Concept Intersection fails

[Aklakan]

filterConcept := "?s http://geovocab.org/geometry#geometry ?fv_2; ?fv_2"

attrConcept := "?s http://www.opengis.net/ont/geosparql#asWKT ?w; ?s"

intersection using ConceptUtils.createCombinedConcept(attrConcept, filterConcept, true, false, false) yields

actual := "?s http://geovocab.org/geometry#geometry ?s . ?s http://www.opengis.net/ont/geosparql#asWKT ?w; ?s"

expected := "?freshVar http://geovocab.org/geometry#geometry ?s . ?s http://www.opengis.net/ont/geosparql#asWKT ?w; ?s"

with ?freshVar being a newly allocated variable distinct from any other variable

[Aklakan]

Added hacky fix, which does additional variable renaming by prefixing, but does not actually check for uniquness (if javascript just had a native HashSet....)