fix decrement of consumerCapacity so doesn't decrement Long.MAX_VALUE, remove c==0 check in request method because of race condition

Author: davidmoten

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

@@ -235,10 +235,23 @@ public void onError(Throwable e) {
                     @Override
                     public void onNext(T v) {
                         if (!done) {
-                            if (consumerCapacity.get() != Long.MAX_VALUE) {
-                                consumerCapacity.decrementAndGet();
-                            }
                             child.onNext(v);
+                            decrementConsumerCapacity();
+                        }
+                    }
+                    
+                    private void decrementConsumerCapacity() {
+                        // use a CAS loop because we don't want to decrement the value 
+                        // if it is Long.MAX_VALUE
+                        while (true) {
+                            long cc = consumerCapacity.get();
+                            if (cc != Long.MAX_VALUE) {
+                                if (consumerCapacity.compareAndSet(cc, cc - 1)) {
+                                    break;
+                                }
+                            } else {
+                                break;
+                            }
                         }
                     }
 
@@ -334,12 +347,12 @@ public void setProducer(Producer producer) {
 
             @Override
             public void request(final long n) {
-                long c = BackpressureUtils.getAndAddRequest(consumerCapacity, n);
+                BackpressureUtils.getAndAddRequest(consumerCapacity, n);
                 Producer producer = currentProducer.get();
                 if (producer != null) {
                     producer.request(n);
                 } else
-                if (c == 0 && resumeBoundary.compareAndSet(true, false)) {
+                if (resumeBoundary.compareAndSet(true, false)) {
                     worker.schedule(subscribeToSource);
                 }
             }

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

@@ -783,10 +783,10 @@ static <T> StringBuilder allSequenceFrequency(Map<Integer, List<T>> its) {
     }
     static <T> StringBuilder sequenceFrequency(Iterable<T> it) {
         StringBuilder sb = new StringBuilder();
-        
+
         Object prev = null;
         int cnt = 0;
-        
+
         for (Object curr : it) {
             if (sb.length() > 0) {
                 if (!curr.equals(prev)) {
@@ -805,7 +805,10 @@ static <T> StringBuilder sequenceFrequency(Iterable<T> it) {
             }
             prev = curr;
         }
-        
+        if (cnt > 1) {
+            sb.append(" x ").append(cnt);
+        }
+
         return sb;
     }
     @Test(timeout = 3000)