Merge pull request #3630 from akarnokd/ConcatMapEagerInnerNPEFix1x

1.x: ConcatMapEager allow nulls from inner Observables.

Author: zsxwing

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

@@ -166,6 +166,7 @@ void drain() {
 
             final AtomicLong requested = sharedProducer;
             final Subscriber<? super R> actualSubscriber = this.actual;
+            final NotificationLite<R> nl = NotificationLite.instance();
 
             for (;;) {
 
@@ -200,13 +201,13 @@ void drain() {
                     long emittedAmount = 0L;
                     boolean unbounded = requestedAmount == Long.MAX_VALUE;
 
-                    Queue<R> innerQueue = innerSubscriber.queue;
+                    Queue<Object> innerQueue = innerSubscriber.queue;
                     boolean innerDone = false;
 
 
                     for (;;) {
                         outerDone = innerSubscriber.done;
-                        R v = innerQueue.peek();
+                        Object v = innerQueue.peek();
                         empty = v == null;
 
                         if (outerDone) {
@@ -237,7 +238,7 @@ void drain() {
                         innerQueue.poll();
 
                         try {
-                            actualSubscriber.onNext(v);
+                            actualSubscriber.onNext(nl.getValue(v));
                         } catch (Throwable ex) {
                             Exceptions.throwOrReport(ex, actualSubscriber, v);
                             return;
@@ -271,27 +272,29 @@ void drain() {
 
     static final class EagerInnerSubscriber<T> extends Subscriber<T> {
         final EagerOuterSubscriber<?, T> parent;
-        final Queue<T> queue;
+        final Queue<Object> queue;
+        final NotificationLite<T> nl;
 
         volatile boolean done;
         Throwable error;
 
         public EagerInnerSubscriber(EagerOuterSubscriber<?, T> parent, int bufferSize) {
             super();
             this.parent = parent;
-            Queue<T> q;
+            Queue<Object> q;
             if (UnsafeAccess.isUnsafeAvailable()) {
-                q = new SpscArrayQueue<T>(bufferSize);
+                q = new SpscArrayQueue<Object>(bufferSize);
             } else {
-                q = new SpscAtomicArrayQueue<T>(bufferSize);
+                q = new SpscAtomicArrayQueue<Object>(bufferSize);
             }
             this.queue = q;
+            this.nl = NotificationLite.instance();
             request(bufferSize);
         }
 
         @Override
         public void onNext(T t) {
-            queue.offer(t);
+            queue.offer(nl.next(t));
             parent.drain();
         }
 

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

@@ -394,4 +394,20 @@ public void call(Integer t) {
         ts.assertNotCompleted();
         Assert.assertEquals(RxRingBuffer.SIZE, count.get());
     }
+    
+    @Test
+    public void testInnerNull() {
+        TestSubscriber<Object> ts = TestSubscriber.create();
+        
+        Observable.just(1).concatMapEager(new Func1<Integer, Observable<Integer>>() {
+            @Override
+            public Observable<Integer> call(Integer t) {
+                return Observable.just(null);
+            }
+        }).subscribe(ts);
+        
+        ts.assertNoErrors();
+        ts.assertCompleted();
+        ts.assertValue(null);
+    }
 }