Fix for clarification menu crash (GAL/Windows).

common/tool/context_menu.cpp

@@ -227,17 +227,14 @@ void CONTEXT_MENU::onMenuEvent( wxMenuEvent& aEvent )
                 wxMenu* menu = NULL;
                 FindItem( m_selected, &menu );
 
-                if( menu )
+                if( menu && menu != this )
                 {
                     menu->ProcessEvent( aEvent );
                     return;
                 }
-
-                assert( false );    // The event should be handled above
             }
-#else
+#endif
             evt = m_customHandler( aEvent );
-#endif /* else __WINDOWS__ */
 
             // Handling non-action menu entries (e.g. items in clarification list)
             if( !evt )