How to un-wrap code pasted into Emacs From StackOverflow

When I copy code from Stackoverflow and paste it into my emacs window, it pastes the whole thing as one super-long line, losing all the line-breaks. W开发者_StackOverflowhat's the easiest way to un-wrap this so I get back the line-breaks? Or paste it differently into emacs so it preserves line-breaks?

[EDIT: I read this question too quickly --- the approach I outlined will help clean up a lot of things, but not OP's actual problem. FWIW, I can't reproduce on the only windows box I have here]