Map selected indexes to source before modify the data

Changing the data may affect the layout of the sort/filter model, which in turn may invalidate the indexes previously obtained from selection model before we process them all. Therefore, we must map all the selected indexes to source before start processing them.

PR #19372.
Closes #19359.

src/gui/transferlistwidget.cpp

@@ -253,6 +253,16 @@ QModelIndex TransferListWidget::mapToSource(const QModelIndex &index) const
     return index;
 }
 
+QModelIndexList TransferListWidget::mapToSource(const QModelIndexList &indexes) const
+{
+    QModelIndexList result;
+    result.reserve(indexes.size());
+    for (const QModelIndex &index : indexes)
+        result.append(mapToSource(index));
+
+    return result;
+}
+
 QModelIndex TransferListWidget::mapFromSource(const QModelIndex &index) const
 {
     Q_ASSERT(index.isValid());
@@ -263,11 +273,13 @@ QModelIndex TransferListWidget::mapFromSource(const QModelIndex &index) const
 void TransferListWidget::torrentDoubleClicked()
 {
     const QModelIndexList selectedIndexes = selectionModel()->selectedRows();
-    if ((selectedIndexes.size() != 1) || !selectedIndexes.first().isValid()) return;
+    if ((selectedIndexes.size() != 1) || !selectedIndexes.first().isValid())
+        return;
 
     const QModelIndex index = m_listModel->index(mapToSource(selectedIndexes.first()).row());
     BitTorrent::Torrent *const torrent = m_listModel->torrentHandle(index);
-    if (!torrent) return;
+    if (!torrent)
+        return;
 
     int action;
     if (torrent->isFinished())
@@ -871,9 +883,13 @@ QStringList TransferListWidget::askTagsForSelection(const QString &dialogTitle)
 
 void TransferListWidget::applyToSelectedTorrents(const std::function<void (BitTorrent::Torrent *const)> &fn)
 {
-    for (const QModelIndex &index : asConst(selectionModel()->selectedRows()))
+    // Changing the data may affect the layout of the sort/filter model, which in turn may invalidate
+    // the indexes previously obtained from selection model before we process them all.
+    // Therefore, we must map all the selected indexes to source before start processing them.
+    const QModelIndexList sourceRows = mapToSource(selectionModel()->selectedRows());
+    for (const QModelIndex &index : sourceRows)
     {
-        BitTorrent::Torrent *const torrent = m_listModel->torrentHandle(mapToSource(index));
+        BitTorrent::Torrent *const torrent = m_listModel->torrentHandle(index);
         Q_ASSERT(torrent);
         fn(torrent);
     }
@@ -882,11 +898,13 @@ void TransferListWidget::applyToSelectedTorrents(const std::function<void (BitTo
 void TransferListWidget::renameSelectedTorrent()
 {
     const QModelIndexList selectedIndexes = selectionModel()->selectedRows();
-    if ((selectedIndexes.size() != 1) || !selectedIndexes.first().isValid()) return;
+    if ((selectedIndexes.size() != 1) || !selectedIndexes.first().isValid())
+        return;
 
     const QModelIndex mi = m_listModel->index(mapToSource(selectedIndexes.first()).row(), TransferListModel::TR_NAME);
     BitTorrent::Torrent *const torrent = m_listModel->torrentHandle(mi);
-    if (!torrent) return;
+    if (!torrent)
+        return;
 
     // Ask for a new Name
     bool ok = false;
@@ -901,8 +919,7 @@ void TransferListWidget::renameSelectedTorrent()
 
 void TransferListWidget::setSelectionCategory(const QString &category)
 {
-    for (const QModelIndex &index : asConst(selectionModel()->selectedRows()))
+    applyToSelectedTorrents([&category](BitTorrent::Torrent *torrent) { torrent->setCategory(category); });
-        m_listModel->setData(m_listModel->index(mapToSource(index).row(), TransferListModel::TR_CATEGORY), category, Qt::DisplayRole);
 }
 
 void TransferListWidget::addSelectionTag(const QString &tag)
@@ -923,7 +940,8 @@ void TransferListWidget::clearSelectionTags()
 void TransferListWidget::displayListMenu()
 {
     const QModelIndexList selectedIndexes = selectionModel()->selectedRows();
-    if (selectedIndexes.isEmpty()) return;
+    if (selectedIndexes.isEmpty())
+        return;
 
     auto *listMenu = new QMenu(this);
     listMenu->setAttribute(Qt::WA_DeleteOnClose);

src/gui/transferlistwidget.h

@@ -119,6 +119,7 @@ private slots:
 private:
     void wheelEvent(QWheelEvent *event) override;
     QModelIndex mapToSource(const QModelIndex &index) const;
+    QModelIndexList mapToSource(const QModelIndexList &indexes) const;
     QModelIndex mapFromSource(const QModelIndex &index) const;
     bool loadSettings();
     QVector<BitTorrent::Torrent *> getSelectedTorrents() const;