Fix torrent content sorting

Fix improper sorting of the list of files contained by a torrent.
Always load all torrent content data so that the files list can be sorted properly.
Load torrent content only when needed. Don't load the list of files contained by a torrent if the list widget is not visible.

PR #15604.

src/gui/properties/propertieswidget.cpp

@@ -362,20 +362,6 @@ void PropertiesWidget::loadTorrentInfos(BitTorrent::Torrent *const torrent)
         loadUrlSeeds();
 
         m_ui->labelCreatedByVal->setText(m_torrent->creator());
-
-        // List files in torrent
-        m_propListModel->model()->setupModelData(m_torrent->info());
-
-        // Expand single-item folders recursively
-        QModelIndex currentIndex;
-        while (m_propListModel->rowCount(currentIndex) == 1)
-        {
-            currentIndex = m_propListModel->index(0, 0, currentIndex);
-            m_ui->filesList->setExpanded(currentIndex, true);
-        }
-
-        // Load file priorities
-        m_propListModel->model()->updateFilesPriorities(m_torrent->filePriorities());
     }
     // Load dynamic data
     loadDynamicData();
@@ -536,12 +522,40 @@ void PropertiesWidget::loadDynamicData()
         {
             qDebug("Updating priorities in files tab");
             m_ui->filesList->setUpdatesEnabled(false);
+
+            // Load torrent content if not yet done so
+            const bool isContentInitialized = m_propListModel->model()->hasIndex(0, 0);
+            if (!isContentInitialized)
+            {
+                // List files in torrent
+                m_propListModel->model()->setupModelData(m_torrent->info());
+                // Load file priorities
+                m_propListModel->model()->updateFilesPriorities(m_torrent->filePriorities());
+                // Update file progress/availability
+                m_propListModel->model()->updateFilesProgress(m_torrent->filesProgress());
+                m_propListModel->model()->updateFilesAvailability(m_torrent->availableFileFractions());
+
+                // Expand single-item folders recursively.
+                // This will trigger sorting and filtering so do it after all relevant data is loaded.
+                QModelIndex currentIndex;
+                while (m_propListModel->rowCount(currentIndex) == 1)
+                {
+                    currentIndex = m_propListModel->index(0, 0, currentIndex);
+                    m_ui->filesList->setExpanded(currentIndex, true);
+                }
+            }
+            else
+            {
+                // Torrent content was loaded already, only make some updates
+
                 m_propListModel->model()->updateFilesProgress(m_torrent->filesProgress());
                 m_propListModel->model()->updateFilesAvailability(m_torrent->availableFileFractions());
                 // XXX: We don't update file priorities regularly for performance
                 // reasons. This means that priorities will not be updated if
                 // set from the Web UI.
-            // PropListModel->model()->updateFilesPriorities(h.file_priorities());
+                // m_propListModel->model()->updateFilesPriorities(m_torrent->filePriorities());
+            }
+
             m_ui->filesList->setUpdatesEnabled(true);
         }
         break;