Fixes

src/RestSharp/Request/RequestContent.cs

@@ -16,6 +16,7 @@
 using System.Runtime.Serialization;
 using RestSharp.Extensions;
 using static RestSharp.KnownHeaders;
+// ReSharper disable InvertIf
 
 // ReSharper disable SuggestBaseTypeForParameter
 
@@ -153,9 +154,10 @@ void AddPostParameters(ParametersCollection? postParameters) {
         if (Content is MultipartFormDataContent mpContent) {
             // we got the multipart form already instantiated, just add parameters to it
             foreach (var postParameter in postParameters!) {
+                var parameterName = postParameter.Name!;
                 mpContent.Add(
                     new StringContent(postParameter.Value!.ToString()!, _client.Options.Encoding, postParameter.ContentType),
-                    postParameter.Name!
+                    _request.MultipartFormQuoteParameters ? $"\"{parameterName}\"" : parameterName
                 );
             }
         }

src/RestSharp/Request/RestRequest.cs

@@ -68,6 +68,13 @@ public RestRequest(Uri resource, Method method = Method.Get)
     /// </summary>
     public bool AlwaysMultipartFormData { get; set; }
 
+    /// <summary>
+    /// When set to true, parameters in a multipart form data requests will be enclosed in
+    /// quotation marks. Default is false. Enable it if the remote endpoint requires parameters
+    /// to be in quotes (for example, FreshDesk API). 
+    /// </summary>
+    public bool MultipartFormQuoteParameters { get; set; }
+
     public string? FormBoundary { get; set; }
 
     /// <summary>

src/RestSharp/Response/RestResponse.cs

@@ -61,11 +61,12 @@ public static RestResponse<T> FromResponse(RestResponse response)
 [DebuggerDisplay("{" + nameof(DebuggerDisplay) + "()}")]
 public class RestResponse : RestResponseBase {
     internal static async Task<RestResponse> FromHttpResponse(
-        HttpResponseMessage httpResponse,
-        RestRequest         request,
-        Encoding            encoding,
-        CookieCollection    cookieCollection,
-        CancellationToken   cancellationToken
+        HttpResponseMessage     httpResponse,
+        RestRequest             request,
+        Encoding                encoding,
+        CookieCollection        cookieCollection,
+        CalculateResponseStatus calculateResponseStatus,
+        CancellationToken       cancellationToken
     ) {
         return request.AdvancedResponseWriter?.Invoke(httpResponse) ?? await GetDefaultResponse().ConfigureAwait(false);
 
@@ -78,7 +79,7 @@ async Task<RestResponse> GetDefaultResponse() {
 #endif
 
             var bytes   = stream == null ? null : await stream.ReadAsBytes(cancellationToken).ConfigureAwait(false);
-            var content = bytes == null ? null : httpResponse.GetResponseString(bytes, encoding);
+            var content = bytes  == null ? null : httpResponse.GetResponseString(bytes, encoding);
 
             return new RestResponse {
                 Content           = content,
@@ -87,7 +88,7 @@ async Task<RestResponse> GetDefaultResponse() {
                 Version           = httpResponse.RequestMessage?.Version,
                 ContentLength     = httpResponse.Content.Headers.ContentLength,
                 ContentType       = httpResponse.Content.Headers.ContentType?.MediaType,
-                ResponseStatus    = httpResponse.IsSuccessStatusCode ? ResponseStatus.Completed : ResponseStatus.Error,
+                ResponseStatus    = calculateResponseStatus(httpResponse),
                 ErrorException    = MaybeException(),
                 ResponseUri       = httpResponse.RequestMessage!.RequestUri,
                 Server            = httpResponse.Headers.Server.ToString(),
@@ -122,4 +123,6 @@ async Task<RestResponse> GetDefaultResponse() {
             }
         }
     }
-}
+}
+
+public delegate ResponseStatus CalculateResponseStatus(HttpResponseMessage httpResponse);

src/RestSharp/RestClient.Async.cs

@@ -12,8 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-using RestSharp.Extensions;
-
 namespace RestSharp;
 
 public partial class RestClient {
@@ -33,6 +31,7 @@ public async Task<RestResponse> ExecuteAsync(RestRequest request, CancellationTo
                     request,
                     Options.Encoding,
                     CookieContainer.GetCookies(internalResponse.Url),
+                    CalculateResponseStatus,
                     cancellationToken
                 )
                 .ConfigureAwait(false)

src/RestSharp/RestClient.cs

@@ -35,6 +35,14 @@ public partial class RestClient : IDisposable {
     /// </summary>
     public string[] AcceptedContentTypes { get; set; } = null!;
 
+    /// <summary>
+    /// Function to calculate the response status. By default, the status will be Completed if it was successful, or NotFound.
+    /// </summary>
+    public CalculateResponseStatus CalculateResponseStatus { get; set; } = httpResponse
+        => httpResponse.IsSuccessStatusCode || httpResponse.StatusCode == HttpStatusCode.NotFound
+            ? ResponseStatus.Completed
+            : ResponseStatus.Error;
+
     HttpClient HttpClient { get; }
 
     internal RestClientOptions Options { get; }
@@ -103,8 +111,7 @@ public RestClient(HttpClient httpClient, RestClientOptions? options = null, bool
     public RestClient(HttpMessageHandler handler, bool disposeHandler = true) : this(new HttpClient(handler, disposeHandler), null, true) { }
 
     void ConfigureHttpClient(HttpClient httpClient) {
-        if (Options.Timeout > 0)
-            httpClient.Timeout = TimeSpan.FromMilliseconds(Options.Timeout);
+        if (Options.Timeout > 0) httpClient.Timeout = TimeSpan.FromMilliseconds(Options.Timeout);
         httpClient.DefaultRequestHeaders.UserAgent.ParseAdd(Options.UserAgent);
     }
 
@@ -126,8 +133,7 @@ void ConfigureHttpMessageHandler(HttpClientHandler handler) {
             handler.ClientCertificateOptions = ClientCertificateOption.Manual;
         }
 
-        if (Options.MaxRedirects.HasValue)
-            handler.MaxAutomaticRedirections = Options.MaxRedirects.Value;
+        if (Options.MaxRedirects.HasValue) handler.MaxAutomaticRedirections = Options.MaxRedirects.Value;
     }
 
     internal Func<string, string> Encode { get; set; } = s => s.UrlEncode();
@@ -153,7 +159,7 @@ public RestClient AddDefaultParameter(Parameter parameter) {
             );
 
         if (!Options.AllowMultipleDefaultParametersWithSameName &&
-            !MultiParameterTypes.Contains(parameter.Type) &&
+            !MultiParameterTypes.Contains(parameter.Type)       &&
             DefaultParameters.Any(x => x.Name == parameter.Name)) {
             throw new ArgumentException("A default parameters with the same name has already been added", nameof(parameter));
         }
@@ -212,4 +218,4 @@ public void Dispose() {
         Dispose(true);
         GC.SuppressFinalize(this);
     }
-}
+}

test/RestSharp.Tests.Integrated/RequestFailureTests.cs

@@ -34,28 +34,45 @@ public async Task Handles_GET_Request_Errors_With_Response_Type() {
     [Fact]
     public async Task Throws_on_unsuccessful_call() {
         var client  = new RestClient(new RestClientOptions(_fixture.Server.Url) { ThrowOnAnyError = true });
-        var request = new RestRequest("status?code=404");
+        var request = new RestRequest("status?code=500");
 
         var task = () => client.ExecuteAsync<Response>(request);
         await task.Should().ThrowExactlyAsync<HttpRequestException>();
     }
 
     [Fact]
     public async Task GetAsync_throws_on_unsuccessful_call() {
-        var request = new RestRequest("status?code=404");
+        var request = new RestRequest("status?code=500");
 
         var task = () => _client.GetAsync(request);
         await task.Should().ThrowExactlyAsync<HttpRequestException>();
     }
 
     [Fact]
-    public async Task GetAsync_generic_throws_on_unsuccessful_call() {
+    public async Task GetAsync_completes_on_404() {
         var request = new RestRequest("status?code=404");
 
+        var response = await _client.GetAsync(request);
+        response.StatusCode.Should().Be(HttpStatusCode.NotFound);
+        response.ResponseStatus.Should().Be(ResponseStatus.Completed);
+    }
+
+    [Fact]
+    public async Task GetAsync_generic_throws_on_unsuccessful_call() {
+        var request = new RestRequest("status?code=500");
+
         var task = () => _client.GetAsync<Response>(request);
         await task.Should().ThrowExactlyAsync<HttpRequestException>();
     }
 
+    [Fact]
+    public async Task GetAsync_returns_null_on_404() {
+        var request = new RestRequest("status?code=404");
+
+        var response = await _client.GetAsync<Response>(request);
+        response.Should().BeNull();
+    }
+
     class Response {
         public string Message { get; set; }
     }

test/RestSharp.Tests/UrlBuilderTests.cs

@@ -357,4 +357,15 @@ public void Should_update_parameter_if_it_already_exists() {
 
         Assert.Equal(expected, output);
     }
-}
+
+    [Fact]
+    public void Should_use_ipv6_address() {
+        var baseUrl = new Uri("https://[fe80::290:e8ff:fe8b:2537%en10]:8443");
+        var client  = new RestClient(baseUrl);
+        var request = new RestRequest("api/v1/auth");
+        var actual  = client.BuildUri(request);
+
+        actual.HostNameType.Should().Be(UriHostNameType.IPv6);
+        actual.AbsoluteUri.Should().Be("https://[fe80::290:e8ff:fe8b:2537]:8443/api/v1/auth");
+    }
+}