I often use nested lists in my answers and came across the following problem:
When entering a nested list like
* A * B
pressing Shift+Enter causes the auto formatter to flatten the list to
* A * B * List item
Note that this does not happen when simply pressing Enter, but it can be quite frustrating when you have built a more complex nested list hierarchy and accidentally press Shift during line breaks.
Instead of clamping all spaces in front of a bullet into a single one, compute the hierarchy level for every bullet and set spaces accordingly, while inserting new list item in the current hierarchy level.
EDIT: I'm using Firefox 54 (64 bit) on Ubuntu