fix vanity url code and banner switchup

a mistake was made somewhere, that's all I know for sure

src/Discord.Net.Core/CDN.cs

@@ -78,18 +78,18 @@ namespace Discord
             => iconId != null ? $"{DiscordConfig.CDNUrl}channel-icons/{channelId}/{iconId}.jpg" : null;
 
         /// <summary>
-        ///     Returns a guild vanity URL.
+        ///     Returns a guild banner URL.
         /// </summary>
         /// <param name="guildId">The guild snowflake identifier.</param>
-        /// <param name="vanityId">The vanity image identifier.</param>
-        /// <param name="size">The size of the image to return in horizontal pixels. This can be any power of two between 16 and 2048.</param>
+        /// <param name="bannerId">The banner image identifier.</param>
+        /// <param name="size">The size of the image to return in horizontal pixels. This can be any power of two between 16 and 2048 inclusive.</param>
         /// <returns>
-        ///     A URL pointing to the guild's vanity image.
+        ///     A URL pointing to the guild's banner image.
         /// </returns>
-        public static string GetGuildVanityUrl(ulong guildId, string vanityId, ushort? size = null)
+        public static string GetGuildBannerUrl(ulong guildId, string bannerId, ushort? size = null)
         {
-            if (!string.IsNullOrEmpty(vanityId))
-                return $"{DiscordConfig.CDNUrl}banners/{guildId}/{vanityId}.jpg" + (size.HasValue ? $"?size={size}" : string.Empty);
+            if (!string.IsNullOrEmpty(bannerId))
+                return $"{DiscordConfig.CDNUrl}banners/{guildId}/{bannerId}.jpg" + (size.HasValue ? $"?size={size}" : string.Empty);
             return null;
         }
         /// <summary>

src/Discord.Net.Core/Entities/Guilds/IGuild.cs

@@ -204,19 +204,29 @@ namespace Discord
         /// </returns>
         PremiumTier PremiumTier { get; }
         /// <summary>
-        ///     Gets the identifier for this guilds vanity image.
+        ///     Gets the identifier for this guilds banner image.
+        /// </summary>
+        /// <returns>
+        ///     An identifier for the banner image; <c>null</c> if none is set.
+        /// </returns>
+        string BannerId { get; }
+        /// <summary>
+        ///     Gets the URL of this guild's banner image.
         /// </summary>
         /// <remarks>
-        ///     An identifier for the vanity image; <c>null</c> if none is set.
+        ///     This is referred to as the vanity image in the API.
         /// </remarks>
-        string VanityId { get; }
+        /// <returns>
+        ///     A URL pointing to the guild's banner image; <c>null</c> if none is set.
+        /// </returns>
+        string BannerUrl { get; }
         /// <summary>
-        ///     Gets the URL of this guild's vanity image.
+        ///     Gets the code for this guild's vanity invite URL.
         /// </summary>
         /// <returns>
-        ///     A URL pointing to the guild's vanity image; <c>null</c> if none is set.
+        ///     A string containing the vanity invite code for this guild; <c>null</c> if none is set.
         /// </returns>
-        string VanityUrl { get; }
+        string VanityURLCode { get; }
         /// <summary>
         ///     Gets the flags for the types of system channels that are disabled.
         /// </summary>

src/Discord.Net.Rest/API/Common/Guild.cs

@@ -49,6 +49,8 @@ namespace Discord.API
         public PremiumTier PremiumTier { get; set; }
         [JsonProperty("vanity_url_code")]
         public string VanityURLCode { get; set; }
+        [JsonProperty("banner")]
+        public string Banner { get; set; }
         [JsonProperty("description")]
         public string Description { get; set; }
         // this value is inverted, flags set will turn OFF features

src/Discord.Net.Rest/Entities/Guilds/RestGuild.cs

@@ -55,7 +55,9 @@ namespace Discord.Rest
         /// <inheritdoc />
         public PremiumTier PremiumTier { get; private set; }
         /// <inheritdoc />
-        public string VanityId { get; private set; }
+        public string BannerId { get; private set; }
+        /// <inheritdoc />
+        public string VanityURLCode { get; private set; }
         /// <inheritdoc />
         public SystemChannelMessageDeny SystemChannelFlags { get; private set; }
         /// <inheritdoc />
@@ -73,7 +75,7 @@ namespace Discord.Rest
         /// <inheritdoc />
         public string SplashUrl => CDN.GetGuildSplashUrl(Id, SplashId);
         /// <inheritdoc />
-        public string VanityUrl => CDN.GetGuildVanityUrl(Id, VanityId);
+        public string BannerUrl => CDN.GetGuildBannerUrl(Id, BannerId);
 
         /// <summary>
         ///     Gets the built-in role containing all users in this guild.
@@ -117,10 +119,12 @@ namespace Discord.Rest
             ExplicitContentFilter = model.ExplicitContentFilter;
             ApplicationId = model.ApplicationId;
             PremiumTier = model.PremiumTier;
-            VanityId = model.VanityURLCode;
+            VanityURLCode = model.VanityURLCode;
+            BannerId = model.Banner;
             SystemChannelFlags = model.SystemChannelFlags;
             Description = model.Description;
-            PremiumSubscriptionCount = model.PremiumSubscriptionCount.GetValueOrDefault();
+            if (model.PremiumSubscriptionCount.IsSpecified)
+                PremiumSubscriptionCount = model.PremiumSubscriptionCount.Value;
 
             if (model.Emojis != null)
             {

src/Discord.Net.WebSocket/Entities/Guilds/SocketGuild.cs

@@ -96,7 +96,9 @@ namespace Discord.WebSocket
         /// <inheritdoc />
         public PremiumTier PremiumTier { get; private set; }
         /// <inheritdoc />
-        public string VanityId { get; private set; }
+        public string BannerId { get; private set; }
+        /// <inheritdoc />
+        public string VanityURLCode { get; private set; }
         /// <inheritdoc />
         public SystemChannelMessageDeny SystemChannelFlags { get; private set; }
         /// <inheritdoc />
@@ -111,7 +113,7 @@ namespace Discord.WebSocket
         /// <inheritdoc />
         public string SplashUrl => CDN.GetGuildSplashUrl(Id, SplashId);
         /// <inheritdoc />
-        public string VanityUrl => CDN.GetGuildVanityUrl(Id, VanityId);
+        public string BannerUrl => CDN.GetGuildBannerUrl(Id, BannerId);
         /// <summary> Indicates whether the client has all the members downloaded to the local guild cache. </summary>
         public bool HasAllMembers => MemberCount == DownloadedMemberCount;// _downloaderPromise.Task.IsCompleted;
         /// <summary> Indicates whether the guild cache is synced to this guild. </summary>
@@ -367,7 +369,8 @@ namespace Discord.WebSocket
             ExplicitContentFilter = model.ExplicitContentFilter;
             ApplicationId = model.ApplicationId;
             PremiumTier = model.PremiumTier;
-            VanityId = model.VanityURLCode;
+            VanityURLCode = model.VanityURLCode;
+            BannerId = model.Banner;
             SystemChannelFlags = model.SystemChannelFlags;
             Description = model.Description;
             PremiumSubscriptionCount = model.PremiumSubscriptionCount.GetValueOrDefault();