[LUCENE-9524] NullPointerException in IndexSearcher.explain() when using ComplexPhraseQueryParser

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 8.6, 8.6.2
• Fix Version/s: 8.7
• Component/s: core/queryparser, core/search
• Assignee: Unassigned
• Reporter: Michał Słomkowski
• Created: 15/Sep/20 11:54
• Updated: 28/Aug/22 16:07
• Resolved: 16/Oct/20 17:23

Description

I get NPE when I use IndexSearcher.explain(). Checked with Lucene 8.6.0
and 8.6.2.

The query: (lorem AND NOT "dolor lorem") OR ipsum
The text: dolor lorem ipsum

Stack trace:

java.lang.NullPointerException at java.util.Objects.requireNonNull(Objects.java:203)
	at org.apache.lucene.search.LeafSimScorer.<init>(LeafSimScorer.java:38)
	at org.apache.lucene.search.spans.SpanWeight.explain(SpanWeight.java:160)
	at org.apache.lucene.search.BooleanWeight.explain(BooleanWeight.java:87)
	at org.apache.lucene.search.BooleanWeight.explain(BooleanWeight.java:87)
	at org.apache.lucene.search.IndexSearcher.explain(IndexSearcher.java:716)
	at org.apache.lucene.search.IndexSearcher.explain(IndexSearcher.java:693)

Minimal example code:

val analyzer = new StandardAnalyzer();
val query = new ComplexPhraseQueryParser("", analyzer).parse(queryString);

final MemoryIndex memoryIndex = new MemoryIndex(true);
memoryIndex.addField("", text, analyzer);

final IndexSearcher searcher = memoryIndex.createSearcher();
final TopDocs topDocs = searcher.search(query, 1);

final ScoreDoc match = topDocs.scoreDocs[0];

searcher.explain(query, match.doc);

Issue Links

• links to: GitHub Pull Request #1978