Resolve issues found by PVS

[demoth]

Hi

I have run PVS against the code. Attaching the report.

https://docs.google.com/spreadsheets/d/1sR1PY_hrebTtRRAk9Atur7JaDGGoGLHkFGY8au54dGY/edit?usp=sharing

[NeonKnightOA]

Hi! I'll take a look at these and fix whatever's found.

[NeonKnightOA]

Hmmm... there were many changes to the code between 2019 and today. What does PVS output in today's code?

[Yamagi]

Properly mostly the same. But I can't check, I don't have a PCS Studio license and there open source programs requires adding spam to the README.md...