Changeset 33359 for trunk/src/wp-includes/shortcodes.php

Timestamp:

07/22/2015 05:14:50 AM (9 years ago)

Author:

pento

Message:

Shortcodes: Improve the reliablity of shortcodes inside HTML tags.

Props miqrogroove.

See #15694.

File:

• trunk/src/wp-includes/shortcodes.php (modified) (4 diffs)

trunk/src/wp-includes/shortcodes.php

@@ -183 +183 @@
  *
  * @param string $content Content to search for shortcodes.
+ * @param bool $ignore_html When true, shortcodes inside HTML elements will be skipped.
  * @return string Content with shortcodes filtered out.
  */
-function do_shortcode($content) {
+function do_shortcode( $content, $ignore_html = false ) {
     global $shortcode_tags;
 
@@ -195 +196 @@
         return $content;
 
+    $tagnames = array_keys($shortcode_tags);
+    $tagregexp = join( '|', array_map('preg_quote', $tagnames) );
+    $pattern = "/\\[($tagregexp)/s";
+
+    if ( 1 !== preg_match( $pattern, $content ) ) {
+        // Avoids parsing HTML when there are no shortcodes or embeds anyway.
+        return $content;
+    }
+
+    $content = do_shortcodes_in_html_tags( $content, $ignore_html );
+
     $pattern = get_shortcode_regex();
-    return preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $content );
+    $content = preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $content );
+    
+    // Always restore square braces so we don't break things like <!--[if IE ]>
+    $content = unescape_invalid_shortcodes( $content );
+    
+    return $content;
 }
 
@@ -297 +314 @@
 
 /**
+ * Search only inside HTML elements for shortcodes and process them.
+ *
+ * Any [ or ] characters remaining inside elements will be HTML encoded
+ * to prevent interference with shortcodes that are outside the elements.
+ * Assumes $content processed by KSES already.  Users with unfiltered_html
+ * capability may get unexpected output if angle braces are nested in tags.
+ *
+ * @since 4.2.3
+ *
+ * @param string $content Content to search for shortcodes
+ * @param bool $ignore_html When true, all square braces inside elements will be encoded.
+ * @return string Content with shortcodes filtered out.
+ */
+function do_shortcodes_in_html_tags( $content, $ignore_html ) {
+    // Normalize entities in unfiltered HTML before adding placeholders.
+    $trans = array( '&#91;' => '&#091;', '&#93;' => '&#093;' );
+    $content = strtr( $content, $trans );
+    $trans = array( '[' => '&#91;', ']' => '&#93;' );
+    
+    $pattern = get_shortcode_regex();
+
+    $comment_regex =
+          '!'           // Start of comment, after the <.
+        . '(?:'         // Unroll the loop: Consume everything until --> is found.
+        .     '-(?!->)' // Dash not followed by end of comment.
+        .     '[^\-]*+' // Consume non-dashes.
+        . ')*+'         // Loop possessively.
+        . '(?:-->)?';   // End of comment. If not found, match all input.
+
+    $regex =
+          '/('                   // Capture the entire match.
+        .     '<'                // Find start of element.
+        .     '(?(?=!--)'        // Is this a comment?
+        .         $comment_regex // Find end of comment.
+        .     '|'
+        .         '[^>]*>?'      // Find end of element. If not found, match all input.
+        .     ')'
+        . ')/s';
+
+    $textarr = preg_split( $regex, $content, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
+
+    foreach ( $textarr as &$element ) {
+        if ( '<' !== $element[0] ) {
+            continue;
+        }
+
+        $noopen = false === strpos( $element, '[' );
+        $noclose = false === strpos( $element, ']' );
+        if ( $noopen || $noclose ) {
+            // This element does not contain shortcodes.
+            if ( $noopen xor $noclose ) {
+                // Need to encode stray [ or ] chars.
+                $element = strtr( $element, $trans );
+            }
+            continue;
+        }
+
+        if ( $ignore_html || '<!--' === substr( $element, 0, 4 ) ) {
+            // Encode all [ and ] chars.
+            $element = strtr( $element, $trans );
+            continue;
+        }
+
+        $attributes = wp_kses_attr_parse( $element );
+        if ( false === $attributes ) {
+            // Looks like we found some crazy unfiltered HTML.  Skipping it for sanity.
+            $element = strtr( $element, $trans );
+            continue;
+        }
+        
+        // Get element name
+        $front = array_shift( $attributes );
+        $back = array_pop( $attributes );
+        $matches = array();
+        preg_match('%[a-zA-Z0-9]+%', $front, $matches);
+        $elname = $matches[0];
+        
+        // Look for shortcodes in each attribute separately.
+        foreach ( $attributes as &$attr ) {
+            $open = strpos( $attr, '[' );
+            $close = strpos( $attr, ']' );
+            if ( false === $open || false === $close ) {
+                continue; // Go to next attribute.  Square braces will be escaped at end of loop.
+            }
+            $double = strpos( $attr, '"' );
+            $single = strpos( $attr, "'" );
+            if ( ( false === $single || $open < $single ) && ( false === $double || $open < $double ) ) {
+                // $attr like '[shortcode]' or 'name = [shortcode]' implies unfiltered_html.
+                // In this specific situation we assume KSES did not run because the input
+                // was written by an administrator, so we should avoid changing the output
+                // and we do not need to run KSES here.
+                $attr = preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $attr );
+            } else {
+                // $attr like 'name = "[shortcode]"' or "name = '[shortcode]'"
+                // We do not know if $content was unfiltered. Assume KSES ran before shortcodes.
+                $count = 0;
+                $new_attr = preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $attr, -1, $count );
+                if ( $count > 0 ) {
+                    // Sanitize the shortcode output using KSES.
+                    $new_attr = wp_kses_one_attr( $new_attr, $elname );
+                    if ( '' !== $new_attr ) {
+                        // The shortcode is safe to use now.
+                        $attr = $new_attr;
+                    }
+                }
+            }
+        }
+        $element = $front . implode( '', $attributes ) . $back;
+        
+        // Now encode any remaining [ or ] chars.
+        $element = strtr( $element, $trans );
+    }
+    
+    $content = implode( '', $textarr );
+    
+    return $content;
+}
+
+/**
+ * Remove placeholders added by do_shortcodes_in_html_tags().
+ *
+ * @since 4.2.3
+ *
+ * @param string $content Content to search for placeholders.
+ * @return string Content with placeholders removed.
+ */
+function unescape_invalid_shortcodes( $content ) {
+        // Clean up entire string, avoids re-parsing HTML.
+        $trans = array( '&#91;' => '[', '&#93;' => ']' );
+        $content = strtr( $content, $trans );
+        
+        return $content;
+}
+
+/**
  * Retrieve all attributes from the shortcodes tag.
  *
@@ -395 +547 @@
         return $content;
 
+    $content = do_shortcodes_in_html_tags( $content, true );
+
     $pattern = get_shortcode_regex();
-
-    return preg_replace_callback( "/$pattern/s", 'strip_shortcode_tag', $content );
+    $content = preg_replace_callback( "/$pattern/s", 'strip_shortcode_tag', $content );
+
+    // Always restore square braces so we don't break things like <!--[if IE ]>
+    $content = unescape_invalid_shortcodes( $content );
+    
+    return $content;
 }