request with Accept: application/xml responds with 500

[chihoyeung]

I only tried it on the /resourcetypes endpoint. Since application/xml is not supported, it should respond with a 415 instead.

see test: when_retrieving_resource_types_error.cs

Here is the exception I get:

{"schemas":["urn:ietf:params:scim:api:messages:2.0:Error"],"status":"500","scimType":null,"detail":"Type 'System.Collections.Generic.Dictionary`2+ValueCollection[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[Owin.Scim.v2.Model.ResourceType, Owin.Scim.v2, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]' with data contract name 'Dictionary.ValueCollectionOfstringResourceTypedo7g_PmCO:http://schemas.datacontract.org/2004/07/System.Collections.Generic' is not expected. Consider using a DataContractResolver if you are using DataContractSerializer or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to the serializer.\r\n at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeAndVerifyType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, Boolean verifyKnownType, RuntimeTypeHandle declaredTypeHandle, Type declaredType)\r\n at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithXsiTypeAtTopLevel(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle originalDeclaredTypeHandle, Type graphType)\r\n at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)\r\n at System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)\r\n at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)\r\n at System.Runtime.Serialization.DataContractSerializer.WriteObject(XmlWriter writer, Object graph)\r\n at System.Net.Http.Formatting.XmlMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, HttpContent content)\r\n at System.Net.Http.Formatting.XmlMediaTypeFormatter.WriteToStreamAsync(Type type, Object value, Stream writeStream, HttpContent content, TransportContext transportContext, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Owin.HttpMessageHandlerAdapter.d__13.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at Owin.Scim.Configuration.OwinScimExceptionHandler.HandleAsync(ExceptionHandlerContext context, CancellationToken cancellationToken) in C:\git\Owin.Scim\source\Owin.Scim\Configuration\OwinScimExceptionHandler.cs:line 23\r\n at System.Web.Http.ExceptionHandling.LastChanceExceptionHandler.HandleAsync(ExceptionHandlerContext context, CancellationToken cancellationToken)\r\n at System.Web.Http.ExceptionHandling.ExceptionHandlerExtensions.d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Owin.HttpMessageHandlerAdapter.d__13.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Owin.HttpMessageHandlerAdapter.d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.GetResult()\r\n at Owin.Scim.Middleware.ExceptionHandlerMiddleware.d__2.MoveNext() in C:\git\Owin.Scim\source\Owin.Scim\Middleware\ExceptionHandlerMiddleware.cs:line 48"}