Version:           0.2.60 (using KDE 4.4.1)
Compiler:          GCC 4.4.3 Gentoo 4.4.3 p1.0
OS:                Linux
Installed from:    Gentoo Packages

When using the Xine backend in Phonon, Phonon::MediaObject::setCurrentSource() hangs when called the second or third time (even when not calling it on the same MediaObject instance) and never returns when used in combination with a QBuffer.  The code that triggers it is this: 

Phonon::MediaObject* getMedia( const QString& fname, int pos, int size )
{
  QFile file(fname);
  file.open(QIODevice::ReadOnly);
  file.seek(pos); // A *.wav file is embedded at that
                  // position.
  Phonon::MediaObject* med = new Phonon::MediaObject(0);
  QBuffer* buf = new QBuffer(med);
  buf->setData(file.read(size)); // The embedded wav is
                                 // 'size' bytes big
  Phonon::MediaSource src(buf);

  med->setCurrentSource(src);  // <-- This hangs

  return med;
}

Most of the time, the application hangs the second time the above gets called; med->setCurrentSource(src) never returns.  When the hang occurs, there's no CPU load.

Everything works fine if I instead save file.read(size) into a new QFile and pass its fileName() to setCurrentSource().  However, in both cases, file.read(size) contains the exact same data.

Again: this only happens with the Xine backend. The GStreamer backend works fine.

I've prepared a very small example application that will trigger the bug:

  http://foss.math.aegean.gr/~realnc/qt/phonon_bug.tar.gz

The tarball includes a small data file from which the code will try to load the embedded WAV files from.  Simply "qmake; make" and then run it.  There's no GUI.


Here is a full backtrace at the moment the code hangs:

#0  0x000000300100b1fc in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
No symbol table info available.
#1  0x000000300747420b in QWaitConditionPrivate::wait (this=<value optimized out>, mutex=<value optimized out>, 
    time=<value optimized out>) at thread/qwaitcondition_unix.cpp:87
        code = <value optimized out>
#2  QWaitCondition::wait (this=<value optimized out>, mutex=<value optimized out>, time=<value optimized out>)
    at thread/qwaitcondition_unix.cpp:159
        returnValue = <value optimized out>
#3  0x00007ffff71a6de0 in Phonon::Xine::XineThread::newStream ()
    at /var/tmp/portage/media-sound/phonon-4.3.80-r1/work/phonon-4.3.80/xine/xinethread.cpp:78
        that = <value optimized out>
        locker = {{mtx = 0x7a36e1, val = 8009441}}
#4  0x00007ffff71bc669 in MediaObject (this=0x7a6d90, parent=<value optimized out>)
    at /var/tmp/portage/media-sound/phonon-4.3.80-r1/work/phonon-4.3.80/xine/mediaobject.cpp:61
No locals.
#5  0x00007ffff71c1886 in Phonon::Xine::Backend::createObject (this=<value optimized out>, c=<value optimized out>, parent=
    0x7a67b0, args=<value optimized out>)
    at /var/tmp/portage/media-sound/phonon-4.3.80-r1/work/phonon-4.3.80/xine/backend.cpp:154
No locals.
#6  0x000000301b63843f in Phonon::Factory::createMediaObject (parent=<value optimized out>)
    at /var/tmp/portage/media-sound/phonon-4.3.80-r1/work/phonon-4.3.80/phonon/factory.cpp:317
No locals.
#7  0x000000301b624e16 in Phonon::MediaObjectPrivate::createBackendObject (this=<value optimized out>)
    at /var/tmp/portage/media-sound/phonon-4.3.80-r1/work/phonon-4.3.80/phonon/mediaobject.cpp:47
No locals.
#8  0x000000301b625e7b in Phonon::MediaNodePrivate::backendObject (this=<value optimized out>)
    at /var/tmp/portage/media-sound/phonon-4.3.80-r1/work/phonon-4.3.80/phonon/medianode.cpp:63
No locals.
#9  0x000000301b623907 in Phonon::MediaObject::setCurrentSource (this=<value optimized out>, newSource=<value optimized out>)
    at /var/tmp/portage/media-sound/phonon-4.3.80-r1/work/phonon-4.3.80/phonon/mediaobject.cpp:230
        __PRETTY_FUNCTION__ = "void Phonon::MediaObject::setCurrentSource(const Phonon::MediaSource&)"
#10 0x000000000040162c in getMedia (fname=..., pos=393350, size=76844) at main.cpp:18
        file = {<QIODevice> = {<QObject> = {_vptr.QObject = 0x30078758b0, static staticMetaObject = {d = {superdata = 0x0, 
                  stringdata = 0x300760c140 "QObject", data = 0x300760c1e0, extradata = 0x300786e480}}, d_ptr = {d = 0x6d6180}, 
              static staticQtMetaObject = {d = {superdata = 0x0, stringdata = 0x3007614dc0 "Qt", data = 0x30076183e0, 
                  extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 0x300786e460, stringdata = 
    0x300761ce00 "QIODevice", data = 0x300761ce60, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 
    0x30078759c0, stringdata = 0x300761cd80 "QFile", data = 0x300761cda0, extradata = 0x0}}}
        med = 0x7a67b0
        buf = 0x7a6760
        src = {d = {d = 0x7a45b0}}
#11 0x00000000004017ca in main (argc=1, argv=0x7fffffffdba8) at main.cpp:29
        app = {<QCoreApplication> = {<QObject> = {_vptr.QObject = 0x301e61c090, static staticMetaObject = {d = {superdata = 
    0x0, stringdata = 0x300760c140 "QObject", data = 0x300760c1e0, extradata = 0x300786e480}}, d_ptr = {d = 0x605190}, 
              static staticQtMetaObject = {d = {superdata = 0x0, stringdata = 0x3007614dc0 "Qt", data = 0x30076183e0, 
                  extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 0x300786e460, stringdata = 
    0x300761df40 "QCoreApplication", data = 0x300761dfe0, extradata = 0x0}}, static self = 0x7fffffffda60}, 
          static staticMetaObject = {d = {superdata = 0x3007876980, stringdata = 0x301e2297e0 "QApplication", data = 
    0x301e229a20, extradata = 0x0}}}