What you describe is normal behavior, even if it appears confusing. It's an
"impedance mismatch" between terminal.app and being in a "curses" window.
Terminal doesn't "see" selected text and hence Command-C is disabled. This
is the opposite for a basic shell where terminal sees the text because
it controls selection. You can see this by pulling down the Edit menu and
seeing Copy grayed out. As far as how xterm-mouse-mode interferes with
Command-C I'd have to disable it myself and see what's going on. Not sure
how much value that adds, though. If you enable xclip, you'll get what you
want being inside Emacs, after all, using M-w gets your selected text
copied to the pasteboard.

On Fri, Dec 13, 2024 at 11:35 AM Filipp Gunbin <fgunbin@fastmail.fm> wrote:

> On 13/12/2024 09:21 +0200, Eli Zaretskii wrote:
>
> >> From: Ship Mints <shipmints@gmail.com>
> >> Date: Thu, 12 Dec 2024 15:31:00 -0500
> >> Cc: fgunbin@fastmail.fm, 74833@debbugs.gnu.org
> >>
> >> I have xterm-mouse-mode enabled when in tty mode on macOS and it does
> work for clicking/selecting but
> >> this is independent of integrating the kill ring with the pasteboard. I
> am unaware of how to test the
> >> completeness of the xterm mouse protocol support, however.
> >
> > So why is this an Emacs bug?  It sounds like the OP expects something
> > to happen which shouldn't, because the xterm protocol for selections
> > and the clipboard are not supported by Terminal.app?  In that case,
> > this could be at best a feature request, not a bug.
>
> I'll try to explain differently.
>
> Without xterm-mouse-mode you can copy/paste from/into Terminal.app
> window, looks like Terminal.app gives this ability on its own.  This is
> not integration with Emacs kill ring, no.  Emacs cursor does not react
> to mouse clicks, and selection happens with OS mouse pointer.  Paste
> works rather slow (bad idea to paste large chunks of text), but
> tolerable.
>
> Now, yesterday my daily master build got me xterm-mouse-mode enabled, so
> I did some testing just out of curiosity.  Most of the things work,
> including clicking and selection.  However, Command-C now just doesn't
> copy text to OS clipboard.  And it's non-obvious that you should disable
> xterm-mouse-mode to be able to copy.
>
> That's why I filed this bug - because previous behavior was not ideal
> but working, and now only paste works.
>
> Maybe we should just avoid enabling xterm-mouse-mode in Terminal.app.
> Maybe functionality of xclip should be in core.
>