fix fabric8io#3384: addressing that in can be null

CHANGELOG.md

@@ -5,6 +5,7 @@
 #### Bugs
 * Fix #3445: TokenRefreshInterceptor throws when running incluster config
 * Fix #3456: io.fabric8:crd-generator README should reference crd-generator-apt instead of now removed crd-generator artifact
+* Fix #3384: preventing NPE from being logged with pod execs.
 
 #### Improvements
 * Fix #3398: Added javadocs explaining the wait parameter

kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/internal/ExecWebSocketListener.java

@@ -175,11 +175,11 @@ public void onOpen(WebSocket webSocket, Response response) {
             }
 
             webSocketRef.set(webSocket);
-            if (!executorService.isShutdown()) {
+            if (in != null && !executorService.isShutdown()) {
               // the task will be cancelled via shutdownNow
               InputStreamPumper.pump(InputStreamPumper.asInterruptible(in), this::send, executorService);
-              startedFuture.complete(null);
             }
+            startedFuture.complete(null);
         } catch (IOException e) {
           startedFuture.completeExceptionally(new KubernetesClientException(OperationSupport.createStatus(response)));
         } finally {
@@ -268,22 +268,27 @@ public void onClosed(WebSocket webSocket, int code, String reason) {
         }
     }
 
+    @Override
     public OutputStream getInput() {
         return input;
     }
 
+    @Override
     public InputStream getOutput() {
         return output;
     }
 
+    @Override
     public InputStream getError() {
         return error;
     }
 
+    @Override
     public InputStream getErrorChannel() {
         return errorChannel;
     }
 
+    @Override
     public void resize(int cols, int rows) {
       if (cols < 0 || rows < 0) {
         return;