GetFeatureInfo to layers from QGIS Server needs some click tollerance

[jacobwod]

It seems like GeoServer and QGIS Server implementations of GetFeatureInfo differ in a slight way (or, it may be a setting in the WMS options that we haven't found in QGIS project files). Currently, it's almost impossible to click on a WMS layer, served from QGIS Server, and get a hit, due to (what seems to be) zero tolerance.

Fortunately, there's a custom QGIS Server option, documented here, that allows us to send 3 additional parameters that increase the click tolerance. In our case it solves the problem:

My solution will add these parameters to all feature info requests that are sent to a WMS layer where serverType==='qgis'. This will not affect any other layers.