VectorComparer should check null.

Source/wtf/VectorTest.cpp

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 10 matching lines @@
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 
 #include "wtf/HashSet.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
+#include "wtf/text/WTFString.h"
 #include "wtf/Vector.h"
 #include <gtest/gtest.h>
 
 namespace {
 
 TEST(VectorTest, Basic)
 {
     Vector<int> intVector;
     EXPECT_TRUE(intVector.isEmpty());
     EXPECT_EQ(0ul, intVector.size());
@@ skipping 235 matching lines @@
     EXPECT_EQ(1u, vectorA.size());
     EXPECT_EQ(1, vectorA.at(0).get());
     EXPECT_EQ(3u, vectorB.size());
     EXPECT_EQ(2, vectorB.at(0).get());
     EXPECT_EQ(3, vectorB.at(1).get());
     EXPECT_EQ(4, vectorB.at(2).get());
 
     vectorB.swap(vectorA);
 }
 
+class Comparable {
+};
+bool operator==(const Comparable& a, const Comparable& b) { return true; }
+
+template<typename T> void compare()
+{
+    EXPECT_TRUE(Vector<T>() == Vector<T>());
+    EXPECT_FALSE(Vector<T>(1) == Vector<T>(0));
+    EXPECT_FALSE(Vector<T>() == Vector<T>(1));
+    EXPECT_TRUE(Vector<T>(1) == Vector<T>(1));
+}
+
+TEST(VectorTest, Compare)
+{
+    compare<int>();
+    compare<Comparable>();
+    compare<WTF::String>();
+}
 } // namespace