From 3ae6646183c9a4128de1ea7d3202ce637e1f993a Mon Sep 17 00:00:00 2001
From: Andrew Hickman <andrew.hickman1@sky.com>
Date: Mon, 28 Feb 2022 20:37:12 +0000
Subject: [PATCH] Fix out-of-bounds array index (#597)

Co-authored-by: Lucio Franco <luciofranco14@gmail.com>
---
 prost-build/src/code_generator.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/prost-build/src/code_generator.rs b/prost-build/src/code_generator.rs
index 53c0372ea..6bcbf8a95 100644
--- a/prost-build/src/code_generator.rs
+++ b/prost-build/src/code_generator.rs
@@ -963,7 +963,7 @@ fn unescape_c_escape_string(s: &str) -> Vec<u8> {
                     dst.push(octal);
                 }
                 b'x' | b'X' => {
-                    if p + 2 > len {
+                    if p + 3 > len {
                         panic!(
                             "invalid c-escaped default binary value ({}): incomplete hex value",
                             s
@@ -1074,6 +1074,12 @@ mod tests {
         );
     }
 
+    #[test]
+    #[should_panic(expected = "incomplete hex value")]
+    fn test_unescape_c_escape_string_incomplete_hex_value() {
+        unescape_c_escape_string(r#"\x1"#);
+    }
+
     #[test]
     fn test_strip_enum_prefix() {
         assert_eq!(strip_enum_prefix("Foo", "FooBar"), "Bar");