From d0f071b625718348fb3f5ffaf71f037ee748cc30 Mon Sep 17 00:00:00 2001
From: Vladimir Golovnev <glassez@yandex.ru>
Date: Wed, 26 Jul 2023 20:25:10 +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 c1251181d..b2f75d3fe 100644
--- a/src/gui/transferlistwidget.cpp
+++ b/src/gui/transferlistwidget.cpp
@@ -254,6 +254,16 @@ 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());
@@ -264,11 +274,13 @@ 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->isSeed())
@@ -872,9 +884,13 @@ 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);
     }
@@ -883,11 +899,13 @@ 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;
@@ -902,8 +920,7 @@ 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)
@@ -924,7 +941,8 @@ 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 51caeee7d..a8e433d21 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;