id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
18462	[Patch RFC] JOSM doesn't use preferences.xml_backup	GerdP	team	"==== What steps will reproduce the problem?
1. Stop JOSM
2. Edit preferences.xml and remove all but the first 4 lines to simulate a previous crash of JOSM
3. Start JOSM

==== What is the expected result?
JOSM detects invalid preferences.xml and valid preferences.xml_backup and uses the backup.

==== What happens instead?
Popup saying that the preferences.xml was bad and that a new file is created with defaults.
[[Image(bak.png)]]

==== Please provide any additional information below. Attach a screenshot if possible.
See also german forum https://forum.openstreetmap.org/viewtopic.php?id=68309
It seems JOSM never tries to use the backup and it is likely that the user will overwrite this good copy before they really understand what happened. 
{{{
URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2019-12-01 23:10:15 +0100 (Sun, 01 Dec 2019)
Build-Date:2019-12-02 02:30:57
Revision:15553
Relative:URL: ^/trunk

Identification: JOSM/1.5 (15553 de) Windows 10 64-Bit
OS Build number: Windows 10 Home 1903 (18362)
Memory Usage: 674 MB / 4551 MB (145 MB allocated, but free)
Java version: 1.8.0_221-b11, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1080
Maximum Screen Size: 1920x1080

Last errors/warnings:
- E: org.xml.sax.SAXParseException: XML-Dokumentstrukturen müssen innerhalb derselben Entity beginnen und enden.
- W: No configuration settings found.  Using hardcoded default values for all pools.
}}}
"	defect	closed	normal	20.05	Core		fixed	template_report