From 74dc99a656e7e329245d5e04ca10fa27d6bb3920 Mon Sep 17 00:00:00 2001
From: Alexander Golubev <alexander.golubev@gmail.com>
Date: Thu, 24 Sep 2015 22:25:06 -0400
Subject: [PATCH] +str #18486 Make sure that Source.subscriber's Subscriber
 throws if subscribed more than once

---
 .../src/main/scala/akka/stream/impl/StreamLayout.scala        | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/akka-stream/src/main/scala/akka/stream/impl/StreamLayout.scala b/akka-stream/src/main/scala/akka/stream/impl/StreamLayout.scala
index 59dbc6a62d..b00b4b0a8f 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/StreamLayout.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/StreamLayout.scala
@@ -379,11 +379,9 @@ private[stream] final class VirtualProcessor[T] extends Processor[T, T] {
               case Completed  ⇒ tryOnComplete(s)
               case Failed(ex) ⇒ tryOnError(s, ex)
               case Allowed    ⇒ // all good
-
             }
           } catch {
-            case ex @ canNotSubscribeTheSameSubscriberMultipleTimesException ⇒ throw ex
-            case NonFatal(ex) ⇒ sub.cancel()
+            case NonFatal(ex) ⇒ if (isCancelled) throw ex else sub.cancel()
           }
       }
   }