Freeze upon deleting and re-opening Mapillary imagery layer

[Traaker_L]

What steps will reproduce the problem?

1. Open the Mapillary imagery layer from the Mapillary plugin.
2. Do some editing.
3. Delete the Mapillary imagery layer.
4. Re load the Mapillary imagery layer.

What is the expected result?

The Mapillary layer appears in the editor

What happens instead?

The editor freezes completely after the "Downloading Mapillary images --- Select mode" message appears in the bottom-left corner. The Mapillary Images layer appears in the Layers list, but no images appear in the layer itself.

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

Closing the Mapillary Imagery panel completely seems to prevent the crash. The crash still occurs if the Mapillary Image window is collapsed and present in the side bar with the other panels and not closed completely.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-02-01 01:10:57 +0100 (Sat, 01 Feb 2020)
Revision:15806
Build-Date:2020-02-01 00:12:46
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (15806 en) Mac OS X 10.14.6
OS Build number: Mac OS X 10.14.6 (18G103)
Memory Usage: 1167 MB / 2048 MB (308 MB allocated, but free)
Java version: 11.0.5+10-LTS, Azul Systems, Inc., OpenJDK 64-Bit Server VM
Screen: Display 188945226 1920x1080, Display 69955240 2048x1152
Maximum Screen Size: 2048x1152
VM arguments: [--add-reads=java.base=ALL-UNNAMED,java.desktop, --add-reads=java.desktop=ALL-UNNAMED,java.naming, --add-reads=java.naming=ALL-UNNAMED,java.desktop, --add-exports=java.desktop/sun.awt=ALL-UNNAMED,java.desktop, --add-exports=java.desktop/javax.jnlp=ALL-UNNAMED,java.desktop, --add-exports=java.base/com.sun.net.ssl.internal.ssl=ALL-UNNAMED,java.desktop, --add-exports=java.base/sun.net.www.protocol.jar=ALL-UNNAMED,java.desktop, --add-exports=java.base/sun.security.action=ALL-UNNAMED,java.desktop, --add-exports=java.base/sun.security.provider=ALL-UNNAMED,java.desktop, --add-exports=java.base/sun.security.util=ALL-UNNAMED,java.desktop, --add-exports=java.base/sun.security.validator=ALL-UNNAMED,java.desktop, --add-exports=java.base/sun.security.x509=ALL-UNNAMED,java.desktop, --add-exports=java.base/jdk.internal.util.jar=ALL-UNNAMED,java.desktop, --add-exports=java.base/sun.net.www.protocol.http=ALL-UNNAMED,java.desktop, --add-exports=java.desktop/sun.awt.X11=ALL-UNNAMED,java.desktop, --add-exports=java.desktop/sun.applet=ALL-UNNAMED,java.desktop, --add-exports=java.desktop/sun.applet=ALL-UNNAMED,jdk.jsobject, --add-exports=java.naming/com.sun.jndi.toolkit.url=ALL-UNNAMED,java.desktop]
Dataset consistency test: No problems found

Plugins:
+ EasyPresets (1537621333)
+ Mapillary (1.5.20)
+ apache-commons (35092)
+ apache-http (35092)
+ auto_tools (73)
+ buildings_tools (35248)
+ graphview (35313)
+ intersection (0.0.7)
+ jna (35092)
+ osm-obj-info (56)
+ rex (53)
+ turnrestrictions (35313)
+ utilsplugin2 (35248)

Tagging presets:
+ https://raw.githubusercontent.com/osmlab/name-suggestion-index/master/dist/name-suggestions.presets.xml

Map paint styles:
+ https://raw.githubusercontent.com/KaartGroup/Kaart-Styles/master/Kaart-Styles.mapcss
+ https://raw.githubusercontent.com/KaartGroup/Kaart-Styles/master/Overlapping%20Ways.mapcss
+ https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1

Validator rules:
+ https://raw.githubusercontent.com/KaartGroup/KaartValidator/master/kaart.clingstone.validator.mapcss
- https://raw.githubusercontent.com/KaartGroup/KaartValidator/master/kaart.dwarf.validator.mapcss

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.
- W: Region [userProfile_BLOCK_v2]  Problem verifying disk.
- W: Region [userProfile_BLOCK_v2] Resetting cache
- W: Could not read from URL https://a.mapillary.com/v3/image_detections?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&bbox=101.6978645%2C3.102978%2C101.7051172%2C3.1130483&layers=trafficsigns&sort_by=key!: java.io.IOException: Server returned HTTP response code: 504 for URL: https://a.mapillary.com/v3/image_detections?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&bbox=101.6978645%2C3.102978%2C101.7051172%2C3.1130483&layers=trafficsigns&sort_by=key
- W: Could not read from URL https://a.mapillary.com/v3/image_detections?layers=trafficsigns&client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&_next_page_token=eyJpZCI6IjFBTm9RMjFEaXREUGtYdlZCUEJQN1EiLCJhZnRlciI6WyIxQTV1SVBscEU0Q0RNaEFxQzFYUHlKIl0sIm9mZnNldCI6MX0%3D&sort_by=key&bbox=101.6946888%2C3.0991213%2C101.7051172%2C3.1130483!: java.io.IOException: Server returned HTTP response code: 504 for URL: https://a.mapillary.com/v3/image_detections?layers=trafficsigns&client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&_next_page_token=eyJpZCI6IjFBTm9RMjFEaXREUGtYdlZCUEJQN1EiLCJhZnRlciI6WyIxQTV1SVBscEU0Q0RNaEFxQzFYUHlKIl0sIm9mZnNldCI6MX0%3D&sort_by=key&bbox=101.6946888%2C3.0991213%2C101.7051172%2C3.1130483
- W: Unable to delete archived backup file <josm.userdata>/autosave/deleted_layers/Data Layer 3_20200211_142640930.osm
- W: Could not read from URL https://a.mapillary.com/v3/image_detections?layers=trafficsigns&client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&sort_by=key&_next_page_token=eyJhZnRlciI6WyI0R3ExZ0d1SHFUdlZwalVudmpYMWVZIl0sIm9mZnNldCI6MH0%3D&bbox=101.7091513%2C3.1318602%2C101.7190647%2C3.1400019!: java.io.IOException: Server returned HTTP response code: 504 for URL: https://a.mapillary.com/v3/image_detections?layers=trafficsigns&client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&sort_by=key&_next_page_token=eyJhZnRlciI6WyI0R3ExZ0d1SHFUdlZwalVudmpYMWVZIl0sIm9mZnNldCI6MH0%3D&bbox=101.7091513%2C3.1318602%2C101.7190647%2C3.1400019
- W: Could not read from URL https://a.mapillary.com/v3/images?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&_next_page_token=eyJhZnRlciI6WzE1NzkyMzYxNDEwOTAsIjEzMUh3cE91WnRBcnI5dmJ3SUg1UFkiXX0%3D&bbox=101.7091513%2C3.1318602%2C101.7190647%2C3.1400019!: java.io.IOException: Server returned HTTP response code: 504 for URL: https://a.mapillary.com/v3/images?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&_next_page_token=eyJhZnRlciI6WzE1NzkyMzYxNDEwOTAsIjEzMUh3cE91WnRBcnI5dmJ3SUg1UFkiXX0%3D&bbox=101.7091513%2C3.1318602%2C101.7190647%2C3.1400019
- W: Could not read from URL https://a.mapillary.com/v3/image_detections?layers=trafficsigns&client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&_next_page_token=eyJhZnRlciI6WyJQZUpNRjl3NkdQNG41MHZCYlhWQ2NLIl0sIm9mZnNldCI6MH0%3D&sort_by=key&bbox=101.7091942%2C3.1331886%2C101.7182493%2C3.1399162!: java.io.IOException: Server returned HTTP response code: 504 for URL: https://a.mapillary.com/v3/image_detections?layers=trafficsigns&client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&_next_page_token=eyJhZnRlciI6WyJQZUpNRjl3NkdQNG41MHZCYlhWQ2NLIl0sIm9mZnNldCI6MH0%3D&sort_by=key&bbox=101.7091942%2C3.1331886%2C101.7182493%2C3.1399162

[Traaker_L]

Added more info on the possible cause of the crash