[lacedeconstruct]

Life is simple until we play with time, once you start altering the past everything falls apart

[knighthack]

This... seems a bit deeper than a comment about just Git.

[Zambyte]

It's not possible to alter commits with git. They are immutable. You can only make new commits that are based on existing ones in some way. The distinction is important, because the original commit (such as a commit pre-rebase) still exists after it's been "changed".

[jcranmer]

> The distinction is important, because the original commit (such as a commit pre-rebase) still exists after it's been "changed".

The original commit will only exist for as long as git deigns not to garbage collect it.