Re: How to determine buffer change

[Thorsten Jolitz <tjolitz@gmail.com>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>> 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?

> set buffer-undo-list to nil (after all, so you really want the user to
> be able to un-insert the initial text?).

No, I don't, and the simplest solutions are often the best but don't
come to ones mind first. That works like a charm, thanks. 

-- 
cheers,
Thorsten