If you're using an addon that spams (or intelligently refollows) autofollow then you may have run into the same problem as me where your character gets stuck Autorunning (not autofollowing) when you try to interrupt the motion and begin to use a spell with casting time. Obviously you can using a left or right turn button to break autofollow and you can use the autorun command.

What I need is a command that can be spammed that will break an autorun (much like a left or right turn breaks autofollow) and not interrupt casting ie not cause motion.

Note: The process of getting stuck in autorun does not involve accidentally hitting the autorun button (it is unbound). I believe autorun is a partial component to both autofollow and autointeract both which apparently can be deactivated partially (and improperly) resulting in the autorun component being left on and your guys wandering off into oblivion.