don't emit MissingBackpressureException

Author: davidmoten

src/main/java/rx/internal/operators/OnSubscribeRedo.java

@@ -236,15 +236,8 @@ public void onError(Throwable e) {
                     @Override
                     public void onNext(T v) {
                         if (!done) {
-                            if (consumerCapacity.get() == 0) {
-                                child.onError(new MissingBackpressureException(
-                                        "an item has arrived to this operator that was not requested, "
-                                                + "please use backpressure aware operators upstream (or insert .onBackpressureBuffer() or similar)"));
-                                return;
-                            } else {
-                                child.onNext(v);
-                                decrementConsumerCapacity();
-                            }
+                            child.onNext(v);
+                            decrementConsumerCapacity();
                         }
                     }
 
@@ -382,7 +375,7 @@ public void request(final long n) {
                     // producer will call setProducer and request with consumerCapacity on the new producer. 
                     producer.request(n);
                 } else
-                if (c == 0 && resumeBoundary.compareAndSet(true, false)) {
+                if (resumeBoundary.compareAndSet(true, false)) {
                     worker.schedule(subscribeToSource);
                 }
             }