- Extra checks:

* For incomplete protocols, better handling of dangling labels.
  * For termSubTerm better handling of NULL cases.

src/claim.c

@@ -503,6 +503,8 @@ arachne_runs_agree (const System sys, const Claimlist cl, const Termmap runs)
 	int run;
 
 	run = termmapGet (runs, role);
+	if (run != -1)
+	  {
 #ifdef DEBUG
 	    if (run < 0 || run >= sys->maxruns)
 	      {
@@ -539,6 +541,11 @@ arachne_runs_agree (const System sys, const Claimlist cl, const Termmap runs)
 	      }
 	    return rd_res;
 	  }
+	else
+	  {
+	    return NULL;
+	  }
+      }
 
       // Main
       linfo = label_find (sys->labellist, labels->term);

src/term.c

@@ -237,6 +237,7 @@ isTermEqualFn (Term term1, Term term2)
 /**
  *@param t Term to be checked for a subterm.
  *@param tsub Subterm.
+ *	Note that if t is non-null and tsub is null, it is a valid subterm.
  *@return True iff tsub is a subterm of t.
  */
 int
@@ -246,15 +247,39 @@ termSubTerm (Term t, Term tsub)
   tsub = deVar (tsub);
 
   if (isTermEqual (t, tsub))
+    {
       return 1;
-  if (realTermLeaf (t))
+    }
+  else
+    {
+      if (t == NULL)
+	{
 	  return 0;
+	}
+      else
+	{
+	  if (tsub == NULL)
+	    {
+	      return 1;
+	    }
+	  else
+	    {
+	      if (realTermLeaf (t))
+		{
+		  return 0;
+		}
+	      else
+		{
 		  if (realTermTuple (t))
 		    return (termSubTerm (TermOp1 (t), tsub)
 			    || termSubTerm (TermOp2 (t), tsub));
 		  else
 		    return (termSubTerm (TermOp (t), tsub)
 			    || termSubTerm (TermKey (t), tsub));
+		}
+	    }
+	}
+    }
 }
 
 //! See if a term is an interm of another.
@@ -1301,7 +1326,6 @@ termPrintDiff (Term t1, Term t2)
 		    }
 		}
 	    }
-
 	}
     }
 }