From 41e44d22ea378aa036fa47233dade4c88d8afa1f Mon Sep 17 00:00:00 2001
From: Vladimir Golovnev <glassez@yandex.ru>
Date: Wed, 26 Jul 2023 20:25:44 +0300
Subject: [PATCH] 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 | 36 +++++++++++++++++++++++++---------
 src/gui/transferlistwidget.h   |  1 +
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/src/gui/transferlistwidget.cpp b/src/gui/transferlistwidget.cpp
index c46b65a03..910ee4238 100644
--- a/src/gui/transferlistwidget.cpp
+++ b/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()))
-        m_listModel->setData(m_listModel->index(mapToSource(index).row(), TransferListModel::TR_CATEGORY), category, Qt::DisplayRole);
+    applyToSelectedTorrents([&category](BitTorrent::Torrent *torrent) { torrent->setCategory(category); });
 }
 
 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);
diff --git a/src/gui/transferlistwidget.h b/src/gui/transferlistwidget.h
index 205b21246..ad9b0f37b 100644
--- a/src/gui/transferlistwidget.h
+++ b/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;