WMS: It is not appropriate to use the first CRS as default SC when multiple CRSs provided

[gregboone]

When a WMS layer is available in several coordinate reference systems, the first one listed in the capability document has been used as the default spatial context for that layer. However, there is no solid reason to support that. A more appropriate way to deal with such situation is trying to use the most universal one, or non-distortion one, e.g., geographic coordinate systems is preferable to projected CRS.

Here is an example, ​http://www.datadoors.net/$_streaminguid.258b2328-80bc-426a-a0a1-fc2023dbb333/wms.ashx?

All layers served in this server are available in many CRSs and EPSG:4267(LL27) is listed first. As a result, LL27 is the default spatial context for all layers. However, when layers are requested via LL27, the areas outside NA can't be rendered properly by the server. When switching to another available CRS EPSG:4326 (LL84), all the layers will work properly.

Since we don't allow specifying CRS for layers via UI in both Map and MapGuide, choosing a more appropriate CRS for a layer becomes more important for rendering a layer properly.