Hamburg, Germany – weird double entry with different data

[MrMooky]

When searching for Hamburg these two suggestions pop up in germany:

They both are named the same, but result in different lat lng coordinates. The first is correct, the second one lands somewhere in a field near Hamburg, but that part does not belong to Hamburg:

Is this something I can fix, or is it a bug?

[JonathanMontane]

@MrMooky Thanks for the report.

The issue here is that the shape for Hamburg in OSM looks like this:

And our processing system is not behaving perfectly with multi-polygonal disjoint shapes, as it creates a single centroid for the whole shape (which happens to be problematic here because of the distance between the two shapes), and because this point is too far from the other data points that we have about Hamburg, we fail to merge them together, leading to two separate Hamburg records.

We are currently exploring ideas that would allow us to solve this type of issue, and will keep you updated when we have an acceptable fix.