[Autofill] Truncate expiration year based on prediction and max length.

components/autofill/core/browser/autofill_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/autofill_field.h"
 
 #include <stdint.h>
 
 #include "base/command_line.h"
 #include "base/i18n/case_conversion.h"
@@ skipping 422 matching lines @@
     base::string16 abbreviation;
     state_names::GetNameAndAbbreviation(value, nullptr, &abbreviation);
     if (!abbreviation.empty() && field->max_length >= abbreviation.size()) {
       field->value = base::i18n::ToUpper(abbreviation);
       return true;
     }
   }
   return false;
 }
 
+// Fills the expiration year |value| into the |field|. Uses the |field_type|
+// and the |field|'s max_length attribute to determine if the |value| needs to
+// be truncated.
+void FillExpirationYearInput(base::string16 value,
+                             ServerFieldType field_type,
+                             FormFieldData* field) {
+  // If the |field_type| requires only 2 digits, keep only the last 2 digits of
+  // |value|.
+  if (field_type == CREDIT_CARD_EXP_2_DIGIT_YEAR && value.length() > 2)
+    value = value.substr(value.length() - 2, 2);
+
+  if (field->max_length == 0 || field->max_length >= value.size()) {
+    // No length restrictions, fill the year value directly.
+    field->value = value;
+  } else {
+    // Truncate the front of |value| to keep only the number of characters equal
+    // to the |field|'s max length.
+    field->value =
+        value.substr(value.length() - field->max_length, field->max_length);
+  }
+}
+
 std::string Hash32Bit(const std::string& str) {
   std::string hash_bin = base::SHA1HashString(str);
   DCHECK_EQ(base::kSHA1Length, hash_bin.length());
 
   uint32_t hash32 = ((hash_bin[0] & 0xFF) << 24) |
                     ((hash_bin[1] & 0xFF) << 16) | ((hash_bin[2] & 0xFF) << 8) |
                     (hash_bin[3] & 0xFF);
 
   return base::UintToString(hash32);
 }
@@ skipping 134 matching lines @@
   } else if (field_data->form_control_type == "month") {
     return FillMonthControl(value, field_data);
   } else if (type.GetStorableType() == ADDRESS_HOME_STREET_ADDRESS) {
     FillStreetAddress(value, address_language_code, field_data);
     return true;
   } else if (type.GetStorableType() == CREDIT_CARD_NUMBER) {
     FillCreditCardNumberField(field, value, field_data);
     return true;
   } else if (type.GetStorableType() == ADDRESS_HOME_STATE) {
     return FillStateText(value, field_data);
+  } else if (field_data->form_control_type == "input" &&
+             (type.GetStorableType() == CREDIT_CARD_EXP_2_DIGIT_YEAR ||
+              type.GetStorableType() == CREDIT_CARD_EXP_4_DIGIT_YEAR)) {
+    FillExpirationYearInput(value, type.GetStorableType(), field_data);
+    return true;
   }
 
   field_data->value = value;
   return true;
 }
 
 // TODO(crbug.com/581514): Add support for filling only the prefix/suffix for
 // phone numbers with 10 or 11 digits.
 base::string16 AutofillField::GetPhoneNumberValue(
     const AutofillField& field,
@@ skipping 66 matching lines @@
   }
   return best_match;
 }
 
 bool AutofillField::IsCreditCardPrediction() const {
   return AutofillType(server_type_).group() == CREDIT_CARD ||
          AutofillType(heuristic_type_).group() == CREDIT_CARD;
 }
 
 }  // namespace autofill