new WMS entry caused crash of JOSM

[razor88]

What steps will reproduce the problem?

What is the expected result?

What happens instead?

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

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2011-09-05 01:31:49
Last Changed Author: bastiK
Revision: 4399
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2011-09-04 22:13:51 +0200 (Sun, 04 Sep 2011)
Last Changed Rev: 4399

Identification: JOSM/1.5 (4399 de)
Memory Usage: 57 MB / 494 MB (10 MB allocated, but free)
Java version: 1.6.0_27, Sun Microsystems Inc., Java HotSpot(TM) Client VM
Operating system: Windows 7

Plugin: AddrInterpolation (26606)
Plugin: FixAddresses (26606)
Plugin: OpeningHoursEditor (26606)
Plugin: PicLayer (26606)
Plugin: buildings_tools (26606)
Plugin: dataimport (26606)
Plugin: globalsat (26606)
Plugin: imageryadjust (26606)
Plugin: irsrectify (26605)
Plugin: lakewalker (26606)
Plugin: licensechange (26606)
Plugin: multipoly-convert (26606)
Plugin: openstreetbugs (26606)
Plugin: restart (26606)
Plugin: terracer (26606)
Plugin: turnlanes (26702)
Plugin: turnrestrictions (26606)

java.lang.NullPointerException
	at org.openstreetmap.josm.gui.preferences.AddWMSLayerPanel.commaSepLayerList(AddWMSLayerPanel.java:283)
	at org.openstreetmap.josm.gui.preferences.AddWMSLayerPanel.buildGetMapUrl(AddWMSLayerPanel.java:274)
	at org.openstreetmap.josm.gui.preferences.AddWMSLayerPanel.access$800(AddWMSLayerPanel.java:68)
	at org.openstreetmap.josm.gui.preferences.AddWMSLayerPanel$6.stateChanged(AddWMSLayerPanel.java:228)
	at javax.swing.JTabbedPane.fireStateChanged(Unknown Source)
	at javax.swing.JTabbedPane