Chris Torek <chris.torek@xxxxxxxxx> writes:
> On Mon, Dec 2, 2024 at 4:15 AM tao lv <thebookofunknowable@xxxxxxxxx> wrote:
>> I want to revert the code to a specific commit. ...
>
> OK, first some background:
>
> * A commit _is_ a full snapshot of every file, as of the state
> it had at the time you (or whoever) made that particular
> commit. Hence, if you want the particular files from a
> particular commit, you simply check out that (historical)
> commit.
>
> Now:
>
>> I don't want to revert each individual commit; I just want to restore
>> the code to this specific commit while retaining all the current
>> history commits.
>>
>> How can I achieve this? Is there a better way than using the revert function?
>
> git checkout [--detach] <hash> # or git switch --detach <hash>
> git reset --soft <branch-name>
>
> git restore --no-overlay -S -W <hash>
While that would _work_ in the sense that you can revert the effect
of what the discarded commits did, I would not recommend any of the
above since it does not leave any record of what you discarded.
Imagine that I regret doing everything since we tagged, say, v2.47.0
release and want to discard everythig on 'master' newer than that
commit. If I want to "keep" the history of failed commits that I
regret having made since v2.47.0, here is a way to do it:
$ git checkout master
$ git reset --hard v2.47.0
$ git merge -s ours --no-ff -m 'Discard everything since v2.47.0' master@{1}
The first two steps just discard the unwanted commits. The third
step is a trick to
- Keep the tree contents of the current commit (i.e. -s ours) as
the result,
- Make sure the result is recorded as a merge commit (i.e.
--no-ff), not "fast-forward" to the tip of the history I am
discarding, and
- Record the discarded history (i.e. master@{1}) as the side branch
of the resulting history.
The last part would help if I later need to merge changes that were
based on 'master' I am discarding. The presense of the side branch
makes sure that only the effects from the new work done on the
discarded history, and not from the commits such a new work was
based on (which are the commits I regret having made and I am
discarding), are taken into account when computing further merges.
