system/sef plugin background image parser regexp bug

[nextend]

Bug

The problem is that I'm using images in the style attributes for background images and I'm set the image urls with a full url:

<div style="background-image: url(&#039;http://test.org/test.png&#039;)"></div>

Note that the ' in the url() are properly encoded for HTML attributes. This is when the issue comes, the following regexp only match the not encoded ' and " characters and not the encoded ones. The regexp should be fixed by adding
' => '
" => "

The regexp is in plugins/system/sef/sef.php which used to find image urls in style attributes to fix them to the current site's relative path:

$regex = '#style\s_=\s_'":\s_url\s_(['"]?(?!/|' . $protocols . '|#)([^)\'\"]+)['"]?)#m';

Test:

<div style="background-image: url(&#039;http://test.org/test.png&#039;)"></div>

Result:

<div style="background-image: url("/my/site/path/&#039;http://test.org/test.png&#039;")"></div>

Desired result: - (Regexp do not match this url.)

<div style="background-image: url(&#039;http://test.org/test.png&#039;)"></div>

[ggppdk]

The regular expression has some negative look ahead to avoid matching things like:
url( '/
url( 'http://

we could add & # 039; to the negative lookahead:

Replacing:

// Background image.
$regex  = '#style\s*=\s*[\'\"](.*):\s*url\s*\([\'\"]?(?!/|' . $protocols . '|\#)([^\)\'\"]+)[\'\"]?\)#m';

with:

// Background image.
$regex  = '#style\s*=\s*[\'\"](.*):\s*url\s*\([\'\"]?(?!/|\&\#039;|' . $protocols . '|\#)([^\)\'\"]+)[\'\"]?\)#m';

[nextend]

For us the solution was to use uppercase URL in our HTML, as the SEF preg_match do not ignore case :)

Also I have one other use case when the regexp fails. Nowadays protocol relative urls are popular, so this would be perfect if you have a site with http and https too:

But the regular expression is not able to match the protocol so it fails and adds the previously mentioned path to the url.

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_{This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/7267.}

[brianteeman]

Closed as we have a PR for testing #11412

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_{This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/7267.}