guard against use of setParent

svn path=/trunk/KDE/kdelibs/; revision=1014484

containmentactions.cpp

@@ -133,7 +133,7 @@ PackageStructure::Ptr ContainmentActions::packageStructure()
 
 Containment *ContainmentActions::containment()
 {
-    return static_cast<Containment*>(parent());
+    return qobject_cast<Containment*>(parent());
 }
 
 QString ContainmentActions::name() const
@@ -299,6 +299,17 @@ void ContainmentActions::paste(QPointF scenePos, QPoint screenPos)
     }
 }
 
+bool ContainmentActions::event(QEvent *e)
+{
+    if (e->type() == QEvent::ParentChange) {
+        if (!containment()) {
+            //some fool took away our containment. run away, run away!
+            deleteLater();
+        }
+    }
+    return false;
+}
+
 } // Plasma namespace
 
 #include "containmentactions.moc"

containmentactions.h

@@ -206,6 +206,8 @@ class PLASMA_EXPORT ContainmentActions : public QObject
          */
         static QString eventToString(QEvent *event);
 
+        bool event(QEvent *e);
+
     protected:
         /**
          * This constructor is to be used with the plugin loading systems