12.7.5 and 12.18.2 Member access evaluation order for assignments

[gafter]

This is a companion issue to #169

12.7.5 (member access) suggests that evaluating a member access expression performs a nullity check.

12.18.2 (simple assignment) states for an assignment x = y:

• If x is classified as a variable:
  • x is evaluated to produce the variable.
  • y is evaluated and, if required, converted to the type of x through an implicit conversion (§12.2).

That all sounds fine, but my understanding of reality is that the nullity check is only performed after y is evaluated. Sample code to show that...

public class Q {
    public int x;

    public static void Main() {
        Q q = null;
        q.x = SideEffect();
    }
    
    public static int SideEffect()
    {
        System.Console.WriteLine("SideEffect");
        return 2;
    }
}

Assigning to Mads initially as he has been assigned #169