tf's review

VeriFIT · Sep 28, 2023 · 03e911d · 03e911d
1 parent a375fd1
commit 03e911d
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/nfa/intersection.cc b/src/nfa/intersection.cc
@@ -40,6 +40,9 @@ Nfa intersection(const Nfa& lhs, const Nfa& rhs, const Symbol first_epsilon, Pro
         return lhs.final.contains(lhs_state) && rhs.final.contains(rhs_state);
     };
 
+    if (lhs.final.empty() || lhs.initial.empty() || rhs.initial.empty() || rhs.final.empty())
+        return Nfa{};
+
     return algorithms::product(lhs, rhs, both_final, first_epsilon, prod_map);
 }