I was messing around with lua and löve, when running a lua file that draws a (non fullscreen) window compositing is disabled causing some glitches.

STEPS TO REPRODUCE
1. install lua and love (e.g sudo zypper in lua51 love) 
2. put the following code in the file, and save it.

function love.draw()
   love.graphics.print("Hello, World!", 400, 300)
end
 
3. navigate to where the .lua file is and run it with love .

OBSERVED RESULT
Compositing is disabled making windows lose their shadows, margin widget is disabled, firefox can't render the current webpage.

EXPECTED RESULT
Compositing should not be disabled for non fullscreen applications.

SOFTWARE/OS VERSIONS 
Linux/KDE Plasma: openSUSE Tumbleweed
(available in About System)
KDE Plasma Version: 5.21.3
KDE Frameworks Version: 5.80
Qt Version: 5.12.2