minor check (trapped from time to time)

git-svn-id: https://svn.inf.ethz.ch/svn/lecturers/a2/trunk@7178 8c9fc860-2736-0410-a75d-ab315db34111

source/WMProcessInfo.Mod

@@ -252,7 +252,7 @@ TYPE
 				sw.Reset; ProcessInfo.WriteMode(processes[i].mode, sw); sw.Get(str); SetText(i, 4, str);
 
 				(* PC - 5 *)
-				IF mod # NIL THEN DEC(pc, ADDRESSOF(mod.code[0])) END;
+				IF (mod # NIL) & (mod.code # NIL) THEN DEC(pc, ADDRESSOF(mod.code[0])) END;
 				Strings.IntToStr(SYSTEM.VAL (LONGINT, pc), str); SetText(i, 5, str);
 
 				(* active object type - 6 *)