    v += (10.0 * (p[0] - '0')
 182 +          + p[1] - '0') / 60.0;
 183 +    p += 2;
 184 +    /* p => [SS] */
 185 +    if (len > 5) {
 186 +        v += (10.0 * (p[0] - '0')
 187 +              + p[1] - '0') / 3600.0;
 188 +        p += 2;
 189 +    }
 190 +
 191 +    /* Round to five decimal place, not because it's a good idea,
 192 +     * but, because the builtin data uses rounded data, so, match
 193 +     * that. */
 194 +    *result = trunc(v * sign * 100000.0) / 100000.0;
 195 +
 196 +    return p;
 197 +}
 198 +
 199 +/* This function parses the zone.tab file to build up the mapping of
 200 + * timezone to country code and geographic location, and returns a
 201 + * hash table.  The hash table is indexed by the function:
 202 + *
 203 + *   tz_hash(timezone-name)
 204 + */
 205 +static struct location_info **create_location_table(void)
 206 +{
 207 +    struct location_info **li, *i;
 208 +    char zone_tab[PATH_MAX];
 209 +    char line[512];
 210 +    FILE *fp;
 211 +
 212 +    strncpy(zone_tab, ZONEINFO_PREFIX "/zone.tab", sizeof zone_tab);
 213 +
 214 +    fp = fopen(zone_tab, "r");
 215 +    if (!fp) {
 216 +        return NULL;
 217 +    }
 218 +
 219 +    li = calloc(LOCINFO_HASH_SIZE, sizeof *li);
 220 +
 221 +    while (fgets(line, sizeof line, fp)) {
 222 +        char *p = line, *code, *name, *comment;
 223 +        uint32_t hash;
 224 +        double latitude, longitude;
 225 +
 226 +        while (isspace(*p))
 227 +            p++;
 228 +
 229 +        if (*p == '#' || *p == '\0' || *p == '\n')
 230 +            continue;
 231 +
 232 +        if (!isalpha(p[0]) || !isalpha(p[1]) || p[2] != '\t')
 233 +            continue;
 234 +
 235 +        /* code => AA */
 236 +        code = p;
 237 +        p[2] = 0;
 238 +        p += 3;
 239 +
 240 +        /* coords => [+-][D]DDMM[SS][+-][D]DDMM[SS] */
 241 +        p = parse_iso6709(p, &latitude);
 242 +        if (!p) {
 243 +            continue;
 244 +        }
 245 +        p = parse_iso6709(p, &longitude);
 246 +        if (!p) {
 247 +            continue;
 248 +        }
 249 +
 250 +        if (!p || *p != '\t') {
 251 +            continue;
 252 +        }
 253 +
 254 +        /* name = string */
 255 +        name = ++p;
 256 +        while (*p != '\t' && *p && *p != '\n')
 257 +            p++;
 258 +
 259 +        *p++ = '\0';
 260 +
 261 +        /* comment = string */
 262 +        comment = p;
 263 +        while (*p != '\t' && *p && *p != '\n')
 264 +            p++;
 265 +
 266 +        if (*p == '\n' || *p == '\t')
 267 +            *p = '\0';
 268 +
 269 +        hash = tz_hash(name);
 270 +        i = malloc(sizeof *i);
 271 +        memcpy(i->code, code, 2);
 272 +        strncpy(i->name, name, sizeof i->name);
 273 +        i->comment = strdup(comment);
 274 +        i->longitude = longitude;
 275 +        i->latitude = latitude;
 276 +        i->next = li[hash];
 277 +        li[hash] = i;
 278 +        /* printf("%s [%u, %f, %f]\n", name, hash, latitude, longitude); */
 279 +    }
 280 +
 281 +    fclose(fp);
 282 +
 283 +    return li;
 284 +}
 285 +
 286 +/* Return location info from hash table, using given timezone name.
 287 + * Returns NULL if the name could not be found. */
 288 +const struct location_info *find_zone_info(struct location_info **li,
 289 +                                           const char *name)
 290 +{
 291 +    uint32_t hash = tz_hash(name);
 292 +    const struct location_info *l;
 293 +
 294 +    if (!li) {
 295 +        return NULL;
 296 +    }
 297 +
 298 +    for (l = li[hash]; l; l = l->next) {
 299 +        if (timelib_strcasecmp(l->name, name) == 0)
 300 +            return l;
 301 +    }
 302 +
 303 +    return NULL;
 304 +}
 305 +
 306 +/* Filter out some non-tzdata files and the posix/right databases, if
 307 + * present. */
 308 +static int index_filter(const struct dirent *ent)
 309 +{
 310 +       return strcmp(ent->d_name, ".") != 0
 311 +               && strcmp(ent->d_name, "..") != 0
 312 +               && strcmp(ent->d_name, "posix") != 0
 313 +               && strcmp(ent->d_name, "posixrules") != 0
 314 +               && strcmp(ent->d_name, "right") != 0
 315 +               && strstr(ent->d_name, ".list") == NULL
 316 +               && strstr(ent->d_name, ".tab") == NULL;
 317 +}
 318 +
 319 +static int sysdbcmp(const void *first, const void *second)
 320 +{
 321 +        const timelib_tzdb_index_entry *alpha = first, *beta = second;
 322 +
 323 +        return timelib_strcasecmp(alpha->id, beta->id);
 324 +}
 325 +
 326 +
 327 +/* Create the zone identifier index by trawling the filesystem. */
 328 +static void create_zone_index(timelib_tzdb *db)
 329 +{
 330 +       size_t dirstack_size,  dirstack_top;
 331 +       size_t index_size, index_next;
 332 +       timelib_tzdb_index_entry *db_index;
 333 +       char **dirstack;
 334 +
 335 +       /* LIFO stack to hold directory entries to scan; each slot is a
 336 +        * directory name relative to the zoneinfo prefix. */
 337 +       dirstack_size = 32;
 338 +       dirstack = malloc(dirstack_size * sizeof *dirstack);
 339 +       dirstack_top = 1;
 340 +       dirstack[0] = strdup("");
 341 +
 342 +       /* Index array. */
 343 +       index_size = 64;
 344 +       db_index = malloc(index_size * sizeof *db_index);
 345 +       index_next = 0;
 346 +
 347 +       do {
 348 +               struct dirent **ents;
 349 +               char name[PATH_MAX], *top;
 350 +               int count;
 351 +
 352 +               /* Pop the top stack entry, and iterate through its contents. */
 353 +               top = dirstack[--dirstack_top];
 354 +               snprintf(name, sizeof name, ZONEINFO_PREFIX "/%s", top);
 355 +
 356 +               count = php_scandir(name, &ents, index_filter, php_alphasort);
 357 +
 358 +               while (count > 0) {
 359 +                       struct stat st;
 360 +                       const char *leaf = ents[count - 1]->d_name;
 361 +
 362 +                       snprintf(name, sizeof name, ZONEINFO_PREFIX "/%s/%s",
 363 +                                top, leaf);
 364 +
 365 +                       if (strlen(name) && stat(name, &st) == 0) {
 366 +                               /* Name, relative to the zoneinfo prefix. */
 367 +                               const char *root = top;
 368 +
 369 +                               if (root[0] == '/') root++;
 370 +
 371 +                               snprintf(name, sizeof name, "%s%s%s", root,
 372 +                                        *root ? "/": "", leaf);
 373 +
 374 +                               if (S_ISDIR(st.st_mode)) {
 375 +                                       if (dirstack_top == dirstack_size) {
 376 +                                               dirstack_size *= 2;
 377 +                                               dirstack = realloc(dirstack,
 378 +                                                                  dirstack_size * sizeof *dirstack);
 379 +                                       }
 380 +                                       dirstack[dirstack_top++] = strdup(name);
 381 +                               }
 382 +                               else {
 383 +                                       if (index_next == index_size) {
 384 +                                               index_size *= 2;
 385 +                                               db_index = realloc(db_index,
 386 +                                                                  index_size * sizeof *db_index);
 387 +                                       }
 388 +
 389 +                                       db_index[index_next++].id = strdup(name);
 390 +                               }
 391 +                       }
 392 +
 393 +                       free(ents[--count]);
 394 +               }
 395 +
 396 +               if (count != -1) free(ents);
 397 +               free(top);
 398 +       } while (dirstack_top);
 399 +
 400 +        qsort(db_index, index_next, sizeof *db_index, sysdbcmp);
 401 +
 402 +       db->index = db_index;
 403 +       db->index_size = index_next;
 404 +
 405 +       free(dirstack);
 406 +}
 407 +
 408 +#define FAKE_HEADER "1234\0??\1??"
 409 +#define FAKE_UTC_POS (7 - 4)
 410 +
 411 +/* Create a fake data segment for database 'sysdb'. */
 412 +static void fake_data_segment(timelib_tzdb *sysdb,
 413 +                              struct location_info **info)
 414 +{
 415 +        size_t n;
 416 +        char *data, *p;
 417 +
 418 +        data = malloc(3 * sysdb->index_size + 7);
 419 +
 420 +        p = mempcpy(data, FAKE_HEADER, sizeof(FAKE_HEADER) - 1);
 421 +
 422 +        for (n = 0; n < sysdb->index_size; n++) {
 423 +                const struct location_info *li;
 424 +                timelib_tzdb_index_entry *ent;
 425 +
 426 +                ent = (timelib_tzdb_index_entry *)&sysdb->index[n];
 427 +
 428 +                /* Lookup the timezone name in the hash table. */
 429 +                if (strcmp(ent->id, "UTC") == 0) {
 430 +                        ent->pos = FAKE_UTC_POS;
 431 +                        continue;
 432 +                }
 433 +
 434 +                li = find_zone_info(info, ent->id);
 435 +                if (li) {
 436 +                        /* If found, append the BC byte and the
 437 +                         * country code; set the position for this
 438 +                         * section of timezone data.  */
 439 +                        ent->pos = (p - data) - 4;
 440 +                        *p++ = '\1';
 441 +                        *p++ = li->code[0];
 442 +                        *p++ = li->code[1];
 443 +                }
 444 +                else {
 445 +                        /* If not found, the timezone data can
 446 +                         * point at the header. */
 447 +                        ent->pos = 0;
 448 +                }
 449 +        }
 450 +
 451 +        sysdb->data = (unsigned char *)data;
 452 +}
 453 +
 454 +/* Returns true if the passed-in stat structure describes a
 455 + * probably-valid timezone file. */
 456 +static int is_valid_tzfile(const struct stat *st, int fd)
 457 +{
 458 +       if (fd) {
 459 +               char buf[20];
 460 +               if (read(fd, buf, 20)!=20) {
 461 +                       return 0;
 462 +               }
 463 +               lseek(fd, SEEK_SET, 0);
 464 +               if (memcmp(buf, "TZif", 4)) {
 465 +                       return 0;
 466 +               }
 467 +       }
 468 +       return S_ISREG(st->st_mode) && st->st_size > 20;
 469 +}
 470 +
 471 +/* To allow timezone names to be used case-insensitively, find the
 472 + * canonical name for this timezone, if possible. */
 473 +static const char *canonical_tzname(const char *timezone)
 474 +{
 475 +    if (timezonedb_system) {
 476 +        timelib_tzdb_index_entry *ent, lookup;
 477 +
 478 +        lookup.id = (char *)timezone;
 479 +
 480 +        ent = bsearch(&lookup, timezonedb_system->index,
 481 +                      timezonedb_system->index_size, sizeof lookup,
 482 +                      sysdbcmp);
 483 +        if (ent) {
 484 +            return ent->id;
 485 +        }
 486 +    }
 487 +
 488 +    return timezone;
 489 +}
 490 +
 491 +/* Return the mmap()ed tzfile if found, else NULL.  On success, the
 492 + * length of the mapped data is placed in *length. */
 493 +static char *map_tzfile(const char *timezone, size_t *length)
 494 +{
 495 +       char fname[PATH_MAX];
 496 +       struct stat st;
 497 +       char *p;
 498 +       int fd;
 499 +
 500 +       if (timezone[0] == '\0' || strstr(timezone, "..") != NULL) {
 501 +               return NULL;
 502 +       }
 503 +
 504 +       snprintf(fname, sizeof fname, ZONEINFO_PREFIX "/%s", canonical_tzname(timezone));
 505 +
 506 +       fd = open(fname, O_RDONLY);
 507 +       if (fd == -1) {
 508 +               return NULL;
 509 +       } else if (fstat(fd, &st) != 0 || !is_valid_tzfile(&st, fd)) {
 510 +               close(fd);
 511 +               return NULL;
 512 +       }
 513 +
 514 +       *length = st.st_size;
 515 +       p = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
 516 +       close(fd);
 517 +
 518 +       return p != MAP_FAILED ? p : NULL;
 519 +}
 520 +
 521 +#endif
 522 +
 523 +static int inmem_seek_to_tz_position(const unsigned char **tzf, const char *timezone, const timelib_tzdb *tzdb)
 524  {
 525         int left = 0, right = tzdb->index_size - 1;
 526
 527 @@ -603,9 +1043,48 @@ static int seek_to_tz_position(const uns
 528         return 0;
 529  }
 530
 531 +static int seek_to_tz_position(const unsigned char **tzf, const char *timezone,
 532 +                              char **map, size_t *maplen,
 533 +                              const timelib_tzdb *tzdb)
 534 +{
 535 +#ifdef HAVE_SYSTEM_TZDATA
 536 +       if (tzdb == timezonedb_system) {
 537 +               char *orig;
 538 +
 539 +               orig = map_tzfile(timezone, maplen);
 540 +               if (orig == NULL) {
 541 +                       return 0;
 542 +               }
 543 +
 544 +               (*tzf) = (unsigned char *)orig;
 545 +               *map = orig;
 546 +        return 1;
 547 +       }
 548 +       else
 549 +#endif
 550 +       {
 551 +               return inmem_seek_to_tz_position(tzf, timezone, tzdb);
 552 +       }
 553 +}
 554 +
 555  const timelib_tzdb *timelib_builtin_db(void)
 556  {
 557 +#ifdef HAVE_SYSTEM_TZDATA
 558 +       if (timezonedb_system == NULL) {
 559 +               timelib_tzdb *tmp = malloc(sizeof *tmp);
 560 +
 561 +               tmp->version = "0.system";
 562 +               tmp->data = NULL;
 563 +               create_zone_index(tmp);
 564 +               system_location_table = create_location_table();
 565 +               fake_data_segment(tmp, system_location_table);
 566 +               timezonedb_system = tmp;
 567 +       }
 568 +
 569 +       return timezonedb_system;
 570 +#else
 571         return &timezonedb_builtin;
 572 +#endif
 573  }
 574
 575  const timelib_tzdb_index_entry *timelib_timezone_identifiers_list(const timelib_tzdb *tzdb, int *count)
 576 @@ -617,7 +1096,30 @@ const timelib_tzdb_index_entry *timelib_
 577  int timelib_timezone_id_is_valid(const char *timezone, const timelib_tzdb *tzdb)
 578  {
 579         const unsigned char *tzf;
 580 -       return (seek_to_tz_position(&tzf, timezone, tzdb));
 581 +
 582 +#ifdef HAVE_SYSTEM_TZDATA
 583 +       if (tzdb == timezonedb_system) {
 584 +               char fname[PATH_MAX];
 585 +               struct stat st;
 586 +
 587 +               if (timezone[0] == '\0' || strstr(timezone, "..") != NULL) {
 588 +                       return 0;
 589 +               }
 590 +
 591 +               if (system_location_table) {
 592 +                       if (find_zone_info(system_location_table, timezone) != NULL) {
 593 +                               /* found in cache */
 594 +                               return 1;
 595 +                       }
 596 +               }
 597 +
 598 +               snprintf(fname, sizeof fname, ZONEINFO_PREFIX "/%s", canonical_tzname(timezone));
 599 +
 600 +               return stat(fname, &st) == 0 && is_valid_tzfile(&st, 0);
 601 +       }
 602 +#endif
 603 +
 604 +       return (inmem_seek_to_tz_position(&tzf, timezone, tzdb));
 605  }
 606
 607  static int skip_64bit_preamble(const unsigned char **tzf, timelib_tzinfo *tz)
 608 @@ -662,6 +1164,8 @@ static timelib_tzinfo* timelib_tzinfo_ct
 609  timelib_tzinfo *timelib_parse_tzfile(const char *timezone, const timelib_tzdb *tzdb, int *error_code)
 610  {
 611         const unsigned char *tzf;
 612 +       char *memmap = NULL;
 613 +       size_t maplen;
 614         timelib_tzinfo *tmp;
 615         int version;
 616         int transitions_result, types_result;
 617 @@ -669,7 +1173,7 @@ timelib_tzinfo *timelib_parse_tzfile(con
 618
 619         *error_code = TIMELIB_ERROR_NO_ERROR;
 620
 621 -       if (seek_to_tz_position(&tzf, timezone, tzdb)) {
 622 +       if (seek_to_tz_position(&tzf, timezone, &memmap, &maplen, tzdb)) {
 623                 tmp = timelib_tzinfo_ctor(timezone);
 624
 625                 version = read_preamble(&tzf, tmp, &type);
 626 @@ -712,11 +1216,36 @@ timelib_tzinfo *timelib_parse_tzfile(con
 627                         return NULL;
 628                 }
 629
 630 +#ifdef HAVE_SYSTEM_TZDATA
 631 +               if (memmap) {
 632 +                       const struct location_info *li;
 633 +
 634 +                       /* TZif-style - grok the location info from the system database,
 635 +                        * if possible. */
 636 +
 637 +                       if ((li = find_zone_info(system_location_table, timezone)) != NULL) {
 638 +                               tmp->location.comments = timelib_strdup(li->comment);
 639 +                               strncpy(tmp->location.country_code, li->code, 2);
 640 +                               tmp->location.longitude = li->longitude;
 641 +                               tmp->location.latitude = li->latitude;
 642 +                               tmp->bc = 1;
 643 +                       }
 644 +                       else {
 645 +                               set_default_location_and_comments(&tzf, tmp);
 646 +                       }
 647 +
 648 +                       /* Now done with the mmap segment - discard it. */
 649 +                       munmap(memmap, maplen);
 650 +               } else {
 651 +#endif
 652                 if (type == TIMELIB_TZINFO_PHP) {
 653                         read_location(&tzf, tmp);
 654                 } else {
 655                         set_default_location_and_comments(&tzf, tmp);
 656                 }
 657 +#ifdef HAVE_SYSTEM_TZDATA
 658 +               }
 659 +#endif
 660         } else {
 661                 *error_code = TIMELIB_ERROR_NO_SUCH_TIMEZONE;
 662                 tmp = NULL;