support for making sure exceptions are reset when they should be reset (obs from Nuno Fonseca, #159)

C/c_interface.c

@@ -1939,7 +1939,7 @@ YAP_GoalHasException(Term *t)
 X_API void
 YAP_ClearExceptions(void)
 {
-  Yap_DeleteGlobal(AtomCatch);
+  Yap_ResetExceptionTerm();
   EX = 0L;
   UncaughtThrow = FALSE;
 }

C/dbase.c

@@ -4947,35 +4947,7 @@ Term
 Yap_PopTermFromDB(DBTerm *ref)
 {
   Term t = GetDBTerm(ref);
-  DBRef *cp = ref->DBRefs;
-
-  if (cp) {
-    DBRef eref;
-
-    while ((eref = *--cp) != NIL) {
-      if (eref->Flags & LogUpdMask) {
-	LogUpdClause *cl = (LogUpdClause *)eref;
-	cl->ClRefCount--;
-	if (cl->ClFlags & ErasedMask &&
-	    !(cl->ClFlags & InUseMask) &&
-	    !(cl->ClRefCount)) {
-	  EraseLogUpdCl(cl);
-	}
-      } else {
-	LOCK(eref->lock);
-	eref->NOfRefsTo--;
-	if (eref->Flags & ErasedMask &&
-	    !(eref->Flags & InUseMask) &&
-	    eref->NOfRefsTo) {
-	  UNLOCK(eref->lock);
-	  ErDBE(eref);
-	} else {
-	  UNLOCK(eref->lock);
-	}
-      }
-    }
-  }
-  Yap_FreeCodeSpace((char *)ref);
+  ReleaseTermFromDB(ref);
   return t;
 }
 
@@ -5395,6 +5367,8 @@ p_resize_int_keys(void)
 static void 
 ReleaseTermFromDB(DBTerm *ref)
 {
+  if (!ref)
+    return;
   keepdbrefs(ref);
   ErasePendingRefs(ref);
   FreeDBSpace((char *) ref);

C/exec.c

@@ -1587,7 +1587,7 @@ Yap_InitYaamRegs(void)
   Yap_regp = &Yap_standard_regs;
 #endif
 #endif /* PUSH_REGS */
-  Yap_DeleteGlobal (AtomCatch);
+  Yap_ResetExceptionTerm ();
   Yap_PutValue (AtomBreak, MkIntTerm (0));
   TR = (tr_fr_ptr)Yap_TrailBase;
   if (Yap_AttsSize > (Yap_LocalBase-Yap_GlobalBase)/8)
@@ -1728,6 +1728,13 @@ p_reset_exception(void)
   return Yap_unify(t, ARG1);
 }
 
+void
+Yap_ResetExceptionTerm(void)
+{
+  Yap_ReleaseTermFromDB(BallTerm);
+  BallTerm = NULL;
+}
+
 static Int
 p_get_exception(void)
 {

H/Yapproto.h

@@ -176,6 +176,7 @@ Term	STD_PROTO(Yap_ExecuteCallMetaCall,(Term));
 void	STD_PROTO(Yap_InitExecFs,(void));
 Int	STD_PROTO(Yap_JumpToEnv,(Term));
 Term	STD_PROTO(Yap_RunTopGoal,(Term));
+void	STD_PROTO(Yap_ResetExceptionTerm,(void));
 Int	STD_PROTO(Yap_execute_goal,(Term, int, Term));
 int	STD_PROTO(Yap_exec_absmi,(int));
 void	STD_PROTO(Yap_trust_last,(void));

packages/chr

@@ -1 +1 @@
-Subproject commit f6a79007615bf46dc79712c41d61289834f28ba3
+Subproject commit c325e4564bb8d4e32c27f2061df85f13d315974e

packages/jpl

@@ -1 +1 @@
-Subproject commit eb6d27251c2548c25e6d37fff2a27a014caaa7aa
+Subproject commit a2d2f03107eecd45462cd61a678035132cf06326

packages/plunit/examples/simple.pl

@@ -30,3 +30,4 @@ test(append) :-
 	X == "aapnoot".
 
 :- end_tests(lists).
+