Bugfix - BitmapIndexQuery and BitmapDocValuesQuery to support negative values

server/src/main/java/org/opensearch/search/query/BitmapDocValuesQuery.java

@@ -51,7 +51,7 @@ public BitmapDocValuesQuery(String field, RoaringBitmap bitmap) {
         this.bitmap = bitmap;
         if (!bitmap.isEmpty()) {
             min = bitmap.first();
-            max = bitmap.last();
+            max = Integer.toUnsignedLong(bitmap.last());
         } else {
             min = 0; // final field
             max = 0;
@@ -71,6 +71,11 @@ public ScorerSupplier scorerSupplier(LeafReaderContext context) throws IOExcepti
                         @Override
                         public boolean matches() throws IOException {
                             long value = singleton.longValue();
+                            // Check if negative
+                            if (value < 0) {
+                                // add 2^32 to make it unsigned
+                                value = (1L << 32) + value;
+                            }
                             return value >= min && value <= max && bitmap.contains((int) value);
                         }
 

server/src/main/java/org/opensearch/search/query/BitmapIndexQuery.java

@@ -31,6 +31,7 @@
 import org.apache.lucene.util.RamUsageEstimator;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Objects;
 
 import org.roaringbitmap.PeekableIntIterator;
@@ -71,7 +72,7 @@ interface BitmapIterator extends BytesRefIterator {
 
     private static BitmapIterator bitmapEncodedIterator(RoaringBitmap bitmap) {
         return new BitmapIterator() {
-            private final PeekableIntIterator iterator = bitmap.getIntIterator();
+            private final PeekableIntIterator iterator = bitmap.getSignedIntIterator();
             private final BytesRef encoded = new BytesRef(new byte[Integer.BYTES]);
 
             public BytesRef next() {

server/src/test/java/org/opensearch/search/query/BitmapDocValuesQueryTests.java

@@ -114,4 +114,48 @@ public void testScoreMutilValues() throws IOException {
         Set<Integer> expected = Set.of(2, 3);
         assertEquals(expected, actual);
     }
+
+    public void testScoreWithNegatives() throws IOException {
+        Document d = new Document();
+        d.add(new IntField("product_id", 1, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", 2, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", 3, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", 4, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", -2, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", -3, Field.Store.NO));
+        w.addDocument(d);
+
+        w.commit();
+        reader = DirectoryReader.open(w);
+        searcher = newSearcher(reader);
+
+        RoaringBitmap bitmap = new RoaringBitmap();
+        bitmap.add(1);
+        bitmap.add(-2);
+        bitmap.add(4);
+        bitmap.add(-3);
+        bitmap.add(2);
+        BitmapDocValuesQuery query = new BitmapDocValuesQuery("product_id", bitmap);
+
+        Weight weight = searcher.createWeight(searcher.rewrite(query), ScoreMode.COMPLETE_NO_SCORES, 1f);
+
+        List<Integer> actual = getMatchingValues(weight, searcher.getIndexReader());
+        List<Integer> expected = List.of(1, 2, 4, -2, -3);
+        assertEquals(expected, actual);
+    }
 }

server/src/test/java/org/opensearch/search/query/BitmapIndexQueryTests.java

@@ -280,4 +280,53 @@ public void testPointVisitor() throws IOException {
         Set<Integer> expected = Set.of(1, 2, 3);
         assertEquals(expected, actual);
     }
+
+    public void testScoreWithNegatives() throws IOException {
+        Document d = new Document();
+        d.add(new IntField("product_id", 1, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", 2, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", 3, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", 4, Field.Store.NO));
+        w.addDocument(d);
+
+        // Add negative product_ids as they are technically valid integer values
+        d = new Document();
+        d.add(new IntField("product_id", -2, Field.Store.NO));
+        w.addDocument(d);
+
+        d = new Document();
+        d.add(new IntField("product_id", -3, Field.Store.NO));
+        w.addDocument(d);
+
+        w.commit();
+        reader = DirectoryReader.open(w);
+        searcher = newSearcher(reader);
+
+        RoaringBitmap bitmap = new RoaringBitmap();
+        bitmap.add(1);
+        bitmap.add(4);
+        bitmap.add(-2);
+        bitmap.add(2);
+        bitmap.add(-3);
+        bitmap.add(3);
+
+        BitmapIndexQuery query = new BitmapIndexQuery("product_id", bitmap);
+
+        Weight weight = searcher.createWeight(searcher.rewrite(query), ScoreMode.COMPLETE_NO_SCORES, 1f);
+
+        List<Integer> actual = getMatchingValues(weight, searcher.getIndexReader());
+        // Has to be sorted. Negative values are greater than Positive as 2^32 is added to negative numbers when
+        // converting signed int to unsigned int
+        List<Integer> expected = List.of(1, 2, 3, 4, -2, -3);
+        assertEquals(expected, actual);
+    }
 }