JS Array shift() and unshift() do not work for QQmlSequence types

Program received signal SIGABRT, Aborted.
0x410d7b88 in __GI_raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:67
67	../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  0x410d7b88 in __GI_raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:67
#1  0x410db910 in __GI_abort () at abort.c:91
#2  0x40b9aca4 in qt_message_fatal (message=..., context=...) at global/qlogging.cpp:1283
#3  QMessageLogger::fatal (this=<optimized out>,
    msg=0x40df0f40 "ASSERT: \"%s\" in file %s, line %d") at global/qlogging.cpp:588
#4  0x40b96a1c in qt_assert (assertion=0x40588920 "!offset", file=<optimized out>,
    line=<optimized out>) at global/qglobal.cpp:2096
#5  0x4042ff0e in QV4::ArrayData::realloc (o=0x4b69d810, newType=<optimized out>,
    offset=<optimized out>, alloc=<optimized out>, enforceAttributes=false)
    at jsruntime/qv4arraydata.cpp:104
#6  0x4042fff8 in QV4::SimpleArrayData::getHeadRoom (o=<optimized out>)
    at jsruntime/qv4arraydata.cpp:192
#7  0x40431204 in QV4::SimpleArrayData::push_front (o=0x4b69d810, values=<optimized out>,
    n=<optimized out>) at jsruntime/qv4arraydata.cpp:279
#8  0x40434bfa in QV4::ArrayPrototype::method_unshift (ctx=0xbeffd368)
    at jsruntime/qv4arrayobject.cpp:554
#9  0x40443cac in QV4::BuiltinFunction::call (that=0x44962a20, callData=<optimized out>)
    at jsruntime/qv4functionobject.cpp:583
#10 0x40480f38 in call (d=0x44b00998, this=<optimized out>) at jsruntime/qv4object_p.h:270
#11 QV4::Runtime::callProperty (context=0xbeffd498, name=..., callData=...)
    at jsruntime/qv4runtime.cpp:938