modules: use scope_exit for deletion to make code more robust

src/modules/bluetooth.cpp

@@ -6,12 +6,19 @@
 #include <algorithm>
 #include <sstream>
 
+#include "util/scope_guard.hpp"
+
 namespace {
 
 using GDBusManager = std::unique_ptr<GDBusObjectManager, void (*)(GDBusObjectManager*)>;
 
 auto generateManager() -> GDBusManager {
   GError* error = nullptr;
+  waybar::util::scope_guard error_deleter([error]() {
+    if (error) {
+      g_error_free(error);
+    }
+  });
   GDBusObjectManager* manager = g_dbus_object_manager_client_new_for_bus_sync(
       G_BUS_TYPE_SYSTEM,
       GDBusObjectManagerClientFlags::G_DBUS_OBJECT_MANAGER_CLIENT_FLAGS_DO_NOT_AUTO_START,
@@ -19,7 +26,6 @@ auto generateManager() -> GDBusManager {
 
   if (error) {
     spdlog::error("g_dbus_object_manager_client_new_for_bus_sync() failed: {}", error->message);
-    g_error_free(error);
   }
 
   auto destructor = [](GDBusObjectManager* manager) {

src/modules/sni/host.cpp

@@ -2,6 +2,8 @@
 
 #include <spdlog/spdlog.h>
 
+#include "util/scope_guard.hpp"
+
 namespace waybar::modules::SNI {
 
 Host::Host(const std::size_t id, const Json::Value& config, const Bar& bar,
@@ -57,17 +59,20 @@ void Host::nameVanished(const Glib::RefPtr<Gio::DBus::Connection>& conn, const G
 
 void Host::proxyReady(GObject* src, GAsyncResult* res, gpointer data) {
   GError* error = nullptr;
+  waybar::util::scope_guard error_deleter([error]() {
+    if (error != nullptr) {
+      g_error_free(error);
+    }
+  });
   SnWatcher* watcher = sn_watcher_proxy_new_finish(res, &error);
   if (g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
     spdlog::error("Host: {}", error->message);
-    g_error_free(error);
     return;
   }
   auto host = static_cast<SNI::Host*>(data);
   host->watcher_ = watcher;
   if (error != nullptr) {
     spdlog::error("Host: {}", error->message);
-    g_error_free(error);
     return;
   }
   sn_watcher_call_register_host(host->watcher_, host->object_path_.c_str(), host->cancellable_,
@@ -76,16 +81,19 @@ void Host::proxyReady(GObject* src, GAsyncResult* res, gpointer data) {
 
 void Host::registerHost(GObject* src, GAsyncResult* res, gpointer data) {
   GError* error = nullptr;
+  waybar::util::scope_guard error_deleter([error]() {
+    if (error != nullptr) {
+      g_error_free(error);
+    }
+  });
   sn_watcher_call_register_host_finish(SN_WATCHER(src), res, &error);
   if (g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
     spdlog::error("Host: {}", error->message);
-    g_error_free(error);
     return;
   }
   auto host = static_cast<SNI::Host*>(data);
   if (error != nullptr) {
     spdlog::error("Host: {}", error->message);
-    g_error_free(error);
     return;
   }
   g_signal_connect(host->watcher_, "item-registered", G_CALLBACK(&Host::itemRegistered), data);

src/modules/sni/watcher.cpp

@@ -2,6 +2,8 @@
 
 #include <spdlog/spdlog.h>
 
+#include "util/scope_guard.hpp"
+
 using namespace waybar::modules::SNI;
 
 Watcher::Watcher()
@@ -29,6 +31,11 @@ Watcher::~Watcher() {
 
 void Watcher::busAcquired(const Glib::RefPtr<Gio::DBus::Connection>& conn, Glib::ustring name) {
   GError* error = nullptr;
+  waybar::util::scope_guard error_deleter([error]() {
+    if (error) {
+      g_error_free(error);
+    }
+  });
   g_dbus_interface_skeleton_export(G_DBUS_INTERFACE_SKELETON(watcher_), conn->gobj(),
                                    "/StatusNotifierWatcher", &error);
   if (error != nullptr) {
@@ -36,7 +43,6 @@ void Watcher::busAcquired(const Glib::RefPtr<Gio::DBus::Connection>& conn, Glib:
     if (error->code != 2) {
       spdlog::error("Watcher: {}", error->message);
     }
-    g_error_free(error);
     return;
   }
   g_signal_connect_swapped(watcher_, "handle-register-item",