git 回滚

1.  如果没有使用 push ，需要使用 git reset

2.  如果已经 push ，需要使用 git revert

3. 如果是需要回滚到某个merge 版本，需要在 git revert 的过程中，指定 -m 1

4. 一般来说，如果你在master上merge_branch,那么parent 1就是master，parent 2就是branch.

Often this will be parent number one, for example if you were on master and did git merge unwanted and then decided to revert the merge of unwanted. The first parent would be your pre-merge master branch and the second parent would be the tip of unwanted.