Changing selection outside relation editor selects all instances of a duplicated member inside editor

[ShadowFoxNixill]

What steps will reproduce the problem?

1. Open or download a map
2. Create a relation with multiple copies of one or more members (for this example we'll say the relation gets set up as nodes A, B, C, D, B, A)
3. Select the first instance of a member in the relation list (for this example, the first node A).
4. Select something on the map (let's call that node E).
5. Click "insert after" in the relation editor

What is the expected result?

[After step 4] The selection should remain at just the first A.
[After step 5] Node E should be the second member of the relation - A, E, B, C, D, B, A

What happens instead?

[After step 4] All instances of node A are selected in the relation editor.
[After step 5] Node E is the final member of the relation - A, B, C, D, B, A, E

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: 2019-02-19 01:17:05 +0100 (Tue, 19 Feb 2019)
Build-Date:2019-02-19 02:30:51
Revision:14795
Relative:URL: ^/trunk

Identification: JOSM/1.5 (14795 en) Windows 10 64-Bit
OS Build number: Windows 10 Education 1803 (17134)
Memory Usage: 1374 MB / 1820 MB (447 MB allocated, but free)
Java version: 1.8.0_201-b09, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1080, \Display1 1920x1080
Maximum Screen Size: 1920x1080
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%\Programs\josm-latest.jnlp, -Djnlpx.remove=false, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.heapsize=NULL,2048m, -Djnlpx.splashport=57834, -Djnlpx.jvm=<java.home>\bin\javaw.exe]
Dataset consistency test: No problems found

Plugins:
+ apache-commons (34506)
+ continuosDownload (82)
+ ejml (34389)
+ geotools (34513)
+ jaxb (34678)
+ jts (34524)
+ opendata (34867)
+ pbf (34867)
+ utilsplugin2 (34867)

Map paint styles:
+ https://github.com/bastik/mapcss-tools/raw/osm/mapnik2mapcss/osm-results/mapnik.zip

Last errors/warnings:
- E: java.net.SocketTimeoutException: connect timed out
- W: org.openstreetmap.josm.io.OsmTransferException: Could not connect to the OSM server. Please check your internet connection.. Cause: java.net.SocketTimeoutException: connect timed out
- W: java.net.SocketTimeoutException: connect timed out
- W: Already here java.net.SocketTimeoutException: connect timed out
- E: java.net.SocketTimeoutException: connect timed out
- W: org.openstreetmap.josm.io.OsmTransferException: Could not connect to the OSM server. Please check your internet connection.. Cause: java.net.SocketTimeoutException: connect timed out
- W: java.net.SocketTimeoutException: connect timed out
- W: Already here java.net.SocketTimeoutException: connect timed out
- E: java.net.SocketTimeoutException: connect timed out
- W: org.openstreetmap.josm.io.OsmTransferException: Could not connect to the OSM server. Please check your internet connection.. Cause: java.net.SocketTimeoutException: connect timed out

[Hb---]

Confirmed on fresh install.

[skyper]

Yes this is a pain when working on route relations with loops.