[gtk/gtk-3-24] (2 commits) ...Merge branch 'more-nullable-gtk3' into 'gtk-3-24'

From: Timm Bäder <baedert src gnome org>
To: commits-list gnome org
Cc:
Subject: [gtk/gtk-3-24] (2 commits) ...Merge branch 'more-nullable-gtk3' into 'gtk-3-24'
Date: Mon, 19 Nov 2018 07:40:58 +0000 (UTC)

Summary of changes:

  31b810a... g-i: Add some nullable annotations
  5e78646... Merge branch 'more-nullable-gtk3' into 'gtk-3-24'