[LUCENE-6042] CustomScoreQuery Explain differs from the actual score when topLevelBoost is used.

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 4.8
• Fix Version/s: 4.10.3, 5.0, 6.0
• Component/s: core/query/scoring
• Lucene Fields: New
• Assignee: Robert Muir
• Reporter: Denis Lantsman
• Created: 31/Oct/14 23:21
• Updated: 28/Aug/22 14:19
• Resolved: 01/Dec/14 03:27

Description

CustomScoreQuery.java, doExplain has the following line:

res.addDetail(new Explanation(getBoost(), "queryBoost"));

This multiplies the custom score query by just the boost of the current query, and not by

queryWeight=topLevelBoost*getBoost();

which is the value that's actually used during scoring. This leads to drastically different scores in the debug info, relative to the actual score, when the query is a subquery of another one, like a BooleanQuery clause, with a non-1 boost.