Bug description:

When the partOf document contains several titles only the last one is indexed in the child document. See for example:

Le ski et ses frontières
Auteur: Busset, Thomas
Document hôte (partOf): Surmonter les frontières à ski
PID: 2079395

Expected behavior:

The full title: title._text is indexed in the child document.

Steps to Reproduce:

Steps to reproduce the problem:

1. Create a document with partOf field on a document containing multiple fields for title.
2. Check the search results: https://myserver.xx/api/documents/?q=pid:new_pid
3. The new document should contains the full parent title.

PRE:

1. Search for "surmonter busset ski" : only one result
2. Search "überwinden busset ski" : three results
3. Only the german part of the child document's title is indexed and gives the expected search results

Context

Server:

• production: bib.rero.ch or ils.bib.uclouvain.be
• test: bib.test.rero.ch
• dev: ilsdev.test.rero.ch
• dev test : ils.test.rero.ch

Version:

<=v1.9.0