[FLINK-6162]Fix bug in ByteArrayOutputStreamWithPos#setPosition

flink-core/src/main/java/org/apache/flink/core/memory/ByteArrayOutputStreamWithPos.java

@@ -110,7 +110,7 @@ public int getPosition() {
 	}
 
 	public void setPosition(int position) {
-		Preconditions.checkArgument(position < getEndPosition(), "Position out of bounds.");
+		Preconditions.checkArgument(position <= getEndPosition(), "Position out of bounds.");
 		count = position;
 	}
 

flink-core/src/test/java/org/apache/flink/core/memory/ByteArrayOutputStreamWithPosTest.java

@@ -0,0 +1,31 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.core.memory;
+
+import org.junit.Test;
+
+public class ByteArrayOutputStreamWithPosTest {
+	@Test
+	public void setPositionWhenBufferIsFull() throws Exception {
+		ByteArrayOutputStreamWithPos stream = new ByteArrayOutputStreamWithPos();
+		stream.write(new byte[64]);
+		stream.setPosition(stream.getPosition());
+	}
+
+}