Two arithmetic bugs caused wrong line totals when percentage-based allowances
or charges were used:
Bug A — Product-level (product.allowances): The percent discount was computed
as (price * pct/100) * quantity (line total), then subtracted from the unit
price and multiplied by quantity again — discount applied twice.
Bug B — Item-level (itemAllowances) with basisQuantity != 1: The percent was
applied to price * quantity instead of price * quantity / basisQuantity.
Fix: LineCalculator and XML pull providers now pass context-appropriate
IAbsoluteValueProvider wrappers (perUnitProvider for product-level,
itemBasisProvider for item-level). Allowance.java uses RoundingMode.HALF_UP
in getPercent().divide(100). BasisAmount in XML is formatted via
currencyFormat().
Files changed:
- LineCalculator.java: perUnitProvider, itemBasisProvider in allowance/charge loops
- Allowance.java: RoundingMode.HALF_UP, scale 18
- ZUGFeRD2PullProvider.java: correct providers, format BasisAmount
- OXPullProvider.java, DAPullProvider.java: perUnitProvider for product-level
- CalculationTest.java: @Test on 5 methods, 4 new regression tests
Verification: mvn test -pl library -Dtest=CalculationTest
Full PR description with before/after XML proof: see .project/PR-allowance-charge-fix.md
(Test evidence files in C:\temp\mustang-test\ are for PR attachment only, not in repo.)
Co-authored-by: Cursor <cursoragent@cursor.com>
dd32514938