MapCSS: PatternSyntaxException in case of an (possible) incorrect regular expression

[imagic]

I try to write a rule in a MapCSS style that does NOT match a regular expression. I tried the following rule:

node[traffic_sign~=maxspeed][maxspeed=implicit][overtaking=yes]["source:maxspeed"=~/?!.*zone.*/]

This resulted in a PatternSyntaxException (see below). The regular expression might be wrong (actually I don't know) but it should not crash JOSM.

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2013-04-09 01:34:26
Last Changed Author: stoecker
Revision: 5836
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2013-04-07 23:18:22 +0200 (Sun, 07 Apr 2013)
Last Changed Rev: 5836

Identification: JOSM/1.5 (5836 en) Linux
Memory Usage: 306 MB / 853 MB (89 MB allocated, but free)
Java version: 1.6.0_20, Sun Microsystems Inc., Java HotSpot(TM) Server VM
Operating system: Linux
VM arguments: [-DproxySet=xxxx, -DproxyHost=xxxxx, -DproxyPort=xxxx]
Dataset consistency test: No problems found

Plugin: buildings_tools (29435)
Plugin: imagery_offset_db (29467)
Plugin: openstreetbugs (29435)
Plugin: openvisible (29435)
Plugin: reverter (29435)
Plugin: turnrestrictions (29435)
Plugin: utilsplugin2 (29435)

java.util.regex.PatternSyntaxException: Dangling meta character '?' near index 0
?!.*zone.*
^
	at java.util.regex.Pattern.error(Pattern.java:1713)
	at java.util.regex.Pattern.sequence(Pattern.java:1878)
	at java.util.regex.Pattern.expr(Pattern.java:1752)
	at java.util.regex.Pattern.compile(Pattern.java:1460)
	at java.util.regex.Pattern.<init>(Pattern.java:1133)
	at java.util.regex.Pattern.compile(Pattern.java:823)
	at org.openstreetmap.josm.gui.mappaint.mapcss.Condition$Op.eval(Condition.java:77)
	at org.openstreetmap.josm.gui.mappaint.mapcss.Condition$KeyValueCondition.applies(Condition.java:161)
	at org.openstreetmap.josm.gui.mappaint.mapcss.Selector$GeneralSelector.matchesConditions(Selector.java:286)
	at org.openstreetmap.josm.gui.mappaint.mapcss.Selector$GeneralSelector.matches(Selector.java:295)
	at org.openstreetmap.josm.gui.mappaint.mapcss.MapCSSStyleSource.apply(MapCSSStyleSource.java:157)
	at org.openstreetmap.josm.gui.mappaint.ElemStyles.generateStyles(ElemStyles.java:303)
	at org.openstreetmap.josm.gui.mappaint.ElemStyles.getImpl(ElemStyles.java:151)
	at org.openstreetmap.josm.gui.mappaint.ElemStyles.getStyleCacheWithRange(ElemStyles.java:71)
	at org.openstreetmap.josm.gui.mappaint.ElemStyles.get(ElemStyles.java:54)
	at org.openstreetmap.josm.data.osm.visitor.paint.StyledMapRenderer$StyleCollector.add(StyledMapRenderer.java:182)
	at org.openstreetmap.josm.data.osm.visitor.paint.StyledMapRenderer.collectNodeStyles(StyledMapRenderer.java:360)
	at org.openstreetmap.josm.data.osm.visitor.paint.StyledMapRenderer.render(StyledMapRenderer.java:1390)
	at org.openstreetmap.josm.gui.layer.OsmDataLayer.paint(OsmDataLayer.java:317)
	at org.openstreetmap.josm.gui.MapView.paintLayer(MapView.java:503)
	at org.openstreetmap.josm.gui.MapView.paint(MapView.java:587)
	at javax.swing.JComponent.paintChildren(JComponent.java:862)
	at javax.swing.JComponent.paint(JComponent.java:1038)
	at javax.swing.JComponent.paintChildren(JComponent.java:862)
	at javax.swing.JSplitPane.paintChildren(JSplitPane.java:1030)
	at javax.swing.JComponent.paint(JComponent.java:1038)
	at javax.swing.JComponent.paintChildren(JComponent.java:862)
	at javax.swing.JComponent.paint(JComponent.java:1038)
	at javax.swing.JComponent.paintChildren(JComponent.java:862)
	at javax.swing.JComponent.paint(JComponent.java:1038)
	at javax.swing.JComponent.paintChildren(JComponent.java:862)
	at javax.swing.JComponent.paint(JComponent.java:1038)
	at javax.swing.JComponent.paintChildren(JComponent.java:862)
	at javax.swing.JComponent.paint(JComponent.java:1038)
	at javax.swing.JLayeredPane.paint(JLayeredPane.java:567)
	at javax.swing.JComponent.paintChildren(JComponent.java:862)
	at javax.swing.JComponent.paint(JComponent.java:1038)
	at javax.swing.JComponent.paintToOffscreen(JComponent.java:5124)
	at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:278)
	at javax.swing.RepaintManager.paint(RepaintManager.java:1224)
	at javax.swing.JComponent._paintImmediately(JComponent.java:5072)
	at javax.swing.JComponent.paintImmediately(JComponent.java:4882)
	at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:785)
	at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:713)
	at javax.swing.RepaintManager.seqPaintDirtyRegions(RepaintManager.java:693)
	at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueUtilities.java:125)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)