Re: [PATCH] logging branch deletion to help recovering from mistakes

[Jonathan Nieder <jrnieder@gmail.com>]

Junio C Hamano wrote:

> "git log -g HEAD"
> keeps track of what was at the tip of HEAD, be it pointing at a branch or
> pointing diretly at a commit in a detached state, no?

Yes.

1. Imagine I have an interesting branch and delete it:

	$ git branch interesting $(lots of hard work)
	$ git branch -D interesting

Oops.  If I want to recover that branch, I may have a lot of digging
to do in the HEAD reflog.  It may not be there are all.  Your patch
mitigates that by allowing a simple "I didn't mean that" command.

	$ git branch --undelete interesting

2. Great.  Another way to lose a line of development, as Casey
mentioned, is to not give it a branch name in the first place:

	$ git checkout HEAD^0
	...
	$ git checkout something-else

Oops.  Well, not so bad.  If I want to recover my old work, I can
simply use

	$ git checkout HEAD@{1}

3. Now suppose I was not paying attention and made the mistake
from (1) or (2) a week ago and didn't realize it.  Now I want to
get back that code.

If it was situation (1), I can remember the name of the branch
and do

	$ git branch --undelete interesting

No problem [1].  If it was situation (2), I need to dig through the
HEAD reflog.  As Jeff explained, it is possible to script something up
to help organize the search.  I think Casey was suggesting doing that
work at HEAD-reattachment time instead, so you could do

	$ git branch --undelete-detached-head=old-head

to recover the last line of development made without a branch;
my response was that if this ends up frequently being useful
then I suspect something is wrong with the workflow.

Hoping that is clearer,
Jonathan

[1] as long as the branch name was not reused