Command line output unreadable on Windows

[gaben]

What steps will reproduce the problem?

1. Use Windows, set lang to Hungarian (maybe you can skip this step)
2. Set command line encoding from default to UTF-8 (maybe you can skip this step)
3. Set JOSM language to Hungarian
4. Start JOSM from command line (cmd or powershell, doesn't matter):

java -jar "josm-snapshot-15752.jar"

What is the expected result?

Readable output with valid characters.

What happens instead?

JOSM printing invalid characters and it's not readable easily. See below:

2020-01-23 17:28:11.200 INFO: Naplˇzßsi szint: INFO (INFO, 800)
2020-01-23 17:28:11.370 INFO: Removed preference default remotecontrol.https.enabled since it is no longer used
2020-01-23 17:28:11.428 INFO: Saved updated default preferences.
2020-01-23 17:28:11.853 INFO: IPv6 hßlˇzat Úszlelve; IPv6 preferßlßsa IPv4 ellenÚben.
2020-01-23 17:28:12.777 INFO: 'jaxb' b§vÝtmÚny bet÷ltÚse (35092 verziˇ)
2020-01-23 17:28:13.171 INFO: Reassigning shortcut 'file:download_along' from null to 640 because of conflict with Alt+Shift+D
2020-01-23 17:28:13.172 INFO: Csendes gyorsbillentyű konfliktus: 'file:download_along' ßtmozgatßsra kerŘlt 'continuosdownload:activate'-r§l 'Ctrl+Alt+F1'-re.
2020-01-23 17:28:13.539 INFO: GET https://api.openstreetmap.org/api/0.6/user/details -> HTTP_1 200 (683 B)
2020-01-23 17:28:14.040 INFO: GET https://josm.openstreetmap.de/wiki/Hu:StartupPage -> HTTP_1 200
2020-01-23 17:28:14.120 INFO: Obtained 51 Tag2Link rules from https://query.wikidata.org/sparql
2020-01-23 17:28:14.175 INFO: Obtained 11 Tag2Link rules from https://sophox.org/sparql
2020-01-23 17:28:14.408 INFO: "Bing műholdkÚp" lÚgifelvÚtel frissÝtÚse
2020-01-23 17:28:14.408 INFO: "Esri World Imagery" lÚgifelvÚtel frissÝtÚse
2020-01-23 17:28:14.410 INFO: "Esri World Imagery (Clarity) Beta" lÚgifelvÚtel frissÝtÚse

For example, the first entry is
2020-01-23 17:28:11.200 INFO: Naplˇzßsi szint: INFO (INFO, 800)
instead of
2020-01-23 17:28:11.200 INFO: Naplózási szint: INFO (INFO, 800)

Older JOSM versions work fine. I checked r10526 and it printed readable characters. If I remember correctly I switched the terminal encoding from Windows default to UTF-8 a while ago, but I'm not sure.

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

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-01-22 22:31:24 +0100 (Wed, 22 Jan 2020)
Build-Date:2020-01-23 02:30:55
Revision:15752
Relative:URL: ^/trunk

Identification: JOSM/1.5 (15752 hu) Windows 10 64-Bit
OS Build number: Windows 10 Pro 1909 (18363)
Memory Usage: 1066 MB / 1820 MB (666 MB allocated, but free)
Java version: 1.8.0_231-b11, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1200
Maximum Screen Size: 1920x1200
VM arguments: [-Djava.security.manager, -Djava.security.policy=file:<java.home>\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>\bin, -Djnlpx.origFilenameArg=%UserProfile%\AppData\LocalLow\Sun\Java\Deployment\cache\6.0\31\583aa85f-3ed5e881, -Djnlpx.remove=false, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.heapsize=NULL,2048m, -Djnlpx.splashport=57967, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm-latest.jnlp, -Djnlpx.jvm=<java.home>\bin\javaw.exe]