Don't crash on close from window manager.

diff --git a/controls/menu.c b/controls/menu.c
index 7026954..0b89690 100644
--- a/controls/menu.c
+++ b/controls/menu.c
@@ -2766,6 +2766,8 @@
     while (!fEndMenu)
     {
 	menu = MENU_GetMenu( mt.hCurrentMenu );
+	if (!menu) /* sometimes happens if I do a window manager close */
+	    break;
 	msg.hwnd = (wFlags & TPM_ENTERIDLEEX && menu->wFlags & MF_POPUP) ? menu->hWnd : 0;
 
 	/* we have to keep the message in the queue until it's