This bug was fixed in the package gtk+3.0 - 3.22.30-1ubuntu3
---
gtk+3.0 (3.22.30-1ubuntu3) bionic; urgency=medium
[ Sebastien Bacher ]
* d/p/Check-for-NULL-priv-popup_window-in-gtk_combo_box_popdown.patch:
- Check for NULL priv->popup_window in gtk_combo_box_popdown()
(lp
Looking upstream it seems similar to
https://gitlab.gnome.org/GNOME/gtk/issues/125 , the warning is indeed
fixed in the current Ubuntu serie, could be a candidate to include if we
do a SRU update for gtk but doesn't seem an high importance one/probably
not worth an update by itself
** Package cha
