1 files changed, 15 insertions, 0 deletions
diff --git a/tests/pos/t6084.scala b/tests/pos/t6084.scala
new file mode 100644
index 000000000..1aa1fed39
--- /dev/null
+++ b/tests/pos/t6084.scala
@@ -0,0 +1,15 @@
+package object foo { type X[T, U] = (T => U) }
+
+package foo {
+  abstract class Foo[T, U](val d: T => U) extends (T => U) {
+    def f1(r: X[T, U])           = r match { case x: Foo[_,_] => x.d }  // inferred ok
+    def f2(r: X[T, U]): (T => U) = r match { case x: Foo[_,_] => x.d }  // dealiased ok
+    def f3(r: X[T, U]): X[T, U]  = r match { case x: Foo[_,_] => x.d }  // alias not ok
+
+    // x.d : foo.this.package.type.X[?scala.reflect.internal.Types$NoPrefix$?.T, ?scala.reflect.internal.Types$NoPrefix$?.U] ~>scala.this.Function1[?scala.reflect.internal.Types$NoPrefix$?.T, ?scala.reflect.internal.Types$NoPrefix$?.U]
+    //  at scala.Predef$.assert(Predef.scala:170)
+    //  at scala.tools.nsc.Global.assert(Global.scala:235)
+    //  at scala.tools.nsc.ast.TreeGen.mkCast(TreeGen.scala:252)
+    //  at scala.tools.nsc.typechecker.Typers$Typer.typedCase(Typers.scala:2263)
+  }
+}