OperatorObserveOn should not request more after child is unsubscribed

Author: davidmoten

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

@@ -185,7 +185,8 @@ void pollQueue() {
                 counter = 1;
                 long produced = 0;
                 long r = requested;
-                while (!child.isUnsubscribed()) {
+                boolean isUnsubscribed;
+                while (!(isUnsubscribed = child.isUnsubscribed())) {
                     Throwable error;
                     if (finished) {
                         if ((error = this.error) != null) {
@@ -214,6 +215,8 @@ void pollQueue() {
                         break;
                     }
                 }
+                if (isUnsubscribed)
+                    return;
                 if (produced > 0 && requested != Long.MAX_VALUE) {
                     REQUESTED.addAndGet(this, -produced);
                 }

src/test/java/rx/internal/operators/OperatorObserveOnTest.java

@@ -26,7 +26,9 @@
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
@@ -765,4 +767,42 @@ public void onNext(Integer t) {
 
     }
 
+    @Test
+    public void testNoMoreRequestsAfterUnsubscribe() throws InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(1);
+        final List<Long> requests = Collections.synchronizedList(new ArrayList<Long>());
+        Observable.range(1, 1000000)
+                .doOnRequest(new Action1<Long>() {
+
+                    @Override
+                    public void call(Long n) {
+                        requests.add(n);
+                    }
+                })
+                .observeOn(Schedulers.io())
+                .subscribe(new Subscriber<Integer>() {
+
+                    @Override
+                    public void onStart() {
+                        request(1);
+                    }
+
+                    @Override
+                    public void onCompleted() {
+                    }
+
+                    @Override
+                    public void onError(Throwable e) {
+                    }
+
+                    @Override
+                    public void onNext(Integer t) {
+                        unsubscribe();
+                        latch.countDown();
+                    }
+                });
+        assertTrue(latch.await(10, TimeUnit.SECONDS));
+        assertEquals(1, requests.size());
+    }
+    
 }