mat <matthieu.stigler@xxxxxxxxx> writes:
> commits. But when looking on gitk, I see that
> git commit blabla --amend
>
> does create each and every time a new commit,
Yes. In Git, objects (including commits) are fundamentally immutable.
You never modify an object, you create a new one, and usually forget
about the old one.
> I mean: with git log,
> there is only one commit, but on gitk, I see many, with the same name
> but different revision ID....
The revision ID is the sha1sum of the commit content. So, if they have
different contents, they _must_ have different IDs.
What happens is that you start with a history like
A---B <- master
and then try to --amend B. What happens is that you create a new B,
say B', and let the branch you sit on point to this new one. Like:
A---B
\
`-B' <- master
Most of the time, B has just become unreachable: no branch contain it,
no tag point to it, ... so you actually see
A---B' <- master
and it very much looks like you just modified B.
Now, if you made B reachable before your commit --amend, like by
pushing it to another repo, letting someone else pull from it, or if B
is already part of another branch, then the situation is different.
For example, if B is already part of a branch, like this:
.---- temp-branch
v
A---B---C <- master
If you do a checkout of temp-branch, then commit --amend, you end up
in this situation :
A---B---C <- master
\
`-B' <- temp-branch
The solutions:
* If you already published your commit, then don't amend it. Period.
* If you want to rewrite an old commit in a branch, then read about
"git rebase -i", but make sure you read all the warnings about
rebase before you do so.
--
Matthieu Moy
http://www-verimag.imag.fr/~moy/
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html