Upgrading for free Apple trialware from third party distributors? I upgraded to Maverics, then I read than older trialware of iWork, Aperture and possible FCP and Logic Pro are being upgraded for free to their latest versions by Apple on the App Store desktop application. All trial versions with the exception of FCP were removed from the Apple's site, but third party distributors could have those older versions still available for download.

The word free add some negative connotation to the question, like if one could be trying to steal software from Apple, but if the price tag were someting diferent from FREE, I think there would not be any problem upgrading Apple software downloaded from third party software distributors. 

Would there be any legal issues installing and upgrading that trialware to the full free version in that way?
As MacTrast discovered, it's not a bug, Apple is intentionally upgrading older Aperture, iWork and iLife versions (paid, trial, pirated or otherwise). 


  [However,] it’s no coincidence that Apple’s support site doesn’t have downloads for the new Aperture, iWork, and iLife updates. They aren’t in our Software Update system either – and there’s a good reason for that. With Mavericks, we have changed the way we distribute updates for legacy versions of our apps


So "legally", downloading the trials from another site just to get the free upgrade is still pirating software you're not entitled to. Apple is just taking the stance that:


  We like to believe that our users are honest, even if that belief is in vain.


Also, the Aperture trail page does specifically state that you need to uninstall the trial before purchasing it from the Mac App Store.