undoing multipolygon changes causes exception

[ij]

1. Create a closed way
2. Put that to a type=multipolygon relation
3. Connect a way (a tail) to one of the middle nodes of the loop (pointing towards it)
4. Combine those two, you need to agree reversing.
5. Extend the tail
6. Undoing the changes fires an exception

[bastiK]

confirmed with 4666

[Don-vip]

OK I got it too:

java.lang.NullPointerException
	at org.openstreetmap.josm.data.osm.visitor.paint.relations.Multipolygon$PolyData.resetNodes(Multipolygon.java:285)
	at org.openstreetmap.josm.data.osm.visitor.paint.relations.Multipolygon$PolyData.wayNodesChanged(Multipolygon.java:328)
	at org.openstreetmap.josm.data.osm.visitor.paint.relations.MultipolygonCache.dispatchEvent(MultipolygonCache.java:181)
	at org.openstreetmap.josm.data.osm.visitor.paint.relations.MultipolygonCache.processEvent(MultipolygonCache.java:162)
	at org.openstreetmap.josm.data.osm.visitor.paint.relations.MultipolygonCache.updateMultipolygonsReferringTo(MultipolygonCache.java:149)
	at org.openstreetmap.josm.data.osm.visitor.paint.relations.MultipolygonCache.updateMultipolygonsReferringTo(MultipolygonCache.java:128)
	at org.openstreetmap.josm.data.osm.visitor.paint.relations.MultipolygonCache.updateMultipolygonsReferringTo(MultipolygonCache.java:123)
	at org.openstreetmap.josm.data.osm.visitor.paint.relations.MultipolygonCache.wayNodesChanged(MultipolygonCache.java:216)
	at org.openstreetmap.josm.data.osm.event.WayNodesChangedEvent.fire(WayNodesChangedEvent.java:22)
	at org.openstreetmap.josm.data.osm.DataSet.fireEventToListeners(DataSet.java:1022)
	at org.openstreetmap.josm.data.osm.DataSet.endUpdate(DataSet.java:1001)
	at org.openstreetmap.josm.data.UndoRedoHandler.undo(UndoRedoHandler.java:88)
	at org.openstreetmap.josm.data.UndoRedoHandler.undo(UndoRedoHandler.java:66)
	at org.openstreetmap.josm.actions.UndoAction.actionPerformed(UndoAction.java:34)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
	at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
	at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at javax.swing.JComponent.processMouseEvent(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.dispatchEventImpl(Unknown Source)
	at java.awt.EventQueue.access$000(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(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)

[Don-vip]

In [4667/josm]:

fix #7162 - undoing multipolygon changes causes exception (NPE)