IT31623: MQ classes for JMS incorrectly treat messages with headers that have a CCSID field set to -2 as poison messages.

APAR status

• Closed as program error.

Error description

• A message that contains an MQHRF Version 1 header is put to a
  queue. The header is the last header before the message payload,
  and has the "CodedCharSetID" (CCSID) field set to the value -2,
  as shown below:
  
  ------------------------------------------------------------
  MQMD:
      - Version 2
      - PutApplType: 26 (MQAT_BROKER)
      - CCSID: 1208
      - Encoding: 546
      - Format: MQHRF
  MQHRF
      - Version: 1
      - CCSID: -2
      - Encoding: 546
      - Format: MQSTR
  Message Payload
  ------------------------------------------------------------
  
  An IBM MQ classes for JMS application:
  
  - Creates a JMSContext to establish a connection to the queue
  manager where the queue is located.
  - Creates a JMSConsumer for the queue hosting the message.
  - Calls the method JMSConsumer.receiveBody(Class<T> c, long
  timeout) to get the message.
  
  However, rather than being returned to the application, the IBM
  MQ classes for JMS move the message to the queue manager's dead
  letter queue.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of the IBM MQ classes for JMS who have
  applications that consume messages from a JMS destination,
  where:
  
  - The messages contain one or more headers.
  - And the last header before the message payload has the
  "CodedCharSetID" (CCSID) field set to MQCCSI_INHERIT (-2)
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  IBM MQ messages have the following format:
  
  - An MQ Message Descriptor (MQMD)
  - Zero or more message headers.
  - The message payload.
  
  The MQMD, and the message headers, contain a field called
  "CodedCharSetID" (CCSID). This field specifies the character set
  identifier of the character data in the next part of the message
  (which is either a header or the message payload). If the CCSID
  field within a message header is set to MQCCSI_INHERIT (-2),
  then it indicates that the character data in the next part of
  the message (either another header or the message payload) is
  encoded using the same CCSID as this header.
  
  For example, in the following message, the character data in the
  message payload is encoded using CCSID 1208:
  
  ------------------------------------------------------------
  MQMD:
      - Version 2
      - PutApplType: 26 (MQAT_BROKER)
      - CCSID: 1208
      - Encoding: 546
      - Format: MQHRF
  MQHRF
      - Version: 1
      - CCSID: -2
      - Encoding: 546
      - Format: MQSTR
  Message Payload
  ------------------------------------------------------------
  
  
  Now, when the IBM MQ classes for JMS received a message from a
  destination, they would process all of the headers on that
  message first before processing the message body. If they
  detected that the last header on a message had the CCSID field
  set to MQCCSI_INHERIT, then they would incorrectly assume that
  the character data within the message body was encoded using
  CCSID -2. As a result, the IBM MQ classes for JMS would try to
  use CCSID -2 to decode the character data in the message body -
  this would fail as -2 did not map to a character set.
  
  Because of this, the IBM MQ classes for JMS would determine that
  the message was a "poison message", and either:
  
  - Move it to a backout requeue queue (if one was specified)
  - Put it to the queue manager's dead letter queue.
  - Or discard it.
  
  depending on how the queue manager had been configured, the
  design of the application and report options of the message.
  

Problem conclusion

• The IBM MQ classes for JMS have been updated to correctly handle
  messages where the last header before the message payload has
  the "CodedCharSetID" (CCSID) field set to the value
  MQCCSI_INHERIT (-2). This ensures that the CCSID of the header
  before the last one is used to decode the character data in the
  message payload, which allows the message to be returned to the
  application.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.1 CD    9.1.5
  v9.1 LTS   9.1.0.5
  
  The latest available maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  IBM MQ BASE MP

• Fixed component ID

  5724H7271

Applicable component levels