Bnode rewriting does not work in VALUE blocks

[Aklakan]

ExprTransformVirtualBnodeUris correctly transforms

SELECT * { ?s ?p ?o FILTER(?s = <bnode://foo>) }

into

SELECT * { ?s ?p ?o FILTER(bnodeLabel(?s) = "foo") }

But when specifying a set of bnode IRIs as a VALUES block such as VALUES ?s { <bnode://foo> <bnode://bar> } then filter conditions are not updated and/or injected appropriately.

One solution using our custom bnode function would be to rename VALUE block variables which may be become bound to bnode IRIs and then add a subsequent BIND statement afterwards:

VALUES ?s { <bnode://foo> <bnode://bar> }

becomes

VALUES ?sRaw { <bnode://foo> <bnode://bar> }
BIND(if(strstarts(str(?s), 'bnode://'), norse:bnode.asGiven(extractLabel(?s), ?sRaw)  AS ?s)

The portable approach would be to still rename the variables of the VALUES blocks but then add appropriate FILTER statements to the graph patterns:

VALUES ?sRaw { ... }
?s ?p ?o
FILTER (toBnodeIri(?s) = ?sRaw)