simplify org.springframework.cloud.netflix.zuul.filters.ProxyRequestH… (#1965)

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/ProxyRequestHelper.java

@@ -157,30 +157,15 @@ public class ProxyRequestHelper {
 			context.setResponseDataStream(entity);
 		}
 
-		HttpHeaders httpHeaders = new HttpHeaders();
-		for (Entry<String, List<String>> header : headers.entrySet()) {
-			List<String> values = header.getValue();
-			for (String value : values) {
-				httpHeaders.add(header.getKey(), value);
-			}
-		}
 		boolean isOriginResponseGzipped = false;
-		if (httpHeaders.containsKey(CONTENT_ENCODING)) {
-			List<String> collection = httpHeaders.get(CONTENT_ENCODING);
-			for (String header : collection) {
-				if (HTTPRequestUtils.getInstance().isGzipped(header)) {
-					isOriginResponseGzipped = true;
-					break;
-				}
-			}
-		}
-		context.setResponseGZipped(isOriginResponseGzipped);
-
 		for (Entry<String, List<String>> header : headers.entrySet()) {
 			String name = header.getKey();
 			for (String value : header.getValue()) {
-				context.addOriginResponseHeader(name, value);
-				if (name.equalsIgnoreCase(CONTENT_LENGTH)) {
+				if (name.equalsIgnoreCase(HttpHeaders.CONTENT_ENCODING)
+						&& HTTPRequestUtils.getInstance().isGzipped(value)) {
+					isOriginResponseGzipped = true;
+				}
+				if (name.equalsIgnoreCase(HttpHeaders.CONTENT_LENGTH)) {
 					context.setOriginContentLength(value);
 				}
 				if (isIncludedHeader(name)) {
@@ -188,6 +173,7 @@ public class ProxyRequestHelper {
 				}
 			}
 		}
+		context.setResponseGZipped(isOriginResponseGzipped);
 	}
 
 	public void addIgnoredHeaders(String... names) {