Invoice grand_total and base_grand_total differ while in the same currency

[AntonEvers]

There are a lot of preconditions. I don't know which is the one that eventually causes the rounding difference, so bear with me.

Preconditions

1. Magento CE develop branch
2. Create a product with a price of 5.99
3. Set the shipping cost of flat rate to 5.95 per order
4. Assign shipping costs to the tax group 'taxable goods'
5. Set the tax amount to 21%
6. Create a cart rule that gives 1.50 discount per item
7. Set the following tax config settings:

INSERT INTO `core_config_data` (`config_id`, `scope`, `scope_id`, `path`, `value`)
VALUES
	(88, 'default', 0, 'tax/classes/shipping_tax_class', '2'),
	(89, 'default', 0, 'tax/calculation/cross_border_trade_enabled', '0'),
	(90, 'default', 0, 'tax/defaults/postcode', NULL),
	(91, 'default', 0, 'tax/calculation/algorithm', 'TOTAL_BASE_CALCULATION'),
	(92, 'default', 0, 'tax/calculation/based_on', 'origin'),
	(93, 'default', 0, 'tax/notification/ignore_discount', '0'),
	(94, 'default', 0, 'tax/notification/ignore_price_display', '0'),
	(95, 'default', 0, 'tax/notification/ignore_apply_discount', '0'),
	(96, 'default', 0, 'tax/calculation/price_includes_tax', '1'),
	(97, 'default', 0, 'tax/calculation/shipping_includes_tax', '1'),
	(98, 'default', 0, 'tax/calculation/apply_after_discount', '1'),
	(99, 'default', 0, 'tax/calculation/discount_tax', '1'),
	(100, 'default', 0, 'tax/calculation/apply_tax_on', '0'),
	(101, 'default', 0, 'tax/defaults/country', 'NL'),
	(102, 'default', 0, 'tax/defaults/region', '0'),
	(103, 'default', 0, 'tax/display/type', '2'),
	(104, 'default', 0, 'tax/display/shipping', '2'),
	(105, 'default', 0, 'tax/cart_display/price', '2'),
	(106, 'default', 0, 'tax/cart_display/subtotal', '2'),
	(107, 'default', 0, 'tax/cart_display/shipping', '2'),
	(108, 'default', 0, 'tax/cart_display/grandtotal', '0'),
	(109, 'default', 0, 'tax/cart_display/full_summary', '0'),
	(110, 'default', 0, 'tax/cart_display/zero_tax', '1'),
	(111, 'default', 0, 'tax/sales_display/price', '2'),
	(112, 'default', 0, 'tax/sales_display/subtotal', '2'),
	(113, 'default', 0, 'tax/sales_display/shipping', '2'),
	(114, 'default', 0, 'tax/sales_display/grandtotal', '0'),
	(115, 'default', 0, 'tax/sales_display/full_summary', '0'),
	(116, 'default', 0, 'tax/sales_display/zero_tax', '1');
INSERT INTO `core_config_data` (`config_id`, `scope`, `scope_id`, `path`, `value`)
VALUES
	(117, 'default', 0, 'shipping/origin/country_id', 'NL'),
	(118, 'default', 0, 'shipping/origin/region_id', NULL),
	(119, 'default', 0, 'shipping/origin/postcode', NULL),
	(120, 'default', 0, 'shipping/origin/city', NULL),
	(121, 'default', 0, 'shipping/origin/street_line1', NULL),
	(122, 'default', 0, 'shipping/origin/street_line2', NULL);
INSERT INTO `core_config_data` (`config_id`, `scope`, `scope_id`, `path`, `value`)
VALUES
	(8, 'default', 0, 'currency/options/base', 'EUR'),
	(9, 'default', 0, 'currency/options/default', 'EUR'),
	(10, 'default', 0, 'currency/options/allow', 'EUR');

Steps to reproduce

1. Buy the product of 5.99 with a quantity of 10
2. Go to the cart. Verify that the subtotal is €59.90, the discount is -€15.00
3. Click 'estimate shipping and tax' in the cart summary
4. Pick the shipping method of €5.95. I had to select Netherlands as country.
5. Verify that the shipping total is €5.95 and the tax total is €8.65
6. Verify that the order total is €49.85
7. Place the order
8. Create an invoice
9. SELECT order_id, grand_total, base_grand_total from sales_invoice WHERE order_id=5;

Expected result

1. This outcome:

order_id	grand_total	base_grand_total
5	50.8500	50.8500

Actual result

1. This outcome

order_id	grand_total	base_grand_total
5	50.8500	50.8600

The base_grand_total is one cent too high.

[AlexWorking]

Hello @ajpevers. I've been trying to reproduce this issue, but something seem to not stick with the preconditions and the steps to reproduce. After I fulfilled 6 steps of the preconditions the 7-th step is not executable. Some records can not be inserted due to duplicating entries on some keys. Also, please specify the 4-th and the 5-th steps of preconditions in more details.

[AntonEvers]

Hello @AlexWorking

m2community_2017-08-04.sql.gz

I have attached a dump of fresh install with the config that was necessary. If you will look at the only invoice that is placed in the shop, you will see that the grand_total and the base_grand_total differ.

You can place new orders with this database dump in place and verify that this happens in the develop branch.

Basically the steps can now be simplified to:

1. import the db dump and change the url keys etc to make it work (also create an admin account for yourself)
2. place an order of 10 products
3. create an invoice from the admin

[AntonEvers]

Adding to this that the shipping_discount_tax_compensation_amount is -0.0100 and the base_shipping_discount_tax_compensation_amount is NULL

[AntonEvers]

@AlexWorking found the bug. Fixed it.

[magento-team]

Internal ticket to track issue progress: MAGETWO-71360