From 3dd43311506ad786d5acc651906491fe90d9237e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Oliveira?= <hello@jxs.pt>
Date: Fri, 2 Aug 2024 18:01:36 +0100
Subject: [PATCH] fix underflow subtraction on read_unknown

---
 quick-protobuf/src/reader.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/quick-protobuf/src/reader.rs b/quick-protobuf/src/reader.rs
index 85ebdd6..7420eb1 100644
--- a/quick-protobuf/src/reader.rs
+++ b/quick-protobuf/src/reader.rs
@@ -555,7 +555,7 @@ impl BytesReader {
         // Meant to prevent overflowing. Comparison used is *strictly* lesser
         // since `self.end` is given by `len()`; i.e. `self.end` is 1 more than
         // highest index
-        if self.end - self.start < offset {
+        if self.end.checked_sub(self.start).ok_or(Error::Varint)? < offset {
             Err(Error::Varint)
         } else {
             self.start += offset;