Fixed User nullref errors

src/Discord.Net/API/Common/User.cs

@@ -7,20 +7,20 @@ namespace Discord.API
         [JsonProperty("id")]
         public ulong Id { get; set; }
         [JsonProperty("username")]
-        public string Username { get; set; }
+        public Optional<string> Username { get; set; }
         [JsonProperty("discriminator")]
-        public string Discriminator { get; set; }
+        public Optional<string> Discriminator { get; set; }
         [JsonProperty("bot")]
-        public bool Bot { get; set; }
+        public Optional<bool> Bot { get; set; }
         [JsonProperty("avatar")]
-        public string Avatar { get; set; }
+        public Optional<string> Avatar { get; set; }
 
         //CurrentUser
         [JsonProperty("verified")]
-        public bool Verified { get; set; }
+        public Optional<bool> Verified { get; set; }
         [JsonProperty("email")]
-        public string Email { get; set; }
+        public Optional<string> Email { get; set; }
         [JsonProperty("mfa_enabled")]
-        public bool MfaEnabled { get; set; }
+        public Optional<bool> MfaEnabled { get; set; }
     }
 }

src/Discord.Net/Data/DataStore.cs

@@ -58,9 +58,16 @@ namespace Discord
         internal void AddChannel(ICachedChannel channel)
         {
             _channels[channel.Id] = channel;
+
             var dmChannel = channel as CachedDMChannel;
             if (dmChannel != null)
                 _dmChannels[dmChannel.Recipient.Id] = dmChannel;
+            else
+            {
+                var groupChannel = channel as CachedGroupChannel;
+                if (groupChannel != null)
+                    _groupChannels.TryAdd(groupChannel.Id);
+            }
         }
         internal ICachedChannel RemoveChannel(ulong id)
         {
@@ -73,6 +80,12 @@ namespace Discord
                     CachedDMChannel ignored;
                     _dmChannels.TryRemove(dmChannel.Recipient.Id, out ignored);
                 }
+                else
+                {
+                    var groupChannel = channel as CachedGroupChannel;
+                    if (groupChannel != null)
+                        _groupChannels.TryRemove(id);
+                }
                 return channel;
             }
             return null;

src/Discord.Net/DiscordSocketClient.cs

@@ -528,7 +528,6 @@ namespace Discord
 
                                     var currentUser = new CachedSelfUser(this, data.User);
                                     int unavailableGuilds = 0;
-                                    //dataStore.GetOrAddUser(data.User.Id, _ => currentUser);
                                     for (int i = 0; i < data.Guilds.Length; i++)
                                     {
                                         var model = data.Guilds[i];

src/Discord.Net/Entities/Users/SelfUser.cs

@@ -31,9 +31,12 @@ namespace Discord
 
             base.Update(model, source);
 
-            Email = model.Email;
-            IsVerified = model.Verified;
-            IsMfaEnabled = model.MfaEnabled;
+            if (model.Email.IsSpecified)
+                Email = model.Email.Value;
+            if (model.Verified.IsSpecified)
+                IsVerified = model.Verified.Value;
+            if (model.MfaEnabled.IsSpecified)
+                IsMfaEnabled = model.MfaEnabled.Value;
         }
         
         public async Task UpdateAsync()

src/Discord.Net/Entities/Users/User.cs

@@ -31,10 +31,14 @@ namespace Discord
         {
             if (source == UpdateSource.Rest && IsAttached) return;
 
-            _avatarId = model.Avatar;
-            DiscriminatorValue = ushort.Parse(model.Discriminator);
-            IsBot = model.Bot;
-            Username = model.Username;
+            if (model.Avatar.IsSpecified)
+                _avatarId = model.Avatar.Value;
+            if (model.Discriminator.IsSpecified)
+                DiscriminatorValue = ushort.Parse(model.Discriminator.Value);
+            if (model.Bot.IsSpecified)
+                IsBot = model.Bot.Value;
+            if (model.Username.IsSpecified)
+                Username = model.Username.Value;
         }
 
         public override string ToString() => $"{Username}#{Discriminator}";