bug#19988: 25.0.50; Drag events ending in different frame

[martin rudalics]

> When I select a region by dragging Mouse-1 starting at the "selected."
> above, as soon as the mouse cursor leaves the emacs frame, the region
> won't grow or shrink anymore until I enter the frame and window again.
> And when I release the drag outside of the frame and window where I
> started, the final region is the last one before leaving the
> frame/window.

With emacs -Q?  That's very strange.  I've never seen such behavior
anywhere, neither with Emacs nor with any other application I use.

> That's pretty much what I'd expect except that releasing
> the drag outside of the start frame/window inactivates the region.

But how can you possibly mouse-extend the region if your mouse cursor
has to stay within the window?

martin