According to the GTK+ bugzilla ticket you created (https://bugzilla.gnome.org/show_bug.cgi?id=775808), the bug was found and a patch made, and went ahead and merged into gtk+ 3.22.x stream on Dec 24, 2016. I think there's been at least one release since then (GTK+ 3.22.7), so it might be worth trying to upgrade again.
According to the GTK+ bugzilla ticket you created (https:/ /bugzilla. gnome.org/ show_bug. cgi?id= 775808), the bug was found and a patch made, and went ahead and merged into gtk+ 3.22.x stream on Dec 24, 2016. I think there's been at least one release since then (GTK+ 3.22.7), so it might be worth trying to upgrade again.