Merge github.com:nickvane/RestSharp

Author: ayoung

RestSharp/RestClient.Sync.cs

@@ -79,7 +79,6 @@ private IRestResponse Execute(IRestRequest request, string httpMethod, Func<IHtt
 			return response;
 		}
 
-
 		private static HttpResponse DoExecuteAsGet(IHttp http, string method)
 		{
 			return http.AsGet(method);

RestSharp/RestClient.cs

@@ -90,6 +90,10 @@ public void AddHandler(string contentType, IDeserializer deserializer)
 			if (contentType != "*")
 			{
 				AcceptTypes.Add(contentType);
+				// add Accept header based on registered deserializers
+				var accepts = string.Join(", ", AcceptTypes.ToArray());
+				this.RemoveDefaultParameter("Accept");
+				this.AddDefaultParameter("Accept", accepts, ParameterType.HttpHeader);
 			}
 		}
 
@@ -101,6 +105,7 @@ public void RemoveHandler(string contentType)
 		{
 			ContentHandlers.Remove(contentType);
 			AcceptTypes.Remove(contentType);
+			this.RemoveDefaultParameter("Accept");
 		}
 
 		/// <summary>
@@ -110,6 +115,7 @@ public void ClearHandlers()
 		{
 			ContentHandlers.Clear();
 			AcceptTypes.Clear();
+			this.RemoveDefaultParameter("Accept");
 		}
 
 		/// <summary>

RestSharp/RestClientExtensions.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 
 namespace RestSharp
 {
@@ -213,6 +214,21 @@ public static void AddDefaultParameter(this IRestClient restClient, Parameter p)
 			restClient.DefaultParameters.Add(p);
 		}
 
+        /// <summary>
+        /// Removes a parameter from the default parameters that are used on every request made with this client instance
+        /// </summary>
+        /// <param name="restClient">The IRestClient instance</param>
+        /// <param name="name">The name of the parameter that needs to be removed</param>
+        /// <returns></returns>
+        public static void RemoveDefaultParameter(this IRestClient restClient, string name)
+        {
+            var parameter = restClient.DefaultParameters.SingleOrDefault(p => p.Name.Equals(name, StringComparison.OrdinalIgnoreCase));
+            if (parameter != null)
+            {
+                restClient.DefaultParameters.Remove(parameter);
+            }
+        }
+
 		/// <summary>
 		/// Adds a HTTP parameter (QueryString for GET, DELETE, OPTIONS and HEAD; Encoded form for POST and PUT)
 		/// Used on every request made by this client instance