Re: x-popup-menu pops up at funny positions

[Richard Stallman]

    Because it did not in fact read the current position.  It read
    the position of the inner window in coordinates that are valid
    for the parent window.  Now, if the parent window is the root
    window, then it reads the current position.  But in all other
    cases it does not.

Instead of just deleting that code, can you replace it with code
that does the right job?

    One could replace parent_desc with the root window, but it
    seemd pointless to do a query to the X server when Emacs
    has all the information already and a simple addition finds
    the current position.

I am not sure it is always up to date.  Could you check?

    Replacing mouse_position_hook with a simple XQueryPointer
    cures this.

Could you send the diff to do that?
(Or just install it?)