如何在提交前恢复并进入上一阶段

Question

I am new at version control system (git). I did a mistake and when I realize it happen its too late. what I did

(1) commit current work 
(2) git pull --rebase origin master

Then I go to a previous commit using

(3) git checkout 858223adcac47288c44c4c07fbc3938773d778b8

Now I need to go the previous stage(1) before committed. And I really don't know how to go there. That's mean I want to go my master and undo the rebase .
I heartily thank if anyone tell me how to do this.

Answer 1

git saves history of refs (read branches ) mostly for this kind of scenarios when you want a commit that is no longer reachable from any of the current refs .

Unless enough time passed or you explicitly made reflog entries expire and garbage collect, the history is available by issuing git reflog <branch> outputting changes to branch to in form of <sha> <action description leading to changing value of branch> starting with most recent one.

Find the one you want to get back to (probably one that was prior to the commit you mentioned), examining:

git reflog master

Check it out to double check the contents:

git checkout <sha>

Move to master and reset master to that commit (caution that hard reset is potentially dangerous/troublesome if used incorrectly):

git checkout master

git reset --hard <sha>

---

Some notes:

How git-rebase works. This will help to understand how no longer reachable can arise during rebase https://git-scm.com/book/en/v2/Git-Branching-Rebasing

It's also possible to create another commit on top of rebased commit that effectively undoes the pulled part, but that's less practical and noted for completeness only.