Fix too many documents collected when only bool-filter condition is present (#14757)

Author: kkewwei

lucene/CHANGES.txt

@@ -57,6 +57,8 @@ Bug Fixes
   returns a string which can be parsed back into the original node.
   (Peter Barna, Adam Schwartz)
 
+* GITHUB#14755: Fix too many documents collected when only bool-filter condition is present. (Ke Wei)
+
 Changes in Runtime Behavior
 ---------------------
 * GITHUB#14187: The query cache is now disabled by default. (Adrien Grand)

lucene/core/src/java/org/apache/lucene/search/BooleanScorerSupplier.java

@@ -439,6 +439,13 @@ public float getMaxScore(int upTo) throws IOException {
       required.addAll(requiredScoring);
       required.addAll(requiredNoScoring);
       conjunctionScorer = new ConjunctionScorer(required, requiredScoring);
+      if (this.scoreMode == ScoreMode.TOP_SCORES && requiredScoring.size() == 0) {
+        conjunctionScorer =
+            conjunctionScorer.twoPhaseIterator() != null
+                ? new ConstantScoreScorer(
+                    0.0F, this.scoreMode, conjunctionScorer.twoPhaseIterator())
+                : new ConstantScoreScorer(0.0F, this.scoreMode, conjunctionScorer.iterator());
+      }
     }
     return new DefaultBulkScorer(conjunctionScorer);
   }

lucene/core/src/test/org/apache/lucene/search/TestBooleanScorer.java

@@ -24,7 +24,10 @@
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.Field.Store;
+import org.apache.lucene.document.FieldType;
+import org.apache.lucene.document.LongPoint;
 import org.apache.lucene.document.StringField;
+import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.Term;
@@ -402,4 +405,40 @@ public void testFilterConstantScore() throws Exception {
     w.close();
     dir.close();
   }
+
+  public void testCollectNoThresholdWhenOnlyFilter() throws Exception {
+    Directory dir = newDirectory();
+    RandomIndexWriter w = new RandomIndexWriter(random(), dir);
+    FieldType fieldType = new FieldType();
+    fieldType.setIndexOptions(IndexOptions.DOCS);
+    for (int i = 0; i < 50; i++) {
+      Document doc = new Document();
+      doc.add(new Field("foo", "bar" + (i % 2), fieldType));
+      doc.add(new LongPoint("field", i % 4));
+      w.addDocument(doc);
+    }
+
+    IndexReader reader = w.getReader();
+    IndexSearcher searcher = new IndexSearcher(reader);
+    searcher.setQueryCache(null);
+
+    TermQuery termQuery = new TermQuery(new Term("foo", "bar0"));
+
+    BooleanQuery.Builder builder = new BooleanQuery.Builder();
+    builder.add(termQuery, BooleanClause.Occur.FILTER);
+
+    Query indexQuery = LongPoint.newRangeQuery("field", 1, Long.MAX_VALUE);
+    builder.add(indexQuery, BooleanClause.Occur.FILTER);
+
+    int totalHitsThreshold = 7;
+    TopScoreDocCollectorManager topScoreDocCollectorManager =
+        new TopScoreDocCollectorManager(3, null, totalHitsThreshold);
+    TopScoreDocCollector collector = topScoreDocCollectorManager.newCollector();
+    searcher.search(builder.build(), collector);
+    assertEquals(totalHitsThreshold + 1, collector.totalHits);
+
+    reader.close();
+    w.close();
+    dir.close();
+  }
 }