Allow independent area style for outer ways of multipolygons

[Klumbumbus]

What steps will reproduce the problem?

1. download the area around ​way/95017851
2. see how this building has no fill color (which it had in previous josm versions).

This is caused by the relation ​relation/1375010. Despite this relation has no "physical tag" and it is questionable if it should have one, nevertheless it should not hide the fill color of the correct tagged linked building.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2017-05-21 01:45:26 +0200 (Sun, 21 May 2017)
Build-Date:2017-05-21 00:28:16
Revision:12222
Relative:URL: ^/trunk

Identification: JOSM/1.5 (12222 de) Windows 10 64-Bit
OS Build number: Windows 10 Pro 1607 (14393)
Memory Usage: 1273 MB / 3641 MB (670 MB allocated, but free)
Java version: 1.8.0_131-b11, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1680x1050
Maximum Screen Size: 1680x1050
VM arguments: [-Djava.security.manager, -Djava.security.policy=file:<java.home>\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>\bin, -Djnlpx.origFilenameArg=C:\Program Files (x86)\josm-latest-mehr-RAM.jnlp, -Djnlpx.remove=true, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.heapsize=1024m,4096m, -Djnlpx.splashport=59078, -Djnlpx.jvm=<java.home>\bin\javaw.exe]
Dataset consistency test: No problems found

Plugins:
+ AddrInterpolation (33160)
+ DirectDownload (33160)
+ DirectUpload (33182)
+ FastDraw (33182)
+ HouseNumberTaggingTool (33160)
+ Mapillary (v1.5.3)
+ OpeningHoursEditor (33185)
+ Tracer2 (33004)
+ alignways (33182)
+ apache-commons (32994)
+ apache-http (32699)
+ buildings_tools (33004)
+ contourmerge (1030)
+ editgpx (33004)
+ imagery-xml-bounds (33276)
+ imagery_offset_db (33316)
+ jogl (1.0.46)
+ log4j (32699)
+ measurement (33088)
+ osm-obj-info (1484152384)
+ photo_geotagging (33088)
+ photoadjust (33303)
+ reltoolbox (33311)
+ reverter (33088)
+ tag2link (33035)
+ tageditor (33021)
+ tagging-preset-tester (33004)
+ terracer (33088)
+ turnlanes-tagging (254)
+ turnrestrictions (33088)
+ undelete (33263)
+ utilsplugin2 (33297)
+ wikipedia (33288)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/OneClick&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/StolpersteineLight&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/NewTags&zip=1
+ %UserProfile%\Documents\OSM\josm\data\defaultpresets.xml
+ https://raw.githubusercontent.com/yopaseopor/traffic_signs_preset_JOSM/master/DE.zip
+ https://josm.openstreetmap.de/josmfile?page=Presets/Industrial&zip=1
+ http://somewhere.dk/email/josm/source.xml

Map paint styles:
- %UserProfile%\Documents\OSM\josm\styles\standard\elemstyles.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/HiDPISupport&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Maxspeed&zip=1
- %UserProfile%\Documents\OSM\eigene styles\maxspeed\maxspeed_2.8_01 zeige richtungspfeile.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/sac_scale&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/ShowID&zip=1
- %UserProfile%\Documents\OSM\eigene styles\PriorityRoad\PriorityRoad_1.0.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/LayerChecker&zip=1
- %UserProfile%\Documents\OSM\eigene styles\layer checker\layer checker_1.2.mapcss
- %UserProfile%\Documents\OSM\TestNew\newicons.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/Surface&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/ParkingLanes&style&zip=1
- %UserProfile%\Documents\OSM\patches\old MPs\dataquality.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/Sidewalks&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Cycleways&style&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Osmc&style&zip=1
- https://raw.githubusercontent.com/species/josm-preset-wheelchair/master/sidewalks_kerbs.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/LitObjects&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Lit&style&zip=1
- %UserProfile%\Documents\OSM\eigene styles\Tourenplanung.mapcss
- %UserProfile%\Documents\OSM\eigene styles\SpecificBuildingValues\SpecificBuildingValues.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_buildings&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Modified&zip=1
- https://github.com/bastik/mapcss-tools/raw/osm/mapnik2mapcss/osm-results/mapnik.zip
- %UserProfile%\Documents\OSM\eigene styles\area-symbol.zip
- http://www.freietonne.de/ft_icons/josm/FreieTonne_rules_presets_zip.php
- https://josm.openstreetmap.de/josmfile?page=Styles/NewHighwayColors&zip=1
- http://www.openrailwaymap.org/styles/standard.zip
- https://josm.openstreetmap.de/josmfile?page=Styles/MaxspeedIcons&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/DestinationSignRelation&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/ParkingLanes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Incline&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/PTStops&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/AdvertisingStyle&zip=1
- https://www.dropbox.com/s/qo3ai47fpv241jf/Styles_Fixme_and_Notes.zip?raw=1
- https://github.com/gmgeo/osmic-josm-style/archive/master.zip
- https://josm.openstreetmap.de/josmfile?page=Styles/hazmat&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Suburb&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Postcode&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/RecyclingMaterials&zip=1

Validator rules:
+ https://raw.githubusercontent.com/<user.name>n-a-bauer/josm-validators/master/mtb.validator.mapcss
+ %UserProfile%\Documents\OSM\TestNew\new.validator.mapcss
+ https://josm.openstreetmap.de/josmfile?page=Rules/GermanySpecific&zip=1
- %UserProfile%\Documents\OSM\TestNew\germ.validator.mapcss
- https://josm.openstreetmap.de/josmfile?page=Rules/CzechRepublicAddressSystem&zip=1

Last errors/warnings:
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet

[stoecker]

I'm not sure about this case.

Currently we do not draw area style of an outer way to an multipolygon.

I'm not sure if fixing this is a bug or a feature. If we fix this, then we will encourage using drawing style on outers of multipolygons and in 99% of all cases (like in this case here) this will be wrong.

OTOH, with the old style multipolygons gone it would be logical to fully decouple the drawing of outer way area style and the multipolygon...

[Klumbumbus]

Hm. I think when the multipolygon alone doesn't "produce any drawing" like in this case then it should be ignored completely for drawing and therefore not influence the drawing of other objects. The single buildings should get their drawing from their own tags (in this case from building=* and then overwritten from office=*) and not from an invalid multipolygon.

[stoecker]

Replying to Klumbumbus:

Hm. I think when the multipolygon alone doesn't "produce any drawing" like in this case then it should be ignored completely

No. That is a workaround for broken data. The whole idea of fixing the old-style stuff was to get rid of such crap.

[bastiK]

As said, the tagging is incomplete in this case: Multipolygon relation with a name=* tag is just like a closed way with no more than a single name=* tag.

Replying to stoecker:

OTOH, with the old style multipolygons gone it would be logical to fully decouple the drawing of outer way area style and the multipolygon...

+1, this sounds simple and logical. Maybe there is the disadvantage, that tagging the outer ways is not discouraged as much. But it is the validator's job to point out these kind of errors, not (necessarily) the renderer's.

[stoecker]

Replying to bastiK:

As said, the tagging is incomplete in this case: Multipolygon relation with a name=* tag is just like a closed way with no more than a single name=* tag.

It is not incomplete. It is wrong. A multipolygon describes an area. We have a polygon area description of three individual rings here, which we draw (empty) and 3 area descriptions of individual rings which we do not draw. The solution in this case is simple: Drop the wrong multipolygon.

Replying to stoecker:

OTOH, with the old style multipolygons gone it would be logical to fully decouple the drawing of outer way area style and the multipolygon...

+1, this sounds simple and logical. Maybe there is the disadvantage, that tagging the outer ways is not discouraged as much. But it is the validator's job to point out these kind of errors, not (necessarily) the renderer's.

Validator is often ignored. Cases where outer way area styles for multipolygons are valid are extremely seldom. I prefer the current method which shows the bug directly. If it is not shown people will fix it.

[bastiK]

Replying to stoecker:

Replying to bastiK:

As said, the tagging is incomplete in this case: Multipolygon relation with a name=* tag is just like a closed way with no more than a single name=* tag.

It is not incomplete. It is wrong. A multipolygon describes an area. We have a polygon area description of three individual rings here, which we draw (empty) and 3 area descriptions of individual rings which we do not draw. The solution in this case is simple: Drop the wrong multipolygon.

The idea here is to record the Kreisverwaltungsbehörde as an entity (which may have a wikidata id) in addition to individual buildings with specialized properties (like you would for university or school). Not sure how to do this properly, but by dropping the relation, this information would be lost.

[Klumbumbus]

Replying to bastiK:

Not sure how to do this properly

Maybe with a ​site relation

[stoecker]

This building grouping using multipolygons actually is a very common error.

[stoecker]

Reconsider for 18.04 maybe?

[Don-vip]

Do it when you want :) I simply removed the milestone as there is no need to delaying it constantly if nobody's working on it.

[stoecker]

#15360 handles the aspect to also cancel the "area style on outer member" validator warning.