NPE when using piclayer plugin without data layer

[RafalR]

This error occurs when I want to edit a layer:

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2012-05-15 01:31:01
Last Changed Author: simon04
Revision: 5240
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2012-05-14 15:04:43 +0200 (Mon, 14 May 2012)
Last Changed Rev: 5240

Identification: JOSM/1.5 (5240 pl)
Memory Usage: 989 MB / 989 MB (778 MB allocated, but free)
Java version: 1.6.0_31, Sun Microsystems Inc., Java HotSpot(TM) Client VM
Operating system: Windows Vista

Plugin: PicLayer (27883)
Plugin: openstreetbugs (27852)

java.lang.NullPointerException
	at org.openstreetmap.josm.data.UndoRedoHandler.afterAdd(UndoRedoHandler.java:51)
	at org.openstreetmap.josm.data.UndoRedoHandler.add(UndoRedoHandler.java:59)
	at org.openstreetmap.josm.plugins.piclayer.command.TransformCommand.addIfChanged(TransformCommand.java:87)
	at org.openstreetmap.josm.plugins.piclayer.actions.GenericPicTransformAction.mouseReleased(GenericPicTransformAction.java:91)
	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$1.run(Unknown Source)
	at java.awt.EventQueue$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$2.run(Unknown Source)
	at java.awt.EventQueue$2.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$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)

[Larry0ua]

Steps how to reproduce the bug are needed.

Do not see how to reproduce it easily (or that may be introduced in some latest version, and then that is core problem)

[skyper]

Ticket #9936 has been marked as a duplicate of this ticket.

[Don-vip]

In 6994/josm:

fix #7705 - NPE when using piclayer plugin without data layer