[QPID-6653] Earlier Qpid Java client: receiver issue with multi-transfer pre-settled messages

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.32
• Fix Version/s: qpid-java-broker-7.0.0
• Component/s: Broker-J
• Assignee: Unassigned
• Reporter: Xin Chen
• Created: 23/Jul/15 20:48
• Updated: 03/Aug/17 19:47
• Resolved: 03/Aug/17 19:47

Description

This issue is regarding the Qpid Java client released as part of the Qpid JMS 0.32. https://qpid.apache.org/releases/qpid-0.32/index.html

When the remote peer sends settled message with multiple transfer frames, it could use the same delivery tag (e.g. an empty binary) for all messages. The ReceivingLinkEndpoint class keeps track of both unsettled deliveries and partially received deliveries in two maps, _unsettledIds and _unsettledMap. When user acknowledges a message by calling Receiver.acknowledge(Message), the state of the delivery is removed from both maps. This is causing a problem if the user acknowledges a previously received message and a new message is being partially received (because they share the same delivery tag). The observed symptom is receiver stuck and NullPointerException from connection's frame pump when decoding frame buffers.

I attempted a fix by using a new variable to remember the last received partial delivery, if any, and only putting unsettled deliveries into the two maps. It worked in this particular scenario. The existing tests are passing with this change but I am not completely sure if it has any side effects.

I will attach a modified ReceivingLinkEndpoint.Java file so you can take a look.