NPE while loading JOSM (related with IPv6 it seems)

[naoliv]

I saw this while loading JOSM:

2017-07-24 09:34:51.103 GRAVE: java.util.concurrent.ExecutionException: java.lang.NullPointerException. Causa: java.lang.NullPointerException
java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(FutureTask.java:122)
	at java.util.concurrent.FutureTask.get(FutureTask.java:192)
	at org.openstreetmap.josm.gui.util.GuiHelper.runInEDTAndWaitAndReturn(GuiHelper.java:172)
	at org.openstreetmap.josm.Main.exitJosm(Main.java:836)
	at org.openstreetmap.josm.actions.RestartAction.restartJOSM(RestartAction.java:87)
	at org.openstreetmap.josm.gui.MainApplication.lambda$checkIPv6$5(MainApplication.java:501)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
	at org.openstreetmap.josm.Main.addMapFrameListener(Main.java:1172)
	at org.openstreetmap.josm.actions.SessionSaveAsAction.<init>(SessionSaveAsAction.java:75)
	at org.openstreetmap.josm.gui.io.SaveLayersDialog$SaveSessionAction.<init>(SaveLayersDialog.java:438)
	at org.openstreetmap.josm.gui.io.SaveLayersDialog.<init>(SaveLayersDialog.java:93)
	at org.openstreetmap.josm.gui.io.SaveLayersDialog.saveUnsavedModifications(SaveLayersDialog.java:111)
	at org.openstreetmap.josm.Main.lambda$exitJosm$7(Main.java:837)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	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:80)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
	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:9

It seems that it didn't affect anything in JOSM, but I am not sure.

JOSM:

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2017-07-23 23:59:49 +0200 (Sun, 23 Jul 2017)
Build-Date:2017-07-24 01:31:50
Revision:12504
Relative:URL: ^/trunk

Identification: JOSM/1.5 (12504 pt_BR) Linux Debian GNU/Linux testing (buster)
Memory Usage: 247 MB / 10206 MB (90 MB allocated, but free)
Java version: 1.8.0_131-8u131-b11-2-b11, Oracle Corporation, OpenJDK 64-Bit Server VM
Screen: :0.0 1600x900, :0.1 1280x1024
Maximum Screen Size: 1600x1024
Java package: openjdk-8-jre:amd64-8u131-b11-2
Java ATK Wrapper package: libatk-wrapper-java:all-0.33.3-13
VM arguments: [-Dawt.useSystemAAFontSettings=on]

Plugins:
+ Create_grid_of_ways (32699)
+ FastDraw (33182)
+ ImportImagePlugin (33372)
+ OpeningHoursEditor (33185)
+ PicLayer (33385)
+ RoadSigns (33204)
+ SimplifyArea (33004)
+ apache-commons (32994)
+ buildings_tools (33004)
+ conflation (0.5.4)
+ contourmerge (1030)
+ download_along (32946)
+ editgpx (33004)
+ ejml (32680)
+ geojson (52)
+ geotools (33380)
+ importvec (33088)
+ indoorhelper (33088)
+ jts (32699)
+ log4j (32699)
+ measurement (33088)
+ merge-overlap (33436)
+ opendata (33438)
+ pbf (33241)
+ pdfimport (33004)
+ poly (33004)
+ reverter (33088)
+ scripting (30768)
+ tageditor (33021)
+ todo (30200)
+ turnlanes (33294)
+ turnlanes-tagging (254)
+ turnrestrictions (33088)
+ undelete (33374)
+ utilsplugin2 (33328)

[Don-vip]

why do you think it's related to ipv6? It seems unrelated.

[naoliv]

Wild guess is because it happened after testing the IPv6 connectivity.
It seems that it didn't detect a good IPv6 connection, tried to restart (but somehow failed) and kept loading JOSM.
At least reading this seems to match what I could see:

	at org.openstreetmap.josm.Main.exitJosm(Main.java:836)
	at org.openstreetmap.josm.actions.RestartAction.restartJOSM(RestartAction.java:87)
	at org.openstreetmap.josm.gui.MainApplication.lambda$checkIPv6$5(MainApplication.java:501)

[stoecker]

Replying to naoliv:

Wild guess is because it happened after testing the IPv6 connectivity.
It seems that it didn't detect a good IPv6 connection, tried to restart (but somehow failed) and kept loading JOSM.
At least reading this seems to match what I could see:

	at org.openstreetmap.josm.Main.exitJosm(Main.java:836)
	at org.openstreetmap.josm.actions.RestartAction.restartJOSM(RestartAction.java:87)
	at org.openstreetmap.josm.gui.MainApplication.lambda$checkIPv6$5(MainApplication.java:501)

In this case it is probably Restart-related. Does this also happen when you cause a restart of JOSM any other way?

[naoliv]

Replying to stoecker:

In this case it is probably Restart-related. Does this also happen when you cause a restart of JOSM any other way?

I don't know.
When I ask to restart it doesn't output anything else to console.
I need to see if there is a way to take a look at the messages after restarting.

[bastiK]

The NPE seems plausible as Main.mainPanel is not yet initialized when checkIPv6() is called.

[Don-vip]

In 12507/josm:

fix #15062 - avoid NPE when restarting JOSM