Comment 2 for bug 488279

Create work -> Petri net -> Add cycle (p1-t1-p2-t2-) -> group {p1, t1} -> move the group -> Exception

Here is the stack trace:

Exception in thread "AWT-EventQueue-0" Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
 at org.workcraft.dom.visual.connections.Polyline.componentsTransformChanged(Polyline.java:351)
 at org.workcraft.dom.visual.connections.ComponentsTransformObserver.notify(ComponentsTransformObserver.java:88)
 at org.workcraft.dom.visual.TransformEventPropagator.propagate(TransformEventPropagator.java:132)
 at org.workcraft.dom.visual.TransformEventPropagator.propagate(TransformEventPropagator.java:135)
 at org.workcraft.dom.visual.TransformEventPropagator.notify(TransformEventPropagator.java:141)
 at org.workcraft.observation.ObservableStateImpl.sendNotification(ObservableStateImpl.java:39)
 at org.workcraft.dom.visual.VisualNode.sendNotification(VisualNode.java:160)
 at org.workcraft.dom.visual.VisualTransformableNode.transformChanged(VisualTransformableNode.java:98)
 at org.workcraft.dom.visual.VisualTransformableNode.applyTransform(VisualTransformableNode.java:144)
 at org.workcraft.dom.visual.MovableHelper.translate(MovableHelper.java:31)
 at org.workcraft.gui.graph.tools.SelectionTool.offsetSelection(SelectionTool.java:423)
 at org.workcraft.gui.graph.tools.SelectionTool.mouseMoved(SelectionTool.java:191)
 at org.workcraft.gui.graph.GraphEditorPanelMouseListener.mouseMoved(GraphEditorPanelMouseListener.java:60)
 at org.workcraft.gui.graph.GraphEditorPanelMouseListener.mouseDragged(GraphEditorPanelMouseListener.java:48)
 at java.awt.Component.processMouseMotionEvent(Unknown Source)
 at javax.swing.JComponent.processMouseMotionEvent(Unknown Source)
 at java.awt.Component.processEvent(Unknown Source)
 at java.awt.Container.processEvent(Unknown Source)
 at java.awt.Component.dispatchEventImpl(Unknown Source)
 at java.awt.Container.dispatchEventImpl(Unknown Source)
 at java.awt.Component.dispatchEvent(Unknown Source)
 at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
 at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
 at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
 at java.awt.Container.dispatchEventImpl(Unknown Source)
 at java.awt.Window.dispatchEventImpl(Unknown Source)
 at java.awt.Component.dispatchEvent(Unknown Source)
 at java.awt.EventQueue.dispatchEvent(Unknown Source)
 at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
 at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
 at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
 at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
 at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
 at java.awt.EventDispatchThread.run(Unknown Source)