Tuple pattern > 22 elems casts argument before calling unapply

[bishabosha]

Compiler version

3.2.0, 3.2.2-RC1-bin-20221017-b88aa12-NIGHTLY-git-b88aa12

Minimized code

(1: Any) match
  case (_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_) => ???
  case _ => println("not tuple xxl")

Output

java.lang.ClassCastException: java.lang.Integer cannot be cast to scala.runtime.TupleXXL
  ... 32 elided

Expectation

no error, output not tuple xxl

[bishabosha]

looking at further desugaring of the match, we get to the point where we desugar to the if then else form, and see that there is a cast to TupleXXL:

matchResult1[Unit]: 
{
  case val x1: Any = 1:Any
  if x1.$asInstanceOf[Object].ne(null) then 
    {
      case val x2: Option[Seq[Any]] = 
        scala.runtime.TupleXXL.unapplySeq(
          x1.$asInstanceOf[runtime.TupleXXL] // Why do we cast `Any` to `TupleXXL`?
        )
      if x2.isEmpty.unary_! then 
        {
          case val x3: Seq[Any] = x2.get
          if x3.lengthCompare(23).==(0) then 
            {
              case val x4: Any = x3.apply(0)
              case val x5: Any = x3.apply(1)
              case val x6: Any = x3.apply(2)
              case val x7: Any = x3.apply(3)
              case val x8: Any = x3.apply(4)
              case val x9: Any = x3.apply(5)
              case val x10: Any = x3.apply(6)
              case val x11: Any = x3.apply(7)
              case val x12: Any = x3.apply(8)
              case val x13: Any = x3.apply(9)
              case val x14: Any = x3.apply(10)
              case val x15: Any = x3.apply(11)
              case val x16: Any = x3.apply(12)
              case val x17: Any = x3.apply(13)
              case val x18: Any = x3.apply(14)
              case val x19: Any = x3.apply(15)
              case val x20: Any = x3.apply(16)
              case val x21: Any = x3.apply(17)
              case val x22: Any = x3.apply(18)
              case val x23: Any = x3.apply(19)
              case val x24: Any = x3.apply(20)
              case val x25: Any = x3.apply(21)
              case val x26: Any = x3.apply(22) 
              return[matchResult1] 
                {
                  ???
                }
            }
            else ()
        }
        else ()
    }
    else ()
  return[matchResult1] 
    {
      println("not tuple xxl")
    }
}