INT-4374: TCP Fix elastic raw deserializer

JIRA: https://jira.spring.io/browse/INT-4374

Detect end of stream to prevent emitting an empty byte[] payload.

Author: garyrussell

spring-integration-ip/src/main/java/org/springframework/integration/ip/tcp/serializer/ByteArrayElasticRawDeserializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -56,7 +56,9 @@ public ByteArrayElasticRawDeserializer(int initialBufferSize) {
 	@Override
 	public byte[] deserialize(InputStream inputStream) throws IOException {
 		ByteArrayOutputStream out = new ByteArrayOutputStream(this.initialBufferSize);
-		StreamUtils.copy(inputStream, out);
+		if (StreamUtils.copy(inputStream, out) == 0) {
+			throw new SoftEndOfStreamException("Stream closed with no data");
+		}
 		out.close();
 		return out.toByteArray();
 	}

spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/serializer/DeserializationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -153,6 +153,13 @@ public void testReadRawElastic() throws Exception {
 		byte[] out = serializer.deserialize(socket.getInputStream());
 		assertEquals("Data", SocketTestUtils.TEST_STRING + SocketTestUtils.TEST_STRING,
 				new String(out));
+		try {
+			serializer.deserialize(socket.getInputStream());
+			fail("Expected end of Stream");
+		}
+		catch (SoftEndOfStreamException e) {
+			// NOSONAR
+		}
 		server.close();
 	}