Enforce reindexing when category is set to virtual.

[romainruaud]

This is a fix for #465

Enforce reindexing (if set to Update on Save) when switching a category from normal mode to virtual mode.

Nothing done for mview, since this is actually working properly (due to the SQL trigger).

[afoucret]

It seems there is a problem with this line :

$this->getIndexer()->reindexList($category->getPathIds());

$category->getPathIds()returns category ids and you reindex it using the product indexer. IMHO you don't reindex the products as expected.

[romainruaud]

Hmmm, this is the "catalog_category_product" indexer, and it's taking category ids for reindex : https://github.com/magento/magento2/blob/develop/app/code/Magento/Catalog/Model/Indexer/Category/Product/Action/Rows.php

This is done same way by Magento on standard category model (but only if there are products attached, which is not good in our case) : https://github.com/magento/magento2/blob/develop/app/code/Magento/Catalog/Model/Category.php#L1097

This is indexing properly the products in the catalog_category_product_index table (removing them, exactly), and then the fulltext indexer does the job and removes the "category" field from documents.

[romainruaud]

PR Updated :

• prevent reindexing of root category

• prevent reindexing if no products were attached previously (this manage the case of a virtual category creation, since its done in 2 steps).