bug#31695:

[martin rudalics <rudalics@gmx.at>]

 > The window-point jumps unexpectedly after minibuffer interaction when a
 > buffer is being displayed in two frames, and the frames do not have
 > their own minibuffers.
 >
 > To reproduce: emacs -Q -D and create two frames displaying some buffer
 > at different points
 >
 > (with-selected-frame (setq $a (make-frame '((minibuffer))))
 >    (let ((enable-local-variables :all))
 >      (view-emacs-news)
 >      (beginning-of-buffer)))
 >
 > (with-selected-frame (setq $b (make-frame '((minibuffer))))
 >    (let ((enable-local-variables :all))
 >      (view-emacs-news)
 >      (end-of-buffer)))
 >
 > Now select frame $b, and execute some minibuffer command:
 > M-: 1
 >
 > The point in the window of frame $b, which was at the bottom now jumps
 > to the top of the buffer.  (This corresponds with the point in the
 > buffer in the other frame where it is displayed.

This works correctly here in Emacs 23.4.1 and is broken in 24.5.50.1.
If Eli doesn't come up with a clue, could someone with a fast machine
please try to bisect this.

Thanks in advance, martin