#12 Images in CSS url() not changed.

Some images (such as background images) are defined in
stylesheets and are not filtered out. Here is the new
filter function that fixes this problem:

function modify_urls()
{
preg_match_all("#\s(href|src|action|codebase|url)
=([\"\'])?(.*?)([\"\'])?([\s\>])#i", $this->response_body,
$matches, PREG_SET_ORDER);

foreach ($matches as $match)
{
$uri = trim($match[3]);
$fragment = ($hash_pos = strpos($uri, '#') !==
false) ? '#' . substr($uri, $hash_pos) : '';

if (!preg_match('#^[\w+.-]+://#i', $uri))
{
switch (substr($uri, 0, 1))
{
case '/':
$uri = $this->url_segments
['scheme'] . '://' . $this->url_segments['host'] . $uri;
break;
case '?':
$uri = $this->url_segments
['base'] . '/' . $this->url_segments['file'] . $uri;
break;
case '#':
continue 2;
break;
case 'm':
if (substr($uri, 0, 7) == 'mailto:')
{
continue 2;
}
default:
$uri = $this->url_segments
['base'] . '/' . $uri;
break;
}
}

$uri = $this->encode_url($uri);
$replace = ' ' . $match[1] . '=' . $match[2] .
$this->script_url . '?url=' . $uri . $fragment . $match[4] .
$match[5];

$this->response_body = str_replace($match[0],
$replace, $this->response_body);
}

preg_match_all("#(url[(])(.*?)([)])#i", $this-
>response_body, $matches, PREG_SET_ORDER);
foreach ($matches as $match)
{
$uri = trim($match[2]);
$fragment = ($hash_pos = strpos($uri, '#') !==
false) ? '#' . substr($uri, $hash_pos) : '';

if (!preg_match('#^[\w+.-]+://#i', $uri))
{
switch (substr($uri, 0, 1))
{
case '/':
$uri = $this->url_segments
['scheme'] . '://' . $this->url_segments['host'] . $uri;
break;
case '?':
$uri = $this->url_segments
['base'] . '/' . $this->url_segments['file'] . $uri;
break;
case '#':
continue 2;
break;
case 'm':
if (substr($uri, 0, 7) == 'mailto:')
{
continue 2;
}
default:
$uri = $this->url_segments
['base'] . '/' . $uri;
break;
}
}

$uri = $this->encode_url($uri);
$replace = $match[1] . $this->script_url . '?
url=' . $uri . $fragment . $match[3];

$this->response_body = str_replace($match[0],
$replace, $this->response_body);
}

}