segmentation fault

libnma version: 1.8.28

In latest openSUSE Tumbleweed, when you try to connect to a Wi-Fi using PEAP, after filling all the needed infomation in the libnma wifi dialog and clicking connect button, GNOME Control Center crashes, with the following stack trace.

I did some debugging work and found out that at the point of crash, priv is NULL. BTW, this only happens after upgrading libnma to 1.8.28. 1.8.26 works well.

Thread 1 "gnome-control-c" received signal SIGSEGV, Segmentation fault.
0x00007f5e0965ae9f in stuff_changed_cb (ws=0x5562e85c04c0, user_data=0x5562e83d2a70) at ../src/nma-wifi-dialog.c:172
172		model = gtk_combo_box_get_model (GTK_COMBO_BOX (priv->sec_combo));
(gdb) bt
#0  0x00007f5e0965ae9f in stuff_changed_cb (ws=0x5562e85c04c0, user_data=0x5562e83d2a70) at ../src/nma-wifi-dialog.c:172
#1  0x00007f5e0aa2aeb2 in g_closure_invoke (closure=0x5562e89ffdd0, return_value=0x0, n_param_values=1, param_values=0x7ffd99a2c040, invocation_hint=0x7ffd99a2bfc0) at ../gobject/gclosure.c:810
#2  0x00007f5e0aa3e884 in signal_emit_unlocked_R (node=node@entry=0x5562e833e2c0, detail=detail@entry=0, instance=instance@entry=0x5562e85c04c0, emission_return=emission_return@entry=0x0, 
    instance_and_params=instance_and_params@entry=0x7ffd99a2c040) at ../gobject/gsignal.c:3641
#3  0x00007f5e0aa475ae in g_signal_emit_valist (instance=instance@entry=0x5562e85c04c0, signal_id=signal_id@entry=403, detail=detail@entry=0, var_args=var_args@entry=0x7ffd99a2c238)
    at ../gobject/gsignal.c:3397
#4  0x00007f5e0aa481c9 in g_signal_emit_by_name (instance=0x5562e85c04c0, detailed_signal=detailed_signal@entry=0x7f5e096763ba "ws-changed") at ../gobject/gsignal.c:3493
#5  0x00007f5e0966a886 in nma_ws_changed_cb (ignored=0x0, user_data=<optimized out>) at ../src/nma-ws/nma-ws.c:20
#6  stuff_changed (method=method@entry=0x5562e877bb70) at ../src/nma-ws/nma-eap-simple.c:256
#7  0x00007f5e0a93faa7 in g_idle_dispatch (source=source@entry=0x5562e8a09b10, callback=0x7f5e0966a870 <stuff_changed>, user_data=0x5562e877bb70) at ../glib/gmain.c:5654
#8  0x00007f5e0a943048 in g_main_dispatch (context=0x5562e7b8f260) at ../glib/gmain.c:3216
#9  g_main_context_dispatch (context=context@entry=0x5562e7b8f260) at ../glib/gmain.c:3881
#10 0x00007f5e0a9433d0 in g_main_context_iterate (context=context@entry=0x5562e7b8f260, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:3954
#11 0x00007f5e0a94345f in g_main_context_iteration (context=context@entry=0x5562e7b8f260, may_block=may_block@entry=1) at ../glib/gmain.c:4015
#12 0x00007f5e0ab514ed in g_application_run (application=0x5562e822a600, argc=<optimized out>, argv=<optimized out>) at ../gio/gapplication.c:2559
#13 0x00005562e659d595 in main (argc=<optimized out>, argv=<optimized out>) at ../shell/main.c:70