From 4c4bd3406705066223e9dddb909de7eddbeac861 Mon Sep 17 00:00:00 2001
From: Antoine PLASKOWSKI <antoine.plaskowski@epitech.eu>
Date: Fri, 12 Jul 2019 09:30:58 +0200
Subject: [PATCH] Fix miri error in into_inner() of CString

---
 src/libstd/ffi/c_str.rs | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 5c6c43017cf64..585731fb30e57 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -599,11 +599,12 @@ impl CString {
     ///
     /// [`Drop`]: ../ops/trait.Drop.html
     fn into_inner(self) -> Box<[u8]> {
-        unsafe {
-            let result = ptr::read(&self.inner);
-            mem::forget(self);
-            result
-        }
+        // Rationale: `mem::forget(self)` invalidates the previous call to `ptr::read(&self.inner)`
+        // so we use `ManuallyDrop` to ensure `self` is not dropped.
+        // Then we can return the box directly without invalidating it.
+        // See https://github.com/rust-lang/rust/issues/62553.
+        let this = mem::ManuallyDrop::new(self);
+        unsafe { ptr::read(&this.inner) }
     }
 }