Element constructor creates document node. It should not.

[mjhallman]

let $x := element {"root"}  {}

return $x/root() instance of document-node()

This returns true in eXist-db which is incorrect. The result of $x/root() should be an element().
I have tested this on Saxon and BaseX which both correctly return false.

[dizzzz]

please could you fill in the issue-template? It makes sure you'll add all required information, info we need to understand the exact context. thnx

[adamretter]

@dizzzz I helped @mjhallman report these. Everything that is needed to reproduce is there.

[adamretter]

It's the HEAD of the develop branch.

[adamretter]

A little investigation has shown that the problem is actually fn:root. In-memory elements in eXist-db always have an Owner Document, which they should not when directly constructed with element x {}, and so fn:root always returns the document-node() by mistake.

See the examples here: https://www.w3.org/TR/xpath-functions/#func-root-examples

The following XQUnits show the issue:

declare
    %test:assertEquals("false")
function root:in-mem-element() {
    fn:root(<anything/>) instance of document-node()
};

The above should return false, but eXist-db returns true.

declare
    %test:assertEquals("true")
function root:in-mem-document() {
    fn:root(document { <anything/> }) instance of document-node()
};

The above should (and does in eXist-db) return true.

[adamretter]

@wolfgangmm I would welcome a discussion about this. From my perspective it requires quite some re-engineering of the in-memory DOM model, but before I do that... maybe you have some clever ideas to fix this up?

[wolfgangmm]

@adamretter we know where the in-memory DOM is created by a constructor, so could just set a flag.

[duncdrum]

Yes someone working on tei-publisher just stumbled on fn:root()

xquery version "3.0";
declare function local:node-kind
  ( $nodes as node()* )  as xs:string* {

 for $node in $nodes
 return
 if ($node instance of element()) then 'element'
 else if ($node instance of attribute()) then 'attribute'
 else if ($node instance of text()) then 'text'
 else if ($node instance of document-node()) then 'document-node'
 else if ($node instance of comment()) then 'comment'
 else if ($node instance of processing-instruction())
         then 'processing-instruction'
 else 'unknown'
 } ;

let $data :=
<root xml:base="bl">
    <dummy/>
</root>

return
    local:node-kind(root($data))

exist 4.1.0 returns: document-node
Saxon 9.8.0.8 returns: element
Zorba 2.9: returns: element

I also think this is wrong, fn:doc() should give you access to document-nodes, root should not return document-node here.