Subject: bug#4587: Antwort: Re: bug#4587: 23.1; sort-lines and sort-fields always set buffer modified

From: Stefan Monnier <[email-masked]>
Date: Wed, 30 Sep 2009 09:51:50 -0400

>> Yes, that's generally desirable.  But in the above cases, given the way
>> the code currently works, it's fairly inconvenient to do (the code does
>> modify the buffer, it just so happens that the end text is the same as
>> the original text), so it doesn't seem worth the trouble.

> Wouldn't it be possible in case of an unmodified buffer to copy the
> content of the region at the beginning to a temporary buffer, compare it
> to the result afterwards, and if they match to restore the unmodified
> status?

I'd indeed expect that to implement the feature you request, the code
would have to do something like that.  Most likely not copying the text
itself, but instead storing an md5 or somesuch hash of the text.

> I sometimes need to check a list (which isn't small enough to be checked
> at a glance) after editing it if it is still sorted.
> Now I write he region before and after sorting it to separate files and
> compare them, but I wonder if a powerful tool like Emacs must keep such an
> obvious annoyance like this...

No, it definitely doesn't have to keep such obvious annoyances.
But it's not very high on the priority list.

        Stefan