Fix not detecting current store using store code in url using $storeResolver->getCurrentStoreId()

[mimarcel]

Description

Current store id is not correctly identified when $storeResolver->getCurrentStoreId() is used.
$storeManager->getStore()->getId() should be used instead.

Fixed Issues

1. The country drop-down list display incorrect after upgrade to 2.1.4 in Admin #8732: The country drop-down list display incorrect after upgrade to 2.1.4 in Admin

Manual testing scenarios

PRE-REQUISTIES:

1. Set STORES -> Configuration -> GENERAL -> Web -> Url Options -> Add Store Codes to Urls to Yes.
2. The system has at least two websites.

• The first website is set as default website
• The first website has a store view with code default
• The second website has a store view with code storeview2.
  

3. Set STORES -> Configuration -> GENERAL -> General -> Country Options -> Allow Countries to Estonia for first website.
4. Set STORES -> Configuration -> GENERAL -> General -> Country Options -> Allow Countries to Romania for second website.

STESP TO REPLICATE

1. Access the website directly using storeview2 store code, e.g. http://local-magento2/storeview2/
2. Add any product to cart
3. Go to checkout

EXPECTED

Available country for checkout: Romania

ACTUAL

Available country for checkout: Estonia

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-cicd2]

All committers have signed the CLA.

[hostep]

We just were hit by this bug by upgrading a store from Magento 2.1.5 to 2.1.6, but at yet another place.

Namely in the layered navigation. In version 2.1.6 Magento added some extra caching for the layered navigation select attributes, and they also use the super buggy StoreResolver::getCurrentStoreId() method, which doesn't do its job at all, because it always returns the default store id instead of the one on which you are browsing.
See here: https://github.com/magento/magento2/blob/2.1.6/app/code/Magento/Eav/Model/Entity/Attribute/Frontend/AbstractFrontend.php#L255
This was added in this commit: 67b5ff7

Replacing that with $this->storeManager->getStore()->getId() like is done in this PR, resolves the issue.

I think the real solution is to make sure the StoreResolver::getCurrentStoreId() does it job like it is supposed to do, instead of replacing it all over the codebase, but maybe that will cause new issues...

Tnx for the PR @mimarcel, saved me a lot of time and debugging!

[mimarcel]

@hostep It's indeed confusing that getCurrentStoreId does not return the final store id. However, the class name is called StoreResolver, therefore it's responsible for resolving the current store id. The StoreManager class is responsible for managing the current store id. The StoreManager uses theStoreResolver, but the current store id can be overwritten by other logic as well by calling setCurrentStore. This is quite tricky since it seems that the issue does replicate in more than one place; it seems it's not really easy to catch even for developers from Magento.

Glad this solution was useful to someone!

[hostep]

Ok I think this makes sense, thanks for the clarification!
I'll try to create a PR for the Magento 2.1.6 issue we encountered today (maybe tonight, maybe in one of the coming days).

[ishakhsuvarov]

Unfortunately, due to backwards compatibility policy we may not change constructor arguments. Please add another optional dependency and deprecate the old one if it is not used anymore.