More 1.7 BC issues (porting from 1.5)

Hi, I have this use case which involves 2 nested macros and a foreach.
I am trying to understand why this template evaluates to empty string
on 1.7, and to "foobaryokdar" - on 1.5.


String template = "#set($global_types=['foo', 'bar', 'yok',
'dar'])#macro( showBox $input)#set($type = \"\")$input#end"+
                "#macro(showBoxes $types)#foreach($type in
$types)#showBox($type)#end#end#showBoxes($global_types)";