Okular from git master on openSUSE Tumbleweed.

The attached PDF makes Okular crash reproducibly in Okular::AnnotationProxy(). Here's a symbolicated backtrace:

#0  0x00007ffff02a2778 in typeinfo for Okular::AnnotationProxy ()
   from /home/nate/kde/usr/lib64/libOkular5Core.so.9
#1  0x00007ffff0402a2d in SignatureModelPrivate::notifySetup (
    setupFlags=<optimized out>, pages=..., this=0x6a3560)
    at /home/nate/kde/src/okular/ui/signaturemodel.cpp:139
#2  SignatureModelPrivate::notifySetup (this=0x6a3560, pages=..., 
    setupFlags=<optimized out>) at /home/nate/kde/src/okular/ui/signaturemodel.cpp:114
#3  0x00007ffff02125ca in Okular::Document::openDocument (this=this@entry=0x57c7a0, 
    docFile=..., url=..., _mime=..., password=...)
    at /home/nate/kde/src/okular/core/document.cpp:2647
#4  0x00007ffff03586bb in Okular::Part::doOpenFile (this=this@entry=0x53f490, mimeA=..., 
    fileNameToOpenA=..., isCompressedFile=isCompressedFile@entry=0x7fffffffb657)
    at /home/nate/kde/src/okular/part.cpp:1437
#5  0x00007ffff03590a1 in Okular::Part::openFile (this=0x53f490)
    at /home/nate/kde/src/okular/part.cpp:1571
#6  0x00007ffff7f8a10d in KParts::ReadOnlyPartPrivate::openLocalFile (
    this=this@entry=0x590fd0) at /home/nate/kde/src/kparts/src/readonlypart.cpp:190
#7  0x00007ffff7f8af8e in KParts::ReadOnlyPart::openUrl (this=this@entry=0x53f490, 
    url=...) at /home/nate/kde/src/kparts/src/readonlypart.cpp:153
#8  0x00007ffff034981e in Okular::Part::openUrl (this=0x53f490, _url=..., 
    swapInsteadOfOpening=<optimized out>) at /home/nate/kde/src/okular/part.cpp:1778
#9  0x000000000041556b in Shell::openUrl (this=0x5cbe20, url=..., serializedOptions=...)
    at /home/nate/kde/src/okular/shell/shell.cpp:280
#10 0x0000000000416e70 in Shell::fileOpen (this=0x5cbe20)
    at /usr/include/qt5/QtCore/qarraydata.h:257
#11 0x000000000040f2cd in Shell::qt_static_metacall (_o=<optimized out>, 
    _id=<optimized out>, _a=0x7fffffffbc20, _c=QMetaObject::InvokeMetaMethod)
    at /home/nate/kde/build/okular/shell/okular_autogen/EWIEGA46WW/moc_shell.cpp:184
#12 0x000000000040f41c in Shell::qt_static_metacall (_o=<optimized out>, 
    _c=<optimized out>, _id=<optimized out>, _a=<optimized out>)
    at /home/nate/kde/build/okular/shell/okular_autogen/EWIEGA46WW/moc_shell.cpp:172
#13 0x00007ffff63624d8 in QMetaObject::activate (sender=0x80bca0, 
    signalOffset=<optimized out>, local_signal_index=<optimized out>, 
    argv=<optimized out>) at kernel/qobject.cpp:3809
#14 0x00007ffff6dfe852 in QAction::triggered (this=this@entry=0x80bca0, 
    _t1=<optimized out>) at .moc/moc_qaction.cpp:381
#15 0x00007ffff6e00f22 in QAction::activate (this=0x80bca0, event=<optimized out>)
    at kernel/qaction.cpp:1166
#16 0x00007ffff6e017bf in QAction::event (e=<optimized out>, this=<optimized out>)
    at kernel/qaction.cpp:1092
#17 QAction::event (this=<optimized out>, e=<optimized out>) at kernel/qaction.cpp:1081
#18 0x00007ffff6e04c62 in QApplicationPrivate::notify_helper (this=this@entry=0x438e80, 
    receiver=receiver@entry=0x80bca0, e=e@entry=0x7fffffffbf30)
    at kernel/qapplication.cpp:3703
#19 0x00007ffff6e0e1e0 in QApplication::notify (this=0x7fffffffc470, receiver=0x80bca0, 
    e=0x7fffffffbf30) at kernel/qapplication.cpp:3449
#20 0x00007ffff6337572 in QCoreApplication::notifyInternal2 (receiver=0x80bca0, 
    event=0x7fffffffbf30) at ../../include/QtCore/../../src/corelib/kernel/qobject.h:143
#21 0x00007ffff67fc9ae in QShortcutMap::dispatchEvent (this=this@entry=0x438f60, 
    e=e@entry=0x7fffffffbfe0) at kernel/qshortcutmap.cpp:700
    #22 0x00007ffff67fca8b in QShortcutMap::tryShortcut (this=this@entry=0x438f60, 
    e=e@entry=0x7fffffffbfe0) at kernel/qshortcutmap.cpp:351
#23 0x00007ffff67b24fe in QWindowSystemInterface::handleShortcutEvent (
    window=<optimized out>, window@entry=0x7fcc00, timestamp=120775117, keyCode=79, 
    modifiers=..., nativeScanCode=32, nativeVirtualKey=111, nativeModifiers=4, text=..., 
    autorepeat=false, count=1) at kernel/qwindowsysteminterface.cpp:465
#24 0x00007ffff67cee4d in QGuiApplicationPrivate::processKeyEvent (e=e@entry=0x68ffb0)
    at kernel/qguiapplication.cpp:2216
#25 0x00007ffff67d4271 in QGuiApplicationPrivate::processWindowSystemEvent (
    e=e@entry=0x68ffb0) at kernel/qguiapplication.cpp:1852
#26 0x00007ffff67af25b in QWindowSystemInterface::sendWindowSystemEvents (
    flags=flags@entry=...) at kernel/qwindowsysteminterface.cpp:1148
#27 0x00007ffff2700f4a in xcbSourceDispatch (source=<optimized out>)
    at qxcbeventdispatcher.cpp:105
#28 0x00007ffff4a950bd in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#29 0x00007ffff4a95340 in ?? () from /usr/lib64/libglib-2.0.so.0
#30 0x00007ffff4a953cf in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#31 0x00007ffff638d981 in QEventDispatcherGlib::processEvents (this=0x450fd0, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#32 0x00007ffff63360db in QEventLoop::exec (this=this@entry=0x7fffffffc390, flags=..., 
    flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#33 0x00007ffff633dd42 in QCoreApplication::exec ()
    at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#34 0x00007ffff67c7d5c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1788
#35 0x00007ffff6e04bd5 in QApplication::exec () at kernel/qapplication.cpp:2859
#36 0x000000000040d9bf in main (argc=<optimized out>, argv=<optimized out>)
    at /home/nate/kde/src/okular/shell/main.cpp:95