Tearing off popup menus from an application using Openmotif library generates a crash

Issue

Tearing off popup menus from an application using Openmotif library generates a crash.

Program terminates with similar backtrace:

#0  0x0000003f33c288cd in _XtWindowedAncestor (object=0x13096d00) at Intrinsic.c:779
779         for (object = XtParent(object); object && !XtIsWidget(object);)
(gdb) bt
#0  0x0000003f33c288cd in _XtWindowedAncestor (object=0x13096d00) at Intrinsic.c:779
#1 0x0000003f33c1d838 in XtWidgetToApplicationContext (w=0x1306edf0) at Display.c:709
#2  0x0000003f33c1433e in XtRemoveCallback (widget=0x1306edf0, name=0x606599 "destroyCallback", callback=0x3f33e5cb80 <hookObjClassRec>, closure=0x130927c8) at Callback.c:319
#3  0x00002ad4ade11997 in _XmMenuFocus (w=0x130b05c0, operation=<value optimized out>, _time=26619221) at RCMenu.c:1084
#4   0x00002ad4add67351 in PopupSharedMenuShell (cbwid=0x130b69b0, smwid=0x130b6d70, event=0x7fffdb3b2c90) at MenuShell.c:1249
#5 0x00002ad4add18f8c in Popup (cb=0x130b69b0, event=0x7fffdb3b2c90, doCascade=<value optimized out>) at CascadeB.c:1826
#6 _XmCascadingPopup (cb=0x130b69b0, event=0x7fffdb3b2c90, doCascade=<value optimized out>) at CascadeB.c:1643
#7 0x00002ad4add1995a in StartDrag (wid=0x130b69b0, event=0x7fffdb3b2c90, param=<value optimized out>, num_param=<value optimized out>) at CascadeB.c:1099
#8  0x0000003f33c485ae in HandleActions (w=<value optimized out>, event=0x7fffdb3b2c90, stateTree=0x13075550, accelWidget=<value optimized out>, procs=0x13086228, actions=0x3f33e60620) at TMstate.c:636
#9 0x0000003f33c489c9 in HandleSimpleState (w=0x130b69b0, tmRecPtr=0x130b69f8, curEventPtr=0x7fffdb3b26b0) at TMstate.c:875
#10 0x0000003f33c490cf in _XtTranslateEvent (w=0x130b69b0, event=<value optimized out>) at TMstate.c:1093
#11 0x0000003f33c2149e in XtDispatchEventToWidget (widget=0x130b69b0, event=0x7fffdb3b2c90) at Event.c:898
#12 0x0000003f33c21ba0 in _XtDefaultDispatcher (event=0x7fffdb3b2c90) at Event.c:1359
#13 0x0000003f33c20c4b in XtDispatchEvent (event=0x7fffdb3b2c90) at Event.c:1415
#14 0x0000003f33c20dc5 in XtAppMainLoop (app=0x1303e0e0) at Event.c:1552
#15 0x0000000000400d63 in main (argc=1, argv=0x7fffdb3b2eb8) at tear_off_menu.c:63