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​

[aceman]

Ends of highways? Like highway extending only to the waterway in the middle of the river? Are there such case? Are those slipways or something? Shouldn't they mostly end at the riwerbank?

[skyper]

Yes, slipway might be a reason for an highway ending at the waterway. Another one might be that the highway ends at the opposite riverbank and the last part (waterway -> opposite riverbank) was forgotten.