GUI: restore the Pause Menu after closing the Settings Menu

builtin/common/settings/dlg_settings.lua

@@ -518,7 +518,7 @@ local function get_formspec(dialogdata)
 
 		("button[0,%f;%f,0.8;back;%s]"):format(
 				tabsize.height + 0.2, back_w,
-				INIT == "pause_menu" and fgettext("Exit") or fgettext("Back")),
+				fgettext("Back")),
 
 		("box[%f,%f;%f,0.8;#0000008C]"):format(
 			back_w + 0.2, tabsize.height + 0.2, checkbox_w),

src/client/game_formspec.cpp

@@ -215,7 +215,6 @@ void GameFormSpec::deleteFormspec()
 		m_formspec->drop();
 		m_formspec = nullptr;
 	}
-	m_formname.clear();
 }
 
 GameFormSpec::~GameFormSpec() {
@@ -227,8 +226,10 @@ GameFormSpec::~GameFormSpec() {
 bool GameFormSpec::handleEmptyFormspec(const std::string &formspec, const std::string &formname)
 {
 	if (formspec.empty()) {
-		if (m_formspec && (formname.empty() || formname == m_formname)) {
+		GUIModalMenu *menu = g_menumgr.tryGetTopMenu();
-			m_formspec->quitMenu();
+		if (menu && (formname.empty() || formname == menu->getName())) {
+			// `m_formspec` will be fixed up in `GameFormSpec::update()`
+			menu->quitMenu();
 		}
 		return true;
 	}
@@ -245,10 +246,11 @@ void GameFormSpec::showFormSpec(const std::string &formspec, const std::string &
 	TextDestPlayerInventory *txt_dst =
 		new TextDestPlayerInventory(m_client, formname);
 
-	m_formname = formname;
+	// Replace the currently open formspec
 	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());
+	m_formspec->setName(formname);
 }
 
 void GameFormSpec::showCSMFormSpec(const std::string &formspec, const std::string &formname)
@@ -260,10 +262,10 @@ void GameFormSpec::showCSMFormSpec(const std::string &formspec, const std::strin
 	LocalScriptingFormspecHandler *txt_dst =
 		new LocalScriptingFormspecHandler(formname, m_client->getScript());
 
-	m_formname = formname;
 	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());
+	m_formspec->setName(formname);
 }
 
 void GameFormSpec::showPauseMenuFormSpec(const std::string &formspec, const std::string &formname)
@@ -272,20 +274,25 @@ void GameFormSpec::showPauseMenuFormSpec(const std::string &formspec, const std:
 	// the in-game settings formspec.
 	// Neither CSM nor the server must be allowed to mess with it.
 
-	if (handleEmptyFormspec(formspec, formname))
+	// If we send updated formspec contents, we can either (1) recycle the old
+	// GUIFormSpecMenu or (2) close the old and open a new one. This is option 2.
+	(void)handleEmptyFormspec("", formname);
+	if (formspec.empty())
 		return;
 
 	FormspecFormSource *fs_src = new FormspecFormSource(formspec);
 	LocalScriptingFormspecHandler *txt_dst =
 		new LocalScriptingFormspecHandler(formname, m_pause_script.get());
 
-	m_formname = formname;
+	GUIFormSpecMenu *fs = nullptr;
-	GUIFormSpecMenu::create(m_formspec, m_client, m_rendering_engine->get_gui_env(),
+	GUIFormSpecMenu::create(fs, m_client, m_rendering_engine->get_gui_env(),
 			// Ignore formspec prepend.
 			&m_input->joystick, fs_src, txt_dst, "",
 			m_client->getSoundManager());
 
-	m_formspec->doPause = true;
+	fs->setName(formname);
+	fs->doPause = true;
+	fs->drop(); // 1 reference held by `g_menumgr`
 }
 
 void GameFormSpec::showNodeFormspec(const std::string &formspec, const v3s16 &nodepos)
@@ -299,7 +306,6 @@ void GameFormSpec::showNodeFormspec(const std::string &formspec, const v3s16 &no
 		&m_client->getEnv().getClientMap(), nodepos);
 	TextDest *txt_dst = new TextDestNodeMetadata(nodepos, m_client);
 
-	m_formname = "";
 	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());
@@ -336,7 +342,7 @@ void GameFormSpec::showPlayerInventory()
 	}
 
 	TextDest *txt_dst = new TextDestPlayerInventory(m_client);
-	m_formname = "";
+
 	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());

src/client/game_formspec.h

@@ -55,9 +55,9 @@ private:
 	InputHandler *m_input;
 	std::unique_ptr<PauseMenuScripting> m_pause_script;
 
-	// Default: "". If other than "": Empty show_formspec packets will only
+	/// The currently open formspec that is not a submenu of the pause menu
-	// close the formspec when the formname matches
+	/// FIXME: Layering is already managed by `GUIModalMenu` (`g_menumgr`), hence this
-	std::string m_formname;
+	/// variable should be removed in long-term.
 	GUIFormSpecMenu *m_formspec = nullptr;
 
 	bool handleEmptyFormspec(const std::string &formspec, const std::string &formname);

src/gui/guiVolumeChange.cpp

@@ -77,7 +77,7 @@ void GUIVolumeChange::regenerateGui(v2u32 screensize)
 		core::rect<s32> rect(0, 0, 100 * s, 30 * s);
 		rect = rect + v2s32(size.X / 2 - 100 * s / 2, size.Y / 2 + 55 * s);
 		GUIButton::addButton(Environment, rect, m_tsrc, this, ID_soundExitButton,
-				wstrgettext("Exit").c_str());
+				wstrgettext("Back").c_str());
 	}
 	{
 		core::rect<s32> rect(0, 0, 300 * s, 20 * s);

src/gui/mainmenumanager.h

@@ -76,6 +76,13 @@ public:
 		return m_stack.size();
 	}
 
+	GUIModalMenu *tryGetTopMenu() const
+	{
+		if (m_stack.empty())
+			return nullptr;
+		return dynamic_cast<GUIModalMenu *>(m_stack.back());
+	}
+
 	void deleteFront()
 	{
 		m_stack.front()->setVisible(false);