How to Integrate Trac and WordPress (as done on the WP Development blog)?

Back in May, I recall seeing a post on the WordPress Development blog by Alex M (Viper007bond.com) where he added functionality for Automatic Ticket/Revision/Diff Linking which allows for linking to Trac tickets, Trac revisions, and Trac diff comparisons.

I am wanting to do the same thing with an internal WordPress blog and Trac that I have for my business. I haven’t seen where this was released as a WordPress plugin so I was hoping that people could point me in the right direction on how to do this in how to do this integration between Trac and WordPress. Thanks.

Here’s the source of the functionality. It’s just a content filter and some basic regex that one of my coworkers at Automattic wrote.

add_filter( 'the_content', 'markup_wporg_links' );
add_filter( 'comment_text', 'markup_wporg_links' );

function markup_wporg_links( $content ) {
    $find = array(
        '/(\ |^)#(\d{3,6})(\b|$)/i', // core trac ticket #1234-core in http://core.trac.wordpress.org/ticket/
        '/(\ |^)r(\d{3,6})(\b|$)/i', // core changeset r1234-core in http://core.trac.wordpress.org/changeset/1234
        '/(\ |^)diff:@(\d{3,6}):(\d{3,6})(\b|$)/i', // core diff diff-core:@20:30 https://core.trac.wordpress.org/changeset?new=30&old=20
    );

    $replace = array(
        '<a href="http://core.trac.wordpress.org/ticket/$2">$0</a>', // core trac ticket
        '<a href="http://core.trac.wordpress.org/changeset/$2">$0</a>', // core trac changeset
        '<a href="http://core.trac.wordpress.org/changeset?new=$3&old=$2">$0</a>', // core diff
    );

    preg_match_all( '#[^>]+(?=<[^/]*[^a])|[^>]+$#', $content, $matches, PREG_SET_ORDER );

    foreach ( $matches as $val )
        $content = str_replace( $val[0], preg_replace( $find, $replace, $val[0] ), $content );

    return $content;
}

Modify it to suit your needs.