1 files changed, 9 insertions, 0 deletions
diff --git a/test/pending/pos/treecheckers/c4.scala b/test/pending/pos/treecheckers/c4.scala
new file mode 100644
index 0000000000..2328131770
--- /dev/null
+++ b/test/pending/pos/treecheckers/c4.scala
@@ -0,0 +1,9 @@
+sealed trait Message[+A]
+class Script[A] extends Message[A] {
+  def iterator: Iterator[Message[A]] = ???
+}
+
+trait Test4[A] {
+  def f(cmd: Message[A]): Iterator[A] = cmd match { case s: Script[t] => s.iterator flatMap f }
+  def g(cmd: Message[A]) = cmd match { case s: Script[t] => s }
+}