htmlpurifier update - compatibility issue with language library autoloader

42 files changed, 1462 insertions, 513 deletions

diff --git a/library/HTMLPurifier/AttrDef/CSS.php b/library/HTMLPurifier/AttrDef/CSS.php
index 953e70675..02c1641fb 100644
--- a/library/HTMLPurifier/AttrDef/CSS.php
+++ b/library/HTMLPurifier/AttrDef/CSS.php
@@ -14,8 +14,14 @@
 class HTMLPurifier_AttrDef_CSS extends HTMLPurifier_AttrDef
 {
 
-    public function validate($css, $config, $context) {
-
+    /**
+     * @param string $css
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($css, $config, $context)
+    {
         $css = $this->parseCDATA($css);
 
         $definition = $config->getCSSDefinition();
@@ -36,34 +42,47 @@ class HTMLPurifier_AttrDef_CSS extends HTMLPurifier_AttrDef
         $context->register('CurrentCSSProperty', $property);
 
         foreach ($declarations as $declaration) {
-            if (!$declaration) continue;
-            if (!strpos($declaration, ':')) continue;
+            if (!$declaration) {
+                continue;
+            }
+            if (!strpos($declaration, ':')) {
+                continue;
+            }
             list($property, $value) = explode(':', $declaration, 2);
             $property = trim($property);
-            $value    = trim($value);
+            $value = trim($value);
             $ok = false;
             do {
                 if (isset($definition->info[$property])) {
                     $ok = true;
                     break;
                 }
-                if (ctype_lower($property)) break;
+                if (ctype_lower($property)) {
+                    break;
+                }
                 $property = strtolower($property);
                 if (isset($definition->info[$property])) {
                     $ok = true;
                     break;
                 }
-            } while(0);
-            if (!$ok) continue;
+            } while (0);
+            if (!$ok) {
+                continue;
+            }
             // inefficient call, since the validator will do this again
             if (strtolower(trim($value)) !== 'inherit') {
                 // inherit works for everything (but only on the base property)
                 $result = $definition->info[$property]->validate(
-                    $value, $config, $context );
+                    $value,
+                    $config,
+                    $context
+                );
             } else {
                 $result = 'inherit';
             }
-            if ($result === false) continue;
+            if ($result === false) {
+                continue;
+            }
             $propvalues[$property] = $result;
         }
 
diff --git a/library/HTMLPurifier/AttrDef/CSS/AlphaValue.php b/library/HTMLPurifier/AttrDef/CSS/AlphaValue.php
index 292c040d4..af2b83dff 100644
--- a/library/HTMLPurifier/AttrDef/CSS/AlphaValue.php
+++ b/library/HTMLPurifier/AttrDef/CSS/AlphaValue.php
@@ -3,19 +3,32 @@
 class HTMLPurifier_AttrDef_CSS_AlphaValue extends HTMLPurifier_AttrDef_CSS_Number
 {
 
-    public function __construct() {
+    public function __construct()
+    {
         parent::__construct(false); // opacity is non-negative, but we will clamp it
     }
 
-    public function validate($number, $config, $context) {
+    /**
+     * @param string $number
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return string
+     */
+    public function validate($number, $config, $context)
+    {
         $result = parent::validate($number, $config, $context);
-        if ($result === false) return $result;
-        $float = (float) $result;
-        if ($float < 0.0) $result = '0';
-        if ($float > 1.0) $result = '1';
+        if ($result === false) {
+            return $result;
+        }
+        $float = (float)$result;
+        if ($float < 0.0) {
+            $result = '0';
+        }
+        if ($float > 1.0) {
+            $result = '1';
+        }
         return $result;
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/Background.php b/library/HTMLPurifier/AttrDef/CSS/Background.php
index 3a3d20cd6..7f1ea3b0f 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Background.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Background.php
@@ -9,11 +9,16 @@ class HTMLPurifier_AttrDef_CSS_Background extends HTMLPurifier_AttrDef
 
     /**
      * Local copy of component validators.
+     * @type HTMLPurifier_AttrDef[]
      * @note See HTMLPurifier_AttrDef_Font::$info for a similar impl.
      */
     protected $info;
 
-    public function __construct($config) {
+    /**
+     * @param HTMLPurifier_Config $config
+     */
+    public function __construct($config)
+    {
         $def = $config->getCSSDefinition();
         $this->info['background-color'] = $def->info['background-color'];
         $this->info['background-image'] = $def->info['background-image'];
@@ -22,40 +27,55 @@ class HTMLPurifier_AttrDef_CSS_Background extends HTMLPurifier_AttrDef
         $this->info['background-position'] = $def->info['background-position'];
     }
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         // regular pre-processing
         $string = $this->parseCDATA($string);
-        if ($string === '') return false;
+        if ($string === '') {
+            return false;
+        }
 
         // munge rgb() decl if necessary
         $string = $this->mungeRgb($string);
 
         // assumes URI doesn't have spaces in it
-        $bits = explode(' ', strtolower($string)); // bits to process
+        $bits = explode(' ', $string); // bits to process
 
         $caught = array();
-        $caught['color']    = false;
-        $caught['image']    = false;
-        $caught['repeat']   = false;
+        $caught['color'] = false;
+        $caught['image'] = false;
+        $caught['repeat'] = false;
         $caught['attachment'] = false;
         $caught['position'] = false;
 
         $i = 0; // number of catches
-        $none = false;
 
         foreach ($bits as $bit) {
-            if ($bit === '') continue;
+            if ($bit === '') {
+                continue;
+            }
             foreach ($caught as $key => $status) {
                 if ($key != 'position') {
-                    if ($status !== false) continue;
+                    if ($status !== false) {
+                        continue;
+                    }
                     $r = $this->info['background-' . $key]->validate($bit, $config, $context);
                 } else {
                     $r = $bit;
                 }
-                if ($r === false) continue;
+                if ($r === false) {
+                    continue;
+                }
                 if ($key == 'position') {
-                    if ($caught[$key] === false) $caught[$key] = '';
+                    if ($caught[$key] === false) {
+                        $caught[$key] = '';
+                    }
                     $caught[$key] .= $r . ' ';
                 } else {
                     $caught[$key] = $r;
@@ -65,7 +85,9 @@ class HTMLPurifier_AttrDef_CSS_Background extends HTMLPurifier_AttrDef
             }
         }
 
-        if (!$i) return false;
+        if (!$i) {
+            return false;
+        }
         if ($caught['position'] !== false) {
             $caught['position'] = $this->info['background-position']->
                 validate($caught['position'], $config, $context);
@@ -73,15 +95,17 @@ class HTMLPurifier_AttrDef_CSS_Background extends HTMLPurifier_AttrDef
 
         $ret = array();
         foreach ($caught as $value) {
-            if ($value === false) continue;
+            if ($value === false) {
+                continue;
+            }
             $ret[] = $value;
         }
 
-        if (empty($ret)) return false;
+        if (empty($ret)) {
+            return false;
+        }
         return implode(' ', $ret);
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/BackgroundPosition.php b/library/HTMLPurifier/AttrDef/CSS/BackgroundPosition.php
index fae82eaec..4580ef5a9 100644
--- a/library/HTMLPurifier/AttrDef/CSS/BackgroundPosition.php
+++ b/library/HTMLPurifier/AttrDef/CSS/BackgroundPosition.php
@@ -44,15 +44,30 @@
 class HTMLPurifier_AttrDef_CSS_BackgroundPosition extends HTMLPurifier_AttrDef
 {
 
+    /**
+     * @type HTMLPurifier_AttrDef_CSS_Length
+     */
     protected $length;
+
+    /**
+     * @type HTMLPurifier_AttrDef_CSS_Percentage
+     */
     protected $percentage;
 
-    public function __construct() {
-        $this->length     = new HTMLPurifier_AttrDef_CSS_Length();
+    public function __construct()
+    {
+        $this->length = new HTMLPurifier_AttrDef_CSS_Length();
         $this->percentage = new HTMLPurifier_AttrDef_CSS_Percentage();
     }
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = $this->parseCDATA($string);
         $bits = explode(' ', $string);
 
@@ -74,7 +89,9 @@ class HTMLPurifier_AttrDef_CSS_BackgroundPosition extends HTMLPurifier_AttrDef
         );
 
         foreach ($bits as $bit) {
-            if ($bit === '') continue;
+            if ($bit === '') {
+                continue;
+            }
 
             // test for keyword
             $lbit = ctype_lower($bit) ? $bit : strtolower($bit);
@@ -104,30 +121,37 @@ class HTMLPurifier_AttrDef_CSS_BackgroundPosition extends HTMLPurifier_AttrDef
                 $measures[] = $r;
                 $i++;
             }
-
         }
 
-        if (!$i) return false; // no valid values were caught
+        if (!$i) {
+            return false;
+        } // no valid values were caught
 
         $ret = array();
 
         // first keyword
-        if     ($keywords['h'])     $ret[] = $keywords['h'];
-        elseif ($keywords['ch']) {
+        if ($keywords['h']) {
+            $ret[] = $keywords['h'];
+        } elseif ($keywords['ch']) {
             $ret[] = $keywords['ch'];
             $keywords['cv'] = false; // prevent re-use: center = center center
+        } elseif (count($measures)) {
+            $ret[] = array_shift($measures);
         }
-        elseif (count($measures))   $ret[] = array_shift($measures);
 
-        if     ($keywords['v'])     $ret[] = $keywords['v'];
-        elseif ($keywords['cv'])    $ret[] = $keywords['cv'];
-        elseif (count($measures))   $ret[] = array_shift($measures);
+        if ($keywords['v']) {
+            $ret[] = $keywords['v'];
+        } elseif ($keywords['cv']) {
+            $ret[] = $keywords['cv'];
+        } elseif (count($measures)) {
+            $ret[] = array_shift($measures);
+        }
 
-        if (empty($ret)) return false;
+        if (empty($ret)) {
+            return false;
+        }
         return implode(' ', $ret);
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/Border.php b/library/HTMLPurifier/AttrDef/CSS/Border.php
index 42a1d1b4a..16243ba1e 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Border.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Border.php
@@ -8,17 +8,29 @@ class HTMLPurifier_AttrDef_CSS_Border extends HTMLPurifier_AttrDef
 
     /**
      * Local copy of properties this property is shorthand for.
+     * @type HTMLPurifier_AttrDef[]
      */
     protected $info = array();
 
-    public function __construct($config) {
+    /**
+     * @param HTMLPurifier_Config $config
+     */
+    public function __construct($config)
+    {
         $def = $config->getCSSDefinition();
         $this->info['border-width'] = $def->info['border-width'];
         $this->info['border-style'] = $def->info['border-style'];
         $this->info['border-top-color'] = $def->info['border-top-color'];
     }
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = $this->parseCDATA($string);
         $string = $this->mungeRgb($string);
         $bits = explode(' ', $string);
@@ -26,7 +38,9 @@ class HTMLPurifier_AttrDef_CSS_Border extends HTMLPurifier_AttrDef
         $ret = ''; // return value
         foreach ($bits as $bit) {
             foreach ($this->info as $propname => $validator) {
-                if (isset($done[$propname])) continue;
+                if (isset($done[$propname])) {
+                    continue;
+                }
                 $r = $validator->validate($bit, $config, $context);
                 if ($r !== false) {
                     $ret .= $r . ' ';
@@ -37,7 +51,6 @@ class HTMLPurifier_AttrDef_CSS_Border extends HTMLPurifier_AttrDef
         }
         return rtrim($ret);
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/Color.php b/library/HTMLPurifier/AttrDef/CSS/Color.php
index 07f95a671..16d2a6b98 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Color.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Color.php
@@ -6,29 +6,47 @@
 class HTMLPurifier_AttrDef_CSS_Color extends HTMLPurifier_AttrDef
 {
 
-    public function validate($color, $config, $context) {
-
+    /**
+     * @param string $color
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($color, $config, $context)
+    {
         static $colors = null;
-        if ($colors === null) $colors = $config->get('Core.ColorKeywords');
+        if ($colors === null) {
+            $colors = $config->get('Core.ColorKeywords');
+        }
 
         $color = trim($color);
-        if ($color === '') return false;
+        if ($color === '') {
+            return false;
+        }
 
         $lower = strtolower($color);
-        if (isset($colors[$lower])) return $colors[$lower];
+        if (isset($colors[$lower])) {
+            return $colors[$lower];
+        }
 
         if (strpos($color, 'rgb(') !== false) {
             // rgb literal handling
             $length = strlen($color);
-            if (strpos($color, ')') !== $length - 1) return false;
+            if (strpos($color, ')') !== $length - 1) {
+                return false;
+            }
             $triad = substr($color, 4, $length - 4 - 1);
             $parts = explode(',', $triad);
-            if (count($parts) !== 3) return false;
+            if (count($parts) !== 3) {
+                return false;
+            }
             $type = false; // to ensure that they're all the same type
             $new_parts = array();
             foreach ($parts as $part) {
                 $part = trim($part);
-                if ($part === '') return false;
+                if ($part === '') {
+                    return false;
+                }
                 $length = strlen($part);
                 if ($part[$length - 1] === '%') {
                     // handle percents
@@ -37,9 +55,13 @@ class HTMLPurifier_AttrDef_CSS_Color extends HTMLPurifier_AttrDef
                     } elseif ($type !== 'percentage') {
                         return false;
                     }
-                    $num = (float) substr($part, 0, $length - 1);
-                    if ($num < 0) $num = 0;
-                    if ($num > 100) $num = 100;
+                    $num = (float)substr($part, 0, $length - 1);
+                    if ($num < 0) {
+                        $num = 0;
+                    }
+                    if ($num > 100) {
+                        $num = 100;
+                    }
                     $new_parts[] = "$num%";
                 } else {
                     // handle integers
@@ -48,10 +70,14 @@ class HTMLPurifier_AttrDef_CSS_Color extends HTMLPurifier_AttrDef
                     } elseif ($type !== 'integer') {
                         return false;
                     }
-                    $num = (int) $part;
-                    if ($num < 0) $num = 0;
-                    if ($num > 255) $num = 255;
-                    $new_parts[] = (string) $num;
+                    $num = (int)$part;
+                    if ($num < 0) {
+                        $num = 0;
+                    }
+                    if ($num > 255) {
+                        $num = 255;
+                    }
+                    $new_parts[] = (string)$num;
                 }
             }
             $new_triad = implode(',', $new_parts);
@@ -65,14 +91,15 @@ class HTMLPurifier_AttrDef_CSS_Color extends HTMLPurifier_AttrDef
                 $color = '#' . $color;
             }
             $length = strlen($hex);
-            if ($length !== 3 && $length !== 6) return false;
-            if (!ctype_xdigit($hex)) return false;
+            if ($length !== 3 && $length !== 6) {
+                return false;
+            }
+            if (!ctype_xdigit($hex)) {
+                return false;
+            }
         }
-
         return $color;
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/Composite.php b/library/HTMLPurifier/AttrDef/CSS/Composite.php
index de1289cba..9c1750554 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Composite.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Composite.php
@@ -13,26 +13,36 @@ class HTMLPurifier_AttrDef_CSS_Composite extends HTMLPurifier_AttrDef
 {
 
     /**
-     * List of HTMLPurifier_AttrDef objects that may process strings
+     * List of objects that may process strings.
+     * @type HTMLPurifier_AttrDef[]
      * @todo Make protected
      */
     public $defs;
 
     /**
-     * @param $defs List of HTMLPurifier_AttrDef objects
+     * @param HTMLPurifier_AttrDef[] $defs List of HTMLPurifier_AttrDef objects
      */
-    public function __construct($defs) {
+    public function __construct($defs)
+    {
         $this->defs = $defs;
     }
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         foreach ($this->defs as $i => $def) {
             $result = $this->defs[$i]->validate($string, $config, $context);
-            if ($result !== false) return $result;
+            if ($result !== false) {
+                return $result;
+            }
         }
         return false;
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/DenyElementDecorator.php b/library/HTMLPurifier/AttrDef/CSS/DenyElementDecorator.php
index 6599c5b2d..9d77cc9aa 100644
--- a/library/HTMLPurifier/AttrDef/CSS/DenyElementDecorator.php
+++ b/library/HTMLPurifier/AttrDef/CSS/DenyElementDecorator.php
@@ -5,22 +5,38 @@
  */
 class HTMLPurifier_AttrDef_CSS_DenyElementDecorator extends HTMLPurifier_AttrDef
 {
-    public $def, $element;
+    /**
+     * @type HTMLPurifier_AttrDef
+     */
+    public $def;
+    /**
+     * @type string
+     */
+    public $element;
 
     /**
-     * @param $def Definition to wrap
-     * @param $element Element to deny
+     * @param HTMLPurifier_AttrDef $def Definition to wrap
+     * @param string $element Element to deny
      */
-    public function __construct($def, $element) {
+    public function __construct($def, $element)
+    {
         $this->def = $def;
         $this->element = $element;
     }
+
     /**
      * Checks if CurrentToken is set and equal to $this->element
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
      */
-    public function validate($string, $config, $context) {
+    public function validate($string, $config, $context)
+    {
         $token = $context->get('CurrentToken', true);
-        if ($token && $token->name == $this->element) return false;
+        if ($token && $token->name == $this->element) {
+            return false;
+        }
         return $this->def->validate($string, $config, $context);
     }
 }
diff --git a/library/HTMLPurifier/AttrDef/CSS/Filter.php b/library/HTMLPurifier/AttrDef/CSS/Filter.php
index 147894b86..bde4c3301 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Filter.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Filter.php
@@ -7,23 +7,37 @@
  */
 class HTMLPurifier_AttrDef_CSS_Filter extends HTMLPurifier_AttrDef
 {
-
+    /**
+     * @type HTMLPurifier_AttrDef_Integer
+     */
     protected $intValidator;
 
-    public function __construct() {
+    public function __construct()
+    {
         $this->intValidator = new HTMLPurifier_AttrDef_Integer();
     }
 
-    public function validate($value, $config, $context) {
+    /**
+     * @param string $value
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($value, $config, $context)
+    {
         $value = $this->parseCDATA($value);
-        if ($value === 'none') return $value;
+        if ($value === 'none') {
+            return $value;
+        }
         // if we looped this we could support multiple filters
         $function_length = strcspn($value, '(');
         $function = trim(substr($value, 0, $function_length));
         if ($function !== 'alpha' &&
             $function !== 'Alpha' &&
             $function !== 'progid:DXImageTransform.Microsoft.Alpha'
-            ) return false;
+        ) {
+            return false;
+        }
         $cursor = $function_length + 1;
         $parameters_length = strcspn($value, ')', $cursor);
         $parameters = substr($value, $cursor, $parameters_length);
@@ -32,15 +46,25 @@ class HTMLPurifier_AttrDef_CSS_Filter extends HTMLPurifier_AttrDef
         $lookup = array();
         foreach ($params as $param) {
             list($key, $value) = explode('=', $param);
-            $key   = trim($key);
+            $key = trim($key);
             $value = trim($value);
-            if (isset($lookup[$key])) continue;
-            if ($key !== 'opacity') continue;
+            if (isset($lookup[$key])) {
+                continue;
+            }
+            if ($key !== 'opacity') {
+                continue;
+            }
             $value = $this->intValidator->validate($value, $config, $context);
-            if ($value === false) continue;
-            $int = (int) $value;
-            if ($int > 100) $value = '100';
-            if ($int < 0) $value = '0';
+            if ($value === false) {
+                continue;
+            }
+            $int = (int)$value;
+            if ($int > 100) {
+                $value = '100';
+            }
+            if ($int < 0) {
+                $value = '0';
+            }
             $ret_params[] = "$key=$value";
             $lookup[$key] = true;
         }
@@ -48,7 +72,6 @@ class HTMLPurifier_AttrDef_CSS_Filter extends HTMLPurifier_AttrDef
         $ret_function = "$function($ret_parameters)";
         return $ret_function;
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/Font.php b/library/HTMLPurifier/AttrDef/CSS/Font.php
index 699ee0b70..579b97ef1 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Font.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Font.php
@@ -7,8 +7,8 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
 {
 
     /**
-     * Local copy of component validators.
-     *
+     * Local copy of validators
+     * @type HTMLPurifier_AttrDef[]
      * @note If we moved specific CSS property definitions to their own
      *       classes instead of having them be assembled at run time by
      *       CSSDefinition, this wouldn't be necessary.  We'd instantiate
@@ -16,18 +16,28 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
      */
     protected $info = array();
 
-    public function __construct($config) {
+    /**
+     * @param HTMLPurifier_Config $config
+     */
+    public function __construct($config)
+    {
         $def = $config->getCSSDefinition();
-        $this->info['font-style']   = $def->info['font-style'];
+        $this->info['font-style'] = $def->info['font-style'];
         $this->info['font-variant'] = $def->info['font-variant'];
-        $this->info['font-weight']  = $def->info['font-weight'];
-        $this->info['font-size']    = $def->info['font-size'];
-        $this->info['line-height']  = $def->info['line-height'];
-        $this->info['font-family']  = $def->info['font-family'];
+        $this->info['font-weight'] = $def->info['font-weight'];
+        $this->info['font-size'] = $def->info['font-size'];
+        $this->info['line-height'] = $def->info['line-height'];
+        $this->info['font-family'] = $def->info['font-family'];
     }
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         static $system_fonts = array(
             'caption' => true,
             'icon' => true,
@@ -39,7 +49,9 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
 
         // regular pre-processing
         $string = $this->parseCDATA($string);
-        if ($string === '') return false;
+        if ($string === '') {
+            return false;
+        }
 
         // check if it's one of the keywords
         $lowercase_string = strtolower($string);
@@ -54,15 +66,20 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
         $final = ''; // output
 
         for ($i = 0, $size = count($bits); $i < $size; $i++) {
-            if ($bits[$i] === '') continue;
+            if ($bits[$i] === '') {
+                continue;
+            }
             switch ($stage) {
-
-                // attempting to catch font-style, font-variant or font-weight
-                case 0:
+                case 0: // attempting to catch font-style, font-variant or font-weight
                     foreach ($stage_1 as $validator_name) {
-                        if (isset($caught[$validator_name])) continue;
+                        if (isset($caught[$validator_name])) {
+                            continue;
+                        }
                         $r = $this->info[$validator_name]->validate(
-                                                $bits[$i], $config, $context);
+                            $bits[$i],
+                            $config,
+                            $context
+                        );
                         if ($r !== false) {
                             $final .= $r . ' ';
                             $caught[$validator_name] = true;
@@ -70,15 +87,17 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
                         }
                     }
                     // all three caught, continue on
-                    if (count($caught) >= 3) $stage = 1;
-                    if ($r !== false) break;
-
-                // attempting to catch font-size and perhaps line-height
-                case 1:
+                    if (count($caught) >= 3) {
+                        $stage = 1;
+                    }
+                    if ($r !== false) {
+                        break;
+                    }
+                case 1: // attempting to catch font-size and perhaps line-height
                     $found_slash = false;
                     if (strpos($bits[$i], '/') !== false) {
                         list($font_size, $line_height) =
-                                                    explode('/', $bits[$i]);
+                            explode('/', $bits[$i]);
                         if ($line_height === '') {
                             // ooh, there's a space after the slash!
                             $line_height = false;
@@ -89,14 +108,19 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
                         $line_height = false;
                     }
                     $r = $this->info['font-size']->validate(
-                                              $font_size, $config, $context);
+                        $font_size,
+                        $config,
+                        $context
+                    );
                     if ($r !== false) {
                         $final .= $r;
                         // attempt to catch line-height
                         if ($line_height === false) {
                             // we need to scroll forward
                             for ($j = $i + 1; $j < $size; $j++) {
-                                if ($bits[$j] === '') continue;
+                                if ($bits[$j] === '') {
+                                    continue;
+                                }
                                 if ($bits[$j] === '/') {
                                     if ($found_slash) {
                                         return false;
@@ -116,7 +140,10 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
                         if ($found_slash) {
                             $i = $j;
                             $r = $this->info['line-height']->validate(
-                                              $line_height, $config, $context);
+                                $line_height,
+                                $config,
+                                $context
+                            );
                             if ($r !== false) {
                                 $final .= '/' . $r;
                             }
@@ -126,13 +153,14 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
                         break;
                     }
                     return false;
-
-                // attempting to catch font-family
-                case 2:
+                case 2: // attempting to catch font-family
                     $font_family =
                         implode(' ', array_slice($bits, $i, $size - $i));
                     $r = $this->info['font-family']->validate(
-                                              $font_family, $config, $context);
+                        $font_family,
+                        $config,
+                        $context
+                    );
                     if ($r !== false) {
                         $final .= $r . ' ';
                         // processing completed successfully
@@ -143,7 +171,6 @@ class HTMLPurifier_AttrDef_CSS_Font extends HTMLPurifier_AttrDef
         }
         return false;
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/FontFamily.php b/library/HTMLPurifier/AttrDef/CSS/FontFamily.php
index 42c2054c2..74e24c881 100644
--- a/library/HTMLPurifier/AttrDef/CSS/FontFamily.php
+++ b/library/HTMLPurifier/AttrDef/CSS/FontFamily.php
@@ -2,12 +2,58 @@
 
 /**
  * Validates a font family list according to CSS spec
- * @todo whitelisting allowed fonts would be nice
  */
 class HTMLPurifier_AttrDef_CSS_FontFamily extends HTMLPurifier_AttrDef
 {
 
-    public function validate($string, $config, $context) {
+    protected $mask = null;
+
+    public function __construct()
+    {
+        $this->mask = '_- ';
+        for ($c = 'a'; $c <= 'z'; $c++) {
+            $this->mask .= $c;
+        }
+        for ($c = 'A'; $c <= 'Z'; $c++) {
+            $this->mask .= $c;
+        }
+        for ($c = '0'; $c <= '9'; $c++) {
+            $this->mask .= $c;
+        } // cast-y, but should be fine
+        // special bytes used by UTF-8
+        for ($i = 0x80; $i <= 0xFF; $i++) {
+            // We don't bother excluding invalid bytes in this range,
+            // because the our restriction of well-formed UTF-8 will
+            // prevent these from ever occurring.
+            $this->mask .= chr($i);
+        }
+
+        /*
+            PHP's internal strcspn implementation is
+            O(length of string * length of mask), making it inefficient
+            for large masks.  However, it's still faster than
+            preg_match 8)
+          for (p = s1;;) {
+            spanp = s2;
+            do {
+              if (*spanp == c || p == s1_end) {
+                return p - s1;
+              }
+            } while (spanp++ < (s2_end - 1));
+            c = *++p;
+          }
+         */
+        // possible optimization: invert the mask.
+    }
+
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         static $generic_names = array(
             'serif' => true,
             'sans-serif' => true,
@@ -15,24 +61,33 @@ class HTMLPurifier_AttrDef_CSS_FontFamily extends HTMLPurifier_AttrDef
             'fantasy' => true,
             'cursive' => true
         );
+        $allowed_fonts = $config->get('CSS.AllowedFonts');
 
         // assume that no font names contain commas in them
         $fonts = explode(',', $string);
         $final = '';
-        foreach($fonts as $font) {
+        foreach ($fonts as $font) {
             $font = trim($font);
-            if ($font === '') continue;
+            if ($font === '') {
+                continue;
+            }
             // match a generic name
             if (isset($generic_names[$font])) {
-                $final .= $font . ', ';
+                if ($allowed_fonts === null || isset($allowed_fonts[$font])) {
+                    $final .= $font . ', ';
+                }
                 continue;
             }
             // match a quoted name
             if ($font[0] === '"' || $font[0] === "'") {
                 $length = strlen($font);
-                if ($length <= 2) continue;
+                if ($length <= 2) {
+                    continue;
+                }
                 $quote = $font[0];
-                if ($font[$length - 1] !== $quote) continue;
+                if ($font[$length - 1] !== $quote) {
+                    continue;
+                }
                 $font = substr($font, 1, $length - 2);
             }
 
@@ -40,6 +95,10 @@ class HTMLPurifier_AttrDef_CSS_FontFamily extends HTMLPurifier_AttrDef
 
             // $font is a pure representation of the font name
 
+            if ($allowed_fonts !== null && !isset($allowed_fonts[$font])) {
+                continue;
+            }
+
             if (ctype_alnum($font) && $font !== '') {
                 // very simple font, allow it in unharmed
                 $final .= $font . ', ';
@@ -50,20 +109,108 @@ class HTMLPurifier_AttrDef_CSS_FontFamily extends HTMLPurifier_AttrDef
             // shouldn't show up regardless
             $font = str_replace(array("\n", "\t", "\r", "\x0C"), ' ', $font);
 
-            // These ugly transforms don't pose a security
-            // risk (as \\ and \" might).  We could try to be clever and
-            // use single-quote wrapping when there is a double quote
-            // present, but I have choosen not to implement that.
-            // (warning: this code relies on the selection of quotation
-            // mark below)
-            $font = str_replace('\\', '\\5C ', $font);
-            $font = str_replace('"',  '\\22 ', $font);
-
-            // complicated font, requires quoting
-            $final .= "\"$font\", "; // note that this will later get turned into &quot;
+            // Here, there are various classes of characters which need
+            // to be treated differently:
+            //  - Alphanumeric characters are essentially safe.  We
+            //    handled these above.
+            //  - Spaces require quoting, though most parsers will do
+            //    the right thing if there aren't any characters that
+            //    can be misinterpreted
+            //  - Dashes rarely occur, but they fairly unproblematic
+            //    for parsing/rendering purposes.
+            //  The above characters cover the majority of Western font
+            //  names.
+            //  - Arbitrary Unicode characters not in ASCII.  Because
+            //    most parsers give little thought to Unicode, treatment
+            //    of these codepoints is basically uniform, even for
+            //    punctuation-like codepoints.  These characters can
+            //    show up in non-Western pages and are supported by most
+            //    major browsers, for example: "ＭＳ 明朝" is a
+            //    legitimate font-name
+            //    <http://ja.wikipedia.org/wiki/MS_明朝>.  See
+            //    the CSS3 spec for more examples:
+            //    <http://www.w3.org/TR/2011/WD-css3-fonts-20110324/localizedfamilynames.png>
+            //    You can see live samples of these on the Internet:
+            //    <http://www.google.co.jp/search?q=font-family+ＭＳ+明朝|ゴシック>
+            //    However, most of these fonts have ASCII equivalents:
+            //    for example, 'MS Mincho', and it's considered
+            //    professional to use ASCII font names instead of
+            //    Unicode font names.  Thanks Takeshi Terada for
+            //    providing this information.
+            //  The following characters, to my knowledge, have not been
+            //  used to name font names.
+            //  - Single quote.  While theoretically you might find a
+            //    font name that has a single quote in its name (serving
+            //    as an apostrophe, e.g. Dave's Scribble), I haven't
+            //    been able to find any actual examples of this.
+            //    Internet Explorer's cssText translation (which I
+            //    believe is invoked by innerHTML) normalizes any
+            //    quoting to single quotes, and fails to escape single
+            //    quotes.  (Note that this is not IE's behavior for all
+            //    CSS properties, just some sort of special casing for
+            //    font-family).  So a single quote *cannot* be used
+            //    safely in the font-family context if there will be an
+            //    innerHTML/cssText translation.  Note that Firefox 3.x
+            //    does this too.
+            //  - Double quote.  In IE, these get normalized to
+            //    single-quotes, no matter what the encoding.  (Fun
+            //    fact, in IE8, the 'content' CSS property gained
+            //    support, where they special cased to preserve encoded
+            //    double quotes, but still translate unadorned double
+            //    quotes into single quotes.)  So, because their
+            //    fixpoint behavior is identical to single quotes, they
+            //    cannot be allowed either.  Firefox 3.x displays
+            //    single-quote style behavior.
+            //  - Backslashes are reduced by one (so \\ -> \) every
+            //    iteration, so they cannot be used safely.  This shows
+            //    up in IE7, IE8 and FF3
+            //  - Semicolons, commas and backticks are handled properly.
+            //  - The rest of the ASCII punctuation is handled properly.
+            // We haven't checked what browsers do to unadorned
+            // versions, but this is not important as long as the
+            // browser doesn't /remove/ surrounding quotes (as IE does
+            // for HTML).
+            //
+            // With these results in hand, we conclude that there are
+            // various levels of safety:
+            //  - Paranoid: alphanumeric, spaces and dashes(?)
+            //  - International: Paranoid + non-ASCII Unicode
+            //  - Edgy: Everything except quotes, backslashes
+            //  - NoJS: Standards compliance, e.g. sod IE. Note that
+            //    with some judicious character escaping (since certain
+            //    types of escaping doesn't work) this is theoretically
+            //    OK as long as innerHTML/cssText is not called.
+            // We believe that international is a reasonable default
+            // (that we will implement now), and once we do more
+            // extensive research, we may feel comfortable with dropping
+            // it down to edgy.
+
+            // Edgy: alphanumeric, spaces, dashes, underscores and Unicode.  Use of
+            // str(c)spn assumes that the string was already well formed
+            // Unicode (which of course it is).
+            if (strspn($font, $this->mask) !== strlen($font)) {
+                continue;
+            }
+
+            // Historical:
+            // In the absence of innerHTML/cssText, these ugly
+            // transforms don't pose a security risk (as \\ and \"
+            // might--these escapes are not supported by most browsers).
+            // We could try to be clever and use single-quote wrapping
+            // when there is a double quote present, but I have choosen
+            // not to implement that.  (NOTE: you can reduce the amount
+            // of escapes by one depending on what quoting style you use)
+            // $font = str_replace('\\', '\\5C ', $font);
+            // $font = str_replace('"',  '\\22 ', $font);
+            // $font = str_replace("'",  '\\27 ', $font);
+
+            // font possibly with spaces, requires quoting
+            $final .= "'$font', ";
         }
         $final = rtrim($final, ', ');
-        if ($final === '') return false;
+        if ($final === '') {
+            return false;
+        }
         return $final;
     }
 
diff --git a/library/HTMLPurifier/AttrDef/CSS/Ident.php b/library/HTMLPurifier/AttrDef/CSS/Ident.php
new file mode 100644
index 000000000..973002c17
--- /dev/null
+++ b/library/HTMLPurifier/AttrDef/CSS/Ident.php
@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Validates based on {ident} CSS grammar production
+ */
+class HTMLPurifier_AttrDef_CSS_Ident extends HTMLPurifier_AttrDef
+{
+
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
+        $string = trim($string);
+
+        // early abort: '' and '0' (strings that convert to false) are invalid
+        if (!$string) {
+            return false;
+        }
+
+        $pattern = '/^(-?[A-Za-z_][A-Za-z_\-0-9]*)$/';
+        if (!preg_match($pattern, $string)) {
+            return false;
+        }
+        return $string;
+    }
+}
+
+// vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/ImportantDecorator.php b/library/HTMLPurifier/AttrDef/CSS/ImportantDecorator.php
index 4e6b35e5a..ffc989fe8 100644
--- a/library/HTMLPurifier/AttrDef/CSS/ImportantDecorator.php
+++ b/library/HTMLPurifier/AttrDef/CSS/ImportantDecorator.php
@@ -5,20 +5,34 @@
  */
 class HTMLPurifier_AttrDef_CSS_ImportantDecorator extends HTMLPurifier_AttrDef
 {
-    public $def, $allow;
+    /**
+     * @type HTMLPurifier_AttrDef
+     */
+    public $def;
+    /**
+     * @type bool
+     */
+    public $allow;
 
     /**
-     * @param $def Definition to wrap
-     * @param $allow Whether or not to allow !important
+     * @param HTMLPurifier_AttrDef $def Definition to wrap
+     * @param bool $allow Whether or not to allow !important
      */
-    public function __construct($def, $allow = false) {
+    public function __construct($def, $allow = false)
+    {
         $this->def = $def;
         $this->allow = $allow;
     }
+
     /**
      * Intercepts and removes !important if necessary
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
      */
-    public function validate($string, $config, $context) {
+    public function validate($string, $config, $context)
+    {
         // test for ! and important tokens
         $string = trim($string);
         $is_important = false;
@@ -32,7 +46,9 @@ class HTMLPurifier_AttrDef_CSS_ImportantDecorator extends HTMLPurifier_AttrDef
             }
         }
         $string = $this->def->validate($string, $config, $context);
-        if ($this->allow && $is_important) $string .= ' !important';
+        if ($this->allow && $is_important) {
+            $string .= ' !important';
+        }
         return $string;
     }
 }
diff --git a/library/HTMLPurifier/AttrDef/CSS/Length.php b/library/HTMLPurifier/AttrDef/CSS/Length.php
index a07ec5813..f12453a04 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Length.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Length.php
@@ -6,42 +6,72 @@
 class HTMLPurifier_AttrDef_CSS_Length extends HTMLPurifier_AttrDef
 {
 
-    protected $min, $max;
+    /**
+     * @type HTMLPurifier_Length|string
+     */
+    protected $min;
 
     /**
-     * @param HTMLPurifier_Length $max Minimum length, or null for no bound. String is also acceptable.
-     * @param HTMLPurifier_Length $max Maximum length, or null for no bound. String is also acceptable.
+     * @type HTMLPurifier_Length|string
      */
-    public function __construct($min = null, $max = null) {
+    protected $max;
+
+    /**
+     * @param HTMLPurifier_Length|string $min Minimum length, or null for no bound. String is also acceptable.
+     * @param HTMLPurifier_Length|string $max Maximum length, or null for no bound. String is also acceptable.
+     */
+    public function __construct($min = null, $max = null)
+    {
         $this->min = $min !== null ? HTMLPurifier_Length::make($min) : null;
         $this->max = $max !== null ? HTMLPurifier_Length::make($max) : null;
     }
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = $this->parseCDATA($string);
 
         // Optimizations
-        if ($string === '') return false;
-        if ($string === '0') return '0';
-        if (strlen($string) === 1) return false;
+        if ($string === '') {
+            return false;
+        }
+        if ($string === '0') {
+            return '0';
+        }
+        if (strlen($string) === 1) {
+            return false;
+        }
 
         $length = HTMLPurifier_Length::make($string);
-        if (!$length->isValid()) return false;
+        if (!$length->isValid()) {
+            return false;
+        }
 
         if ($this->min) {
             $c = $length->compareTo($this->min);
-            if ($c === false) return false;
-            if ($c < 0) return false;
+            if ($c === false) {
+                return false;
+            }
+            if ($c < 0) {
+                return false;
+            }
         }
         if ($this->max) {
             $c = $length->compareTo($this->max);
-            if ($c === false) return false;
-            if ($c > 0) return false;
+            if ($c === false) {
+                return false;
+            }
+            if ($c > 0) {
+                return false;
+            }
         }
-
         return $length->toString();
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/ListStyle.php b/library/HTMLPurifier/AttrDef/CSS/ListStyle.php
index 4406868c0..e74d42654 100644
--- a/library/HTMLPurifier/AttrDef/CSS/ListStyle.php
+++ b/library/HTMLPurifier/AttrDef/CSS/ListStyle.php
@@ -8,46 +8,72 @@ class HTMLPurifier_AttrDef_CSS_ListStyle extends HTMLPurifier_AttrDef
 {
 
     /**
-     * Local copy of component validators.
+     * Local copy of validators.
+     * @type HTMLPurifier_AttrDef[]
      * @note See HTMLPurifier_AttrDef_CSS_Font::$info for a similar impl.
      */
     protected $info;
 
-    public function __construct($config) {
+    /**
+     * @param HTMLPurifier_Config $config
+     */
+    public function __construct($config)
+    {
         $def = $config->getCSSDefinition();
-        $this->info['list-style-type']     = $def->info['list-style-type'];
+        $this->info['list-style-type'] = $def->info['list-style-type'];
         $this->info['list-style-position'] = $def->info['list-style-position'];
         $this->info['list-style-image'] = $def->info['list-style-image'];
     }
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         // regular pre-processing
         $string = $this->parseCDATA($string);
-        if ($string === '') return false;
+        if ($string === '') {
+            return false;
+        }
 
         // assumes URI doesn't have spaces in it
         $bits = explode(' ', strtolower($string)); // bits to process
 
         $caught = array();
-        $caught['type']     = false;
+        $caught['type'] = false;
         $caught['position'] = false;
-        $caught['image']    = false;
+        $caught['image'] = false;
 
         $i = 0; // number of catches
         $none = false;
 
         foreach ($bits as $bit) {
-            if ($i >= 3) return; // optimization bit
-            if ($bit === '') continue;
+            if ($i >= 3) {
+                return;
+            } // optimization bit
+            if ($bit === '') {
+                continue;
+            }
             foreach ($caught as $key => $status) {
-                if ($status !== false) continue;
+                if ($status !== false) {
+                    continue;
+                }
                 $r = $this->info['list-style-' . $key]->validate($bit, $config, $context);
-                if ($r === false) continue;
+                if ($r === false) {
+                    continue;
+                }
                 if ($r === 'none') {
-                    if ($none) continue;
-                    else $none = true;
-                    if ($key == 'image') continue;
+                    if ($none) {
+                        continue;
+                    } else {
+                        $none = true;
+                    }
+                    if ($key == 'image') {
+                        continue;
+                    }
                 }
                 $caught[$key] = $r;
                 $i++;
@@ -55,24 +81,32 @@ class HTMLPurifier_AttrDef_CSS_ListStyle extends HTMLPurifier_AttrDef
             }
         }
 
-        if (!$i) return false;
+        if (!$i) {
+            return false;
+        }
 
         $ret = array();
 
         // construct type
-        if ($caught['type']) $ret[] = $caught['type'];
+        if ($caught['type']) {
+            $ret[] = $caught['type'];
+        }
 
         // construct image
-        if ($caught['image']) $ret[] = $caught['image'];
+        if ($caught['image']) {
+            $ret[] = $caught['image'];
+        }
 
         // construct position
-        if ($caught['position']) $ret[] = $caught['position'];
+        if ($caught['position']) {
+            $ret[] = $caught['position'];
+        }
 
-        if (empty($ret)) return false;
+        if (empty($ret)) {
+            return false;
+        }
         return implode(' ', $ret);
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/Multiple.php b/library/HTMLPurifier/AttrDef/CSS/Multiple.php
index 4d62a40d7..9f266cdd1 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Multiple.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Multiple.php
@@ -13,9 +13,9 @@
  */
 class HTMLPurifier_AttrDef_CSS_Multiple extends HTMLPurifier_AttrDef
 {
-
     /**
      * Instance of component definition to defer validation to.
+     * @type HTMLPurifier_AttrDef
      * @todo Make protected
      */
     public $single;
@@ -27,32 +27,45 @@ class HTMLPurifier_AttrDef_CSS_Multiple extends HTMLPurifier_AttrDef
     public $max;
 
     /**
-     * @param $single HTMLPurifier_AttrDef to multiply
-     * @param $max Max number of values allowed (usually four)
+     * @param HTMLPurifier_AttrDef $single HTMLPurifier_AttrDef to multiply
+     * @param int $max Max number of values allowed (usually four)
      */
-    public function __construct($single, $max = 4) {
+    public function __construct($single, $max = 4)
+    {
         $this->single = $single;
         $this->max = $max;
     }
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = $this->parseCDATA($string);
-        if ($string === '') return false;
+        if ($string === '') {
+            return false;
+        }
         $parts = explode(' ', $string); // parseCDATA replaced \r, \t and \n
         $length = count($parts);
         $final = '';
         for ($i = 0, $num = 0; $i < $length && $num < $this->max; $i++) {
-            if (ctype_space($parts[$i])) continue;
+            if (ctype_space($parts[$i])) {
+                continue;
+            }
             $result = $this->single->validate($parts[$i], $config, $context);
             if ($result !== false) {
                 $final .= $result . ' ';
                 $num++;
             }
         }
-        if ($final === '') return false;
+        if ($final === '') {
+            return false;
+        }
         return rtrim($final);
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/Number.php b/library/HTMLPurifier/AttrDef/CSS/Number.php
index 3f99e12ec..8edc159e7 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Number.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Number.php
@@ -7,32 +7,44 @@ class HTMLPurifier_AttrDef_CSS_Number extends HTMLPurifier_AttrDef
 {
 
     /**
-     * Bool indicating whether or not only positive values allowed.
+     * Indicates whether or not only positive values are allowed.
+     * @type bool
      */
     protected $non_negative = false;
 
     /**
-     * @param $non_negative Bool indicating whether negatives are forbidden
+     * @param bool $non_negative indicates whether negatives are forbidden
      */
-    public function __construct($non_negative = false) {
+    public function __construct($non_negative = false)
+    {
         $this->non_negative = $non_negative;
     }
 
     /**
+     * @param string $number
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return string|bool
      * @warning Some contexts do not pass $config, $context. These
      *          variables should not be used without checking HTMLPurifier_Length
      */
-    public function validate($number, $config, $context) {
-
+    public function validate($number, $config, $context)
+    {
         $number = $this->parseCDATA($number);
 
-        if ($number === '') return false;
-        if ($number === '0') return '0';
+        if ($number === '') {
+            return false;
+        }
+        if ($number === '0') {
+            return '0';
+        }
 
         $sign = '';
         switch ($number[0]) {
             case '-':
-                if ($this->non_negative) return false;
+                if ($this->non_negative) {
+                    return false;
+                }
                 $sign = '-';
             case '+':
                 $number = substr($number, 1);
@@ -44,14 +56,20 @@ class HTMLPurifier_AttrDef_CSS_Number extends HTMLPurifier_AttrDef
         }
 
         // Period is the only non-numeric character allowed
-        if (strpos($number, '.') === false) return false;
+        if (strpos($number, '.') === false) {
+            return false;
+        }
 
         list($left, $right) = explode('.', $number, 2);
 
-        if ($left === '' && $right === '') return false;
-        if ($left !== '' && !ctype_digit($left)) return false;
+        if ($left === '' && $right === '') {
+            return false;
+        }
+        if ($left !== '' && !ctype_digit($left)) {
+            return false;
+        }
 
-        $left  = ltrim($left,  '0');
+        $left = ltrim($left, '0');
         $right = rtrim($right, '0');
 
         if ($right === '') {
@@ -59,11 +77,8 @@ class HTMLPurifier_AttrDef_CSS_Number extends HTMLPurifier_AttrDef
         } elseif (!ctype_digit($right)) {
             return false;
         }
-
         return $sign . $left . '.' . $right;
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/Percentage.php b/library/HTMLPurifier/AttrDef/CSS/Percentage.php
index c34b8fc3c..f0f25c50a 100644
--- a/library/HTMLPurifier/AttrDef/CSS/Percentage.php
+++ b/library/HTMLPurifier/AttrDef/CSS/Percentage.php
@@ -7,34 +7,48 @@ class HTMLPurifier_AttrDef_CSS_Percentage extends HTMLPurifier_AttrDef
 {
 
     /**
-     * Instance of HTMLPurifier_AttrDef_CSS_Number to defer number validation
+     * Instance to defer number validation to.
+     * @type HTMLPurifier_AttrDef_CSS_Number
      */
     protected $number_def;
 
     /**
-     * @param Bool indicating whether to forbid negative values
+     * @param bool $non_negative Whether to forbid negative values
      */
-    public function __construct($non_negative = false) {
+    public function __construct($non_negative = false)
+    {
         $this->number_def = new HTMLPurifier_AttrDef_CSS_Number($non_negative);
     }
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = $this->parseCDATA($string);
 
-        if ($string === '') return false;
+        if ($string === '') {
+            return false;
+        }
         $length = strlen($string);
-        if ($length === 1) return false;
-        if ($string[$length - 1] !== '%') return false;
+        if ($length === 1) {
+            return false;
+        }
+        if ($string[$length - 1] !== '%') {
+            return false;
+        }
 
         $number = substr($string, 0, $length - 1);
         $number = $this->number_def->validate($number, $config, $context);
 
-        if ($number === false) return false;
+        if ($number === false) {
+            return false;
+        }
         return "$number%";
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/TextDecoration.php b/library/HTMLPurifier/AttrDef/CSS/TextDecoration.php
index 772c922d8..5fd4b7f7b 100644
--- a/library/HTMLPurifier/AttrDef/CSS/TextDecoration.php
+++ b/library/HTMLPurifier/AttrDef/CSS/TextDecoration.php
@@ -8,8 +8,14 @@
 class HTMLPurifier_AttrDef_CSS_TextDecoration extends HTMLPurifier_AttrDef
 {
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         static $allowed_values = array(
             'line-through' => true,
             'overline' => true,
@@ -18,7 +24,9 @@ class HTMLPurifier_AttrDef_CSS_TextDecoration extends HTMLPurifier_AttrDef
 
         $string = strtolower($this->parseCDATA($string));
 
-        if ($string === 'none') return $string;
+        if ($string === 'none') {
+            return $string;
+        }
 
         $parts = explode(' ', $string);
         $final = '';
@@ -28,11 +36,11 @@ class HTMLPurifier_AttrDef_CSS_TextDecoration extends HTMLPurifier_AttrDef
             }
         }
         $final = rtrim($final);
-        if ($final === '') return false;
+        if ($final === '') {
+            return false;
+        }
         return $final;
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/CSS/URI.php b/library/HTMLPurifier/AttrDef/CSS/URI.php
index 1df17dc25..f9434230e 100644
--- a/library/HTMLPurifier/AttrDef/CSS/URI.php
+++ b/library/HTMLPurifier/AttrDef/CSS/URI.php
@@ -12,25 +12,39 @@
 class HTMLPurifier_AttrDef_CSS_URI extends HTMLPurifier_AttrDef_URI
 {
 
-    public function __construct() {
+    public function __construct()
+    {
         parent::__construct(true); // always embedded
     }
 
-    public function validate($uri_string, $config, $context) {
+    /**
+     * @param string $uri_string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($uri_string, $config, $context)
+    {
         // parse the URI out of the string and then pass it onto
         // the parent object
 
         $uri_string = $this->parseCDATA($uri_string);
-        if (strpos($uri_string, 'url(') !== 0) return false;
+        if (strpos($uri_string, 'url(') !== 0) {
+            return false;
+        }
         $uri_string = substr($uri_string, 4);
         $new_length = strlen($uri_string) - 1;
-        if ($uri_string[$new_length] != ')') return false;
+        if ($uri_string[$new_length] != ')') {
+            return false;
+        }
         $uri = trim(substr($uri_string, 0, $new_length));
 
         if (!empty($uri) && ($uri[0] == "'" || $uri[0] == '"')) {
             $quote = $uri[0];
             $new_length = strlen($uri) - 1;
-            if ($uri[$new_length] !== $quote) return false;
+            if ($uri[$new_length] !== $quote) {
+                return false;
+            }
             $uri = substr($uri, 1, $new_length - 1);
         }
 
@@ -38,15 +52,23 @@ class HTMLPurifier_AttrDef_CSS_URI extends HTMLPurifier_AttrDef_URI
 
         $result = parent::validate($uri, $config, $context);
 
-        if ($result === false) return false;
+        if ($result === false) {
+            return false;
+        }
 
         // extra sanity check; should have been done by URI
         $result = str_replace(array('"', "\\", "\n", "\x0c", "\r"), "", $result);
 
-        return "url(\"$result\")";
+        // suspicious characters are ()'; we're going to percent encode
+        // them for safety.
+        $result = str_replace(array('(', ')', "'"), array('%28', '%29', '%27'), $result);
 
+        // there's an extra bug where ampersands lose their escaping on
+        // an innerHTML cycle, so a very unlucky query parameter could
+        // then change the meaning of the URL.  Unfortunately, there's
+        // not much we can do about that...
+        return "url(\"$result\")";
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/Clone.php b/library/HTMLPurifier/AttrDef/Clone.php
new file mode 100644
index 000000000..6698a00c0
--- /dev/null
+++ b/library/HTMLPurifier/AttrDef/Clone.php
@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * Dummy AttrDef that mimics another AttrDef, BUT it generates clones
+ * with make.
+ */
+class HTMLPurifier_AttrDef_Clone extends HTMLPurifier_AttrDef
+{
+    /**
+     * What we're cloning.
+     * @type HTMLPurifier_AttrDef
+     */
+    protected $clone;
+
+    /**
+     * @param HTMLPurifier_AttrDef $clone
+     */
+    public function __construct($clone)
+    {
+        $this->clone = $clone;
+    }
+
+    /**
+     * @param string $v
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($v, $config, $context)
+    {
+        return $this->clone->validate($v, $config, $context);
+    }
+
+    /**
+     * @param string $string
+     * @return HTMLPurifier_AttrDef
+     */
+    public function make($string)
+    {
+        return clone $this->clone;
+    }
+}
+
+// vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/Enum.php b/library/HTMLPurifier/AttrDef/Enum.php
index 5d603ebcc..8abda7f6e 100644
--- a/library/HTMLPurifier/AttrDef/Enum.php
+++ b/library/HTMLPurifier/AttrDef/Enum.php
@@ -12,9 +12,10 @@ class HTMLPurifier_AttrDef_Enum extends HTMLPurifier_AttrDef
 
     /**
      * Lookup table of valid values.
+     * @type array
      * @todo Make protected
      */
-    public $valid_values   = array();
+    public $valid_values = array();
 
     /**
      * Bool indicating whether or not enumeration is case sensitive.
@@ -23,17 +24,23 @@ class HTMLPurifier_AttrDef_Enum extends HTMLPurifier_AttrDef
     protected $case_sensitive = false; // values according to W3C spec
 
     /**
-     * @param $valid_values List of valid values
-     * @param $case_sensitive Bool indicating whether or not case sensitive
+     * @param array $valid_values List of valid values
+     * @param bool $case_sensitive Whether or not case sensitive
      */
-    public function __construct(
-        $valid_values = array(), $case_sensitive = false
-    ) {
+    public function __construct($valid_values = array(), $case_sensitive = false)
+    {
         $this->valid_values = array_flip($valid_values);
         $this->case_sensitive = $case_sensitive;
     }
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = trim($string);
         if (!$this->case_sensitive) {
             // we may want to do full case-insensitive libraries
@@ -45,11 +52,13 @@ class HTMLPurifier_AttrDef_Enum extends HTMLPurifier_AttrDef
     }
 
     /**
-     * @param $string In form of comma-delimited list of case-insensitive
+     * @param string $string In form of comma-delimited list of case-insensitive
      *      valid values. Example: "foo,bar,baz". Prepend "s:" to make
      *      case sensitive
+     * @return HTMLPurifier_AttrDef_Enum
      */
-    public function make($string) {
+    public function make($string)
+    {
         if (strlen($string) > 2 && $string[0] == 's' && $string[1] == ':') {
             $string = substr($string, 2);
             $sensitive = true;
@@ -59,7 +68,6 @@ class HTMLPurifier_AttrDef_Enum extends HTMLPurifier_AttrDef
         $values = explode(',', $string);
         return new HTMLPurifier_AttrDef_Enum($values, $sensitive);
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/Bool.php b/library/HTMLPurifier/AttrDef/HTML/Bool.php
index e06987eb8..036a240e1 100644
--- a/library/HTMLPurifier/AttrDef/HTML/Bool.php
+++ b/library/HTMLPurifier/AttrDef/HTML/Bool.php
@@ -6,23 +6,46 @@
 class HTMLPurifier_AttrDef_HTML_Bool extends HTMLPurifier_AttrDef
 {
 
+    /**
+     * @type bool
+     */
     protected $name;
+
+    /**
+     * @type bool
+     */
     public $minimized = true;
 
-    public function __construct($name = false) {$this->name = $name;}
+    /**
+     * @param bool $name
+     */
+    public function __construct($name = false)
+    {
+        $this->name = $name;
+    }
 
-    public function validate($string, $config, $context) {
-        if (empty($string)) return false;
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
+        if (empty($string)) {
+            return false;
+        }
         return $this->name;
     }
 
     /**
-     * @param $string Name of attribute
+     * @param string $string Name of attribute
+     * @return HTMLPurifier_AttrDef_HTML_Bool
      */
-    public function make($string) {
+    public function make($string)
+    {
         return new HTMLPurifier_AttrDef_HTML_Bool($string);
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/Class.php b/library/HTMLPurifier/AttrDef/HTML/Class.php
index 370068d97..d5013488f 100644
--- a/library/HTMLPurifier/AttrDef/HTML/Class.php
+++ b/library/HTMLPurifier/AttrDef/HTML/Class.php
@@ -5,7 +5,14 @@
  */
 class HTMLPurifier_AttrDef_HTML_Class extends HTMLPurifier_AttrDef_HTML_Nmtokens
 {
-    protected function split($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    protected function split($string, $config, $context)
+    {
         // really, this twiddle should be lazy loaded
         $name = $config->getDefinition('HTML')->doctype->name;
         if ($name == "XHTML 1.1" || $name == "XHTML 2.0") {
@@ -14,13 +21,20 @@ class HTMLPurifier_AttrDef_HTML_Class extends HTMLPurifier_AttrDef_HTML_Nmtokens
             return preg_split('/\s+/', $string);
         }
     }
-    protected function filter($tokens, $config, $context) {
+
+    /**
+     * @param array $tokens
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return array
+     */
+    protected function filter($tokens, $config, $context)
+    {
         $allowed = $config->get('Attr.AllowedClasses');
         $forbidden = $config->get('Attr.ForbiddenClasses');
         $ret = array();
         foreach ($tokens as $token) {
-            if (
-                ($allowed === null || isset($allowed[$token])) &&
+            if (($allowed === null || isset($allowed[$token])) &&
                 !isset($forbidden[$token]) &&
                 // We need this O(n) check because of PHP's array
                 // implementation that casts -0 to 0.
diff --git a/library/HTMLPurifier/AttrDef/HTML/Color.php b/library/HTMLPurifier/AttrDef/HTML/Color.php
index d01e20454..946ebb782 100644
--- a/library/HTMLPurifier/AttrDef/HTML/Color.php
+++ b/library/HTMLPurifier/AttrDef/HTML/Color.php
@@ -6,27 +6,46 @@
 class HTMLPurifier_AttrDef_HTML_Color extends HTMLPurifier_AttrDef
 {
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         static $colors = null;
-        if ($colors === null) $colors = $config->get('Core.ColorKeywords');
+        if ($colors === null) {
+            $colors = $config->get('Core.ColorKeywords');
+        }
 
         $string = trim($string);
 
-        if (empty($string)) return false;
-        if (isset($colors[$string])) return $colors[$string];
-        if ($string[0] === '#') $hex = substr($string, 1);
-        else $hex = $string;
+        if (empty($string)) {
+            return false;
+        }
+        $lower = strtolower($string);
+        if (isset($colors[$lower])) {
+            return $colors[$lower];
+        }
+        if ($string[0] === '#') {
+            $hex = substr($string, 1);
+        } else {
+            $hex = $string;
+        }
 
         $length = strlen($hex);
-        if ($length !== 3 && $length !== 6) return false;
-        if (!ctype_xdigit($hex)) return false;
-        if ($length === 3) $hex = $hex[0].$hex[0].$hex[1].$hex[1].$hex[2].$hex[2];
-
+        if ($length !== 3 && $length !== 6) {
+            return false;
+        }
+        if (!ctype_xdigit($hex)) {
+            return false;
+        }
+        if ($length === 3) {
+            $hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
+        }
         return "#$hex";
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/FrameTarget.php b/library/HTMLPurifier/AttrDef/HTML/FrameTarget.php
index ae6ea7c01..d79ba12b3 100644
--- a/library/HTMLPurifier/AttrDef/HTML/FrameTarget.php
+++ b/library/HTMLPurifier/AttrDef/HTML/FrameTarget.php
@@ -6,16 +6,33 @@
 class HTMLPurifier_AttrDef_HTML_FrameTarget extends HTMLPurifier_AttrDef_Enum
 {
 
+    /**
+     * @type array
+     */
     public $valid_values = false; // uninitialized value
+
+    /**
+     * @type bool
+     */
     protected $case_sensitive = false;
 
-    public function __construct() {}
+    public function __construct()
+    {
+    }
 
-    public function validate($string, $config, $context) {
-        if ($this->valid_values === false) $this->valid_values = $config->get('Attr.AllowedFrameTargets');
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
+        if ($this->valid_values === false) {
+            $this->valid_values = $config->get('Attr.AllowedFrameTargets');
+        }
         return parent::validate($string, $config, $context);
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/ID.php b/library/HTMLPurifier/AttrDef/HTML/ID.php
index 81d03762d..3d86efb44 100644
--- a/library/HTMLPurifier/AttrDef/HTML/ID.php
+++ b/library/HTMLPurifier/AttrDef/HTML/ID.php
@@ -12,42 +12,77 @@
 class HTMLPurifier_AttrDef_HTML_ID extends HTMLPurifier_AttrDef
 {
 
-    // ref functionality disabled, since we also have to verify
-    // whether or not the ID it refers to exists
-
-    public function validate($id, $config, $context) {
+    // selector is NOT a valid thing to use for IDREFs, because IDREFs
+    // *must* target IDs that exist, whereas selector #ids do not.
+
+    /**
+     * Determines whether or not we're validating an ID in a CSS
+     * selector context.
+     * @type bool
+     */
+    protected $selector;
+
+    /**
+     * @param bool $selector
+     */
+    public function __construct($selector = false)
+    {
+        $this->selector = $selector;
+    }
 
-        if (!$config->get('Attr.EnableID')) return false;
+    /**
+     * @param string $id
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($id, $config, $context)
+    {
+        if (!$this->selector && !$config->get('Attr.EnableID')) {
+            return false;
+        }
 
         $id = trim($id); // trim it first
 
-        if ($id === '') return false;
+        if ($id === '') {
+            return false;
+        }
 
         $prefix = $config->get('Attr.IDPrefix');
         if ($prefix !== '') {
             $prefix .= $config->get('Attr.IDPrefixLocal');
             // prevent re-appending the prefix
-            if (strpos($id, $prefix) !== 0) $id = $prefix . $id;
+            if (strpos($id, $prefix) !== 0) {
+                $id = $prefix . $id;
+            }
         } elseif ($config->get('Attr.IDPrefixLocal') !== '') {
-            trigger_error('%Attr.IDPrefixLocal cannot be used unless '.
-                '%Attr.IDPrefix is set', E_USER_WARNING);
+            trigger_error(
+                '%Attr.IDPrefixLocal cannot be used unless ' .
+                '%Attr.IDPrefix is set',
+                E_USER_WARNING
+            );
         }
 
-        //if (!$this->ref) {
+        if (!$this->selector) {
             $id_accumulator =& $context->get('IDAccumulator');
-            if (isset($id_accumulator->ids[$id])) return false;
-        //}
+            if (isset($id_accumulator->ids[$id])) {
+                return false;
+            }
+        }
 
         // we purposely avoid using regex, hopefully this is faster
 
         if (ctype_alpha($id)) {
             $result = true;
         } else {
-            if (!ctype_alpha(@$id[0])) return false;
-            $trim = trim( // primitive style of regexps, I suppose
+            if (!ctype_alpha(@$id[0])) {
+                return false;
+            }
+            // primitive style of regexps, I suppose
+            $trim = trim(
                 $id,
                 'A..Za..z0..9:-._'
-              );
+            );
             $result = ($trim === '');
         }
 
@@ -56,15 +91,15 @@ class HTMLPurifier_AttrDef_HTML_ID extends HTMLPurifier_AttrDef
             return false;
         }
 
-        if (/*!$this->ref && */$result) $id_accumulator->add($id);
+        if (!$this->selector && $result) {
+            $id_accumulator->add($id);
+        }
 
         // if no change was made to the ID, return the result
         // else, return the new id if stripping whitespace made it
         //     valid, or return false.
         return $result ? $id : false;
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/Length.php b/library/HTMLPurifier/AttrDef/HTML/Length.php
index a242f9c23..1c4006fbb 100644
--- a/library/HTMLPurifier/AttrDef/HTML/Length.php
+++ b/library/HTMLPurifier/AttrDef/HTML/Length.php
@@ -10,32 +10,47 @@
 class HTMLPurifier_AttrDef_HTML_Length extends HTMLPurifier_AttrDef_HTML_Pixels
 {
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = trim($string);
-        if ($string === '') return false;
+        if ($string === '') {
+            return false;
+        }
 
         $parent_result = parent::validate($string, $config, $context);
-        if ($parent_result !== false) return $parent_result;
+        if ($parent_result !== false) {
+            return $parent_result;
+        }
 
         $length = strlen($string);
         $last_char = $string[$length - 1];
 
-        if ($last_char !== '%') return false;
+        if ($last_char !== '%') {
+            return false;
+        }
 
         $points = substr($string, 0, $length - 1);
 
-        if (!is_numeric($points)) return false;
-
-        $points = (int) $points;
+        if (!is_numeric($points)) {
+            return false;
+        }
 
-        if ($points < 0) return '0%';
-        if ($points > 100) return '100%';
-
-        return ((string) $points) . '%';
+        $points = (int)$points;
 
+        if ($points < 0) {
+            return '0%';
+        }
+        if ($points > 100) {
+            return '100%';
+        }
+        return ((string)$points) . '%';
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/LinkTypes.php b/library/HTMLPurifier/AttrDef/HTML/LinkTypes.php
index 76d25ed08..63fa04c15 100644
--- a/library/HTMLPurifier/AttrDef/HTML/LinkTypes.php
+++ b/library/HTMLPurifier/AttrDef/HTML/LinkTypes.php
@@ -9,26 +9,44 @@
 class HTMLPurifier_AttrDef_HTML_LinkTypes extends HTMLPurifier_AttrDef
 {
 
-    /** Name config attribute to pull. */
+    /**
+     * Name config attribute to pull.
+     * @type string
+     */
     protected $name;
 
-    public function __construct($name) {
+    /**
+     * @param string $name
+     */
+    public function __construct($name)
+    {
         $configLookup = array(
             'rel' => 'AllowedRel',
             'rev' => 'AllowedRev'
         );
         if (!isset($configLookup[$name])) {
-            trigger_error('Unrecognized attribute name for link '.
-                'relationship.', E_USER_ERROR);
+            trigger_error(
+                'Unrecognized attribute name for link ' .
+                'relationship.',
+                E_USER_ERROR
+            );
             return;
         }
         $this->name = $configLookup[$name];
     }
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $allowed = $config->get('Attr.' . $this->name);
-        if (empty($allowed)) return false;
+        if (empty($allowed)) {
+            return false;
+        }
 
         $string = $this->parseCDATA($string);
         $parts = explode(' ', $string);
@@ -37,17 +55,18 @@ class HTMLPurifier_AttrDef_HTML_LinkTypes extends HTMLPurifier_AttrDef
         $ret_lookup = array();
         foreach ($parts as $part) {
             $part = strtolower(trim($part));
-            if (!isset($allowed[$part])) continue;
+            if (!isset($allowed[$part])) {
+                continue;
+            }
             $ret_lookup[$part] = true;
         }
 
-        if (empty($ret_lookup)) return false;
+        if (empty($ret_lookup)) {
+            return false;
+        }
         $string = implode(' ', array_keys($ret_lookup));
-
         return $string;
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/MultiLength.php b/library/HTMLPurifier/AttrDef/HTML/MultiLength.php
index c72fc76e4..bbb20f2f8 100644
--- a/library/HTMLPurifier/AttrDef/HTML/MultiLength.php
+++ b/library/HTMLPurifier/AttrDef/HTML/MultiLength.php
@@ -9,33 +9,52 @@
 class HTMLPurifier_AttrDef_HTML_MultiLength extends HTMLPurifier_AttrDef_HTML_Length
 {
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = trim($string);
-        if ($string === '') return false;
+        if ($string === '') {
+            return false;
+        }
 
         $parent_result = parent::validate($string, $config, $context);
-        if ($parent_result !== false) return $parent_result;
+        if ($parent_result !== false) {
+            return $parent_result;
+        }
 
         $length = strlen($string);
         $last_char = $string[$length - 1];
 
-        if ($last_char !== '*') return false;
+        if ($last_char !== '*') {
+            return false;
+        }
 
         $int = substr($string, 0, $length - 1);
 
-        if ($int == '') return '*';
-        if (!is_numeric($int)) return false;
-
-        $int = (int) $int;
-
-        if ($int < 0) return false;
-        if ($int == 0) return '0';
-        if ($int == 1) return '*';
-        return ((string) $int) . '*';
-
+        if ($int == '') {
+            return '*';
+        }
+        if (!is_numeric($int)) {
+            return false;
+        }
+
+        $int = (int)$int;
+        if ($int < 0) {
+            return false;
+        }
+        if ($int == 0) {
+            return '0';
+        }
+        if ($int == 1) {
+            return '*';
+        }
+        return ((string)$int) . '*';
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/Nmtokens.php b/library/HTMLPurifier/AttrDef/HTML/Nmtokens.php
index aa34120bd..f79683b4f 100644
--- a/library/HTMLPurifier/AttrDef/HTML/Nmtokens.php
+++ b/library/HTMLPurifier/AttrDef/HTML/Nmtokens.php
@@ -6,24 +6,38 @@
 class HTMLPurifier_AttrDef_HTML_Nmtokens extends HTMLPurifier_AttrDef
 {
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = trim($string);
 
         // early abort: '' and '0' (strings that convert to false) are invalid
-        if (!$string) return false;
+        if (!$string) {
+            return false;
+        }
 
         $tokens = $this->split($string, $config, $context);
         $tokens = $this->filter($tokens, $config, $context);
-        if (empty($tokens)) return false;
+        if (empty($tokens)) {
+            return false;
+        }
         return implode(' ', $tokens);
-
     }
 
     /**
      * Splits a space separated list of tokens into its constituent parts.
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return array
      */
-    protected function split($string, $config, $context) {
+    protected function split($string, $config, $context)
+    {
         // OPTIMIZABLE!
         // do the preg_match, capture all subpatterns for reformulation
 
@@ -31,9 +45,9 @@ class HTMLPurifier_AttrDef_HTML_Nmtokens extends HTMLPurifier_AttrDef
         // escaping because I don't know how to do that with regexps
         // and plus it would complicate optimization efforts (you never
         // see that anyway).
-        $pattern = '/(?:(?<=\s)|\A)'. // look behind for space or string start
-                   '((?:--|-?[A-Za-z_])[A-Za-z_\-0-9]*)'.
-                   '(?:(?=\s)|\z)/'; // look ahead for space or string end
+        $pattern = '/(?:(?<=\s)|\A)' . // look behind for space or string start
+            '((?:--|-?[A-Za-z_])[A-Za-z_\-0-9]*)' .
+            '(?:(?=\s)|\z)/'; // look ahead for space or string end
         preg_match_all($pattern, $string, $matches);
         return $matches[1];
     }
@@ -42,11 +56,15 @@ class HTMLPurifier_AttrDef_HTML_Nmtokens extends HTMLPurifier_AttrDef
      * Template method for removing certain tokens based on arbitrary criteria.
      * @note If we wanted to be really functional, we'd do an array_filter
      *       with a callback. But... we're not.
+     * @param array $tokens
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return array
      */
-    protected function filter($tokens, $config, $context) {
+    protected function filter($tokens, $config, $context)
+    {
         return $tokens;
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/HTML/Pixels.php b/library/HTMLPurifier/AttrDef/HTML/Pixels.php
index 4cb2c1b85..a1d019e09 100644
--- a/library/HTMLPurifier/AttrDef/HTML/Pixels.php
+++ b/library/HTMLPurifier/AttrDef/HTML/Pixels.php
@@ -6,43 +6,71 @@
 class HTMLPurifier_AttrDef_HTML_Pixels extends HTMLPurifier_AttrDef
 {
 
+    /**
+     * @type int
+     */
     protected $max;
 
-    public function __construct($max = null) {
+    /**
+     * @param int $max
+     */
+    public function __construct($max = null)
+    {
         $this->max = $max;
     }
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = trim($string);
-        if ($string === '0') return $string;
-        if ($string === '')  return false;
+        if ($string === '0') {
+            return $string;
+        }
+        if ($string === '') {
+            return false;
+        }
         $length = strlen($string);
         if (substr($string, $length - 2) == 'px') {
             $string = substr($string, 0, $length - 2);
         }
-        if (!is_numeric($string)) return false;
-        $int = (int) $string;
+        if (!is_numeric($string)) {
+            return false;
+        }
+        $int = (int)$string;
 
-        if ($int < 0) return '0';
+        if ($int < 0) {
+            return '0';
+        }
 
         // upper-bound value, extremely high values can
         // crash operating systems, see <http://ha.ckers.org/imagecrash.html>
         // WARNING, above link WILL crash you if you're using Windows
 
-        if ($this->max !== null && $int > $this->max) return (string) $this->max;
-
-        return (string) $int;
-
+        if ($this->max !== null && $int > $this->max) {
+            return (string)$this->max;
+        }
+        return (string)$int;
     }
 
-    public function make($string) {
-        if ($string === '') $max = null;
-        else $max = (int) $string;
+    /**
+     * @param string $string
+     * @return HTMLPurifier_AttrDef
+     */
+    public function make($string)
+    {
+        if ($string === '') {
+            $max = null;
+        } else {
+            $max = (int)$string;
+        }
         $class = get_class($this);
         return new $class($max);
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/Integer.php b/library/HTMLPurifier/AttrDef/Integer.php
index d59738d2a..400e707d2 100644
--- a/library/HTMLPurifier/AttrDef/Integer.php
+++ b/library/HTMLPurifier/AttrDef/Integer.php
@@ -11,17 +11,20 @@ class HTMLPurifier_AttrDef_Integer extends HTMLPurifier_AttrDef
 {
 
     /**
-     * Bool indicating whether or not negative values are allowed
+     * Whether or not negative values are allowed.
+     * @type bool
      */
     protected $negative = true;
 
     /**
-     * Bool indicating whether or not zero is allowed
+     * Whether or not zero is allowed.
+     * @type bool
      */
     protected $zero = true;
 
     /**
-     * Bool indicating whether or not positive values are allowed
+     * Whether or not positive values are allowed.
+     * @type bool
      */
     protected $positive = true;
 
@@ -30,44 +33,59 @@ class HTMLPurifier_AttrDef_Integer extends HTMLPurifier_AttrDef
      * @param $zero Bool indicating whether or not zero is allowed
      * @param $positive Bool indicating whether or not positive values are allowed
      */
-    public function __construct(
-        $negative = true, $zero = true, $positive = true
-    ) {
+    public function __construct($negative = true, $zero = true, $positive = true)
+    {
         $this->negative = $negative;
-        $this->zero     = $zero;
+        $this->zero = $zero;
         $this->positive = $positive;
     }
 
-    public function validate($integer, $config, $context) {
-
+    /**
+     * @param string $integer
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($integer, $config, $context)
+    {
         $integer = $this->parseCDATA($integer);
-        if ($integer === '') return false;
+        if ($integer === '') {
+            return false;
+        }
 
         // we could possibly simply typecast it to integer, but there are
         // certain fringe cases that must not return an integer.
 
         // clip leading sign
-        if ( $this->negative && $integer[0] === '-' ) {
+        if ($this->negative && $integer[0] === '-') {
             $digits = substr($integer, 1);
-            if ($digits === '0') $integer = '0'; // rm minus sign for zero
-        } elseif( $this->positive && $integer[0] === '+' ) {
+            if ($digits === '0') {
+                $integer = '0';
+            } // rm minus sign for zero
+        } elseif ($this->positive && $integer[0] === '+') {
             $digits = $integer = substr($integer, 1); // rm unnecessary plus
         } else {
             $digits = $integer;
         }
 
         // test if it's numeric
-        if (!ctype_digit($digits)) return false;
+        if (!ctype_digit($digits)) {
+            return false;
+        }
 
         // perform scope tests
-        if (!$this->zero     && $integer == 0) return false;
-        if (!$this->positive && $integer > 0) return false;
-        if (!$this->negative && $integer < 0) return false;
+        if (!$this->zero && $integer == 0) {
+            return false;
+        }
+        if (!$this->positive && $integer > 0) {
+            return false;
+        }
+        if (!$this->negative && $integer < 0) {
+            return false;
+        }
 
         return $integer;
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/Lang.php b/library/HTMLPurifier/AttrDef/Lang.php
index 10e6da56d..2a55cea64 100644
--- a/library/HTMLPurifier/AttrDef/Lang.php
+++ b/library/HTMLPurifier/AttrDef/Lang.php
@@ -7,15 +7,25 @@
 class HTMLPurifier_AttrDef_Lang extends HTMLPurifier_AttrDef
 {
 
-    public function validate($string, $config, $context) {
-
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $string = trim($string);
-        if (!$string) return false;
+        if (!$string) {
+            return false;
+        }
 
         $subtags = explode('-', $string);
         $num_subtags = count($subtags);
 
-        if ($num_subtags == 0) return false; // sanity check
+        if ($num_subtags == 0) { // sanity check
+            return false;
+        }
 
         // process primary subtag : $subtags[0]
         $length = strlen($subtags[0]);
@@ -23,15 +33,15 @@ class HTMLPurifier_AttrDef_Lang extends HTMLPurifier_AttrDef
             case 0:
                 return false;
             case 1:
-                if (! ($subtags[0] == 'x' || $subtags[0] == 'i') ) {
+                if (!($subtags[0] == 'x' || $subtags[0] == 'i')) {
                     return false;
                 }
                 break;
             case 2:
             case 3:
-                if (! ctype_alpha($subtags[0]) ) {
+                if (!ctype_alpha($subtags[0])) {
                     return false;
-                } elseif (! ctype_lower($subtags[0]) ) {
+                } elseif (!ctype_lower($subtags[0])) {
                     $subtags[0] = strtolower($subtags[0]);
                 }
                 break;
@@ -40,17 +50,23 @@ class HTMLPurifier_AttrDef_Lang extends HTMLPurifier_AttrDef
         }
 
         $new_string = $subtags[0];
-        if ($num_subtags == 1) return $new_string;
+        if ($num_subtags == 1) {
+            return $new_string;
+        }
 
         // process second subtag : $subtags[1]
         $length = strlen($subtags[1]);
         if ($length == 0 || ($length == 1 && $subtags[1] != 'x') || $length > 8 || !ctype_alnum($subtags[1])) {
             return $new_string;
         }
-        if (!ctype_lower($subtags[1])) $subtags[1] = strtolower($subtags[1]);
+        if (!ctype_lower($subtags[1])) {
+            $subtags[1] = strtolower($subtags[1]);
+        }
 
         $new_string .= '-' . $subtags[1];
-        if ($num_subtags == 2) return $new_string;
+        if ($num_subtags == 2) {
+            return $new_string;
+        }
 
         // process all other subtags, index 2 and up
         for ($i = 2; $i < $num_subtags; $i++) {
@@ -63,11 +79,8 @@ class HTMLPurifier_AttrDef_Lang extends HTMLPurifier_AttrDef
             }
             $new_string .= '-' . $subtags[$i];
         }
-
         return $new_string;
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/Switch.php b/library/HTMLPurifier/AttrDef/Switch.php
index c9e3ed193..c7eb3199a 100644
--- a/library/HTMLPurifier/AttrDef/Switch.php
+++ b/library/HTMLPurifier/AttrDef/Switch.php
@@ -6,21 +6,41 @@
 class HTMLPurifier_AttrDef_Switch
 {
 
+    /**
+     * @type string
+     */
     protected $tag;
-    protected $withTag, $withoutTag;
+
+    /**
+     * @type HTMLPurifier_AttrDef
+     */
+    protected $withTag;
+
+    /**
+     * @type HTMLPurifier_AttrDef
+     */
+    protected $withoutTag;
 
     /**
      * @param string $tag Tag name to switch upon
      * @param HTMLPurifier_AttrDef $with_tag Call if token matches tag
      * @param HTMLPurifier_AttrDef $without_tag Call if token doesn't match, or there is no token
      */
-    public function __construct($tag, $with_tag, $without_tag) {
+    public function __construct($tag, $with_tag, $without_tag)
+    {
         $this->tag = $tag;
         $this->withTag = $with_tag;
         $this->withoutTag = $without_tag;
     }
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $token = $context->get('CurrentToken', true);
         if (!$token || $token->name !== $this->tag) {
             return $this->withoutTag->validate($string, $config, $context);
@@ -28,7 +48,6 @@ class HTMLPurifier_AttrDef_Switch
             return $this->withTag->validate($string, $config, $context);
         }
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/Text.php b/library/HTMLPurifier/AttrDef/Text.php
index c6216cc53..4553a4ea9 100644
--- a/library/HTMLPurifier/AttrDef/Text.php
+++ b/library/HTMLPurifier/AttrDef/Text.php
@@ -6,10 +6,16 @@
 class HTMLPurifier_AttrDef_Text extends HTMLPurifier_AttrDef
 {
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         return $this->parseCDATA($string);
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/URI.php b/library/HTMLPurifier/AttrDef/URI.php
index 01a6d83e9..c1cd89772 100644
--- a/library/HTMLPurifier/AttrDef/URI.php
+++ b/library/HTMLPurifier/AttrDef/URI.php
@@ -7,31 +7,54 @@
 class HTMLPurifier_AttrDef_URI extends HTMLPurifier_AttrDef
 {
 
+    /**
+     * @type HTMLPurifier_URIParser
+     */
     protected $parser;
+
+    /**
+     * @type bool
+     */
     protected $embedsResource;
 
     /**
-     * @param $embeds_resource_resource Does the URI here result in an extra HTTP request?
+     * @param bool $embeds_resource Does the URI here result in an extra HTTP request?
      */
-    public function __construct($embeds_resource = false) {
+    public function __construct($embeds_resource = false)
+    {
         $this->parser = new HTMLPurifier_URIParser();
-        $this->embedsResource = (bool) $embeds_resource;
+        $this->embedsResource = (bool)$embeds_resource;
     }
 
-    public function make($string) {
-        $embeds = (bool) $string;
+    /**
+     * @param string $string
+     * @return HTMLPurifier_AttrDef_URI
+     */
+    public function make($string)
+    {
+        $embeds = ($string === 'embedded');
         return new HTMLPurifier_AttrDef_URI($embeds);
     }
 
-    public function validate($uri, $config, $context) {
-
-        if ($config->get('URI.Disable')) return false;
+    /**
+     * @param string $uri
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($uri, $config, $context)
+    {
+        if ($config->get('URI.Disable')) {
+            return false;
+        }
 
         $uri = $this->parseCDATA($uri);
 
         // parse the URI
         $uri = $this->parser->parse($uri);
-        if ($uri === false) return false;
+        if ($uri === false) {
+            return false;
+        }
 
         // add embedded flag to context for validators
         $context->register('EmbeddedURI', $this->embedsResource);
@@ -41,23 +64,35 @@ class HTMLPurifier_AttrDef_URI extends HTMLPurifier_AttrDef
 
             // generic validation
             $result = $uri->validate($config, $context);
-            if (!$result) break;
+            if (!$result) {
+                break;
+            }
 
             // chained filtering
             $uri_def = $config->getDefinition('URI');
             $result = $uri_def->filter($uri, $config, $context);
-            if (!$result) break;
+            if (!$result) {
+                break;
+            }
 
             // scheme-specific validation
             $scheme_obj = $uri->getSchemeObj($config, $context);
-            if (!$scheme_obj) break;
-            if ($this->embedsResource && !$scheme_obj->browsable) break;
+            if (!$scheme_obj) {
+                break;
+            }
+            if ($this->embedsResource && !$scheme_obj->browsable) {
+                break;
+            }
             $result = $scheme_obj->validate($uri, $config, $context);
-            if (!$result) break;
+            if (!$result) {
+                break;
+            }
 
             // Post chained filtering
             $result = $uri_def->postFilter($uri, $config, $context);
-            if (!$result) break;
+            if (!$result) {
+                break;
+            }
 
             // survived gauntlet
             $ok = true;
@@ -65,13 +100,12 @@ class HTMLPurifier_AttrDef_URI extends HTMLPurifier_AttrDef
         } while (false);
 
         $context->destroy('EmbeddedURI');
-        if (!$ok) return false;
-
+        if (!$ok) {
+            return false;
+        }
         // back to string
         return $uri->toString();
-
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/URI/Email.php b/library/HTMLPurifier/AttrDef/URI/Email.php
index bfee9d166..daf32b764 100644
--- a/library/HTMLPurifier/AttrDef/URI/Email.php
+++ b/library/HTMLPurifier/AttrDef/URI/Email.php
@@ -5,8 +5,11 @@ abstract class HTMLPurifier_AttrDef_URI_Email extends HTMLPurifier_AttrDef
 
     /**
      * Unpacks a mailbox into its display-name and address
+     * @param string $string
+     * @return mixed
      */
-    function unpack($string) {
+    public function unpack($string)
+    {
         // needs to be implemented
     }
 
diff --git a/library/HTMLPurifier/AttrDef/URI/Email/SimpleCheck.php b/library/HTMLPurifier/AttrDef/URI/Email/SimpleCheck.php
index 94c715ab4..52c0d5968 100644
--- a/library/HTMLPurifier/AttrDef/URI/Email/SimpleCheck.php
+++ b/library/HTMLPurifier/AttrDef/URI/Email/SimpleCheck.php
@@ -7,15 +7,23 @@
 class HTMLPurifier_AttrDef_URI_Email_SimpleCheck extends HTMLPurifier_AttrDef_URI_Email
 {
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         // no support for named mailboxes i.e. "Bob <bob@example.com>"
         // that needs more percent encoding to be done
-        if ($string == '') return false;
+        if ($string == '') {
+            return false;
+        }
         $string = trim($string);
         $result = preg_match('/^[A-Z0-9._%-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i', $string);
         return $result ? $string : false;
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/URI/Host.php b/library/HTMLPurifier/AttrDef/URI/Host.php
index 2156c10c6..e7df800b1 100644
--- a/library/HTMLPurifier/AttrDef/URI/Host.php
+++ b/library/HTMLPurifier/AttrDef/URI/Host.php
@@ -7,56 +7,122 @@ class HTMLPurifier_AttrDef_URI_Host extends HTMLPurifier_AttrDef
 {
 
     /**
-     * Instance of HTMLPurifier_AttrDef_URI_IPv4 sub-validator
+     * IPv4 sub-validator.
+     * @type HTMLPurifier_AttrDef_URI_IPv4
      */
     protected $ipv4;
 
     /**
-     * Instance of HTMLPurifier_AttrDef_URI_IPv6 sub-validator
+     * IPv6 sub-validator.
+     * @type HTMLPurifier_AttrDef_URI_IPv6
      */
     protected $ipv6;
 
-    public function __construct() {
+    public function __construct()
+    {
         $this->ipv4 = new HTMLPurifier_AttrDef_URI_IPv4();
         $this->ipv6 = new HTMLPurifier_AttrDef_URI_IPv6();
     }
 
-    public function validate($string, $config, $context) {
+    /**
+     * @param string $string
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($string, $config, $context)
+    {
         $length = strlen($string);
-        if ($string === '') return '';
-        if ($length > 1 && $string[0] === '[' && $string[$length-1] === ']') {
+        // empty hostname is OK; it's usually semantically equivalent:
+        // the default host as defined by a URI scheme is used:
+        //
+        //      If the URI scheme defines a default for host, then that
+        //      default applies when the host subcomponent is undefined
+        //      or when the registered name is empty (zero length).
+        if ($string === '') {
+            return '';
+        }
+        if ($length > 1 && $string[0] === '[' && $string[$length - 1] === ']') {
             //IPv6
             $ip = substr($string, 1, $length - 2);
             $valid = $this->ipv6->validate($ip, $config, $context);
-            if ($valid === false) return false;
-            return '['. $valid . ']';
+            if ($valid === false) {
+                return false;
+            }
+            return '[' . $valid . ']';
         }
 
         // need to do checks on unusual encodings too
         $ipv4 = $this->ipv4->validate($string, $config, $context);
-        if ($ipv4 !== false) return $ipv4;
+        if ($ipv4 !== false) {
+            return $ipv4;
+        }
 
         // A regular domain name.
 
-        // This breaks I18N domain names, but we don't have proper IRI support,
-        // so force users to insert Punycode. If there's complaining we'll
-        // try to fix things into an international friendly form.
+        // This doesn't match I18N domain names, but we don't have proper IRI support,
+        // so force users to insert Punycode.
+
+        // There is not a good sense in which underscores should be
+        // allowed, since it's technically not! (And if you go as
+        // far to allow everything as specified by the DNS spec...
+        // well, that's literally everything, modulo some space limits
+        // for the components and the overall name (which, by the way,
+        // we are NOT checking!).  So we (arbitrarily) decide this:
+        // let's allow underscores wherever we would have allowed
+        // hyphens, if they are enabled.  This is a pretty good match
+        // for browser behavior, for example, a large number of browsers
+        // cannot handle foo_.example.com, but foo_bar.example.com is
+        // fairly well supported.
+        $underscore = $config->get('Core.AllowHostnameUnderscore') ? '_' : '';
 
         // The productions describing this are:
         $a   = '[a-z]';     // alpha
         $an  = '[a-z0-9]';  // alphanum
-        $and = '[a-z0-9-]'; // alphanum | "-"
+        $and = "[a-z0-9-$underscore]"; // alphanum | "-"
         // domainlabel = alphanum | alphanum *( alphanum | "-" ) alphanum
-        $domainlabel   = "$an($and*$an)?";
+        $domainlabel = "$an($and*$an)?";
         // toplabel    = alpha | alpha *( alphanum | "-" ) alphanum
-        $toplabel      = "$a($and*$an)?";
+        $toplabel = "$a($and*$an)?";
         // hostname    = *( domainlabel "." ) toplabel [ "." ]
-        $match = preg_match("/^($domainlabel\.)*$toplabel\.?$/i", $string);
-        if (!$match) return false;
+        if (preg_match("/^($domainlabel\.)*$toplabel\.?$/i", $string)) {
+            return $string;
+        }
 
-        return $string;
-    }
+        // If we have Net_IDNA2 support, we can support IRIs by
+        // punycoding them. (This is the most portable thing to do,
+        // since otherwise we have to assume browsers support
 
+        if ($config->get('Core.EnableIDNA')) {
+            $idna = new Net_IDNA2(array('encoding' => 'utf8', 'overlong' => false, 'strict' => true));
+            // we need to encode each period separately
+            $parts = explode('.', $string);
+            try {
+                $new_parts = array();
+                foreach ($parts as $part) {
+                    $encodable = false;
+                    for ($i = 0, $c = strlen($part); $i < $c; $i++) {
+                        if (ord($part[$i]) > 0x7a) {
+                            $encodable = true;
+                            break;
+                        }
+                    }
+                    if (!$encodable) {
+                        $new_parts[] = $part;
+                    } else {
+                        $new_parts[] = $idna->encode($part);
+                    }
+                }
+                $string = implode('.', $new_parts);
+                if (preg_match("/^($domainlabel\.)*$toplabel\.?$/i", $string)) {
+                    return $string;
+                }
+            } catch (Exception $e) {
+                // XXX error reporting
+            }
+        }
+        return false;
+    }
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/URI/IPv4.php b/library/HTMLPurifier/AttrDef/URI/IPv4.php
index ec4cf591b..30ac16c9e 100644
--- a/library/HTMLPurifier/AttrDef/URI/IPv4.php
+++ b/library/HTMLPurifier/AttrDef/URI/IPv4.php
@@ -8,32 +8,38 @@ class HTMLPurifier_AttrDef_URI_IPv4 extends HTMLPurifier_AttrDef
 {
 
     /**
-     * IPv4 regex, protected so that IPv6 can reuse it
+     * IPv4 regex, protected so that IPv6 can reuse it.
+     * @type string
      */
     protected $ip4;
 
-    public function validate($aIP, $config, $context) {
-
-        if (!$this->ip4) $this->_loadRegex();
-
-        if (preg_match('#^' . $this->ip4 . '$#s', $aIP))
-        {
-                return $aIP;
+    /**
+     * @param string $aIP
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($aIP, $config, $context)
+    {
+        if (!$this->ip4) {
+            $this->_loadRegex();
         }
 
+        if (preg_match('#^' . $this->ip4 . '$#s', $aIP)) {
+            return $aIP;
+        }
         return false;
-
     }
 
     /**
      * Lazy load function to prevent regex from being stuffed in
      * cache.
      */
-    protected function _loadRegex() {
+    protected function _loadRegex()
+    {
         $oct = '(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])'; // 0-255
         $this->ip4 = "(?:{$oct}\\.{$oct}\\.{$oct}\\.{$oct})";
     }
-
 }
 
 // vim: et sw=4 sts=4
diff --git a/library/HTMLPurifier/AttrDef/URI/IPv6.php b/library/HTMLPurifier/AttrDef/URI/IPv6.php
index 9454e9be5..f243793ee 100644
--- a/library/HTMLPurifier/AttrDef/URI/IPv6.php
+++ b/library/HTMLPurifier/AttrDef/URI/IPv6.php
@@ -9,91 +9,81 @@
 class HTMLPurifier_AttrDef_URI_IPv6 extends HTMLPurifier_AttrDef_URI_IPv4
 {
 
-    public function validate($aIP, $config, $context) {
-
-        if (!$this->ip4) $this->_loadRegex();
+    /**
+     * @param string $aIP
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool|string
+     */
+    public function validate($aIP, $config, $context)
+    {
+        if (!$this->ip4) {
+            $this->_loadRegex();
+        }
 
         $original = $aIP;
 
         $hex = '[0-9a-fA-F]';
         $blk = '(?:' . $hex . '{1,4})';
-        $pre = '(?:/(?:12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9]))';   // /0 - /128
+        $pre = '(?:/(?:12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9]))'; // /0 - /128
 
         //      prefix check
-        if (strpos($aIP, '/') !== false)
-        {
-                if (preg_match('#' . $pre . '$#s', $aIP, $find))
-                {
-                        $aIP = substr($aIP, 0, 0-strlen($find[0]));
-                        unset($find);
-                }
-                else
-                {
-                        return false;
-                }
+        if (strpos($aIP, '/') !== false) {
+            if (preg_match('#' . $pre . '$#s', $aIP, $find)) {
+                $aIP = substr($aIP, 0, 0 - strlen($find[0]));
+                unset($find);
+            } else {
+                return false;
+            }
         }
 
         //      IPv4-compatiblity check
-        if (preg_match('#(?<=:'.')' . $this->ip4 . '$#s', $aIP, $find))
-        {
-                $aIP = substr($aIP, 0, 0-strlen($find[0]));
-                $ip = explode('.', $find[0]);
-                $ip = array_map('dechex', $ip);
-                $aIP .= $ip[0] . $ip[1] . ':' . $ip[2] . $ip[3];
-                unset($find, $ip);
+        if (preg_match('#(?<=:' . ')' . $this->ip4 . '$#s', $aIP, $find)) {
+            $aIP = substr($aIP, 0, 0 - strlen($find[0]));
+            $ip = explode('.', $find[0]);
+            $ip = array_map('dechex', $ip);
+            $aIP .= $ip[0] . $ip[1] . ':' . $ip[2] . $ip[3];
+            unset($find, $ip);
         }
 
         //      compression check
         $aIP = explode('::', $aIP);
         $c = count($aIP);
-        if ($c > 2)
-        {
+        if ($c > 2) {
+            return false;
+        } elseif ($c == 2) {
+            list($first, $second) = $aIP;
+            $first = explode(':', $first);
+            $second = explode(':', $second);
+
+            if (count($first) + count($second) > 8) {
                 return false;
-        }
-        elseif ($c == 2)
-        {
-                list($first, $second) = $aIP;
-                $first = explode(':', $first);
-                $second = explode(':', $second);
-
-                if (count($first) + count($second) > 8)
-                {
-                        return false;
-                }
+            }
 
-                while(count($first) < 8)
-                {
-                        array_push($first, '0');
-                }
+            while (count($first) < 8) {
+                array_push($first, '0');
+            }
 
-                array_splice($first, 8 - count($second), 8, $second);
-                $aIP = $first;
-                unset($first,$second);
-        }
-        else
-        {
-                $aIP = explode(':', $aIP[0]);
+            array_splice($first, 8 - count($second), 8, $second);
+            $aIP = $first;
+            unset($first, $second);
+        } else {
+            $aIP = explode(':', $aIP[0]);
         }
         $c = count($aIP);
 
-        if ($c != 8)
-        {
-                return false;
+        if ($c != 8) {
+            return false;
         }
 
         //      All the pieces should be 16-bit hex strings. Are they?
-        foreach ($aIP as $piece)
-        {
-                if (!preg_match('#^[0-9a-fA-F]{4}$#s', sprintf('%04s', $piece)))
-                {
-                        return false;
-                }
+        foreach ($aIP as $piece) {
+            if (!preg_match('#^[0-9a-fA-F]{4}$#s', sprintf('%04s', $piece))) {
+                return false;
+            }
         }
-
         return $original;
-
     }
-
 }
 
 // vim: et sw=4 sts=4