Bug 297570 - Crash in nsMenuFrame when the menu is display: none (seen in "GM" extension), regression from bug 295711 - use visibility: collapse as a workaround for the time being r=mconnor sr=bz

toolkit/content/xul.css

@@ -274,7 +274,7 @@ menu.menu-iconic {
 }
 
 menu:empty {
-  display: none;
+  visibility: collapse;
 }
 
 /********* menuitem ***********/

xpfe/global/resources/content/xul.css

@@ -243,7 +243,7 @@ menu.menu-iconic {
 }
 
 menu:empty {
-  display: none;
+  visibility: collapse;
 }
 
 /********* menuitem ***********/