Bug#832077: emacs clutter screen on windows switch

[Leon Meier]

found 832077 emacs/46.1
thanks

The message

(emacs:6144): Gtk-WARNING **: GtkWindow 0xc50270 is drawn without a 
current allocation. This should not happen.

is printed to xterm from where emacs was started. Printing happens  when 
the emacs window gets the focus due to a left-button mouse click.

For me, it's not a huge trouble, but still, annoying.