On upgrade from Emacs 24.3.1 to Emacs 25.0.50 pasting unicode from external applications with mouse wheel appears broken.
emacs -Q and select e.g. title of https://en.wikipedia.org/wiki/Paul_Erdős wikipedia entry in firefox. However with mouse wheel I get
where as with normal
clipboard-yank works fine:
Pasting the same with mouse wheel (aka
<mouse-2>) from Emacs selection works fine.