[gnome-control-center/rhel/8.4.0: 13/32] sharing: Fix warning when disabling sharing

[Ray Strode <halfline src gnome org>]

commit 5ecf400fae42707c37ca77541e71e8b8a2cb1e37
Author: Robert Ancell <robert ancell canonical com>
Date:   Mon Oct 15 11:49:19 2018 +1300

    sharing: Fix warning when disabling sharing
    
    The warning is:
    (gnome-control-center:29760): Gtk-CRITICAL **: 11:45:48.076: gtk_widget_is_visible: assertion 
'GTK_IS_WIDGET (widget)' failed
    
    This is due to the code trying to disable switches that only exist if support
    for that feature is available.

 panels/sharing/cc-sharing-panel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/panels/sharing/cc-sharing-panel.c b/panels/sharing/cc-sharing-panel.c
index adcbcdc86..ab22f5df8 100644
--- a/panels/sharing/cc-sharing-panel.c
+++ b/panels/sharing/cc-sharing-panel.c
@@ -99,7 +99,7 @@ struct _CcSharingPanelPrivate
   guint remote_desktop_name_watch;
 };
 
-#define OFF_IF_VISIBLE(x) { if (gtk_widget_is_visible(x) && gtk_widget_is_sensitive(x)) 
gtk_switch_set_active (GTK_SWITCH(x), FALSE); }
+#define OFF_IF_VISIBLE(x) { if ((x) != NULL && gtk_widget_is_visible(x) && gtk_widget_is_sensitive(x)) 
gtk_switch_set_active (GTK_SWITCH(x), FALSE); }
 
 static void
 cc_sharing_panel_master_switch_notify (GtkSwitch      *gtkswitch,