Listens for middle mouse click events and clears the primary X selection/clipboard on detection to avoid accidentially pasting stuff all over the place.
No need to disable your precious middle mouse button bindings, no clearing of visual selections nor performance losses because of emptying the primary X clipboard periodically. With the utilization of XInput and Xlibs this has no measurable impact on performance whatsoever. No elevated privileges required. Just run within your regular users' X session.
You might need to install the libev, Xlib and X11 Input extension headers. E.g. on Debian and derivatives:
sudo apt-get install libev-dev libx11-dev libxi-dev
Build the project:
make
sudo make install
Just add xmousepasteblock to your startup script/config.
Note: If you're using any kind of clipboard manager, make sure your it does not prevent clearing the PRIMARY selection. E.g. "Klipper" does that by default with the option "Prevent empty clipboard".
In case of devices which are configured with middle mouse button hold-to-scroll (e.g. Trackpoints), it may happen that the primary selection clear action gets fired too late on older and slower machines.
You can observe the behavior by building with the DEBUG flag set (make debug), running xmousepasteblock in a shell and watching the debug output as you long press and hold the mouse buttons.
This is due to the fact that the XI_RawButtonPress event only gets fired after releasing the middle mouse button (in case the user wanted to execute a scroll action).
The only option to work around this is to disable the middle mouse button hold-to-scroll functionality on Trackpoint devices (which is often not desirable).
To do so (using libinput):
xinput set-prop <device id> 'libinput Button Scrolling Button' 0