bug#31415: 27.0.50; Strange behavior on Command-$ in MacOS

[Alan Third]

On Thu, May 10, 2018 at 06:30:33PM -0700, John Mastro wrote:
> By default, the "command" key in MacOS is bound to "super". If I type
> s-$, Emacs seems to wait for input that it never receives. Anything I
> type afterward appears to be ignored, except `ESC ESC ESC', which gets
> Emacs out of this state. However, even hitting `C-g' repeatedly does
> not.
> 
> The issue seems to be related to the command key rather than to "super"
> or to the command bound to the key. In my configuration, I map command
> to meta, and the same problem happens when I use M-$ to `ispell-word'.
> 
> Using `M-$' with command as meta worked until relatively recently. It
> would be great if it could be brought back or made to fail more
> explicitly.

Hmm, what’s happening is that macOS is going into a screenshot mode.
You can see the shortcuts in system preferences ‐> keyboard ‐>
shortcuts. I don’t know why you’ve not seen this before as I think
it’s been the default in macOS for quite a while now.

I don’t know if we can over‐ride this, and I don’t know that we’d want
to. 
-- 
Alan Third