Reproducibly failing to open folder certain folder with cyrillic filename

[streamx3@…]

What steps will reproduce the problem?

1. Install JOSM in ubuntu from SNAP
2. Press open icon
3. Navigate to folder with cyrillic filename

What is the expected result?

Folder opens and I get to my GPX data

What happens instead?

I get an error message and get to this page

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

Those unmappable characters are most likely "Етапи розробки.txt"
And VERY IMPORTAND THING: This can only be reproduced with SNAP version.
Same version launched through java -jar works fine.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-09-06 16:54:59 +0200 (Sun, 06 Sep 2020)
Revision:17013
Build-Date:2020-09-07 01:30:48
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (17013 en) Linux Ubuntu 20.04.1 LTS
Memory Usage: 326 MB / 3988 MB (99 MB allocated, but free)
Java version: 11.0.8+10-post-Ubuntu-0ubuntu118.04.1, Ubuntu, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 2560x1440 (scaling 1.0x1.0)
Maximum Screen Size: 2560x1440
Best cursor sizes: 16x16 -> 16x16, 32x32 -> 32x32
Desktop environment: XFCE
VM arguments: [-Duser.home=${HOME}]

Last errors/warnings:
- 00015.677 E: Handled by bug report queue: java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters: /home/<user.name>/SynologyDrive/Drive/���������� ����������������.txt


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

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: Basic L&F File Loading Thread (57)
java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters: /home/s13/SynologyDrive/Drive/���������� ����������������.txt
	at java.base/sun.nio.fs.UnixPath.encode(UnixPath.java:145)
	at java.base/sun.nio.fs.UnixPath.<init>(UnixPath.java:69)
	at java.base/sun.nio.fs.UnixFileSystem.getPath(UnixFileSystem.java:279)
	at java.base/java.nio.file.Path.of(Path.java:147)
	at java.base/java.nio.file.Paths.get(Paths.java:69)
	at java.desktop/sun.awt.shell.ShellFolder.getShellFolder(ShellFolder.java:247)
	at java.desktop/javax.swing.filechooser.FileSystemView.getFiles(FileSystemView.java:523)
	at java.desktop/javax.swing.plaf.basic.BasicDirectoryModel$FilesLoader.run0(BasicDirectoryModel.java:290)
	at java.desktop/javax.swing.plaf.basic.BasicDirectoryModel$FilesLoader.run(BasicDirectoryModel.java:279)
	at java.base/java.lang.Thread.run(Thread.java:834)

[stoecker]

Closed as duplicate of #14596.
Seems your system does not properly tell JOSM the used character encoding. Closing as duplicate of the well-known problem when using LANG=C instead of LANG=C.UTF-8 (or similar).

If this is not the case: Reopen with a specific description how you start josm and which language and environment settings you have.

[mvogt]

Thanks for this bugreport. The snap should not change LANG by itself so I would love to understand a bit more about this issue, could you please paste the output of the "locale" command to this bugreport? And the Ubuntu release you are using? I will try to reproduce with your setting then.