Fixed takeUntil not unsubscribing from either of the observables in case

of a terminal condition.

Author: akarnokd

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

@@ -36,28 +36,62 @@ public OperatorTakeUntil(final Observable<? extends E> other) {
 
     @Override
     public Subscriber<? super T> call(final Subscriber<? super T> child) {
-        final Subscriber<T> parent = new SerializedSubscriber<T>(child);
-
-        other.unsafeSubscribe(new Subscriber<E>(child) {
-
+        final Subscriber<T> serial = new SerializedSubscriber<T>(child, false);
+        
+        final Subscriber<T> main = new Subscriber<T>(serial, false) {
+            @Override
+            public void onNext(T t) {
+                serial.onNext(t);
+            }
+            @Override
+            public void onError(Throwable e) {
+                try {
+                    serial.onError(e);
+                } finally {
+                    serial.unsubscribe();
+                }
+            }
             @Override
             public void onCompleted() {
-                parent.onCompleted();
+                try {
+                    serial.onCompleted();
+                } finally {
+                    serial.unsubscribe();
+                }
+            }
+        };
+        
+        final Subscriber<E> so = new Subscriber<E>() {
+            @Override
+            public void onStart() {
+                request(Long.MAX_VALUE);
+            }
+            
+            @Override
+            public void onCompleted() {
+                main.onCompleted();
             }
 
             @Override
             public void onError(Throwable e) {
-                parent.onError(e);
+                main.onError(e);
             }
 
             @Override
             public void onNext(E t) {
-                parent.onCompleted();
+                onCompleted();
             }
 
-        });
+        };
+
+        serial.add(main);
+        serial.add(so);
+        
+        child.add(serial);
+        
+        other.unsafeSubscribe(so);
 
-        return parent;
+        return main;
     }
 
 }

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

@@ -15,16 +15,20 @@
  */
 package rx.internal.operators;
 
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.*;
+
+import java.util.Arrays;
 
 import org.junit.Test;
 
 import rx.Observable;
 import rx.Observer;
 import rx.Subscriber;
 import rx.Subscription;
+import rx.observers.TestSubscriber;
+import rx.subjects.PublishSubject;
 
 public class OperatorTakeUntilTest {
 
@@ -188,4 +192,98 @@ public void call(Subscriber<? super String> observer) {
             observer.add(s);
         }
     }
+    
+    @Test
+    public void testUntilFires() {
+        PublishSubject<Integer> source = PublishSubject.create();
+        PublishSubject<Integer> until = PublishSubject.create();
+        
+        TestSubscriber<Integer> ts = new TestSubscriber<Integer>();
+        
+        source.takeUntil(until).unsafeSubscribe(ts);
+
+        assertTrue(source.hasObservers());
+        assertTrue(until.hasObservers());
+
+        source.onNext(1);
+        
+        ts.assertReceivedOnNext(Arrays.asList(1));
+        until.onNext(1);
+        
+        ts.assertReceivedOnNext(Arrays.asList(1));
+        ts.assertNoErrors();
+        ts.assertTerminalEvent();
+        
+        assertFalse("Source still has observers", source.hasObservers());
+        assertFalse("Until still has observers", until.hasObservers());
+        assertFalse("TestSubscriber is unsubscribed", ts.isUnsubscribed());
+    }
+    @Test
+    public void testMainCompletes() {
+        PublishSubject<Integer> source = PublishSubject.create();
+        PublishSubject<Integer> until = PublishSubject.create();
+        
+        TestSubscriber<Integer> ts = new TestSubscriber<Integer>();
+        
+        source.takeUntil(until).unsafeSubscribe(ts);
+
+        assertTrue(source.hasObservers());
+        assertTrue(until.hasObservers());
+
+        source.onNext(1);
+        source.onCompleted();
+        
+        ts.assertReceivedOnNext(Arrays.asList(1));
+        ts.assertNoErrors();
+        ts.assertTerminalEvent();
+        
+        assertFalse("Source still has observers", source.hasObservers());
+        assertFalse("Until still has observers", until.hasObservers());
+        assertFalse("TestSubscriber is unsubscribed", ts.isUnsubscribed());
+    }
+    @Test
+    public void testDownstreamUnsubscribes() {
+        PublishSubject<Integer> source = PublishSubject.create();
+        PublishSubject<Integer> until = PublishSubject.create();
+        
+        TestSubscriber<Integer> ts = new TestSubscriber<Integer>();
+        
+        source.takeUntil(until).take(1).unsafeSubscribe(ts);
+
+        assertTrue(source.hasObservers());
+        assertTrue(until.hasObservers());
+
+        source.onNext(1);
+        
+        ts.assertReceivedOnNext(Arrays.asList(1));
+        ts.assertNoErrors();
+        ts.assertTerminalEvent();
+        
+        assertFalse("Source still has observers", source.hasObservers());
+        assertFalse("Until still has observers", until.hasObservers());
+        assertFalse("TestSubscriber is unsubscribed", ts.isUnsubscribed());
+    }
+    public void testBackpressure() {
+        PublishSubject<Integer> until = PublishSubject.create();
+        
+        TestSubscriber<Integer> ts = new TestSubscriber<Integer>() {
+            @Override
+            public void onStart() {
+                requestMore(0);
+            }
+        };
+        
+        Observable.range(1, 10).takeUntil(until).unsafeSubscribe(ts);
+
+        assertTrue(until.hasObservers());
+
+        ts.requestMore(1);
+        
+        ts.assertReceivedOnNext(Arrays.asList(1));
+        ts.assertNoErrors();
+        assertTrue("TestSubscriber completed", ts.getOnCompletedEvents().isEmpty());
+        
+        assertFalse("Until still has observers", until.hasObservers());
+        assertFalse("TestSubscriber is unsubscribed", ts.isUnsubscribed());
+    }
 }