From 0c8039be21478c340f7f483f775da20cc65b4525 Mon Sep 17 00:00:00 2001
From: Andrew Nacin <wp@andrewnacin.com>
Date: Thu, 20 Nov 2014 14:40:09 +0000
Subject: [PATCH] Anchor texturize to shortcodes to improve regex efficiency.

Merges [30452] to the 3.7 branch.

props miqrogroove.
see #29557 for segfault issues.

Built from https://develop.svn.wordpress.org/branches/3.7@30456


git-svn-id: http://core.svn.wordpress.org/branches/3.7@30447 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/formatting.php | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index 904c99b17b..17133ae09d 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -107,7 +107,14 @@ function wptexturize($text) {
 	$no_texturize_tags_stack = array();
 	$no_texturize_shortcodes_stack = array();
 
-	$textarr = preg_split('/(<.*>|\[.*\])/Us', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
+	// Look for shortcodes and HTML elements.
+	
+	$shortcode_regex =
+		  '\['          // Find start of shortcode.
+		. '[^\[\]<>]++' // Shortcodes do not contain other shortcodes. Possessive critical.
+		. '\]';         // Find end of shortcode.
+
+	$textarr = preg_split("/(<[^>]*>|$shortcode_regex)/s", $text, -1, PREG_SPLIT_DELIM_CAPTURE);
 
 	foreach ( $textarr as &$curl ) {
 		if ( empty( $curl ) )
@@ -117,7 +124,7 @@ function wptexturize($text) {
 		$first = $curl[0];
 		if ( '<' === $first ) {
 			_wptexturize_pushpop_element($curl, $no_texturize_tags_stack, $no_texturize_tags, '<', '>');
-		} elseif ( '[' === $first ) {
+		} elseif ( '[' === $first && 1 === preg_match( '/^' . $shortcode_regex . '$/', $curl ) ) {
 			_wptexturize_pushpop_element($curl, $no_texturize_shortcodes_stack, $no_texturize_shortcodes, '[', ']');
 		} elseif ( empty($no_texturize_shortcodes_stack) && empty($no_texturize_tags_stack) ) {
 			// This is not a tag, nor is the texturization disabled static strings
@@ -158,6 +165,8 @@ function _wptexturize_pushpop_element($text, &$stack, $disabled_elements, $openi
 
 			array_push($stack, $matches[1]);
 		}
+	} elseif ( 0 == count( $stack ) ) {
+		// Stack is empty. Just stop.
 	} else {
 		// Closing? Check $text+2 against disabled elements
 		$c = preg_quote($closing, '/');