The Problem:
Strangely enough, I've had this problem on every operating system I've used, including Windows.
Sometimes windows open not-quite-fullscreen. I don't know why they do that, I certainly didn't leave the app like that last time I closed it. There's usually like a pixel or two between the top edge of the window and the edge of the screen, as well as at the bottom.
This is extremely annoying because I don't usually look that closely, and then more often than not, when I try to click the "X" in the top right corner, I actually miss the window and click whatever is behind it - usually the "X" of another window that I didn't want to close.
The most recent case of this was Yakuake's keyboard shortcut config window. I ended up closing my browser instead, with lots of open tabs.
This shouldn't be possible to happen at all. I see zero legitimate use cases for windows doing that. Sure, there is snapping, but that only applies when I'm moving the window myself, not when a new window opens.
Question:
Is there some way to configure xorg/kwin to prevent windows from opening only almost fullscreen? Say, a 10px margin at the screen edges (except at the bottom because of the task bar) where if the window is within all of them, it automatically gets properly maximized? Again, KDE's built-in snapping doesn't work because I'm not moving the window myself.
Edit: Yes, I know about kwin window rules. No, they don't offer a solution.
