NPE at org.openstreetmap.josm.actions.DownloadAlongWayAction.createTask with locked=true in osm header

[skyper]

What steps will reproduce the problem?

1. Have a osm data file with locked='true' loaded. See "locked" file​.
2. Select an object
3. Download along

What is the expected result?

The Download Along Dialog opens with disabled download button

What happens instead?

NPE at org.openstreetmap.josm.actions.DownloadAlongWayAction.createTask

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

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-02-03 22:02:21 +0100 (Mon, 03 Feb 2020)
Revision:15813
Build-Date:2020-02-04 02:30:59
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (15813 en) Linux Debian GNU/Linux 10 (buster)
Memory Usage: 193 MB / 500 MB (45 MB allocated, but free)
Java version: 11.0.6+10-post-Debian-1deb10u1, Debian, OpenJDK 64-Bit Server VM
Screen: :0.0 1366x768
Maximum Screen Size: 1366x768
Java package: openjdk-11-jre:amd64-11.0.6+10-1~deb10u1
Java ATK Wrapper package: libatk-wrapper-java:all-0.33.3-22
libcommons-compress-java: libcommons-compress-java:all-1.18-2
libcommons-logging-java: libcommons-logging-java:all-1.2-2
fonts-noto: fonts-noto:all-20181227-1
VM arguments: [-Djosm.home=<josm.pref>]
Dataset consistency test: No problems found

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.
- W: Region [TMS_BLOCK_v2] Resetting cache
- W: Region [WMS_BLOCK_v2] Resetting cache
- W: Region [WMTS_BLOCK_v2] Resetting cache
- W: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out
- E: Handled by bug report queue: java.lang.NullPointerException


=== REPORTED CRASH DATA ===
BugReportExceptionHandler#handleException:
No data collected.

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: AWT-EventQueue-0 (18) of main
java.lang.NullPointerException
	at org.openstreetmap.josm.actions.DownloadAlongWayAction.createTask(DownloadAlongWayAction.java:45)
	at org.openstreetmap.josm.actions.DownloadAlongAction.actionPerformed(DownloadAlongAction.java:303)
	at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
	at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
	at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
	at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
	at java.desktop/javax.swing.AbstractButton.doClick(AbstractButton.java:369)
	at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1020)
	at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1064)
	at java.desktop/java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:297)
	at java.desktop/java.awt.Component.processMouseEvent(Component.java:6632)
	at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
	at java.desktop/java.awt.Component.processEvent(Component.java:6397)
	at java.desktop/java.awt.Container.processEvent(Container.java:2263)
	at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5008)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4840)
	at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4918)
	at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4547)
	at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4488)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307)
	at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2772)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4840)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

[Don-vip]

In 15823/josm:

fix #18678 - fix DownloadAlong with locked layers