Translate builtin (#10693)

This PR is the second attempt to translate builtin.
Server-sent translation files can be added to `builtin/locale/`, whereas client-side translations depend on gettext.

builtin/common/chatcommands.lua

@@ -1,5 +1,9 @@
 -- Minetest: builtin/common/chatcommands.lua
 
+-- For server-side translations (if INIT == "game")
+-- Otherwise, use core.gettext
+local S = core.get_translator("__builtin")
+
 core.registered_chatcommands = {}
 
 function core.register_chatcommand(cmd, def)
@@ -29,25 +33,12 @@ function core.override_chatcommand(name, redefinition)
 	core.registered_chatcommands[name] = chatcommand
 end
 
-local cmd_marker = "/"
-
-local function gettext(...)
-	return ...
-end
-
-local function gettext_replace(text, replace)
-	return text:gsub("$1", replace)
-end
-
-
-if INIT == "client" then
-	cmd_marker = "."
-	gettext = core.gettext
-	gettext_replace = fgettext_ne
-end
-
 local function do_help_cmd(name, param)
 	local function format_help_line(cmd, def)
+		local cmd_marker = "/"
+		if INIT == "client" then
+			cmd_marker = "."
+		end
 		local msg = core.colorize("#00ffff", cmd_marker .. cmd)
 		if def.params and def.params ~= "" then
 			msg = msg .. " " .. def.params
@@ -65,9 +56,21 @@ local function do_help_cmd(name, param)
 			end
 		end
 		table.sort(cmds)
-		return true, gettext("Available commands: ") .. table.concat(cmds, " ") .. "\n"
-				.. gettext_replace("Use '$1help <cmd>' to get more information,"
-				.. " or '$1help all' to list everything.", cmd_marker)
+		local msg
+		if INIT == "game" then
+			msg = S("Available commands: @1",
+				table.concat(cmds, " ")) .. "\n"
+				.. S("Use '/help <cmd>' to get more "
+				.. "information, or '/help all' to list "
+				.. "everything.")
+		else
+			msg = core.gettext("Available commands: ")
+				.. table.concat(cmds, " ") .. "\n"
+				.. core.gettext("Use '.help <cmd>' to get more "
+				.. "information, or '.help all' to list "
+				.. "everything.")
+		end
+		return true, msg
 	elseif param == "all" then
 		local cmds = {}
 		for cmd, def in pairs(core.registered_chatcommands) do
@@ -76,19 +79,31 @@ local function do_help_cmd(name, param)
 			end
 		end
 		table.sort(cmds)
-		return true, gettext("Available commands:").."\n"..table.concat(cmds, "\n")
+		local msg
+		if INIT == "game" then
+			msg = S("Available commands:")
+		else
+			msg = core.gettext("Available commands:")
+		end
+		return true, msg.."\n"..table.concat(cmds, "\n")
 	elseif INIT == "game" and param == "privs" then
 		local privs = {}
 		for priv, def in pairs(core.registered_privileges) do
 			privs[#privs + 1] = priv .. ": " .. def.description
 		end
 		table.sort(privs)
-		return true, "Available privileges:\n"..table.concat(privs, "\n")
+		return true, S("Available privileges:").."\n"..table.concat(privs, "\n")
 	else
 		local cmd = param
 		local def = core.registered_chatcommands[cmd]
 		if not def then
-			return false, gettext("Command not available: ")..cmd
+			local msg
+			if INIT == "game" then
+				msg = S("Command not available: @1", cmd)
+			else
+				msg = core.gettext("Command not available: ") .. cmd
+			end
+			return false, msg
 		else
 			return true, format_help_line(cmd, def)
 		end
@@ -97,16 +112,16 @@ end
 
 if INIT == "client" then
 	core.register_chatcommand("help", {
-		params = gettext("[all | <cmd>]"),
-		description = gettext("Get help for commands"),
+		params = core.gettext("[all | <cmd>]"),
+		description = core.gettext("Get help for commands"),
 		func = function(param)
 			return do_help_cmd(nil, param)
 		end,
 	})
 else
 	core.register_chatcommand("help", {
-		params = "[all | privs | <cmd>]",
-		description = "Get help for commands or list privileges",
+		params = S("[all | privs | <cmd>]"),
+		description = S("Get help for commands or list privileges"),
 		func = do_help_cmd,
 	})
 end