OpenLink Virtuoso (Open-Source Edition)

My current problem seems to be a regression in the 20090612 snapshot, since
it
is not at a problem with the 20090504 snapshot.

The problematic query is this one:

prefix rdfs:<http://www.w3.org/2000/01/rdf-schema#>
prefix dct:<http://purl.org/dc/terms/>
CONSTRUCT { ?resource a ?type ; rdfs:label ?title . }
FROM <http://msone.computas.no/graphs>
FROM NAMED <http://msone.computas.no/graphs/ontology/mediasone>
FROM NAMED <http://msone.computas.no/graphs/ontology/mediasone>
FROM NAMED
<http://msone.computas.no/graphs/inferred/nfi/agent-classification>
FROM NAMED
<http://msone.computas.no/graphs/inferred/mo/agent-classification>
FROM NAMED <http://msone.computas.no/graphs/instance/nfi>
FROM NAMED <http://msone.computas.no/graphs/instance/mo>
WHERE {
{
?ontology a <http://msone.computas.no/graphs#OntoGraph> .
GRAPH ?ontology
{
?resource a ?type .
FILTER (?type = <http://www.w3.org/2002/07/owl#Class> ) .
?resource rdfs:label ?title .
} } UNION {
?instances a <http://msone.computas.no/graphs#InstanceGraph> .
GRAPH ?instances
{
?resource a ?type .
FILTER (?type = <http://creativecommons.org/ns#Work> ) .
?resource dct:title ?title .
}
}
FILTER regex(?title, "PÅL", "i")
}

The problem is well demonstrated by launching the query at two endpoints,
that
(according to my cow-orkers) run exactly the same data:

http://msonetest:8890/sparql?default-graph-uri=&query=prefix+rdfs%3A%3Chttp
%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E%0D%0Aprefix+dct%3A%3Chtt
p%3A%2F%2Fpurl.org%2Fdc%2Fterms%2F%3E%0D%0A+CONSTRUCT+%7B+%3Fresource+a+%3F
type+%3B+rdfs%3Alabel+%3Ftitle+.
+%7D++%0D%0AFROM+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%3E++%0D%0AFROM+
NAMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Fontology%2Fmediasone%3E+
%0D%0AFROM+NAMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Fontology%2Fme
diasone%3E%0D%0AFROM+NAMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Finf
erred%2Fnfi%2Fagent-classification%3E%0D%0AFROM+NAMED+%3Chttp%3A%2F%2Fmsone
.computas.no%2Fgraphs%2Finferred%2Fmo%2Fagent-classification%3E%0D%0AFROM+N
AMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Finstance%2Fnfi%3E%0D%0AFR
OM+NAMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Finstance%2Fmo%3E%0D%0
AWHERE+%7B+%0D%0A+%7B+%0D%0A++%3Fontology+a+%3Chttp%3A%2F%2Fmsone.computas.
no%2Fgraphs%23OntoGraph%3E+.
+%0D%0A++GRAPH+%3Fontology+++%0D%0A++%7B+%0D%0A+++++%3Fresource+a+%3Ftype+.

+%0D%0A+++++FILTER+%28%3Ftype+%3D+%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2F
owl%23Class%3E+%29+.
+%0D%0A+++++%3Fresource+rdfs%3Alabel+%3Ftitle+.
+%0D%0A++%7D+%7D+UNION+%7B%0D%0A++%3Finstances+a+%3Chttp%3A%2F%2Fmsone.comp
utas.no%2Fgraphs%23InstanceGraph%3E+.
+%0D%0A++GRAPH+%3Finstances++%0D%0A++%7B+%0D%0A++++%3Fresource+a+%3Ftype+.
+%0D%0A++++FILTER+%28%3Ftype+%3D+%3Chttp%3A%2F%2Fcreativecommons.org%2Fns%2
3Work%3E+%29+.
+%0D%0A++++%3Fresource+dct%3Atitle+%3Ftitle+.
+%0D%0A++%7D+%0D%0A+%7D%0D%0AFILTER+regex%28%3Ftitle%2C+%22P%C3%85L%22%2C+%
22i%22%29++%0D%0A%7D+&format=text%2Frdf%2Bn3&debug=on

vs:

http://msone:8890/sparql?default-graph-uri=&query=prefix+rdfs%3A%3Chttp%3A%
2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E%0D%0Aprefix+dct%3A%3Chttp%3A
%2F%2Fpurl.org%2Fdc%2Fterms%2F%3E%0D%0A+CONSTRUCT+%7B+%3Fresource+a+%3Ftype
+%3B+rdfs%3Alabel+%3Ftitle+.
+%7D++%0D%0AFROM+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%3E++%0D%0AFROM+
NAMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Fontology%2Fmediasone%3E+
%0D%0AFROM+NAMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Fontology%2Fme
diasone%3E%0D%0AFROM+NAMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Finf
erred%2Fnfi%2Fagent-classification%3E%0D%0AFROM+NAMED+%3Chttp%3A%2F%2Fmsone
.computas.no%2Fgraphs%2Finferred%2Fmo%2Fagent-classification%3E%0D%0AFROM+N
AMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Finstance%2Fnfi%3E%0D%0AFR
OM+NAMED+%3Chttp%3A%2F%2Fmsone.computas.no%2Fgraphs%2Finstance%2Fmo%3E%0D%0
AWHERE+%7B+%0D%0A+%7B+%0D%0A++%3Fontology+a+%3Chttp%3A%2F%2Fmsone.computas.
no%2Fgraphs%23OntoGraph%3E+.
+%0D%0A++GRAPH+%3Fontology+++%0D%0A++%7B+%0D%0A+++++%3Fresource+a+%3Ftype+.

+%0D%0A+++++FILTER+%28%3Ftype+%3D+%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2F
owl%23Class%3E+%29+.
+%0D%0A+++++%3Fresource+rdfs%3Alabel+%3Ftitle+.
+%0D%0A++%7D+%7D+UNION+%7B%0D%0A++%3Finstances+a+%3Chttp%3A%2F%2Fmsone.comp
utas.no%2Fgraphs%23InstanceGraph%3E+.
+%0D%0A++GRAPH+%3Finstances++%0D%0A++%7B+%0D%0A++++%3Fresource+a+%3Ftype+.
+%0D%0A++++FILTER+%28%3Ftype+%3D+%3Chttp%3A%2F%2Fcreativecommons.org%2Fns%2
3Work%3E+%29+.
+%0D%0A++++%3Fresource+dct%3Atitle+%3Ftitle+.
+%0D%0A++%7D+%0D%0A+%7D%0D%0AFILTER+regex%28%3Ftitle%2C+%22P%C3%85L%22%2C+%
22i%22%29++%0D%0A%7D+&format=text%2Frdf%2Bn3&debug=on

In the latter case, we get the expected behaviour, which is that all
literals
are matched by "PÅL". In the former case, it doesn't seem to filter at
all,
so we simply get a big dump.

I am afraid I have not been able to narrow this down further, as if I
remove
either of UNIONs, the match appears to be OK.

However, since this seems to be a problem recently introduced, I hope it
can
be tracked down nevertheless.