AutoFillProfile: Don't clobber data on self-assignment

chrome/browser/autofill/credit_card.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 "chrome/browser/autofill/credit_card.h"
 
 #include <string>
 
 #include "app/l10n_util.h"
 #include "base/basictypes.h"
@@ skipping 357 matching lines @@
 string16 CreditCard::LastFourDigits() const {
   static const size_t kNumLastDigits = 4;
 
   if (number().size() < kNumLastDigits)
     return string16();
 
   return number().substr(number().size() - kNumLastDigits, kNumLastDigits);
 }
 
 void CreditCard::operator=(const CreditCard& credit_card) {
+  if (this == &credit_card)
+    return;
+
   number_ = credit_card.number_;
   name_on_card_ = credit_card.name_on_card_;
   type_ = credit_card.type_;
   last_four_digits_ = credit_card.last_four_digits_;
   expiration_month_ = credit_card.expiration_month_;
   expiration_year_ = credit_card.expiration_year_;
   label_ = credit_card.label_;
   guid_ = credit_card.guid_;
 }
 
@@ skipping 241 matching lines @@
       << UTF16ToUTF8(credit_card.GetFieldText(AutoFillType(CREDIT_CARD_TYPE)))
       << " "
       << UTF16ToUTF8(credit_card.GetFieldText(AutoFillType(CREDIT_CARD_NUMBER)))
       << " "
       << UTF16ToUTF8(credit_card.GetFieldText(
              AutoFillType(CREDIT_CARD_EXP_MONTH)))
       << " "
       << UTF16ToUTF8(credit_card.GetFieldText(
              AutoFillType(CREDIT_CARD_EXP_4_DIGIT_YEAR)));
 }