this is a solution for anyone who has a problem with accidental code changes. It only affects users on Linux with GTK. The accidental code changes happens, if I use the scroll wheel on my mouse. The wheel is also a button, the "middle" button. The middle button pastes content on click. Unfortunately, clicking the button happens sometimes on scrolling and messed up the code. You can disable the middle button temporary with this command:
xmodmap -e "pointer = 1 25 3 4 5 6 7 8 9"
To persist this behavior, edit ~/.Xmodmap and add
pointer = 1 25 3 4 5 6 7 8 9
I hope, it helps you, too.