Autofill: Allow forms to have multiple distinct CC number inputs.

components/autofill/core/browser/credit_card_field.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 "components/autofill/core/browser/credit_card_field.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 12 matching lines @@
 // [Ref: http://en.wikipedia.org/wiki/Bank_card_number]
 static const size_t kMaxValidCardNumberSize = 19;
 
 // static
 FormField* CreditCardField::Parse(AutofillScanner* scanner) {
   if (scanner->IsEnd())
     return NULL;
 
   scoped_ptr<CreditCardField> credit_card_field(new CreditCardField);
   size_t saved_cursor = scanner->SaveCursor();
-  bool form_has_valid_card_number_fields = true;
 
   // Credit card fields can appear in many different orders.
   // We loop until no more credit card related fields are found, see |break| at
   // bottom of the loop.
   for (int fields = 0; !scanner->IsEnd(); ++fields) {
     // Ignore gift card fields.
     if (ParseField(scanner, base::UTF8ToUTF16(autofill::kGiftCardRe), NULL))
       break;
 
     // Sometimes the cardholder field is just labeled "name". Unfortunately this
@@ skipping 55 matching lines @@
     AutofillField* current_number_field;
     if (ParseField(scanner, pattern, &current_number_field)) {
       // Avoid autofilling any credit card number field having very low or high
       // |start_index| on the HTML form.
       size_t start_index = 0;
       if (!credit_card_field->numbers_.empty()) {
         size_t last_number_field_size =
             credit_card_field->numbers_.back()->credit_card_number_offset() +
             credit_card_field->numbers_.back()->max_length;
 
-        // In some cases, HTML form may have credit card number split across
-        // multiple input fields and either one or cumulatively having
-        // |max_length| more than |kMaxValidCardNumberSize|, mark these input
-        // form fields as invalid and skip autofilling them.
-        if (last_number_field_size == 0U ||
-            last_number_field_size >= kMaxValidCardNumberSize) {
-          // Mark that the credit card number splits are invalid. But keep
-          // scanning HTML form so that cursor moves beyond related fields.
-          form_has_valid_card_number_fields = false;
-        }
-
-        start_index = last_number_field_size;
+        // Distinguish between
+        //   (a) one card split across multiple fields
+        //   (b) multiple fields for multiple cards
+        // Treat this field as a part of the same card as the last field, except
+        // when doing so would cause overflow.
+        if (last_number_field_size < kMaxValidCardNumberSize)
+          start_index = last_number_field_size;
       }
 
       current_number_field->set_credit_card_number_offset(start_index);
       credit_card_field->numbers_.push_back(current_number_field);
       continue;
     }
 
     if (LowerCaseEqualsASCII(scanner->Cursor()->form_control_type, "month")) {
       credit_card_field->expiration_date_ = scanner->Cursor();
       scanner->Advance();
@@ skipping 53 matching lines @@
     // field; we parse this field but ignore it.
     // We also ignore any other fields within a credit card block that
     // start with "card", under the assumption that they are related to
     // the credit card section being processed but are uninteresting to us.
     if (ParseField(scanner, base::UTF8ToUTF16(autofill::kCardIgnoredRe), NULL))
       continue;
 
     break;
   }
 
-  // Cases where heuristic misinterprets input field as credit card number
-  // field, refuse to autofill credit card number fields.
-  if (!form_has_valid_card_number_fields)
-    credit_card_field->numbers_.clear();
-
   // Some pages have a billing address field after the cardholder name field.
   // For that case, allow only just the cardholder name field.  The remaining
   // CC fields will be picked up in a following CreditCardField.
   if (credit_card_field->cardholder_)
     return credit_card_field.release();
 
   // On some pages, the user selects a card type using radio buttons
   // (e.g. test page Apple Store Billing.html).  We can't handle that yet,
   // so we treat the card type as optional for now.
   // The existence of a number or cvc in combination with expiration date is
   // a strong enough signal that this is a credit card.  It is possible that
   // the number and name were parsed in a separate part of the form.  So if
   // the cvc and date were found independently they are returned.
   if ((!credit_card_field->numbers_.empty() ||
-       credit_card_field->verification_ ||
-       !form_has_valid_card_number_fields) &&
+       credit_card_field->verification_) &&
       (credit_card_field->expiration_date_ ||
        (credit_card_field->expiration_month_ &&
         credit_card_field->expiration_year_))) {
     return credit_card_field.release();
   }
 
   scanner->RewindTo(saved_cursor);
   return NULL;
 }
 
@@ skipping 42 matching lines @@
 
 ServerFieldType CreditCardField::GetExpirationYearType() const {
   return (expiration_date_
               ? exp_year_type_
               : ((expiration_year_ && expiration_year_->max_length == 2)
                      ? CREDIT_CARD_EXP_2_DIGIT_YEAR
                      : CREDIT_CARD_EXP_4_DIGIT_YEAR));
 }
 
 }  // namespace autofill