=str 20843 Scan.in cannot pull closed port

akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowScanSpec.scala

@@ -64,5 +64,18 @@ class FlowScanSpec extends AkkaSpec {
       Source(List(1, 3, -1, 5, 7)).via(scan).runWith(TestSink.probe)
         .toStrict(1.second) should ===(Seq(0, 1, 4, 9, 16))
     }
+
+    "scan normally for empty source" in {
+      Source.empty[Int].scan(0) { case (a, b) ⇒ a + b }.runWith(TestSink.probe[Int])
+        .request(2)
+        .expectNext(0)
+        .expectComplete()
+    }
+    "fail after emitting first element when upsrteam failed" in {
+      Source.failed[Int](TE("")).scan(0) { case (a, b) ⇒ a + b }.runWith(TestSink.probe[Int])
+        .request(2)
+        .expectNext(0)
+        .expectError(TE(""))
+    }
   }
 }

akka-stream/src/main/scala/akka/stream/impl/fusing/Ops.scala

@@ -315,7 +315,22 @@ private[akka] final case class Scan[In, Out](zero: Out, f: (Out, In) ⇒ Out) ex
           setHandlers(in, out, self)
         }
       })
-      setHandler(in, totallyIgnorantInput)
+
+      setHandler(in, new InHandler {
+        override def onPush(): Unit = ()
+        override def onUpstreamFinish(): Unit = setHandler(out, new OutHandler {
+          override def onPull(): Unit = {
+            push(out, aggregator)
+            completeStage()
+          }
+        })
+        override def onUpstreamFailure(ex: Throwable): Unit = setHandler(out, new OutHandler {
+          override def onPull(): Unit = {
+            push(out, aggregator)
+            failStage(ex)
+          }
+        })
+      })
 
       override def onPull(): Unit = pull(in)
       override def onPush(): Unit = {