Re: Questions about the new

On Mon, Oct 12, 2009 at 02:19:11PM +0200, Johannes Sixt wrote:

With grafts you can only change parenthood; with replace entries you can
change parenthood *and* all other aspects of a commit (message, author,
committer, dates).

Actually, you can. I have written a script that did exactly this. It
required to modify parents to point to the new commit. The tricky part
was that modification could be on top of other modifications, but I was
able to handle this case too. Yet, my script was so hackish that I have
never dared to share it with someone (and I used it only couple times
during CVS to Git conversion).

Hence, replace entries are more general than grafts.

I think both mechanism are theoretically equivalent, but with grafts,
it was rather difficult to replace objects (but not impossible!).

The problem with grafts was that, for example, git-pack-objects obeyed the
graft, and could create a broken repository by removing grafted-away
objects. And since git-fsck also obeyed the graft, it did not notice the
breakage.

Moreover, grafted-away objects could be removed by the garbage collector...


Dmitry