Turtle writer does not respect namespaces in IRIs

[reckart]

Current Behavior

The turtle writer does not consider the namespace provided by an IRI. Instead, it turns the IRI into a string and then tries to derive a namespace from that string and then looks up that namespace in the namespace table.

Expected Behavior

If the IRI defines a namespace, that should first be used to look up the prefix in the namespace table. Interpreting the IRI as a string should only be a fallback.

Steps To Reproduce

	@Test
	public void testIriNamespace() throws Exception {
	    Model model = new DynamicModelFactory().createEmptyModel();
	    String prefix = "foo-bar";
        String ns = "foo:this.is.my.bar.";
        model.setNamespace(prefix, ns);
	    model.add(vf.createIRI(ns, "lala"), vf.createIRI(ns, "lulu"), vf.createIRI(ns, "lolo"));

        StringWriter stringWriter = new StringWriter();
	    Rio.write(model, stringWriter, RDFFormat.TURTLE);
	    
	    assertThat(stringWriter.toString()).contains("foo-bar:lala foo-bar:lulu foo-bar:lolo .");
	}

Version

4.3.9

Are you interested in contributing a solution yourself?

Yes

Anything else?

No response