git从历史上的某一次提交处建立分支

$ git log --oneline --all --graph --decorate
* 1efcf18 (HEAD -> master)  commit
* 6a7ace8  commit
* 3be5879  commit
* 3d1a4d4  commit

$ git branch
* master

$ git branch dev 3be5879

$ git branch
  dev
* master

$ git log --oneline --all --graph --decorate
* 1efcf18 (HEAD -> master)  commit
* 6a7ace8  commit
* 3be5879 (dev)  commit
* 3d1a4d4  commit

$ git checkout dev
Switched to branch 'dev'

$ touch dev_file

$ git add .

$ git commit -m 'dev commit'
[dev c7b5ce1] dev commit
  file changed,  insertions(+),  deletions(-)
 create mode  dev_file

$ git log --oneline --all --graph --decorate
* c7b5ce1 (HEAD -> dev) dev commit
| * 1efcf18 (master)  commit
| * 6a7ace8  commit
|/
* 3be5879  commit
* 3d1a4d4  commit