[Patch] NPE changing colour on GPX markers layer

[alester]

What steps will reproduce the problem?

1. Open a GPX file containing waypoints
2. Delete the layer named after the GPX file
3. Right-click on the "Markers from..." GPX file layer and select "Customize color"
4. Select a colour and click OK

What is the expected result?

The colour of the markers should be changed

What happens instead?

An exception dialog is displayed. After closing the dialog and changing zoom level, the colour change does take effect.

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

If it makes any difference, the GPX file was created on a Garmin Oregon 700 device.

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2021-06-02 22:03:39 +0200 (Wed, 02 Jun 2021)
Build-Date:2021-06-02 20:11:30
Revision:17919
Relative:URL: ^/trunk

Identification: JOSM/1.5 (17919 en) Windows 10 64-Bit
OS Build number: Windows 10 Pro 2004 (19041)
Memory Usage: 638 MB / 7282 MB (345 MB allocated, but free)
Java version: 1.8.0_291-b10, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1920×1080 (scaling 1.00×1.00) \Display1 1920×1080 (scaling 1.00×1.00)
Maximum Screen Size: 1920×1080
Best cursor sizes: 16×16→32×32, 32×32→32×32
System property file.encoding: Cp1252
System property sun.jnu.encoding: Cp1252
Locale info: en_US
Numbers with default locale: 1234567890 -> 1234567890

Plugins:
+ FixAddresses (35640)
+ ImportImagePlugin (35567)
+ PicLayer (1.0.1)
+ apache-commons (35524)
+ canvec_helper (35458)
+ ejml (35458)
+ geotools (35458)
+ jaxb (35543)
+ jogl (1.2.3)
+ jts (35458)
+ log4j (35458)
+ measurement (35640)
+ opendata (35640)
+ pbf (35720)
+ poly (35640)
+ reltoolbox (35640)
+ reverter (35732)
+ routing (35640)
+ terracer (35640)
+ todo (30306)
+ turnrestrictions (35640)
+ utilsplugin2 (35691)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/OneClick&zip=1

Map paint styles:
+ https://josm.openstreetmap.de/josmfile?page=Styles/Maxspeed&zip=1

Last errors/warnings:
- 00094.907 E: Failed to locate image 'Block, Green'
- 00094.908 E: Failed to locate image 'Flag, Blue'
- 00094.908 E: Failed to locate image 'Block, Green'
- 00094.909 E: Failed to locate image 'Block, Green'
- 00094.910 E: Failed to locate image 'Block, Green'
- 00094.911 E: Failed to locate image 'Block, Green'
- 00094.912 E: Failed to locate image 'Block, Green'
- 00094.914 E: Failed to locate image 'Block, Green'
- 00094.915 E: Failed to locate image 'Block, Green'
- 00100.669 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 (19) of main
java.lang.NullPointerException
	at org.openstreetmap.josm.gui.preferences.display.GPXSettingsPanel.putLayerPrefLocal(GPXSettingsPanel.java:268)
	at org.openstreetmap.josm.gui.preferences.display.GPXSettingsPanel.putLayerPrefLocal(GPXSettingsPanel.java:254)
	at org.openstreetmap.josm.gui.layer.markerlayer.MarkerLayer.setColor(MarkerLayer.java:483)
	at org.openstreetmap.josm.gui.layer.CustomizeColor.lambda$actionPerformed$0(CustomizeColor.java:87)
	at java.util.ArrayList.forEach(Unknown Source)
	at org.openstreetmap.josm.gui.layer.CustomizeColor.actionPerformed(CustomizeColor.java:87)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.AbstractButton.doClick(Unknown Source)
	at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
	at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(Unknown Source)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at javax.swing.JComponent.processMouseEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.dispatchEvent(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)

[Bjoeni]

Could you please upload the original GPX file that caused this issue?

[alester]

I've experienced the issue with any Garmin-generated waypoint file recently. I haven't tested with non-Garmin files. I've uploaded an example.

While testing to confirm just now, I realized that my workflow is a bit different from what I originally listed. I'm normally only interested in the "Markers from..." layer, so I always delete the other layer that's created when I open a GPX file (named after the file). I'm actually not even sure why there are two layers or what this other one is intended to be used for. If I leave this layer in place, I can change the colour of the markers layer successfully with no errors. It's only when I delete the GPX layer that I get the exception when changing the colour of the markers. I'll update the steps to reproduce.

[Bjoeni]

Replying to alester:

It's only when I delete the GPX layer that I get the exception when changing the colour of the markers.

Yes, that's it. Thanks!

(regression of #16796)

[Bjoeni]

src/org/openstreetmap/josm/gui/preferences/display/GPXSettingsPanel.java

@@ -250 +250 @@
      * @param value the value or <code>null</code> to remove key
      */
     public static void putLayerPrefLocal(GpxLayer layer, String key, String value) {
-        if (layer == null) return;
+        if (layer == null || layer.data == null) return;
         putLayerPrefLocal(layer.data, key, value);
     }

[Bjoeni]

See also #20913, the WIP patch there happens to fix this issue as well. But in case that one doesn't make it for 21.06, this one should probably be fixed first.

[Don-vip]

In 17997/josm:

fix #20962 - fix NPE changing colour on GPX markers layer (patch by Bjoeni)

[Don-vip]

Ticket #20772 has been marked as a duplicate of this ticket.