On Tue, Apr 29, 2008 at 11:43:44AM +0100, John Thornborrow wrote:
> >I always use ifNotNilDo: (or ifNil:ifNotNilDo: or variant) if I need to 
> >use a block with one argument. ifNotNil: sends valueWithPossibleArgs: so 
> >you don't have to send a block with an argument.
> >
> and just to add, when I try and use a one-arg block and try to 'do' it, 
> I am told: " <- argument of ifNotNil: must be a 0-argument block ->"

This bug is documented on Mantis at http://bugs.squeak.org/view.php?id=4867

Dave