Re-indexing space kills full text search index in opensearch

[schweigisito]

Describe the bug

Full text search (FTS) doesn't work anymore once a re-index of a space has been triggered. Used search backend is opensearch in a opencloud k8s deployment.

Behaviour is not reproducible in a docker environment using "bleve".

Steps to reproduce

1. Create a file e.g. testfilereindexissue.txt with the conent Search string for testing: 30e589bce5dc36dce2c7aa1e239932f4
2. Save file
3. Search for 30e589bce5dc36dce2c7aa1e239932f4 within the OC WebUI search
   => Search result shows the created file
4. Execute curl command angainst the opensearch api:

curl -H 'Content-Type: application/json' -s http://opencloud-opensearch-cluster-master.opensearch.svc.cluster.local:9200/opencloud-resource/_search -d '{"query": {"query_string": {"query": "30e589bce5dc36dce2c7aa1e239932f4"}}}

=> opensearch api return the indexed entry

4. Run opencloud search index --all-spaces --force-rescan --insecure (on opencloud-api pod)
5. Search again via UI:

=> no search result

6. Execute curl command again

=> no result from opensearch api

7. Edit previously created test file by adding anything and save

=> file gets re-indexed and both UI and opensearch api correctly answer the search query

Expected behavior

FTS must not get broken after re-indexing

Actual behavior

See above

Setup

Standard OpenCloud helmfile deployment in k3s single node cluster with empty spaces but the single testfile.