Fixing ActorPoolSpec (more specifically the ActiveActorsPressure thingie-device) and stopping the typed actors after the test of the spec

akka-actor-tests/src/test/scala/akka/routing/ActorPoolSpec.scala

@@ -351,6 +351,7 @@ class ActorPoolSpec extends AkkaSpec {
         val value = r.get
         value must equal(i * i)
       }
+      app.typedActor.stop(pool)
     }
 
     "provide default supervision of pooled actors" in {

akka-actor/src/main/scala/akka/routing/Pool.scala

@@ -296,8 +296,10 @@ trait MailboxPressureCapacitor {
 trait ActiveActorsPressureCapacitor {
   def pressure(delegates: Seq[ActorRef]): Int =
     delegates count {
-      case a: LocalActorRef ⇒ !a.underlying.sender.isShutdown
-      case _                ⇒ false
+      case a: LocalActorRef ⇒
+        val cell = a.underlying
+        cell.mailbox.isScheduled && cell.currentMessage != null
+      case _ ⇒ false
     }
 }