add unit test to ensure that range with count of 0 sends onComplete even when initial request is 0

Author: davidmoten

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

@@ -17,6 +17,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
@@ -26,6 +27,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.junit.Test;
@@ -77,7 +79,7 @@ public void call(Integer t1) {
     }
 
     @Test
-    public void testRangeWithOverflow() {
+    public void testRangeWithZero() {
         Observable.range(1, 0);
     }
 
@@ -220,4 +222,31 @@ public void onNext(Integer t) {
             }});
         assertEquals(n, count.get());
     }
+    
+    @Test
+    public void testEmptyRangeSendsOnCompleteEagerlyWithRequestZero() {
+        final AtomicBoolean completed = new AtomicBoolean(false);
+        Observable.range(1, 0).subscribe(new Subscriber<Integer>() {
+
+            @Override
+            public void onStart() {
+                request(0);
+            }
+            
+            @Override
+            public void onCompleted() {
+                completed.set(true);
+            }
+
+            @Override
+            public void onError(Throwable e) {
+                
+            }
+
+            @Override
+            public void onNext(Integer t) {
+                
+            }});
+        assertTrue(completed.get());
+    }
 }