QFileDialog: Fix a crash occurring when deleting a file

A crash has been observed on Windows in the use case below:
1) In a non-native QFileDialog, select a file and press "Del" key to
delete it, and a warning message box appears for user to confirm the
deletion.
2) Delete the file in the Windows Explorer.
3) Click "Yes" on the warning message box, a crash happens
In QFileDialog::_q_deleteCurrent(), use QPersistentModelIndex
instead of QModelIndex to ensure that the index is valid to be
deleted. The change is intended to fix .

The patch is to use QPersistentModelIndex instead of QModelIndex
in QFileDialog::_q_deleteCurrent() to ensure that the index is
valid to be deleted.

Change-Id: I8959124dc071f7cf0ab47f954d611211a789978d
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index b638adeaec..b953c63569 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -3417,7 +3417,7 @@ void QFileDialogPrivate::_q_deleteCurrent()
 
     QModelIndexList list = qFileDialogUi->listView->selectionModel()->selectedRows();
     for (int i = list.count() - 1; i >= 0; --i) {
-        QModelIndex index = list.at(i);
+        QPersistentModelIndex index = list.at(i);
         if (index == qFileDialogUi->listView->rootIndex())
             continue;
 
@@ -3443,12 +3443,15 @@ void QFileDialogPrivate::_q_deleteCurrent()
                                       QMessageBox::Yes | QMessageBox::No, QMessageBox::No) == QMessageBox::No)
             return;
 
+        // the event loop has run, we have to validate if the index is valid because the model might have removed it.
+        if (!index.isValid())
+            return;
+
 #else
         if (!(p & QFile::WriteUser))
             return;
 #endif // QT_CONFIG(messagebox)
 
-        // the event loop has run, we can NOT reuse index because the model might have removed it.
         if (isDir) {
             if (!removeDirectory(filePath)) {
 #if QT_CONFIG(messagebox)