Seg Fault when trying to display a QMessageBox

TL00

OS is Ubuntu 10.10 amd64 and QT 4.7 SDK installed. My app is trying to display a message box but fails with a seg fault if I change the default theme in Ubuntu from Ambiance to Clearlooks. Works fine using Ambiance. Any ideas on how to fix this?
output from terminal:
(<unknown>:2076): GdkPixbuf-WARNING **: Bug! loader 'png' didn't set an error on failure

(<unknown>:2076): Gtk-WARNING **: Error loading theme icon 'dialog-error' for stock: Internal error: Image loader module 'png' failed to complete an operation, but didn't give a reason for the failure

(<unknown>:2076): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed

** (<unknown>:2076): CRITICAL **: clearlooks_style_draw_render_icon: assertion `base_pixbuf != NULL' failed

(<unknown>:2076): Gtk-CRITICAL **: IA__gtk_style_render_icon: assertion `pixbuf != NULL' failed

(<unknown>:2076): GdkPixbuf-CRITICAL **: gdk_pixbuf_get_pixels: assertion `GDK_IS_PIXBUF (pixbuf)' failed

(<unknown>:2076): GdkPixbuf-CRITICAL **: gdk_pixbuf_get_width: assertion `GDK_IS_PIXBUF (pixbuf)' failed

(<unknown>:2076): GdkPixbuf-CRITICAL **: gdk_pixbuf_get_height: assertion `GDK_IS_PIXBUF (pixbuf)' failed

Program received signal SIGSEGV, Segmentation fault.

stukdev

Have you installed qt sdk 2010.05.1 or 2010.05? Because the second give me the error message you posted!

mcosta

can you post your code?

The messages you post are from GTK/GDK. Qt shouldn't use them.

TL00

Yes I installed qt-sdk-linux-x86_64-opensource-2010.05.1.bin.

Here's the code:
@
QMessageBox::critical(0, qApp->tr("Cannot open database"),
qApp->tr("Unable to establish a database connection.\n"
"\n"
"Click Cancel to exit."), QMessageBox::Cancel);
@

Here's the backtrace:

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff73c3421 in QGtkPainter::getIcon(char const*, GtkIconSize) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
(gdb) backtrace full
#0 0x00007ffff73c3421 in QGtkPainter::getIcon(char const*, GtkIconSize) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#1 0x00007ffff73b26f2 in QGtkStyle::standardIconImplementation(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#2 0x00007ffff77032c3 in QGtkStyle::qt_metacall(QMetaObject::Call, int, void**) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#3 0x00007ffff6a8adcd in QMetaMethod::invoke(QObject*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) const () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtCore.so.4
No symbol table info available.
#4 0x00007ffff6a8cb26 in QMetaObject::invokeMethod(QObject*, char const*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtCore.so.4
No symbol table info available.
#5 0x00007ffff7327041 in QStyle::standardIcon(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#6 0x00007ffff7543a5f in QMessageBoxPrivate::standardIcon(QMessageBox::Icon, QMessageBox*) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#7 0x00007ffff754507d in QMessageBox::setIcon(QMessageBox::Icon) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#8 0x00007ffff7546460 in QMessageBox::QMessageBox(QMessageBox::Icon, QString const&, QString const&, QFlagsQMessageBox::StandardButton, QWidget*, QFlagsQt::WindowType) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#9 0x00007ffff75469b8 in showNewMessageBox(QWidget*, QMessageBox::Icon, QString const&, QString const&, QFlagsQMessageBox::StandardButton, QMessageBox::StandardButton) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#10 0x00007ffff7546b2f in QMessageBox::critical(QWidget*, QString const&, QString const&, QFlagsQMessageBox::StandardButton, QMessageBox::StandardButton) () from /home/tonyl/dev/Mtran-build-desktop/lib/libQtGui.so.4
No symbol table info available.
#11 0x00000000004118d1 in createDbConnection (db=...) at ../Mtran/db.cpp:38
No locals.
#12 0x000000000040b9c4 in MainWindow::createConnection (this=0x7fffffffe1d0) at ../Mtran/mainwindow.cpp:459
rtn = false

[edit: code markup / chetankjain]

lyuts

Try to set this as QMEssageBox's parent, i.e. pass it as the first parameter.

@QMessageBox::critical(this, qApp->tr("Cannot open database"),
qApp->tr("Unable to establish a database connection.\n"
"\n"
"Click Cancel to exit."), QMessageBox::Cancel);@

[quote author="lyuts" date="1287664731"]Try to set this as QMEssageBox's parent, i.e. pass it as the first parameter.
[/quote]

it works with 0 parent in winxp, not sure if that could be a problem on linux

Call for Presentations - Qt World Summit

Seg Fault when trying to display a QMessageBox