[LUCENE-991] BoostingTermQuery.explain() bugs

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.2
• Component/s: core/search
• Lucene Fields: Patch Available
• Assignee: Grant Ingersoll
• Reporter: Peter Keegan
• Created: 31/Aug/07 14:35
• Updated: 28/Aug/22 11:40
• Resolved: 08/Sep/07 16:57

Description

There are a couple of minor bugs in BoostingTermQuery.explain().

1. The computation of average payload score produces NaN if no payloads were found. It should probably be:
float avgPayloadScore = super.score() * (payloadsSeen > 0 ? (payloadScore / payloadsSeen) : 1);

2. If the average payload score is zero, the value of the explanation is 0:
result.setValue(nonPayloadExpl.getValue() * avgPayloadScore);
If the query is part of a BooleanClause, this results in:
"no match on required clause..."
"failure to meet condition(s) of required/prohibited clause(s)"

The average payload score can be zero if the field boost = 0.

I've attached a patch to 'TestBoostingTermQuery.java', however, the test 'testNoPayload' fails in 'SpanScorer.score()' because the doc = -1. It looks like 'setFreqCurrentDoc() should have been called before 'score()'. Maybe someone more knowledgable of spans could investigate this.