fix on force return value flag. Fixes #47

Infinispan.Hotrod.Core.XUnitTest/DefaultCacheTest.cs

@@ -113,6 +113,13 @@ public async void PutTest()
             await _cache.Put(key2, "chlorine");
             Assert.Equal(initialSize + 2, await _cache.Size());
             Assert.Equal("chlorine", await _cache.Get(key2));
+
+            _cache.ForceReturnValue=true;
+            String key3 = UniqueKey.NextKey();
+            String oldVal = await _cache.Put(key3, "oxygen");
+            Assert.Null(oldVal);
+            oldVal = await _cache.Put(key3, "sodium");
+            Assert.Equal("oxygen", oldVal);
         }
 
         [Fact]
@@ -417,6 +424,32 @@ public async void PutAllTest()
             Assert.Equal("v3", await _cache.Get(key3));
         }
 
+
+        [Fact]
+        public async void PutIfAbsentTest()
+        {
+            String key1 = UniqueKey.NextKey();
+            Int32 initialSize = await _cache.Size();
+
+            await _cache.PutIfAbsent(key1, "boron");
+            Assert.Equal(initialSize + 1, await _cache.Size());
+            Assert.Equal("boron", await _cache.Get(key1));
+
+            await _cache.PutIfAbsent(key1, "chlorine");
+            Assert.Equal(initialSize + 1, await _cache.Size());
+            Assert.Equal("boron", await _cache.Get(key1));
+
+            _cache.ForceReturnValue = true;
+            String key2 = UniqueKey.NextKey();
+            String oldVal = await _cache.PutIfAbsent(key2, "boron2");
+            Assert.Equal(initialSize + 2, await _cache.Size());
+            Assert.Null(oldVal);
+            Assert.Equal("boron2", await _cache.Get(key2));
+            oldVal = await _cache.PutIfAbsent(key2, "chlorine2");
+            Assert.Equal(initialSize + 2, await _cache.Size());
+            Assert.Equal(oldVal, await _cache.Get(key2));
+        }
+
         // [Test]
         // public void ContainsValueTest()
         // {

src/InfinispanCommands/PUTIFABSENT.cs

@@ -43,7 +43,7 @@ internal override void Execute(CommandContext ctx, InfinispanClient client, Pipe
         }
         public override Result OnReceive(InfinispanRequest request, ResponseStream stream)
         {
-            if ((request.Command.Flags & 0x01) == 1)
+            if ((request.Command.Flags & 0x01) == 1 && request.ResponseStatus == 0x04)
             {
                 PrevValue = ValueMarshaller.unmarshall(Codec.readArray(stream));
                 return new Result { Status = ResultStatus.Completed, ResultType = ResultType.Object };

src/Marshaller.cs

@@ -38,11 +38,11 @@ public StringMarshaller(Encoding enc = null)
         }
         public override byte[] marshall(string t)
         {
-            return t == null ? null : Encoding.GetBytes(t);
+            return ((t == null) || (t.Length==0)) ? null : Encoding.GetBytes(t);
         }
         public override string unmarshall(byte[] buff)
         {
-            return buff == null ? null : Encoding.GetString(buff);
+            return ((buff == null) || (buff.Length==0)) ? null : Encoding.GetString(buff);
         }
     }
 }