From caf585c978f43ef0348dcd669af301e7a7e8578b Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sun, 8 Dec 2024 10:34:17 -0800
Subject: [PATCH 1/2] Add test of deprecated type in From impl

    error: use of deprecated struct `test_deprecated::DeprecatedStruct`
      --> tests/test_lints.rs:73:13
       |
    73 |             DeprecatedStruct,
       |             ^^^^^^^^^^^^^^^^
       |
    note: the lint level is defined here
      --> tests/test_lints.rs:39:13
       |
    39 |     #![deny(deprecated)]
       |             ^^^^^^^^^^
---
 tests/test_lints.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tests/test_lints.rs b/tests/test_lints.rs
index b46a391..d272454 100644
--- a/tests/test_lints.rs
+++ b/tests/test_lints.rs
@@ -64,6 +64,16 @@ fn test_deprecated() {
         Variant,
     }
 
+    #[derive(Error, Debug)]
+    pub enum DeprecatedFrom {
+        #[error(transparent)]
+        Variant(
+            #[from]
+            #[allow(deprecated)]
+            DeprecatedStruct,
+        ),
+    }
+
     #[allow(deprecated)]
     let _: DeprecatedStruct;
     #[allow(deprecated)]

From 6e8c7244c9b396f0c194a660fcb4bcff75e50b08 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sun, 8 Dec 2024 10:37:43 -0800
Subject: [PATCH 2/2] Suppress deprecation warning on generated From impls

---
 impl/src/expand.rs | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/impl/src/expand.rs b/impl/src/expand.rs
index d0b302b..20ba1d2 100644
--- a/impl/src/expand.rs
+++ b/impl/src/expand.rs
@@ -170,10 +170,9 @@ fn impl_struct(input: Struct) -> TokenStream {
         let source_var = Ident::new("source", span);
         let body = from_initializer(from_field, backtrace_field, &source_var);
         quote_spanned! {span=>
-            #[allow(unused_qualifications, clippy::needless_lifetimes)]
+            #[allow(deprecated, unused_qualifications, clippy::needless_lifetimes)]
             #[automatically_derived]
             impl #impl_generics ::core::convert::From<#from> for #ty #ty_generics #where_clause {
-                #[allow(deprecated)]
                 fn from(#source_var: #from) -> Self {
                     #ty #body
                 }
@@ -435,10 +434,9 @@ fn impl_enum(input: Enum) -> TokenStream {
         let source_var = Ident::new("source", span);
         let body = from_initializer(from_field, backtrace_field, &source_var);
         Some(quote_spanned! {span=>
-            #[allow(unused_qualifications, clippy::needless_lifetimes)]
+            #[allow(deprecated, unused_qualifications, clippy::needless_lifetimes)]
             #[automatically_derived]
             impl #impl_generics ::core::convert::From<#from> for #ty #ty_generics #where_clause {
-                #[allow(deprecated)]
                 fn from(#source_var: #from) -> Self {
                     #ty::#variant #body
                 }