AutoFillProfile: Don't clobber data on self-assignment

chrome/browser/autofill/credit_card_unittest.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/basictypes.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/autofill/autofill_common_test.h"
 #include "chrome/browser/autofill/credit_card.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 49 matching lines @@
   // Case 4: Have everything.
   CreditCard credit_card4;
   autofill_test::SetCreditCardInfo(&credit_card4, "Corporate",
       "John Dillinger", "123456789012", "01", "2010");
   string16 summary4 = credit_card4.PreviewSummary();
   EXPECT_EQ(string16(ASCIIToUTF16("************9012, Exp: 01/2010")), summary4);
   string16 obfuscated4 = credit_card4.ObfuscatedNumber();
   EXPECT_EQ(string16(ASCIIToUTF16("************9012")), obfuscated4);
 }
 
+TEST(CreditCardTest, AssignmentOperator){
+  CreditCard a, b;
+
+  // Result of assignment should be logically equal to the original profile.
+  autofill_test::SetCreditCardInfo(&a, "Corporate", "John Dillinger",
+                                   "123456789012", "01", "2010");
+  b = a;
+  EXPECT_TRUE(a == b);
+
+  // Assignment to self should not change the profile value.
+  a = a;
+  EXPECT_TRUE(a == b);
+}
+
 }  // namespace