Extra escape escaped shortcodes

When do_shortcode(), it converts [[shortcode]] to [shortcode] for any registered shortcodes. This allows you to do things like [[gallery]] in your post content and have it show up in the post rendered as [gallery] instead of actual gallery HTML.

However since we're running do_shortcode() early and then do_shortcode() will run again a second time at the normal priority, we need to add an extra pair of square brackets around escaped shortcodes so that this early run of do_shortcode() doesn't end up affecting them.

Author: Viper007Bond

syntaxhighlighter.php

@@ -320,7 +320,39 @@ function output_shortcodes_for_tinymce() {
 	}
 
 
-	// A filter function that runs do_shortcode() but only with this plugin's shortcodes
+	/**
+	 * Process only this plugin's shortcodes.
+	 *
+	 * If we waited for the normal do_shortcode() call at priority 11,
+	 * then wpautop() and maybe others would mangle all of the code.
+	 *
+	 * So instead we hook in earlier with this function and process
+	 * just this plugins's shortcodes. To do this requires some trickery.
+	 *
+	 * First we need to clear out all existing shortcodes, then register
+	 * just this plugin's ones, process them, and then restore the original
+	 * list of shortcodes.
+	 *
+	 * To make matters more complicated, if someone has done [[code]foo[/code]]
+	 * in order to display the shortcode (not render it), then do_shortcode()
+	 * will strip the outside brackets and when do_shortcode() runs a second
+	 * time later on, it will render it.
+	 *
+	 * So instead before do_shortcode() runs for the first time, we add
+	 * even more brackets escaped shortcodes in order to result in
+	 * the shortcodes actually being displayed instead rendered.
+	 *
+	 * We only need to do this for this plugin's shortcodes however
+	 * as all other shortcodes such as [[gallery]] will be untouched
+	 * by this pass of do_shortcode.
+	 *
+	 * Phew!
+	 *
+	 * @param string $content The post content.
+	 * @param string $callback The callback function that should be used for add_shortcode()
+	 *
+	 * @return string The filtered content, with this plugin's shortcodes parsed.
+	 */
 	function shortcode_hack( $content, $callback ) {
 		global $shortcode_tags;
 
@@ -333,6 +365,13 @@ function shortcode_hack( $content, $callback ) {
 			add_shortcode( $shortcode, $callback );
 		}
 
+		// Extra escape escaped shortcodes because do_shortcode() is going to strip a pair of square brackets when it runs
+		$content = preg_replace_callback(
+			'/' . get_shortcode_regex( $this->shortcodes ) . '/',
+			array( $this, 'shortcode_hack_extra_escape_escaped_shortcodes' ),
+			$content
+		);
+
 		// Do the shortcodes (only this plugins's are registered)
 		$content = do_shortcode( $content, true );
 
@@ -343,6 +382,23 @@ function shortcode_hack( $content, $callback ) {
 	}
 
 
+	/**
+	 * Add extra square brackets around escaped shortcodes.
+	 * This is to counteract the beginning of the do_shortcode_tag() function.
+	 *
+	 * @param array $match The array of matches generated by get_shortcode_regex()
+	 *
+	 * @return string What should be placed into the post content. In this case it's the raw match, or an extra-wrapped raw match.
+	 */
+	function shortcode_hack_extra_escape_escaped_shortcodes( $match ) {
+		if ( $match[1] == '[' && $match[6] == ']' ) {
+			return '[' . $match[0] . ']';
+		}
+
+		return $match[0];
+	}
+
+
 	// The main filter for the post contents. The regular shortcode filter can't be used as it's post-wpautop().
 	function parse_shortcodes( $content ) {
 		return $this->shortcode_hack( $content, array( $this, 'shortcode_callback' ) );