bug#28621: Proposed patch for doc of posn-window and code of posn-set-point to handle frame arguments

[Eli Zaretskii]

> Date: Fri, 29 Sep 2017 10:34:44 +0200
> From: martin rudalics <rudalics@gmx.at>
> 
>  > ! `posn-window': The window or frame of the event end.
> 
> If we start talking about "event ends" here we should export that
> concept to the remaining ‘posn-*’ functions as well.

Agreed.

>  > ! If POSITION is outside the frame where the event was initiated, return
>  > ! that frame instead.  POSITION should be a list of the form returned by
> 
> I suppose this is not sufficient: We get a frame also when the mouse is
> on its tool or menu bar, some of ist borders ...

Right.  Btw, the manual has this problem as well.

> But note that I've never been able to understand the purpose of these
> ‘posn-*’ functions and they usually confuse the hell out of me.  IMHO it
> would make much more sense to declare them obsolete and concentrate on
> describing event structures better.

We should do both, IMO.