JOSM throws an exception after a decent amount of no interaction, and switching back to the desktop that had JOSM running

[anonymous]

What steps will reproduce the problem?

1. Start JOSM
2. Edit and Upload
3. Wait some time (hours?), leave it running on some workspace
4. Switch back to workspace

What is the expected result?

No crash

What happens instead?

Crash

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

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2016-05-02 10:23:17 +0200 (Mon, 02 May 2016)
Build-Date:2016-05-03 01:31:45
Revision:10168
Relative:URL: ^/trunk

Identification: JOSM/1.5 (10168 en_GB) Linux Debian GNU/Linux unstable (sid)
Memory Usage: 569 MB / 1744 MB (149 MB allocated, but free)
Java version: 1.8.0_91-8u91-b14-2-b14, Oracle Corporation, OpenJDK 64-Bit Server VM
VM arguments: [-Djava.net.preferIPv4Stack=true]
Dataset consistency test: No problems found

Plugins:
- HouseNumberTaggingTool (31772)
- OpeningHoursEditor (31772)
- PicLayer (32158)
- buildings_tools (31895)
- conflation (0.1.9)
- continuosDownload (1446070193)
- download_along (31772)
- ext_tools (31772)
- jts (31772)
- measurement (31895)
- merge-overlap (31967)
- public_transport (31895)
- reltoolbox (31895)
- reverter (32005)
- terracer (31895)
- turnrestrictions (31895)
- utilsplugin2 (32099)

Last errors/warnings:
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- E: java.lang.ClassCastException: sun.awt.image.BufImgSurfaceData cannot be cast to sun.java2d.xr.XRSurfaceData
- E: java.lang.ClassCastException: sun.awt.image.BufImgSurfaceData cannot be cast to sun.java2d.xr.XRSurfaceData
- E: java.lang.ClassCastException: sun.awt.image.BufImgSurfaceData cannot be cast to sun.java2d.xr.XRSurfaceData

java.lang.ClassCastException: sun.awt.image.BufImgSurfaceData cannot be cast to sun.java2d.xr.XRSurfaceData
	at sun.java2d.xr.XRPMBlitLoops.cacheToTmpSurface(XRPMBlitLoops.java:145)
	at sun.java2d.xr.XrSwToPMBlit.Blit(XRPMBlitLoops.java:353)
	at sun.java2d.pipe.DrawImage.blitSurfaceData(DrawImage.java:959)
	at sun.java2d.pipe.DrawImage.renderImageCopy(DrawImage.java:577)
	at sun.java2d.pipe.DrawImage.copyImage(DrawImage.java:67)
	at sun.java2d.pipe.DrawImage.copyImage(DrawImage.java:1014)
	at sun.java2d.pipe.ValidatePipe.copyImage(ValidatePipe.java:186)
	at sun.java2d.SunGraphics2D.drawImage(SunGraphics2D.java:3318)
	at sun.java2d.SunGraphics2D.drawImage(SunGraphics2D.java:3296)
	at org.openstreetmap.josm.gui.MapView.paint(MapView.java:834)
	at javax.swing.JComponent.paintChildren(JComponent.java:889)
	at javax.swing.JComponent.paint(JComponent.java:1065)
	at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210)
	at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:290)
	at javax.swing.RepaintManager.paint(RepaintManager.java:1272)
	at javax.swing.JComponent._paintImmediately(JComponent.java:5158)
	at javax.swing.JComponent.paintImmediately(JComponent.java:4969)
	at javax.swing.RepaintManager$4.run(RepaintManager.java:831)
	at javax.swing.RepaintManager$4.run(RepaintManager.java:814)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
	at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814)
	at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789)
	at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738)
	at javax.swing.RepaintManager.access$1200(RepaintManager.java:64)
	at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
	at org.GNOME.Accessibility.AtkWrapper$5.dispatchEvent(AtkWrapper.java:697)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

[Don-vip]

Closed as duplicate of #11002.