Oliver Tonnhofer

> Mapnik 3 in general allows variable substitutions everywhere In this context *variables* are values from an SQL query, etc. > In particular, as part of zoom filters: > [feature...

`group-by` is working, but there will be likely a few other obstacles. Right now, I wouldn't recommend it either as I don't have time to help out.

This change is backwards incompatible and will break existing configurations. Please [check my comment here](https://github.com/mapproxy/mapproxy/issues/293#issuecomment-302040107).

That's the thing with backwards compatibility: It works for you but not for existing installations. I know of client configurations that will fail with this patch. I'm no longer active...

> @olt I get it! I will add tests. By the way, can you provide some configurations that will fail with this patch? In order to improve the test and...

The TMS specification defines that a webmercator tilegrid starts with four tiles (https://wiki.osgeo.org/wiki/Tile_Map_Service_Specification#global-mercator) Please use ``/tiles`` instead of ``/tms`` to get the desired behavior. (See: https://mapproxy.org/docs/nightly/services.html#openlayers)

Yes, the capabilities could use the coverage for BoundingBox, as long as Offset is right.

Can you check if 3ea79303 fixes this?

See "Nightly" on https://mapproxy.org/download

I did noticed that as well while I wanted to remove more old-style multipolygon code from Imposm. There are a lot of relations where the outer way contains the same...