Re: ptrdiff_t misuse [was :Re: (empty)]

[Stefan Monnier]

> Argh, I misuse them against window_end_pos and window_end_bytepos,
> which are positions in a buffer and so ptrdiff_t :-(.  This should
> be reverted.

Not only there: hscroll and min_hscroll should be `int' fields.
And similarly Paul's "fix" to use:

  ptrdiff_t clipped_arg
    = clip_to_bounds (- w->hscroll, requested_arg, HSCROLL_MAX - w->hscroll);

should be reverted.  Really, 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.

Properly catching/handling integer overflows is a good idea, but C makes
it much too painful in general, so we don't want to do it in
unrealistic corner cases, preferring code cleanliness.



        Stefan