Description: Avoid segfault if xscreensaver-gl-visual is not installed
Forwarded: not-needed
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1030659
Author: Tormod Volden <debian.tormod@gmail.com>

Index: xscreensaver-git/driver/demo-Gtk.c
===================================================================
--- xscreensaver-git.orig/driver/demo-Gtk.c
+++ xscreensaver-git/driver/demo-Gtk.c
@@ -3291,7 +3291,9 @@ fix_preview_visual (state *s)
   GdkWindow *gwindow = gtk_widget_get_window (GTK_WIDGET (win));
   GdkScreen *gscreen = gdk_window_get_screen (gwindow);
   GdkVisual *gvisual1 = gdk_screen_get_system_visual (gscreen);
-  GdkVisual *gvisual2 = x_visual_to_gdk_visual (gwindow, xvisual);
+  GdkVisual *gvisual2 = (xvisual
+                         ? x_visual_to_gdk_visual (gwindow, xvisual)
+                         : 0);
 
   if (! gvisual2)
     {