MethodInfo.CreateDelegate() creates working delegate but delegate.Method throws

[atykhyy]

Description

When invoked on a method of a generic value type to create an open delegate, MethodInfo.CreateDelegate() creates a working delegate (i.e. the delegate can be invoked given suitable arguments) but the delegate's Method property throws an exception complaining about incompatible type and method handles. This behavior does not occur if the value type is not generic or if the generic type is a reference type and normal Action<> is used in place of RefAction<>. The code snippet below illustrates the problem.

Reproduction Steps

void Main()
{
	var d2 = CreateMyDelegate (typeof (D)) ; // ok
	var x2 = new D () ;
	((RefAction<D>) d2).Invoke (ref x2) ; // ok
	d2.Method.ToString() ; // ok

	var d3 = CreateMyDelegate (typeof (E<int>)) ; // ok
	((Action<E<int>>) d3).Invoke (new E<int> ()) ; // ok
	d3.Method.ToString() ; // ok

	var d1 = CreateMyDelegate (typeof (C<int>)) ; // ok
	var x1 = new C<int> () ;
	((RefAction<C<int>>) d1).Invoke (ref x1) ; // ok
	d1.Method.ToString() ; // .Method throws
}

static Delegate CreateMyDelegate (Type t)
{
	var m = t.GetMethod ("Foo") ;
	return m.CreateDelegate ((t.IsValueType ? typeof (RefAction<>) : typeof (Action<>)).MakeGenericType (t)) ;
}

delegate void RefAction<T> (ref T t) where T : struct ;

struct C<T> { public void Foo () {} }
struct D    { public void Foo () {} }
class  E<T> { public void Foo () {} }

Expected behavior

d1.Method returns the method used to create the open delegate.

Actual behavior

d1.Method throws an exception despite the open delegate being created successfully.

Regression?

No response

Known Workarounds

I have to pass the MethodInfo used to create the delegate around with the delegate since I can't rely on the delegate's Method property.

Configuration

Runtime: Microsoft.NETCore.App 8.0.6 [windows] (probably irrelevant)

Other information

No response

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[steveharter]

This looks like a duplicate of #108619.