From 88a95348f6a89b595a44d1d7226db95c80fc8242 Mon Sep 17 00:00:00 2001
From: Alisa Sireneva <me@purplesyringa.moe>
Date: Tue, 10 Dec 2024 19:19:09 +0300
Subject: [PATCH] Use length prefix in default `Hasher::write_str`

Using a 0xFF trailer is only correct for bytewise hashes. A generic
`Hasher` is not necessarily bytewise, so use a length prefix in the
default implementation instead.
---
 library/core/src/hash/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/library/core/src/hash/mod.rs b/library/core/src/hash/mod.rs
index 84bbf985e8be4..35b5eed48524f 100644
--- a/library/core/src/hash/mod.rs
+++ b/library/core/src/hash/mod.rs
@@ -549,8 +549,8 @@ pub trait Hasher {
     #[inline]
     #[unstable(feature = "hasher_prefixfree_extras", issue = "96762")]
     fn write_str(&mut self, s: &str) {
+        self.write_length_prefix(s.len());
         self.write(s.as_bytes());
-        self.write_u8(0xff);
     }
 }