bug#20926: 25.0.50; Quotation marks always display as hard quotes

[Artur Malabarba]

> Go to that left quotation mark on the decomposition line, and type
> "C-u C-x =".  That should give you a hint about what's going on there.
>
>> So I know that emacs can display them.
>
> Yes, but does Emacs know that?
>
> The display table is used when Emacs decides at startup that these
> characters cannot be displayed.  The code which makes that decision is
> in 'set-locale-environment' (see mule-cmds.el, and search for
> "char-displayable-p"), which is run at startup.  Can you see what's
> going on there?

I'll try to follow up on these later today.

> Also, do you call 'set-locale-environment' in your non-Q session?

Not that I'm aware. And grep shows no instances of it inside my .emacs.d