Version: built from v4.0rc1-622-gaeef621

When the delete key is pressed while the magnet view has focus and no magnet(s) are selected, KTorrent calls QList<QModelIndex>::front() on the list of selected rows. This makes an assert fail since the list is empty and KTorrent crashes.

Reproducible: Always

Steps to Reproduce:
1. Click and empty part of the magnet view to give it focus without selecting a magnet
2. Press the delete key
Actual Results:  
KTorrent crashes

Expected Results:  
Ignored the key press

#0  0x00000033464359e9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x00000033464370f8 in __GI_abort () at abort.c:90
#2  0x00007f90cc6a0fb3 in bt::QtMessageOutput (type=<optimized out>, msg=0x3314978 "ASSERT: \"!isEmpty()\" in file /usr/include/QtCore/qlist.h, line 282") at ../src/util/log.cpp:310
#3  0x0000003af4470f66 in qt_message_output (msgType=msgType@entry=QtFatalMsg, buf=<optimized out>) at global/qglobal.cpp:2305
#4  0x0000003af4471139 in qt_message(enum QtMsgType, const char *, typedef __va_list_tag __va_list_tag *) (msgType=msgType@entry=QtFatalMsg, msg=msg@entry=0x3af45dda38 "ASSERT: \"%s\" in file %s, line %d", ap=ap@entry=0x7fff42be1f08)
    at global/qglobal.cpp:2405
#5  0x0000003af4471944 in qFatal (msg=msg@entry=0x3af45dda38 "ASSERT: \"%s\" in file %s, line %d") at global/qglobal.cpp:2588
#6  0x0000003af4471986 in qt_assert (assertion=assertion@entry=0x490848 "!isEmpty()", file=file@entry=0x4907cb "/usr/include/QtCore/qlist.h", line=line@entry=282) at global/qglobal.cpp:2054
#7  0x0000000000445bf5 in QList<QModelIndex>::first (this=this@entry=0x7fff42be2000) at /usr/include/QtCore/qlist.h:282
#8  0x0000000000445c15 in QList<QModelIndex>::front (this=this@entry=0x7fff42be2000) at /usr/include/QtCore/qlist.h:298
#9  0x0000000000449761 in kt::MagnetView::removeMagnetDownload (this=this@entry=0x2944a00) at ../ktorrent/tools/magnetview.cpp:112
#10 0x0000000000449a73 in kt::MagnetView::keyPressEvent (this=0x2944a00, event=0x7fff42be23b0) at ../ktorrent/tools/magnetview.cpp:133
#11 0x0000003af5e18a34 in QWidget::event (this=0x2944a00, event=0x7fff42be23b0) at kernel/qwidget.cpp:8435
#12 0x0000003af5dc957c in QApplicationPrivate::notify_helper (this=this@entry=0xac7b40, receiver=receiver@entry=0x2944a00, e=e@entry=0x7fff42be23b0) at kernel/qapplication.cpp:4565
#13 0x0000003af5dd0db1 in QApplication::notify (this=this@entry=0x7fff42be3a40, receiver=0x2944a00, receiver@entry=0x2944ab0, e=e@entry=0x7fff42be23b0) at kernel/qapplication.cpp:4006
#14 0x0000000000439e2e in kt::App::notify (this=0x7fff42be3a40, receiver=0x2944ab0, event=0x7fff42be23b0) at ../ktorrent/app.cpp:99
#15 0x0000003af457c9dd in QCoreApplication::notifyInternal (this=0x7fff42be3a40, receiver=receiver@entry=0x2944ab0, event=event@entry=0x7fff42be23b0) at kernel/qcoreapplication.cpp:953
#16 0x0000003af5dc7f16 in sendSpontaneousEvent (event=event@entry=0x7fff42be23b0, receiver=receiver@entry=0x2944ab0) at ../../src/corelib/kernel/qcoreapplication.h:234
#17 qt_sendSpontaneousEvent (receiver=receiver@entry=0x2944ab0, event=event@entry=0x7fff42be23b0) at kernel/qapplication.cpp:5563
#18 0x0000003af5e63397 in QKeyMapper::sendKeyEvent (keyWidget=keyWidget@entry=0x2944ab0, grab=grab@entry=false, type=QEvent::KeyPress, code=16777223, modifiers=..., text=..., autorepeat=autorepeat@entry=false, count=1, 
    nativeScanCode=119, nativeVirtualKey=65535, nativeModifiers=16) at kernel/qkeymapper_x11.cpp:1866
#19 0x0000003af5e63739 in QKeyMapperPrivate::translateKeyEvent (this=0xb0f0c0, keyWidget=keyWidget@entry=0x2944ab0, event=event@entry=0x7fff42be2930, grab=grab@entry=false) at kernel/qkeymapper_x11.cpp:1836
#20 0x0000003af5e3f6cf in QApplication::x11ProcessEvent (this=0x7fff42be3a40, event=event@entry=0x7fff42be2930) at kernel/qapplication_x11.cpp:3556
#21 0x0000003af5e65df4 in x11EventSourceDispatch (s=s@entry=0xabb480, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:148
#22 0x0000003cb1047dc6 in g_main_dispatch (context=0xac7e90) at gmain.c:3054
#23 g_main_context_dispatch (context=context@entry=0xac7e90) at gmain.c:3630
#24 0x0000003cb1048118 in g_main_context_iterate (context=context@entry=0xac7e90, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3701
#25 0x0000003cb10481bc in g_main_context_iteration (context=0xac7e90, may_block=1) at gmain.c:3762
#26 0x0000003af45a9945 in QEventDispatcherGlib::processEvents (this=0xa80ba0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#27 0x0000003af5e65f66 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:207
#28 0x0000003af457b5af in QEventLoop::processEvents (this=this@entry=0x7fff42be2d10, flags=...) at kernel/qeventloop.cpp:149
#29 0x0000003af457b8a5 in QEventLoop::exec (this=this@entry=0x7fff42be2d10, flags=...) at kernel/qeventloop.cpp:204
#30 0x0000003af4580cc9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#31 0x0000003af5dc7d3c in QApplication::exec () at kernel/qapplication.cpp:3823
#32 0x000000000042816c in main (argc=3, argv=0x7fff42be3b78) at ../ktorrent/main.cpp:189