Description:
------------
$a = 'aa';
$b = 'bb';
$value = 0;
switch ($value) {
	case $a:
		echo $a."\n"; 
		break;
	case $b:
		echo $b."\n"; 
		break;
	default:	
		echo "default\n";
}
==> output: aa (Why?!)

$a = 'aa';
$b = 'bb';
$value = 0;
switch ($value) {
	case $b:
		echo $b."\n"; 
		break;
	case $a:
		echo $a."\n"; 
		break;
	default:	
		echo "default\n";
}
==> output: bb (Why?!)


Reproduce code:
---------------
$a = 'aa';
$b = 'bb';
$value = 0;
switch ($value) {
	case $a:
		echo $a."\n"; 
		break;
	case $b:
		echo $b."\n"; 
		break;
	default:	
		echo "default\n";
}


Expected result:
----------------
default

Actual result:
--------------
aa