Changeset 18952

Timestamp:

10/12/2011 04:50:30 PM (13 years ago)

Author:

ryan

Message:

Avoid preg backtrack limit errors with large posts when processing shortcodes. Props mdawaffe. fixes #15600

Location:

trunk/wp-includes

Files:

• formatting.php (modified) (1 diff)
• shortcodes.php (modified) (4 diffs)

trunk/wp-includes/formatting.php

@@ -233 +233 @@
  * @return string The filtered content.
  */
-function shortcode_unautop($pee) {
+function shortcode_unautop( $pee ) {
     global $shortcode_tags;
 
-    if ( !empty($shortcode_tags) && is_array($shortcode_tags) ) {
-        $tagnames = array_keys($shortcode_tags);
-        $tagregexp = join( '|', array_map('preg_quote', $tagnames) );
-        $pee = preg_replace('/<p>\\s*?(\\[(' . $tagregexp . ')\\b.*?\\/?\\](?:.+?\\[\\/\\2\\])?)\\s*<\\/p>/s', '$1', $pee);
-    }
-
-    return $pee;
+    if ( empty( $shortcode_tags ) || !is_array( $shortcode_tags ) ) {
+        return $pee;
+    }
+
+    $tagregexp = join( '|', array_map( 'preg_quote', array_keys( $shortcode_tags ) ) );
+
+    $pattern =
+          '/'
+        . '<p>'                              // Opening paragraph
+        . '\\s*+'                            // Optional leading whitespace
+        . '('                                // 1: The shortcode
+        .     '\\['                          // Opening bracket
+        .     "($tagregexp)"                 // 2: Shortcode name
+        .     '\\b'                          // Word boundary
+                                             // Unroll the loop: Inside the opening shortcode tag
+        .     '[^\\]\\/]*'                   // Not a closing bracket or forward slash
+        .     '(?:'
+        .         '\\/(?!\\])'               // A forward slash not followed by a closing bracket
+        .         '[^\\]\\/]*'               // Not a closing bracket or forward slash
+        .     ')*?'
+        .     '(?:'
+        .         '\\/\\]'                   // Self closing tag and closing bracket
+        .     '|'
+        .         '\\]'                      // Closing bracket
+        .         '(?:'                      // Unroll the loop: Optionally, anything between the opening and closing shortcode tags
+        .             '[^\\[]*+'             // Not an opening bracket
+        .             '(?:'
+        .                 '\\[(?!\\/\\2\\])' // An opening bracket not followed by the closing shortcode tag
+        .                 '[^\\[]*+'         // Not an opening bracket
+        .             ')*+'
+        .             '\\[\\/\\2\\]'         // Closing shortcode tag
+        .         ')?'
+        .     ')'
+        . ')'
+        . '\\s*+'                            // optional trailing whitespace
+        . '<\\/p>'                           // closing paragraph
+        . '/s';
+
+    return preg_replace( $pattern, '$1', $pee );
 }
 

trunk/wp-includes/shortcodes.php

@@ -149 +149 @@
 
     $pattern = get_shortcode_regex();
-    return preg_replace_callback('/'.$pattern.'/s', 'do_shortcode_tag', $content);
+    return preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $content );
 }
 
@@ -160 +160 @@
  * The regular expression contains 6 different sub matches to help with parsing.
  *
- * 1/6 - An extra [ or ] to allow for escaping shortcodes with double [[]]
+ * 1 - An extra [ to allow for escaping shortcodes with double [[]]
  * 2 - The shortcode name
  * 3 - The shortcode argument list
  * 4 - The self closing /
  * 5 - The content of a shortcode when it wraps some content.
+ * 6 - An extra ] to allow for escaping shortcodes with double [[]]
  *
  * @since 2.5
@@ -176 +177 @@
     $tagregexp = join( '|', array_map('preg_quote', $tagnames) );
 
-    // WARNING! Do not change this regex without changing do_shortcode_tag() and strip_shortcodes()
-    return '(.?)\[('.$tagregexp.')\b(.*?)(?:(\/))?\](?:(.+?)\[\/\2\])?(.?)';
+    // WARNING! Do not change this regex without changing do_shortcode_tag() and strip_shortcode_tag()
+    return
+          '\\['                              // Opening bracket
+        . '(\\[?)'                           // 1: Optional second opening bracket for escaping shortcodes: [[tag]]
+        . "($tagregexp)"                     // 2: Shortcode name
+        . '\\b'                              // Word boundary
+        . '('                                // 3: Unroll the loop: Inside the opening shortcode tag
+        .     '[^\\]\\/]*'                   // Not a closing bracket or forward slash
+        .     '(?:'
+        .         '\\/(?!\\])'               // A forward slash not followed by a closing bracket
+        .         '[^\\]\\/]*'               // Not a closing bracket or forward slash
+        .     ')*?'
+        . ')'
+        . '(?:'
+        .     '(\\/)'                        // 4: Self closing tag ...
+        .     '\\]'                          // ... and closing bracket
+        . '|'
+        .     '\\]'                          // Closing bracket
+        .     '(?:'
+        .         '('                        // 5: Unroll the loop: Optionally, anything between the opening and closing shortcode tags
+        .             '[^\\[]*+'             // Not an opening bracket
+        .             '(?:'
+        .                 '\\[(?!\\/\\2\\])' // An opening bracket not followed by the closing shortcode tag
+        .                 '[^\\[]*+'         // Not an opening bracket
+        .             ')*+'
+        .         ')'
+        .         '\\[\\/\\2\\]'             // Closing shortcode tag
+        .     ')?'
+        . ')'
+        . '(\\]?)';                          // 6: Optional second closing brocket for escaping shortcodes: [[tag]]
 }
 
@@ -291 +320 @@
     $pattern = get_shortcode_regex();
 
-    return preg_replace('/'.$pattern.'/s', '$1$6', $content);
+    return preg_replace_callback( "/$pattern/s", 'strip_shortcode_tag', $content );
+}
+
+function strip_shortcode_tag( $m ) {
+    // allow [[foo]] syntax for escaping a tag
+    if ( $m[1] == '[' && $m[6] == ']' ) {
+        return substr($m[0], 1, -1);
+    }
+
+    return $m[1] . $m[6];
 }