NPE at mapillary.data.image.Detections.getDetections

[GhostFoxSledgehammer]

What steps will reproduce the problem?

1. I'm not sure what triggered this but I Restarted a failed download and this happened after sometime.

What is the expected result?

What happens instead?

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

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-12-28 22:03:23 +0100 (Mon, 28 Dec 2020)
Revision:17428
Build-Date:2020-12-29 02:30:53
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (17428 en) Windows 10 64-Bit
OS Build number: Windows 10 Home Single Language 2004 (19041)
Memory Usage: 1610 MB / 2048 MB (721 MB allocated, but free)
Java version: 15.0.1+9-18, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1920×1080 (scaling 1.25×1.25)
Maximum Screen Size: 1920×1080
Best cursor sizes: 16×16→32×32, 32×32→32×32
Dataset consistency test: No problems found

Plugins:
+ Mapillary (1.5.33-dirty)
+ apache-commons (35524)
+ apache-http (35589)
+ imagery_offset_db (35640)
+ jna (35662)
+ turnrestrictions (35640)

Last errors/warnings:
- 00687.770 W: Server timeout, trying https://a.mapillary.com/v3/image_detections?client_id=UTZhSnNFdGpxSEFFREUwb01GYzlXZzpjNGViMzQxMTIzMjY0MjZm&bbox=2.3415899%2C48.8505265%2C2.3666096%2C48.8612987&layers=trafficsigns&sort_by=key again (attempt 2 of 2)
- 00687.771 W: java.io.IOException: javax.json.JsonException: I/O error while auto-detecting the encoding of stream. Cause: javax.json.JsonException: I/O error while auto-detecting the encoding of stream. Cause: java.io.IOException: stream is closed
- 00687.936 W: java.io.IOException: javax.json.JsonException: I/O error while auto-detecting the encoding of stream. Cause: javax.json.JsonException: I/O error while auto-detecting the encoding of stream. Cause: java.io.IOException: stream is closed
- 00691.546 W: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out
- 00691.547 E: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out
- 00691.577 W: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out
- 00691.623 W: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out
- 00691.623 W: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out
- 00691.624 E: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out
- 00692.165 E: Handled by bug report queue: java.lang.NullPointerException: Cannot invoke "org.openstreetmap.josm.plugins.mapillary.data.image.Detections.getDetections(boolean)" because "image" is null



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

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: ForkJoinPool.commonPool-worker-13 (36)
java.lang.NullPointerException: Cannot invoke "org.openstreetmap.josm.plugins.mapillary.data.image.Detections.getDetections(boolean)" because "image" is null
	at org.openstreetmap.josm.plugins.mapillary.gui.MapillaryMainDialog.updateDetections(MapillaryMainDialog.java:515)
	at org.openstreetmap.josm.plugins.mapillary.gui.MapillaryMainDialog.lambda$updateImage$1(MapillaryMainDialog.java:485)
	at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1429)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1016)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1665)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1598)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:183)

[taylor.smock]

This is probably due to a race condition. Sometime between the start of updateImage and when detections are updated, the image stored changes. This is probably the same base cause as ​Github #165.

I've made some modifications so that race conditions should be much rarer in that section of code.

This should be fixed (hopefully) in ​e9cc9bf5039916592c96099f38cb91b9d88b62de.

[taylor.smock]

I didn't see any other critical bugs, so I made a new release with this fix: ​v1.5.34.

[GhostFoxSledgehammer]

Replying to taylor.smock:

This is probably due to a race condition. Sometime between the start of updateImage and when detections are updated, the image stored changes.

I remember double-clicking empty space but didn't think that could have caused the NPE. Also I got the same error multiple times simultaneously. Hopefully it will be fixed with v.1.5.34.