YARN-225. Proxy Link in RM UI thows NPE in Secure mode (Devaraj K via bobby)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1426515 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -248,6 +248,9 @@ Release 0.23.6 - UNRELEASED
     YARN-280. RM does not reject app submission with invalid tokens 
     (Daryn Sharp via tgraves)
 
+    YARN-225. Proxy Link in RM UI thows NPE in Secure mode 
+    (Devaraj K via bobby)
+
 Release 0.23.5 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/main/java/org/apache/hadoop/yarn/server/webproxy/WebAppProxyServlet.java

@@ -254,11 +254,14 @@ public class WebAppProxyServlet extends HttpServlet {
       
       if(securityEnabled) {
         String cookieName = getCheckCookieName(id); 
-        for(Cookie c: req.getCookies()) {
-          if(cookieName.equals(c.getName())) {
-            userWasWarned = true;
-            userApproved = userApproved || Boolean.valueOf(c.getValue());
-            break;
+        Cookie[] cookies = req.getCookies();
+        if (cookies != null) {
+          for (Cookie c : cookies) {
+            if (cookieName.equals(c.getName())) {
+              userWasWarned = true;
+              userApproved = userApproved || Boolean.valueOf(c.getValue());
+              break;
+            }
           }
         }
       }