Hook it up into a working demo state

builtin/client/register.lua

@@ -55,7 +55,7 @@ local function make_registration()
 	local registerfunc = function(func)
 		t[#t + 1] = func
 		core.callback_origins[func] = {
-			mod = core.get_current_modname() or "??",
+			mod = core.get_current_modname and core.get_current_modname() or "??",
 			name = getinfo(1, "n").name or "??"
 		}
 		--local origin = core.callback_origins[func]

builtin/common/settings/dlg_settings.lua

@@ -772,3 +772,28 @@ function create_settings_dlg()
 
 	return dlg
 end
+
+if INIT == "pause_menu" then
+	local dialog
+
+	core.register_on_formspec_input(function(formname, fields)
+		if dialog and formname == "__builtin:settings" then
+			-- dialog is re-checked since the buttonhandler may have closed it
+			if buttonhandler(dialog, fields) and dialog then
+				core.show_formspec("__builtin:settings", get_formspec(dialog.data))
+			end
+		end
+	end)
+
+	core.open_settings = function()
+		load()
+		dialog = {}
+		dialog.data = {}
+		dialog.page_id = update_filtered_pages("")
+		dialog.delete = function()
+			dialog = nil
+		end
+
+		core.show_formspec("__builtin:settings", get_formspec(dialog.data))
+	end
+end

builtin/common/settings/settingtypes.lua

@@ -408,7 +408,7 @@ function settingtypes.parse_config_file(read_all, parse_mods)
 		file:close()
 	end
 
-	if parse_mods then
+	if INIT == "mainmenu" and parse_mods then
 		-- Parse games
 		local games_category_initialized = false
 		for _, game in ipairs(pkgmgr.games) do

builtin/pause_menu/init.lua

@@ -0,0 +1,9 @@
+local scriptpath = core.get_builtin_path()
+local clientpath = scriptpath.."client"..DIR_DELIM
+local commonpath = scriptpath.."common"..DIR_DELIM
+
+-- we're in-game, so no absolute paths are needed
+defaulttexturedir = ""
+
+dofile(clientpath .. "register.lua")
+dofile(commonpath .. "settings" .. DIR_DELIM .. "init.lua")

src/client/game_formspec.cpp

@@ -77,8 +77,8 @@ struct LocalFormspecHandler : public TextDest
 		m_formname = formname;
 	}
 
-	LocalFormspecHandler(const std::string &formname, Client *client):
+	LocalFormspecHandler(const std::string &formname, Client *client, PauseMenuScripting *pause_script):
-		m_client(client)
+		m_client(client), m_pause_script(pause_script)
 	{
 		m_formname = formname;
 	}
@@ -136,11 +136,17 @@ struct LocalFormspecHandler : public TextDest
 			return;
 		}
 
-		if (m_client->modsLoaded())
+		if (m_pause_script &&
-			m_client->getScript()->on_formspec_input(m_formname, fields);
+				m_pause_script->on_formspec_input(m_formname, fields))
+			return;
+
+		if (m_client && m_client->modsLoaded() &&
+				m_client->getScript()->on_formspec_input(m_formname, fields))
+			return;
 	}
 
 	Client *m_client = nullptr;
+	PauseMenuScripting *m_pause_script = nullptr;
 };
 
 /* Form update callback */
@@ -236,7 +242,7 @@ void GameFormSpec::showLocalFormSpec(const std::string &formspec, const std::str
 {
 	FormspecFormSource *fs_src = new FormspecFormSource(formspec);
 	LocalFormspecHandler *txt_dst =
-		new LocalFormspecHandler(formname, m_client);
+		new LocalFormspecHandler(formname, m_client, m_pause_script.get());
 	GUIFormSpecMenu::create(m_formspec, m_client, m_rendering_engine->get_gui_env(),
 			&m_input->joystick, fs_src, txt_dst, m_client->getFormspecPrepend(),
 			m_client->getSoundManager());
@@ -427,7 +433,7 @@ void GameFormSpec::showDeathFormspecLegacy()
 	/* Note: FormspecFormSource and LocalFormspecHandler  *
 	 * are deleted by guiFormSpecMenu                     */
 	FormspecFormSource *fs_src = new FormspecFormSource(formspec_str);
-	LocalFormspecHandler *txt_dst = new LocalFormspecHandler("MT_DEATH_SCREEN", m_client);
+	LocalFormspecHandler *txt_dst = new LocalFormspecHandler("MT_DEATH_SCREEN", m_client, m_pause_script.get());
 
 	GUIFormSpecMenu::create(m_formspec, m_client, m_rendering_engine->get_gui_env(),
 		&m_input->joystick, fs_src, txt_dst, m_client->getFormspecPrepend(),