id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
20115	Create Multipolygon: Strange relation editor entries in window menu which can lead to a stall	skyper	team	"==== What steps will reproduce the problem?
1. Create Multipolygon with `multipoly.show-relation-editor`
1. Close the relation editor
1. Have mysterious relation editor entry at the bottom of the window menu
1. Delete layer
1. Click on relation editor entry in windows menu
1. In the now open relation editor click on cancel
1. In the following unsaved changes dialog click on anything

==== What is the expected result?
Some reaction

==== What happens instead?
No reaction. I cannot close the window.
Only creating more identical windows is possible and the JOSM session is unusable.

==== Please provide any additional information below. Attach a screenshot if possible. 
I had play around with ""create multipolygon"" in this session and used redo/undo in different layers with possible open relation editors. I probably did even delete layers with open relation editors with unsaved changes. The relation looked like one of this relations where the layer was already deleted.

For the chance that it can help I'll attach a [attachment:dump.txt dump].

{{{
Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-11-18 20:16:58 +0100 (Wed, 18 Nov 2020)
Revision:17323
Build-Date:2020-11-19 02:30:51
URL:https://josm.openstreetmap.de/svn/trunk
}}}"	defect	closed	critical	20.11	Core	latest	fixed	template_report relation editor deleted layer create multipolygon