bug#28215: 26.0.50; Option-Clover-H

[Devon Sean McCullough]

> On Aug 25, 2017, at 4:24 AM, Alan Third <alan@idiocy.org> wrote:
> 
> On Thu, Aug 24, 2017 at 08:34:47PM +0100, Alan Third wrote:
>> It looks like the problem is at nsterm.m:6122. I don’t understand what
>> the point of that code is. It looks like it’s trying to work around
>> some problem with different keyboard layouts.
> 
> Attached is a patch that adds the M-s-h shortcut, and removes the code
> that treats the super key as special.
> 
> If anyone can tell me why that code was there that would be great, but
> it seems to work fine without it. It’s been there since the NS port
> was merged into GNU Emacs, so I wonder if it’s required on some old
> *step implementation.

Could it be trying to support
Apple > System Preferences... > Keyboard > Input Sources > + > English > DQ 
Dvorak - Qwerty ⌘
which IIRC is a Dvorak layout but with Qwerty Command-keychords
already ingrained in Mac users' muscle memory?

        Peace
                —Devon

P.S. DV Dvorak layout vs. DQ Dvorak - Qwerty ⌘ layout
     Apple key labels -> Emacs 26.0.50 events

        Dvorak  Qwerty  DV      DQ
        H       J       h       h
        D       H       d       d
        ⌘H      ⌘J      s-h     s-j
        ⇧⌘H     ⇧⌘J     s-H     s-H
        ⌥⌘H     ⌥⌘J     M-s-˙   M-s-∆
        ⌘D      ⌘H      s-d     s-h
        ⇧⌘D     ⇧⌘H     s-D     s-D
        ⌥⌘D     ⌥⌘H     M-s-∂   M-s-˙

    Special characters in all layouts per Keyboard Viewer or (setq 
ns-option-modifier 'none)
        Key Chord       Character       Unicode Name
        Option-D        ∂               PARTIAL DIFFERENTIAL
        Option-H        ˙               DOT ABOVE 
        Option-J        ∆               INCREMENT

P.P.S. /System/Library/Input Methods/KeyboardViewer.app shows keyboard layout, 
tracking input source & bucky bit state
in real time.  Turns out there are eight different Option layouts, one for each 
Control/Shift/Command combination.
Perhaps C-q quoted-insert should access these MacOSX alternate layouts by 
binding ns-option-modifier to none for NS,
similarly current-input-mode/set-input-mode for tty input and finally insert 
the next input key sans bucky bits.