From 799ff26e71c03aec171fa0eb94abec8e11e3549e Mon Sep 17 00:00:00 2001
From: wborgeaud <williamborgeaud@gmail.com>
Date: Mon, 15 Nov 2021 19:46:28 +0100
Subject: [PATCH] Avoid underflow when checking the length of `terms`

---
 src/util/reducing.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/util/reducing.rs b/src/util/reducing.rs
index 1cddc3e7..f700a6ff 100644
--- a/src/util/reducing.rs
+++ b/src/util/reducing.rs
@@ -107,7 +107,7 @@ impl<const D: usize> ReducingFactorTarget<D> {
         let l = terms.len();
 
         // For small reductions, use an arithmetic gate.
-        if l - 1 <= ArithmeticExtensionGate::<D>::new_from_config(&builder.config).num_ops {
+        if l <= ArithmeticExtensionGate::<D>::new_from_config(&builder.config).num_ops + 1 {
             let terms_ext = terms
                 .iter()
                 .map(|&t| builder.convert_to_ext(t))
@@ -162,7 +162,7 @@ impl<const D: usize> ReducingFactorTarget<D> {
         let l = terms.len();
 
         // For small reductions, use an arithmetic gate.
-        if l - 1 <= ArithmeticExtensionGate::<D>::new_from_config(&builder.config).num_ops {
+        if l <= ArithmeticExtensionGate::<D>::new_from_config(&builder.config).num_ops + 1 {
             return self.reduce_arithmetic(terms, builder);
         }