From c30b5812d1628c22789f5673a1f690d22c60d998 Mon Sep 17 00:00:00 2001
From: Ingo Schommer <ingo@silverstripe.com>
Date: Fri, 7 Nov 2008 12:09:39 +0000
Subject: [PATCH] API CHANGE Don't include NULL returns in decorated methods
 called through Object->extend(), meaning empty method bodies in decorators
 won't confuse permission checks through $myObj->extend('canView') etc.

git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@65451 467b73ca-7a2a-4603-9d3b-597d59a354a9
---
 core/Object.php | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/core/Object.php b/core/Object.php
index de329be62..955f79b6d 100755
--- a/core/Object.php
+++ b/core/Object.php
@@ -459,19 +459,24 @@ class Object {
 	 * originally returned void, so if you wanted to return results, you're hosed.
 	 * 
 	 * Currently returns an array, with an index resulting every time the function is called.
+	 * Only adds returns if they're not NULL, to avoid bogus results from methods just
+	 * defined on the parent decorator. This is important for permission-checks through
+	 * extend, as they use min() to determine if any of the returns is FALSE.
+	 * As min() doesn't do type checking, an included NULL return would fail the permission checks.
 	 * 
 	 * @param string $funcName The name of the function.
 	 * @param mixed $arg An Argument to be passed to each of the extension functions.
 	 */
 	public function extend($funcName, &$arg=null) {
 		if($this->extension_instances) {
-			$return = array();
+			$returnArr = array();
 			foreach($this->extension_instances as $extension) {
 				if($extension->hasMethod($funcName)) {
-					$return[] = $extension->$funcName($arg);
+					$return = $extension->$funcName($arg);
+					if($return !== NULL) $returnArr[] = $return;
 				}
 			}
-			return $return;
+			return $returnArr;
 		}
 	}