VectorComparer should check null.

Source/wtf/VectorTest.cpp

Index: Source/wtf/VectorTest.cpp
diff --git a/Source/wtf/VectorTest.cpp b/Source/wtf/VectorTest.cpp
index c099e684ae9c4bba8c9744b59cea179a6aaf52ef..9bad0645e2475079092b7cc24f5c59dff4fbae73 100644
--- a/Source/wtf/VectorTest.cpp
+++ b/Source/wtf/VectorTest.cpp
@@ -28,6 +28,7 @@
 #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>
 
@@ -283,4 +284,20 @@ TEST(VectorTest, SwapWithInlineCapacity)
     vectorB.swap(vectorA);
 }
 
+class Comparable {
+};
+bool operator==(const Comparable& a, const Comparable& b) { return true; }
+
+template<typename T> void compare()
+{
+    Vector<T> vector1, vector2;
+    EXPECT_TRUE(vector1 == vector2);

[tkent, 2014/06/16 04:42:26]

More test cases.
 - LHS has internal buffer, RHS has no.
 - LHS has no internal buffer, RHS has.

[yoichio, 2014/06/16 04:58:45]

Done.

+}
+
+TEST(VectorTest, Compare)
+{
+    compare<int>();
+    compare<Comparable>();
+    compare<WTF::String>();
+}
 } // namespace