NullPointerException when filtering undirected graphs

[Mathieu Bastian]

Way to reproduce:
1) Open a graph file, undirected
2) Create "Degree Range Filter" and enable filtering
3) Play with range slide
An exception is thrown sometimes, with higher probability is layout is active

Stack Trace:
java.lang.NullPointerException
 at org.gephi.graph.dhns.edge.AbstractEdge.getUndirected(AbstractEdge.java:92)
 at org.gephi.graph.dhns.edge.iterators.EdgeIterator.hasNext(EdgeIterator.java:59)
 at org.gephi.graph.dhns.graph.iterators.EdgeIteratorImpl.hasNext(EdgeIteratorImpl.java:44)
 at org.gephi.visualization.bridge.DHNSDataBridge.updateEdges(DHNSDataBridge.java:187)
 at org.gephi.visualization.bridge.DHNSDataBridge.updateWorld(DHNSDataBridge.java:126)
 at org.gephi.visualization.opengl.compatibility.CompatibilityEngine.updateWorld(CompatibilityEngine.java:181)
 at org.gephi.visualization.opengl.compatibility.CompatibilityScheduler.updateWorld(CompatibilityScheduler.java:270)

[Michael (fireang3l)]

I get the same symptoms in alpha 4 - here's the stack trace, which is different than from the original report

java.lang.NullPointerException
 at org.gephi.visualization.opengl.compatibility.objects.Edge2dModel.isInOctreeLeaf(Edge2dModel.java:112)
 at org.gephi.visualization.opengl.octree.Octree.updateObjectsPosition(Octree.java:268)
 at org.gephi.visualization.opengl.compatibility.CompatibilityEngine.updateObjectsPosition(CompatibilityEngine.java:636)
 at org.gephi.visualization.opengl.compatibility.CompatibilityScheduler.updatePosition(CompatibilityScheduler.java:279)
[catch] at org.gephi.visualization.scheduler.SimpleFPSAnimator.run(SimpleFPSAnimator.java:58)