serialize bnode graph ids in trig correctly

2 files changed, 23 insertions, 19 deletions

diff --git a/rdflib/plugins/serializers/trig.py b/rdflib/plugins/serializers/trig.py
index b30d10c8..f8bd789d 100644
--- a/rdflib/plugins/serializers/trig.py
+++ b/rdflib/plugins/serializers/trig.py
@@ -68,9 +68,12 @@ class TrigSerializer(TurtleSerializer):
             if self.default_context and store.identifier==self.default_context:
                 self.write(self.indent() + '\n{')
             else:
-                iri = self.getQName(store.identifier)
-                if iri is None:
-                    iri = '<%s>' % store.identifier
+                if isinstance(store.identifier, BNode):
+                    iri = store.identifier.n3()
+                else:
+                    iri = self.getQName(store.identifier)
+                    if iri is None:
+                        iri = store.identifier.n3()
                 self.write(self.indent() + '\n%s {' % iri)
 
             self.depth += 1
diff --git a/test/test_trig.py b/test/test_trig.py
index 742e3281..c985e002 100644
--- a/test/test_trig.py
+++ b/test/test_trig.py
@@ -4,6 +4,10 @@ import re
 
 from rdflib.py3compat import b
 
+TRIPLE = (rdflib.URIRef("http://example.com/s"),
+          rdflib.RDFS.label,
+          rdflib.Literal("example 1"))
+
 class TestTrig(unittest.TestCase):
 
     def testEmpty(self):
@@ -49,10 +53,7 @@ class TestTrig(unittest.TestCase):
 
     def testRememberNamespace(self):
         g = rdflib.ConjunctiveGraph()
-        g.add((rdflib.URIRef("http://example.com/s"),
-               rdflib.RDFS.label,
-               rdflib.Literal("example 1"),
-               rdflib.URIRef("http://example.com/graph1")))
+        g.add(TRIPLE + (rdflib.URIRef("http://example.com/graph1"),))
         # In 4.2.0 the first serialization would fail to include the
         # prefix for the graph but later serialize() calls would work.
         first_out = g.serialize(format='trig')
@@ -60,24 +61,24 @@ class TestTrig(unittest.TestCase):
         self.assertIn(b'@prefix ns1: <http://example.com/> .', second_out)
         self.assertIn(b'@prefix ns1: <http://example.com/> .', first_out)
 
-        print first_out
-
     def testGraphQnameSyntax(self):
         g = rdflib.ConjunctiveGraph()
-        g.add((rdflib.URIRef("http://example.com/s"),
-               rdflib.RDFS.label,
-               rdflib.Literal("example 1"),
-               rdflib.URIRef("http://example.com/graph1")))
+        g.add(TRIPLE + (rdflib.URIRef("http://example.com/graph1"),))
         out = g.serialize(format='trig')
         self.assertIn(b'ns1:graph1 {', out)
 
     def testGraphUriSyntax(self):
         g = rdflib.ConjunctiveGraph()
-        g.add((rdflib.URIRef("http://example.com/s"),
-               rdflib.RDFS.label,
-               rdflib.Literal("example 1"),
-               # getQName will not abbreviate this, so it should come
-               # out as a '<...>' term.
-               rdflib.URIRef("http://example.com/foo.")))
+        # getQName will not abbreviate this, so it should serialize as
+        # a '<...>' term.
+        g.add(TRIPLE + (rdflib.URIRef("http://example.com/foo."),))
         out = g.serialize(format='trig')
         self.assertIn(b'<http://example.com/foo.> {', out)
+
+    def testBlankGraphIdentifier(self):
+        g = rdflib.ConjunctiveGraph()
+        g.add(TRIPLE + (rdflib.BNode(),))
+        out = g.serialize(format='trig')
+        graph_label_line = out.splitlines()[-4]
+        self.assert_(re.match(br'^_:[a-zA-Z0-9]+ \{', graph_label_line))
+