Merge pull request #309 from dotty-staging/fix/#306-avoidance-problem

Avpid returning ExprTypes from blocks.

Author: DarkDimius

src/dotty/tools/dotc/typer/TypeAssigner.scala

@@ -43,7 +43,7 @@ trait TypeAssigner {
       }
       def apply(tp: Type) = tp match {
         case tp: TermRef if toAvoid(tp) && variance > 0 =>
-          apply(tp.info)
+          apply(tp.info.widenExpr)
         case tp: TypeRef if (forbidden contains tp.symbol) || toAvoid(tp.prefix) =>
           tp.info match {
             case TypeAlias(ref) =>

tests/pos/i0306.scala

@@ -0,0 +1,17 @@
+object bar {
+
+  class C[T <: Seq[_]]
+
+  val x: AnyRef = new C
+
+  val y = x match {
+    case x: C[u] =>
+      def xx: u = xx
+      xx
+  }
+
+  val z= {
+    def xx: String = xx
+    xx
+  }
+}