[dotNetRDF-bugs] Problem serializing to NQuads

[Tomasz P. <tom...@gm...>]

Hi

We've noticed weird behaviour with in-memory triple store, when
serializing to NQuads. Here's what happens:

1. Create an empty TripleStore
2. Run UPDATE

INSERT DATA {
GRAPH <http://test.org/user> {
<http://test.org/user>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://schema.org/Person> .
<http://test.org/user> <http://some/ontology/favorite>
<http://test.org/product/name> .
}
GRAPH <http://test.org/prodList/> {
<http://test.org/user> <http://xmlns.com/foaf/0.1/primaryTopic>
<http://test.org/user> .
}
}

3. Serialize to NQuads. Store Manager correctly informs that 3 triple
were serialized in 3 graphs (including empty default graph).

The output file contains all triples, but without graph names. Thus
they are all serialized in the default graph. It's not a problem with
the store in-memory. The insert creates correct graph with data.
I've confirmed this occurs in all version since 1.0.0.

Curiously only when data is loaded with a LOAD <x> INTO GRAPH <y>
command or with dNetRDF API, the store is serialized correctly. Only
INSERT DATA causes the problem.

Is this a known problem?

And by the way. Why INSERT DATA creates an empty default graph in the
store while loading or LOAD <x> only creates those graphs actually
included in the source files?

Greets,
Tom