* Debug message emitted by wfDebugLog() will now be prefixed with the group
name when its logged to the default log file. That is the case whenever the
group has no key in wgDebugLogGroups, that will help triage the default log.
+* (bug 24620) Add types to LogFormatter
=== Bug fixes in 1.21 ===
* (bug 40353) SpecialDoubleRedirect should support interwiki redirects.