From 1b2c558e535229a39726aa3cf50aaf5498908ff3 Mon Sep 17 00:00:00 2001
From: murgatroid99 <mlumish@google.com>
Date: Tue, 1 Oct 2019 10:43:49 -0700
Subject: [PATCH] Copy outgoing metadata to avoid modifying it

---
 packages/grpc-js/src/channel.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/grpc-js/src/channel.ts b/packages/grpc-js/src/channel.ts
index e672072a..b2fdb654 100644
--- a/packages/grpc-js/src/channel.ts
+++ b/packages/grpc-js/src/channel.ts
@@ -277,7 +277,7 @@ export class ChannelImplementation implements Channel {
   }
 
   _startCallStream(stream: Http2CallStream, metadata: Metadata) {
-    this.tryPick(stream, metadata);
+    this.tryPick(stream, metadata.clone());
   }
 
   close() {