bug#18504: 24.3.93; posn-at-point intermittently returns wrong value for a valid buffer position

[Eli Zaretskii]

> Date: Tue, 23 Sep 2014 22:39:49 +0400
> From: Dmitry Gutov <dgutov@yandex.ru>
> CC: 18504-done@debbugs.gnu.org
> 
> On 09/20/2014 11:13 AM, Eli Zaretskii wrote:
> 
> > This happens when posn-at-point is called with the company-mode
> > overlay still (or already?) in place at that position.  That overlay
> > has the invisible property, so it hides the buffer text starting at
> > the position with which you call posn-at-point.  Therefore,
> > posn-at-point returns information about the first visible buffer
> > position after the overlay string.
> 
> I see, thanks. But does the fact that we get a different return value 
> with different values of bidi-display-reordering, look right to you?

You are not supposed to change the value of bidi-display-reordering.
This variable exists only for debugging.  So what happens when it is
nil is "undefined behavior" ;-)