Description:
------------
In Mac OS X 10.8 mountain lion, getpwnam() && getgrnam() didn't return NULL
when empty string supplied. this is a bug of 10.8.0

since uid 0 an gid 0 most belongs to root, this might have security issue.

and this breaks these test cases:
posix_getgrnam(): Basic tests [ext/posix/tests/posix_getgrnam.phpt]
posix_getgrnam(): Basic tests [ext/posix/tests/posix_getgrnam_basic.phpt]
posix_getpwnam(): Basic tests [ext/posix/tests/posix_getpwnam.phpt]
posix_getpwnam(): Basic tests [ext/posix/tests/posix_getpwnam_basic.phpt]

here is reproducible code from: Andreas Fink <afink@list.fink.org>:
#include <sys/types.h>
#include <stdio.h>
#include <pwd.h>
#include <uuid/uuid.h>
#include <stdlib.h>

#define	MAYBE_NULL_STRING(a)	(a ? a : "(NULL)")

extern int errno;

int main(int argc, char *argv[])
{
	errno = 0;
	struct passwd *pwdstruct = getpwnam("");
	printf("errno = %d\n",errno);
	if(pwdstruct == NULL)
	{
		printf("pwdstruct == NULL\n");
		exit(0);
	}

	printf("pw_name: %s\n",MAYBE_NULL_STRING(pwdstruct->pw_name));
	printf("pw_passwd: %s\n",MAYBE_NULL_STRING(pwdstruct->pw_passwd));
	printf("pw_uid: %d\n",pwdstruct->pw_uid);
	printf("pw_gid: %d\n",pwdstruct->pw_gid);
}


produces

$ ./a.out 
errno = 0
pw_name: 
pw_passwd: 
pw_uid: 0
pw_gid: 0


Test script:
---------------
<?php
var_dump(posix_getpwnam(""));
var_dump(posix_getgrnam(""));

Expected result:
----------------
bool(false)
bool(false)

Actual result:
--------------
array(7) {
  ["name"]=>
  string(0) ""
  ["passwd"]=>
  string(0) ""
  ["uid"]=>
  int(0)
  ["gid"]=>
  int(0)
  ["gecos"]=>
  string(0) ""
  ["dir"]=>
  string(0) ""
  ["shell"]=>
  string(0) ""
}
array(4) {
  ["name"]=>
  string(0) ""
  ["passwd"]=>
  string(0) ""
  ["members"]=>
  array(0) {
  }
  ["gid"]=>
  int(0)
}