Lua Console: Print an error message when not opening the console beca…

…use :debug hasn't been run.

(cherry-picked from commit 012142a)

src/gui/dialogs/lua_interpreter.cpp

@@ -30,6 +30,7 @@
 #include "game_config.hpp"
 #include "game_errors.hpp"
 #include "gettext.hpp"
+#include "play_controller.hpp"
 #include "resources.hpp" //for help fetching lua kernel pointers
 #include "scripting/plugins/manager.hpp" //needed for the WHICH_KERNEL version of display
 #include "scripting/game_lua_kernel.hpp"	//needed for the WHICH_KERNEL version of display
@@ -685,6 +686,9 @@ void lua_interpreter::controller::search(int direction)
 void lua_interpreter::display(lua_kernel_base * lk) {
 #ifndef ALWAYS_HAVE_LUA_CONSOLE
 	if(!game_config::debug) {
+		display_chat_manager& chat_man = resources::controller->get_display().get_chat_manager();
+		const std::string& message = _("The lua console can only be used in debug mode! (Run ':debug' first)");
+		chat_man.add_chat_message(time(nullptr), _("lua console"), 0, message, events::chat_handler::MESSAGE_PRIVATE, false);
 		return;
 	}
 #endif