Re: How to determine buffer change

[Eli Zaretskii]

> From: Thorsten Jolitz <tjolitz@gmail.com>
> Date: Sat, 05 Apr 2014 13:41:41 +0200
> 
> in a program I insert text in an empty temporary edit-buffer, what of
> course modifies the `buffer-undo-list'.
> Assume that at this moment (lets call it time T1)
> 
> ,------------------------------
> | M-: (length buffer-undo-list)
> `------------------------------
> 
> returns 9. 
> 
> Now when there are changes to the text in the edit-buffer, these are
> copied to the original buffer after quitting. But when nothing has
> changed after the insertion of the original text, it would be better to
> simply discard the edit-buffer and not touch the original buffer at
> all. 
> 
> I could remember the length of the buffer-undo-list at time T1 and then
> check if it changed when quitting, but this does not seem very robust,
> since this length grows and shrinks in both directions.

Did you try using buffer-modified-tick?