IT33063: KC DOES NOT DOCUMENT A PERMANENT RESTRICTION IN XMLNSC VALIDATION INVOLVING UNBOUNDED WILDCARD PATTERNS

APAR status

• Closed as documentation error.

Error description

• The XMLNSC parser is not capable of correctly validating an XML
  element restricted by a pattern that includes an unbounded
  wildcard followed by a negated character class. For example
  consider the following XML schema:
  
  <?xml version="1.0" encoding="UTF-8"?>
  <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
  elementFormDefault="qualified">
      <xs:element name="StringWithXSDPattern">
          <xs:simpleType>
              <xs:restriction base="xs:string">
                  <xs:pattern value="A.*[&#94;D]"/>
              </xs:restriction>
          </xs:simpleType>
      </xs:element>
  </xs:schema>
  
  Then the input
  <StringWithXSDPattern>ADDDDDDA</StringWithXSDPattern> will fail
  validation with a cvc-pattern-valid XML schema validation error
  despite this being acceptable input. This is a permanent
  restriction of the pattern validator in the XMLNSC parser.
  Replacing the inverted character class with a non-inverted class
  will not trigger this behaviour, i.e. the pattern A.*[ABC] will
  correctly validate the same input.
  

Local fix

• Do not use .* followed by a negated character class in an XML
  schema element restriction pattern.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  All users of the XMLNSC parser in IBM Integration Bus v10 and
  IBM App Connect Enterprise v11 using patterns in schema
  validation.
  
  
  Platforms affected:
  z/OS, MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The XMLNSC parser is not capable of correctly validating an XML
  element restricted by a pattern that includes an unbounded
  wildcard followed by a negated character class. For example
  consider the following XML schema:
  
  <?xml version="1.0" encoding="UTF-8"?>
  <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
  elementFormDefault="qualified">
      <xs:element name="StringWithXSDPattern">
          <xs:simpleType>
              <xs:restriction base="xs:string">
                  <xs:pattern value="A.*[&#94;D]"/>
              </xs:restriction>
          </xs:simpleType>
      </xs:element>
  </xs:schema>
  
  Then the input
  <StringWithXSDPattern>ADDDDDDA</StringWithXSDPattern> will fail
  validation with a cvc-pattern-valid XML schema validation error
  despite this being acceptable input. This is a permanent
  restriction of the pattern validator in the XMLNSC parser.
  Replacing the inverted character class with a non-inverted class
  will not trigger this behaviour, i.e. the pattern A.*[ABC] will
  correctly validate the same input.
  

Problem conclusion

• The Knowledge Center article on XMLNSC validation now document
  this restriction.
  

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

Applicable component levels