GetXmlDocsSummary fails on methods with Expression parameters whose delegate returns a generic type

[Chris Cason]

Using .NET 4.8 with Namotion.Reflection v2.0.3, if I have a method with a signature like the following:

public void TestMethod(Expression<Func<TModel>> expr)

and then call GetXMLDocsSummary() on a MethodInfo instance for it, the call will return an empty string even when there is an appropriate entry in the XML doc file. However if I change the return of the delegate to a concrete type (e.g. Func<string>>) the summary is returned without issue.

Stepping into the code I can see that GetMemberElementName() is throwing a "Method may only be called on a Type for which Type.IsGenericParameter is true." exception. This occurs at the point where the code iterates the generic type arguments and references GenericParameterPosition. The type in question (the Func) has IsGenericParameter as false (however its GenericTypeArguments has a member with IsGenericParameter true and a valid GenericParameterPosition - perhaps an additional level of indirection is needed?)

Test case code (based on the Namotion.Reflection.Demo sample) is attached.

Program.cs.txt