Explanation
This occurs to every side that touches the boundary of plasmashell
’s desktop:/
window. This means that every window which touches the boundary of the display, or a panel:
Examples
-
Top-Left
-
Top-Right
-
Bottom-Right
-
Bottom-Left
-
Full-Screen
Importance
This is really problematic when attempting to acquire 16:9 screenshots.
It’s not the same issue exactly, but I wonder if this is somehow connected to the same underlying cause as 498597 – Using Active Window or Select Window mode, window top corners looks weird when using light variant of Breeze - something about borders not being captured or rendered exactly as they are on-screen?
I see the effect described in that bug report on your screenshots as well - although that report mentioned only Breeze Light, and yours seems to be happening on Breeze Dark?
1 Like
@johnandmegh, actually, in this case, Spectacle is capturing exactly what’s rendered. When I tile a window to an edge, I see the window border wrap around the title bar, then stop at the window content, as depicted in the screenshots. I expect that this is a bug in the Breeze KWin SSDs. 
Thanks for linking that issue, though, because I’ve encountered that too, and that saves me reporting it myself. x