MultiFilter raises StopIteration

[shroom00]

MultiFilter raises StopIteration if there are no tokens to filter. Added a check for this case and returned an empty token list.

Description

• relevant motivation: I ran into this error when parsing queries (that should've been null queries) with a custom tokeniser.
• a summary of the change: See above.
• which issue is fixed: N/A
• any additional dependencies that are required for this change: N/A

Checklist:

• I have performed a self-review of my own code
• I have commented my code in hard-to-understand areas
• I have made corresponding changes to the documentation

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[github-actions]

This PR is stale because it has been 60 days with no activity. This PR will be automatically closed within 7 days if there is no further activity.

[github-actions]

This PR was closed because it has been stalled for some time with no activity.

[chitochi]

Hello !

I had the same problem using Whoosh, I think it would be nice to merge this PR.