0xb60faf02 in TagLib::FileRef::operator= () from /usr/lib/libtag.so.1
(gdb) bt
#0  0xb60faf02 in TagLib::FileRef::operator= () from /usr/lib/libtag.so.1
#1  0xb7cf8f4b in MetaBundle::readUniqueId (this=0x87d3040, fileref=0x0) at metabundle.cpp:1539
#2  0xb7cf84a5 in MetaBundle::save (this=0x87d3040, fileref=0x0) at metabundle.cpp:1416
#3  0xb7de7389 in TagDialogWriter::doJob (this=0x83ef698) at tagdialog.cpp:1201
#4  0xb7deda8c in ThreadWeaver::Thread::run (this=0x8311ef8) at threadweaver.cpp:297
#5  0xb65bd615 in QThreadInstance::start () from /usr/lib/qt/lib/libqt-mt.so.3
#6  0xb5ffc20e in start_thread () from /lib/tls/libpthread.so.0
#7  0xb5d9d0de in clone () from /lib/tls/libc.so.6