bug#33320: 27.0.50; `describe-key' fails to display help for C-mouse-3

["N. Jackson" <nljlistbox2@gmail.com>]

At 09:57 +0200 on Friday 2018-11-09, Eli Zaretskii wrote:
>
> C-mouse-3 is a kind of prefix key, and we never display
> help for prefix keys, we always wait for the user to type the complete
> key sequence, which in this case includes menu selection.

Oh, I see. That makes sense, now that you say it!

Perhaps the documentation for `describe-key' should mention that? It
might say something about it displaying that final hyphen while it is
waiting for more input, when a complete key command has not yet been
entered for it to display help on.

> You need to select one of the menu items by clicking on it, then you
> will see the help for that item.

Right. I understand that now. [Although in this case I wasn't looking
for the documentation of one of the menu items, I was looking for the
documentation for whatever function pops up the menu itself.]