Check waterway flow direction

[anonymous]

What steps will reproduce the problem?

1. Recreate the following as on the picture
2. Run the validator

What is the expected result?

JOSM should warn about the middle drain because it has drawn in the wrong direction (also see #12646).

What happens instead?

Nothing.

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2019-03-26 22:46:08 +0100 (Tue, 26 Mar 2019)
Build-Date:2019-03-27 02:30:53
Revision:14936
Relative:URL: ^/trunk

Identification: JOSM/1.5 (14936 hu) Windows 10 64-Bit
OS Build number: Windows 10 Pro 1809 (17763)
Memory Usage: 718 MB / 1820 MB (516 MB allocated, but free)
Java version: 1.8.0_201-b09, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1200
Maximum Screen Size: 1920x1200
VM arguments: [-Djava.security.manager, -Djava.security.policy=file:<java.home>\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>\bin, -Djnlpx.origFilenameArg=%UserProfile%\AppData\LocalLow\Sun\Java\Deployment\cache\6.0\31\583aa85f-6f9da138, -Djnlpx.remove=false, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.heapsize=NULL,2048m, -Djnlpx.splashport=50584, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm-latest.jnlp, -Djnlpx.jvm=<java.home>\bin\javaw.exe]
Dataset consistency test: No problems found

Plugins:
+ OpeningHoursEditor (34867)
+ apache-commons (34506)
+ continuosDownload (82)
+ ejml (34389)
+ geotools (34513)
+ jaxb (34678)
+ jts (34524)
+ opendata (34911)
+ reverter (34946)
+ tag2link (34867)
+ tageditor (34867)
+ turnlanes-tagging (280)
+ utilsplugin2 (34932)
+ wikipedia (v1.1.1)

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

Validator rules:
+ https://josm.openstreetmap.de/josmfile?page=Rules/OsmoseValidations&zip=1

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.