empty namespace prefix cannot be used

[mhgrove]

From the mailing list:

@namespaces({"","http://purl.org/net/grafli#"
,"owl","http://www.w3.org/2002/07/owl#"
,"rdf","http://www.w3.org/1999/02/22-rdf-syntax-ns#"
,"xml","http://www.w3.org/XML/1998/namespace"
,"xsd","http://www.w3.org/2001/XMLSchema#"
,"foaf","http://xmlns.com/foaf/0.1/"
,"rdfs","http://www.w3.org/2000/01/rdf-schema#"
,"skos2","http://www.w3.org/2008/05/skos#"
})

When I run a query using the empty qname e.g.

aManager.createQuery("where {?result a :SequencingRun; :wasAssociatedWith [a foaf:Person; foaf:accountName 'JohnPe']}")

[mhgrove]

Inspecting the contents of PrefixManager.GLOBAL immediately before constructing the query, the default namespace (empty prefix) is certainly present; I think the immediate cause of its absence in the constructed query is the block that explicitly excludes the empty prefix in
com.clarkparsia.empire.impl.sparql.SPARQLDialect.insertNamespaces():
if (aPrefix.trim().equals("")) {
continue;
}
But I don't know why that is there so I'm not going to mess with it :)

in com.clarkparsia.empire.impl.sparql.SPARQLDialect.insertNamespaces()