Wordpress shortcode_unautop

function 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 ) ) );

    $pattern =
          '/'
        . '<p>'                              // Opening paragraph
        . '\\s*+'                            // Optional leading whitespace
        . '('                                // 1: The shortcode
        .     '\\['                          // Opening bracket
        .     "($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
        .     ')*?'
        .     '(?:'
        .         '\\/\\]'                   // Self closing tag and closing bracket
        .     '|'
        .         '\\]'                      // Closing bracket
        .         '(?:'                      // Unroll the loop: Optionally, anything between the opening and closing shortcode tags
        .             '[^\\[]*+'             // Not an opening bracket
        .             '(?:'
        .                 '\\[(?!\\/\\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';
    //this compiles the regex <p>\s*+(\[(shortcode1|shorcode2|etc)(?![\w-])[^\]\/]*(?:\/(?!\])[^\]\/]*)*?(?:\/\]|\](?:[^\[]*+(?:\[(?!\/\2\])[^\[]*+)*+\[\/\2\])?))\s*+<\/p>
    return preg_replace( $pattern, '$1', $pee );
}