fix: correct OR null handling for BlockList|BlockList

rust/lance-core/src/utils/mask/nullable.rs

@@ -251,15 +251,17 @@ impl std::ops::BitOr for NullableRowAddrMask {
                 Self::BlockList(NullableRowAddrSet { selected, nulls })
             }
             (Self::BlockList(a), Self::BlockList(b)) => {
+                let a_false = a.selected.clone() - &a.nulls;
+                let b_false = b.selected.clone() - &b.nulls;
                 let nulls = if a.nulls.is_empty() && b.nulls.is_empty() {
                     RowAddrTreeMap::new() // Fast path
                 } else {
-                    // null or null -> null (excluding rows that are true in either)
-                    let false_rows =
-                        (a.selected.clone() - &a.nulls) & (b.selected.clone() - &b.nulls);
-                    (a.nulls | &b.nulls) - false_rows
+                    // NULL if: (A NULL & B FALSE) or (A FALSE & B NULL) or (A NULL & B NULL).
+                    (a.nulls.clone() & &b_false)
+                        | (b.nulls.clone() & &a_false)
+                        | (a.nulls & &b.nulls)
                 };
-                let selected = (a.selected & b.selected) | &nulls;
+                let selected = (a_false & b_false) | &nulls;
                 Self::BlockList(NullableRowAddrSet { selected, nulls })
             }
         }
@@ -390,6 +392,17 @@ mod tests {
         assert_mask_selects(&result, &[2], &[0, 1]);
     }
 
+    #[test]
+    fn test_or_block_block_true_overrides_null() {
+        // TRUE OR NULL should be TRUE, even when both sides are BlockList.
+        let true_mask = block(&[], &[]);
+        let null_mask = block(&[], &[0]);
+        let result = true_mask | null_mask;
+
+        // Row 0 should be TRUE.
+        assert_mask_selects(&result, &[0], &[]);
+    }
+
     #[test]
     fn test_row_selection_bit_or() {
         // [T, N, T, N, F, F, F]

rust/lance/tests/query/primitives.rs

@@ -81,6 +81,18 @@ async fn test_query_integer(#[case] data_type: DataType) {
             test_filter(&original, &ds, "value is not null").await;
             test_filter(&original, &ds, "(value != 0) OR (value < 20)").await;
             test_filter(&original, &ds, "NOT ((value != 0) OR (value < 20))").await;
+            test_filter(
+                &original,
+                &ds,
+                "(value != 5) OR ((value != 52) OR (value IS NULL))",
+            )
+            .await;
+            test_filter(
+                &original,
+                &ds,
+                "NOT ((value != 5) OR ((value != 52) OR (value IS NULL)))",
+            )
+            .await;
         })
         .await
 }