fixes bug 241036 "need to call gdk_error_trap_push before calling gdk_error_trap_pop [was: Minimo arm-linux build crashes on startup]" r=caillon sr=bryner

gfx/src/gtk/nsScreenGtk.cpp

@@ -137,6 +137,8 @@ nsScreenGtk :: Init ()
   GdkAtom cardinal_atom = (GdkAtom) XA_CARDINAL;
 #endif
 
+  gdk_error_trap_push();
+
   if (!gdk_property_get(root_window,
                         gdk_atom_intern ("_NET_WORKAREA", FALSE),
                         cardinal_atom,
@@ -150,6 +152,9 @@ nsScreenGtk :: Init ()
     return;
   }
 
+  // Flush the X queue to catch errors now.
+  gdk_flush();
+
   if (!gdk_error_trap_pop() &&
       type_returned == cardinal_atom &&
       length_returned && (length_returned % 4) == 0 &&