tracer + testing josm = error dialog

[ukulele]

What steps will reproduce the problem?

1. turn on wms layer
2. use tracer plugin
3. sometimes it show this error

What is the expected result?
tracer should do it's work with no error

What happens instead?
it makes what i want, but shows the error dialog

Please provide any additional information below. Attach a screenshot if
possible.

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2010-04-23 01:31:33
Last Changed Author: bastiK
Revision: 3199
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2010-04-22 23:39:51 +0200 (Thu, 22 Apr 2010)
Last Changed Rev: 3199

Memory Usage: 1016 MB / 1323 MB (365 MB allocated, but free)
Java version: 1.6.0_16, Sun Microsystems Inc., Java HotSpot(TM) Client VM
Operating system: Linux

Dataset consistency test:
No problems found


Plugins: DirectUpload,Tracer,buildings_tools,routes,terracer,walkingpapers,waydownloader,wmsplugin
Plugin walkingpapers (Version: 19487)
Plugin wmsplugin (Version: 20566)
Plugin routes (Version: 20427)
Plugin buildings_tools (Version: 20269)
Plugin DirectUpload (Version: 19700)
Plugin waydownloader (Version: 19489)
Plugin terracer (Version: 20084)
Plugin Tracer (Version: 20251)

java.util.ConcurrentModificationException
	at org.openstreetmap.josm.data.osm.Storage$Iter.align(Storage.java:413)
	at org.openstreetmap.josm.data.osm.Storage$Iter.hasNext(Storage.java:394)
	at org.openstreetmap.josm.data.osm.DatasetCollection$FilterIterator.findNext(DatasetCollection.java:23)
	at org.openstreetmap.josm.data.osm.DatasetCollection$FilterIterator.hasNext(DatasetCollection.java:33)
	at org.openstreetmap.josm.actions.search.SearchAction.getSelection(SearchAction.java:287)
	at org.openstreetmap.josm.data.osm.Filters.executeFilters(Filters.java:53)
	at org.openstreetmap.josm.gui.dialogs.FilterDialog.processDatasetEvent(FilterDialog.java:193)
	at org.openstreetmap.josm.data.osm.event.DataSetListenerAdapter.primtivesAdded(DataSetListenerAdapter.java:31)
	at org.openstreetmap.josm.data.osm.event.PrimitivesAddedEvent.fire(PrimitivesAddedEvent.java:25)
	at org.openstreetmap.josm.data.osm.event.DatasetEventManager.fireConsolidatedEvents(DatasetEventManager.java:117)
	at org.openstreetmap.josm.data.osm.event.DatasetEventManager.access$300(DatasetEventManager.java:27)
	at org.openstreetmap.josm.data.osm.event.DatasetEventManager$1.run(DatasetEventManager.java:187)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:178)
	at java.awt.Dialog$1.run(Dialog.java:1045)
	at java.awt.Dialog$3.run(Dialog.java:1097)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.awt.Dialog.show(Dialog.java:1095)
	at java.awt.Component.show(Component.java:1563)
	at java.awt.Component.setVisible(Component.java:1515)
	at java.awt.Window.setVisible(Window.java:841)
	at java.awt.Dialog.setVisible(Dialog.java:985)
	at org.openstreetmap.josm.gui.progress.PleaseWaitProgressMonitor$3.run(PleaseWaitProgressMonitor.java:83)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

[bastiK]

Closed as duplicate of #4861.