Last modified: 2014-03-27 17:14:24 UTC
See zero.inc.vcl.erb. The Opera *User-Agent* should be the Opera Mini Proxy instead.
Change 92038 had a related patch set uploaded by Dr0ptp4kt: Verify User-Agent versus source proxy for X-CS=502-16. See bug 56119. https://gerrit.wikimedia.org/r/92038
A 2% sampling showed that the User-Agent alwasy contained "Opera", so the existing condition seems to be good enough. Nonetheless, once https://gerrit.wikimedia.org/r/#/c/88261 is approved, zero.inc.vcl.erb could be updated to look at X-Forwarded-By instead.
Identification is now based on source proxy and xff only, in addition to zero subdomain.