Fixes: U4-3558 members tree syncing is a bit strange and not showing the selected member

src/Umbraco.Web/Editors/MemberController.cs

@@ -54,6 +54,16 @@ namespace Umbraco.Web.Editors
         {
         }
 
+        /// <summary>
+        /// Ensure all GUIDs are formatted without hyphens
+        /// </summary>
+        /// <param name="controllerContext"></param>
+        protected override void Initialize(System.Web.Http.Controllers.HttpControllerContext controllerContext)
+        {
+            base.Initialize(controllerContext);
+            controllerContext.SetOutgoingNoHyphenGuidFormat();
+        }
+
         /// <summary>
         /// Returns the currently configured membership scenario for members in umbraco
         /// </summary>

src/Umbraco.Web/Models/Mapping/MemberModelMapper.cs

@@ -37,7 +37,7 @@ namespace Umbraco.Web.Models.Mapping
                   .ForMember(member => member.CreateDate, expression => expression.MapFrom(user => user.CreationDate))
                   .ForMember(member => member.UpdateDate, expression => expression.MapFrom(user => user.LastActivityDate))
                   .ForMember(member => member.LastPasswordChangeDate, expression => expression.MapFrom(user => user.LastPasswordChangedDate))
-                  .ForMember(member => member.Key, expression => expression.MapFrom(user => user.ProviderUserKey.TryConvertTo<Guid>().Result))
+                  .ForMember(member => member.Key, expression => expression.MapFrom(user => user.ProviderUserKey.TryConvertTo<Guid>().Result.ToString("N")))
                   //This is a special case for password - we don't actually care what the password is but it either needs to be something or nothing
                   // so we'll set it to something if the member is actually created, otherwise nothing if it is a new member.
                   .ForMember(member => member.Password, expression => expression.MapFrom(user => user.CreationDate > DateTime.MinValue ? Guid.NewGuid().ToString("N") : ""))

src/Umbraco.Web/Trees/MemberTreeController.cs

@@ -61,7 +61,7 @@ namespace Umbraco.Web.Trees
                         int total;
                         nodes.AddRange(
                             Membership.Provider.FindUsersByName(id + "%", 0, 9999, out total).Cast<MembershipUser>()
-                                      .Select(m => CreateTreeNode(m.ProviderUserKey.ToString(), id, queryStrings, m.UserName, "icon-user")));
+                                      .Select(m => CreateTreeNode(GetNodeIdForCustomProvider(m.ProviderUserKey), id, queryStrings, m.UserName, "icon-user")));
                     }
                 }
                 else if (id == "others")
@@ -75,6 +75,22 @@ namespace Umbraco.Web.Trees
             return nodes;
         }
 
+        /// <summary>
+        /// We'll see if it is a GUID, if so we'll ensure to format it without hyphens
+        /// </summary>
+        /// <param name="providerUserKey"></param>
+        /// <returns></returns>
+        private string GetNodeIdForCustomProvider(object providerUserKey)
+        {
+            if (providerUserKey == null) throw new ArgumentNullException("providerUserKey");
+            var guidAttempt = providerUserKey.TryConvertTo<Guid>();
+            if (guidAttempt.Success)
+            {
+                return guidAttempt.Result.ToString("N");
+            }
+            return providerUserKey.ToString();
+        }
+
         protected override MenuItemCollection GetMenuForNode(string id, FormDataCollection queryStrings)
         {
             var menu = new MenuItemCollection();

src/Umbraco.Web/Umbraco.Web.csproj

@@ -655,6 +655,7 @@
     <Compile Include="WebApi\Filters\HttpQueryStringFilterAttribute.cs" />
     <Compile Include="WebApi\Filters\OutgoingDateTimeFormatAttribute.cs" />
     <Compile Include="WebApi\Filters\UmbracoApplicationAuthorizeAttribute.cs" />
+    <Compile Include="WebApi\GuidNoHyphenConverter.cs" />
     <Compile Include="WebApi\HttpRequestMessageExtensions.cs" />
     <Compile Include="WebApi\MemberAuthorizeAttribute.cs" />
     <Compile Include="WebApi\UmbracoApiController.cs" />

src/Umbraco.Web/WebApi/ControllerContextExtensions.cs

@@ -5,6 +5,17 @@ namespace Umbraco.Web.WebApi
 {
     internal static class ControllerContextExtensions
     {
+        /// <summary>
+        /// Sets the JSON GUID format to not have hyphens
+        /// </summary>
+        /// <param name="controllerContext"></param>
+        internal static void SetOutgoingNoHyphenGuidFormat(this HttpControllerContext controllerContext)
+        {
+            var jsonFormatter = controllerContext.Configuration.Formatters.JsonFormatter;
+            jsonFormatter.SerializerSettings.Converters.Add(new GuidNoHyphenConverter());
+        }
+
+
         /// <summary>
         /// Sets the JSON datetime format to be a custom one
         /// </summary>

src/Umbraco.Web/WebApi/GuidNoHyphenConverter.cs

@@ -0,0 +1,40 @@
+using System;
+using Newtonsoft.Json;
+using Umbraco.Core;
+
+namespace Umbraco.Web.WebApi
+{
+    /// <summary>
+    /// A custom converter for GUID's to format without hyphens
+    /// </summary>
+    internal class GuidNoHyphenConverter : JsonConverter
+    {
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            switch (reader.TokenType)
+            {
+                case JsonToken.Null:
+                    return Guid.Empty;
+                case JsonToken.String:
+                    var guidAttempt = reader.Value.TryConvertTo<Guid>();
+                    if (guidAttempt.Success)
+                    {
+                        return guidAttempt.Result;
+                    }
+                    throw new FormatException("Could not convert " + reader.Value + " to a GUID");
+                default:
+                    throw new ArgumentException("Invalid token type");
+            }
+        }
+
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            writer.WriteValue(Guid.Empty.Equals(value) ? "" : ((Guid) value).ToString("N"));
+        }
+
+        public override bool CanConvert(Type objectType)
+        {
+            return typeof(Guid) == objectType;
+        }
+    }
+}