Error with mixed LI and CODEBLOCK

Steps:

1. Switch to source code and input the markdown content:

* aaa

        cd 
        ls

* bbb

        xxx
        yyy

2. Switch to editor (or preview, or save)

3. Edit again and switch to source code

4. Then we get

* aaa`  cd 
  ls
`
* bbb`  xxx
  yyy`

5. Preview or save the page again, then the layout is wrong.