Re: Moving to git

On Sat, 2011-10-08 at 01:15 -0700, Maciek Sakrejda wrote:
> Verified that this works, and that the (filtered) diffs are clean for
> all tags. I've incorporated the script changes and pushed them out to
> the github repository I sent out earlier. I don't quite get the
> filtering expression here--can someone clarify?
>
> diff -r --exclude=CVS --exclude=.git . ../cvs-co/${tag} \
> | grep "\$Header:" -v \
> | egrep -v "^\-\-\-$" \
> | egrep -v "^[0-9]+c[0-9]+" \
> | grep -v "^diff \-r '\-\-exclude"
>
> Is this just filtering out the '$Header' in the Makefile from back in
> the day? Is there a better way to deal with this? It seems to get
> expanded to include my username and path to export.

I guess so. I just choose to ignore it, as it seemed autogenerated and
comments.

> I'm fairly certain that with a judicious application of git
> filter-branch, I can strip out all those "manufactured commits" that
> Tom mentioned. The issues Kris mentioned [1] seem to be more complex,
> but I don't quite understand what they are. Can someone point out a
> specific bit of history that's mangled in Marko's github repo? I
> *think* it might be something like the problems discussed starting
> here [2] for the server migration, but it'd be helpful to see this
> going wrong in the jdbc history.
>
> Also, from reading the mailing list archives, it looks like tag-by-tag
> verification may *not* be a good way to verify sanity of full history.
> Any suggestions as to what a more extensive automated verification
> method might entail? We'd want to do manual spot-checks as well, of
> course, but is there something more we can do for an automated check?
>
> [1]: http://archives.postgresql.org/pgsql-www/2008-12/msg00124.php
> [2]: http://archives.postgresql.org/pgsql-hackers/2010-08/msg01274.php

After reading [2] and similar documentation about cvs, I come to a
conclusion in two parts.

a) Because CVS tags single files instead of a branch, it is impossible
to convert them to true git tags. I consider this bad design in CVS.

b) Because of this design flaw, I suggest we move to git ASAP.

PS: Does it really matter if the history is a bit altered by the
conversion process? As long as HEAD and the tags are the same?
The history could be kept in a read-only cvs-repository :-)

Mvh

Kny