1 files changed, 15 insertions, 0 deletions
diff --git a/tests/run/t1220.scala b/tests/run/t1220.scala
new file mode 100644
index 000000000..3f70107ce
--- /dev/null
+++ b/tests/run/t1220.scala
@@ -0,0 +1,15 @@
+object Test extends dotty.runtime.LegacyApp {
+
+  class QSRichIterable[A](self: Iterable[A]) {
+    def filterMap[R](f: PartialFunction[A,R]) =
+      self filter (f.isDefinedAt) map f
+  }
+
+  object Un {
+    def unapply(i: Int): Option[Int] = Some(i)
+  }
+
+  val richIter = new QSRichIterable(List(0, 1, 2, 3, 4))
+
+  assert((richIter filterMap {case Un(3) => 7}) == List(7))
+}