1 files changed, 17 insertions, 0 deletions
diff --git a/tests/pos/patternUnsoundness.scala b/tests/pos/patternUnsoundness.scala
new file mode 100644
index 000000000..4620f6c7d
--- /dev/null
+++ b/tests/pos/patternUnsoundness.scala
@@ -0,0 +1,17 @@
+object patternUnsoundness extends App {
+
+  class C[+T]
+
+  case class D[S](_s: S) extends C[S] {
+    var s: S = _s
+  }
+
+  val x = new D[String]("abc")
+  val y: C[Object] = x
+
+  y match {
+    case d @ D(x) => d.s = new Integer(1)
+  }
+
+  val z: String = x.s // ClassCast exception
+}