Only enable validation of headers if original headers were validating as well.

Motiviation:

In our replace(...) methods we always used validation for the newly created headers while the original headers may not use validation at all.

Modifications:

- Only use validation if the original headers used validation as well.
- Ensure we create a copy of the headers in replace(...).

Result:

Fixes [#5226]

codec-http/src/main/java/io/netty/handler/codec/http/DefaultFullHttpRequest.java

@@ -142,7 +142,10 @@ public class DefaultFullHttpRequest extends DefaultHttpRequest implements FullHt
 
     @Override
     public FullHttpRequest replace(ByteBuf content) {
-        return new DefaultFullHttpRequest(protocolVersion(), method(), uri(), content, headers(), trailingHeaders());
+        FullHttpRequest request = new DefaultFullHttpRequest(protocolVersion(), method(), uri(), content,
+                headers().copy(), trailingHeaders().copy());
+        request.setDecoderResult(decoderResult());
+        return request;
     }
 
     @Override

codec-http/src/main/java/io/netty/handler/codec/http/DefaultFullHttpResponse.java

@@ -149,7 +149,10 @@ public class DefaultFullHttpResponse extends DefaultHttpResponse implements Full
 
     @Override
     public FullHttpResponse replace(ByteBuf content) {
-        return new DefaultFullHttpResponse(protocolVersion(), status(), content, headers(), trailingHeaders());
+        FullHttpResponse response = new DefaultFullHttpResponse(protocolVersion(), status(), content,
+                headers().copy(), trailingHeaders().copy());
+        response.setDecoderResult(decoderResult());
+        return response;
     }
 
     @Override

codec-http/src/main/java/io/netty/handler/codec/http/DefaultHttpHeaders.java

@@ -348,6 +348,11 @@ public class DefaultHttpHeaders extends HttpHeaders {
         return headers.hashCode(CASE_SENSITIVE_HASHER);
     }
 
+    @Override
+    public HttpHeaders copy() {
+        return new DefaultHttpHeaders(headers.copy());
+    }
+
     private static void validateHeaderNameElement(byte value) {
         switch (value) {
         case 0x00:

codec-http/src/main/java/io/netty/handler/codec/http/HttpHeaders.java

@@ -1693,4 +1693,11 @@ public abstract class HttpHeaders implements Iterable<Map.Entry<String, String>>
     public String toString() {
         return HeadersUtils.toString(getClass(), iteratorCharSequence(), size());
     }
+
+    /**
+     * Returns a deap copy of the passed in {@link HttpHeaders}.
+     */
+    public HttpHeaders copy() {
+        return new DefaultHttpHeaders().set(this);
+    }
 }

codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectAggregator.java

@@ -424,9 +424,8 @@ public class HttpObjectAggregator
 
         @Override
         public FullHttpRequest replace(ByteBuf content) {
-            DefaultFullHttpRequest dup = new DefaultFullHttpRequest(protocolVersion(), method(), uri(), content);
-            dup.headers().set(headers());
-            dup.trailingHeaders().set(trailingHeaders());
+            DefaultFullHttpRequest dup = new DefaultFullHttpRequest(protocolVersion(), method(), uri(), content,
+                    headers().copy(), trailingHeaders().copy());
             dup.setDecoderResult(decoderResult());
             return dup;
         }
@@ -523,9 +522,8 @@ public class HttpObjectAggregator
 
         @Override
         public FullHttpResponse replace(ByteBuf content) {
-            DefaultFullHttpResponse dup = new DefaultFullHttpResponse(getProtocolVersion(), getStatus(), content);
-            dup.headers().set(headers());
-            dup.trailingHeaders().set(trailingHeaders());
+            DefaultFullHttpResponse dup = new DefaultFullHttpResponse(getProtocolVersion(), getStatus(), content,
+                    headers().copy(), trailingHeaders().copy());
             dup.setDecoderResult(decoderResult());
             return dup;
         }

codec-http2/src/test/java/io/netty/handler/codec/http2/InboundHttp2ToHttpAdapterTest.java

@@ -62,6 +62,7 @@ import static io.netty.handler.codec.http2.Http2TestUtil.of;
 import static io.netty.handler.codec.http2.Http2TestUtil.runInChannel;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -607,6 +608,9 @@ public class InboundHttp2ToHttpAdapterTest {
             verify(serverListener, times(2)).messageReceived(requestCaptor.capture());
             capturedRequests = requestCaptor.getAllValues();
             assertEquals(2, capturedRequests.size());
+            // We do not expect to have this header in the captured request so remove it now.
+            assertNotNull(request.headers().remove("x-http2-stream-weight"));
+
             assertEquals(request, capturedRequests.get(0));
             assertEquals(request2, capturedRequests.get(1));
 

codec/src/main/java/io/netty/handler/codec/DefaultHeaders.java

@@ -952,6 +952,16 @@ public class DefaultHeaders<K, V, T extends Headers<K, V, T>> implements Headers
         return (T) this;
     }
 
+    /**
+     * Returns a deep copy of this instance.
+     */
+    public DefaultHeaders<K, V, T> copy() {
+        DefaultHeaders<K, V, T> copy = new DefaultHeaders<K, V, T>(
+                hashingStrategy, valueConverter, nameValidator, entries.length);
+        copy.addImpl(this);
+        return copy;
+    }
+
     private final class HeaderIterator implements Iterator<Map.Entry<K, V>> {
         private HeaderEntry<K, V> current = head;