[Fix] Banish table.maxn from Lua parts

rules/rspamd.classifiers.lua

 	local st_many = classifier:get_statfile_by_label(many_recipients_label)
 	if st_many then
 		rcpt = task:get_recipients(2)
-		if rcpt and table.maxn(rcpt) > 5 then
-			print(table.maxn(rcpt))
+		if rcpt and #rcpt > 5 then
 			table.foreach(st_many, function(i,v) table.insert(spec_st,v) end)
 		end
 	end
 	local st_undisc = classifier:get_statfile_by_label(undisclosed_recipients_label)
 	if st_undisc then
 		rcpt = task:get_recipients(2)
-		if rcpt and table.maxn(rcpt) == 0 then
+		if rcpt and #rcpt == 0 then
 			table.foreach(st_undisc, function(i,v) table.insert(spec_st,v) end)
 		end
 	end
 		end
 	end
 	
-	if table.maxn(spec_st) > 1 then
+	if #spec_st > 1 then
 		return spec_st
 	else
 		return nil
 				end
 			end
 		end
-		if table.maxn(selected) > 1 then
+		if #selected > 1 then
 			return selected
 		end
 	end
 			end
 		end
 	end
-	if table.maxn(selected) > 1 then
+	if #selected > 1 then
 		return selected
 	end
 	

src/lua/lua_mimepart.c

 @example
 rspamd_config.MISSING_CONTENT_TYPE = function(task)
 	local parts = task:get_parts()
-	if parts and table.maxn(parts) > 1 then
+	if parts and #parts > 1 then
 		-- We have more than one part
 		for _,p in ipairs(parts) do
 			local ct = p:get_header('Content-Type')

src/plugins/lua/emails.lua

   end
 end
 
-if table.maxn(rules) > 0 then
+if #rules > 0 then
   -- add fake symbol to check all maps inside a single callback
   local id = rspamd_config:register_symbol({
     type = 'callback',

src/plugins/lua/forged_recipients.lua

     local mime_rcpt = task:get_recipients(2)
     local count = 0
     if mime_rcpt then
-      count = table.maxn(mime_rcpt)
+      count = #mime_rcpt
     end
-    if count > 0 and count < table.maxn(smtp_rcpt) then
+    if count > 0 and count < #smtp_rcpt then
       task:insert_result(symbol_rcpt, 1)
     elseif count > 0 then
       -- Find pair for each smtp recipient recipient in To or Cc headers

src/plugins/lua/hfilter.lua

       --FROM host check
       for _,fr in ipairs(from) do
         local fr_split = rspamd_str_split(fr['addr'], '@')
-        if table.maxn(fr_split) == 2 then
+        if #fr_split == 2 then
           check_host(task, fr_split[2], 'FROMHOST', '', '')
           if fr_split[1] == 'postmaster' then
             frombounce = true
   if config['rcpt_enabled'] then
     local rcpt = task:get_recipients()
     if rcpt then
-      local count_rcpt = table.maxn(rcpt)
+      local count_rcpt = #rcpt
       if frombounce then
         if count_rcpt > 1 then
           task:insert_result('HFILTER_RCPT_BOUNCEMOREONE', 1.00)
     local message_id = task:get_message_id()
     if message_id then
       local mid_split = rspamd_str_split(message_id, '@')
-      if table.maxn(mid_split) == 2 and not string.find(mid_split[2], 'local') then
+      if #mid_split == 2 and not string.find(mid_split[2], 'local') then
         check_host(task, mid_split[2], 'MID')
       end
     end
 end
 
 --dumper(symbols_enabled)
-if table.maxn(symbols_enabled) > 0 then
+if #symbols_enabled > 0 then
   rspamd_config:register_symbols(hfilter, 1.0, "HFILTER", symbols_enabled);
 end

src/plugins/lua/ratelimit.lua

     limit[2] = tonumber(rate)
   end
 
-  if table.maxn(params) ~= 3 then
+  if #params ~= 3 then
     rspamd_logger.errx(rspamd_config, 'invalid limit definition: ' .. str)
     return
   end