Description of problem:
kmail2 reports an error as you move the mouse over panel crossings.
With recently added bugfixes and patches, it is easier to see these other errors now. This bug appears as you move the mouse across the vertical bar separating the left and right view panels, and the right panel separating the emails from the view panel.

sample error message:
qt.qpa.xcb: QXcbConnection: XCB error: 8 (BadMatch), sequence: 2263, resource id: 123732039, major code: 130 (Unknown), minor code: 3
qt.qpa.xcb: QXcbConnection: XCB error: 8 (BadMatch), sequence: 2268, resource id: 123732039, major code: 130 (Unknown), minor code: 3
qt.qpa.xcb: QXcbConnection: XCB error: 8 (BadMatch), sequence: 2271, resource id: 123732039, major code: 130 (Unknown), minor code: 3
qt.qpa.xcb: QXcbConnection: XCB error: 8 (BadMatch), sequence: 2368, resource id: 123732039, major code: 130 (Unknown), minor code: 3
qt.qpa.xcb: QXcbConnection: XCB error: 8 (BadMatch), sequence: 2380, resource id: 123732039, major code: 130 (Unknown), minor code: 3





Version-Release number of selected component (if applicable):
mga8beta1

How reproducible:
Always

Steps to Reproduce:
1. Install mga8 beta1 from USB - classic install (32bit), add updates.
2. clone a copy of earlier email into inbox-2019/{cur/* new/* tmp/*}
3. Open a command line console, start kmail (so you can view stdout/stderr messages).
4. Move mouse over the vertical bar separating panels (the mouse will show up as a vertical bar at this time - the error messages start scrolling while you move the mouse.
5. Move mouse over the right horizontal bar separating panels (the mouse will show up as a horizontal bar at this time - the error messages start scrolling while you move the mouse.
6. Left horizontal bar is not affected.
7. last number in the scrolling errors grows larger as more errors scroll by, otherwise the other digits appear the same.
8. I also loaded kdiff3, with two different files to see if the dividing vertical bar (for kdiff3) was affected too, but this was quiet - and seems the error messages are only with kmail2