From e2000abcf23ed8a88e0f5c011c4864259e1fa1f8 Mon Sep 17 00:00:00 2001
From: Pointerbender <pointerbender@gmail.com>
Date: Tue, 25 May 2021 16:26:22 +0200
Subject: [PATCH] fixed UB in <[T]>::copy_within method

---
 library/core/src/slice/mod.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs
index 0923175414edd..28fa07829d1a4 100644
--- a/library/core/src/slice/mod.rs
+++ b/library/core/src/slice/mod.rs
@@ -3093,10 +3093,11 @@ impl<T> [T] {
         let Range { start: src_start, end: src_end } = slice::range(src, ..self.len());
         let count = src_end - src_start;
         assert!(dest <= self.len() - count, "dest is out of bounds");
+        let ptr = self.as_mut_ptr();
         // SAFETY: the conditions for `ptr::copy` have all been checked above,
         // as have those for `ptr::add`.
         unsafe {
-            ptr::copy(self.as_ptr().add(src_start), self.as_mut_ptr().add(dest), count);
+            ptr::copy(ptr.add(src_start), ptr.add(dest), count);
         }
     }