Escaping quotes in [size] and [notag] tags

[size=20]I'm happy[/size]

gives

I\'m happy

[notag][size=20]I'm happy[/size][/notag] gives

[size=20]I\'m happy[/size]

both use function calls in the array. I removed the size check for now and it works:

//        '#\[size=(\d+)(?::\w+)?\](.*?)\[/size(?::\w+)?\]#sie'    => '_bbcode_size_tag(\\1, "\\2")',
          '#\[size=(\d+)(?::\w+)?\](.*?)\[/size(?::\w+)?\]#si'    => '<span style="font-size:\\1px">\\2</span>',