Ticket #14050: plugin.php

<?php
/*
Plugin Name: WordPress Bug #14050 Hotfix
Plugin URI: http://core.trac.wordpress.org/ticket/14050
Description: Improves the big monster shortcode_unautop() regular expression, which is causing all the ruckus
Author: Leho Kraav
Author URI: http://leho.kraav.com
Version: 1.0
*/

if ( is_admin() ) return;

/**
 * Don't auto-p wrap shortcodes that stand alone
 *
 * Ensures that shortcodes are not wrapped in <<p>>...<</p>>.
 *
 * @since 2.9.0
 *
 * @param string $pee The content.
 * @return string The filtered content.
 */
function wp14050_shortcode_unautop( $pee ) {
    global $shortcode_tags;

    if ( empty( $shortcode_tags ) || !is_array( $shortcode_tags ) ) {
        return $pee;
    }

    $tagregexp = join( '|', array_map( 'preg_quote', array_keys( $shortcode_tags ) ) );

    $pattern =
          '/'
        . '<p>'                              // Opening paragraph
        . '\\s*+'                            // Optional leading whitespace
        . '('                                // 1: The shortcode
        .     '\\[\\/?'                      // Opening bracket for opening or closing shortcode tag
        .     "($tagregexp)"                 // 2: Shortcode name
        .     '(?![\\w-])'                   // Not followed by word character or hyphen
                                             // 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
        .     ')*?'
        .     '[\\w\\s="\']*'                // Shortcode attributes
        .     '(?:'
        .         '\\s*+'                    // Optional leading whitespace, supports [footag /]
        .         '\\/\\]'                   // Self closing tag and closing bracket
        .     '|'
        .         '\\]'                      // Closing bracket
        .         '(?:'                      // Unroll the loop: Optionally, anything between the opening and closing shortcode tags
        .             '(?!<\/p>)'            // Not followed by closing paragraph
        .             '[^\\[]*+'             // Not an opening bracket, matches all content between closing bracket and closing shortcode tag
        .             '(?:'
        .                 '\\[(?!\\/\\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 );
}

# wp-includes/default-filters.php
foreach ( array( "term_description" ) as $filter ) {
    remove_filter( $filter, "shortcode_unautop" );
    add_filter( $filter, "wp14050_shortcode_unautop" );
}

remove_filter( "the_content", "shortcode_unautop" );
add_filter( "the_content", "wp14050_shortcode_unautop" );

remove_filter( "the_excerpt", "shortcode_unautop" );
add_filter( "the_excerpt", "wp14050_shortcode_unautop" );