Comment 5 for bug 868839

I'm sorry I thought I replied to this a long time ago but apparently I didn't.

No the "fix" you pointed out to me (lp:667316) is exactly why I filed this in the first place. I didnt like the way it was implemented. What that does is require me change the decimal precision of ALL my accounts to 5 in order to enter a tax rate with 5 decimals. However, I want all of my accounts to have a decimal precision of 2 not 5. The tax rate is the only thing that needs to be stored with 5 decimals.

With that code:

(1)
If account precision is set to 5 to allow me to use a tax rate of 7.975% (or 0.07975). Then an invoice looks like this:

Sub Total: 1,234.56000
Tax (7.975%): 98.45616
Total: 1,333.01616

(2)
If account precision is set to 2 the tax rate is rounded to 7.98%. Then the invoice looks like this:
Sub Total: 1,234.56
Tax (7.98%): 98.52
Total: 1,333.08

(3)
What I should be able to do is leave account precision at 2 but still be able to use a tax rate with precision of 5 that rounds to 2 after the rate is applied to the total:
Sub Total: 1,234.56
Tax (7.975%): 98.46
Total: 1,333.02

As you can see, I get three different Totals depending on the scenario. The third one is what I would like to do as this, as far as I know, is how sales/purchase taxes are commonly calculated over here.

With that said, no big deal if there is no intention to change the behavior. The code change I instituted above allows me to get by just fine for now. I just think there is something wrong with tying account precision with tax rate precision. They are two completely different things.