Why has X11 system clipboard interoperability changed from Emacs 24 to 25?

Why has X11 system clipboard interoperability changed from Emacs 24 to 25?

[itchybeard]

In the Emacs 24 GUI for X11-based desktops I can set
`'(x-select-enable-clipboard nil)` in my config to prevent standard kill ring
commands like `yank`, `kill-region`, and `kill-ring-save` from affecting the X11
system clipboard, and it still allows me to explicitly interoperate with that
clipboard by invoking the commands `clipboard-yank`, `clipboard-kill-region`,
and `clipboard-kill-ring-save`.

But in Emacs 25 the variable `x-select-enable-clipboard` is replaced by
`select-enable-clipboard` which when set to `nil` in my config yields different
results: *all* interoperability with the X11 system clipboard is disabled. Even
the commands `clipboard-yank`, `clipboard-kill-region`, and
`clipboard-kill-ring-save` revert to using Emacs' kill ring exclusively, in fact
they have identical effects to using plain `yank`, `kill-region`, and
`kill-ring-save`, so what's their purpose when `select-enable-clipboard` is set
to `nil`?

What is the reasoning behind this change in behavior, and is it possible to
replicate the Emacs 24 behavior in Emacs 25 using built-in configuration
options, or will I have to start using a custom solution like simpleclip? I want
a kill ring and X11 system clipboard that are independent, and I want
interoperability between them but only explicitly, e.g. to use `yank` to paste
content from the kill ring and `clipboard-yank` to paste content from the X11
system clipboard.

There is an open bug related to this changed clipboard behavior:

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=27442

Re: Why has X11 system clipboard interoperability changed from Emacs 24 to 25?

[Eli Zaretskii]

> Date: Thu, 17 Aug 2017 02:42:30 -0400
> From: itchybeard <itchybeard@protonmail.com>
> 
> But in Emacs 25 the variable `x-select-enable-clipboard` is replaced by
> `select-enable-clipboard` which when set to `nil` in my config yields different
> results: *all* interoperability with the X11 system clipboard is disabled.

AFAIK, that was not supposed to happen.

In any case, this is not the proper place to discuss bugs in Emacs,
please submit a detailed bug report using "M-x report-emacs-bug RET".

> There is an open bug related to this changed clipboard behavior:
> 
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=27442

I'm not sure that bug describes the same problem, as it talks about a
specific function that only yanks, whereas your complaint seems to be
much more general.

Re: Why has X11 system clipboard interoperability changed from Emacs 24 to 25?

[Glenn Morris]

itchybeard wrote:

> In the Emacs 24 GUI for X11-based desktops I can set
> `'(x-select-enable-clipboard nil)` in my config to prevent standard
> kill ring commands like `yank`, `kill-region`, and `kill-ring-save`
> from affecting the X11 system clipboard, and it still allows me to
> explicitly interoperate with that clipboard by invoking the commands
> `clipboard-yank`, `clipboard-kill-region`, and
> `clipboard-kill-ring-save`.
>
> But in Emacs 25 the variable `x-select-enable-clipboard` is replaced
> by `select-enable-clipboard` which when set to `nil` in my config
> yields different results: *all* interoperability with the X11 system
> clipboard is disabled. Even the commands `clipboard-yank`,
> `clipboard-kill-region`, and `clipboard-kill-ring-save` revert to
> using Emacs' kill ring exclusively, in fact they have identical
> effects to using plain `yank`, `kill-region`, and `kill-ring-save`, so
> what's their purpose when `select-enable-clipboard` is set to `nil`?

You did not say exactly what version of Emacs you are using.
If 25.1, this sounds like https://debbugs.gnu.org/25145, fixed in 25.2.

Re: Why has X11 system clipboard interoperability changed from Emacs 24 to 25?

[itchybeard]

-------- Original Message --------

> You did not say exactly what version of Emacs you are using.
> If 25.1, this sounds like https://debbugs.gnu.org/25145, fixed in 25.2.

Sorry, I'm using 25.1 which is my distro's latest package, so I'll try
installing 25.2 from upstream. Thanks for informing me of that bug report, I
missed it when searching the database.

Re: Why has X11 system clipboard interoperability changed from Emacs 24 to 25?

[itchybeard]

The testing version of my distro has packages for 25.2 so I installed those, and
X11 system clipboard interop using the aforementioned commands now works exactly
as it did in Emacs 24, so I'm quite happy. Thanks again.