[LUCENE-4935] CustomScoreQuery has broken boosting

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.3.1, 6.0
• Component/s: core/query/scoring
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Robert Muir
• Created: 15/Apr/13 21:55
• Updated: 28/Aug/22 13:44
• Resolved: 17/Apr/13 15:03

Description

CustomScoreQuery wrongly applies boost^2 instead of boost.

It wrongly incorporates its boost into the normalization factor passed down to subquery (like booleanquery does) and also multiplies it directly in its scorer.

The only reason the test passes today is because it compares raw score magnitudes when querynorm is on, which normalizes this away.

Changing the test to use newSearcher() demonstrates the brokenness.