Fixed comparison with 0 bug for TableRate shipping carrier

[irs]

Description

In free shipping flow sometimes you can get such query to DB:

SQL: SELECT `shipping_tablerate`.* FROM `shipping_tablerate` WHERE ...
BIND: array (
':website_id' => 1,
':country_id' => 'US',
':region_id' => 12,
':postcode' => '68138',
':condition_name' => 'package_value',
':condition_value' => -3.5527136788005009E-15,
)
AFF: 0

It leads to disabled TabelRate shipping method. Such value is calculated in Magento\OfflineShipping\Model\Carrier\Tablerate::collectRates(). Smth like:

29.95 - 10 - 19 - .95 = -3.5527136788005009E-15

and normally should be rounded before comparison. See http://php.net/manual/en/language.types.float.php

Manual testing scenarios

1. Setup free shipping rule with Subtotal >= 25.
2. Setup TableRate shippign method.
3. Add products to cart.
4. Apply free shipping coupon.
5. TableRate shippign method disappears.

[magento-cicd2]

All committers have signed the CLA.

[miguelbalparda]

Thanks for the submission @irs! Have you seen any reports of this?

[irs]

@miguelbalparda no, but I did not search a lot.

[magento-engcom-team]

@irs thank you for contributing. Please accept Community Contributors team invitation here to gain extended permissions for this repository.

[sidolov]

Hi @irs , consider porting this solution to other Magento versions.
Recently our team introduced a simple way to port fixes across versions, details available here