I'm using Ubuntu 16.04 (and Rstudio 1.1.463) on a thinkpad X220, one with a trackpoint mouse. Today this started happening:
When I press the middle (scroll) button above my trackpad, with the intention of using the trackpoint to scroll through my code, the button click instead pastes whatever (if anything) is in my clipboard. This is only happening in Rsutio.
Turns out apparently something similar is the desired behaviour in Ubuntu, and sure enough, on my external mouse, pressing down on the scroll button pastes (I've never used this functionality). But the scroll button on the trackpad does not have this behaviour anywhere else: in any other programme (and in Rstudio up until today), pressing it allows me to scroll.
I thought this behaviour appeared suddenly, without any changes in the software or settings, but that's not true: an ubuntu update happened this morning, which is could be the cause. I believe the following packages were installed:
firefox. I have no idea what most of these do, but I could try to rollback an offending one if someone could point me to the potential cuplrit?