TEZ-4282: Possible NPE in LocalClient after TEZ-4236 (#103) (Laszlo Bodor reviewed by Panagiotis Garefalakis, Ashutosh Chauhan)

Author: abstractdog

tez-dag/src/main/java/org/apache/tez/client/LocalClient.java

@@ -157,7 +157,9 @@ public ApplicationId submitApplication(ApplicationSubmissionContext appContext)
   @Override
   public void killApplication(ApplicationId appId) {
     try {
-      clientHandler.shutdownAM();
+      if (clientHandler != null){
+        clientHandler.shutdownAM();
+      }
     } catch (TezException e) {
       throw new RuntimeException(e);
     }
@@ -403,7 +405,13 @@ protected DAGAppMaster createDAGAppMaster(ApplicationAttemptId applicationAttemp
   @Override
   public TezAppMasterStatus getAMStatus(Configuration configuration, ApplicationId appId,
       UserGroupInformation ugi) throws TezException, ServiceException, IOException {
-    return clientHandler.getTezAppMasterStatus();
+    if (isLocalWithoutNetwork) {
+      if (clientHandler == null) {
+        return TezAppMasterStatus.INITIALIZING;
+      }
+      return clientHandler.getTezAppMasterStatus();
+    }
+    return super.getAMStatus(configuration, appId, ugi);
   }
 
   @Override
@@ -438,10 +446,11 @@ public DAGStatus apply(Set<StatusGetOpts> statusOpts, Long timeout) {
   public boolean shutdownSession(Configuration configuration, ApplicationId sessionAppId,
       UserGroupInformation ugi) throws TezException, IOException, ServiceException {
     if (isLocalWithoutNetwork) {
-      clientHandler.shutdownAM();
+      if (clientHandler != null){
+        clientHandler.shutdownAM();
+      }
       return true;
-    } else {
-      return super.shutdownSession(configuration, sessionAppId, ugi);
     }
+    return super.shutdownSession(configuration, sessionAppId, ugi);
   }
 }