From ba4e7e732dea2c9adaf6fa4803362cd9a2b1adfe Mon Sep 17 00:00:00 2001
From: daxpedda <daxpedda@gmail.com>
Date: Mon, 31 Jan 2022 16:04:57 +0100
Subject: [PATCH] Fix ambiguous method for `AssertZeroizeOnDrop` (#725)

---
 zeroize/src/lib.rs              |  2 +-
 zeroize/tests/zeroize_derive.rs | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/zeroize/src/lib.rs b/zeroize/src/lib.rs
index 7890d8f8..3f1fd1f9 100644
--- a/zeroize/src/lib.rs
+++ b/zeroize/src/lib.rs
@@ -271,7 +271,7 @@ pub mod __internal {
         fn zeroize_or_on_drop(self);
     }
 
-    impl<T: ZeroizeOnDrop> AssertZeroizeOnDrop for &mut T {
+    impl<T: ZeroizeOnDrop> AssertZeroizeOnDrop for &&mut T {
         fn zeroize_or_on_drop(self) {}
     }
 
diff --git a/zeroize/tests/zeroize_derive.rs b/zeroize/tests/zeroize_derive.rs
index 1e9e12ac..9775ab06 100644
--- a/zeroize/tests/zeroize_derive.rs
+++ b/zeroize/tests/zeroize_derive.rs
@@ -242,7 +242,7 @@ mod custom_derive_tests {
     }
 
     #[test]
-    fn derive_only_zeroize_on_drop() {
+    fn derive_inherit_zeroize_on_drop() {
         #[derive(ZeroizeOnDrop)]
         struct X([u8; 3]);
 
@@ -255,4 +255,34 @@ mod custom_derive_tests {
         }
         assert_eq!(&value.0 .0, &[0, 0, 0])
     }
+
+    #[test]
+    fn derive_inherit_from_both() {
+        #[derive(Zeroize, ZeroizeOnDrop)]
+        struct X([u8; 3]);
+
+        #[derive(ZeroizeOnDrop)]
+        struct Z(X);
+
+        let mut value = Z(X([1, 2, 3]));
+        unsafe {
+            std::ptr::drop_in_place(&mut value);
+        }
+        assert_eq!(&value.0 .0, &[0, 0, 0])
+    }
+
+    #[test]
+    fn derive_inherit_both() {
+        #[derive(Zeroize, ZeroizeOnDrop)]
+        struct X([u8; 3]);
+
+        #[derive(Zeroize, ZeroizeOnDrop)]
+        struct Z(X);
+
+        let mut value = Z(X([1, 2, 3]));
+        unsafe {
+            std::ptr::drop_in_place(&mut value);
+        }
+        assert_eq!(&value.0 .0, &[0, 0, 0])
+    }
 }