I can't reproduce it with the steps provided.

https://asciinema.org/a/tgKyl8dmRSrIdQ3BsW0DragCT

However if you :e within :Tutor it will wipe out the buffer contents. Here set buftype=nowrite doesn't help.

Or just do :Tutor and then again :Tutor. Here set buftype=nowrite helps.

I believe a better solution might be to come up with BufReadCmd to populate buffer properly on occasional :e and other related commands.

If you add autocmd! BufReadCmd <buffer> :Tutor

" Enables/disables interactive mode.
function! tutor#EnableInteractive(enable)
    let enable = a:enable
    if enable
        setlocal buftype=nowrite
        setlocal concealcursor+=inv
        setlocal conceallevel=2
        call tutor#ApplyMarks()
        augroup tutor_interactive
            autocmd! TextChanged,TextChangedI <buffer> call tutor#ApplyMarksOnChanged()
            autocmd! BufReadCmd <buffer> :Tutor
        augroup END
...

Together with set buftype=nowrite it would also fix issue with :e.

Well, it needs to be smarter: it should know what tutorial was loaded into the buffer and read it back within BufReadCmd.

PS, original tutorial ftw :)

Or just do :Tutor and then again :Tutor. Here set buftype=nowrite helps.

This is what I was trying to solve.

Well, it needs to be smarter: it should know what tutorial was loaded into the buffer and read it back within BufReadCmd.

Tutor is not a part of anyone's workflow, so I don't want to put too much time on it. I also support removing the new tutor btw. But until then, to avoid confusion to users, it should at least be reliable

Thanks. Let's also make it :drop instead of edit, so it works even when the current buffer is modified

Let's also make it :drop instead of edit, so it works even when the current buffer is modified

@chrisbra Why doesn't :edit work when the current buffer is modified? Can you please elaborate on that?

Also, you have not explained that change in the commit message.

Why doesn't :edit work when the current buffer is modified? Can you please elaborate on that?

Try yourself: :set modified| :e and notice the E37.

Also, you have not explained that change in the commit message.

Indeed, but now it is set in stone 🤷