Description:
------------
It seems that isset (likely others like unset, empty, etc) cannot properly resolve variably-named variables and simply returns true.

Test script:
---------------
function testWrapper()
{
	foreach (array(
		'testvar1',
		'testvar2'
	) AS $varname)
	{
		if (!isset($$varname))
		{
			echo "\nSetting $varname\n";
			$$varname = array();
		}

		var_dump($$varname);
	}
}

testWrapper();

Expected result:
----------------
Setting testvar1
array(0) {}
Setting testvar2
array(0) {}

Actual result:
--------------
NULL
NULL