From c2d88da70873808949d88eaed42e80012452bd9d Mon Sep 17 00:00:00 2001
From: martinlanghoff <martinlanghoff>
Date: Fri, 25 Jan 2008 00:53:01 +0000
Subject: [PATCH] accesslib: Fix get_context_users_bycap() when no roles grant
 the cap

When no roles mention the capability, get_context_users_bycap() breaks
badly. This trivial patch does a sanity check before jumping into the
SQL shark-pool...

MDL-13160
---
 lib/accesslib.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/accesslib.php b/lib/accesslib.php
index b2a061336b..51d2f2d293 100755
--- a/lib/accesslib.php
+++ b/lib/accesslib.php
@@ -1145,6 +1145,10 @@ function get_context_users_bycap ($context, $capability='moodle/course:view', $f
     rs_close($rs);
     $roles = implode(',', $roles);
 
+    if (empty($roles)) {
+        return array();
+    }
+
     //
     // User permissions subselect SQL
     //
-- 
2.39.5