Comment 2 for bug 1725830

StacktraceTop:
 g_str_equal (v1=v1@entry=0x0, v2=<optimized out>) at ../../../../glib/ghash.c:1852
 handle_ungrab_accelerator (dbus_shell=0x55d622a29990, invocation=0x7f59f40631c0, action=38, user_data=<optimized out>) at flashback-shell.c:380
 ffi_call_unix64 () at ../src/x86/unix64.S:76
 ffi_call (cif=cif@entry=0x7ffc70d2d4b0, fn=fn@entry=0x55d620f928c0 <handle_ungrab_accelerator>, rvalue=<optimized out>, avalue=avalue@entry=0x7ffc70d2d3c0) at ../src/x86/ffi64.c:525
 g_cclosure_marshal_generic (closure=0x55d622a15aa0, return_gvalue=0x7ffc70d2d680, n_param_values=<optimized out>, param_values=<optimized out>, invocation_hint=<optimized out>, marshal_data=<optimized out>) at ../../../../gobject/gclosure.c:1490