From 3462a86a3ac41230965e3f06d527da6db9b39e04 Mon Sep 17 00:00:00 2001
From: Norman Maurer <norman_maurer@apple.com>
Date: Wed, 25 Jan 2017 12:51:06 +0100
Subject: [PATCH] Ensure we release the previous retained AddressedEnvelope
 when we fail to notify the promise.

Motivation:

We need to ensure we release the AddressedEnvelope if we fail to notify the future (as it may be notified before because of an timeout). Otherwise we may leak.

Modifications:

Call release() if we fail to notify the future.

Result:

No more memory leak on notify failure.
---
 .../src/main/java/io/netty/resolver/dns/DnsQueryContext.java | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/resolver-dns/src/main/java/io/netty/resolver/dns/DnsQueryContext.java b/resolver-dns/src/main/java/io/netty/resolver/dns/DnsQueryContext.java
index 6b98f36e8c..5439fb82b1 100644
--- a/resolver-dns/src/main/java/io/netty/resolver/dns/DnsQueryContext.java
+++ b/resolver-dns/src/main/java/io/netty/resolver/dns/DnsQueryContext.java
@@ -191,7 +191,10 @@ final class DnsQueryContext {
             @SuppressWarnings("unchecked")
             AddressedEnvelope<DnsResponse, InetSocketAddress> castResponse =
                     (AddressedEnvelope<DnsResponse, InetSocketAddress>) envelope.retain();
-            promise.setSuccess(castResponse);
+            if (!promise.trySuccess(castResponse)) {
+                // We failed to notify the promise as it was failed before, thus we need to release the envelope
+                envelope.release();
+            }
         }
     }