adding space in the text editor

Hello, I don't think is a bug but I don't know where to post it:

In this thread I tried to paste " & n b s p ;" (space added intentionally in order to visualize it here) but when I did it, the literal text was not added but a space and sometimes the cursor jumped to the next line. If I wrote the literal text, a space is showed in the message preview

If I try to submit a message only with that literal code I got an error:

I also tried using the inline code (I had to pasted here as source code):

[tt] [/tt]

and I get some kind of underscore:

Tested in Google Chrome (latest) with and without extensions.

  in [tt]