when you get an 80s film on dvd, how can you be sure you are getting the full unedited film as it was originally shown back then

I saw it opening weekend when it came out in the early 80's, I was 12 at the time, it was a fun movie the furst time I saw it, and it's fun when I watch it now, it's a film that never gets old. I downloaded the original theatrical version, as far as I know because it is a clean movie, it never needed editing for television, so you should have the full movie.