[SOLR-11855] known field's empty value can vanish via add-unknown-fields-to-the-schema updateRequestProcessorChain

• Type: Bug
• Status: Open
• Priority: Trivial
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Christine Poerschke
• Created: 15/Jan/18 15:23
• Updated: 15/Jan/18 15:27

Description

known field's empty value can vanish via add-unknown-fields-to-the-schema updateRequestProcessorChain

This appears to be due to the "remove-blank" processor in the "add-unknown-fields-to-the-schema" process chain i.e. remove-blank applies to known as well as unknown fields (and when field guessing is disabled then remove-blank logic also stops).

Technically there's nothing broken here but I'm wondering if remove-blank might be removed (no pun intended) from the _default configuration or if the

WARNING: Using _default configset. Data driven schema functionality is enabled by default, which is NOT RECOMMENDED for production use.

To turn it off:            
curl http://localhost:8983/solr/collectionA/config -d '{"set-user-property": {"update.autoCreateFields":"false"}}'

wording might be revised somehow to better account for the remove-blank functionality?