Use C++17 fallthrough

src/collection/collectionmodel.cpp

@@ -511,8 +511,7 @@ QString CollectionModel::DividerDisplayText(const GroupBy type, const QString &k
 
     case GroupBy_None:
     case GroupByCount:
-      // fallthrough
+      break;
-      ;
   }
   qLog(Error) << "Unknown GroupBy type" << type << "for divider key" << key;
   return QString();

src/core/mainwindow.cpp

@@ -963,7 +963,7 @@ MainWindow::MainWindow(Application *app, std::shared_ptr<SystemTrayIcon> tray_ic
       if (tray_icon_->IsSystemTrayAvailable() && tray_icon_->isVisible()) {
         break;
       }
-      // fallthrough
+      [[fallthrough]];
     case BehaviourSettingsPage::Startup_Remember:
     default: {
 

src/core/player.cpp

@@ -624,7 +624,7 @@ void Player::EngineStateChanged(const Engine::State state) {
       break;
     case Engine::Error:
       emit Error();
-      // fallthrough
+      [[fallthrough]];
     case Engine::Empty:
     case Engine::Idle:
       pause_time_ = QDateTime();

src/core/songloader.cpp

@@ -646,7 +646,7 @@ void SongLoader::EndOfStreamReached() {
       if (state_ == Finished) break;
     // It looks like a playlist, so parse it
 
-    // fallthrough
+    [[fallthrough]];
     case WaitingForData:
       // It's a playlist and we've got all the data - finish and parse it
       StopTypefindAsync(true);

src/covermanager/albumcoverchoicecontroller.cpp

@@ -217,7 +217,7 @@ QUrl AlbumCoverChoiceController::LoadCoverFromFile(Song *song) {
         SaveCoverEmbeddedAutomatic(*song, cover_file);
         return QUrl::fromLocalFile(Song::kEmbeddedCover);
       }
-      // fallthrough
+      [[fallthrough]];
     case CollectionSettingsPage::SaveCoverType_Cache:
     case CollectionSettingsPage::SaveCoverType_Album:{
       QUrl cover_url = QUrl::fromLocalFile(cover_file);
@@ -789,7 +789,7 @@ QUrl AlbumCoverChoiceController::SaveCoverAutomatic(Song *song, const AlbumCover
         break;
       }
     }
-    // fallthrough
+    [[fallthrough]];
     case CollectionSettingsPage::SaveCoverType_Cache:
     case CollectionSettingsPage::SaveCoverType_Album:{
       cover_url = SaveCoverToFileAutomatic(song, result);

src/covermanager/albumcoverloader.cpp

@@ -186,14 +186,14 @@ QString AlbumCoverLoader::CoverFilenameFromSource(const Song::Source source, con
         filename = album_id + "-" + cover_url.fileName();
         break;
       }
-      // fallthrough
+      [[fallthrough]];
     case Song::Source_Subsonic:
     case Song::Source_Qobuz:
       if (!album_id.isEmpty()) {
         filename = album_id;
         break;
       }
-      // fallthrough
+      [[fallthrough]];
     case Song::Source_Collection:
     case Song::Source_LocalFile:
     case Song::Source_CDDA:

src/osd/osdbase.cpp

@@ -306,7 +306,7 @@ void OSDBase::ShowMessage(const QString &summary, const QString &message, const
       case Native:
 #ifdef Q_OS_WIN32
         Q_UNUSED(icon)
-        // fallthrough
+        [[fallthrough]];
 #else
         if (image.isNull()) {
           ShowMessageNative(summary, message, icon, QImage());
@@ -318,7 +318,7 @@ void OSDBase::ShowMessage(const QString &summary, const QString &message, const
 #endif
       case TrayPopup:
 #ifdef Q_OS_MACOS
-        // fallthrough
+        [[fallthrough]];
 #else
         if (tray_icon_) tray_icon_->ShowPopup(summary, message, timeout_msec_);
         break;
@@ -326,7 +326,7 @@ void OSDBase::ShowMessage(const QString &summary, const QString &message, const
       case Disabled:
         if (!force_show_next_) break;
         force_show_next_ = false;
-      // fallthrough
+      [[fallthrough]];
       case Pretty:
         pretty_popup_->ShowMessage(summary, message, image);
         break;
@@ -401,7 +401,7 @@ QString OSDBase::ReplaceMessage(const MessageType type, const QString &message,
       }
       break;
 #elif defined(Q_OS_WIN32)
-      // fallthrough
+      [[fallthrough]];
 #else
       // Other OSes doesn't support native notifications.
       qLog(Debug) << "Native notifications are not supported on this OS.";

src/scrobbler/scrobblingapi20.cpp

@@ -178,7 +178,7 @@ void ScrobblingAPI20::Authenticate(const bool https) {
       messagebox_error.setTextFormat(Qt::RichText);
       messagebox_error.exec();
     }
-      // fallthrough
+      [[fallthrough]];
     case QMessageBox::Save:
       QApplication::clipboard()->setText(url.toString());
       break;

src/settings/behavioursettingspage.cpp

@@ -196,7 +196,7 @@ void BehaviourSettingsPage::Load() {
         break;
       }
       ;
-      // fallthrough
+      [[fallthrough]];
     case BehaviourSettingsPage::Startup_Remember:
     default:
       ui_->radiobutton_remember->setChecked(true);

src/tidal/tidalrequest.cpp

@@ -913,7 +913,7 @@ void TidalRequest::SongsFinishCheck(const QString &artist_id, const QString &alb
             AddSongsSearchRequest(offset_next);
             break;
           }
-          // fallthrough
+          [[fallthrough]];
         case QueryType_Artists:
         case QueryType_SearchArtists:
         case QueryType_Albums: