From 329c5767a505ee29e0c9615bb53a4114d59853ef Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Wed, 12 May 2021 15:35:38 -0400
Subject: [PATCH 1/2] fix: check clusterTime is defined before access

---
 lib/core/wireprotocol/command.js | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/lib/core/wireprotocol/command.js b/lib/core/wireprotocol/command.js
index fd581c84f4..378fe3e93c 100644
--- a/lib/core/wireprotocol/command.js
+++ b/lib/core/wireprotocol/command.js
@@ -45,14 +45,20 @@ function _command(server, ns, cmd, options, callback) {
   const shouldUseOpMsg = supportsOpMsg(server);
   const session = options.session;
 
-  let clusterTime = server.clusterTime;
+  const serverClusterTime = server.clusterTime;
+  let clusterTime = serverClusterTime;
   let finalCmd = Object.assign({}, cmd);
   if (hasSessionSupport(server) && session) {
+    const sessionClusterTime = session.clusterTime;
     if (
-      session.clusterTime &&
-      session.clusterTime.clusterTime.greaterThan(clusterTime.clusterTime)
+      serverClusterTime &&
+      serverClusterTime.clusterTime &&
+      sessionClusterTime &&
+      sessionClusterTime.clusterTime
     ) {
-      clusterTime = session.clusterTime;
+      if (sessionClusterTime.clusterTime.greaterThan(serverClusterTime.clusterTime)) {
+        clusterTime = sessionClusterTime;
+      }
     }
 
     const err = applySession(session, finalCmd, options);
@@ -61,8 +67,8 @@ function _command(server, ns, cmd, options, callback) {
     }
   }
 
-  // if we have a known cluster time, gossip it
   if (clusterTime) {
+    // if we have a known cluster time, gossip it
     finalCmd.$clusterTime = clusterTime;
   }
 

From 92f424996a544ddce4e50d2ea5216e1ff0e1cec4 Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Mon, 17 May 2021 15:20:51 -0400
Subject: [PATCH 2/2] fix: collapse if stmt

---
 lib/core/wireprotocol/command.js | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/core/wireprotocol/command.js b/lib/core/wireprotocol/command.js
index 378fe3e93c..9e687f8c95 100644
--- a/lib/core/wireprotocol/command.js
+++ b/lib/core/wireprotocol/command.js
@@ -54,11 +54,10 @@ function _command(server, ns, cmd, options, callback) {
       serverClusterTime &&
       serverClusterTime.clusterTime &&
       sessionClusterTime &&
-      sessionClusterTime.clusterTime
+      sessionClusterTime.clusterTime &&
+      sessionClusterTime.clusterTime.greaterThan(serverClusterTime.clusterTime)
     ) {
-      if (sessionClusterTime.clusterTime.greaterThan(serverClusterTime.clusterTime)) {
-        clusterTime = sessionClusterTime;
-      }
+      clusterTime = sessionClusterTime;
     }
 
     const err = applySession(session, finalCmd, options);