Error when pressing "c" to combine ways.

[v0174@…]

What steps will reproduce the problem?

1. Select ways 827845889 and 225476585
2. Press "c"

What is the expected result?

Ways are combined

What happens instead?

An error message appears.

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: 2020-06-30 19:13:42 +0200 (Tue, 30 Jun 2020)
Build-Date:2020-07-01 01:30:51
Revision:16731
Relative:URL: ^/trunk

Identification: JOSM/1.5 (16731 cs) Windows 10 64-Bit
OS Build number: Windows 10 Home 1903 (18362)
Memory Usage: 1061 MB / 1820 MB (869 MB allocated, but free)
Java version: 1.8.0_251-b08, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1920x1080 (scaling 1.0x1.0)
Maximum Screen Size: 1920x1080
Best cursor sizes: 16x16 -> 32x32, 32x32 -> 32x32
VM arguments: [-Djava.security.manager, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm.jnlp, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlp.tk=awt, -Djnlpx.jvm=<java.home>\bin\javaw.exe, -Djnlpx.splashport=61760, -Djnlpx.home=<java.home>\bin, -Djnlpx.remove=false, -Djnlpx.offline=false, -Djnlpx.relaunch=true, -Djnlpx.session.data=%UserProfile%\AppData\Local\Temp\session2258788154349401517, -Djnlpx.heapsize=-1,2147483648, -Djava.security.policy=file:<java.home>\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.origFilenameArg=%UserProfile%\AppData\LocalLow\Sun\Java\Deployment\cache\6.0\56\1ee8cfb8-101c93dd]
Dataset consistency test: No problems found

Plugins:
+ DirectUpload (35499)
+ OpeningHoursEditor (35414)
+ Tracer (35313)
+ apache-commons (35362)
+ apache-http (35092)
+ buildings_tools (35500)
+ editgpx (35248)
+ ejml (35313)
+ geotools (35169)
+ imagery_offset_db (35405)
+ jaxb (35092)
+ jna (35092)
+ jts (35122)
+ log4j (35092)
+ measurement (35405)
+ photo_geotagging (35499)
+ poly (35248)
+ reltoolbox (35405)
+ routes (35405)
+ utilsplugin2 (35487)

Last errors/warnings:
- E: org.openstreetmap.josm.data.osm.search.SearchParseError: Neočekávaný token: <rovná se>
- E: org.openstreetmap.josm.data.osm.search.SearchParseError: Neočekávaný token: <rovná se>
- E: org.openstreetmap.josm.data.osm.search.SearchParseError: Neočekávaný token: <rovná se>
- E: org.openstreetmap.josm.data.osm.search.SearchParseError: Neočekávaný token: <rovná se>
- E: Handled by bug report queue: java.lang.UnsupportedOperationException


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

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: AWT-EventQueue-2 (53) of javawsApplicationThreadGroup
java.lang.UnsupportedOperationException
	at java.util.Collections$UnmodifiableList.set(Unknown Source)
	at java.util.Collections.swap(Unknown Source)
	at java.util.Collections.reverse(Unknown Source)
	at org.openstreetmap.josm.actions.CombineWayAction.combineWaysWorker(CombineWayAction.java:160)
	at org.openstreetmap.josm.actions.CombineWayAction.actionPerformed(CombineWayAction.java:300)
	at javax.swing.SwingUtilities.notifyAction(Unknown Source)
	at javax.swing.JComponent.processKeyBinding(Unknown Source)
	at javax.swing.KeyboardManager.fireBinding(Unknown Source)
	at javax.swing.KeyboardManager.fireKeyboardAction(Unknown Source)
	at javax.swing.JComponent.processKeyBindingsForAllComponents(Unknown Source)
	at javax.swing.JComponent.processKeyBindings(Unknown Source)
	at javax.swing.JComponent.processKeyEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source)
	at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source)
	at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Source)
	at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown Source)
	at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
	at java.awt.EventQueue.access$500(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)

[GerdP]

Closed as duplicate of #19485.