Re: Keeping reflogs on branch deletion

From: Jeff King <peff@peff.net>
Date: Feb 14, 2008, 15:17 UTC
Message-ID: <20080214151752.GB3889@coredump.intra.peff.net>
In-Reply-To: <alpine.LFD.1.00.0802140945520.2732@xanadu.home>

On Thu, Feb 14, 2008 at 10:00:58AM -0500, Nicolas Pitre wrote:

Show 6 quoted lines

> > When deleting a branch, is there any reason we can't add a deletion
> > entry into the reflog and keep the reflog around?  This would seem to be
> > a lot safer; I know I've been burned by expecting the reflog safety net
> > to be there, and surprised that it's not when I've deleted a branch.
> 
> No.  That would only accumulate dead reflog files in the repository.

How is that any different than accumulating old entries in reflog files for branches that _do_ exist? In both cases, they should be dealt with via time-based pruning.

> And as Junio said above, the "HEAD" reflog contains everything you moved 
> to, including detached heads, and of course branch heads that might now 
> be deleted.  You can easily retrieve a deleted branch head from there.

By that rationale, why do we bother keeping any reflog besides HEAD in the first place? I can think of two reasons:

  1. it's much more convenient to type branch@{1} than to sift through
     HEAD's reflog looking for checkout events and guessing which branch
     we were on
  2. it's possible to change a ref without it being on the HEAD, in
     which case the HEAD reflog doesn't contain the change.

In other words, I don't see "oops, I deleted this branch and its history is valuable to me" as significantly less likely than "oops, I got rid of this commit and its history is valuable to me."

-Peff