Problem with retaining formatting in a list

[dgavey]

Steps to reproduce:

1. Create a list of bulleted items
2. Apply some formatting to the whole list
3. Remove an inner item from the list using the backspace key
4. Press enter and start typing

Expected result: Formatting would be retained in new list item

Actual result: Formatting is stripped.

An interesting workaround is if you move the cursor left and then back again and hit enter the formatting is retained. So I think it's something to do with the range being set after a backspace.

I spent some time trying to track down where in the code this is happening with not much luck. If you can point me in the right direction maybe I could get a PR ready for you.