Created attachment 182965 [details]
Unexpected “move” cursor inside KolourPaint window

Title: Dragging from outside the canvas area in KolourPaint triggers unexpected window shrink + move

KDE Plasma version: 5.27.12 
KolourPaint version: 23.08.5 
OS: Kubuntu 24.04  
Qt version: 5.15.13
KDE Frameworks: 5.115.0

Steps to reproduce the issue:
Launch KolourPaint.
Left-click anywhere in the white area outside the main blue canvas (the empty white margin around the drawing space).
Begin to drag the mouse.

Expected behavior: Nothing should happen—or at most, the cursor should remain idle unless interacting with a drawable surface or UI element.

Actual behavior: 
As soon as I begin dragging the mouse cursor changes to a four-arrow “move” icon (typically used for moving windows).
The KolourPaint window shrinks to approximately one-third of the screen size.
The window detaches and float with the cursor until I release the mouse button, effectively initiating an unintended move action for the window.

This does not occur in other KDE applications, so it appears specific to KolourPaint’s unhandled margin area triggering a KWin-level window move.

The attached screenshot shows the unexpected 'move' cursor active within the interior of the KolourPaint window—positioned near the center, away from any window border.