On 06/29/2012 12:07 PM, Stefan Monnier wrote:
> if someone ever bumps into a problem
> because of such an overflow, I'll be*super*  happy, because it means
> that all the performance problems we get with long lines have
> been fixed.

No, if the overflow happens to generate a small integer,
Emacs will run quickly and incorrectly
without the patch in question.  Perhaps
there's a better fix, and certainly that area
of the code needs changing if hscroll
is changed to 'int' as suggested; but some fix
is needed.