Handle client level header size validation response before sending to…

… server

ballerina-tests/http2-tests/tests/http2_configuration_request_limit_config_test.bal

@@ -147,7 +147,7 @@ function testHttp2ValidHeaderLength() returns error? {
 //Tests the behaviour when header size is greater than the configured threshold
 // TODO: Enable after fixing this issue : https://github.com/ballerina-platform/ballerina-standard-library/issues/3963
 @test:Config {
-    enable: false
+    enable: true
 }
 function testHttp2InvalidHeaderLength() returns error? {
     http:Client limitClient = check new ("http://localhost:" + http2RequestLimitsTestPort3.toString(),

native/src/main/java/io/ballerina/stdlib/http/transport/contractimpl/common/states/Http2StateUtil.java

@@ -43,6 +43,7 @@
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPromise;
 import io.netty.handler.codec.http.DefaultLastHttpContent;
 import io.netty.handler.codec.http.HttpContent;
 import io.netty.handler.codec.http.HttpHeaderNames;
@@ -320,9 +321,13 @@ public static void writeHttp2Headers(ChannelHandlerContext ctx, OutboundMsgHolde
                 return;
             }
         }
-
-        encoder.writeHeaders(ctx, streamId, http2Headers, dependencyId, weight, false, 0, endStream,
-                             ctx.newPromise());
+        ChannelPromise promise = ctx.newPromise();
+        encoder.writeHeaders(ctx, streamId, http2Headers, dependencyId, weight, false, 0, endStream, promise);
+        promise.addListener((ChannelFutureListener) channelFuture -> {
+            if (!channelFuture.isSuccess()) {
+                outboundMsgHolder.getResponseFuture().notifyHttpListener(channelFuture.cause());
+            }
+        });
         encoder.flowController().writePendingBytes();
         ctx.flush();