Eli Zaretskii <eliz@gnu.org> writes:
> What was the last version of Emacs in which this worked on GNU/Linux?

I've only gone back as far as 24.  The Debian box I was testing on
isn't accessible to me now that the holidays have started.  I'm able
to do the following: test on FreeBSD 10.2, test on GNU/Linux by
running it remotely with X forwarding, test on GNU/Linux by running it
through a VM.

Joseph