[unrelated] Avoid NPE for QVTr sourceless relation calls
diff --git a/examples/org.eclipse.ocl.examples.codegen/src/org/eclipse/ocl/examples/codegen/analyzer/CG2StringVisitor.java b/examples/org.eclipse.ocl.examples.codegen/src/org/eclipse/ocl/examples/codegen/analyzer/CG2StringVisitor.java
index 6f3837d..87c9368 100644
--- a/examples/org.eclipse.ocl.examples.codegen/src/org/eclipse/ocl/examples/codegen/analyzer/CG2StringVisitor.java
+++ b/examples/org.eclipse.ocl.examples.codegen/src/org/eclipse/ocl/examples/codegen/analyzer/CG2StringVisitor.java
@@ -654,7 +654,7 @@
 		safeVisit(source);
 		OperationCallExp operationCallExp = (OperationCallExp) oc.getAst();
 		Operation oper = operationCallExp.getReferredOperation();
-		Type sourceType = source != null ? operationCallExp.getOwnedSource().getType() : null;
+		Type sourceType = operationCallExp.getOwnedSource() != null ? operationCallExp.getOwnedSource().getType() : null;
 		append(PivotUtil.getNavigationOperator(false/*operationCallExp.isIsSafe()*/, PivotUtil.isAggregate(sourceType)));
 		appendName(oper);
 		append("(");