Bug 405933

Steps to reproduce:
* Set the window decorations to “Breeze” (System Settings -> Window decorations).
* Click “configure”, uncheck “Draw separator between Title Bar and Window, set “Button Size” to “Large”.
* To make it more notorious, select some color scheme that would put the title bar in a different color from the rest of the window, such as “Obsidian Coast” (System Settings -> Colors).
* Activate the desktop effect for “Wobbly Windows” (System Settings -> Desktop Behavior -> Desktop Effects).
* Try to move a window by holding the click on the title bar.

Expected behavior: should not get glitches as it moves.

Actual behavior: the space between the title bar and the window (where there would be a blue bar in earlier plasma releases) gets white artifacts at random while moving.

Setup: plasma 5.14.5, running on debian testing, X.org, mesa drivers, radeon vega 56 (amd card).