Description:
------------
 As the description says, there is wrong check in mysqli, which doesn't allow the mysqlnd code to run. mysqli returns always 0 for num_rows() even if the whole result set has been read. This bug exists since 5.3.0, which first bundled mysqli with mysqlnd.

Test script:
---------------
./php -r '$c=mysqli_connect("127.0.0.1","root","root","test");var_dump($c->real_query("SELECT 1"));var_dump($res=$c->use_result(), mysqli_num_rows($res), $res->fetch_assoc(), mysqli_num_rows($res), $res->fetch_assoc(), mysqli_num_rows($res));'

Expected result:
----------------
Warning: mysqli_num_rows(): Function cannot be used with MYSQL_USE_RESULT in Command line code on line 1

Warning: mysqli_num_rows(): Function cannot be used with MYSQL_USE_RESULT in Command line code on line 1
object(mysqli_result)#2 (5) {
  ["current_field"]=>
  int(0)
  ["field_count"]=>
  int(1)
  ["lengths"]=>
  array(1) {
    [0]=>
    int(1)
  }
  ["num_rows"]=>
  int(1)
  ["type"]=>
  int(0)
}
int(0)
array(1) {
  [1]=>
  string(1) "1"
}
int(0)
NULL
int(1)  ----- here is the difference

Actual result:
--------------
Warning: mysqli_num_rows(): Function cannot be used with MYSQL_USE_RESULT in Command line code on line 1

Warning: mysqli_num_rows(): Function cannot be used with MYSQL_USE_RESULT in Command line code on line 1
object(mysqli_result)#2 (5) {
  ["current_field"]=>
  int(0)
  ["field_count"]=>
  int(1)
  ["lengths"]=>
  array(1) {
    [0]=>
    int(1)
  }
  ["num_rows"]=>
  int(1)
  ["type"]=>
  int(0)
}
int(0)
array(1) {
  [1]=>
  string(1) "1"
}
int(0)
NULL
int(0) --- should have been 1