Duplicate relations not detected with incomplete members

[skyper]

What steps will reproduce the problem?

1. Have a relation without members downloaded
2. Duplicate relation and click on ok in relation editor
3. Run Validator

What is the expected result?

Error: Duplicated relations

What happens instead?

No error

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

It does only work if the members are downloaded.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2021-01-22 10:21:26 +0100 (Fri, 22 Jan 2021)
Revision:17475
Build-Date:2021-01-23 02:30:52
URL:https://josm.openstreetmap.de/svn/trunk

[GerdP]

Yes, the algo doesn't just compare members, it calculates and compares the geometry of relations. Without members in cannot do that. I also expected a simple member list compare, but the algo is more complex. Your case could be added, though.

[GerdP]

simple approach which may produce duplicate error messages

[GerdP]

The attached patch works for your case but doesn't pass the unit tests and produces duplocate error messages for complete relations, so it's not such a simple change.

[GerdP]

see also #20425

[stoecker]

Milestone renamed

[GerdP]

In 18976/josm:

fix #20424, fix #20425: Duplicate relations not detected with incomplete members, Duplicate Relation test is too lazy/too aggressive

• add code to compare just members so that it doesn't matter if they are complete
• change original test which compares geometry to use a list instead of a set to store members. That means that the order of members is taken into account as well as duplicated members
• before comparing tags only the "discardable" tag keys are removed, previously all "uninteresting" keys were removed, so fixme=* or note=* was ignored
• if two relations have the same members in the same order but different tags the new message informational message "Identical members" is produced.