parallel ways action drops part of way when there is a loop

[GerdP]

What steps will reproduce the problem?

1. Load file
2. Select all ways
3. try to draw two parallel lines with a distance of 100m left and right

What is the expected result?

Two Lines near the original data

What happens instead?

The way on the left side is okay, the one on the right side is not.

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

Revision:19665
Is-Local-Build:true
Build-Date:2026-10-25 10:45:18

Identification: JOSM/1.5 (19665 SVN en) Windows 11 64-Bit
OS Build number: Windows 10 Pro 25H2 (26200)
Memory Usage: 1816 MB / 6144 MB (1059 MB allocated, but free)
Java version: 21.0.2+13-LTS, Azul Systems, Inc., OpenJDK 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1920x1080x32bpp@60Hz (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: UTF-8
System property sun.jnu.encoding: Cp1252
Locale info: en_DE
Numbers with default locale: 1234567890 -> 1234567890
VM arguments: [-Djpackage.app-version=1.5.19039, --add-modules=java.scripting,java.sql,javafx.controls,javafx.media,javafx.swing,javafx.web, --add-exports=java.base/sun.security.action=ALL-UNNAMED, --add-exports=java.desktop/com.sun.imageio.plugins.jpeg=ALL-UNNAMED, --add-exports=java.desktop/com.sun.imageio.spi=ALL-UNNAMED, --add-opens=java.base/java.lang=ALL-UNNAMED, --add-opens=java.base/java.nio=ALL-UNNAMED, --add-opens=java.base/jdk.internal.loader=ALL-UNNAMED, --add-opens=java.base/jdk.internal.ref=ALL-UNNAMED, --add-opens=java.desktop/javax.imageio.spi=ALL-UNNAMED, --add-opens=java.desktop/javax.swing.text.html=ALL-UNNAMED, --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED, -Djpackage.app-path=%UserProfile%\AppData\Local\JOSM\JOSM HWConsole.exe]
Dataset consistency test: No problems found

Plugins:
+ OpeningHoursEditor (36493)
+ apache-commons (36483)
+ buildings_tools (36503)
+ comfort0 (36483)
+ ejml (36483)
+ geotools (36483)
+ jackson (36502)
+ jaxb (36483)
+ jts (36483)
+ o5m (36493)
+ opendata (36503)
+ pbf (36493)
+ photo_geotagging (36503)
+ poly (36483)
+ reverter (36503)
+ terracer (36503)
+ undelete (36503)
+ utilsplugin2 (36503)

Tagging presets:
+ c:\josm\core\resources\data\defaultpresets.xml

Map paint styles:
- c:\josm\core\resources\styles\standard\elemstyles.mapcss

Validator rules:
+ d:\java_tools\JOSM\mygeometry.mapcss
+ https://josm.openstreetmap.de/josmfile?page=Rules/GermanySpecific&zip=1
+ c:\josm\core\resources\data\validator\combinations.mapcss
+ c:\josm\core\resources\data\validator\geometry.mapcss

Last errors/warnings:
- 00000.821 W: extended font config - overriding 'filename.Malgun_Gothic=malgun.ttf' with 'MALGUN.TTF'
- 00000.823 W: extended font config - overriding 'filename.Myanmar_Text=mmrtext.ttf' with 'MMRTEXT.TTF'
- 00000.824 W: extended font config - overriding 'filename.Mongolian_Baiti=monbaiti.ttf' with 'MONBAITI.TTF'
- 00001.376 E: java.security.KeyStoreException: Windows-ROOT not found. Cause: java.security.NoSuchAlgorithmException: Windows-ROOT KeyStore not available
- 00001.705 W: Missing plugin main version in plugin mapwithai
- 00003.615 W: Missing plugin main version in plugin mapwithai

[GerdP]

test data (members of a route relation)