[gnome-games] display-view: Don't set visible-child for null runner

[Alexander Mikhaylenko <alexm src gnome org>]

commit 0ff082b59a703554d6eb1c01cf667167b462ffd7
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Mon Jun 8 22:46:41 2020 +0500

    display-view: Don't set visible-child for null runner
    
    We're supposed to show an error, and yet we immediately show the (empty)
    display widget.

 src/ui/display-view.vala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/ui/display-view.vala b/src/ui/display-view.vala
index 55671913..f63c8548 100644
--- a/src/ui/display-view.vala
+++ b/src/ui/display-view.vala
@@ -74,14 +74,14 @@ private class Games.DisplayView : Gtk.Box, UiView {
                        if (runner != null)
                                runner.snapshot_created.disconnect (flash_box.flash);
 
-                       stack.visible_child = display_overlay;
-
                        _runner = value;
                        remove_display ();
 
                        if (runner == null)
                                return;
 
+                       stack.visible_child = display_overlay;
+
                        var display = runner.get_display ();
                        set_display (display);
 
@@ -580,7 +580,7 @@ private class Games.DisplayView : Gtk.Box, UiView {
                can_fullscreen = false;
                runner = null;
                media_button.media_set = null;
-               secondary_menu_button.visible = null;
+               secondary_menu_button.visible = false;
 
                update_actions ();
        }