UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/604.5.6 (KHTML, like Gecko) Version/11.0.3 Safari/604.5.6

Steps to reproduce the problem:
1. Paste the code from the very bottom of  https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Editable_content/Rich-Text_Editing_in_Mozilla into a .html file.
2. Open that html file
3. Check "Show HTML"
4. Paste this into the editor:

<span flagged="">topic 1</span><br><ul><li>defa</li><ul><li hide-as-child=""><span style="color:rgb(156, 39, 176);">hij</span></li><ul><li><span style="background-color:rgb(156, 39, 176);">klma</span></li><li><span style="background-color:rgb(156, 39, 176);">aoeu</span></li><li><span style="background-color:rgb(3, 169, 244);">aou</span><br></li></ul><li hide-as-child=""><span style="text-decoration-line:underline;">aoeu</span></li><li>aoue</li></ul><li hide-as-child="">aoeu</li></ul><br><span style="color:rgb(0, 150, 136);">

5. Uncheck "Show HTML"
6. Select the 3 very innermost bullet points
7. Press the outdent button

What is the expected behavior?
All bullet points should retain their styling when outdented.

What went wrong?
Some nested bullet points lost their styling when outdented.

Did this work before? N/A 

Chrome version:  64.0.3282.167 (Official Build) (64-bit)  Channel: n/a
OS Version: OS X 10.12.6
Flash Version: 28.0.0.161

Neither Firefox 58.0.2 (64-bit) nor Safari 11.0.3 (12604.5.6.1.1) on my mac have this issue.

I'm using electron (runs on chromium) to build a text editor. This bug is moderately important to my users.

Thanks!
 

Deleted: OutdentUnformats.mov 5.0 MB

	OutdentUnformats.mov 5.0 MB View Download