Entering four dashes sometimes causes unexpected behaviour

[justin-sinclair-aus]

If you enter 3 dashes '---' it creates a line separator (yay!).

However if you accidentally enter 4 dashes '----' it sometimes creates 2 line separators. When this happens, if you hit delete to remove one of the separators you can get stuck in a strange editor state where it highlights the block of 2 lines of dashes and you have to delete all of the dashes to clear it (I have been able to reasonably consistently reproduce this, but not now, so no screenshot, sorry).

Other times, it doesn't create 2 line separators, but if you then keep on typing new lines and then try and create another line separator, it will then make the copy you type bold and large (see screenshot).

[astoilkov]

Thank you for the detailed description.

I will try to replicate and fix the issue soon.

Thanks!