Test case closes SI-5137.

virtpatmat strikes again.

Author: retronym

test/files/pos/t5137.scala

@@ -0,0 +1,17 @@
+object Test {
+
+  // okay
+  (1 * (List[BigInt]().map(((x0) => x0 match {
+    case x => x
+  })).sum))
+
+  // okay
+  ((1: BigInt) * (List[BigInt]().map({
+    case x => x
+  }).sum))
+
+  // fail
+  (1 * (List[BigInt]().map({
+    case x => x
+  }).sum))
+}