[FIX] point_of_sale: tax calculation

Inconsistencies can arise between the tax calculation performed in the
PoS and in the backend (e.g. in a SO). For example:
- Unit price: 9.479
- Tax: excluded, 5.5 %
- Buy 5 units
- Round globally

In the backend, the result is 47.40 + 2.60 = 50.00
In the PoS, the result is 47.40 + 2.61 = 50.01

We make the PoS apply the same logic than in the backend. First, at the
level of the `compute_all` method, especially to use the appropriate
rounding precision before starting the calculation (so we move the
rounding of `total_excluded` after the rounding precision adjustment).
Then, by calculating the taxes amount as the difference between
`priceWithTax` with `priceWithoutTax`. This is mandatory since they
contain the result of `compute_all` in which the rounding logic has
already been applied.

opw-680891

0 files changed, 0 insertions, 0 deletions