[jdev] is [ever empty] text element mandatory in error staza?

[Alexey Nezhdanov]

XMPP-Core says:

For stream errors:
<stream:error>
  <defined-condition xmlns='urn:ietf:params:xml:ns:xmpp-streams'/>
  <text xmlns='urn:ietf:params:xml:ns:xmpp-streams'>
    OPTIONAL descriptive text
  </text>
  [OPTIONAL application-specific condition element]
</stream:error>

For stanza errors:

<stanza-name to='sender' type='error'>
  [RECOMMENDED to include sender XML here]
  <error type='error-type'>
    <defined-condition xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
    <text xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>
      OPTIONAL descriptive text
    </text>
    [OPTIONAL application-specific condition element]
  </error>
</stanza-name>

In the meantime
ejabberd does not include <text/> node into it's reply:
<?xml version='1.0'?><stream:stream xmlns='jabber:client' 
xmlns:stream='http://etherx.jabber.org/streams' id='none' 
from='jabber.ru' version='1.0'><stream:error><xml-not-well-formed 
xmlns='urn:ietf:params:xml:ns:xmpp-streams'/></stream:error></stream:stream>
jabberd2 includes with descriptive text:
<stream:stream xmlns:stream='http://etherx.jabber.org/streams' 
version='1.0'><stream:error 
xmlns:stream='http://etherx.jabber.org/streams'><xml-not-well-formed 
xmlns='urn:ietf:params:xml:ns:xmpp-streams'/><text 
xmlns='urn:ietf:params:xml:ns:xmpp-streams'>syntax 
error</text></stream:error></stream:stream>

JEP-0047 (http://www.jabber.org/jeps/jep-0047.html) does not include 
<text/> element in the reply:

<iq type='error' 
    from='juliet at capulet.com/balcony'
    to='romeo at montague.net/orchard'
    id='inband_1'/>
  <error code='501' type='cancel'>
    <feature-not-implemented xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
  </error>
</iq>

======
Hence, the question:
is <text/> node mandatory child of <error/> stanza ever it no text is 
provided?

--
Respectfully
Alexey Nezhdanov