An unexpected second version of the Mozilla Firefox 4 release candidate was issued on Friday to correct minor security issues.
Mozilla had previously said it expected the first release candidate (RC) to be the final version of the Firefox 4 web browser. It is currently scheduled for general release on Tuesday.
However, the company issued the update to implement "two very small, very isolated fixes in order to better protect Firefox 4 users", according to a forum post from Mike Beltzner, director of Firefox, on Thursday.
According to the Firefox 4 RC2 release notes posted on Friday, changes to the browser included blacklisting "a few" invalid HTTPS certificates, updating localisations for 29 languages and adding support for Vietnamese. The security fixes were also included in an update to Firefox 4 RC1 for Android.
Despite issuing the last minute release candidate, Beltzner said that he still expects the launch on Tuesday to go ahead.
"There is no change required to our schedule. We still expect to release the final version of Firefox 4 for Windows, OSX and Linux on 22 March as planned," he wrote.