warn on waterway and highway shared node that is not a ford

[aceman]

Currently JOSM properly warns when a waterway and a highway with the same layer intersect without a shared node. The user is supposed to make a bridge, culvert or a ford. But it is possible to silence this warning by adding a shared node, without any tags. Such a 'fake ford' makes JOSM happy, but introduces invalid data. Waterway and highway aren't normally supposed to meet in the same vertical level. One exception is a ford, but then it needs a ford=yes tag.

I suggest JOSM also issues a warning if that shared node has no tags.
Maybe there are other cases different from ford where the ways meet in a shared node (maybe e.g. a weir) so it is up to you whether any tag is enough to fix the warning, or it must be ford=yes specifically.

Also note the ford=yes can be tagged on the way inside the riverbanks, in which case the shared node will still exist, but not have the ford=yes tag itself. JOSM shold cover this case and not issue the warning either.

See ​https://wiki.openstreetmap.org/wiki/Tag:ford%3Dyes .

[Hb---]

Replying to aceman:

Also note the ford=yes can be tagged on the way inside the riverbanks, in which case the shared node will still exist, but not have the ford=yes tag itself.

This sentence is not understandable. When you tag a ford you have a ford.

Currently JOSM warns even when a riverbank is crossed. This case should throw no warning.

[aceman]

I say there is a difference when the ford=yes is on a common node and when it is on a way, that shares a node with the waterway, but should not have the ford=yes tag.

[skyper]

some virtual examples

[skyper]

Ok, for railway=* this should always be a warning. There are no fords for railways, are there?
For highway=* there is a similar problem as the railway crossings in #17074. What to do with end nodes of highways and touching or multiple highways connected from only one side?
I made up some examples: josm_18375_ford_examples.osm​