Correctly handle multiple calls to DefaultHttp2StreamChannel.Unsafe.close(...)

Motivation:

Calling DefaultHttp2StreamChannel.Unsafe.close(...) multiple times should not fail.

Modification:

- Correctly handle multiple calls to DefaultHttp2StreamChannel.Unsafe.close(...)
- Complete closePromise and promise that is given to close(...) in the correct order.
- Add unit test

Result:

Fixes [#7628] and [#7641]

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java

@@ -32,7 +32,6 @@ import io.netty.channel.ChannelPromise;
 import io.netty.channel.DefaultChannelConfig;
 import io.netty.channel.DefaultChannelPipeline;
 import io.netty.channel.DefaultMaxMessagesRecvByteBufAllocator;
-import io.netty.channel.DelegatingChannelPromiseNotifier;
 import io.netty.channel.EventLoop;
 import io.netty.channel.MessageSizeEstimator;
 import io.netty.channel.RecvByteBufAllocator;
@@ -768,7 +767,7 @@ public class Http2MultiplexCodec extends Http2FrameCodec {
             @SuppressWarnings("deprecation")
             private RecvByteBufAllocator.ExtendedHandle recvHandle;
             private boolean writeDoneAndNoFlush;
-            private ChannelPromise pendingClosePromise;
+            private boolean closeInitiated;
 
             @Override
             public void connect(final SocketAddress remoteAddress,
@@ -831,27 +830,31 @@ public class Http2MultiplexCodec extends Http2FrameCodec {
 
             @Override
             public void disconnect(ChannelPromise promise) {
-                if (!promise.setUncancellable()) {
-                    return;
-                }
                 close(promise);
             }
 
             @Override
-            public void close(ChannelPromise promise) {
+            public void close(final ChannelPromise promise) {
                 if (!promise.setUncancellable()) {
                     return;
                 }
+                if (closeInitiated) {
                     if (closePromise.isDone()) {
-                    promise.setFailure(new ClosedChannelException());
+                        // Closed already.
+                        promise.setSuccess();
+                    } else if (!(promise instanceof VoidChannelPromise)) { // Only needed if no VoidChannelPromise.
+                        // This means close() was called before so we just register a listener and return
+                        closePromise.addListener(new ChannelFutureListener() {
+                            @Override
+                            public void operationComplete(ChannelFuture future) throws Exception {
+                                promise.setSuccess();
+                            }
+                        });
+                    }
                     return;
                 }
-                if (pendingClosePromise != null) {
-                    pendingClosePromise.addListener(new DelegatingChannelPromiseNotifier(promise));
-                    return;
-                }
-                pendingClosePromise = promise;
-                try {
+                closeInitiated = true;
+
                 closePending = false;
                 fireChannelReadPending = false;
 
@@ -874,16 +877,13 @@ public class Http2MultiplexCodec extends Http2FrameCodec {
                 }
 
                 // The promise should be notified before we call fireChannelInactive().
-                    promise.setSuccess();
                 closePromise.setSuccess();
+                promise.setSuccess();
 
                 pipeline().fireChannelInactive();
                 if (isRegistered()) {
                     deregister(unsafe().voidPromise());
                 }
-                } finally {
-                    pendingClosePromise = null;
-                }
             }
 
             @Override

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecTest.java

@@ -464,6 +464,18 @@ public class Http2MultiplexCodecTest {
         assertSame(headers, headers2);
     }
 
+    @Test
+    public void callUnsafeCloseMultipleTimes() {
+        LastInboundHandler inboundHandler = streamActiveAndWriteHeaders(inboundStream);
+        Http2StreamChannel childChannel = (Http2StreamChannel) inboundHandler.channel();
+        childChannel.unsafe().close(childChannel.voidPromise());
+
+        ChannelPromise promise = childChannel.newPromise();
+        childChannel.unsafe().close(promise);
+        promise.syncUninterruptibly();
+        childChannel.closeFuture().syncUninterruptibly();
+    }
+
     private LastInboundHandler streamActiveAndWriteHeaders(Http2FrameStream stream) {
         LastInboundHandler inboundHandler = new LastInboundHandler();
         childChannelInitializer.handler = inboundHandler;