Parse X-Forwarded-Port header even if X-Forwarded-Host is not present (#2761)

Always takes into account any available X-Forwarded-Port header even if the X-Forwarded-Host header is missing.
Fixes #2751

Author: pderop

reactor-netty-http/src/main/java/reactor/netty/http/server/DefaultHttpForwardedHeaderHandler.java

@@ -98,25 +98,31 @@ private ConnectionInfo parseXForwardedInfo(ConnectionInfo connectionInfo, HttpRe
 		}
 		String hostHeader = request.headers().get(X_FORWARDED_HOST_HEADER);
 		if (hostHeader != null) {
-			String scheme = connectionInfo.getScheme();
-			int port = scheme.equalsIgnoreCase("https") || scheme.equalsIgnoreCase("wss") ?
-					DEFAULT_HTTPS_PORT : DEFAULT_HTTP_PORT;
 			connectionInfo = connectionInfo.withHostAddress(
-					AddressUtils.parseAddress(hostHeader.split(",", 2)[0].trim(), port, DEFAULT_FORWARDED_HEADER_VALIDATION));
-			String portHeader = request.headers().get(X_FORWARDED_PORT_HEADER);
-			if (portHeader != null && !portHeader.isEmpty()) {
-				String portStr = portHeader.split(",", 2)[0].trim();
-				if (portStr.chars().allMatch(Character::isDigit)) {
-					port = Integer.parseInt(portStr);
-				}
-				else if (DEFAULT_FORWARDED_HEADER_VALIDATION) {
-					throw new IllegalArgumentException("Failed to parse a port from " + portHeader);
-				}
-				connectionInfo = connectionInfo.withHostAddress(
-						AddressUtils.createUnresolved(connectionInfo.getHostAddress().getHostString(), port));
+					AddressUtils.parseAddress(hostHeader.split(",", 2)[0].trim(),
+							getDefaultHostPort(connectionInfo), DEFAULT_FORWARDED_HEADER_VALIDATION));
+		}
+
+		String portHeader = request.headers().get(X_FORWARDED_PORT_HEADER);
+		if (portHeader != null && !portHeader.isEmpty()) {
+			String portStr = portHeader.split(",", 2)[0].trim();
+			if (portStr.chars().allMatch(Character::isDigit)) {
+				int port = Integer.parseInt(portStr);
+				connectionInfo = new ConnectionInfo(
+						AddressUtils.createUnresolved(connectionInfo.getHostAddress().getHostString(), port),
+						connectionInfo.getHostName(), port, connectionInfo.getRemoteAddress(), connectionInfo.getScheme());
+			}
+			else if (DEFAULT_FORWARDED_HEADER_VALIDATION) {
+				throw new IllegalArgumentException("Failed to parse a port from " + portHeader);
 			}
 		}
 		return connectionInfo;
 	}
 
+	private int getDefaultHostPort(ConnectionInfo connectionInfo) {
+		String scheme = connectionInfo.getScheme();
+		return scheme.equalsIgnoreCase("https") || scheme.equalsIgnoreCase("wss") ?
+				DEFAULT_HTTPS_PORT : DEFAULT_HTTP_PORT;
+	}
+
 }

reactor-netty-http/src/test/java/reactor/netty/http/server/ConnectionInfoTests.java

@@ -367,6 +367,32 @@ void xForwardedForMultipleHostAndPortAndProto() {
 				});
 	}
 
+	@Test
+	void xForwardedForAndHostOnly() throws SSLException {
+		SslContext clientSslContext = SslContextBuilder.forClient()
+				.trustManager(InsecureTrustManagerFactory.INSTANCE).build();
+		SslContext serverSslContext = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey()).build();
+
+		testClientRequest(
+				clientRequestHeaders -> {
+					clientRequestHeaders.add("Host", "a.example.com");
+					clientRequestHeaders.add("X-Forwarded-For", "192.168.0.1");
+					clientRequestHeaders.add("X-Forwarded-Port", "8443");
+					clientRequestHeaders.add("X-Forwarded-Proto", "https");
+				},
+				serverRequest -> {
+					Assertions.assertThat(serverRequest.remoteAddress().getHostString()).isEqualTo("192.168.0.1");
+					Assertions.assertThat(serverRequest.hostAddress().getHostString())
+							.containsPattern("^0:0:0:0:0:0:0:1(%\\w*)?|127.0.0.1$");
+					Assertions.assertThat(serverRequest.hostPort()).isEqualTo(8443);
+					Assertions.assertThat(serverRequest.hostName()).isEqualTo("a.example.com");
+					Assertions.assertThat(serverRequest.scheme()).isEqualTo("https");
+				},
+				httpClient -> httpClient.secure(ssl -> ssl.sslContext(clientSslContext)),
+				httpServer -> httpServer.secure(ssl -> ssl.sslContext(serverSslContext)),
+				true);
+	}
+
 	@Test
 	void customForwardedHandlerForMultipleHost() {
 		testClientRequest(