Make deps/exprtk dependency optional

Guard the vendor event emission with obs_get_module("obs-websocket").
During obs_shutdown() modules are unloaded one-by-one; obs-websocket is
unloaded before advanced-scene-switcher, so the proc handler pointer (_ph)
cached in obs-websocket-api.h is already stale when FreeSceneSwitcher()
runs its stop steps. proc_handler_call() then dereferences freed memory
(use-after-free in pthread_mutex_unlock).

The existing OBSIsShuttingDown() guard does not catch this path: the
forced-exit that follows a "Source Cleanup Error" (scene collection
switch) never fires the SCRIPTING_SHUTDOWN frontend event, so the
plugin's obsIsShuttingDown flag is not set. obs_get_module() returns NULL
once the module is unloaded, which is the reliable signal that
obs-websocket's proc handler is gone.

Refs: #1404

CMakeLists.txt

@@ -383,8 +383,18 @@ target_precompile_headers(${LIB_NAME} PRIVATE
                           "${CMAKE_CURRENT_SOURCE_DIR}/lib/pch.hpp")
 
 target_include_directories(
-  ${LIB_NAME} PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/deps/obs-websocket/lib"
-                     "${CMAKE_CURRENT_SOURCE_DIR}/deps/exprtk")
+  ${LIB_NAME} PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/deps/obs-websocket/lib")
+
+if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/deps/exprtk/exprtk.hpp")
+  target_include_directories(${LIB_NAME}
+                             PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/deps/exprtk")
+  target_compile_definitions(${LIB_NAME} PRIVATE EXPRTK_SUPPORT=1)
+else()
+  message(
+    STATUS
+      "${PROJECT_NAME}: deps/exprtk not found - math expression support disabled"
+  )
+endif()
 
 if(NOT nlohmann_json_DIR
    AND EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/deps/json/CMakeLists.txt")

lib/utils/math-helpers.cpp

@@ -2,13 +2,16 @@
 #include "obs-module-helper.hpp"
 
 #include <climits>
+#ifdef EXPRTK_SUPPORT
 #include <exprtk.hpp>
 #include <random>
+#endif
 
 namespace advss {
 
 std::variant<double, std::string> EvalMathExpression(const std::string &expr)
 {
+#ifdef EXPRTK_SUPPORT
 	static auto randomFunc = []() {
 		thread_local std::mt19937 gen(std::random_device{}());
 		thread_local std::uniform_real_distribution<double> dis(0.0,
@@ -26,6 +29,7 @@ std::variant<double, std::string> EvalMathExpression(const std::string &expr)
 	if (parser.compile(expr, expression)) {
 		return expression.value();
 	}
+#endif
 	return std::string(obs_module_text(
 		       "AdvSceneSwitcher.math.expressionFail")) +
 	       " \"" + expr + "\"";

lib/utils/websocket-api.cpp

@@ -127,9 +127,10 @@ void RegisterWebsocketRequest(
 
 void SendWebsocketVendorEvent(const std::string &eventName, obs_data_t *data)
 {
-	if (OBSIsShuttingDown()) {
+	if (OBSIsShuttingDown() || !obs_get_module("obs-websocket")) {
 		return;
 	}
+
 	obs_websocket_vendor_emit_event(vendor, eventName.c_str(), data);
 }
 

plugins/twitch/token.cpp

@@ -233,7 +233,12 @@ void TwitchToken::Load(obs_data_t *obj)
 {
 	Item::Load(obj);
 	_token = obs_data_get_string(obj, "token");
-	_userID = obs_data_get_string(obj, "userID");
+	if (obs_data_has_user_value(obj, "userID") &&
+	    *obs_data_get_string(obj, "userID") != '\0') {
+		_userID = obs_data_get_string(obj, "userID");
+	} else {
+		_userID = {};
+	}
 	obs_data_set_default_bool(obj, "validateEventSubTimestamps", true);
 	_validateEventSubTimestamps =
 		obs_data_get_bool(obj, "validateEventSubTimestamps");
@@ -255,7 +260,7 @@ void TwitchToken::Save(obs_data_t *obj) const
 {
 	Item::Save(obj);
 	obs_data_set_string(obj, "token", _token.c_str());
-	if (_userID) {
+	if (_userID && !_userID->empty()) {
 		obs_data_set_string(obj, "userID", _userID->c_str());
 	}
 	obs_data_set_bool(obj, "validateEventSubTimestamps",
@@ -310,7 +315,7 @@ bool TwitchToken::AnyOptionIsEnabled(
 	return false;
 }
 
-void TwitchToken::SetToken(const std::string &value)
+bool TwitchToken::SetToken(const std::string &value)
 {
 	_token = value;
 	auto res =
@@ -318,21 +323,34 @@ void TwitchToken::SetToken(const std::string &value)
 	if (res.status != 200) {
 		blog(LOG_WARNING, "failed to get Twitch user id from token!");
 		_userID = {};
-		return;
+		return false;
 	}
 
+	bool gotUserID = false;
 	OBSDataArrayAutoRelease array = obs_data_get_array(res.data, "data");
 	size_t count = obs_data_array_count(array);
 	for (size_t i = 0; i < count; i++) {
 		OBSDataAutoRelease arrayObj = obs_data_array_item(array, i);
-		_userID = obs_data_get_string(arrayObj, "id");
+		std::string id = obs_data_get_string(arrayObj, "id");
+		if (id.empty()) {
+			blog(LOG_WARNING,
+			     "Twitch /helix/users response did not contain a user id!");
+			continue;
+		}
+		_userID = id;
 		_name = obs_data_get_string(arrayObj, "display_name");
+		gotUserID = true;
+	}
+
+	if (!gotUserID) {
+		return false;
 	}
 
 	// Trigger resubscribes with new token
 	if (_eventSub) {
 		_eventSub->ClearActiveSubscriptions();
 	}
+	return true;
 }
 
 std::optional<std::string> TwitchToken::GetToken() const
@@ -388,7 +406,7 @@ bool TwitchToken::IsValid(bool forceUpdate) const
 			return false;
 		}
 
-		if (_userID && _userID != id) {
+		if (_userID && !_userID->empty() && _userID != id) {
 			blog(LOG_INFO,
 			     "Twitch token %s does not match expected user (got %s, expected %s)!",
 			     _name.c_str(), id, _userID->c_str());
@@ -396,6 +414,10 @@ bool TwitchToken::IsValid(bool forceUpdate) const
 			return false;
 		}
 
+		if (!_userID || _userID->empty()) {
+			_userID = id;
+		}
+
 		_lastValidityCheckResult = true;
 		return true;
 	};
@@ -819,9 +841,9 @@ void TwitchTokenSettingsDialog::GotToken(const std::optional<QString> &value)
 		return;
 	}
 
-	_currentToken.SetToken(value.value().toStdString());
+	bool success = _currentToken.SetToken(value.value().toStdString());
 	auto name = QString::fromStdString(_currentToken._name);
-	if (name.isEmpty()) {
+	if (!success || name.isEmpty()) {
 		_tokenStatus->setText(obs_module_text(
 			"AdvSceneSwitcher.twitchToken.request.fail"));
 		_name->setText("");

plugins/twitch/token.hpp

@@ -48,7 +48,7 @@ public:
 	bool OptionIsActive(const TokenOption &option) const;
 	bool OptionIsEnabled(const TokenOption &option) const;
 	bool AnyOptionIsEnabled(const std::vector<TokenOption> &options) const;
-	void SetToken(const std::string &);
+	bool SetToken(const std::string &);
 	bool IsEmpty() const { return _token.empty(); }
 	std::optional<std::string> GetToken() const;
 	std::optional<std::string> GetUserID() const { return _userID; }
@@ -65,7 +65,7 @@ private:
 	mutable std::string _lastValidityCheckValue;
 	mutable bool _lastValidityCheckResult = false;
 	mutable std::chrono::system_clock::time_point _lastValidityCheckTime;
-	std::optional<std::string> _userID;
+	mutable std::optional<std::string> _userID;
 	std::set<TokenOption> _tokenOptions = TokenOption::GetAllTokenOptions();
 	std::shared_ptr<EventSub> _eventSub;
 	bool _validateEventSubTimestamps = false;

tests/CMakeLists.txt

@@ -85,8 +85,11 @@ target_sources(
   ${PROJECT_NAME}
   PRIVATE test-math.cpp ${ADVSS_SOURCE_DIR}/lib/utils/math-helpers.cpp
           ${ADVSS_SOURCE_DIR}/lib/utils/obs-module-helper.cpp)
-target_include_directories(${PROJECT_NAME}
-                           PRIVATE ${ADVSS_SOURCE_DIR}/deps/exprtk)
+if(EXISTS "${ADVSS_SOURCE_DIR}/deps/exprtk/exprtk.hpp")
+  target_include_directories(${PROJECT_NAME}
+                             PRIVATE ${ADVSS_SOURCE_DIR}/deps/exprtk)
+  target_compile_definitions(${PROJECT_NAME} PRIVATE EXPRTK_SUPPORT=1)
+endif()
 
 if(MSVC)
   target_compile_options(${PROJECT_NAME} PUBLIC /MP /d2FH4- /wd4267 /bigobj)