From 2428c152a67c06057a98d9d29b08389cb3429c1f Mon Sep 17 00:00:00 2001
From: Stepan Koltsov <stepan.koltsov@gmail.com>
Date: Tue, 16 Feb 2021 20:44:33 +0000
Subject: [PATCH] Panic on integer overflow in Chain::remaining (#482)

Make it safer.
---
 src/buf/chain.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/buf/chain.rs b/src/buf/chain.rs
index d68bc2d0e..8a1598ccf 100644
--- a/src/buf/chain.rs
+++ b/src/buf/chain.rs
@@ -135,7 +135,7 @@ where
     U: Buf,
 {
     fn remaining(&self) -> usize {
-        self.a.remaining() + self.b.remaining()
+        self.a.remaining().checked_add(self.b.remaining()).unwrap()
     }
 
     fn chunk(&self) -> &[u8] {
@@ -178,7 +178,10 @@ where
     U: BufMut,
 {
     fn remaining_mut(&self) -> usize {
-        self.a.remaining_mut() + self.b.remaining_mut()
+        self.a
+            .remaining_mut()
+            .checked_add(self.b.remaining_mut())
+            .unwrap()
     }
 
     fn chunk_mut(&mut self) -> &mut UninitSlice {