diff --git a/blocks/admin/block_admin.php b/blocks/admin/block_admin.php
index ebc31816ebe..b0b7c5f616d 100644
--- a/blocks/admin/block_admin.php
+++ b/blocks/admin/block_admin.php
@@ -164,10 +164,10 @@ class block_admin extends block_list {
 
         if (empty($course->metacourse) && ($course->id!==SITEID)) {
             if (has_capability('moodle/legacy:guest', $context, NULL, false)) {   // Are a guest now
-                $this->content->items[]='<a href="enrol.php?id='.$this->instance->pageid.'">'.get_string('enrolme', '', $course->shortname).'</a>';
+                $this->content->items[]='<a href="enrol.php?id='.$this->instance->pageid.'">'.get_string('enrolme', '', s($course->shortname)).'</a>';
                 $this->content->icons[]='<img src="'.$CFG->pixpath.'/i/user.gif" class="icon" alt="" />';
             } else if (has_capability('moodle/role:unassignself', $context, NULL, false)) {  // Have some role
-                $this->content->items[]='<a href="unenrol.php?id='.$this->instance->pageid.'">'.get_string('unenrolme', '', $course->shortname).'</a>';
+                $this->content->items[]='<a href="unenrol.php?id='.$this->instance->pageid.'">'.get_string('unenrolme', '', s($course->shortname)).'</a>';
                 $this->content->icons[]='<img src="'.$CFG->pixpath.'/i/user.gif" class="icon" alt="" />';
             }
         }
diff --git a/blocks/course_list/block_course_list.php b/blocks/course_list/block_course_list.php
index 3e9a2ba5db1..b68b5b6407e 100644
--- a/blocks/course_list/block_course_list.php
+++ b/blocks/course_list/block_course_list.php
@@ -44,8 +44,8 @@ class block_course_list extends block_list {
                         continue;
                     }
                     $linkcss = $course->visible ? "" : " class=\"dimmed\" ";
-                    $this->content->items[]="<a $linkcss title=\"$course->shortname\" ".
-                               "href=\"$CFG->wwwroot/course/view.php?id=$course->id\">$course->fullname</a>";
+                    $this->content->items[]="<a $linkcss title=\"" . s($course->shortname) . "\" ".
+                               "href=\"$CFG->wwwroot/course/view.php?id=$course->id\">" . s($course->fullname) . "</a>";
                     $this->content->icons[]=$icon;
                 }
                 $this->title = get_string('mycourses');
@@ -62,7 +62,7 @@ class block_course_list extends block_list {
             if (count($categories) > 1 || (count($categories) == 1 && count_records('course') > 200)) {     // Just print top level category links
                 foreach ($categories as $category) {
                     $linkcss = $category->visible ? "" : " class=\"dimmed\" ";
-                    $this->content->items[]="<a $linkcss href=\"$CFG->wwwroot/course/category.php?id=$category->id\">$category->name</a>";
+                    $this->content->items[]="<a $linkcss href=\"$CFG->wwwroot/course/category.php?id=$category->id\">" . s($category->name) . "</a>";
                     $this->content->icons[]=$icon;
                 }
                 $this->content->icons[] = '';
@@ -77,7 +77,7 @@ class block_course_list extends block_list {
                 if ($courses) {
                     foreach ($courses as $course) {
                         $linkcss = $course->visible ? "" : " class=\"dimmed\" ";
-                        $this->content->items[]="<a $linkcss title=\"$course->shortname\" ".
+                        $this->content->items[]="<a $linkcss title=\"".s($course->shortname)."\" ".
                                    "href=\"$CFG->wwwroot/course/view.php?id=$course->id\">$course->fullname</a>";
                         $this->content->icons[]=$icon;
                     }
diff --git a/course/index.php b/course/index.php
index 8e63f08ef16..b45ba8a409d 100644
--- a/course/index.php
+++ b/course/index.php
@@ -106,9 +106,9 @@
             $newcategory->name = $form->addcategory;
             $newcategory->sortorder = 999;
             if (!insert_record('course_categories', $newcategory)) {
-                notify("Could not insert the new category '$newcategory->name'");
+                notify("Could not insert the new category '" . s($newcategory->name) . "'");
             } else {
-                notify(get_string('categoryadded', '', $newcategory->name));
+                notify(get_string('categoryadded', '', s($newcategory->name)));
             }
         }
     }
@@ -145,11 +145,11 @@
                 
                 /// Finally delete the category itself
                 if (delete_records('course_categories', 'id', $deletecat->id)) {
-                    notify(get_string('categorydeleted', '', $deletecat->name));
+                    notify(get_string('categorydeleted', '', s($deletecat->name)));
                 }
             }
             else {
-                $strdeletecategorycheck = get_string('deletecategorycheck','',$deletecat->name);
+                $strdeletecategorycheck = get_string('deletecategorycheck','', s($deletecat->name));
                 notice_yesno($strdeletecategorycheck,
                              "index.php?delete=$delete&amp;sure=".md5($deletecat->timemodified)."&amp;sesskey=$USER->sesskey",
                              "index.php?sesskey=$USER->sesskey");
@@ -353,7 +353,7 @@ function print_category_edit($category, $displaylist, $parentslist, $depth=-1, $
         $linkcss = $category->visible ? '' : ' class="dimmed" ';
         echo '<a '.$linkcss.' title="'.$str->edit.'" '.
              ' href="category.php?id='.$category->id.'&amp;categoryedit=on&amp;sesskey='.sesskey().'">'.
-             $category->name.'</a>';
+             s($category->name).'</a>';
         echo '</td>';
 
         echo '<td class="count">'.$category->coursecount.'</td>';
diff --git a/course/lib.php b/course/lib.php
index 31237089884..d023cf7ceaa 100644
--- a/course/lib.php
+++ b/course/lib.php
@@ -1454,7 +1454,7 @@ function print_section_add_menus($course, $section, $modnames, $vertical=false,
 
     // check to see if user can add menus
     if (!has_capability('moodle/course:manageactivities', get_context_instance(CONTEXT_COURSE, $course->id))) {
-        return false;  
+        return false;
     }
 
     static $resources = false;
@@ -1557,9 +1557,9 @@ function make_categories_list(&$list, &$parents, $category=NULL, $path="") {
 
     if ($category) {
         if ($path) {
-            $path = $path.' / '.$category->name;
+            $path = $path.' / '.s($category->name);
         } else {
-            $path = $category->name;
+            $path = s($category->name);
         }
         $list[$category->id] = $path;
     } else {
@@ -2208,7 +2208,7 @@ function make_editing_buttons($mod, $absolute=false, $moveselect=true, $indent=-
     $modcontext = get_context_instance(CONTEXT_MODULE, $mod->id);
     // no permission to edit
     if (!has_capability('moodle/course:manageactivities', $modcontext)) {
-        return false;  
+        return false;
     }
 
     if (!isset($str)) {
@@ -2284,7 +2284,7 @@ function make_editing_buttons($mod, $absolute=false, $moveselect=true, $indent=-
     } else {
         $groupmode = "";
     }
-    
+
     if (has_capability('moodle/course:update', get_context_instance(CONTEXT_COURSE, $mod->course))) {
         if ($moveselect) {
             $move =     '<a class="editing_move" title="'.$str->move.'" href="'.$path.'/mod.php?copy='.$mod->id.
diff --git a/lib/weblib.php b/lib/weblib.php
index aee0e4ba462..9a12f908e3a 100644
--- a/lib/weblib.php
+++ b/lib/weblib.php
@@ -109,17 +109,25 @@ $ALLOWED_PROTOCOLS = array('http', 'https', 'ftp', 'news', 'mailto', 'rtsp', 'te
  *                true should be used to print data from forms and false for data from DB.
  * @return string
  */
-function s($var, $strip=false) {
+function s($var, $strip=false, $specialchars=true) {
 
     if ($var == '0') {  // for integer 0, boolean false, string '0'
         return '0';
     }
 
+    $newvar = $var;
+
     if ($strip) {
-        return preg_replace("/&amp;(#\d+);/i", "&$1;", htmlspecialchars(stripslashes_safe($var)));
-    } else {
-        return preg_replace("/&amp;(#\d+);/i", "&$1;", htmlspecialchars($var));
+        $newvar = stripslashes_safe($newvar);
     }
+
+    if ($specialchars) {
+        $newvar = htmlspecialchars($newvar);
+    }
+
+    // Any lonely ampersands left, convert them using negative lookahead
+    $newvar = preg_replace("/\&(?!amp;|gt;|lt;|quot;)([^&]*)/", "&amp;$1", $newvar);
+    return $newvar;
 }
 
 /**
@@ -141,6 +149,8 @@ function p($var, $strip=false) {
  * Does proper javascript quoting.
  * Do not use addslashes anymore, because it does not work when magic_quotes_sybase is enabled.
  *
+ * @deprecated
+ * @since 1.8 - 22/02/2007
  * @param mixed value
  * @return mixed quoted result
  */
@@ -2184,6 +2194,7 @@ function print_header ($title='', $heading='', $navigation='', $focus='',
     $bodytags .= ' class="'.$pageclass.'" id="'.$pageid.'"';
 
     ob_start();
+    $title = s($title); // fix for MDL-8582
     include($CFG->header);
     $output = ob_get_contents();
     ob_end_clean();
@@ -2278,10 +2289,10 @@ function print_header_simple($title='', $heading='', $navigation='', $focus='',
 
     $shortname ='';
     if ($COURSE->id != SITEID) {
-        $shortname = '<a href="'.$CFG->wwwroot.'/course/view.php?id='. $COURSE->id .'">'. $COURSE->shortname .'</a> ->';
+        $shortname = '<a href="'.$CFG->wwwroot.'/course/view.php?id='. $COURSE->id .'">'. s($COURSE->shortname) .'</a> ->';
     }
 
-    $output = print_header($COURSE->shortname .': '. $title, $COURSE->fullname .' '. $heading, $shortname .' '. $navigation, $focus, $meta,
+    $output = print_header(s($COURSE->shortname) .': '. s($title), s($COURSE->fullname) .' '. s($heading), $shortname.' '. $navigation, $focus, $meta,
                            $cache, $button, $menu, $usexml, $bodytags, true);
 
     if ($return) {
@@ -2319,7 +2330,7 @@ function print_footer($course=NULL, $usercourse=NULL, $return=false) {
             $home  = true;
         } else {
             $homelink = '<div class="homelink"><a '.$CFG->frametarget.' href="'.$CFG->wwwroot.
-                        '/course/view.php?id='.$course->id.'">'.$course->shortname.'</a></div>';
+                        '/course/view.php?id='.$course->id.'">'.s($course->shortname).'</a></div>';
             $home  = false;
         }
     } else {
@@ -2780,9 +2791,10 @@ function print_navigation ($navigation, $separator=0, $return=false) {
         if (! $site = get_site()) {
             $site->shortname = get_string('home');
         }
-        $navigation = "<li>$separator ". str_replace('->', "</li>\n<li>$separator", $navigation) ."</li>\n";
+
+        $navigation = "<li>$separator ". str_replace('->', "</li>\n<li>$separator", s($navigation, false, false)) ."</li>\n";
         $output .= '<li class="first"><a '.$CFG->frametarget.' onclick="this.target=\''.$CFG->framename.'\'" href="'. $CFG->wwwroot.((!has_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM, SITEID)) && !empty($USER->id) && !empty($CFG->mymoodleredirect) && !isguest())
-                                                                       ? '/my' : '') .'/">'. $site->shortname ."</a></li>\n". $navigation;
+                                                                       ? '/my' : '') .'/">'. s($site->shortname) ."</a></li>\n". $navigation;
         $output .= "</ul>\n";
     }