NPE when querying for history of deleted node

[malenki]

What steps will reproduce the problem?

1. undelete an object – it doesn't matter if with undelete or reverter plugin (example: node 2173268750)
2. select it
3. press ctrl-h

What is the expected result?

history window with versions pops up

What happens instead?

The NPE you see below. Additionally, JOSM then seems to be in a very unstable condition. Alt-F4 then closes layer after layer. Creating new layers and dragging around a deleted object results in additional NPEs

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

Tested with JOSM latest on a blank ~/.josm with plugins reverter and undelete.
r9436 is fine, r9460 shows the error

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2016-01-16 03:00:56 +0100 (Sat, 16 Jan 2016)
Build-Date:2016-01-16 02:34:12
Revision:9480
Relative:URL: ^/trunk

Identification: JOSM/1.5 (9480 de) Linux Debian GNU/Linux unstable (sid)
Memory Usage: 552 MB / 2222 MB (256 MB allocated, but free)
Java version: 1.8.0_72-internal-b05, Oracle Corporation, OpenJDK 64-Bit Server VM
VM arguments: [-Dsun.java2d.opengl=false]
Dataset consistency test: No problems found

Plugins:
- undelete (31895)

Last errors/warnings:
- E: java.lang.NullPointerException
- E: java.lang.reflect.InvocationTargetException. Ursache: java.lang.NullPointerException
- E: java.lang.NullPointerException

java.lang.NullPointerException
	at org.openstreetmap.josm.gui.history.CoordinateInfoViewer$MapViewer.update(CoordinateInfoViewer.java:341)
	at java.util.Observable.notifyObservers(Observable.java:159)
	at java.util.Observable.notifyObservers(Observable.java:115)
	at org.openstreetmap.josm.gui.history.HistoryBrowserModel.fireModelChange(HistoryBrowserModel.java:198)
	at org.openstreetmap.josm.gui.history.HistoryBrowserModel.setLatest(HistoryBrowserModel.java:640)
	at org.openstreetmap.josm.gui.history.HistoryBrowserModel.setHistory(HistoryBrowserModel.java:188)
	at org.openstreetmap.josm.gui.history.HistoryBrowser.populate(HistoryBrowser.java:127)
	at org.openstreetmap.josm.gui.history.HistoryBrowserDialog.setHistory(HistoryBrowserDialog.java:130)
	at org.openstreetmap.josm.gui.history.HistoryBrowserDialog.<init>(HistoryBrowserDialog.java:115)
	at org.openstreetmap.josm.gui.history.HistoryBrowserDialogManager.show(HistoryBrowserDialogManager.java:146)
	at org.openstreetmap.josm.gui.history.HistoryBrowserDialogManager$1$1.run(HistoryBrowserDialogManager.java:205)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)