core/log: crash if Quickshell's log filter is installed twice

Crashes from recursion inside filterCategories through the old filter
have been observed. Presumably this means the log filter is getting
installed twice somehow. This should catch it.

changelog/next.md

@@ -70,6 +70,7 @@ set shell id.
 - Fixed JsonAdapter crashing and providing bad data on read when using JsonObject.
 - Fixed JsonAdapter sending unnecessary property changes for primitive values.
 - Fixed JsonAdapter serialization for lists.
+- Fixed pipewire crashes after hotplugging devices and changing default outputs.
 
 ## Packaging Changes
 

src/core/logging.cpp

@@ -310,10 +310,15 @@ void LogManager::init(
 		instance->rules->append(parser.rules());
 	}
 
-	qInstallMessageHandler(&LogManager::messageHandler);
-
 	instance->lastCategoryFilter = QLoggingCategory::installFilter(&LogManager::filterCategory);
 
+	if (instance->lastCategoryFilter == &LogManager::filterCategory) {
+		qCFatal(logLogging) << "Quickshell's log filter has been installed twice. This is a bug.";
+		instance->lastCategoryFilter = nullptr;
+	}
+
+	qInstallMessageHandler(&LogManager::messageHandler);
+
 	qCDebug(logLogging) << "Creating offthread logger...";
 	auto* thread = new QThread();
 	instance->threadProxy.moveToThread(thread);

src/core/paths.cpp

@@ -64,7 +64,7 @@ QDir* QsPaths::baseRunDir() {
 	if (this->baseRunState == DirState::Unknown) {
 		auto runtimeDir = qEnvironmentVariable("XDG_RUNTIME_DIR");
 		if (runtimeDir.isEmpty()) {
-			runtimeDir = QString("/run/user/$1").arg(getuid());
+			runtimeDir = QString("/run/user/%1").arg(getuid());
 			qCInfo(logPaths) << "XDG_RUNTIME_DIR was not set, defaulting to" << runtimeDir;
 		}
 

src/services/pipewire/defaults.cpp

@@ -214,13 +214,24 @@ void PwDefaultTracker::setDefaultSink(PwNode* node) {
 	qCInfo(logDefaults) << "Default sink changed to" << node;
 
 	if (this->mDefaultSink != nullptr) {
-		QObject::disconnect(this->mDefaultSink, nullptr, this, nullptr);
+		// Targeted disconnect is used because this can also be the default configured sink.
+		QObject::disconnect(
+		    this->mDefaultSink,
+		    &PwBindableObject::destroying,
+		    this,
+		    &PwDefaultTracker::onDefaultSinkDestroyed
+		);
 	}
 
 	this->mDefaultSink = node;
 
 	if (node != nullptr) {
-		QObject::connect(node, &QObject::destroyed, this, &PwDefaultTracker::onDefaultSinkDestroyed);
+		QObject::connect(
+		    node,
+		    &PwBindableObject::destroying,
+		    this,
+		    &PwDefaultTracker::onDefaultSinkDestroyed
+		);
 	}
 
 	emit this->defaultSinkChanged();
@@ -244,13 +255,24 @@ void PwDefaultTracker::setDefaultSource(PwNode* node) {
 	qCInfo(logDefaults) << "Default source changed to" << node;
 
 	if (this->mDefaultSource != nullptr) {
-		QObject::disconnect(this->mDefaultSource, nullptr, this, nullptr);
+		// Targeted disconnect is used because this can also be the default configured source.
+		QObject::disconnect(
+		    this->mDefaultSource,
+		    &PwBindableObject::destroying,
+		    this,
+		    &PwDefaultTracker::onDefaultSourceDestroyed
+		);
 	}
 
 	this->mDefaultSource = node;
 
 	if (node != nullptr) {
-		QObject::connect(node, &QObject::destroyed, this, &PwDefaultTracker::onDefaultSourceDestroyed);
+		QObject::connect(
+		    node,
+		    &PwBindableObject::destroying,
+		    this,
+		    &PwDefaultTracker::onDefaultSourceDestroyed
+		);
 	}
 
 	emit this->defaultSourceChanged();
@@ -274,7 +296,13 @@ void PwDefaultTracker::setDefaultConfiguredSink(PwNode* node) {
 	qCInfo(logDefaults) << "Default configured sink changed to" << node;
 
 	if (this->mDefaultConfiguredSink != nullptr) {
-		QObject::disconnect(this->mDefaultConfiguredSink, nullptr, this, nullptr);
+		// Targeted disconnect is used because this can also be the default sink.
+		QObject::disconnect(
+		    this->mDefaultConfiguredSink,
+		    &PwBindableObject::destroying,
+		    this,
+		    &PwDefaultTracker::onDefaultConfiguredSinkDestroyed
+		);
 	}
 
 	this->mDefaultConfiguredSink = node;
@@ -282,7 +310,7 @@ void PwDefaultTracker::setDefaultConfiguredSink(PwNode* node) {
 	if (node != nullptr) {
 		QObject::connect(
 		    node,
-		    &QObject::destroyed,
+		    &PwBindableObject::destroying,
 		    this,
 		    &PwDefaultTracker::onDefaultConfiguredSinkDestroyed
 		);
@@ -309,7 +337,13 @@ void PwDefaultTracker::setDefaultConfiguredSource(PwNode* node) {
 	qCInfo(logDefaults) << "Default configured source changed to" << node;
 
 	if (this->mDefaultConfiguredSource != nullptr) {
-		QObject::disconnect(this->mDefaultConfiguredSource, nullptr, this, nullptr);
+		// Targeted disconnect is used because this can also be the default source.
+		QObject::disconnect(
+		    this->mDefaultConfiguredSource,
+		    &PwBindableObject::destroying,
+		    this,
+		    &PwDefaultTracker::onDefaultConfiguredSourceDestroyed
+		);
 	}
 
 	this->mDefaultConfiguredSource = node;
@@ -317,7 +351,7 @@ void PwDefaultTracker::setDefaultConfiguredSource(PwNode* node) {
 	if (node != nullptr) {
 		QObject::connect(
 		    node,
-		    &QObject::destroyed,
+		    &PwBindableObject::destroying,
 		    this,
 		    &PwDefaultTracker::onDefaultConfiguredSourceDestroyed
 		);