mozilla/browserid — pull request #1385 by floatingatoll (2012-04-04 07:00:12+00:00)
Title: use VALUES(col) instead of passing the col value twice, per 5.0+ syntax

http://dev.mysql.com/doc/refman/5.1/en/insert-on-duplicate.html

"VALUES(col_name) in the ON DUPLICATE KEY UPDATE clause refers to the value of col_name that would be inserted, had no duplicate-key conflict occurred"