Income tax suddenly dissapears -> here is why

I thought this was something people may have misunderstood, but No, it’s a real evil bug (my fault -> sorry), which I’ve finally replicated and tracked down. As far as I know, it only happens when some value goes to zero, most likely your GDP. According to the equations, this shouldn’t matter because even if GDP is zero, you should earn 20% of your income tax. (subject to tax evasion)
but there was a bug where the calculations for how to scale taxes by GDP allowed GDP to be a negative number. It doesn’t seem to be negative, or show on a graph as negative, but in that brief gap between being calculated and set to a minimum of zero, the error gets ‘propagated’ through the network and screws up the numbers.
The end result can be zero taxes.
But there is good news, i think I’ve found it, identified it and fixed it. I’m going to test it properly, and then it should be fixed in the next patch.

thank you thank you thank you