From 18869dcb08f34c853f797e83ae09b7ad89126cd4 Mon Sep 17 00:00:00 2001
From: murgatroid99 <mlumish@google.com>
Date: Fri, 21 Feb 2020 16:39:10 -0800
Subject: [PATCH] Clone metadata going into the metadata filter stack

---
 packages/grpc-js/package.json   | 2 +-
 packages/grpc-js/src/channel.ts | 7 ++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/packages/grpc-js/package.json b/packages/grpc-js/package.json
index d56999bc..52667831 100644
--- a/packages/grpc-js/package.json
+++ b/packages/grpc-js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@grpc/grpc-js",
-  "version": "0.6.17",
+  "version": "0.6.18",
   "description": "gRPC Library for Node - pure JS implementation",
   "homepage": "https://grpc.io/",
   "repository": "https://github.com/grpc/grpc-node/tree/master/packages/grpc-js",
diff --git a/packages/grpc-js/src/channel.ts b/packages/grpc-js/src/channel.ts
index e1db479c..8420b909 100644
--- a/packages/grpc-js/src/channel.ts
+++ b/packages/grpc-js/src/channel.ts
@@ -250,8 +250,11 @@ export class ChannelImplementation implements Channel {
             this.pickQueue.push({ callStream, callMetadata });
             break;
           }
+          /* We need to clone the callMetadata here because the transparent
+           * retry code in the promise resolution handler use the same
+           * callMetadata object, so it needs to stay unmodified */
           callStream.filterStack
-            .sendMetadata(Promise.resolve(callMetadata))
+            .sendMetadata(Promise.resolve(callMetadata.clone()))
             .then(
               finalMetadata => {
                 const subchannelState: ConnectivityState = pickResult.subchannel!.getConnectivityState();
@@ -280,6 +283,8 @@ export class ChannelImplementation implements Channel {
                       'channel',
                       'Failed to start call on picked subchannel ' +
                         pickResult.subchannel!.getAddress() +
+                        ' with error ' +
+                        (error as Error).message +
                         '. Retrying pick'
                     );
                     this.tryPick(callStream, callMetadata);