Fix BasicLoadBalancingPolicy.getReplica empty partitioner

core/src/main/java/com/datastax/oss/driver/api/core/metadata/TokenMap.java

@@ -189,4 +189,8 @@ default Set<Node> getReplicas(@NonNull String keyspaceName, @NonNull TokenRange
   /** The name of the partitioner class in use, as reported by the Cassandra nodes. */
   @NonNull
   String getPartitionerName();
+
+  /** The partitioner class in use, as reported by the Cassandra nodes. */
+  @NonNull
+  Partitioner getPartitioner();
 }

core/src/main/java/com/datastax/oss/driver/internal/core/loadbalancing/BasicLoadBalancingPolicy.java

@@ -333,6 +333,9 @@ protected Set<Node> getReplicas(@Nullable Request request, @Nullable Session ses
       }
 
       partitioner = request.getPartitioner();
+      if (partitioner == null && maybeTokenMap.isPresent()) {
+        partitioner = maybeTokenMap.get().getPartitioner();
+      }
     } catch (Exception e) {
       // Protect against poorly-implemented Request instances
       LOG.error("Unexpected error while trying to compute query plan", e);

core/src/main/java/com/datastax/oss/driver/internal/core/metadata/token/DefaultTokenMap.java

@@ -207,6 +207,12 @@ public String getPartitionerName() {
     return tokenFactory.getPartitionerName();
   }
 
+  @NonNull
+  @Override
+  public Partitioner getPartitioner() {
+    return tokenFactory;
+  }
+
   private KeyspaceTokenMap getKeyspaceMap(CqlIdentifier keyspace) {
     Map<String, String> config = replicationConfigs.get(keyspace);
     return (config == null) ? null : keyspaceMaps.get(config);