id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
18928	JOSM crashes when data contains way without nodes	GerdP	Don-vip	"==== What steps will reproduce the problem?
1. load attached file
2. run validator
3. select way that produces the error ""empty line"" w43935619
4. Press Q (Orthogonalize Shape) or L (Align nodes) or R (Reverse way)

==== What is the expected result?
no action or maybe a warning that way has no nodes
==== What happens instead?
different crash reports
==== Please provide any additional information below. Attach a screenshot if possible.
I've noticed that `Multipolygon.joinWays()` will loop forever when a way with 0 nodes is in the collection and wondered why nobody noticed this so far.
Not sure if this can be reproduced without manipulating an *.osm file in an editor like I did with the attached file.
No idea where this should be fixed. 

{{{
Build-Date:2020-03-14 10:00:19
Revision:16117
Is-Local-Build:true

Identification: JOSM/1.5 (16117 SVN en) Windows 10 64-Bit
OS Build number: Windows 10 Home 1903 (18362)
Memory Usage: 686 MB / 1753 MB (261 MB allocated, but free)
Java version: 1.8.0_191-b12, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1080
Maximum Screen Size: 1920x1080
VM arguments: [-agentlib:jdwp=transport=dt_socket,suspend=y,address=localhost:50962, -ea, -Dfile.encoding=UTF-8]
Program arguments: [--debug]

Dataset consistency test:
[WARN - ZERO NODES] Way {Way id=43935619 version=1 V nodes=[]} has zero nodes


Plugins:
+ OpeningHoursEditor (35250)
+ PolygonCutOut (v0.7)
+ apache-commons (35092)
+ buildings_tools (35248)
+ continuosDownload (91)
+ ejml (35122)
+ geotools (35169)
+ jaxb (35092)
+ jts (35122)
+ merge-overlap (35248)
+ o5m (35248)
+ opendata (35330)
+ pbf (35248)
+ poly (35248)
+ reverter (35313)
+ undelete (35313)
+ utilsplugin2 (35334)

Last errors/warnings:
- E: Handled by bug report queue: java.lang.NegativeArraySizeException
- E: Handled by bug report queue: java.lang.IllegalArgumentException: New way {Way id=43935619 version=1 V nodes=[]} has 0 nodes
- E: Handled by bug report queue: java.lang.NullPointerException
- E: Handled by bug report queue: java.lang.NullPointerException
- E: Handled by bug report queue: java.lang.NullPointerException
- E: Handled by bug report queue: java.lang.NullPointerException
- E: Handled by bug report queue: java.lang.NegativeArraySizeException
- E: Handled by bug report queue: java.lang.IllegalArgumentException: New way {Way id=43935619 version=1 V nodes=[]} has 0 nodes
}}}
"	defect	closed	normal	20.03	Core		fixed	template_report