diff --git a/admin/tool/xmldb/actions/XMLDBAction.class.php b/admin/tool/xmldb/actions/XMLDBAction.class.php
index b853a7e631d..d984894fabf 100644
--- a/admin/tool/xmldb/actions/XMLDBAction.class.php
+++ b/admin/tool/xmldb/actions/XMLDBAction.class.php
@@ -54,18 +54,11 @@ class XMLDBAction {
 
     var $sesskey_protected; // Actions must be protected by sesskey mechanism
 
-    /**
-     * Constructor
-     */
-    function XMLDBAction() {
-        $this->init();
-    }
-
     /**
      * Constructor to keep PHP5 happy
      */
     function __construct() {
-        $this->XMLDBAction();
+        $this->init();
     }
 
     /**
diff --git a/auth/cas/auth.php b/auth/cas/auth.php
index fa6fb0f6147..d8c95231ffb 100644
--- a/auth/cas/auth.php
+++ b/auth/cas/auth.php
@@ -215,7 +215,7 @@ class auth_plugin_cas extends auth_plugin_ldap {
      * @param object object with submitted configuration settings (without system magic quotes)
      * @param array $err array of error messages
      */
-    function validate_form(&$form, &$err) {
+    function validate_form($form, &$err) {
         $certificate_path = trim($form->certificate_path);
         if ($form->certificate_check && empty($certificate_path)) {
             $err['certificate_path'] = get_string('auth_cas_certificate_path_empty', 'auth_cas');
diff --git a/grade/edit/tree/lib.php b/grade/edit/tree/lib.php
index 605783147fa..5a268b40c0f 100644
--- a/grade/edit/tree/lib.php
+++ b/grade/edit/tree/lib.php
@@ -355,7 +355,7 @@ class grade_edit_tree {
      * @param string type "extra" or "weight": the type of the column hosting the weight input
      * @return string HTML
      */
-    function get_weight_input($item, $type) {
+    static function get_weight_input($item, $type) {
         global $OUTPUT;
 
         if (!is_object($item) || get_class($item) !== 'grade_item') {
@@ -387,7 +387,7 @@ class grade_edit_tree {
     //Trims trailing zeros
     //Used on the 'categories and items' page for grade items settings like aggregation co-efficient
     //Grader report has its own decimal place settings so they are handled elsewhere
-    function format_number($number) {
+    static function format_number($number) {
         $formatted = rtrim(format_float($number, 4),'0');
         if (substr($formatted, -1)=='.') { //if last char is the decimal point
             $formatted .= '0';
diff --git a/grade/report/grader/lib.php b/grade/report/grader/lib.php
index eca29e3f5d1..3ec4d7a7405 100644
--- a/grade/report/grader/lib.php
+++ b/grade/report/grader/lib.php
@@ -1207,7 +1207,7 @@ class grade_report_grader extends grade_report {
 
             foreach ($this->gtree->items as $itemid=>$unused) {
                 // emulate grade element
-                $item =& $this->gtree->get_item($itemid);
+                $item = $this->gtree->get_item($itemid);
 
                 $eid = $this->gtree->get_item_eid($item);
                 $element = $this->gtree->locate_element($eid);
diff --git a/lib/authlib.php b/lib/authlib.php
index 334bd44b542..7bb1d17324f 100644
--- a/lib/authlib.php
+++ b/lib/authlib.php
@@ -366,7 +366,7 @@ class auth_plugin_base {
      * @param object object with submitted configuration settings (without system magic quotes)
      * @param array $err array of error messages
      */
-     function validate_form(&$form, &$err) {
+     function validate_form($form, &$err) {
         //override if needed
     }
 
diff --git a/lib/cronlib.php b/lib/cronlib.php
index 11c3def5f86..818a774bdc4 100644
--- a/lib/cronlib.php
+++ b/lib/cronlib.php
@@ -356,7 +356,7 @@ function cron_run() {
         require_once($CFG->dirroot . '/blog/lib.php');
         mtrace("Fetching external blog entries...", '');
         $sql = "timefetched < ? OR timefetched = 0";
-        $externalblogs = $DB->get_records_select('blog_external', $sql, array(mktime() - $CFG->externalblogcrontime));
+        $externalblogs = $DB->get_records_select('blog_external', $sql, array(time() - $CFG->externalblogcrontime));
 
         foreach ($externalblogs as $eb) {
             blog_sync_external_entries($eb);
diff --git a/lib/form/dateselector.php b/lib/form/dateselector.php
index 5b36e4e2d09..969b11c4dc6 100644
--- a/lib/form/dateselector.php
+++ b/lib/form/dateselector.php
@@ -108,7 +108,7 @@ class MoodleQuickForm_date_selector extends MoodleQuickForm_group
         $this->_elements[] = @MoodleQuickForm::createElement('select', 'year', get_string('year', 'form'), $years, $this->getAttributes(), true);
         // If optional we add a checkbox which the user can use to turn if on
         if($this->_options['optional']) {
-            $this->_elements[] =& MoodleQuickForm::createElement('checkbox', 'enabled', null, get_string('enable'), $this->getAttributes(), true);
+            $this->_elements[] =@MoodleQuickForm::createElement('checkbox', 'enabled', null, get_string('enable'), $this->getAttributes(), true);
         }
         foreach ($this->_elements as $element){
             if (method_exists($element, 'setHiddenLabel')){
diff --git a/lib/grade/grade_category.php b/lib/grade/grade_category.php
index 97a78f74c86..ca67450c4ab 100644
--- a/lib/grade/grade_category.php
+++ b/lib/grade/grade_category.php
@@ -1011,7 +1011,8 @@ class grade_category extends grade_object {
                                 'children'=>$course_category->get_children($include_category_items));
 
         $course_category->sortorder = $course_category->get_sortorder();
-        return grade_category::_fetch_course_tree_recursion($category_array, $course_category->get_sortorder());
+        $sortorder = $course_category->get_sortorder();
+        return grade_category::_fetch_course_tree_recursion($category_array, $sortorder);
     }
 
     /**
diff --git a/question/category_class.php b/question/category_class.php
index 07c2d91be93..96b5efa32ab 100644
--- a/question/category_class.php
+++ b/question/category_class.php
@@ -73,7 +73,7 @@ class question_category_list extends moodle_list {
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class question_category_list_item extends list_item {
-    public function set_icon_html($first, $last, &$lastitem){
+    public function set_icon_html($first, $last, $lastitem){
         global $CFG;
         $category = $this->item;
         $url = new moodle_url('/question/category.php', ($this->parentlist->pageurl->params() + array('edit'=>$category->id)));
@@ -155,6 +155,7 @@ class question_category_object {
 
         $this->tab = str_repeat('&nbsp;', $this->tabsize);
 
+        $this->str = new stdClass();
         $this->str->course         = get_string('course');
         $this->str->category       = get_string('category', 'question');
         $this->str->categoryinfo   = get_string('categoryinfo', 'question');
diff --git a/question/format/aiken/format.php b/question/format/aiken/format.php
index 4e64c2f6a93..06afee43e8f 100644
--- a/question/format/aiken/format.php
+++ b/question/format/aiken/format.php
@@ -58,7 +58,7 @@ class qformat_aiken extends qformat_default {
         return true;
     }
 
-    public function readquestions($lines) {
+    public function readquestions($lines, $context) {
         $questions = array();
         $question = $this->defaultquestion();
         $endchar = chr(13);
diff --git a/question/format/blackboard/format.php b/question/format/blackboard/format.php
index 1abf61f6cef..015c903782e 100644
--- a/question/format/blackboard/format.php
+++ b/question/format/blackboard/format.php
@@ -41,7 +41,7 @@ class qformat_blackboard extends qformat_default {
         return true;
     }
 
-    function readquestions ($lines) {
+    function readquestions ($lines, $context) {
         /// Parses an array of lines into an array of questions,
         /// where each item is a question object as defined by
         /// readquestion().
diff --git a/question/format/blackboard_six/format.php b/question/format/blackboard_six/format.php
index 08614d3f024..4c996231864 100644
--- a/question/format/blackboard_six/format.php
+++ b/question/format/blackboard_six/format.php
@@ -243,7 +243,7 @@ class qformat_blackboard_six extends qformat_default {
 
 
 
-  function readquestions ($lines) {
+  protected function readquestions ($lines, $context) {
     /// Parses an array of lines into an array of questions,
     /// where each item is a question object as defined by
     /// readquestion().
diff --git a/question/format/examview/format.php b/question/format/examview/format.php
index 53bb360fcf3..ba51cbc0c0c 100644
--- a/question/format/examview/format.php
+++ b/question/format/examview/format.php
@@ -149,7 +149,7 @@ class qformat_examview extends qformat_default {
         return str_replace('&#x2019;', "'", $text);
     }
 
-    function readquestions($lines) {
+    protected function readquestions($lines, $context) {
         /// Parses an array of lines into an array of questions,
         /// where each item is a question object as defined by
         /// readquestion().
diff --git a/question/format/learnwise/format.php b/question/format/learnwise/format.php
index a27e86f1e00..d625ae8b7bb 100644
--- a/question/format/learnwise/format.php
+++ b/question/format/learnwise/format.php
@@ -46,7 +46,7 @@ class qformat_learnwise extends qformat_default {
         return true;
     }
 
-    function readquestions($lines) {
+    protected function readquestions($lines, $context) {
         $questions = array();
         $currentquestion = array();
 
diff --git a/question/format/multianswer/format.php b/question/format/multianswer/format.php
index 45179d8d9f6..d8a94045404 100644
--- a/question/format/multianswer/format.php
+++ b/question/format/multianswer/format.php
@@ -40,7 +40,7 @@ class qformat_multianswer extends qformat_default {
       return true;
     }
 
-    protected function readquestions($lines) {
+    protected function readquestions($lines, $context) {
         // For this class the method has been simplified as
         // there can never be more than one question for a
         // multianswer import
diff --git a/question/format/webct/format.php b/question/format/webct/format.php
index db833a0bf8c..b00063f56d9 100644
--- a/question/format/webct/format.php
+++ b/question/format/webct/format.php
@@ -172,7 +172,7 @@ class qformat_webct extends qformat_default {
       return true;
     }
 
-    function readquestions ($lines) {
+    protected function readquestions($lines, $context) {
         $webctnumberregex =
                 '[+-]?([0-9]+(\\.[0-9]*)?|\\.[0-9]+)((e|E|\\*10\\*\\*)([+-]?[0-9]+|\\([+-]?[0-9]+\\)))?';
 
diff --git a/question/format/xml/format.php b/question/format/xml/format.php
index 2633deba953..d7508641ca9 100644
--- a/question/format/xml/format.php
+++ b/question/format/xml/format.php
@@ -886,9 +886,10 @@ class qformat_xml extends qformat_default {
      * this *could* burn memory - but it won't happen that much
      * so fingers crossed!
      * @param array of lines from the input file.
+     * @param stdClass $context
      * @return array (of objects) question objects.
      */
-    protected function readquestions($lines) {
+    protected function readquestions($lines, $context) {
         // We just need it as one big string
         $text = implode($lines, ' ');
         unset($lines);