fixed issue in rollback if the buffers that where given are in use

Author: lwahlmeier

src/main/java/org/threadly/litesockets/buffers/TransactionalByteBuffers.java

@@ -135,7 +135,7 @@ public int get(final byte[] destBytes) {
   public ByteBuffer pullBuffer(final int size) {
     if(lock.isLocked()) {
       if(lock.isHeldByCurrentThread()) {
-        final ByteBuffer bb = super.pullBuffer(size);
+        final ByteBuffer bb = super.pullBuffer(size).duplicate();
         consumedSinceBegin+=size;
         return bb;
       } else {

src/test/java/org/threadly/litesockets/buffers/TransactionalByteBuffersTests.java

@@ -4,6 +4,7 @@
 import static org.junit.Assert.assertTrue;
 
 import java.nio.ByteBuffer;
+import java.util.ArrayList;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.junit.After;
@@ -62,6 +63,27 @@ public boolean get() {
     }
   }
 
+
+  @Test
+  public void rollBackWithBuffersActive() {
+    int bufferSize = 1000000;
+    TransactionalByteBuffers tbb = new TransactionalByteBuffers();
+    tbb.add(ByteBuffer.allocate(bufferSize));
+    ArrayList<ByteBuffer> lbb =new ArrayList<>();
+    tbb.begin();
+    while(tbb.hasRemaining()) {
+      lbb.add(tbb.pullBuffer(Math.min(100, tbb.remaining())));
+    }
+    tbb.rollback();
+    int countSize = 0;
+    for (ByteBuffer bb : lbb) {
+      countSize+=bb.remaining(); 
+    }
+    assertEquals(bufferSize, countSize);
+    assertEquals(bufferSize, tbb.remaining());
+    
+  }
+  
   @Test
   public void getArrayTest() {
     String s = "TEST1234567890";