From e4df5f4f102231dea2054fae3b9fe7bbbf256c20 Mon Sep 17 00:00:00 2001
From: Matt Broadstone <mbroadst@mongodb.com>
Date: Wed, 18 Dec 2019 18:13:14 -0500
Subject: [PATCH] fix: not all message payloads are arrays of Buffer

---
 lib/cmap/message_stream.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/cmap/message_stream.js b/lib/cmap/message_stream.js
index 8bab9250f7..15a4c75a6a 100644
--- a/lib/cmap/message_stream.js
+++ b/lib/cmap/message_stream.js
@@ -76,7 +76,8 @@ class MessageStream extends Duplex {
     // TODO: agreed compressor should live in `StreamDescription`
     const shouldCompress = operationDescription && !!operationDescription.agreedCompressor;
     if (!shouldCompress || !canCompress(command)) {
-      this.push(Buffer.concat(command.toBin()));
+      const data = command.toBin();
+      this.push(Array.isArray(data) ? Buffer.concat(data) : data);
       return;
     }