From 6d61c1578f067c1d6b121142cb00b729b92f964f Mon Sep 17 00:00:00 2001
From: Amanieu d'Antras <amanieu@gmail.com>
Date: Thu, 2 Dec 2021 11:51:02 +0000
Subject: [PATCH] Add a proper implementation of Clone for C API vector types

The previous implementation used a shallow copy, which is incorrect and
could lead to a use-after-free.
---
 crates/c-api/src/vec.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/crates/c-api/src/vec.rs b/crates/c-api/src/vec.rs
index 1b45aeff22..9091fa7e20 100644
--- a/crates/c-api/src/vec.rs
+++ b/crates/c-api/src/vec.rs
@@ -29,7 +29,6 @@ macro_rules! declare_vecs {
         ))*
     ) => {$(
         #[repr(C)]
-        #[derive(Clone)]
         pub struct $name {
             size: usize,
             data: *mut $elem_ty,
@@ -80,6 +79,12 @@ macro_rules! declare_vecs {
             }
         }
 
+        impl Clone for $name {
+            fn clone(&self) -> Self {
+                self.as_slice().to_vec().into()
+            }
+        }
+
         impl From<Vec<$elem_ty>> for $name {
             fn from(vec: Vec<$elem_ty>) -> Self {
                 let mut vec = vec.into_boxed_slice();