Validate menu items for their object's existence

Fixes #2778

diff --git a/wcfsetup/install/files/lib/data/menu/item/MenuItem.class.php b/wcfsetup/install/files/lib/data/menu/item/MenuItem.class.php
index 2c4d0078ca6b0b201ca048fdc04742a9fe1a259f..0a35cbf12b5249e10a1efd5625506f6b17c470b9 100644 (file)
--- a/wcfsetup/install/files/lib/data/menu/item/MenuItem.class.php
+++ b/wcfsetup/install/files/lib/data/menu/item/MenuItem.class.php
@@ -118,7 +118,12 @@ class MenuItem extends DatabaseObject {
                }
                
                if ($this->getMenuPageHandler() !== null) {
-                       return $this->getMenuPageHandler()->isVisible($this->pageObjectID ?: null);
+                       $menuPageHandler = $this->getMenuPageHandler();
+                       if ($menuPageHandler instanceof ILookupPageHandler && !$menuPageHandler->isValid($this->pageObjectID ?: null)) {
+                               return false;
+                       }
+                       
+                       return $menuPageHandler->isVisible($this->pageObjectID ?: null);
                }
                
                return true;