[2.2 develop] [backport #19018] [issue #17833] child theme does not inherit translations from parent theme

[vpodorozh]

Original pull request ( #19018 )

Description ( #17833 )

Child theme does not inherit translations from parent theme.
Theme inheritance does not work as expected with [translation dictionaries][1]. The child theme does not use any translations defined in it's parent theme's en_US.csv translation dictionary.

Fixed Issues

1. Child theme does not inherit translations from parent theme #17833: Child theme does not inherit translations from parent theme

Preconditions

I'm working on a Magento ver 2.2.5 installation with two websites & two corresponding theme's. Each with their own [translation dictionary][1], and one theme inheriting from the other.

Manual testing scenarios

1. Set up a magento instance with two websites and with two theme's, one inheriting from luma and the other inheriting from the other theme you created. See theme structure below.
2. Add a the translation string "Create New Customer Account","Create New Account" to the parent theme's en_US.csv translation dictionary.
3. Go to the /customer/account/create/ URL for the website with the child theme applied.

Expected result
The page title should be Create New Account

Actual result
The page title is still Create New Customer Account

• If go to the /customer/account/create/ URL for the website with the parent theme applied, the page title should is Create New Account. So the child theme is not picking up translations from the parent theme.
• If you add the translation string "Create New Customer Account","Create New Account" to the Child theme's en_US.csv translation dictionary you can see the translation string applied corectly on the website with the child theme applied.

Is this a bug with Magento or am I doing something wrong?

Is the [translation dictionary][1] documentation incorrect and this is actually the correct behaviour?

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-engcom-team]

Hi @vpodorozh. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

• @magento-engcom-team give me test instance - deploy test instance based on PR changes
• @magento-engcom-team give me $VERSION instance - deploy vanilla Magento instance

For more details, please, review the Magento Contributor Assistant documentation

[vadimjustus]

Hi @vpodorozh, please check the comments I've just added. There are just a few small changes requests :)

[vpodorozh]

Hi guys, I’ve found that in 2.2 develop branch unit test for Trsnslation.php is present and it does not pass - I’m going to take a look into it on Saturday.

[magento-engcom-team]

Hi @sivaschenko, thank you for the review.
ENGCOM-3527 has been created to process this Pull Request

[magento-engcom-team]

Hi @vpodorozh. Thank you for your contribution.
We will aim to release these changes as part of 2.2.8.
Please check the release notes for final confirmation.

Please, consider to port this solution to 2.3 release line.
You may use Porting tool to port commits automatically.