[Forward Port] magento/magento2#12205: Stock inventory reindex bug.

[hostep]

(cherry picked from commit 20d7afb)

Description (*)

This is a forward port of https://github.com/magento-engcom/magento2ce/pull/1134 to Magento 2.3-develop (since this is a non-public PR, I can't see the discussion in there unfortunately)
It looks like this fix got included in Magento 2.2.5, but was forgotten to be forward ported to Magento 2.3

Fixed Issues (if relevant)

1. Stock inventory reindex bug #12205: Stock inventory reindex bug
2. Random products show out of stock until manual reindex #15984: Random products show out of stock until manual reindex

Manual testing scenarios (*)

1. Setup vanilla 2.3-develop installation including sample data
2. Run bin/magento indexer:set-mode schedule
3. In the frontend of the shop, go to Gear > Bags. Notice there are 14 products visible here => good
4. Execute the following SQL query which will simulate that 1891 products stock data was updated and schedules them for reindexing: INSERT INTO cataloginventory_stock_cl(entity_id) SELECT a.entity_id FROM catalog_product_entity a INNER JOIN cataloginventory_stock_status b ON a.entity_id=b.product_id AND b.website_id=0 WHERE a.type_id='simple'
5. Run bin/magento indexer:status to verify this
6. If you have magerun2 installed, run: php n98-magerun2.phar sys:cron:run indexer_update_all_views, otherwise run bin/magento cron:run
7. Run bin/magento indexer:status to verify that all scheduled updates were processed
8. In the frontend of the shop, go to Gear > Bags. Notice there are 0 products visible here => not good
9. Notice the amount of entries in the cataloginventory_stock_status database table, there are 1046 in here
10. Now perform a manual full reindex of the stock: bin/magento indexer:reindex cataloginventory_stock
11. In the frontend of the shop, go to Gear > Bags. Notice there are 14 products visible here => good
12. Notice the amount of entries in the cataloginventory_stock_status database table, there are 2046 in here

Now repeat the same but with this PR applied, and you'll notice that in step 8 and 9 the correct thing happens and further steps are no longer needed

Questions or comments

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 are green)

[m2-assistant]

Hi @hostep. 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 give me test instance - deploy test instance based on PR changes
• @magento give me 2.3-develop instance - deploy vanilla Magento instance

For more details, please, review the Magento Contributor Guide documentation.

[kalpmehta]

Thanks @hostep for the contribution!
FYI I see the patch here https://raw.githubusercontent.com/ConvertGroupsAS/magento2-patches/master/Patch-Magento_CatalogInventory-M2.2.0-2.2.4-stock-index.patch

[magento-engcom-team]

Hi @kalpmehta, thank you for the review.
ENGCOM-6188 has been created to process this Pull Request
✳️ @kalpmehta, could you please add one of the following labels to the Pull Request?

Label	Description
Auto-Tests: Covered	All changes in Pull Request is covered by auto-tests
Auto-Tests: Not Covered	Changes in Pull Request requires coverage by auto-tests
Auto-Tests: Not Required	Changes in Pull Request does not require coverage by auto-tests

[engcom-Alfa]

✔️ QA Passed

[m2-assistant]

Hi @hostep, thank you for your contribution!
Please, complete Contribution Survey, it will take less than a minute.
Your feedback will help us to improve contribution process.