Fix code style and errors

src/device/cddasongloader.cpp

@@ -197,7 +197,7 @@ void CddaSongLoader::AudioCDTagsLoaded(const QString &artist, const QString &alb
   MusicBrainzClient *musicbrainz_client = qobject_cast<MusicBrainzClient*>(sender());
   musicbrainz_client->deleteLater();
   SongList songs;
-  if (results.size() == 0) return;
+  if (results.empty()) return;
   int track_number = 1;
   for (const MusicBrainzClient::Result &ret : results) {
     Song song;

src/device/devicedatabasebackend.cpp

@@ -36,8 +36,10 @@
 
 const int DeviceDatabaseBackend::kDeviceSchemaVersion = 0;
 
-DeviceDatabaseBackend::DeviceDatabaseBackend(QObject *parent)
-    : QObject(parent) {}
+DeviceDatabaseBackend::DeviceDatabaseBackend(QObject *parent) :
+    QObject(parent),
+    db_(nullptr)
+    {}
 
 void DeviceDatabaseBackend::Init(Database* db) { db_ = db; }
 

src/device/devicelister.cpp

@@ -37,7 +37,9 @@
 
 #include "core/logging.h"
 
-DeviceLister::DeviceLister() : thread_(nullptr) {}
+DeviceLister::DeviceLister() :
+  thread_(nullptr),
+  next_mount_request_id_(0) {}
 
 DeviceLister::~DeviceLister() {
 

src/device/devicemanager.cpp

@@ -686,7 +686,7 @@ void DeviceManager::Forget(QModelIndex idx) {
   backend_->RemoveDevice(info->database_id_);
   info->database_id_ = -1;
 
-  if (!info->BestBackend() || (info->BestBackend() && !info->BestBackend()->lister_)) {  // It's not attached any more so remove it from the list
+  if (!info->BestBackend() || !info->BestBackend()->lister_) {  // It's not attached any more so remove it from the list
     beginRemoveRows(ItemToIndex(root_), idx.row(), idx.row());
     devices_.removeAll(info);
     root_->Delete(info->row);

src/device/mtploader.cpp

@@ -36,7 +36,8 @@ MtpLoader::MtpLoader(const QUrl &url, TaskManager *task_manager, CollectionBacke
       device_(device),
       url_(url),
       task_manager_(task_manager),
-      backend_(backend) {
+      backend_(backend),
+      connection_(nullptr) {
   original_thread_ = thread();
 }