Residual Invoice Amount Incorrect V6

[Mike]

In Order to recreate the incorrect residual amount please follow these steps:

1. Create payment terms (33% now, 33% in 42 days, balance in 84 days)
2. Create partner/address/contact
3. Create product AF1, unit price 100 GBP, with tax code OVAT S (20%)
4. Create new invoice, add parner and AF1 product, select payment terms
5. Click Calculate tax
6. Click Validate invoice

The results I observed:
1. Payment terms OK
2. Partner added OK
3. Product added OK
4. Invoice created OK
5. Tax calculated OK - show expected tax amount
Invoice validated without error - BUT residual value show only the tax amount

The results I expected:
1-4 As above
5. When the invoice was validated, I expected the residual amount to show the sum of invoice base value + calculated tax (as per v5)

This error not only reports the residual value incorrrectly on the invoices, but as a result prevents receiving the correct payments against the invoices.

Possible error location:
addons/account/invoice.py Line 97
result[invoice.id] = m.amount_residual_currency
I'm guessing the tax amount is the last in the iteration loop and there's no form of adding up in there so its literally using the last one.
Also comparing this function to the function in version 5 there appears to be alot less code which i find odd.

Best Regards,
Mike
Smart IT Ltd