Bug Round-tripping HAVING clauses to an SSE and back

[Rick Moynihan]

Hi all,

I've been using the recent fixes to ARQ (made in JENA-954) around rendering
SPARQL queries and have encountered another problem where a valid query
appears to roundtrip to an invalid one.

The problematic query is this:

SELECT ?obs
WHERE {
  ?obs a qb:Observation ;
         qb:measureType ?measure ;
         ?measure ?value ;
         .
}
GROUP BY ?obs
HAVING (COUNT(?value) > 1)

Which generates this SSE:

(project
  (?obs)
  (filter
    (> ?.0 1)
    (group
      (?obs)
      ((?.0
        (count ?value)))
      (bgp
        (triple ?obs <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <
http://purl.org/linked-data/cube#Observation>)
        (triple ?obs <http://purl.org/linked-data/cube#measureType>
?measure)
        (triple ?obs ?measure ?value)))))

But when round tripped back into SPARQL with OpAsQuery.asQuery, leads to
this invalid query:

SELECT  ?obs
WHERE
  { ?obs <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> qb:Observation .
    ?obs qb:measureType ?measure .
    ?obs ?measure ?value
    FILTER ( ?.0 > 1 )
  }
GROUP BY ?obs


R.