bug#21469: 25.0.50; right scrollbar wrongly placed when resizing split window

[martin rudalics]

>>From a console or from an xterm? From an xterm I get nothing output at
> all.

My memory probably fails.  Somewhere GTK should write a log maybe I find
out where.

Thanks for the pngs.  Please do the following:

(1) After starting, evaluate the form (window--dump-frame).  This should
    produce a buffer called *window-frame-dump*.  Post the contents
    here.

(2) Now split the single window via C-x 3, evaluate (window--dump-frame)
    again and post the new contents of the *window-frame-dump* buffer.
    And please also post a png of the frame at that time.

(3) Now drag the border, evaluate (window--dump-frame) once more, post
    the new *window-frame-dump* buffer contents and a png of the frame.

Hopefully we can deduce something from these.

Thanks, martin