Fedora 26: Configure Middle Button Emulation

I have a 3-button Logitech USB-PS/2 Optical Mouse but the middle button doesn't work. My main use is automatic copy and paste.
What you can do to do that is enable the emulation mode (press at once the left and right buttons).

Check your device ID with:

> xinput list

Virtual core pointer                        id=2    [master pointer  (3)][...]
  Logitech USB-PS/2 Optical Mouse             id=12    [slave  pointer  (2)]

then use to list its properties:

> xinput list-props 12
[...]
    libinput Scroll Method Enabled (293):    0, 0, 0

then enable it:

> xinput set-prop 12 297 1

or better (change-proof):

>xinput set-prop "Logitech USB-PS/2 Optical Mouse" "libinput Middle Emulation Enabled" 1

If you want to make this permanent, add it to your .bashrc or similar or to the configuration in /etc/X11/xorg.conf.d.

References
Updated from: https://ask.fedoraproject.org/en/question/47238/configure-auto-copy-paste/