VB -> C#: wrong modifier for optional out parameter

[KunzeAndreas]

VB.Net input code

Private Shared Sub OutParameterModifier()
    Dim a As Integer
    Dim b As Integer
    WithOutParam(a:=a, b:=b)
    Assert.That(a = 42)
    Assert.That(b = 23)

    WithOutParam(a:=a)
    Assert.That(a = 42)
End Sub

Private Shared Sub WithOutParam(<Out> ByRef a As Integer, <Out> Optional ByRef b As Integer = Nothing)
    a = 42
    b = 23
End Sub

Erroneous output

 private static void OutParameterModifier()
  {
      int a;
      int b;
      WithOutParam(a: out a, b: out b);
      Assert.That(a == 42);
      Assert.That(b == 23);

      int argb = 0;
      VbConverterTests.WithOutParam(a: out a, b: ref argb);
      Assert.That(a == 42);
  }

  private static void WithOutParam(out int a, [Optional, DefaultParameterValue(default(int))] out int b)
  {
      a = 42;
      b = 23;
  }

Expected output

 VbConverterTests.WithOutParam(a: out a, b: out argb);

Details

• Product in use: VS extension
• Version in use: 8.5.0.0
• Did you see it working in a previous version, which? no