From d9cd72430fe5ee46ed4ecef10f083543eec33d92 Mon Sep 17 00:00:00 2001
From: Andrew Nacin <wp@andrewnacin.com>
Date: Thu, 20 Nov 2014 14:30:37 +0000
Subject: [PATCH] Anchor texturize to shortcodes to improve regex efficiency.

For the 4.0 branch; see [30449] for trunk.

props miqrogroove.
see #29557 for segfault issues.

Built from https://develop.svn.wordpress.org/branches/4.0@30450


git-svn-id: http://core.svn.wordpress.org/branches/4.0@30444 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/formatting.php | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index 1f18ab9d91..e79043bccc 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -28,7 +28,7 @@
  * @return string The string replaced with html entities
  */
 function wptexturize($text, $reset = false) {
-	global $wp_cockneyreplace;
+	global $wp_cockneyreplace, $shortcode_tags;
 	static $static_characters, $static_replacements, $dynamic_characters, $dynamic_replacements,
 		$default_no_texturize_tags, $default_no_texturize_shortcodes, $run_texturize = true;
 
@@ -205,21 +205,34 @@ function wptexturize($text, $reset = false) {
 
 	// Look for shortcodes and HTML elements.
 
+	$tagnames = array_keys( $shortcode_tags );
+	$tagregexp = join( '|', array_map( 'preg_quote', $tagnames ) );
+	$tagregexp = "(?:$tagregexp)(?![\\w-])"; // Excerpt of 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.
+
 	$regex =  '/('			// Capture the entire match.
 		.	'<'		// Find start of element.
 		.	'(?(?=!--)'	// Is this a comment?
-		.		'.+?--\s*>'	// Find end of comment
+		.		$comment_regex	// Find end of comment
 		.	'|'
 		.		'[^>]+>'	// Find end of element
 		.	')'
 		. '|'
 		.	'\['		// Find start of shortcode.
-		.	'\[?'		// Shortcodes may begin with [[
+		.	'[\/\[]?'	// Shortcodes may begin with [/ or [[
+		.	$tagregexp	// Only match registered shortcodes, because performance.
 		.	'(?:'
-		.		'[^\[\]<>]'	// Shortcodes do not contain other shortcodes.
+		.		'[^\[\]<>]+'	// Shortcodes do not contain other shortcodes. Quantifier critical.
 		.	'|'
-		.		'<[^>]+>' 	// HTML elements permitted. Prevents matching ] before >.
-		.	')++'
+		.		'<[^\[\]>]*>' 	// HTML elements permitted. Prevents matching ] before >.
+		.	')*+'		// Possessive critical.
 		.	'\]'		// Find end of shortcode.
 		.	'\]?'		// Shortcodes may end with ]]
 		. ')/s';
@@ -241,12 +254,12 @@ function wptexturize($text, $reset = false) {
 
 			continue;
 
-		} elseif ( '[' === $first && 1 === preg_match( '/^\[(?:[^\[\]<>]|<[^>]+>)++\]$/', $curl ) ) {
+		} elseif ( '[' === $first && 1 === preg_match( '/^\[\/?' . $tagregexp . '(?:[^\[\]<>]+|<[^\[\]>]*>)*+\]$/', $curl ) ) {
 			// This is a shortcode delimiter.
 
 			_wptexturize_pushpop_element( $curl, $no_texturize_shortcodes_stack, $no_texturize_shortcodes );
 
-		} elseif ( '[' === $first && 1 === preg_match( '/^\[\[?(?:[^\[\]<>]|<[^>]+>)++\]\]?$/', $curl ) ) {
+		} elseif ( '[' === $first && 1 === preg_match( '/^\[[\/\[]?' . $tagregexp . '(?:[^\[\]<>]+|<[^\[\]>]*>)*+\]\]?$/', $curl ) ) {
 			// This is an escaped shortcode delimiter.
 
 			// Do not texturize.