Comment 4 for bug 199245

According to the output log, it's not failing during the xrandr plugin, but rather during the keyboard plugin, and in particular in some of the xklavier function calls:

#3 0xb792dab6 in XGetWindowProperty () from /usr/lib/libX11.so.6
No symbol table info available.
#4 0xb63feda4 in xkl_engine_get_window_title (engine=0x809cd80, w=46137345) at xklavier_util.c:49
 type_ret = 3220340892
 format_ret = -1215886672
 nitems = 3220340872
 rest = 3220340840
 prop = (unsigned char *) 0xb788fff4 "\200N\003"
#5 0xb63fee1c in xkl_get_debug_window_title (engine=0x809cd80, win=46137345) at xklavier_util.c:118
 name = <value optimized out>
 sname = "NULL\000op\000ttings-daemon\000\000nel\000oard\000"
#6 0xb63f884d in xkl_engine_process_create_window_evt (engine=0x809cd80, cev=0xbff28258) at xklavier_evt.c:446
 __func__ = "xkl_engine_process_create_window_evt"
#7 0xb63f9434 in xkl_engine_filter_events (engine=0x809cd80, xev=0xbff28258) at xklavier_evt.c:52
 __func__ = "xkl_engine_filter_events"
#8 0xb641f449 in gsd_keyboard_xkb_evt_filter (xev=0xbff28258, event=0x806e158) at gsd-keyboard-xkb.c:282
No locals.

Not sure what the problem is, but it's not related to the recent xrandr changes, particularly since you report things work properly after disabling the keyboard plugin.