The Http2Settings max header list size setting is ignored by the conv…

…ersion to the actual Netty settings since we only send a setting when the new value is different from the initial value. The initial value is wrong and therefore leads to obtaining the incorrect value.

fixes #4211

src/main/java/io/vertx/core/http/Http2Settings.java

@@ -57,9 +57,9 @@ public class Http2Settings {
   public static final int DEFAULT_MAX_FRAME_SIZE = 16384;
 
   /**
-   * Default HTTP/2 spec value for {@link #getMaxHeaderListSize} : {@code Integer.MAX_VALUE}
+   * Default HTTP/2 spec value for {@link #getMaxHeaderListSize} : {@code 8192}
    */
-  public static final int DEFAULT_MAX_HEADER_LIST_SIZE = Integer.MAX_VALUE;
+  public static final int DEFAULT_MAX_HEADER_LIST_SIZE = 8192;
 
   /**
    * Default HTTP/2 spec value for {@link #getExtraSettings} : {@code null}

src/test/java/io/vertx/core/http/Http2Test.java

@@ -503,6 +503,23 @@ public void testInitialMaxConcurrentStreamZero() throws Exception {
     await();
   }
 
+  @Test
+  public void testMaxHaderListSize() throws Exception {
+    server.close();
+    server = vertx.createHttpServer(createBaseServerOptions().setInitialSettings(new Http2Settings().setMaxHeaderListSize(Integer.MAX_VALUE - 10 )));
+    server.requestHandler(req -> {
+      req.response().end();
+    });
+    startServer(testAddress);
+    client.request(new RequestOptions(requestOptions).setTimeout(10000))
+      .compose(HttpClientRequest::send)
+      .onComplete(onSuccess(resp -> {
+        assertEquals(Integer.MAX_VALUE, resp.request().connection().remoteSettings().getMaxHeaderListSize());
+        testComplete();
+      }));
+    await();
+  }
+
   @Test
   public void testFoo() throws Exception {
     waitFor(2);