Wikimedia Bugzilla is closed!

I am trying to prevent untrusted users from adding external links to pages on my wiki. I have created the filter with these conditions:

(length(added_links) > 0) & !('trusted_user' in user_groups)

and it matches all old edits that I would like to block. During testing it also blocks adding new links to existing pages.

But it fails to block creation of a new page containing external links (hit count is not increased). Maybe I am doing something wrong. I have tried the (length(added_links) > 0) alone, and it is the same. I also tried (length(all_links) > 0) with the same result: new users still can create pages containing external links. In the 'examination' all the filter condition versions perfectly match the modifications they should have blocked. 

I have also tried (new_size > 0) and this one works fine (new page creations are blocked).

I have these settings for Emergency Disable feature (effectively turning it off, hopefully):
$wgAbuseFilterEmergencyDisableThreshold['default'] = 1;
$wgAbuseFilterEmergencyDisableCount['default']     = 100;
$wgAbuseFilterEmergencyDisableAge['default']       = 1;

I can provide an account to my wiki for someone to test it, if necessary. I had to disable creation of new users and anonymous editing because of spam.