[Patch] Change in multipolygon is not recognized by MultipolygonCache

[GerdP]

What steps will reproduce the problem?

1. Load attached unglue.osm
2. Select the node where the inner and outer ring intersect
3. Press 'G' to unglue, a popup says "Unglueing effected one relation" (which is correct)
4. Select the node, keep left mouse button pressed and move the node a bit to the north
5. Select the rightmost way
6. Select the unglued node, keep left mouse button pressed and move the node close to the other

one from step 4

7. Press "M" to merge the nodes and therefor close the outer ring.
8. Press "Shift+V" to run validator

What is the expected result?

no warning message

What happens instead?

Warning "Multipolygon is not closed (1)"

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

When I open the relation in the relation editor and change the order of the ways and save that the validator no longer complains. I think the problem here is that the MultipolygonCache is not updated when the nodes are merged in step 7.
I'll try to find a fix for this.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2016-09-06 00:16:07 +0200 (Tue, 06 Sep 2016)
Build-Date:2016-09-05 22:21:00
Revision:10966
Relative:URL: ^/trunk

Identification: JOSM/1.5 (10966 en) Windows 10 64-Bit
Memory Usage: 2402 MB / 5461 MB (2214 MB allocated, but free)
Java version: 1.8.0_102-b14, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1080
Maximum Screen Size: 1920x1080
VM arguments: [-XX:StartFlightRecording=name=MyRecording2,settings=d:\dbg\gerd.jfc, -XX:FlightRecorderOptions=defaultrecording=true,dumponexit=true,dumponexitpath=e:\ld\perf_20160908_153418.jfr]
Dataset consistency test: No problems found

Plugins:
+ FastDraw (32938)
+ apache-commons (32699)
+ buildings_tools (32944)
+ ejml (32680)
+ geotools (32813)
+ jts (32699)
+ o5m (32857)
+ opendata (32898)
+ pbf (32865)
+ poly (32699)
+ reverter (32796)
+ utilsplugin2 (32815)

Map paint styles:
+ https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1

[GerdP]

No idea how to fix this. Here is what I found:
The UnGlueAction somehow creates a TagsChangedEvent for the two outer ways, and this triggers a
call of MultipolygonCache.removeMultipolygonFrom(Relation r, Collection<Map<Relation, Multipolygon>> maps) which means the
polygon is calculated again next time and the field Multipolygon.openEnds is filled.
The MergeNodesAction doesn't trigger such a call. The MultipolygonTest uses Multipolygon.getOpenEnds() and sees out-aged data.

[GerdP]

I've found a fix, see attached patch. The problem always occurs when the nodes of multipolygon way are changed so that an inner or outer ring which was unclosed is now closed. The patch detects this and removes the polygon from the cache to make sure that it is recalculated with next use.

[simon04]

In 11117/josm:

fix #13591 - Change in multipolygon is not recognized by MultipolygonCache (patch by Gerd Petermann)

[simon04]

Thank you for the patch, but also for showing me that Shift+V runs the validator, and M merges the solely selected node into a very close one.