Re: pos-visible-in-window-p at ellipsis

[Chong Yidong]

Richard Stallman <address@hidden> writes:

>     This happens because the pixel position reported by pos_visible_p can
>     overshoot when there is invisible text (see the comment in
>     xdisp.c:1321).  It would be rather complicated to compensate for this
>     (and potentially buggy since pos_visible_p is used by many other
>     functions).
>
> Why is invisible text difficult?  Can't it just skip to the
> next visible character?  (The comment doesn't say what is hard.)

It *does* skip, and that's the problem.  That means that to determine
the actual upper-left pixel position, you need to backtrack to
compensate for the skipping.  That's why invisible text is difficult.