Re: Amending commits

[Dmitry Gutov]

On 25.09.2022 23:15, Gregory Heytings wrote:
> > > > As someone who does not really understand Git, does this mean we are 
> > > > rewriting the log message without also committing a change?  I 
> > > > thought that was not allowed by Git.
> > >
> > > git commit --amend is mainly used to change a commit before pushing 
> > > it. Rewriting history (i.e. changing an already public commit) is (by 
> > > default) not possible.
> >
> > When people say that in Git you cannot rewrite history, what it means 
> > is that you can't change anything about a given *commit id* (aka 
> > "revision").
>
> Hmm... no, AFAIU, it means that (by default) you cannot replace the 
> commit history of a public repository with commits which do not have the 
> HEAD of the public repository as their parent.  E.g. if your public 
> repository is
>
> A - B - C - D
>              ^ HEAD
>
> you cannot change it into
>
>      B - C - D
>    /
> A - E - F - G
>              ^ HEAD

You can even do that (if 'force pushes' are not disabled in the 
repository's settings).

It's just usually a bad idea.

So you can rewrite history, but commits are "immutable".