William,

 > If I may be permitted to make a remark from the sidelines:
 > 
 > > I don't like this solution since it would still trigger save stack
 > > overflow when there is an unclosed group at the end of the document.
 > >
 > > I quite prefer the usual warning about an open group at the end of
 > > document over having a save stack capacity overflow triggered.
 > 
 > Unclosed groups are likely obstacles for translation of LaTeX to
 > formats like the usual tex4ht targets.

I don't think that David meant that an unclosed group should be ignored, but
that it is better to to get "document ended while group xyz open" than to bomb
with a stack overflow (for the same reason but harder to understand).

frank