Re: cogito - how to drop a commit

From: Linus Torvalds <torvalds@osdl.org>
Date: Aug 7, 2005, 00:42 UTC
Message-ID: <Pine.LNX.4.58.0508061727000.3258@g5.osdl.org>
In-Reply-To: <20050806223436.GA6495@mars.ravnborg.org>

On Sun, 7 Aug 2005, Sam Ravnborg wrote:

Show 5 quoted lines

>
> I accidently commited too many files to my tree today, and now I want to
> drop the commit so I have logically separate commits.
> 
> What is the right way to do this - in cogito hopefully.

Not cogito, and this needs to be scripted, but if what you _want_ to do is undo the commit (in order to re-do it as several commits), here are the raw git commands necessary (you could make this "git-fix-script", and then "git fix" basically does the git equivalent of what "bk fix -C" did)

	# Set up
	#
	. git-sh-setup-script || die "Not a git archive"

	# Figure out the parent.
	#
	parent=$(git-rev-parse --verify HEAD^) || exit

	#
	# Update the index to be at that point in time and make HEAD 
	# point to it, but don't update the working tree contents (ie
	# the changes remain in the working tree, to be re-committed).
	#
	git-read-tree -f -m $parent && echo $parent > .git/HEAD

NOTE! The commit still _exists_, but the HEAD reference to it is now lost. If you want to save that as a broken branch, you can precede this with

	git branch broken-branch

which means that the broken point got saved off as "broken-branch".

And if you didn't do that (or if you _did_ do that, and later end up deciding to throw that branch away with a

	rm .git/refs/heads/broken-branch

or similar) then you can get rid of the stale and unreachable objects with a simple "git prune".

Be careful! "git prune" _will_ throw away all the objects that it can't find references to. You might want to run "git-fsck-cache --full --unreachable" first to get an idea of what it's going to throw away.

			Linus