[LUCENE-5455] Nested SpanNear queries lose positional highlights

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 4.3.1, 4.6.1
• Fix Version/s: 7.3
• Component/s: modules/highlighter
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Steve Davids
• Created: 19/Feb/14 13:21
• Updated: 28/Aug/22 14:00
• Resolved: 11/Jan/18 04:10

Description

Given text of: "x y z x z x a"
With a query of: spanNear([spanNear([text:x, text:y, text:z], 0, true), text:a], 10, false)
Resulting highlight: <B>x</B> <B>y</B> <B>z</B> <B>x</B> <B>z</B> <B>x</B> <B>a</B>
Expected highlight: <B>x</B> <B>y</B> <B>z</B> x z x <B>a</B>

This is caused because WeightedSpanTermExtractor.extractWeightedSpanTerms takes the SpanQuery and flattens all terms and uses the positions from the outermost SpanNear clause (ignoring the nested SpanNear positions). I believe this could be resolved with a little recursion - walking the span query tree in the extractWeightedSpanTerms method.

Issue Links

• duplicates: LUCENE-2287 Unexpected terms are highlighted within nested SpanQuery instances
• is duplicated by: LUCENE-8121 UnifiedHighlighter can highlight terms within SpanNear clauses at unmatched positions