Unity-Technologies/VersionControlPlugins — pull request #14 by SeriousLabs (2014-08-20 16:57:57+00:00)
Title: Perforce Checkout Sync Check

Adds in a check to make sure files are in sync with the repository before checking them out from Perforce. Otherwise, users can check out an asset in Unity that is out of sync locally with the repository. This then makes them lose work later when they go to submit only to find that the asset they checked out was actually out of sync, cause the current behavior of the plugin does not have this safety check in it.