JET-121 Extension closure scope, empty?

idea/testData/checker/regression/Jet121.jet

@@ -0,0 +1,14 @@
+namespace jet121 {
+  fun box() : String {
+    val answer = apply("OK") { String.() : Int =>
+      length
+      get(0)
+    }
+
+    return if (answer == 2) "OK" else "FAIL"
+  }
+
+  fun apply(arg:String, f : {String.() : Int}) : Int {
+      return arg.f()
+  }
+}