fix(ChannelUpdate): Check against unknown channels (#9697)

fix(ChannelUpdate): check against unknown channels

Author: Jiralite

packages/discord.js/src/client/actions/ChannelUpdate.js

@@ -6,14 +6,23 @@ const { createChannel } = require('../../util/Channels');
 class ChannelUpdateAction extends Action {
   handle(data) {
     const client = this.client;
-
     let channel = client.channels.cache.get(data.id);
+
     if (channel) {
       const old = channel._update(data);
 
       if (channel.type !== data.type) {
         const newChannel = createChannel(this.client, data, channel.guild);
-        for (const [id, message] of channel.messages.cache) newChannel.messages.cache.set(id, message);
+
+        if (!newChannel) {
+          this.client.channels.cache.delete(channel.id);
+          return {};
+        }
+
+        if (channel.isTextBased() && newChannel.isTextBased()) {
+          for (const [id, message] of channel.messages.cache) newChannel.messages.cache.set(id, message);
+        }
+
         channel = newChannel;
         this.client.channels.cache.set(channel.id, channel);
       }