Merge branch '3.1-stable' into develop

Resolved conflicts:
	system/core/CodeIgniter.php
	user_guide_src/source/changelog.rst
	user_guide_src/source/conf.py
	user_guide_src/source/installation/downloads.rst
	user_guide_src/source/installation/upgrading.rst
	user_guide_src/source/libraries/form_validation.rst

1 files changed, 21 insertions, 2 deletions

diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index e6ce13d81..66ed9ec8f 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -55,7 +55,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @var	string
  *
  */
-	define('CI_VERSION', '3.2.0-dev');
+	const CI_VERSION = '3.2.0-dev';
 
 /*
  * ------------------------------------------------------
@@ -416,10 +416,29 @@ if ( ! is_php('5.4'))
 			$params = array($method, array_slice($URI->rsegments, 2));
 			$method = '_remap';
 		}
-		elseif ( ! is_callable(array($class, $method)))
+		elseif ( ! method_exists($class, $method))
 		{
 			$e404 = TRUE;
 		}
+		/**
+		 * DO NOT CHANGE THIS, NOTHING ELSE WORKS!
+		 *
+		 * - method_exists() returns true for non-public methods, which passes the previous elseif
+		 * - is_callable() returns false for PHP 4-style constructors, even if there's a __construct()
+		 * - method_exists($class, '__construct') won't work because CI_Controller::__construct() is inherited
+		 * - People will only complain if this doesn't work, even though it is documented that it shouldn't.
+		 *
+		 * ReflectionMethod::isConstructor() is the ONLY reliable check,
+		 * knowing which method will be executed as a constructor.
+		 */
+		elseif ( ! is_callable(array($class, $method)) && strcasecmp($class, $method) === 0)
+		{
+			$reflection = new ReflectionMethod($class, $method);
+			if ( ! $reflection->isPublic() OR $reflection->isConstructor())
+			{
+				$e404 = TRUE;
+			}
+		}
 	}
 
 	if ($e404)