Re: XMLATTRIBUTES vs. values of type XML

On tis, 2011-07-26 at 22:44 +0200, Florian Pflug wrote:
> While reviewing the (now applied) XPATH escaping patches, Radoslaw
> found one
> case where the previous failure of XPATH to escape its return value
> was offset
> by XMLATTRIBUTES insistence to escape all input values, even if
> they're
> already of type XML.
> 
> To wit, if you do
> 
>   SELECT XMLELEMENT(NAME "t", XMLATTRIBUTES('&'::XML AS "a"))
> 
> you get
> 
>      xmlelement     
> --------------------
>  <t a="&amp;"/> 

Per SQL standard, the attribute values may not be of type XML, so maybe
we should just prohibit it.