Warn about placing a surface marker as member of underground pipeline or cable

[francois.lacombe]

Dear maintainers

Markers are currently mapped as nodes with marker=* key. They often warns about the presence of underground infrastructure.
Wiki states it's not recommended to map those markers nodes as members of underground pipeline or cables ways.
​https://wiki.openstreetmap.org/wiki/Key:marker
​https://wiki.openstreetmap.org/wiki/File:Guideline_markers_underground_pipelines.png

Is it possible to add a validation warning please, when a marker is part of a way with
man_made=pipeline + location=underground
power=cable + location=underground

There is no problem for markers to be members of pipelines/cables ways when such pipeline is overground and the marker is installed directly on it.
When pipelines are underground, markers aren't directly linked nor involved in operation (like a valve can be for instance) so the node should be added apart.
(it would be weird to get the marker buried with the pipeline it is supposed to warn about)

Thanks in advance

[Klumbumbus]

In 15964/josm:

fix #18817 - Warn about marker as member of underground pipeline or cable

[francois.lacombe]

This is so quick, wow

Thank you :)