From 9ad1a4df47e9d008581968c6f458a94f47a68375 Mon Sep 17 00:00:00 2001
From: Matthew Jason Benson <mbenson@apache.org>
Date: Mon, 23 Sep 2013 23:43:13 +0000
Subject: [PATCH] null-guard

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@1525740 13f79535-47bb-0310-9956-ffa450edef68
---
 src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java b/src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java
index 1e20f5c10..3daeee1b0 100644
--- a/src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java
+++ b/src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java
@@ -24,6 +24,7 @@ import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
 import java.lang.reflect.WildcardType;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -1261,6 +1262,9 @@ public class TypeUtils {
      * @return Type
      */
     public static Type unrollVariables(Map<TypeVariable<?>, Type> typeArguments, final Type type) {
+        if (typeArguments == null) {
+            typeArguments = Collections.<TypeVariable<?>, Type> emptyMap();
+        }
         if (containsTypeVariables(type)) {
             if (type instanceof TypeVariable<?>) {
                 return unrollVariables(typeArguments, typeArguments.get(type));