From 56084a7cc852b2d8b428aa5619b681180b2874d0 Mon Sep 17 00:00:00 2001
From: Xiang Li <xiangli.cs@gmail.com>
Date: Tue, 13 Sep 2016 11:18:21 +0800
Subject: [PATCH] clientv3: return error from response when possible

---
 clientv3/concurrency/key.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/clientv3/concurrency/key.go b/clientv3/concurrency/key.go
index 74d495dd066..56172bd0851 100644
--- a/clientv3/concurrency/key.go
+++ b/clientv3/concurrency/key.go
@@ -26,14 +26,20 @@ import (
 func waitDelete(ctx context.Context, client *v3.Client, key string, rev int64) error {
 	cctx, cancel := context.WithCancel(ctx)
 	defer cancel()
+
+	var wr v3.WatchResponse
 	wch := client.Watch(cctx, key, v3.WithRev(rev))
-	for wr := range wch {
+	for wr = range wch {
 		for _, ev := range wr.Events {
 			if ev.Type == mvccpb.DELETE {
 				return nil
 			}
 		}
 	}
+	if err := wr.Err(); err != nil {
+		return err
+	}
+
 	if err := ctx.Err(); err != nil {
 		return err
 	}