=str #24934 sub timeout must be cancelled when streams establish conn

akka-stream/src/main/scala/akka/stream/impl/streamref/SourceRefImpl.scala

@@ -93,13 +93,10 @@ private[stream] final class SourceRefStageImpl[Out](
 
         promise.success(SinkRefImpl(self.ref))
 
-        partnerRef match {
-          case OptionVal.None ⇒
-            // only schedule timeout timer if partnerRef has not been resolved yet (i.e. if this instance of an Actor
-            // has not been provided with a valid initial partnerRef
-            scheduleOnce(SubscriptionTimeoutTimerKey, subscriptionTimeout.timeout) // nothing to do
-          case _ ⇒
-        }
+        //this timer will be cancelled if we receive the handshake from the remote SinkRef
+        // either created in this method and provided as self.ref as initialPartnerRef
+        // or as the response to first CumulativeDemand request sent to remote SinkRef
+        scheduleOnce(SubscriptionTimeoutTimerKey, subscriptionTimeout.timeout)
       }
 
       override def onPull(): Unit = {
@@ -132,7 +129,7 @@ private[stream] final class SourceRefStageImpl[Out](
         case SubscriptionTimeoutTimerKey ⇒
           val ex = StreamRefSubscriptionTimeoutException(
             // we know the future has been competed by now, since it is in preStart
-            s"[$stageActorName] Remote side did not subscribe (materialize) handed out Source reference [${promise.future.value}]," +
+            s"[$stageActorName] Remote side did not subscribe (materialize) handed out Sink reference [${promise.future.value}]," +
               s"within subscription timeout: ${PrettyDuration.format(subscriptionTimeout.timeout)}!")
 
           throw ex // this will also log the exception, unlike failStage; this should fail rarely, but would be good to have it "loud"