This proves a bug with the ForwardedHeadersFilter (#440)

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/headers/ForwardedHeadersFilterTests.java

@@ -17,6 +17,9 @@
 
 package org.springframework.cloud.gateway.filter.headers;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.cloud.gateway.filter.headers.ForwardedHeadersFilter.FORWARDED_HEADER;
+
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.UnknownHostException;
@@ -27,16 +30,12 @@ import java.util.List;
 import java.util.Map;
 
 import org.junit.Test;
-
 import org.springframework.cloud.gateway.filter.headers.ForwardedHeadersFilter.Forwarded;
 import org.springframework.http.HttpHeaders;
 import org.springframework.mock.http.server.reactive.MockServerHttpRequest;
 import org.springframework.mock.web.server.MockServerWebExchange;
 import org.springframework.util.StringUtils;
 
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.springframework.cloud.gateway.filter.headers.ForwardedHeadersFilter.FORWARDED_HEADER;
-
 /**
  * @author Spencer Gibb
  */
@@ -67,6 +66,36 @@ public class ForwardedHeadersFilterTests {
 				.containsEntry("for", "\"10.0.0.1:80\"");
 	}
 
+	@Test
+	public void forwardedHeaderExists() throws UnknownHostException {
+		MockServerHttpRequest request = MockServerHttpRequest
+				.get("http://localhost/get")
+				.remoteAddress(new InetSocketAddress(InetAddress.getByName("10.0.0.1"), 80))
+				.header(FORWARDED_HEADER, "for=12.34.56.78;host=example.com;proto=https; for=23.45.67.89")
+				.build();
+
+		ForwardedHeadersFilter filter = new ForwardedHeadersFilter();
+
+		HttpHeaders headers = filter.filter(request.getHeaders(), MockServerWebExchange.from(request));
+
+		assertThat(headers.get(FORWARDED_HEADER)).hasSize(2);
+
+
+		List<Forwarded> forwardeds = ForwardedHeadersFilter.parse(headers.get(FORWARDED_HEADER));
+
+		assertThat(forwardeds).hasSize(2);
+		Forwarded addedForwardedHeader = forwardeds.get(0);
+		Forwarded existingForwardedHeader = forwardeds.get(1);
+
+		assertThat(existingForwardedHeader.getValues())
+				.containsEntry("proto", "http")
+				.containsEntry("for", "\"10.0.0.1:80\"");
+
+		assertThat(addedForwardedHeader.getValues())
+				.containsEntry("proto", "https")
+				.containsEntry("for", "23.45.67.89");
+	}
+
 	@Test
 	public void noHostHeader() throws UnknownHostException {
 		MockServerHttpRequest request = MockServerHttpRequest