Bug 454068

SUMMARY
When taking a screenshot of the current window a black box will appear under the cursor the next time the cursor state changes. This behaviour is new in the Plasma 5.24.90 beta.

For example, taking a screenshot with the cursor inside a textbox where it is an IBeam, and then moving it outside of the textbox where it becomes a regular pointer again, will make a black box appear under the cursor. The inverse is true as well, taking a screenshot of the current window and then moving the mouse into a textbox where it will turn into an IBeam will put a black box under it. Moving the cursor back into this box or in general changing the cursor state will not remove the black box, it only goes away when a certain handful of actions are performed. For example, dragging a window's titlebar or holding the Alt and dragging a window will make it disappear, but it only disappears AFTER the left mouse button has been lifted. Activating an effect such as changing desktops, or toggling the Overview effect, will also remove the black box, but in the case of the Overview effect it is still present until either an element of the Overview effect is interacted with (such as a window, or the Virtual Desktop list, etc), or when the effect is cancelled. There are other various weird circumstances too where the box will disappear, such as opening an application from the Dashboard applications view, where the black box will disappear once the newly opened window is moused over.

Unfortunately I can't get a screenshot of this, as when trying to take a rectangle region screenshot the black box moves as I move the mouse cursor, and when taking a regular screenshot the black box is not visible I tried Active Window, Current Monitor, Entire Desktop, and Window Under Cursor. The black box does not show up in any of them.

This happens seemingly regardless of any settings. I tried toggling copying the screenshot to the clipboard and toggling capturing mouse cursor for example.

STEPS TO REPRODUCE
1. Take a screenshot of the current window
2. Move the mouse cursor around, for example in and out of a textbox
3. A black box will appear under the mouse cursor, drag a window using its titlebar or with the window dragging shortcut (for example holding Alt and left click)
4. Once the left mouse button is released, the black box should disappear


OBSERVED RESULT
Black box appears under mouse cursor when a single window screenshot is taken.


EXPECTED RESULT
No black box should appear under mouse cursor, consistent with behaviour in Plasma 5.24 and below.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.17.9-zen1-1
KDE Plasma Version: 5.24.90
KDE Frameworks Version: 5.94.0
Qt Version: 5.15.4

ADDITIONAL INFORMATION
Have not tried X11