Inserting newline sometimes causes strange renders

[ChristopherChudzicki]

Thanks for this great library! I came across the behavior below today. It seems as if inserting text renders differently than typing the text from start to finish (or copy-pasting it).

For example, below, the text is

insert one newlin
e

but looks differently if typed from start-to-fnish or if the newline is inserted.

This seems to happen when inserting a non-newline character would cause wrapping to occur.

[Andarist]

I'm afraid that I won't have time to look into this - but I would gladly accept a PR fixing the issue.