KML: when nodes have same coordinates, only 1 is imported

[tguen]

I got a set of address data from a county government. Some taxlots have multiple addresses, which are represented by multiple tagged nodes on the taxlot with the exact same coordinates. When importing this data into JOSM as a .kml file, only one node at each set of coordinates is imported. This results in thousands of addresses being lost. This issue does not occur with .shp files.

What steps will reproduce the problem?

1. Install opendata plugin
2. Import a .kml file with multiple tagged nodes at the same location.

What is the expected result?

All nodes should be imported

What happens instead?

Only one node is imported at any point

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

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2021-08-02 19:44:04 +0200 (Mon, 02 Aug 2021)
Revision:18118
Build-Date:2021-08-02 18:26:20
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (18118 en) Linux Arch Linux
Memory Usage: 348 MB / 3984 MB (228 MB allocated, but free)
Java version: 16.0.2+7, N/A, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 2560×1440 (scaling 1.00×1.00)
Maximum Screen Size: 2560×1440
Best cursor sizes: 16×16→16×16, 32×32→32×32
Environment variable LANG: en_US.UTF-8
System property file.encoding: ANSI_X3.4-1968
System property sun.jnu.encoding: ANSI_X3.4-1968
Locale info: en_US
Numbers with default locale: 1234567890 -> 1234567890
Desktop environment: KDE
VM arguments: [-Djosm.restart=true, -Dawt.useSystemAAFontSettings=on]
Dataset consistency test: No problems found

Plugins:
+ apache-commons (35524)
+ ejml (35458)
+ geotools (35458)
+ jaxb (35543)
+ jts (35458)
+ opendata (35803)
+ utilsplugin2 (35792)

[tguen]

example kml file

[tguen]

Similarly, when importing GeoJSON, nodes with identical coordinates are inappropriately merged.
Edit: ticket for geojson - https://josm.openstreetmap.de/ticket/22352

[tguen]

I suspect the bug is here:

https://josm.openstreetmap.de/browser/osm/applications/editors/josm/plugins/opendata/src/org/openstreetmap/josm/plugins/opendata/core/io/geographic/KmlReader.java#L191