PM75876: THE "HEADER" DIRECTIVE CAN'T SET A HEADER ONLY IF THE HEADER IS ABSENT, EVEN WHEN USING "EDIT" MODE OR RELYING ON OTHER MODULES.

8.5.0.2: WebSphere Application Server V8.5 Fix Pack 2
8.0.0.6: WebSphere Application Server V8.0 Fix Pack 6

APAR status

• Closed as program error.

Error description

• Customers often want to set header X if and only if header X is
  not already present, but there is no indirect way to achieve
  this with mod_headers.  There is an "edit" supported, but it
  cannot be safely made to allow the empty match (^$) to be
  acted upon in the service stream.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  Users of IBM HTTP Server                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: No combination of standard modules can  *
  *                      set a response header if and only if    *
  *                      that response header is not yet         *
  *                      present.                                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  "Header edit", nor any combination of other directives, can't
  set
  a response header if and only if that header is not yet
  present.
  

Problem conclusion

• PM75876 provides a supported way to express this operation with
  "Header SetIfempty HEADERNAME VALUE".
  
  This fix is targeted for IHS fixpacks:
   - 7.0.0.29
   - 8.0.0.6
   - 8.5.0.2
  

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 HTTP SERVER

• Fixed component ID

  5724J0801

Applicable component levels

• R700 PSY

     UP

• R800 PSY

     UP

• R850 PSY

     UP