From 7e743be9d873178e9bf94c91f8017a0865431c23 Mon Sep 17 00:00:00 2001
From: missing <piecenotfound@gmail.com>
Date: Sun, 14 Aug 2022 18:31:10 -0500
Subject: [PATCH] found the soundness hole

---
 src/impls.rs | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/impls.rs b/src/impls.rs
index 4cbd5e6..776d3ec 100644
--- a/src/impls.rs
+++ b/src/impls.rs
@@ -6,6 +6,7 @@ use std::{
     fmt::Debug,
     mem::size_of,
     ops::{Deref, DerefMut},
+    ptr::NonNull,
     slice,
     vec::Vec as StdVec,
 };
@@ -161,13 +162,21 @@ impl<T> Deref for Vec<T> {
     type Target = [T];
 
     fn deref(&self) -> &Self::Target {
-        unsafe { slice::from_raw_parts(self.get_ptr(0), self.len) }
+        if self.is_empty() {
+            unsafe { slice::from_raw_parts(NonNull::dangling().as_ptr(), 0) }
+        } else {
+            unsafe { slice::from_raw_parts(self.get_ptr(0), self.len) }
+        }
     }
 }
 
 impl<T> DerefMut for Vec<T> {
     fn deref_mut(&mut self) -> &mut Self::Target {
-        unsafe { slice::from_raw_parts_mut(self.get_ptr(0) as _, self.len) }
+        if self.is_empty() {
+            unsafe { slice::from_raw_parts_mut(NonNull::dangling().as_ptr(), 0) }
+        } else {
+            unsafe { slice::from_raw_parts_mut(self.get_ptr(0) as _, self.len) }
+        }
     }
 }