Comment 2 for bug 941351

StacktraceTop:
 g_assertion_message (domain=<optimized out>, file=<optimized out>, line=<optimized out>, func=0x7ff2f0ace0e0 "rhythmdb_property_model_set_query_model_internal", message=0x38aac50 "assertion failed: (rhythmdb_property_model_iter_n_children (GTK_TREE_MODEL (model), NULL) == 1)") at /build/buildd/glib2.0-2.31.18/./glib/gtestutils.c:1860
 g_assertion_message_expr (domain=0x7ff2f0acfc2e "RhythmDB", file=0x7ff2f0acd83b "rhythmdb-property-model.c", line=379, func=0x7ff2f0ace0e0 "rhythmdb_property_model_set_query_model_internal", expr=<optimized out>) at /build/buildd/glib2.0-2.31.18/./glib/gtestutils.c:1871
 rhythmdb_property_model_set_query_model_internal (query_model=0x288ecb0, model=0x2ef1550) at rhythmdb-property-model.c:379
 rhythmdb_property_model_set_property (object=<optimized out>, prop_id=<optimized out>, value=<optimized out>, pspec=0x22f89e0) at rhythmdb-property-model.c:452
 object_set_property (nqueue=0x7ff2c40034b0, value=0x7fffbf315c20, pspec=0x22f89e0, object=0x2ef1550) at /build/buildd/glib2.0-2.31.18/./gobject/gobject.c:1352