Fix for bug #1331802.

Updated the HttpAbstractionClient code to check for a null content buffer when trying to send a POST or PUT request.
Added a unit test case to check for this bug.

Closes-Bug: #1331802
Change-Id: I99d93e77a0a5ca4c3678c825517050ab4e3f6789

OpenStack/OpenStack.Test/HttpAbstraction/HttpAbstractionClientTests.cs

@@ -135,6 +135,30 @@ namespace OpenStack.Test.HttpAbstraction
             }
         }
 
+        [TestMethod]
+        [TestCategory("Integration")]
+        [TestCategory("LongRunning")]
+        public void CanMakePostRequestWithNullContent()
+        {
+            using (var client = new HttpAbstractionClientFactory().Create())
+            {
+                client.Uri = new Uri("http://httpbin.org/post");
+                client.Method = HttpMethod.Post;
+
+                var responseTask = client.SendAsync();
+                responseTask.Wait();
+                var response = responseTask.Result;
+
+                Assert.IsNotNull(response);
+                Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
+
+                var stringContent = TestHelper.GetStringFromStream(response.Content);
+
+                Assert.IsTrue(stringContent.Contains("\"data\": \"\""));
+
+            }
+        }
+
         [TestMethod]
         [TestCategory("Integration")]
         [TestCategory("LongRunning")]

OpenStack/OpenStack/Common/Http/HttpAbstractionClient.cs

@@ -79,10 +79,13 @@ namespace OpenStack.Common.Http
 
             if (this.Method == HttpMethod.Post || this.Method == HttpMethod.Put)
             {
-                requestMessage.Content = new StreamContent(this.Content);
+                if (this.Content != null)
-                if (this.ContentType != string.Empty)
                 {
-                    requestMessage.Content.Headers.ContentType = new MediaTypeHeaderValue(this.ContentType);
+                    requestMessage.Content = new StreamContent(this.Content);
+                    if (this.ContentType != string.Empty)
+                    {
+                        requestMessage.Content.Headers.ContentType = new MediaTypeHeaderValue(this.ContentType);
+                    }
                 }
             }