auto-save when loading new file

[arjunguha]

It is possible for the buffer to become dirty when a new file is selected, but not yet loaded. These updates may be clobbered in a 1 second window. Simple solution is to lock the buffer when a file is being fixing.

[arjunguha]

I think this is now addressed?

[sp1tz]

It's less than a second, but still possible with deliberate intent to type nonsense exceedingly fast. Could be dependent on users' Internet connection though.