Fix: can't read permissions with an external module in root directory

instead "custom" directory

htdocs/core/lib/functions2.lib.php

@@ -25,6 +25,44 @@
  */
 
 
+/**
+ * Return list of modules directories
+ *
+ * @param	string	$subdir		Sub directory (Example: '/mailings')
+ * @return	array				Array of directories that can contains module descriptors
+ */
+function dolGetModulesDirs($subdir='')
+{
+    global $conf;
+
+    $modulesdir=array();
+
+    foreach ($conf->file->dol_document_root as $type => $dirroot)
+    {
+        // Default core/modules dir
+        $modulesdir[$dirroot . '/core/modules'.$subdir.'/'] = $dirroot . '/core/modules'.$subdir.'/';
+
+        // Scan dir from external modules
+        $handle=@opendir($dirroot);
+        if (is_resource($handle))
+        {
+            while (($file = readdir($handle))!==false)
+            {
+                if (is_dir($dirroot.'/'.$file) && substr($file, 0, 1) <> '.' && substr($file, 0, 3) <> 'CVS' && $file != 'includes')
+                {
+                    if (is_dir($dirroot . '/' . $file . '/core/modules'.$subdir.'/'))
+                    {
+                        $modulesdir[$dirroot . '/' . $file . '/core/modules'.$subdir.'/'] = $dirroot . '/' . $file . '/core/modules'.$subdir.'/';
+                    }
+                }
+            }
+            closedir($handle);
+        }
+    }
+    return $modulesdir;
+}
+
+
 /**
  *  Try to guess default paper format according to language into $langs
  *