--- gnugo-3.9.1/patterns/dfa.c	2010-12-17 13:40:10.000000000 +0100
+++ gnugo-3.9.1-1/patterns/dfa.c	2016-06-24 23:04:02.254257947 +0200
@@ -675,12 +675,14 @@
   int c;
   int nextl, nextr;
   int state;
+  int tmp;
 
   state = gpout->last_state;
 
   /* unify the attributes of states l and r */
-  gpout->states[state].att = union_att(gpout, gpleft, gpleft->states[l].att,
-				       gpright, gpright->states[r].att);
+  tmp = union_att(gpout, gpleft, gpleft->states[l].att, gpright,
+		  gpright->states[r].att);
+  gpout->states[state].att = tmp;
 
   /* scan each possible out-transition */
   for (c = 0; c != 4; c++) {