Re: BUG #16046: xpath returns CDATA tag along with the value in postgres 12

On 10/24/19 19:14, Chapman Flack wrote:
> <![CDATA[select 5 & 6 <yahoo!>]]>
> select 5 &amp; 6 &lt;yahoo!&gt;
>
> Either form of result is correct, and having it respect the form that was
> used in the input might even be delightfully smart.
>
> I haven't looked in the code just now to see if it is intentionally being
> delightfully smart, or more simplistic-and-lucky.

It appears to be probably unintentional-but-ok: libxml tags a CDATA
section differently (XML_CDATA_SECTION_NODE) than a text node
(XML_TEXT_NODE), so a CDATA node falls into the catch-all branch of

if (cur->type != XML_ATTRIBUTE_NODE && cur->type != XML_TEXT_NODE)

where it gets dumped faithfully by xmlNodeDump(), with the upshot
that the result always will be well-formed XML, and will respect whether
the input was supplied as CDATA or not. We could choose to say that's
what we meant it to do all along.

Regards,
-Chap