1 files changed, 17 insertions, 0 deletions
diff --git a/test/pending/neg/t6680c.scala b/test/pending/neg/t6680c.scala
new file mode 100644
index 0000000000..f69663a71b
--- /dev/null
+++ b/test/pending/neg/t6680c.scala
@@ -0,0 +1,17 @@
+package s
+
+trait Stream[+A]
+case class Unfold[S,+A](s: S, f: S => Option[(A,S)]) extends Stream[A]
+
+object Stream {
+  def fromList[A](a: List[A]): Stream[A] =
+    Unfold(a, (l:List[A]) => l.headOption.map((_,l.tail)))
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val res = Stream.fromList(List(1,2,3,4))
+
+    res match { case Unfold(s, f) => f("a string!") }
+  }
+}