System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1080 with Max-Q Design/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 466.77
Blender Version
Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-06-28 22:09, hash: rBe1a719c0433b
Short description of error
Enabling or disabling of the Paint Mask and Vertex Selection modes is missing an undo push
Exact steps for others to reproduce the error
Enable Paint Mask
Paint on the model
Undo
Result: Both the paint and the paint mask mode are undone

