PDOException: SQLSTATE[22001]: String data, right truncated: 1406 Data too long in in field_sql_storage_field_storage_write()

When submitting the node form, I've the following fatal error:

PDOException: SQLSTATE[22001]: String data, right truncated: 1406 Data too long for column 'field_contact_form_country_value' at row 1: INSERT INTO {field_data_field_contact_form_country} (entity_type, entity_id, revision_id, bundle, delta, language, field_contact_form_country_value, field_contact_form_country_format) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => node [:db_insert_placeholder_1] => 4494 [:db_insert_placeholder_2] => 4776 [:db_insert_placeholder_3] => contact_form [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => und [:db_insert_placeholder_6] => All [:db_insert_placeholder_7] => ) in field_sql_storage_field_storage_write() (line 452 of modules/field/modules/field_sql_storage/field_sql_storage.module).

Executed code:

 >=> class DatabaseStatementBase { public $dbh = class DatabaseConnection_mysql { protected $needsCleanup = FALSE; protected $target = 'default'; protected $key = 'default'; protected $logger = NULL; protected $transactionLayers = array (...); protected $driverClasses = array (...); protected $statementClass = 'DatabaseStatementBase'; protected $transactionSupport = TRUE; protected $transactionalDDLSupport = FALSE; protected $temporaryNameIndex = 0; protected $connectionOptions = array (...); protected $schema = class DatabaseSchema_mysql { ... }; protected $prefixes = array (...); protected $prefixSearch = array (...); protected $prefixReplace = array (...) }; public $queryString = 'INSERT INTO field_data_field_contact_form_country (entity_type, entity_id, revision_id, bundle, delta, language, field_contact_form_country_value, field_contact_form_country_format) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7)' }
                                                                                   >=> class DatabaseStatementBase { public $dbh = class DatabaseConnection_mysql { protected $needsCleanup = FALSE; protected $target = 'default'; protected $key = 'default'; protected $logger = NULL; protected $transactionLayers = array (...); protected $driverClasses = array (...); protected $statementClass = 'DatabaseStatementBase'; protected $transactionSupport = TRUE; protected $transactionalDDLSupport = FALSE; protected $temporaryNameIndex = 0; protected $connectionOptions = array (...); protected $schema = class DatabaseSchema_mysql { ... }; protected $prefixes = array (...); protected $prefixSearch = array (...); protected $prefixReplace = array (...) }; public $queryString = 'INSERT INTO field_data_field_contact_form_country (entity_type, entity_id, revision_id, bundle, delta, language, field_contact_form_country_value, field_contact_form_country_format) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7)' }
                                                                                   => $stmt = class DatabaseStatementBase { public $dbh = class DatabaseConnection_mysql { protected $needsCleanup = FALSE; protected $target = 'default'; protected $key = 'default'; protected $logger = NULL; protected $transactionLayers = array (...); protected $driverClasses = array (...); protected $statementClass = 'DatabaseStatementBase'; protected $transactionSupport = TRUE; protected $transactionalDDLSupport = FALSE; protected $temporaryNameIndex = 0; protected $connectionOptions = array (...); protected $schema = class DatabaseSchema_mysql { ... }; protected $prefixes = array (...); protected $prefixSearch = array (...); protected $prefixReplace = array (...) }; public $queryString = 'INSERT INTO field_data_field_contact_form_country (entity_type, entity_id, revision_id, bundle, delta, language, field_contact_form_country_value, field_contact_form_country_format) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7)' } includes/database/database.inc:679    2.0660  108926864                                                             -> DatabaseStatementBase->execute($args = array (':db_insert_placeholder_0' => 'node', ':db_insert_placeholder_1' => '4494', ':db_insert_placeholder_2' => '4776', ':db_insert_placeholder_3' => 'contact_form', ':db_insert_placeholder_4' => 0, ':db_insert_placeholder_5' => 'und', ':db_insert_placeholder_6' => 'All', ':db_insert_placeholder_7' => NULL), $options = array ('target' => 'default', 'return' => 3, 'fetch' => 5, 'throw_exception' => TRUE)) includes/database/database.inc:680

Related issues:
#1015916: Image field "title" allows more data than database column size.

Field definition:

// Exported field_base: 'field_contact_form_country'
$field_bases['field_contact_form_country'] = array(
  'active' => 1,
  'cardinality' => 1,
  'deleted' => 0,
  'entity_types' => array(),
  'field_name' => 'field_contact_form_country',
  'foreign keys' => array(
    'format' => array(
      'columns' => array(
        'format' => 'format',
      ),
      'table' => 'filter_format',
    ),
  ),
  'indexes' => array(
    'format' => array(
      0 => 'format',
    ),
  ),
  'locked' => 0,
  'module' => 'text',
  'settings' => array(
    'entity_translation_sync' => FALSE,
    'max_length' => 2,
  ),
  'translatable' => 0,
  'type' => 'text',
);

Submit code looks like this:

function foo_contact_form_submit($form, $form_state) {
  $node = node_form_submit_build_node($form, $form_state);

  $node->field_contact_form_country[LANGUAGE_NONE][0]['value'] = foo_regional_get_current_country(); // which has the value: Array ( [und] => Array ( [0] => Array ( [value] => All ) ) )

  node_save($node);

It is a bug?