Trying to make a text editor as a part of a game.

[Syerjchep]

This is the code I got, which works, but crashes randomly:
http://pastebin.com/yyvUSaTQ
(sorry about the external link, it was too big to paste here)

So yeah, I was basically wondering if anyone could spot any obvious problems or suggest a completly new way of making a text editor in a program. (that uses SDL)