fix #4201: jetty's bytebuffers may be immediately re-used

Author: shawkins

httpclient-jetty/src/main/java/io/fabric8/kubernetes/client/jetty/JettyAsyncResponseListener.java

@@ -94,12 +94,20 @@ public void onContent(Response response, LongConsumer demand, ByteBuffer content
       this.demand.complete(demand);
     }
     try {
-      bodyConsumer.consume(process(response, content), this);
+      // we must clone as the buffer can be reused after the call to succeeded
+      bodyConsumer.consume(process(response, clone(content)), this);
       callback.succeeded();
     } catch (Exception e) {
       callback.failed(e);
     }
   }
 
   protected abstract T process(Response response, ByteBuffer content);
+
+  public static ByteBuffer clone(ByteBuffer original) {
+    ByteBuffer clone = ByteBuffer.allocate(original.remaining());
+    clone.put(original);
+    clone.flip();
+    return clone;
+  }
 }