fix: fix incorrect parent for type reference of a CtParameter (INRIA#…

…3696)

src/main/java/spoon/reflect/factory/ExecutableFactory.java

@@ -79,7 +79,13 @@ public <T> CtParameter<T> createParameter(CtExecutable<?> parent, CtTypeReferenc
 	public <T> CtParameterReference<T> createParameterReference(CtParameter<T> parameter) {
 		CtParameterReference<T> ref = factory.Core().createParameterReference();
 		ref.setSimpleName(parameter.getSimpleName());
-		ref.setType(parameter.getType());
+
+		// true when parameter comes from a lambda expression
+		if (parameter.getType() == null) {
+			ref.setType(parameter.getType());
+		} else {
+			ref.setType(parameter.getType().clone());
+		}
 		return ref;
 	}
 

src/test/java/spoon/test/parameters/ParameterTest.java

@@ -124,4 +124,15 @@ public void testMultiParameterLambdaTypeReference() {
 			assertNull(refType);
 		}
 	}
+
+	@Test
+	public void testGetParentAfterGetParameterReference() {
+		// contract: after getting a parameter reference, the parent of the parameter type reference should still be the parameter itself
+		Launcher spoon = new Launcher();
+		spoon.addInputResource("./src/test/resources/parameter/ParameterResource.java");
+		spoon.buildModel();
+		CtParameter parameter = spoon.getModel().getRootPackage().getElements(new TypeFilter<>(CtParameter.class)).get(0);
+		CtParameterReference pref = parameter.getReference();
+		assertEquals(parameter, parameter.getType().getParent());
+	}
 }

src/test/resources/parameter/ParameterResource.java

@@ -0,0 +1,3 @@
+public class ParameterResource {
+        public void empty(int parameter) { }
+}