Conditional jump or move depends on uninitialised value(s)

i got that one while running the qprinter autotest:

==8870== Conditional jump or move depends on uninitialised value(s)
==8870== at 0x801AA2E: inflateReset2 (inflate.c:157)
==8870== by 0x801AB0C: inflateInit2_ (inflate.c:193)
==8870== by 0x801AB82: inflateInit_ (inflate.c:206)
==8870== by 0x9A12AA8: png_create_read_struct_2 (in /usr/lib/libpng12.so.0.42.0)
==8870== by 0x9A12C79: png_create_read_struct (in /usr/lib/libpng12.so.0.42.0)
==8870== by 0x8B3B3B3: QPngHandlerPrivate::readPngHeader() (qpnghandler.cpp:356)
==8870== by 0x8B3B878: QPngHandlerPrivate::readPngImage(QImage*) (qpnghandler.cpp:427)
==8870== by 0x8B3DC3E: QPngHandler::read(QImage*) (qpnghandler.cpp:918)
==8870== by 0x8AFF20A: QImageReader::read(QImage*) (qimagereader.cpp:1129)
==8870== by 0x8AFEDE1: QImageReader::read() (qimagereader.cpp:1079)
==8870== by 0x8B180C2: QPixmapData::fromFile(QString const&, char const*, QFlags<Qt::ImageConversionFlag>) (qpixmapdata.cpp:130)
==8870== by 0x8B116E2: QPixmap::load(QString const&, char const*, QFlags<Qt::ImageConversionFlag>) (qpixmap.cpp:840)
==8870== by 0x8B0F785: QPixmap::QPixmap(QString const&, char const*, QFlags<Qt::ImageConversionFlag>) (qpixmap.cpp:259)
==8870== by 0x8DABD38: QCommonStyle::standardPixmap(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const (qcommonstyle.cpp:5417)
==8870== by 0x8E6E458: QWindowsStyle::standardPixmap(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const (qwindowsstyle.cpp:1111)
==8870== by 0x8E1E457: QPlastiqueStyle::standardPixmap(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const (qplastiquestyle.cpp:5878)
==8870== by 0x8DB4222: QCommonStyle::standardIconImplementation(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const (qcommonstyle.cpp:5959)
==8870== by 0x8E7DCD2: QWindowsStyle::standardIconImplementation(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const (qwindowsstyle.cpp:3376)
==8870== by 0x8E1E407: QPlastiqueStyle::standardIconImplementation(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const (qplastiquestyle.cpp:5869)
==8870== by 0x91FE90D: QPlastiqueStyle::qt_metacall(QMetaObject::Call, int, void**) (moc_qplastiquestyle.cpp:91)
==8870== by 0x96A5FD9: QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) (qmetaobject.cpp:237)
==8870== by 0x96A85DE: QMetaMethod::invoke(QObject*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) const (qmetaobject.cpp:1564)
==8870== by 0x96A7B51: QMetaObject::invokeMethod(QObject*, char const*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) (qmetaobject.cpp:1144)
==8870== by 0x8D76C35: QStyle::standardIcon(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const (qstyle.cpp:2279)
==8870== by 0x91143E6: QFileIconProviderPrivate::QFileIconProviderPrivate() (qfileiconprovider.cpp:128)
==8870== by 0x9114B5D: QFileIconProvider::QFileIconProvider() (qfileiconprovider.cpp:178)
==8870== by 0x90313D3: QFileInfoGatherer::QFileInfoGatherer(QObject*) (qfileinfogatherer.cpp:68)
==8870== by 0x902BBF5: QFileSystemModelPrivate::QFileSystemModelPrivate() (qfilesystemmodel_p.h:216)
==8870== by 0x90222C1: QFileSystemModel::QFileSystemModel(QObject*) (qfilesystemmodel.cpp:210)
==8870== by 0x8FD0396: QUnixPrintWidgetPrivate::QUnixPrintWidgetPrivate(QUnixPrintWidget*) (qprintdialog_unix.cpp:697)
==8870== by 0x8FD2B22: QUnixPrintWidget::QUnixPrintWidget(QPrinter*, QWidget*) (qprintdialog_unix.cpp:995)
==8870== by 0x8FCE213: QPrintDialogPrivate::init() (qprintdialog_unix.cpp:385)
==8870== by 0x8FCF481: QPrintDialog::QPrintDialog(QPrinter*, QWidget*) (qprintdialog_unix.cpp:581)
==8870== by 0x804F740: tst_QPrinter::testSetOptions() (tst_qprinter.cpp:361)
==8870== by 0x805608B: tst_QPrinter::qt_metacall(QMetaObject::Call, int, void**) (tst_qprinter.moc:118)
==8870== by 0x96A5FD9: QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) (qmetaobject.cpp:237)
==8870== by 0x96A85DE: QMetaMethod::invoke(QObject*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) const (qmetaobject.cpp:1564)
==8870== by 0x96A7B51: QMetaObject::invokeMethod(QObject*, char const*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) (qmetaobject.cpp:1144)
==8870== by 0x4CAF2F9: QMetaObject::invokeMethod(QObject*, char const*, Qt::ConnectionType, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) (qobjectdefs.h:398)
==8870== by 0x4CAC2A7: QTest::qInvokeTestMethodDataEntry(char*) (qtestcase.cpp:1223)
==8870== by 0x4CACB38: QTest::qInvokeTestMethod(char const*, char const*) (qtestcase.cpp:1318)
==8870== by 0x4CAD5A5: QTest::qInvokeTestMethods(QObject*) (qtestcase.cpp:1473)
==8870== by 0x4CADE33: QTest::qExec(QObject*, int, char**) (qtestcase.cpp:1678)
==8870== by 0x8055ED4: main (tst_qprinter.cpp:1008)
==8870==
PASS : tst_QPrinter::testSetOptions()

no idea whether the problem is libpng (1.2.42-2 from debian unstable) or whether we are calling it wrong.