Fix bcit-ci#1957

system/libraries/Form_validation.php

@@ -440,11 +440,10 @@ public function run($group = '')
 		// Load the language file containing error messages
 		$this->CI->lang->load('form_validation');
 
-		// Cycle through the rules for each field, match the
-		// corresponding $_POST item and test for errors
+		// Cycle through the rules for each field and match the corresponding $validation_data item
 		foreach ($this->_field_data as $field => $row)
 		{
-			// Fetch the data from the corresponding $_POST or validation array and cache it in the _field_data array.
+			// Fetch the data from the validation_data array item and cache it in the _field_data array.
 			// Depending on whether the field name is an array or a string will determine where we get it from.
 			if ($row['is_array'] === TRUE)
 			{
@@ -454,7 +453,13 @@ public function run($group = '')
 			{
 				$this->_field_data[$field]['postdata'] = $validation_array[$field];
 			}
+		}
 
+		// Execute validation rules
+		// Note: A second foreach (for now) is required in order to avoid false-positives
+		//	 for rules like 'matches', which correlate to other validation fields.
+		foreach ($this->_field_data as $field => $row)
+		{
 			// Don't try to validate if we have no rules set
 			if (empty($row['rules']))
 			{

user_guide_src/source/libraries/form_validation.rst

@@ -910,9 +910,6 @@ Rule                      Parameter  Description
 	to two parameters, where at least one is required (to pass
 	the field data).
 
-.. note:: When using the **matches** rule, the form item specified
-	to compare against must already be defined.
-
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