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

[Dmitry Gutov <dgutov@yandex.ru>]

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?

> So I think you need to make sure inside company--col-row that the
> overlay is popped down, before you call posn-at-point.  Evidently, in
> some scenarios it isn't.

Yes, seems to be a bug with the way we set the "current" keymap when 
completion is performed (the popup is displayed only during that time). 
Thank you for confirming, I'm looking into it.

> The buffer position returned by
> posn-at-point can serve as your control variable: if it is different
> from the position that is the argument to company--col-row, you have
> this situation.

Ok. I can just directly check if the overlay has the `invisible' 
property set to t or not, though. We keep a reference to the overlay.