Don't ever attempt to upload credit cards whose numbers match.

components/autofill/core/browser/credit_card_unittest.cc

 // Copyright 2013 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 <stddef.h>
 
 #include "base/guid.h"
 #include "base/macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 228 matching lines @@
 
     if (test_cases[i].second_card_record_type == CreditCard::MASKED_SERVER_CARD)
       b.SetTypeForMaskedCard(test_cases[i].second_card_type);
 
     EXPECT_EQ(test_cases[i].is_local_duplicate,
               a.IsLocalDuplicateOfServerCard(b)) << " when comparing cards "
                   << a.Label() << " and " << b.Label();
   }
 }
 
+TEST(CreditCardTest, HasSameNumberAs) {
+  CreditCard a(base::GenerateGUID(), std::string());
+  CreditCard b(base::GenerateGUID(), std::string());
+
+  // Empty cards have the same empty number.
+  EXPECT_TRUE(a.HasSameNumberAs(b));
+  EXPECT_TRUE(b.HasSameNumberAs(a));
+
+  // Same number.
+  a.set_record_type(CreditCard::LOCAL_CARD);
+  a.SetRawInfo(CREDIT_CARD_NUMBER, ASCIIToUTF16("4111111111111111"));
+  a.set_record_type(CreditCard::LOCAL_CARD);
+  b.SetRawInfo(CREDIT_CARD_NUMBER, ASCIIToUTF16("4111111111111111"));
+  EXPECT_TRUE(a.HasSameNumberAs(b));
+  EXPECT_TRUE(b.HasSameNumberAs(a));
+
+  // Local cards shouldn't match even if the last 4 are the same.
+  a.set_record_type(CreditCard::LOCAL_CARD);
+  a.SetRawInfo(CREDIT_CARD_NUMBER, ASCIIToUTF16("4111111111111111"));
+  a.set_record_type(CreditCard::LOCAL_CARD);
+  b.SetRawInfo(CREDIT_CARD_NUMBER, ASCIIToUTF16("4111222222221111"));
+  EXPECT_FALSE(a.HasSameNumberAs(b));
+  EXPECT_FALSE(b.HasSameNumberAs(a));
+
+  // Likewise if one is an unmasked server card.
+  a.set_record_type(CreditCard::FULL_SERVER_CARD);
+  EXPECT_FALSE(a.HasSameNumberAs(b));
+  EXPECT_FALSE(b.HasSameNumberAs(a));
+
+  // But if one is a masked card, then they should.
+  b.set_record_type(CreditCard::MASKED_SERVER_CARD);
+  EXPECT_TRUE(a.HasSameNumberAs(b));
+  EXPECT_TRUE(b.HasSameNumberAs(a));
+}
+
 TEST(CreditCardTest, Compare) {
   CreditCard a(base::GenerateGUID(), std::string());
   CreditCard b(base::GenerateGUID(), std::string());
 
   // Empty cards are the same.
   EXPECT_EQ(0, a.Compare(b));
 
   // GUIDs don't count.
   a.set_guid(base::GenerateGUID());
   b.set_guid(base::GenerateGUID());
@@ skipping 409 matching lines @@
   base::string16 card_number = base::ASCIIToUTF16("test");
   int month = 1;
   int year = 3000;
   CreditCard card(card_number, month, year);
   EXPECT_EQ(card_number, card.number());
   EXPECT_EQ(month, card.expiration_month());
   EXPECT_EQ(year, card.expiration_year());
 }
 
 }  // namespace autofill