Ticket #6518: shortcode-escaping-r7583.patch

wordpress/wp-includes/shortcodes.php

@@ -75 +75 @@
         $tagnames = array_keys($shortcode_tags);
         $tagregexp = join( '|', array_map('preg_quote', $tagnames) );
 
-        $pattern = '/\[('.$tagregexp.')\b(.*?)(?:(\/))?\](?:(.+?)\[\/\1\])?/s';
+        $pattern = '/(.?)\[('.$tagregexp.')\b(.*?)(?:(\/))?\](?:(.+?)\[\/\2\])?(.?)/s';
 
         return preg_replace_callback($pattern, 'do_shortcode_tag', $content);
 }
 
 function do_shortcode_tag($m) {
         global $shortcode_tags;
+        
+        // allow [[foo]] syntax for escaping a tag
+        if ($m[1] == '[' && $m[6] == ']') {
+                return substr($m[0], 1, -1);
+        }
 
-        $tag = $m[1];
-        $attr = shortcode_parse_atts($m[2]);
+        $tag = $m[2];
+        $attr = shortcode_parse_atts($m[3]);
 
-        if ( isset($m[4]) ) {
+        if ( isset($m[5]) ) {
                 // enclosing tag - extra parameter
-                return call_user_func($shortcode_tags[$tag], $attr, $m[4]);
+                return $m[1] . call_user_func($shortcode_tags[$tag], $attr, $m[5]) . $m[6];
         } else {
                 // self-closing tag
-                return call_user_func($shortcode_tags[$tag], $attr);
+                return $m[1] . call_user_func($shortcode_tags[$tag], $attr) . $m[6];
         }
 }