From 9f042405061ffdd3b49adcffd233e4bf2407f1ed Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Thu, 29 Feb 2024 14:12:30 +0100
Subject: [PATCH] Avoid panic branch in `EscapeDefault::backslash` and
 `EscapeDebug::backslash`.

---
 library/core/src/escape.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/library/core/src/escape.rs b/library/core/src/escape.rs
index 143e277283e2c..45dc79ad36c3d 100644
--- a/library/core/src/escape.rs
+++ b/library/core/src/escape.rs
@@ -3,6 +3,7 @@
 use crate::ascii;
 use crate::num::NonZero;
 use crate::ops::Range;
+use crate::ptr;
 
 const HEX_DIGITS: [ascii::Char; 16] = *b"0123456789abcdef".as_ascii().unwrap();
 
@@ -82,7 +83,12 @@ impl<const N: usize> EscapeIterInner<N> {
         const { assert!(M <= N) };
 
         let mut data = [ascii::Char::Null; N];
-        data[..M].copy_from_slice(&array);
+
+        // SAFETY: `M` is smaller than or equal to `N`, and `data` does not overlap `array`.
+        unsafe {
+            ptr::copy_nonoverlapping(array.as_ptr(), data.as_mut_ptr(), M);
+        }
+
         Self::new(data, 0..M as u8)
     }