System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 445.87
Blender Version
Broken: version: 2.90.0 Alpha, branch: master, commit date: 2020-06-29 21:12, hash: rBf28e59bd742e
Worked: not sure if ever.
Short description of error
If a part of UI layout is disabled in 3d view properties (N-key panel), then mouse events over it happen as if there wasn't a panel at all (e.g. selection in 3d view works). User can also rectangle-drag selection, this is also possible in other than disabled parts of the panels.
Exact steps for others to reproduce the error
Can be tried e.g. in the marked field:
