Doubled XML entities

[scriptin]

Example XML:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE test [
<!ENTITY test "test entity">
]>
<test>
  <a>&test;</a>
  <a>&test;</a>
  <a>&test;</a>
</test>

convert.xq:

xquery version "3.0";
module namespace convert = "convert";

declare function convert:convert-entity($text as xs:string) as xs:string? {
  switch($text)
  case "test entity" return "test"
  default return error(xs:QName("unknown-entity"), concat("Unknown entity '", $text, "'"))
};

test.xq:

xquery version "3.0";

import module namespace jx = "http://zorba.io/modules/json-xml";
import module namespace convert = "convert" at "convert.xq";

declare variable $doc external;

jx:xml-to-json(
  <json type="object">
    <pair name="words" type="array">
      { for $word in $doc/test/a
        return <item type="string"> { convert:convert-entity($word/text()) } </item> }
    </pair>
  </json>
)

Run: zorba -i -e doc=test.xml test.xq > test.json

Expected result: JSON file containing an array of 3 strings "test".
Actual result: </home/dmitry/test/convert.xq>:7,18: error [unknown-entity]: Unknown entity 'test entitytest entity'

All entities, starting from a second one encountered during parsing, are parsed as "doubled", i.e. a string is concatenated with itself. In the example above, test entity becomes test entitytest entity.

[scriptin]

I'm using Ubuntu 16.04.2 LTS

$ zorba -v
Zorba NoSQL Query Processor, Version: 3.1.0