From 7ca3432cacd0ea3bce8501ef077aa56bd24bea60 Mon Sep 17 00:00:00 2001
From: Dmitry Jemerov <yole@jetbrains.com>
Date: Thu, 11 Aug 2011 17:31:29 +0200
Subject: [PATCH] allow passing null to PyType.union()

---
 python/src/com/jetbrains/python/psi/types/PyUnionType.java | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/python/src/com/jetbrains/python/psi/types/PyUnionType.java b/python/src/com/jetbrains/python/psi/types/PyUnionType.java
index 31299c412b6c..f20035b5f384 100644
--- a/python/src/com/jetbrains/python/psi/types/PyUnionType.java
+++ b/python/src/com/jetbrains/python/psi/types/PyUnionType.java
@@ -73,6 +73,12 @@ public class PyUnionType implements PyType {
 
   @Nullable
   public static PyType union(PyType type1, PyType type2) {
+    if (type2 == null) {
+      return type1;
+    }
+    if (type1 == null) {
+      return type2;
+    }
     if (type1 instanceof PyTupleType && type2 instanceof PyTupleType) {
       final PyTupleType tupleType1 = (PyTupleType)type1;
       final PyTupleType tupleType2 = (PyTupleType)type2;