Hashcodes of nested case classes do not take outer into account

[odersky]

Minimized example

class A {
  case class B()
}

Output

If we compile with -Xprint:typer we get this line in the definitions of B:

      override def hashCode(): Int = scala.runtime.ScalaRunTime._hashCode(this)

The hashcode does not account for the hashcode of the outer object, even though equals does compare outer objects. This leads to bad hash functions if inner case classes are used as keys in maps.

[odersky]

Scala-2 has the same problem.