Wrong overload resolution

[rumbu via Digitalmars-d-learn]

This problem appears only if one of the parameters is an 
interface. Without it or using any other type as a second 
parameter instead of the interface, it compiles. Also it compiles 
if the passed interface is null. The example below uses 
short/ushort, but I found the same behaviour for any combination 
of integral types of the same bitsize (byte/ubyte/char, 
ushort/short/wchar, int/uint/dchar, long/ulong)

D 2.066.1

interface I {}
class C: I {}

void func(ushort s, I i)
{
     writeln("ushort overload");
}

void func(short s, I i)
{
     writeln("short overload");
}

void call(short s)
{
     C c = new C();
     I d = new C();
     func(s, c); // ---- ERROR ---- see below

     //but these are ok

     func(s, cast(I)c) //ok
     func(s, d) //ok
     func(s, null) //ok

}

main.func called with argument types (short, C) matches both:	
main.func(short s, I i)	
main.func(ushort s, I i)