Description of problem:
pyobject3 fails with the test program below on gdk_screen_get_n_monitors.

Version-Release number of selected component (if applicable):
pygobject3-3.2.0-1.fc17.x86_64

How reproducible:
100%

Steps to Reproduce:
$ python -c "from gi.repository import Gdk; Gdk.init([]); s=Gdk.Screen(); print s.get_n_monitors()"

Note: same results with or without the Gdk.init call, or if using Gdk.init(sys.argv)

Actual results:
$ python -c "from gi.repository import Gdk; Gdk.init([]); s=Gdk.Screen(); print s.get_n_monitors()"
Segmentation fault (core dumped)

Expected results:
print 2 like example below with pygtk.

Additional info:
The equivalent pygtk works:

$ python -c "import gtk; s=gtk.gdk.Screen(); print s.get_n_monitors()"
[cut some warnings]
2

Also the equivalent c code works:
#include <stdio.h>
#include <gdk/gdk.h>

int main(int argc, char **argv)
{
    GdkScreen *screen;

    gdk_init(&argc, &argv);

    screen = gdk_screen_get_default();

    printf("%d\n", gdk_screen_get_n_monitors(screen));
    return 0;
}

And so does the equivalent 

Stack trace:
#0  0x0000000000000000 in ?? ()
#1  0x0000003b07e05e90 in ffi_call_unix64 () at ../src/x86/unix64.S:75
#2  0x0000003b07e058a0 in ffi_call (cif=cif@entry=0x7fffffffd120, fn=fn@entry=
    0x31be028bf0 <gdk_screen_get_n_monitors>, rvalue=rvalue@entry=0x7fffffffd100, avalue=avalue@entry=
    0x7fffffffd040) at ../src/x86/ffi64.c:486
#3  0x0000003b23c0a584 in g_callable_info_invoke (info=info@entry=0x796630, function=0x31be028bf0, 
    in_args=in_args@entry=0x74b850, n_in_args=n_in_args@entry=1, out_args=out_args@entry=0x0, 
    n_out_args=n_out_args@entry=0, return_value=return_value@entry=0x7fffffffd2e0, 
    is_method=is_method@entry=1, throws=0, error=error@entry=0x7fffffffd298)
    at girepository/gicallableinfo.c:610
#4  0x0000003b23c0b8eb in g_function_info_invoke (info=0x796630, in_args=0x74b850, n_in_args=1, 
    out_args=0x0, n_out_args=0, return_value=return_value@entry=0x7fffffffd2e0, error=error@entry=
    0x7fffffffd298) at girepository/gifunctioninfo.c:274
#5  0x00007ffff1846c41 in _invoke_callable (callable_info=<optimized out>, cache=0x808d80, state=
    0x7fffffffd2a0) at pygi-invoke.c:52
#6  _wrap_g_callable_info_invoke (self=0x7ffff003c518, py_args=<optimized out>, kwargs=<optimized out>)
    at pygi-invoke.c:633
#7  0x0000003b18edc1e0 in ext_do_call (nk=0, na=<optimized out>, flags=<optimized out>, pp_stack=
    0x7fffffffd4f8, func=<built-in method invoke of gi.FunctionInfo object at remote 0x7ffff003c518>)
    at /usr/src/debug/Python-2.7.3/Python/ceval.c:4408
#8  PyEval_EvalFrameEx (f=f@entry=
    Frame 0x7e62a0, for file /usr/lib64/python2.7/site-packages/gi/types.py, line 43, in function (args=(<Screen at remote 0x7ffff0532f50>,), kwargs={}), throwflag=throwflag@entry=0)
    at /usr/src/debug/Python-2.7.3/Python/ceval.c:2779
#9  0x0000003b18eddb2f in PyEval_EvalCodeEx (co=<optimized out>, globals=<optimized out>, 
    locals=locals@entry=0x0, args=<optimized out>, argcount=argcount@entry=1, kws=0x6d16e0, kwcount=0, 
    defs=0x0, defcount=0, closure=(<cell at remote 0x7ffff003b718>,))
    at /usr/src/debug/Python-2.7.3/Python/ceval.c:3330
#10 0x0000003b18edc123 in fast_function (nk=<optimized out>, na=1, n=<optimized out>, pp_stack=
    0x7fffffffd7a8, func=<function at remote 0x7ffff003d500>)
    at /usr/src/debug/Python-2.7.3/Python/ceval.c:4194
#11 call_function (oparg=<optimized out>, pp_stack=0x7fffffffd7a8)
    at /usr/src/debug/Python-2.7.3/Python/ceval.c:4119
#12 PyEval_EvalFrameEx (f=f@entry=Frame 0x6d1560, for file <string>, line 1, in <module> (), 
    throwflag=throwflag@entry=0) at /usr/src/debug/Python-2.7.3/Python/ceval.c:2740
#13 0x0000003b18eddb2f in PyEval_EvalCodeEx (co=co@entry=0x7ffff7efe9b0, globals=globals@entry=
    {'__builtins__': <module at remote 0x7ffff7f7aad0>, '__package__': None, 'sys': <module at remote 0x7ffff7f7ab78>, 's': <Screen at remote 0x7ffff0532f50>, '__name__': '__main__', 'Gdk': <DynamicModule(_overrides_module=<module at remote 0x7ffff052eb40>, _namespace='Gdk', _introspection_module=<IntrospectionModule(_namespace='Gdk', DragContext=<GObjectMeta(__module__='gi.repository.Gdk', get_actions=<function at remote 0x7ffff0030de8>, get_device=<function at remote 0x7ffff0030ed8>, get_source_window=<function at remote 0x7ffff003a0c8>, list_targets=<function at remote 0x7ffff003a1b8>, get_dest_window=<function at remote 0x7ffff0030e60>, set_device=<function at remote 0x7ffff003a230>, get_selected_action=<function at remote 0x7ffff003a050>, get_protocol=<function at remote 0x7ffff0030f50>, get_suggested_action=<function at remote 0x7ffff003a140>, __gtype__=<gobject.GType at remote 0x7ffff7f3a648>, __info__=<ObjectInfo at remote 0x7ffff0037dd0>, __doc__=None) at remote 0x7e3b00>, EventSetting=<StructMeta(send_e...(truncated), locals=locals@entry=
    {'__builtins__': <module at remote 0x7ffff7f7aad0>, '__package__': None, 'sys': <module at remote 0x7ffff7f7ab78>, 's': <Screen at remote 0x7ffff0532f50>, '__name__': '__main__', 'Gdk': <DynamicModule(_overrides_module=<module at remote 0x7ffff052eb40>, _namespace='Gdk', _introspection_module=<IntrospectionModule(_namespace='Gdk', DragContext=<GObjectMeta(__module__='gi.repository.Gdk', get_actions=<function at remote 0x7ffff0030de8>, get_device=<function at remote 0x7ffff0030ed8>, get_source_window=<function a---Type <return> to continue, or q <return> to quit---