Re: Applying .gitattributes text/eol changes

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 13, 2011, 23:30 UTC
Message-ID: <7vd3o01iw9.fsf@alter.siamese.dyndns.org>
In-Reply-To: <4D2F12EE.4020400@syntevo.com>

Marc Strapetz <marc.strapetz@syntevo.com> writes:

> So your suggestion is to fix "git update-index --really-refresh", so

The option is about telling git: "Earlier I promised I wouldn't touch these paths by setting their assume-unchanged bit, but I touched them. Please refresh the cached stat information in the index, ignoring the promise I didn't keep."

I do not think it is a good idea to conflate your "Everything is suspect because smudge filter has changed; please recompute all" request into the same option. People who use assume-unchanged would probably want "Please rescan because I changed smudge filter" request to be carried out while still honoring the assume-unchanged bit they set earlier.

> Anyway, I'm still wondering if it will resolve the "git reset --hard"
> problem of re-checking out every file, even if content is already
> identical in the working tree. I think that part has to be fixed, too.

There is not much to fix there. If you removed the index, then there is no information to tell you that "content is already identical" unless you actually check things out and compare. By the time you found it out, you already have done the checkout.

IOW, the current code does:

	open object
        read from the object
        deflate and write to the destination file

while your "fix" needs to look like this:

	open object
        read from the object
        deflate and write to a temporary file
        open the existing file
        read from the file and compare it to the temporary we just wrote
        if same, delete, otherwise rename the temporary file.

just for the rare case where there is an untracked file that the user is willing to overwrite (we are discussing "rm .git/index && reset --hard" here) happens to have the same contents. Not a good enough reason to add unwelcome complexity to the codepath.

> What do you think about "git checkout --fix-eols" option as an
> alternative? Its uses cases are more limited, though.

What does it do? "git checkout --fix-eols $path" will overwrite $path with the data at $path in the index? Perhaps you can use the "-f" option.

Adding an option to "checkout" might be better than update-index from the UI point of view, but the issue is not just "eols". "eol" is a mere special case of smudge filter that controls how the contents from the repository are modified before getting written out to the working tree.