Description:
------------
Qualifying a variable with the keyword global has a tricky but undocumented effect -- it doesn't merely allow code in a function to access global variable, but it actually creates global variables. This should be clearly described in the manual.

Reproduce code:
---------------
function main() {
  global $num;	
  $num = 10;
  test();
}

function test()
{
  $number = $GLOBALS['num'];
  echo "num = $number";
}

Expected result:
----------------
num = 

because $num isn't declared outside all functions

Actual result:
--------------
num = 10