Don't allow null intents in billing service

astrid/src/com/todoroo/astrid/billing/BillingActivity.java

@@ -68,9 +68,26 @@ public class BillingActivity extends Activity {
             }
         };
 
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
         ResponseHandler.register(purchaseObserver);
     }
 
+    @Override
+    protected void onStop() {
+        super.onStop();
+        ResponseHandler.unregister(purchaseObserver);
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        billingService.unbind();
+    }
+
     @Override
     protected void onResume() {
         super.onResume();

astrid/src/com/todoroo/astrid/billing/BillingService.java

@@ -403,6 +403,8 @@ public class BillingService extends Service implements ServiceConnection {
      * @param startId an identifier for the invocation instance of this service
      */
     public void handleCommand(Intent intent, int startId) {
+        if (intent == null)
+            return;
         String action = intent.getAction();
         if (Constants.DEBUG) {
             Log.i(TAG, "handleCommand() action: " + action);