TypeError not raised for 'String + nil'

[parzival@…]

This is fairly minor since it's something that ought not to happen, except that both macirb and macruby lock up when it happens.

This works (well, you get the expected error):

"stuff" << nil

TypeError: can't convert nil into String

This does not:

"stuff" + nil

I end up having to kill it.

I've tried it with both 0.3 and the latest testing branch.

[lsansonetti@…]

Fixed in #711/trunk.