Compute PureInterface flag after pickling.

ElimLocals becomes a slightly less trivial transform: NormalizeFlags.
It also computes PureInterface flag, thus relieving Namer and Unpickler
from doing the same in two different ways. Besides, the computation in
Namer/TreeInfo was flawed because it did not take into account that
nested non-static classes are not allowed in an interface (only static
classes are, but these would not be members of the interface in the Scala
sense).

1 files changed, 45 insertions, 0 deletions

diff --git a/tests/pos/pickleOK/i94-nada.scala b/tests/pos/pickleOK/i94-nada.scala
new file mode 100644
index 000000000..ce8dc98ad
--- /dev/null
+++ b/tests/pos/pickleOK/i94-nada.scala
@@ -0,0 +1,45 @@
+package i94
+
+import scala.language.higherKinds
+
+trait Base {
+  type Rep[T]
+}
+
+trait BaseExp extends Base {
+  type Rep[T] = Exp[T]
+  case class Exp[T](v: T)
+}
+
+trait BaseStr extends Base {
+  type Rep[T] = String
+}
+
+trait BaseDirect extends Base {
+  type Rep[T] = T
+}
+
+trait Test1 {
+  trait Monad[X] {
+    def x: X
+  }
+  sealed abstract class Either[A,B]
+  case class Left[A,B](x: A) extends Either[A,B] with Monad[A]
+  case class Right[A,B](x: B) extends Either[A,B] with Monad[B]
+  def flatMap[X,Y,M[X]<:Monad[X]](m: M[X], f: X => M[Y]): M[Y] = f(m.x)
+  println(flatMap(Left(1), {x: Int => Left(x)}))
+}
+trait Test2 {
+  trait Monad[X] {
+    def x: X
+  }
+  sealed abstract class Either[A,B]
+  case class Left[A,B](x: A) extends Either[A,B] with Monad[A]
+  case class Right[A,B](x: B) extends Either[A,B] with Monad[B]
+  def flatMap[X,Y,M[X]](m: M[X], f: X => M[Y]): M[Y]
+  println(flatMap(Left(1), {x: Int => Left(x)}))
+}
+trait Test3 {
+  def flatMap[X,Y,M[X]](m: M[X], f: X => M[Y]): M[Y]
+  println(flatMap(Some(1), {x: Int => Some(x)}))
+}