validator is very slow when validating a complete complex multipolygon

[GerdP]

What steps will reproduce the problem?

1. Load a complex multipolygon relation with all members (relation 1205151 Lake Huron)
2. Enable preference "show informational level"
3. run validator
4. see that geometry.mapcss rules shows no progress
5. cancel validator (works fine)
6. select the multipolygon relation
7. run validator
8. see that geometry.mapcss rules shows no progress
9. cancel validator doesn't seem to work

What is the expected result?

• progress bar should show some progress
• due to the complexity of the relation the tests cannot complete within a second, but more than a minute seems too long. Maybe this could be detected somehow so that complex relation is excluded from the tests.

What happens instead?

• progress bar doesn't change for many seconds
• validations takes many minutes, probably hours (didn't wait for the result)

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

Main performance killer is this test:

area:closed:areaStyle ⧉ area:closed:areaStyle {
  throwOther: tr("Overlapping Areas");
}

Maybe we can avoid to test members of multipolygon relations against the parent relation?

Build-Date:2020-07-30 09:57:31
Revision:16809
Is-Local-Build:true

Identification: JOSM/1.5 (16809 SVN en) Windows 10 64-Bit
OS Build number: Windows 10 Home 1903 (18362)
Memory Usage: 929 MB / 1753 MB (455 MB allocated, but free)
Java version: 1.8.0_191-b12, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1920x1080 (scaling 1.0x1.0)
Maximum Screen Size: 1920x1080
Best cursor sizes: 16x16 -> 32x32, 32x32 -> 32x32
VM arguments: [-agentlib:jdwp=transport=dt_socket,suspend=y,address=localhost:56288, -ea, -Dfile.encoding=UTF-8]
Program arguments: [--debug]
Dataset consistency test: No problems found

Plugins:
+ OpeningHoursEditor (35414)
+ PolygonCutOut (v0.7)
+ apache-commons (35362)
+ buildings_tools (35500)
+ continuosDownload (91)
+ ejml (35313)
+ geotools (35169)
+ jaxb (35092)
+ jts (35122)
+ merge-overlap (35248)
+ o5m (35248)
+ opendata (35513)
+ pbf (35446)
+ poly (35248)
+ reverter (35499)
+ undelete (35499)
+ utilsplugin2 (35487)