QFileDialog The program has unexpectedly finished.

SGaist

Can you show a stack trace of your crash ?

Linux BABU

Hi,

i am new to qt where i can find this stack trace on qt creator.

thank you

Flotisable

@Linux-BABU
if you are using qtcreator, just press F5 to run the program in debug mode, when your program crash, it will show the stack trace on the bottom

Linux BABU

Hi

This is my stack trace

1 ?? 0x7fffe0320526
2 ?? 0x7fffe032762e
3 ?? 0x7fffdb8448db
4 ?? 0x7fffdb8448f9
5 g_main_context_dispatch 0x7ffff1615ce5
6 ?? 0x7ffff1616048
7 g_main_context_iteration 0x7ffff16160ec
8 QEventDispatcherGlib::processEvents(QFlagsQEventLoop::ProcessEventsFlag) 0x7ffff47f4cbf
9 QEventLoop::exec(QFlagsQEventLoop::ProcessEventsFlag) 0x7ffff47a29ca
10 QCoreApplication::exec() 0x7ffff47aa9f4
11 main main.cpp 10 0x40e488

Thank you

SGaist

Which Linux distribution are you on ?

Linux BABU

@SGaist

ubuntu 14.04 64bit

kd_wala

Hi, I using qml FileDialog on Ubuntu 16.04, Qt 5.8 ,it have same problem with message 'Gtk-WARNING **: Invalid input string' then may app is not respond, any one can help me fix this .

jsulm

@kd_wala Most probably nobody will be able to help if you do not show your code.
My guess is that this GTK warning isn't the actual problem.

calc84maniac

I'm getting the exact same error. I'm using Qt 5.8 on Debian 8 with GNOME 3.14.1. It crashes no matter what kind of file or directory dialog I open, if I pass the DontUseNativeDialog option flag. (I would be fine with native dialog, but it seemed the ShowDirsOnly flag was being ignored, so I tried using the Qt dialogs and here we are.)

Here is a detailed stack trace from the point where a static dialog method is called:

#0  0x00007fffecf75c16 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
No symbol table info available.
#1  0x00007fffecf7a56a in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
No symbol table info available.
#2  0x00007fffec60b4bb in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
No symbol table info available.
#3  0x00007fffec60b4d9 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
No symbol table info available.
#4  0x00007ffff2949b6d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#5  0x00007ffff2949f48 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#6  0x00007ffff2949ffc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#7  0x00007ffff69b3cbf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#8  0x00007ffff69619ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#9  0x00007ffff78d5a07 in QDialog::exec() () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Widgets.so.5
No symbol table info available.
#10 0x00007ffff78e6ecd in QFileDialog::getSaveFileUrl(QWidget*, QString const&, QUrl const&, QString const&, QString*, QFlags<QFileDialog::Option>, QStringList const&) () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Widgets.so.5
No symbol table info available.
#11 0x00007ffff78e6f8a in QFileDialog::getSaveFileName(QWidget*, QString const&, QString const&, QString const&, QString*, QFlags<QFileDialog::Option>) () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Widgets.so.5
No symbol table info available.

SGaist

Hi @calc84maniac please install the debug symbol packages of these libraries, it will allow to get a better stack trace.

calc84maniac

@SGaist Sure. If you need me to get Qt 5.8.0 symbols too, please point me in the right direction since there don't seem to be any packages readily available.

#0  update_current_folder_get_info_cb (cancellable=0xaedc40, info=0x0, error=0xa7aca0, user_data=0x9df380) at /tmp/buildd/gtk+3.0-3.14.5/./gtk/gtkfilechooserwidget.c:4268
        cancelled = 1
        data = 0x9df380
        impl = 0xa1c3b0
        priv = 0x0
#1  0x00007fffecf7a56a in query_info_callback (source_object=<optimized out>, result=<optimized out>, user_data=0xaeee20) at /tmp/buildd/gtk+3.0-3.14.5/./gtk/gtkfilesystem.c:419
        async_data = 0xaeee20
        error = 0xa7aca0
        file_info = 0x0
        file = <optimized out>
#2  0x00007fffec60b4bb in g_task_return_now (task=0xaeb390) at /build/glib2.0-y6934K/glib2.0-2.42.1/./gio/gtask.c:1077
No locals.
#3  0x00007fffec60b4d9 in complete_in_idle_cb (task=0xaeb390) at /build/glib2.0-y6934K/glib2.0-2.42.1/./gio/gtask.c:1086
No locals.
#4  0x00007ffff2949b6d in g_main_dispatch (context=0x7fffe8002450) at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/gmain.c:3111
        dispatch = 0x7ffff29466c0 <g_idle_dispatch>
        prev_source = 0x7b13e0
        was_in_call = 0
        user_data = 0xaeb390
        callback = 0x7fffec60b4d0 <complete_in_idle_cb>
        cb_funcs = <optimized out>
        cb_data = 0x7fffc0001190
        need_destroy = <optimized out>
        source = 0x7fffc0001120
        current = 0x6bae40
        i = 11
#5  g_main_context_dispatch (context=context@entry=0x7fffe8002450) at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/gmain.c:3710
No locals.
#6  0x00007ffff2949f48 in g_main_context_iterate (context=context@entry=0x7fffe8002450, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/gmain.c:3781
        max_priority = 0
        timeout = 0
        some_ready = 1
        nfds = <optimized out>
        allocated_nfds = 5
        fds = 0x97b980
#7  0x00007ffff2949ffc in g_main_context_iteration (context=0x7fffe8002450, may_block=1) at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/gmain.c:3842
        retval = <optimized out>
#8  0x00007ffff69b3cbf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#9  0x00007ffff69619ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#10 0x00007ffff78d5a07 in QDialog::exec() () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Widgets.so.5
No symbol table info available.
#11 0x00007ffff78e6d5f in QFileDialog::getSaveFileUrl(QWidget*, QString const&, QUrl const&, QString const&, QString*, QFlags<QFileDialog::Option>, QStringList const&) () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Widgets.so.5
No symbol table info available.
#12 0x00007ffff78e6f8a in QFileDialog::getSaveFileName(QWidget*, QString const&, QString const&, QString const&, QString*, QFlags<QFileDialog::Option>) () from /home/user/Qt5.8.0/5.8/gcc_64/lib/libQt5Widgets.so.5
No symbol table info available.

calc84maniac

I did a little research on my own, and it looks like this is a reference counting bug in GTK+, which was fixed in GTK+ 3.15.5. The bug tracker entry is here: https://bugzilla.gnome.org/show_bug.cgi?id=725164

It appears that Firefox had to put in a workaround for this very issue: https://bugzilla.mozilla.org/show_bug.cgi?id=1166741

I'm not sure if it's worth putting a workaround in Qt or not, but it would be nice to not have segfaults.

SGaist

Since you could gather some additional hints, I'd say it would be worth double checking the bug report system to check if it's something known, if so add your findings otherwise open a new report with what you already found.