an empty return statement does not return a value (PY-4502)

python/src/com/jetbrains/python/inspections/PyPropertyDefinitionInspection.java

@@ -274,7 +274,8 @@ public class PyPropertyDefinitionInspection extends PyInspection {
         final PsiElement[] returnStatements = PsiTreeUtil.collectElements(callable, new PsiElementFilter() {
           @Override
           public boolean isAccepted(PsiElement element) {
-            return (element instanceof PyReturnStatement) || (element instanceof PyYieldExpression);
+            return (element instanceof PyReturnStatement && ((PyReturnStatement) element).getExpression() != null) ||
+                   (element instanceof PyYieldExpression);
           }
         });
         hasReturns = returnStatements.length > 0; 

python/testData/inspections/PyPropertyDefinitionInspection26/src/prop_test.py

@@ -46,4 +46,11 @@ class A(object):
   def futuroo(self):
     raise NotImplementedError("Override!") # ok though no return
 
+  @property
+  def xoo(self):
+    return self._x
 
+  @xoo.setter
+  def xoo(self, x):
+    self._x = x
+    return