SEGV in accessible_text_handle_method with no selection
When there is a Gtk.Text that has no selection, there is a segmentation violation when orca is on:
received signal SIGSEGV, Segmentation fault.
#0 0x00007ffff71bbf9a in accessible_text_handle_method (connection=<optimized out>, sender=<optimized out>, object_path=<optimized out>, interface_name=<optimized out>, method_name=<optimized out>, parameters=0x7fffe80071e0, invocation=0x7fffe80170a0, user_data=0x555556f27350) at ../gtk/a11y/gtkatspitext.c:257
start = <optimized out>
end = <optimized out>
num = 0
n_ranges = 140737488344032
ranges = 0x0
self = 0x555556f27350
accessible = 0x555556f26eb0
accessible_text = 0x555556f26eb0