bug#11768: trunk uses deprecated gtk3 functions

[Chong Yidong]

Jan Djärv <jan.h.d@swipnet.se> writes:

>> When I build trunk bzr 108707 on Ubuntu 12.04 x86
>> I get the following diagnostics.  I'm not familiar
>> with gtk3, but can someone who is familiar look into it?
>> Thanks.
>
> Fixed.

This commit (r108881) breaks mouse clicks when Emacs is compiled with
gtk3.  Emacs doesn't seem to register the mouse events at all.

Reopening the bug.