[QGIS-Developer] QGIS Server 3: change on queryable groups?

[Gerald Kogler]

Hi devs,

I recently migrated from QGIS Server 2 to 3 (a big thanks to all the
devs!) and I noticed one change with queryable parameters which means
quite a lot of work to migrate my projects:

In QGIS Server 2 layer groups had the "queryable" parameter showing up
on GetCapabilities request. That makes it easy to apply GetFeatureInfo
to the group without iterating over all its layers.

In QGIS Server 3 layer groups don't have the "queryable" parameter. So I
need to call GetFeatureInfo on all its layers but not on the layer group.

Is there any reason for this change or any configuration I missed?

I think the queryable parameter makes sense and is compatible with the
OCG WMS sepecification, which states:

"7.2.4.7.2 Queryable layers:
The Boolean attribute queryable indicates whether the server supports
the GetFeatureInfo operation on that Layer. A server may support
GetFeatureInfo on some of its layers, but need not support it on all
layers."

Thanks for everything
Gerald