Upload dialog should preserve all changset's tags if an open changset is the target

[skyper]

This happened to me lately where I unintentionally changed values of comment=*, source=* and created_by=*

What steps will reproduce the problem?

1. Upload a CS with comment=* and source=* set (and maybe even created_by=*) but do not close it afterwards
2. Make some more changes
3. Try to upload the additional changes to the existing CS.

What is the expected result?

JOSM automatically chooses the open CS and should fill all fields with the data from the changeset.

What happens instead?

JOSM automatically chooses the open CS but the content of the fields are not automatically filled with the existing data which can easily lead to unintended changes of the tags. Especially, created_by=* is challenging, if e.g. the reverter plugin was used.

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

Might sound like an enhancement but I have chosen defect as there is a high risk in unintentional changes of important CS's tags.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2024-11-25 23:17:46 +0100 (Mon, 25 Nov 2024)
Revision:19262
Build-Date:2024-11-27 02:30:34
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (19262 en) Linux Debian GNU/Linux 12 (bookworm)
Java version: 17.0.13+11-Debian-2deb12u1, Debian, OpenJDK 64-Bit Server VM
Look and Feel: com.formdev.flatlaf.FlatDarculaLaf

Plugins:
+ flatlaf (36349)
+ reverter (36343)
+ undelete (36349)
+ utilsplugin2 (36350)