Simplification of return types. No need to return more mixed than necessary.

lib/Cake/Controller/Component/SecurityComponent.php

@@ -355,7 +355,7 @@ class SecurityComponent extends Component {
  * Check if HTTP methods are required
  *
  * @param Controller $controller Instantiating controller
- * @return bool|null True if $method is required
+ * @return bool True if $method is required
  */
 	protected function _methodsRequired(Controller $controller) {
 		foreach (array('Post', 'Get', 'Put', 'Delete') as $method) {
@@ -365,7 +365,7 @@ class SecurityComponent extends Component {
 				if (in_array($this->_action, $require) || $this->$property === array('*')) {
 					if (!$this->request->is($method)) {
 						if (!$this->blackHole($controller, $method)) {
-							return null;
+							return false;
 						}
 					}
 				}
@@ -378,7 +378,7 @@ class SecurityComponent extends Component {
  * Check if access requires secure connection
  *
  * @param Controller $controller Instantiating controller
- * @return bool|null True if secure connection required
+ * @return bool True if secure connection required
  */
 	protected function _secureRequired(Controller $controller) {
 		if (is_array($this->requireSecure) && !empty($this->requireSecure)) {
@@ -387,7 +387,7 @@ class SecurityComponent extends Component {
 			if (in_array($this->_action, $requireSecure) || $this->requireSecure === array('*')) {
 				if (!$this->request->is('ssl')) {
 					if (!$this->blackHole($controller, 'secure')) {
-						return null;
+						return false;
 					}
 				}
 			}

lib/Cake/I18n/Multibyte.php

@@ -824,14 +824,14 @@ class Multibyte {
  *
  * @param int $char decimal value of character
  * @param string $type Type 'lower' or 'upper'. Defaults to 'lower'.
- * @return array|null
+ * @return array
  */
 	protected static function _find($char, $type = 'lower') {
 		$found = array();
 		if (!isset(self::$_codeRange[$char])) {
 			$range = self::_codepoint($char);
 			if ($range === false) {
-				return null;
+				return array();
 			}
 			if (!Configure::configured('_cake_core_')) {
 				App::uses('PhpReader', 'Configure');
@@ -843,7 +843,7 @@ class Multibyte {
 		}
 
 		if (!self::$_codeRange[$char]) {
-			return null;
+			return array();
 		}
 		self::$_table = self::$_codeRange[$char];
 		$count = count(self::$_caseFold[self::$_table]);

lib/Cake/Model/Behavior/AclBehavior.php

@@ -73,7 +73,7 @@ class AclBehavior extends ModelBehavior {
  * @param Model $model Model using this behavior.
  * @param string|array|Model $ref Array with 'model' and 'foreign_key', model object, or string value
  * @param string $type Only needed when Acl is set up as 'both', specify 'Aro' or 'Aco' to get the correct node
- * @return array|null
+ * @return array
  * @link http://book.cakephp.org/2.0/en/core-libraries/behaviors/acl.html#node
  */
 	public function node(Model $model, $ref = null, $type = null) {
@@ -81,7 +81,7 @@ class AclBehavior extends ModelBehavior {
 			$type = $this->_typeMaps[$this->settings[$model->name]['type']];
 			if (is_array($type)) {
 				trigger_error(__d('cake_dev', 'AclBehavior is setup with more then one type, please specify type parameter for node()'), E_USER_WARNING);
-				return null;
+				return array();
 			}
 		}
 		if (empty($ref)) {

lib/Cake/Model/Behavior/TreeBehavior.php

@@ -443,7 +443,7 @@ class TreeBehavior extends ModelBehavior {
  * @param int|string $id The ID of the record to read
  * @param string|array $fields Either a single string of a field name, or an array of field names
  * @param int $recursive The number of levels deep to fetch associated records
- * @return array|null Array of nodes from top most parent to current node
+ * @return array Array of nodes from top most parent to current node
  * @link http://book.cakephp.org/2.0/en/core-libraries/behaviors/tree.html#TreeBehavior::getPath
  */
 	public function getPath(Model $Model, $id = null, $fields = null, $recursive = null) {
@@ -462,7 +462,7 @@ class TreeBehavior extends ModelBehavior {
 		if ($result) {
 			$result = array_values($result);
 		} else {
-			return null;
+			return array();
 		}
 		$item = $result[0];
 		$results = $Model->find('all', array(

lib/Cake/Routing/Router.php

@@ -731,7 +731,7 @@ class Router {
  *
  * @param string $name Parameter name
  * @param bool $current Current parameter, useful when using requestAction
- * @return string Parameter value
+ * @return string|null Parameter value
  */
 	public static function getParam($name = 'controller', $current = false) {
 		$params = Router::getParams($current);

lib/Cake/Test/Case/View/Helper/PaginatorHelperTest.php

@@ -2731,9 +2731,9 @@ class PaginatorHelperTest extends CakeTestCase {
 				'paramType' => 'named',
 			)
 		);
-		$this->assertFalse($this->Paginator->numbers());
-		$this->assertFalse($this->Paginator->first());
-		$this->assertFalse($this->Paginator->last());
+		$this->assertSame('', $this->Paginator->numbers());
+		$this->assertSame('', $this->Paginator->first());
+		$this->assertSame('', $this->Paginator->last());
 	}
 
 /**

lib/Cake/Utility/Folder.php

@@ -604,7 +604,7 @@ class Folder {
 			$path = $this->pwd();
 		}
 		if (!$path) {
-			return null;
+			return false;
 		}
 		$path = Folder::slashTerm($path);
 		if (is_dir($path)) {

lib/Cake/View/Helper/FormHelper.php

@@ -696,7 +696,7 @@ class FormHelper extends AppHelper {
  * @param string|array $text Error message as string or array of messages.
  *   If array contains `attributes` key it will be used as options for error container
  * @param array $options Rendering options for <div /> wrapper tag
- * @return string If there are errors this method returns an error message, otherwise null.
+ * @return string|null If there are errors this method returns an error message, otherwise null.
  * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/form.html#FormHelper::error
  */
 	public function error($field, $text = null, $options = array()) {

lib/Cake/View/Helper/PaginatorHelper.php

@@ -481,7 +481,7 @@ class PaginatorHelper extends AppHelper {
  * @param array $options Options list.
  * @param string $disabledTitle Disabled link title.
  * @param array $disabledOptions Disabled link options.
- * @return string|null
+ * @return string
  */
 	protected function _pagingLink($which, $title = null, $options = array(), $disabledTitle = null, $disabledOptions = array()) {
 		$check = 'has' . $which;
@@ -501,7 +501,7 @@ class PaginatorHelper extends AppHelper {
 			}
 			$options = (array)$disabledOptions + $_defaults;
 		} elseif (!$this->{$check}($options['model'])) {
-			return null;
+			return '';
 		}
 
 		foreach (array_keys($_defaults) as $key) {
@@ -707,7 +707,7 @@ class PaginatorHelper extends AppHelper {
  * - `currentTag` Tag to use for current page number, defaults to null
  *
  * @param array $options Options for the numbers, (before, after, model, modulus, separator)
- * @return string|bool numbers string.
+ * @return string Numbers string.
  * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/paginator.html#PaginatorHelper::numbers
  */
 	public function numbers($options = array()) {
@@ -728,7 +728,7 @@ class PaginatorHelper extends AppHelper {
 		unset($options['model']);
 
 		if ($params['pageCount'] <= 1) {
-			return false;
+			return '';
 		}
 
 		extract($options);
@@ -849,7 +849,7 @@ class PaginatorHelper extends AppHelper {
  * @param string|int $first if string use as label for the link. If numeric, the number of page links
  *   you want at the beginning of the range.
  * @param array $options An array of options.
- * @return string|bool numbers string.
+ * @return string Numbers string.
  * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/paginator.html#PaginatorHelper::first
  */
 	public function first($first = '<< first', $options = array()) {
@@ -866,7 +866,7 @@ class PaginatorHelper extends AppHelper {
 		unset($options['model']);
 
 		if ($params['pageCount'] <= 1) {
-			return false;
+			return '';
 		}
 		extract($options);
 		unset($options['tag'], $options['after'], $options['model'], $options['separator'], $options['ellipsis'], $options['class']);
@@ -912,7 +912,7 @@ class PaginatorHelper extends AppHelper {
  *
  * @param string|int $last if string use as label for the link, if numeric print page numbers
  * @param array $options Array of options
- * @return string|bool numbers string.
+ * @return string Numbers string.
  * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/paginator.html#PaginatorHelper::last
  */
 	public function last($last = 'last >>', $options = array()) {
@@ -929,7 +929,7 @@ class PaginatorHelper extends AppHelper {
 		unset($options['model']);
 
 		if ($params['pageCount'] <= 1) {
-			return false;
+			return '';
 		}
 
 		extract($options);
@@ -976,7 +976,7 @@ class PaginatorHelper extends AppHelper {
  * - `block` The block name to append the output to, or false/absenst to return as a string
  *
  * @param array $options Array of options
- * @return string|null Meta links
+ * @return string|void Meta links
  */
 	public function meta($options = array()) {
 		$model = isset($options['model']) ? $options['model'] : null;