When indexing fallback content using the search API there's an issue because the content ends up being indexed "incorrectly". By using solely the "Content (with language fallback)" datasource our indexed content will show itself with a wrong ID. This happens due to the logic implemented on the processor FallbackLanguage::alterIndexedItems. I've attached an image as a example on this.
1. Create a search index with the datasource Content (with language fallback).
2. Index your content.
3. Check the IDs of the indexed content.
Add a extra validation on the code (see patch)
Needs review
1.5
Code
Could be related to 🐛 View rendering multiple translations as the same translation (latest revised translation) RTBC .