Git rebase & Git rebase undo

git rebase is basically git merge, but in a different way.
From a repo, I :

• create a branch issue_adjust_threshold
• adjust the threshold
• make a commit Adjust the threshold
• push to remote with git push --set-upstream origin issue_adjust_threshold
• make a pull request

But on PR page it tells me there is a conflict . So I check the commit history and find out the other case owner has made two commits to master branch. I need to do git rebase.

• git checkout master, checkout to master branch
• git pull, update master branch
• git checkout issue_adjust_threshold, checkout to issue_adjust_threshold branch
• git rebase -i master, rebase master to issue_adjust_threshold
• git tells there are conflicts with a file xxx/MainTest.java
• fix the conflict, git add xxx/MainTest.java
• git commit -m "Adjust the threshold"
• git push -f

If some rebase doesn't work well, this can undo it:

git reflog 
git reset --hard HEAD@{n}

Refer to:rebase 01, rebase 02, resolve conflict 01, resolve conflict 02, resolve conflict 03, undo rebase.