Description:
------------
ZTS build of PHP uses getgrnam_r, getgrgid_r, getpwnam_r and getpwuid_r
behind their respective posix_* functions. These functions may return ERANGE
if the buffer supplied by the caller is too small.
sysconf() returns 1024 for _SC_GETGR_R_SIZE_MAX and _SC_GETPW_R_SIZE_MAX.
Only posix_getgrnam calling getgrnam_r handles ERANGE properly by
retrying with a larger buffer.
This was noticed on a system with a group containing many users, so
the respective line in /etc/group exceeded 2KB.

Test script:
---------------
<?php
  $i = 200; /* a GID that has a very long line in /etc/group */
  $data = posix_getgrgid($i);
  $error_num = posix_get_last_error();
  if ($error_num > 0) {
    echo "\nERROR NUM = $error_num\n";
    echo "ERROR MES = " . posix_strerror($error_num) . "\n\n";
  } else {
    printf("%s\n", $data["name"]);
  }
?>


Expected result:
----------------
The group name should be printed.

Actual result:
--------------
Error number 34 (ERANGE) is printed.