MDL-12437, sorting by names adds teacher to gradebook list

grade/report/grader/lib.php

@@ -303,7 +303,8 @@ class grade_report_grader extends grade_report {
             } elseif ($this->sortitemid == 'firstname') {
                 $sort2 = ', u.lastname ' . $this->sortorder;
             }
-            $this->users = get_role_users($this->gradebookroles, $this->context, false,
+            $roles = explode(',', $this->gradebookroles);
+            $this->users = get_role_users($roles, $this->context, false,
                             'u.id, u.firstname, u.lastname', 'u.'.$this->sortitemid .' '. $this->sortorder . $sort2,
                             false, $this->currentgroup, $this->page * $this->get_pref('studentsperpage'), $this->get_pref('studentsperpage'));
 

lib/accesslib.php

@@ -4343,7 +4343,7 @@ function get_role_users($roleid, $context, $parent=false, $fields='', $sort='u.l
 
     if (is_array($roleid)) {
         $roleselect = ' AND ra.roleid IN (' . implode(',',$roleid) .')';
-    } elseif (is_int($roleid)) {
+    } elseif (!empty($roleid)) { // should not test for int, because it can come in as a string
         $roleselect = "AND ra.roleid = $roleid";
     } else {
         $roleselect = '';