Oh, I didn't notice that. Because my Ctrl+Space is occupied by the input method switch.

I don't think that a code hint is helpful when nothing has been typed. It's better to having no code hint than having a not so useful code hint list floating around.

However, I think we can still fix this by checking the `lastContext`.

If lastContext is not `null`, we know that the user has previously typed something and have some hints. So we can get ride of the hint list this time.
If lastContext is `null`, we know that the user didn't get any hints the last time. We can now show him some hints anyway, if he requires.

I've added a commit.