Incorrect type inference when error occurred

[VladD2]

variant Test
{
  | Foo
  | Bar
}

module Program
{
  Main() : void
  {
    def fn(val : Test)
    {
      match (val)
      {
        | Foo => fn(null)
        | _ => val // E: can't cast Test to Test.Foo (incorrect)
      }
    }
    _ = match (fn(null))
    {
      | Test.Foo => w; // Real error
      | _ => "";
    }
  }
}

[rampelstinskin]

Warning: // W: this match clause is unused
Incorrect.