empty namespace allowed

In accordance with Avro specification: http://avro.apache.org/docs/1.9.1/spec.html#names

Resolves: linkedin#177

name.go

@@ -121,8 +121,8 @@ func newNameFromSchemaMap(enclosingNamespace string, schemaMap map[string]interf
 	}
 	if namespace, ok := schemaMap["namespace"]; ok {
 		namespaceString, ok = namespace.(string)
-		if !ok || namespaceString == nullNamespace {
-			return nil, fmt.Errorf("schema namespace, if provided, ought to be non-empty string; received: %T: %v", namespace, namespace)
+		if !ok {
+			return nil, fmt.Errorf("schema namespace, if provided, ought to be a string; received: %T: %v", namespace, namespace)
 		}
 	}
 

name_test.go

@@ -82,3 +82,19 @@ func TestNameWithoutDotsButWithEmptyNamespaceAndEnclosingName(t *testing.T) {
 		t.Errorf("GOT: %#v; WANT: %#v", actual, expected)
 	}
 }
+
+func TestNewNameFromSchemaMap(t *testing.T) {
+	n, err := newNameFromSchemaMap(nullNamespace, map[string]interface{}{
+		"name":      "foo",
+		"namespace": "",
+		"type":      map[string]interface{}{},
+	})
+	ensureError(t, err)
+
+	if got, want := n.fullName, "foo"; got != want {
+		t.Errorf("GOT: %q; WANT: %q", got, want)
+	}
+	if got, want := n.namespace, ""; got != want {
+		t.Errorf("GOT: %q; WANT: %q", got, want)
+	}
+}