From: Junio C Hamano <junkio@cox.net>
Date: Wed, 04 May 2005 17:37:40 GMT
Subject: Re: Howto update a 'dirty' entry in the cache from the object database
Message-ID: <7vll6uopsr.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <Pine.LNX.4.58.0505041014510.2328@ppc970.osdl.org>

>>>>> "LT" == Linus Torvalds <torvalds@osdl.org> writes:

LT> On Wed, 4 May 2005, Thomas Glanzmann wrote:
>> 
>> I edited a bunch of files and notice that I want to revert back one of
>> the files to the original one (the one that comes with HEAD). But I
>> already updated the cache. Is there a way to 'patch' the cache with the
>> original file.

LT> Absolutely.

LT> You can do it several ways. The easiest one is

LT> 	git-read-tree -m HEAD
LT> 	git-checkout-cache -f filename

LT> but this means that you revert your entire index file to the old HEAD 
LT> information, so you'll need to do git-update-cache on the files that you 
LT> changed.

I think the easiest one that does not lose the cache for other
files is:

    git-diff-cache -z HEAD |
    GIT_EXTERNAL_DIFF=git-apply-patch-script \
        git-diff-tree-helper -z -R filename

This means: find diff from HEAD to the cache, and apply the diff
in the reverse, only to the filename.