closes #436

src/Host/Configuration/Users.cs

@@ -17,7 +17,7 @@ public static List<InMemoryUser> Get()
             var users = new List<InMemoryUser>
             {
                 new InMemoryUser{Subject = "818727", Username = "alice", Password = "alice", 
-                    Claims = new Claim[]
+                    Claims = 
                     {
                         new Claim(JwtClaimTypes.Name, "Alice Smith"),
                         new Claim(JwtClaimTypes.GivenName, "Alice"),
@@ -31,7 +31,7 @@ public static List<InMemoryUser> Get()
                     }
                 },
                 new InMemoryUser{Subject = "88421113", Username = "bob", Password = "bob", 
-                    Claims = new Claim[]
+                    Claims = 
                     {
                         new Claim(JwtClaimTypes.Name, "Bob Smith"),
                         new Claim(JwtClaimTypes.GivenName, "Bob"),

src/IdentityServer4/Services/InMemory/InMemoryUser.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
 
 
+using IdentityModel;
 using System.Collections.Generic;
 using System.Security.Claims;
 
@@ -66,6 +67,6 @@ public class InMemoryUser
         /// <value>
         /// The claims.
         /// </value>
-        public IEnumerable<Claim> Claims { get; set; } = new List<Claim>();
+        public ICollection<Claim> Claims { get; set; } = new HashSet<Claim>(new ClaimComparer());
     }
 }