fix missing guild id in GuildForumChannels

Author: topi314

discord/channel.go

@@ -1219,6 +1219,9 @@ func ApplyGuildIDToChannel(channel GuildChannel, guildID snowflake.ID) GuildChan
 	case GuildThread:
 		c.guildID = guildID
 		return c
+	case GuildForumChannel:
+		c.guildID = guildID
+		return c
 	default:
 		return channel
 	}

handlers/guild_create_handler.go

@@ -15,12 +15,12 @@ func gatewayHandlerGuildCreate(client bot.Client, sequenceNumber int, shardID in
 
 	for _, channel := range event.Channels {
 		channel = discord.ApplyGuildIDToChannel(channel, event.ID) // populate unset field
-		client.Caches().Channels().Put(channel.ID(), discord.ApplyGuildIDToChannel(channel, event.ID))
+		client.Caches().Channels().Put(channel.ID(), channel)
 	}
 
 	for _, thread := range event.Threads {
 		thread = discord.ApplyGuildIDToThread(thread, event.ID) // populate unset field
-		client.Caches().Channels().Put(thread.ID(), discord.ApplyGuildIDToThread(thread, event.ID))
+		client.Caches().Channels().Put(thread.ID(), thread)
 	}
 
 	for _, role := range event.Roles {