SPARQL Object Lists and Predicate-Object Lists produce different results

[mielvds]

Hi all,

We notice some incorrect parsing wrt. object lists and predicate object lists.

The following query produces no results:

PREFIX source: <https://data.hetarchief.be/ns/source#>

SELECT ?val1 ?val2
WHERE {
    ?o source:custom_fields [
            source:value        ?val1 ;
         ], [
           source:value        ?val2 ;
         ] .
}

But this one does:

PREFIX source: <https://data.hetarchief.be/ns/source#>

SELECT ?val1 ?val2
WHERE {
    ?o source:custom_fields [
           source:value        ?val1 ;
         ];
         source:custom_fields [
           source:value        ?val2 ;
         ] .
}

According to the spec, or at least how I interpret it, these two queries should be semantically identical. Pyoxigraph returns results for both.