This fixes:
* ZDI-CAN-19866/CVE-2023-1393: X.Org Server Overlay Window
Use-After-Free Local Privilege Escalation Vulnerability
If a client explicitly destroys the compositor overlay window (aka
COW), the Xserver would leave a dangling pointer to that window in the
CompScreen structure, which will trigger a use-after-free later.
PR: 270540
Approved by: x11 (maintainer)
MFH: 2023Q2
Security: 96d84238-b500-490b-b6aa-2b77090a0410
0449a8492b