> With Emacs 25.2 under MacOS 10.12, I use a mouse key that has bindings on
> both its depress and release states. The depress is in a frame with 2
> windows (one showing *Buffer List* and the other showing hmouse-drv.el).
> The depress occurs in the *Buffer List* window.
>
> The release occurs in another frame and the release window is showing
> hui-window.el.
Are the frames occupying separate areas on your screen or do they
intersect?
> Here is the drag event generated. Element 2 shows the proper depress
> window but element 3 shows the depress frame rather than the release
> frame. And element 3 has a frame rather than a window as its first
> argument even though the Elisp manual says it should be a window.
IIRC it's a frame when there's no suitable window at the specified
position. This is largely undocumented and has been sometimes even used
wrongly in the Emacs code base itself.
> (drag-mouse-2 (#<window 90 on *Buffer List*> 2905 (88 . 467) 4050744642 nil
> 2905 (12 . 33) nil (4 . 5) (7 . 14)) (#<frame hmouse-drv.el
> "/Users/bk/Dropbox/emacs/hyperbole/" 0x102f5bde8> nil (-1373 . 463) The start event seems to look OK. As for the end event, an X-coordinate
> 4050749802))
of -1373 does not look reasonable.
Please post results for dragging from
one to another window on the same frame.