Fixing the chat client (tgstation#60920)

Corrects the chat restriction on using ASII characters only. (This PR was created for Skyrat-TG, but the collaborator of that repository asked me to adapt this PR for tgstation.)

This will fix tgstation#54598
In the original code, the chat client uses only ASII standard characters, which is very limited in its capabilities. For example, does not allow you to use specialized characters, which would have taken the atmosphere of the old messengers, as well as regional characters. The lack of regional characters complicates the game for non-English-speaking servers. For example, the Russian-speaking player community Space Station 13 The Fluffy Frontier uses the original Skyrat-tg build. And the players of this community almost do not use the chat client to communicate due to the fact that they can not use Cyrillic characters.

code/__HELPERS/text.dm

@@ -989,3 +989,27 @@ GLOBAL_LIST_INIT(binary, list("0","1"))
 		return word + "ay"
 	//otherwise unmutated
 	return word
+
+/**
+ * The procedure to check the text of the entered text on ntnrc_client.dm
+ *
+ * This procedure is designed to check the text you type into the chat client. 
+ * It checks for invalid characters and the size of the entered text. 
+ */
+/proc/reject_bad_chattext(text, max_length = 256)
+	var/non_whitespace = FALSE
+	var/char = ""
+	if (length(text) > max_length)
+		return
+	else
+		for(var/i = 1, i <= length(text), i += length(char))
+			char = text[i]
+			switch(text2ascii(char))
+				if(0 to 31)
+					return
+				if(32)
+					continue
+				else
+					non_whitespace = TRUE
+		if (non_whitespace)
+			return text

code/modules/modular_computers/file_system/programs/ntnrc_client.dm

@@ -1,3 +1,6 @@
+#define USERNAME_SIZE 32
+#define CHANNELNAME_SIZE 12
+#define MESSAGE_SIZE 2048
 
 /datum/computer_file/program/chatclient
 	filename = "ntnrc_client"
@@ -44,7 +47,7 @@
 		if("PRG_speak")
 			if(!channel || isnull(active_channel))
 				return
-			var/message = reject_bad_text(params["message"])
+			var/message = reject_bad_chattext(params["message"], MESSAGE_SIZE)
 			if(!message)
 				return
 			if(channel.password && (!(src in channel.active_clients) && !(src in channel.offline_clients)))
@@ -76,7 +79,7 @@
 				active_channel = null
 				return TRUE
 		if("PRG_newchannel")
-			var/channel_title = reject_bad_text(params["new_channel_name"])
+			var/channel_title = reject_bad_chattext(params["new_channel_name"], CHANNELNAME_SIZE)
 			if(!channel_title)
 				return
 			var/datum/ntnet_conversation/C = new /datum/ntnet_conversation()
@@ -99,7 +102,7 @@
 				netadmin_mode = TRUE
 				return TRUE
 		if("PRG_changename")
-			var/newname = sanitize(params["new_name"])
+			var/newname = reject_bad_chattext(params["new_name"], USERNAME_SIZE)
 			newname = replacetext(newname, " ", "_")
 			if(!newname || newname == username)
 				return
@@ -135,7 +138,7 @@
 		if("PRG_renamechannel")
 			if(!authed)
 				return
-			var/newname = reject_bad_text(params["new_name"])
+			var/newname = reject_bad_chattext(params["new_name"], CHANNELNAME_SIZE)
 			if(!newname || !channel)
 				return
 			channel.add_status_message("Channel renamed from [channel.title] to [newname] by operator.")
@@ -267,3 +270,7 @@
 		data["messages"] = list()
 
 	return data
+
+#undef USERNAME_SIZE
+#undef CHANNELNAME_SIZE
+#undef MESSAGE_SIZE