From 2bccd3f017017378421581ed84179d11dc08c048 Mon Sep 17 00:00:00 2001
From: Matt Broadstone <mbroadst@mongodb.com>
Date: Wed, 17 Jul 2019 10:43:17 -0400
Subject: [PATCH] fix: don't check non-unified topologies for session support
 check

---
 lib/core/cursor.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/core/cursor.js b/lib/core/cursor.js
index a752213a32..646f89e39b 100644
--- a/lib/core/cursor.js
+++ b/lib/core/cursor.js
@@ -586,7 +586,7 @@ Cursor.prototype._initializeCursor = function(callback) {
   const cursor = this;
 
   // NOTE: this goes away once cursors use `executeOperation`
-  if (cursor.topology.shouldCheckForSessionSupport()) {
+  if (cursor.topology.description != null && cursor.topology.shouldCheckForSessionSupport()) {
     cursor.topology.selectServer(ReadPreference.primaryPreferred, err => {
       if (err) {
         callback(err);