Sorting relation with stop_exit_only role

[maarten]

Since JOSM 8800, sorting a relation that has a member stop_exit_only role in it results in an error message. The error is copied below.
I have made a test relation for this: relation 5652897

Revision: 8969
Repository Root: http://josm.openstreetmap.de/svn
Relative URL: ^/trunk
Last Changed Author: Don-vip
Last Changed Date: 2015-10-29 22:15:23 +0100 (Thu, 29 Oct 2015)
Build-Date: 2015-10-30 02:32:24
URL: http://josm.openstreetmap.de/svn/trunk
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last Changed Rev: 8969

Identification: JOSM/1.5 (8969 en) Windows 7 64-Bit
Memory Usage: 165 MB / 1160 MB (78 MB allocated, but free)
Java version: 1.8.0_40, Oracle Corporation, Java HotSpot(TM) Client VM
Dataset consistency test: No problems found

Plugins:
- HouseNumberTaggingTool (31603)
- apache-commons (31718)
- download_along (31603)
- ext_tools (31603)
- geotools (31603)
- jts (31603)
- log4j (31603)
- measurement (31694)
- photo_geotagging (31694)
- public_transport (31646)
- reverter (31694)
- routing (31694)
- terracer (31694)
- undelete (31603)
- utilsplugin2 (31694)
- wms-turbo-challenge2 (31603)

Last errors/warnings:
- E: java.lang.AssertionError
- E: java.lang.AssertionError
- E: java.lang.AssertionError
- E: java.lang.AssertionError
- E: java.lang.AssertionError

java.lang.AssertionError
	at org.openstreetmap.josm.gui.dialogs.relation.MemberTableModel.sort(MemberTableModel.java:703)
	at org.openstreetmap.josm.gui.dialogs.relation.GenericRelationEditor$SortAction.actionPerformed(GenericRelationEditor.java:1077)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$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.dispatchEventImpl(Unknown Source)
	at java.awt.EventQueue.access$500(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$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)

[simon04]

Likely a regression of r8517.

[simon04]

In 8998/josm:

fix #12082 - Sorting relation with stop_exit_only role