Subject: [xmpp] [Technical Errata Reported] RFC6120 (4228)

From: RFC Errata System <[email-masked]>
Date: Sat, 10 Jan 2015 11:31:21 -0800 (PST)

The following errata report has been submitted for RFC6120,
"Extensible Messaging and Presence Protocol (XMPP): Core".

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You may review the report below and at:
http://www.rfc-editor.org/errata_search.php?rfc=6120&eid=4228

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Type: Technical
Reported by: Georg Sauthoff <[email-masked]>

Section: A.6.

Original Text
-------------
     <xs:element name='subject'>
       <xs:complexType>
         <xs:simpleContent>
           <xs:extension base='xs:string'>
             <xs:attribute ref='xml:lang' use='optional'/>
           </xs:extension>
         </xs:simpleContent>
       </xs:complexType>
     </xs:element>

     <xs:element name='thread'>
       <xs:complexType>
         <xs:simpleContent>
           <xs:extension base='xs:NMTOKEN'>
             <xs:attribute name='parent'
                           type='xs:NMTOKEN'
                           use='optional'/>
           </xs:extension>
         </xs:simpleContent>
       </xs:complexType>
     </xs:element>

Saint-Andre                  Standards Track                  [Page 202]

RFC 6120                        XMPP Core                     March 2011

     <xs:element name='subject'>
       <xs:complexType>
         <xs:simpleContent>
           <xs:extension base='xs:NMTOKEN'>
             <xs:attribute name='parent'
                           type='xs:NMTOKEN'
                           use='optional'/>
           </xs:extension>
         </xs:simpleContent>
       </xs:complexType>
     </xs:element>

Corrected Text
--------------
     <xs:element name='subject'>
       <xs:complexType>
         <xs:simpleContent>
           <xs:extension base='xs:string'>
             <xs:attribute ref='xml:lang' use='optional'/>
           </xs:extension>
         </xs:simpleContent>
       </xs:complexType>
     </xs:element>

     <xs:element name='thread'>
       <xs:complexType>
         <xs:simpleContent>
           <xs:extension base='xs:NMTOKEN'>
             <xs:attribute name='parent'
                           type='xs:NMTOKEN'
                           use='optional'/>
           </xs:extension>
         </xs:simpleContent>
       </xs:complexType>
     </xs:element>

Saint-Andre                  Standards Track                  [Page 202]

RFC 6120                        XMPP Core                     March 2011

Notes
-----
The issue is that the definition of the referenced element 'subject' is duplicated.

This can be easily tested via a command like:

$ xmllint --schema XMLSchema_1.1.xsd server.xsd --noout
server.xsd:84: element element: Schemas validity error : Element '{http://www.w3.org/2001/XMLSchema}element': Duplicate key-sequence ['subject'] in key identity-constraint '{http://www.w3.org/2001/XMLSchema}element'.
server.xsd fails to validate

The corrected text contains one possible edit how to make the XSD of the server namespace valid again. Of course, another possibility would be to remove the first definition of the 'subject' element.

I've eliminated the second definition because the first one equals the one from section A.5. (Client Namespace).

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RFC6120 (draft-ietf-xmpp-3920bis-22)
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Title               : Extensible Messaging and Presence Protocol (XMPP): Core
Publication Date    : March 2011
Author(s)           : P. Saint-Andre
Category            : PROPOSED STANDARD
Source              : Extensible Messaging and Presence Protocol
Area                : Real-time Applications and Infrastructure
Stream              : IETF
Verifying Party     : IESG