Re: Newbie falls at first hurdle

From: Junio C Hamano <junkio@cox.net>
Date: Sep 18, 2005, 20:10 UTC
Message-ID: <7vfys22l3k.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <200509182011.10689.alan@chandlerfamily.org.uk>

Alan Chandler <alan@chandlerfamily.org.uk> writes:

Show 7 quoted lines

> I effectively loaded both my current code and the day before's
> backup into git as two separate branches.
>
> What I was then trying to do, via various attempts with git diff -p was to 
> extract small chunks of updates (ie limit scope over a few files).  Edit the 
> result to limit the diff to cover a small update and then apply it to a my 
> current stuff to slowly undo some of the mess that I had made.

Ah, what you have to work with are only date-based snapshots of various states (i.e. the separation between one snapshot and another does not necessarily have much to do with a single set of logically isolated changes).

I end up doing that myself, although the situation I'd be in tend to be one logical change spread over multiple commits (the other way around from your case where one diff contains many logically unrelated chagnes). I run git-diff-tree -p between states to obtain a set of N diffs, look them over and hand edit them to collect related things together and separate independent things separate to create a different set of M diffs. then create a temporary branch that is reset to the state before those N diffs and use applymbox to apply M diffs. This is essentially what Martin suggested.

In your case, each diff you have contains unrelated changes and you have to move things around. It's a pain but I am afraid there are not any SCM can do much to help you.