Make CI_Form_validation::error()'s first parameter mandatory and add a typehint for CI_Form_validation::error()
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 5ea2f81..c02abbb 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -248,9 +248,9 @@
 	 * @param	array	$data
 	 * @return	void
 	 */
-	public function set_data($data = '')
+	public function set_data(array $data)
 	{
-		if ( ! empty($data) && is_array($data))
+		if ( ! empty($data))
 		{
 			$this->validation_data = $data;
 		}
@@ -304,12 +304,12 @@
 	 *
 	 * Gets the error message associated with a particular field
 	 *
-	 * @param	string	the field name
-	 * @param	string	the html start tag
-	 * @param 	strign	the html end tag
+	 * @param	string	$field	Field name
+	 * @param	string	$prefix	HTML start tag
+	 * @param 	strign	$suffix	HTML end tag
 	 * @return	string
 	 */
-	public function error($field = '', $prefix = '', $suffix = '')
+	public function error($field, $prefix = '', $suffix = '')
 	{
 		if (empty($this->_field_data[$field]['error']))
 		{