NPE while trying to exit JOSM

[AndrewSnow]

What steps will reproduce the problem?

1. Open JOSM, download data, upload changes
2. Attempt to exit

What is the expected result?

Exiting JOSM

What happens instead?

Error dialog box. Need to use Windows Task Manager to force a shutdown.

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: 2016-07-11 23:04:49 +0200 (Mon, 11 Jul 2016)
Build-Date:2016-07-12 01:31:48
Revision:10526
Relative:URL: ^/trunk

Identification: JOSM/1.5 (10526 en) Windows 7 64-Bit
Memory Usage: 560 MB / 989 MB (218 MB allocated, but free)
Java version: 1.8.0_101-b13, Oracle Corporation, Java HotSpot(TM) Client VM
Dataset consistency test: No problems found

Plugins:
- DirectDownload (32442)
- FastDraw (32639)
- FixAddresses (32445)
- HouseNumberTaggingTool (32584)
- ImproveOsm (73)
- Mapillary (32639)
- OpeningHoursEditor (32583)
- SimplifyArea (32517)
- apache-commons (32584)
- apache-http (32584)
- areaselector (271)
- buildings_tools (32639)
- colorscheme (32584)
- download_along (32535)
- editgpx (32485)
- ejml (32639)
- ext_tools (32309)
- geotools (32584)
- gson (32639)
- jts (32539)
- log4j (32309)
- mapdust (32473)
- measurement (32454)
- merge-overlap (32471)
- opendata (32584)
- plastic_laf (32309)
- public_transport (32639)
- reltoolbox (32639)
- routes (32456)
- scoutsigns (79)
- turnrestrictions (32629)
- utilsplugin2 (32584)
- walkingpapers (32476)
- waydownloader (32584)
- wikipedia (32671)

Tagging presets:
- <josm.pref>\MyPresets.xml
- http://somewhere.dk/email/josm/source.xml
- https://josm.openstreetmap.de/josmfile?page=Presets/BicycleJunction&preset&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/Camp_site_extends&preset&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/Communication_Towers&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/Crafts&preset&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/Historical_Objects&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/MountainbikeTrails&preset&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/Mountains&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/NewParkingFeatures&preset&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/NewTags&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/OneClick&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/Playground_Equipment&preset&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/PublicTransportOneClick&preset&zip=1
- https://josm.openstreetmap.de/josmfile?page=Presets/Quick-highways&zip=1

Map paint styles:
- https://github.com/hotosm/HDM-JOSM-style/archive/master.zip
- https://josm.openstreetmap.de/josmfile?page=Styles/AddressValidator&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/BesideTheRoad_Speed&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Cycleways&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Fixme&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Highway_Nodes&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Lane_features&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Lane_features_ryg&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/LessObtrusiveNodes&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/MTB&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Maxspeed&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Modified&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Mountains&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/NewParkingFeatures&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Noname&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/NumberedCycleNodeNetworks&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Osmc&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/ParkingLanes&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Potlach2_access&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/SimpleRoofTags&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/SlovakiaBicycleRoutes&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Surface-DataEntry&style&zip=1

Last errors/warnings:
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: Old style SideButton usage for action org.openstreetmap.josm.gui.conflict.tags.CombinePrimitiveResolverDialog$ApplyAction@2124e8
- W: Old style SideButton usage for action org.openstreetmap.josm.gui.conflict.tags.CombinePrimitiveResolverDialog$CancelAction@6568b1
- W: Old style SideButton usage for action org.openstreetmap.josm.gui.help.ContextSensitiveHelpAction@16d198f
- E: java.lang.NullPointerException

java.lang.NullPointerException
	at org.openstreetmap.josm.tools.ImageResource.getImageIcon(ImageResource.java:203)
	at org.openstreetmap.josm.tools.ImageProvider.get(ImageProvider.java:649)
	at org.openstreetmap.josm.gui.io.SaveLayersDialog$SaveAndProceedAction.<init>(SaveLayersDialog.java:386)
	at org.openstreetmap.josm.gui.io.SaveLayersDialog.<init>(SaveLayersDialog.java:72)
	at org.openstreetmap.josm.Main.saveUnsavedModifications(Main.java:1116)
	at org.openstreetmap.josm.Main.saveUnsavedModifications(Main.java:1103)
	at org.openstreetmap.josm.Main.exitJosm(Main.java:1157)
	at org.openstreetmap.josm.gui.MainFrame$3.windowClosing(MainFrame.java:105)
	at java.awt.AWTEventMulticaster.windowClosing(Unknown Source)
	at java.awt.Window.processWindowEvent(Unknown Source)
	at javax.swing.JFrame.processWindowEvent(Unknown Source)
	at java.awt.Window.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(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$3.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.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)

[Don-vip]

In 10642/josm:

fix #13184 - NPE while trying to exit JOSM