Should be fixed in YMenu / YPopupWindow for all menus, but we need it now
for the window menu (to disable it in the installation icewm)
---
 src/wmframe.cc |    2 ++
 1 file changed, 2 insertions(+)

Index: src/wmframe.cc
===================================================================
--- src/wmframe.cc.orig
+++ src/wmframe.cc
@@ -2017,6 +2017,8 @@ void YFrameWindow::popupSystemMenu(YWind
 {
     if (fPopupActive == 0) {
         updateMenu();
+	if (windowMenu()->itemCount() == 0)
+            return;
         if (windowMenu()->popup(owner, forWindow, this,
                                 x, y, flags))
             fPopupActive = windowMenu();