Bug 470647

SUMMARY
When shading a window then enabling/disabling maximize (from right-click menu or with Meta+PageUp shortcut), the window doesn't un-shade.

Since maximizing a window is about changing its size/geometry (and not only the position), I think it makes sense to un-shade it to explicitly display its new size/geometry.

Also, shading a window may be unwanted (like selecting the option from Taskbar without understanding what it does, on an application that is in background and hidden by another window), it's may not be easy to find how the un-shade the window, and maximizing the window may be the first solution for most users (to "reset" the window).

Note: This is the behaviour in Xfce, enabling/disabling the maximizing of a window also un-shade it.

STEPS TO REPRODUCE
1. Open any (not maximized) window
2. Shade a window (by right-clicking on window top and selecting "More Actions > Shade")
3. Maximizing the window (Top arrow, or Meta+PageUp if it's still the shortcut)

OBSERVED RESULT
The window fills the screen in width but is still shaded.

EXPECTED RESULT
The window would un-shade, and so, fills the complete screen.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Neon Live (20230504-0714), Manjaro 23.0.0
KDE Plasma Version: 5.27.5
KDE Frameworks Version: 5.106.0
Qt Version: 5.15.9
Graphics: X11 on Neon, Wayland on Manjaro