WIP

trealla-prolog · Apr 23, 2023 · 354c1a0 · 354c1a0
1 parent c1a85a0
commit 354c1a0
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/src/builtins.h b/src/builtins.h
@@ -177,7 +177,8 @@ inline static void set_var(query *q, const cell *c, pl_idx_t c_ctx, cell *v, pl_
 	cell *c_attrs = is_empty(&e->c) ? e->c.attrs : NULL, *v_attrs = NULL;
 	pl_idx_t c_attrs_ctx = c_attrs ? e->c.attrs_ctx : 0;
 
-	add_trail(q, c_ctx, c->var_nbr, c_attrs, c_attrs_ctx);
+	if (c_attrs || (q->cp && (c_ctx < q->st.fp)))
+		add_trail(q, c_ctx, c->var_nbr, c_attrs, c_attrs_ctx);
 
 	if (c_attrs && is_var(v)) {
 		const frame *vf = GET_FRAME(v_ctx);
@@ -219,7 +220,8 @@ inline static void reset_var(query *q, const cell *c, pl_idx_t c_ctx, cell *v, p
 	const frame *f = GET_FRAME(c_ctx);
 	slot *e = GET_SLOT(f, c->var_nbr);
 
-	//add_trail(q, c_ctx, c->var_nbr, NULL, 0);
+	if (q->cp && (c_ctx < q->st.fp))
+		add_trail(q, c_ctx, c->var_nbr, NULL, 0);
 
 	if (is_structure(v)) {
 		q->no_tco = true;