File dialog segfaults when extra choice is used

[robxnano]

The QFileDialog used by xdg-desktop-portal-lxqt segfaults on close when an extra combo or check box is added to it through the portal's 'choice' option.

Affected Versions:

0.2.0 from Lubuntu 22.10, 0.3.0 from Lubuntu 22.04 backports

Steps to reproduce:

This can be reproduced using Gnome's Text Editor. apt-get install gnome-text-editor && export GDK_DEBUG=portals && gnome-text-editor In the application, click on the Open button and then the folder icon. When you click the Open button in the file dialog, xdg-desktop-portal-lxqt crashes. The application doesn't receive the details of the selected file.

Backtrace:

GNU gdb (Ubuntu 12.1-3ubuntu2) 12.1
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Reading symbols from /usr/libexec/xdg-desktop-portal-lxqt...
(No debugging symbols found in /usr/libexec/xdg-desktop-portal-lxqt)
(gdb) run
Starting program: /usr/libexec/xdg-desktop-portal-lxqt 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff2b0f6c0 (LWP 13849)]
[New Thread 0x7ffff0b116c0 (LWP 13850)]
xdp-lxqt: Desktop portal registered successfully
xdp-lxqt-file-chooser: OpenFile called with parameters:
xdp-lxqt-file-chooser:     handle:  "/org/freedesktop/portal/desktop/request/1_213/gtk356050825"
xdp-lxqt-file-chooser:     parent_window:  "x11:2c0000f"
xdp-lxqt-file-chooser:     title:  "Open Source"
xdp-lxqt-file-chooser:     options:  QMap(("accept_label", QVariant(QString, "_Open"))("choices", QVariant(QDBusArgument, ))("directory", QVariant(bool, false))("filters", QVariant(QDBusArgument, ))("modal", QVariant(bool, true))("multiple", QVariant(bool, false)))
[New Thread 0x7fffebfff6c0 (LWP 13910)]
[New Thread 0x7fffeb7fe6c0 (LWP 13911)]
[New Thread 0x7fffea3316c0 (LWP 13912)]
[New Thread 0x7fffe9b306c0 (LWP 13913)]
[New Thread 0x7fffe932f6c0 (LWP 13914)]
[Thread 0x7fffe932f6c0 (LWP 13914) exited]
[Thread 0x7fffea3316c0 (LWP 13912) exited]
[Thread 0x7fffe9b306c0 (LWP 13913) exited]
[New Thread 0x7fffe9b306c0 (LWP 13915)]
[New Thread 0x7fffe932f6c0 (LWP 13916)]
[Thread 0x7fffe932f6c0 (LWP 13916) exited]
[New Thread 0x7fffe932f6c0 (LWP 13917)]
[Thread 0x7fffe932f6c0 (LWP 13917) exited]

Thread 1 "xdg-desktop-por" received signal SIGSEGV, Segmentation fault.
0x0000555555567238 in QScopedPointerDeleter<QWidget>::cleanup(QWidget*) ()
(gdb) bt
#0  0x0000555555567238 in QScopedPointerDeleter<QWidget>::cleanup(QWidget*) ()
#1  0x0000555555563bd3 in QScopedPointer<QWidget, QScopedPointerDeleter<QWidget> >::~QScopedPointer() ()
#2  0x000055555555d56d in LXQt::FileChooserPortal::OpenFile(QDBusObjectPath const&, QString const&, QString const&, QString const&, QMap<QString, QVariant> const&, QMap<QString, QVariant>&) ()                                                                                                
#3  0x000055555555a6c7 in LXQt::FileChooserPortal::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) ()
#4  0x000055555555a896 in LXQt::FileChooserPortal::qt_metacall(QMetaObject::Call, int, void**) ()
#5  0x00007ffff7d8323b in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#6  0x00007ffff7d86cf0 in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007ffff7d876f2 in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#8  0x00007ffff7d89a0c in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#9  0x00007ffff6d49b30 in QObject::event(QEvent*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#10 0x00007ffff780cf32 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib/x86_64-linux-gnu/libQt5Widgets.so.5
#11 0x00007ffff6d1ce38 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#12 0x00007ffff6d1feb1 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#13 0x00007ffff6d77427 in  () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#14 0x00007ffff65294f9 in g_main_context_dispatch () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007ffff657e228 in  () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007ffff6526cb0 in g_main_context_iteration () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#17 0x00007ffff6d76aea in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
    at /lib/x86_64-linux-gnu/libQt5Core.so.5
#18 0x00007ffff6d1b7cb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#19 0x00007ffff6d23c2a in QCoreApplication::exec() () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#20 0x000055555556f17a in main ()

[tsujan]

when an extra combo or check box is added to it

Then why reporting it here? It should be reported where the code has been added.

[robxnano]

Well according to the backtrace, the segfault occurs here.

[tsujan]

~Adding any widget requires changing the code. The problem should be in the changes.~

[tsujan]

Oh, very sorry! I thought the report was made against LXQt file dialog (because of the title).

[robxnano]

Ah, I see. Sorry for the confusion!

[tsujan]

It was my fault; should have paid attention to the repository name.