Behavior of "exit"

[Stephan Pfab <pfab thales sai mathematik uni-ulm de>]

Hi

What should "exit" do:

 1: Exit the program and possibly loose all work

 No

 2: Ask the user whether he wants any changes to be saved
    and exit then

 Used a lot, but ...

 3: Save all changes in a special area, then exit. On a restart
    ask whether user wants to continue working with his last
    state or discard all unsaved work.
    (Note the quick safe should not overwrite the current file,
     so that discarding is still possible)

 Yess.

2 is really just there because most programmers are to lazy
to implement 3. 
3 follows the concept that the computer does what I tell him to do
(I said exit, not ask me questions) but recovers from any stupid
commands.

I really would like us go with 3.
How much extra work would this imply ?
Are there important applications which can not work this way ?

Stephan