I don't see this behavior with Emacs 26.3 on macOS 10.15  I also don't
recall seeing anything like this with previous versions of Emacs or macOS.
However, I also disable many of the macOS shortcuts via preferences ->
keyboard -> shortcuts.

I ran Emacs with -Q to ensure it wasn't something in my config, so I
suspect either you have something in your Emacs config or you need to
disable the shortcut at the macOS level.

On Wed, 30 Oct 2019 at 06:32, Mark H. David <mhd@yv.org> wrote:

> I frequently type Command+T by mistake in Emacs because in browser apps
> (particularly Chrome) it's used for creating a new tab, and I do that so
> often, I must do it by mistake. I almost never change fonts, and never with
> command+t. Ever.
> So, I looked into this a bit, and it's a documented "feature" for Emacs on
> MacOS (see: https://www.emacswiki.org/emacs/SetFonts#toc14) and for MacOS
> generally for documents (see: https://support.apple.com/en-us/HT201236).
> Apple's MacOS doc says: Command-T: Show or hide the Fonts window.
>
> In various apps with document windows (e.g., build-in TextEdit as well as
> Emacs) it is supposed to pop up a window thingee that lets you choose
> fonts. Whatever, I never use. I always just want to get rid of it.
>
> Here's the annoying and buggy part with respect to Emacs: you cannot hide
> it from the keyboard.  It's supposed hidden by doing a second Command+T.
> That works in other apps, e.g., TextEdit, but it doesn't work in Emacs. In
> addition, you cannot select the popup "windoid" that results, even by
> Command+`. Even if you do select the windoid somehow (e.g., by clicking
> it), you cannot dismiss it by typing Command+W.
>
> So, this is super annoying and a bug.
>
> Here's my Emacs version.
>
> "GNU Emacs 25.3.1 (x86_64-apple-darwin13.4.0, NS appkit-1265.21 Version
> 10.9.5 (Build 13F1911)) of 2017-09-12"
>
> I'd appreciate knowing if this is a known bug, if it's fixed upstream, and
> if anyone can share any workaround.
>
> Thanks,
>
> -Mark
>
>

-- 
regards,

Tim

--
Tim Cross