NPE on last layer delete

[Ldp]

• Create a new layer
• Delete the layer
• Try to delete the 'Validation errors' layer

When first removing the validator layer, and then the normal layer, same thing. Create a few new layers, delete them, again an NPE on the last layer delete.

Build-Date: 2009-12-18 09:07:58		
Revision: 2652
Is-Local-Build: true

Memory Usage: 15 MB / 1016 MB (1 MB allocated, but free)
Java version: 1.6.0_17

Dataset consistency test:
No problems found


Plugins: AddrInterpolation,multipoly,terracer,validator,wmsplugin
Plugin AddrInterpolation Version: 18874
Plugin multipoly Version: 18962
Plugin terracer Version: 19129
Plugin validator Version: 19072
Plugin wmsplugin Version: 18953

java.lang.NullPointerException
	at org.openstreetmap.josm.gui.MapView.setActiveLayer(MapView.java:626)
	at org.openstreetmap.josm.gui.MapView.removeLayer(MapView.java:344)
	at org.openstreetmap.josm.Main.removeLayer(Main.java:188)
	at org.openstreetmap.josm.gui.dialogs.LayerListDialog$DeleteLayerAction.actionPerformed(LayerListDialog.java:312)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$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.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.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)

[jttt]

(In [2653]) Fixed #4198 NPE on last layer delete