Index: modules/block/block.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/block/block.module,v
retrieving revision 1.300
diff -u -p -r1.300 block.module
--- modules/block/block.module	20 Feb 2008 13:46:38 -0000	1.300
+++ modules/block/block.module	26 Feb 2008 13:48:54 -0000
@@ -215,7 +215,7 @@ function block_block($op = 'list', $delt
 
     case 'view':
       $block = db_fetch_object(db_query('SELECT body, format FROM {boxes} WHERE bid = %d', $delta));
-      $data['content'] = check_markup($block->body, $block->format, FALSE);
+      $data['content'] = apply_filters($block->body, array('block' => $block), $block->format, FALSE);
       return $data;
   }
 }
Index: modules/comment/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment/comment.module,v
retrieving revision 1.621
diff -u -p -r1.621 comment.module
--- modules/comment/comment.module	23 Feb 2008 08:02:48 -0000	1.621
+++ modules/comment/comment.module	26 Feb 2008 13:48:54 -0000
@@ -638,7 +638,7 @@ function comment_nodeapi(&$node, $op, $a
       $text = '';
       $comments = db_query('SELECT subject, comment, format FROM {comments} WHERE nid = %d AND status = %d', $node->nid, COMMENT_PUBLISHED);
       while ($comment = db_fetch_object($comments)) {
-        $text .= '<h2>'. check_plain($comment->subject) .'</h2>'. check_markup($comment->comment, $comment->format, FALSE);
+        $text .= '<h2>'. check_plain($comment->subject) .'</h2>'. apply_filters($comment->comment, array('comment' => $comment), $comment->format, FALSE);
       }
       return $text;
 
@@ -1542,8 +1542,8 @@ function _comment_form_submit(&$comment_
     // 1) Filter it into HTML
     // 2) Strip out all HTML tags
     // 3) Convert entities back to plain-text.
-    // Note: format is checked by check_markup().
-    $comment_values['subject'] = trim(truncate_utf8(decode_entities(strip_tags(check_markup($comment_values['comment'], $comment_values['format']))), 29, TRUE));
+    // Note: format is checked by apply_filters().
+    $comment_values['subject'] = trim(truncate_utf8(decode_entities(strip_tags(apply_filters($comment_values['comment'], NULL, $comment_values['format']))), 29, TRUE));
     // Edge cases where the comment body is populated only by HTML tags will
     // require a default subject.
     if ($comment_values['subject'] == '') {
@@ -1594,7 +1594,7 @@ function theme_comment_view($comment, $n
 
   // Switch to folded/unfolded view of the comment
   if ($visible) {
-    $comment->comment = check_markup($comment->comment, $comment->format, FALSE);
+    $comment->comment = apply_filters($comment->comment, array('comment' => $comment), $comment->format, FALSE);
 
     // Comment API hook
     comment_invoke_comment($comment, 'view');
Index: modules/filter/filter.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/filter/filter.module,v
retrieving revision 1.206
diff -u -p -r1.206 filter.module
--- modules/filter/filter.module	20 Feb 2008 13:46:39 -0000	1.206
+++ modules/filter/filter.module	26 Feb 2008 13:48:54 -0000
@@ -407,6 +407,10 @@ function filter_list_format($format) {
  *
  * @param $text
  *    The text to be filtered.
+ * @param $context
+ *    The context in which the text is filtered. This is an array which has either
+ *    'node' set to a node object, 'comment' set to a comment object or 'block'
+ *    set to the block in which the text occurs.
  * @param $format
  *    The format of the text to be filtered. Specify FILTER_FORMAT_DEFAULT for
  *    the default format.
@@ -417,7 +421,7 @@ function filter_list_format($format) {
  *    showing content that is not (yet) stored in the database (eg. upon preview),
  *    set to TRUE so the user's permissions are checked.
  */
-function check_markup($text, $format = FILTER_FORMAT_DEFAULT, $check = TRUE) {
+function apply_filters($text, $context = NULL, $format = FILTER_FORMAT_DEFAULT, $check = TRUE) {
   // When $check = TRUE, do an access check on $format.
   if (isset($text) && (!$check || filter_access($format))) {
     $format = filter_resolve_format($format);
@@ -440,12 +444,12 @@ function check_markup($text, $format = F
 
     // Give filters the chance to escape HTML-like data such as code or formulas.
     foreach ($filters as $filter) {
-      $text = module_invoke($filter->module, 'filter', 'prepare', $filter->delta, $format, $text, $cache_id);
+      $text = module_invoke($filter->module, 'filter', 'prepare', $filter->delta, $format, $text, $context, $cache_id);
     }
 
     // Perform filtering.
     foreach ($filters as $filter) {
-      $text = module_invoke($filter->module, 'filter', 'process', $filter->delta, $format, $text, $cache_id);
+      $text = module_invoke($filter->module, 'filter', 'process', $filter->delta, $format, $text, $context, $cache_id);
     }
 
     // Store in cache with a minimum expiration time of 1 day.
@@ -600,7 +604,7 @@ function theme_filter_tips_more_info() {
  * - URL and e-mail address filter:
  *     Converts newlines into paragraph and break tags.
  */
-function filter_filter($op, $delta = 0, $format = -1, $text = '') {
+function filter_filter($op, $delta = 0, $format = -1, $text = '', $context = NULL) {
   switch ($op) {
     case 'list':
       return array(0 => t('HTML filter'), 1 => t('Line break converter'), 2 => t('URL filter'), 3 => t('HTML corrector'));
Index: modules/node/node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.module,v
retrieving revision 1.950
diff -u -p -r1.950 node.module
--- modules/node/node.module	20 Feb 2008 13:46:40 -0000	1.950
+++ modules/node/node.module	26 Feb 2008 13:48:55 -0000
@@ -1035,10 +1035,10 @@ function node_prepare($node, $teaser = F
   $node->readmore = (strlen($node->teaser) < strlen($node->body));
 
   if ($teaser == FALSE) {
-    $node->body = check_markup($node->body, $node->format, FALSE);
+    $node->body = apply_filters($node->body, array('node' => $node), $node->format, FALSE);
   }
   else {
-    $node->teaser = check_markup($node->teaser, $node->format, FALSE);
+    $node->teaser = apply_filters($node->teaser, array('node' => $node), $node->format, FALSE);
   }
 
   $node->content['body'] = array(
Index: modules/php/php.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/php/php.module,v
retrieving revision 1.9
diff -u -p -r1.9 php.module
--- modules/php/php.module	10 Feb 2008 19:57:20 -0000	1.9
+++ modules/php/php.module	26 Feb 2008 13:48:55 -0000
@@ -69,7 +69,7 @@ else {
  *
  * Executes PHP code. Use with care.
  */
-function php_filter($op, $delta = 0, $format = -1, $text = '') {
+function php_filter($op, $delta = 0, $format = -1, $text = '', $context = NULL) {
   switch ($op) {
     case 'list':
       return array(0 => t('PHP evaluator'));
Index: modules/profile/profile.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/profile/profile.module,v
retrieving revision 1.236
diff -u -p -r1.236 profile.module
--- modules/profile/profile.module	3 Feb 2008 19:36:46 -0000	1.236
+++ modules/profile/profile.module	26 Feb 2008 13:48:55 -0000
@@ -254,7 +254,7 @@ function profile_view_field($user, $fiel
   if (isset($user->{$field->name}) && $value = $user->{$field->name}) {
     switch ($field->type) {
       case 'textarea':
-        return check_markup($value);
+        return apply_filters($value);
       case 'textfield':
       case 'selection':
         return $browse ? l($value, 'profile/'. $field->name .'/'. $value) : check_plain($value);
Index: modules/user/user.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.module,v
retrieving revision 1.896
diff -u -p -r1.896 user.module
--- modules/user/user.module	20 Feb 2008 13:46:43 -0000	1.896
+++ modules/user/user.module	26 Feb 2008 13:48:55 -0000
@@ -1965,7 +1965,7 @@ function user_comment(&$comment, $op) {
   // Validate signature.
   if ($op == 'view') {
     if (variable_get('user_signatures', 0) && !empty($comment->signature)) {
-      $comment->signature = check_markup($comment->signature, $comment->format);
+      $comment->signature = apply_filters($comment->signature, array('comment' => $comment), $comment->format);
     }
     else {
       $comment->signature = '';