Re: git fast-import : How to change parent during import?

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Mar 8, 2011, 22:23 UTC
Message-ID: <20110308222328.GE26471@elie>
In-Reply-To: <AANLkTini6NgeYxRdFtSDKe8GEEszDvXwRtLnuymiRNt4@mail.gmail.com>

Hi,

Vitor Antunes wrote:

> On Tue, Mar 8, 2011 at 2:44 AM, Jonathan Nieder <jrnieder@gmail.com> wrote:

Show 5 quoted lines

>> The advice in the section "Use Tag Fixup Branches" of git-fast-import(1)
>> might be useful.
>
> I'm still trying to understand it. Do you know of any practical
> example that I can look into?

It's likely I misunderstood what you're trying to do. If you have some work in progress, I'd be glad to look at it.

Anyway, concerning tag fixup branches: git://repo.or.cz/cvs2svn.git has an example in cvs2svn_lib/git_output_option.py::process_tag_commit. The idea is to make commits that don't belong to any branch on a separate TAG_FIXUP ref, using the "reset" command where appropriate; then the resulting commits can be inspected, merged, reset to, or used in some other way later.

The "tag fixup" idea is that in VCSes like CVS, tags do not necessarily match the content on any branch. So the history looks somewhat like so (time flowing left to right):

                     TAG
                    /
 o --- o --- o --- o --- o --- o ...

instead of the perhaps more sensible

 o --- o --- o --- TAG --- o --- o ...

The side branch leading up to a tag does not correspond to any branch name; after it is in the correct state one can use the "tag" command to get it remembered in permanent history. The same technique might be useful whenever you are creating history that is not meant to stay permanently on any branch.

Jonathan