Jambunathan K <kjambunathan@gmail.com> writes:

>> Good idea.  There is `post-self-insert-hook' but there is no
>> `pre-self-insert-hook' that would check whether the point is in 
>> an invisible area of the buffer, and send a warning about this.
>
> In org-self-insert-command check for visibility at point and take the
> required action.

That's it.  Thanks!

Here is a dummy patch that prevents the user from editing invisible
parts of the buffer.  It doesn't prevent query-and-replace commands.

Can people test it and comment it?

Maybe throwing an error is a bit too much.  Maybe preventing all 
kind of edition in invisible parts of the buffer is too much as 
well -- looking forward reading comments on this.

Thanks,