XML schema xs:string and non BMP character like 𐌀, lengthrestric

[Martin Honnen <Martin.Honnen@gmx.de>]

Hi,

I am seeing inconsistencies between different schema validating parsers 
when it comes to Unicode characters outside of the BMP, like 𐌀 
for instance, and length restrictions on xs:string.

For the sample 
http://home.arcor.de/martin.honnen/xml/oneCharInstance1.xml which has 
the contents

<?xml version="1.0" encoding="utf-8" ?>
<root>
   <test>&#x10300;</test>
</root>

the XSV validator and Saxon 9.4 EE don't report any validation errors 
when validading against the schema 
http://home.arcor.de/martin.honnen/xml/oneCharSchema1.xsd (which has as 
it contents

<?xml version="1.0" encoding="utf-8"?>
<xs:schema attributeFormDefault="unqualified" 
elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema";>
   <xs:element name="root">
     <xs:complexType>
       <xs:sequence>
         <xs:element maxOccurs="unbounded" name="test" type="one-char" />
       </xs:sequence>
     </xs:complexType>
   </xs:element>
   <xs:simpleType name="one-char">
     <xs:restriction base="xs:string">
       <xs:length value="1"/>
     </xs:restriction>
   </xs:simpleType>
</xs:schema>

).

However Xerces Java 2.11 reports "[Error] oneCharInstance1.xml:3:25: 
cvc-length-valid: Value '?' with length = '2'
  is not facet-valid with respect to length '1' for type 'one-char'." so 
it seems to consider the contents of the "test" element as a string with 
two characters.

MSXML 6 and .NET's validating parser report similar errors.

In my view Xerces and MSXML and .NET get it wrong as in terms of the XML 
specification and the schema data type &#x10300; is a single XML 
character but I would like confirmation by others on the list before 
filing bugs.



-- 

	Martin Honnen --- MVP Data Platform Development
	http://msmvps.com/blogs/martin_honnen/