11 files changed, 113 insertions, 144 deletions

diff --git a/vendor/serde_derive/.cargo-checksum.json b/vendor/serde_derive/.cargo-checksum.json
index 888714371..44476cfe8 100644
--- a/vendor/serde_derive/.cargo-checksum.json
+++ b/vendor/serde_derive/.cargo-checksum.json
@@ -1 +1 @@
-{"files":{"Cargo.toml":"d4c79a251c1bd0ed40ec6f4d8d06940542e54876e2327233a3e4737ab31d0860","LICENSE-APACHE":"62c7a1e35f56406896d7aa7ca52d0cc0d272ac022b5d2796e7d6905db8a3636a","LICENSE-MIT":"23f18e03dc49df91622fe2a76176497404e46ced8a715d9d2b67a7446571cca3","README.md":"13c66875efb67f64fdec817725f34ceb07913e1ebea4adc240868d2ed581d3da","build.rs":"d9a0df0c4dd552ff7fd0c3b3828cb1fff4fc4ab15bd98539881929b76b98003b","crates-io.md":"ee22254ee64c3189eef3e707c8d75dc66a8df2a7ee9e518d95238950780ec387","src/bound.rs":"9211d852730380be8e0af9ed5daa52e61563e598eef458739025551ba76aa7c6","src/de.rs":"4dde42292a4476f71b3790156fb2fbfbdba88ebad28c129065890d0f1470ff5d","src/dummy.rs":"31e02c3313d12c88b3b26baa49a9cb143440804b557b5255aad9a9b80b8ea1c6","src/fragment.rs":"5548ba65a53d90a296f60c1328a7a7fb040db467f59c2f5210b2fb320457145d","src/internals/ast.rs":"b019865eef92c1ddbb9029423ac22179f132dc655a51c09fb2a42f4aaef172fd","src/internals/attr.rs":"7407c6e85afd197bdbf715bd681bd171db37b2264f617e148ca340817f56e684","src/internals/case.rs":"9492f0c5142d7b7e8cd39c86d13a855e5ce4489425adb2b96aed89e1b7851ac0","src/internals/check.rs":"0449cc7653fc9e596f65028835bbb7d1545c10002c79c7608547f45a722c0040","src/internals/ctxt.rs":"6fa544ae52914498a62a395818ebdc1b36ac2fb5903c60afb741a864ad559f1c","src/internals/mod.rs":"f32138ff19d57eb00f88ba11f6b015efab2102657804f71ebbf386a3698dad91","src/internals/receiver.rs":"6b016351b8294539039095863d8c99e81dd4530d7f769003d12d4ca73cca172c","src/internals/respan.rs":"899753859c58ce5f532a3ec4584796a52f13ed5a0533191e48c953ba5c1b52ff","src/internals/symbol.rs":"2bf0287da64d28da7e8673af60f66aaf6b29efe33131e56b24d6fa55edb533ad","src/lib.rs":"0ed50d02eb095af7a0a57f571734f2c1ac0a704b498b88be3710f14335bd0f92","src/pretend.rs":"4aa53bf6c1350fbcfc8c4997f720cde61a8eb3aab73bb8c101b0f0a74901892b","src/ser.rs":"803f522d313e52eece8a91babfad9d35734d0bf04b042cf24d781294674ba8b3","src/this.rs":"a2c128955324c2994ed7cdc3fe4eeceb7ad8a0f9d071665a8378c85c8df64ce2","src/try.rs":"b171b0088c23ebf4bfa07ba457881b41ac5e547d55dd16f737ea988d34badf61"},"package":"291a097c63d8497e00160b166a967a4a79c64f3facdd01cbd7502231688d77df"}
\ No newline at end of file
+{"files":{"Cargo.toml":"57006278b8f645cedd47b3c0c7af2343388f43a6473c2f039e783c02ca030fc8","LICENSE-APACHE":"62c7a1e35f56406896d7aa7ca52d0cc0d272ac022b5d2796e7d6905db8a3636a","LICENSE-MIT":"23f18e03dc49df91622fe2a76176497404e46ced8a715d9d2b67a7446571cca3","README.md":"13c66875efb67f64fdec817725f34ceb07913e1ebea4adc240868d2ed581d3da","crates-io.md":"ee22254ee64c3189eef3e707c8d75dc66a8df2a7ee9e518d95238950780ec387","src/bound.rs":"9211d852730380be8e0af9ed5daa52e61563e598eef458739025551ba76aa7c6","src/de.rs":"240926ab4ea76bfe883e93d2b6ff252cfdbc46ae98fff1a64664e22bcac78daa","src/dummy.rs":"1b7de5bfe1158ea7e70d668d4f76fdccf7f63144ac7869e82e8bf1e7ea0db13c","src/fragment.rs":"5548ba65a53d90a296f60c1328a7a7fb040db467f59c2f5210b2fb320457145d","src/internals/ast.rs":"07dfd9a789cd6268c2cff2889e738193d24e68c93873792a0548d5e6b3c94ca4","src/internals/attr.rs":"b9f7a99895f4e9dbec433e14f647eb9ac1457ed7eb47180aaac3b4e8c6420be3","src/internals/case.rs":"9492f0c5142d7b7e8cd39c86d13a855e5ce4489425adb2b96aed89e1b7851ac0","src/internals/check.rs":"0449cc7653fc9e596f65028835bbb7d1545c10002c79c7608547f45a722c0040","src/internals/ctxt.rs":"c403db8260a533e58af06e8d0a2bb962edb13a250424ab1f1fd2719902affc37","src/internals/mod.rs":"f32138ff19d57eb00f88ba11f6b015efab2102657804f71ebbf386a3698dad91","src/internals/receiver.rs":"6b016351b8294539039095863d8c99e81dd4530d7f769003d12d4ca73cca172c","src/internals/respan.rs":"899753859c58ce5f532a3ec4584796a52f13ed5a0533191e48c953ba5c1b52ff","src/internals/symbol.rs":"2bf0287da64d28da7e8673af60f66aaf6b29efe33131e56b24d6fa55edb533ad","src/lib.rs":"fa8c851c7b681e0662bde69f7b03a3dfc3b32dc94e1687cadd57d95cfbba4d4e","src/pretend.rs":"0e570faf787015535ea6b6683ebc271633c1ca945d3ee1d072c497a1a920c380","src/ser.rs":"e435dc7ef8ee9dca02913f43b4162d22c664061510089745b6278a63df7d30fe","src/this.rs":"a2c128955324c2994ed7cdc3fe4eeceb7ad8a0f9d071665a8378c85c8df64ce2","src/try.rs":"b171b0088c23ebf4bfa07ba457881b41ac5e547d55dd16f737ea988d34badf61"},"package":"d9735b638ccc51c28bf6914d90a2e9725b377144fc612c49a611fddd1b631d68"}
\ No newline at end of file
diff --git a/vendor/serde_derive/Cargo.toml b/vendor/serde_derive/Cargo.toml
index a607f0428..e2865f5c6 100644
--- a/vendor/serde_derive/Cargo.toml
+++ b/vendor/serde_derive/Cargo.toml
@@ -12,7 +12,7 @@
 [package]
 rust-version = "1.56"
 name = "serde_derive"
-version = "1.0.160"
+version = "1.0.164"
 authors = [
     "Erick Tryzelaar <erick.tryzelaar@gmail.com>",
     "David Tolnay <dtolnay@gmail.com>",
diff --git a/vendor/serde_derive/build.rs b/vendor/serde_derive/build.rs
deleted file mode 100644
index 1249dab59..000000000
--- a/vendor/serde_derive/build.rs
+++ /dev/null
@@ -1,38 +0,0 @@
-use std::env;
-use std::process::Command;
-use std::str;
-
-// The rustc-cfg strings below are *not* public API. Please let us know by
-// opening a GitHub issue if your build environment requires some way to enable
-// these cfgs other than by executing our build script.
-fn main() {
-    println!("cargo:rerun-if-changed=build.rs");
-
-    let minor = match rustc_minor_version() {
-        Some(minor) => minor,
-        None => return,
-    };
-
-    // Underscore const names stabilized in Rust 1.37:
-    // https://blog.rust-lang.org/2019/08/15/Rust-1.37.0.html#using-unnamed-const-items-for-macros
-    if minor < 37 {
-        println!("cargo:rustc-cfg=no_underscore_consts");
-    }
-
-    // The ptr::addr_of! macro stabilized in Rust 1.51:
-    // https://blog.rust-lang.org/2021/03/25/Rust-1.51.0.html#stabilized-apis
-    if minor < 51 {
-        println!("cargo:rustc-cfg=no_ptr_addr_of");
-    }
-}
-
-fn rustc_minor_version() -> Option<u32> {
-    let rustc = env::var_os("RUSTC")?;
-    let output = Command::new(rustc).arg("--version").output().ok()?;
-    let version = str::from_utf8(&output.stdout).ok()?;
-    let mut pieces = version.split('.');
-    if pieces.next() != Some("rustc 1") {
-        return None;
-    }
-    pieces.next()?.parse().ok()
-}
diff --git a/vendor/serde_derive/src/de.rs b/vendor/serde_derive/src/de.rs
index 4d60d5a6f..a834a736e 100644
--- a/vendor/serde_derive/src/de.rs
+++ b/vendor/serde_derive/src/de.rs
@@ -15,9 +15,7 @@ use this;
 use std::collections::BTreeSet;
 use std::ptr;
 
-pub fn expand_derive_deserialize(
-    input: &mut syn::DeriveInput,
-) -> Result<TokenStream, Vec<syn::Error>> {
+pub fn expand_derive_deserialize(input: &mut syn::DeriveInput) -> syn::Result<TokenStream> {
     replace_receiver(input);
 
     let ctxt = Ctxt::new();
@@ -69,8 +67,6 @@ pub fn expand_derive_deserialize(
 
     Ok(dummy::wrap_in_const(
         cont.attrs.custom_serde_path(),
-        "DESERIALIZE",
-        ident,
         impl_block,
     ))
 }
@@ -1171,6 +1167,22 @@ fn deserialize_enum(
     variants: &[Variant],
     cattrs: &attr::Container,
 ) -> Fragment {
+    // The variants have already been checked (in ast.rs) that all untagged variants appear at the end
+    match variants.iter().position(|var| var.attrs.untagged()) {
+        Some(variant_idx) => {
+            let (tagged, untagged) = variants.split_at(variant_idx);
+            let tagged_frag = Expr(deserialize_homogeneous_enum(params, tagged, cattrs));
+            deserialize_untagged_enum_after(params, untagged, cattrs, Some(tagged_frag))
+        }
+        None => deserialize_homogeneous_enum(params, variants, cattrs),
+    }
+}
+
+fn deserialize_homogeneous_enum(
+    params: &Parameters,
+    variants: &[Variant],
+    cattrs: &attr::Container,
+) -> Fragment {
     match cattrs.tag() {
         attr::TagType::External => deserialize_externally_tagged_enum(params, variants, cattrs),
         attr::TagType::Internal { tag } => {
@@ -1671,6 +1683,16 @@ fn deserialize_untagged_enum(
     variants: &[Variant],
     cattrs: &attr::Container,
 ) -> Fragment {
+    let first_attempt = None;
+    deserialize_untagged_enum_after(params, variants, cattrs, first_attempt)
+}
+
+fn deserialize_untagged_enum_after(
+    params: &Parameters,
+    variants: &[Variant],
+    cattrs: &attr::Container,
+    first_attempt: Option<Expr>,
+) -> Fragment {
     let attempts = variants
         .iter()
         .filter(|variant| !variant.attrs.skip_deserializing())
@@ -1679,12 +1701,10 @@ fn deserialize_untagged_enum(
                 params,
                 variant,
                 cattrs,
-                quote!(
-                    _serde::__private::de::ContentRefDeserializer::<__D::Error>::new(&__content)
-                ),
+                quote!(__deserializer),
             ))
         });
-
+    let attempts = first_attempt.into_iter().chain(attempts);
     // TODO this message could be better by saving the errors from the failed
     // attempts. The heuristic used by TOML was to count the number of fields
     // processed before an error, and use the error that happened after the
@@ -1699,6 +1719,7 @@ fn deserialize_untagged_enum(
 
     quote_block! {
         let __content = try!(<_serde::__private::de::Content as _serde::Deserialize>::deserialize(__deserializer));
+        let __deserializer = _serde::__private::de::ContentRefDeserializer::<__D::Error>::new(&__content);
 
         #(
             if let _serde::__private::Ok(__ok) = #attempts {
@@ -3086,23 +3107,31 @@ struct DeTypeGenerics<'a>(&'a Parameters);
 #[cfg(feature = "deserialize_in_place")]
 struct InPlaceTypeGenerics<'a>(&'a Parameters);
 
+fn de_type_generics_to_tokens(
+    mut generics: syn::Generics,
+    borrowed: &BorrowedLifetimes,
+    tokens: &mut TokenStream,
+) {
+    if borrowed.de_lifetime_param().is_some() {
+        let def = syn::LifetimeParam {
+            attrs: Vec::new(),
+            lifetime: syn::Lifetime::new("'de", Span::call_site()),
+            colon_token: None,
+            bounds: Punctuated::new(),
+        };
+        // Prepend 'de lifetime to list of generics
+        generics.params = Some(syn::GenericParam::Lifetime(def))
+            .into_iter()
+            .chain(generics.params)
+            .collect();
+    }
+    let (_, ty_generics, _) = generics.split_for_impl();
+    ty_generics.to_tokens(tokens);
+}
+
 impl<'a> ToTokens for DeTypeGenerics<'a> {
     fn to_tokens(&self, tokens: &mut TokenStream) {
-        let mut generics = self.0.generics.clone();
-        if self.0.borrowed.de_lifetime_param().is_some() {
-            let def = syn::LifetimeParam {
-                attrs: Vec::new(),
-                lifetime: syn::Lifetime::new("'de", Span::call_site()),
-                colon_token: None,
-                bounds: Punctuated::new(),
-            };
-            generics.params = Some(syn::GenericParam::Lifetime(def))
-                .into_iter()
-                .chain(generics.params)
-                .collect();
-        }
-        let (_, ty_generics, _) = generics.split_for_impl();
-        ty_generics.to_tokens(tokens);
+        de_type_generics_to_tokens(self.0.generics.clone(), &self.0.borrowed, tokens);
     }
 }
 
@@ -3115,20 +3144,7 @@ impl<'a> ToTokens for InPlaceTypeGenerics<'a> {
             .chain(generics.params)
             .collect();
 
-        if self.0.borrowed.de_lifetime_param().is_some() {
-            let def = syn::LifetimeParam {
-                attrs: Vec::new(),
-                lifetime: syn::Lifetime::new("'de", Span::call_site()),
-                colon_token: None,
-                bounds: Punctuated::new(),
-            };
-            generics.params = Some(syn::GenericParam::Lifetime(def))
-                .into_iter()
-                .chain(generics.params)
-                .collect();
-        }
-        let (_, ty_generics, _) = generics.split_for_impl();
-        ty_generics.to_tokens(tokens);
+        de_type_generics_to_tokens(generics, &self.0.borrowed, tokens);
     }
 }
 
diff --git a/vendor/serde_derive/src/dummy.rs b/vendor/serde_derive/src/dummy.rs
index 2be502713..57e8eabf2 100644
--- a/vendor/serde_derive/src/dummy.rs
+++ b/vendor/serde_derive/src/dummy.rs
@@ -1,23 +1,11 @@
-use proc_macro2::{Ident, TokenStream};
-use quote::format_ident;
+use proc_macro2::TokenStream;
 
 use syn;
 use try;
 
-pub fn wrap_in_const(
-    serde_path: Option<&syn::Path>,
-    trait_: &str,
-    ty: &Ident,
-    code: TokenStream,
-) -> TokenStream {
+pub fn wrap_in_const(serde_path: Option<&syn::Path>, code: TokenStream) -> TokenStream {
     let try_replacement = try::replacement();
 
-    let dummy_const = if cfg!(no_underscore_consts) {
-        format_ident!("_IMPL_{}_FOR_{}", trait_, unraw(ty))
-    } else {
-        format_ident!("_")
-    };
-
     let use_serde = match serde_path {
         Some(path) => quote! {
             use #path as _serde;
@@ -31,14 +19,10 @@ pub fn wrap_in_const(
     quote! {
         #[doc(hidden)]
         #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-        const #dummy_const: () = {
+        const _: () = {
             #use_serde
             #try_replacement
             #code
         };
     }
 }
-
-fn unraw(ident: &Ident) -> String {
-    ident.to_string().trim_start_matches("r#").to_owned()
-}
diff --git a/vendor/serde_derive/src/internals/ast.rs b/vendor/serde_derive/src/internals/ast.rs
index 2a6950b2a..8bcb0ecd1 100644
--- a/vendor/serde_derive/src/internals/ast.rs
+++ b/vendor/serde_derive/src/internals/ast.rs
@@ -140,7 +140,7 @@ fn enum_from_ast<'a>(
     variants: &'a Punctuated<syn::Variant, Token![,]>,
     container_default: &attr::Default,
 ) -> Vec<Variant<'a>> {
-    variants
+    let variants: Vec<Variant> = variants
         .iter()
         .map(|variant| {
             let attrs = attr::Variant::from_ast(cx, variant);
@@ -154,7 +154,20 @@ fn enum_from_ast<'a>(
                 original: variant,
             }
         })
-        .collect()
+        .collect();
+
+    let index_of_last_tagged_variant = variants
+        .iter()
+        .rposition(|variant| !variant.attrs.untagged());
+    if let Some(index_of_last_tagged_variant) = index_of_last_tagged_variant {
+        for variant in &variants[..index_of_last_tagged_variant] {
+            if variant.attrs.untagged() {
+                cx.error_spanned_by(&variant.ident, "all variants with the #[serde(untagged)] attribute must be placed at the end of the enum");
+            }
+        }
+    }
+
+    variants
 }
 
 fn struct_from_ast<'a>(
diff --git a/vendor/serde_derive/src/internals/attr.rs b/vendor/serde_derive/src/internals/attr.rs
index b0a7d08a2..bff82191b 100644
--- a/vendor/serde_derive/src/internals/attr.rs
+++ b/vendor/serde_derive/src/internals/attr.rs
@@ -740,6 +740,7 @@ pub struct Variant {
     serialize_with: Option<syn::ExprPath>,
     deserialize_with: Option<syn::ExprPath>,
     borrow: Option<BorrowAttribute>,
+    untagged: bool,
 }
 
 struct BorrowAttribute {
@@ -762,6 +763,7 @@ impl Variant {
         let mut serialize_with = Attr::none(cx, SERIALIZE_WITH);
         let mut deserialize_with = Attr::none(cx, DESERIALIZE_WITH);
         let mut borrow = Attr::none(cx, BORROW);
+        let mut untagged = BoolAttr::none(cx, UNTAGGED);
 
         for attr in &variant.attrs {
             if attr.path() != SERDE {
@@ -879,6 +881,8 @@ impl Variant {
                             cx.error_spanned_by(variant, msg);
                         }
                     }
+                } else if meta.path == UNTAGGED {
+                    untagged.set_true(&meta.path);
                 } else {
                     let path = meta.path.to_token_stream().to_string().replace(' ', "");
                     return Err(
@@ -905,6 +909,7 @@ impl Variant {
             serialize_with: serialize_with.get(),
             deserialize_with: deserialize_with.get(),
             borrow: borrow.get(),
+            untagged: untagged.get(),
         }
     }
 
@@ -956,6 +961,10 @@ impl Variant {
     pub fn deserialize_with(&self) -> Option<&syn::ExprPath> {
         self.deserialize_with.as_ref()
     }
+
+    pub fn untagged(&self) -> bool {
+        self.untagged
+    }
 }
 
 /// Represents field attribute information
diff --git a/vendor/serde_derive/src/internals/ctxt.rs b/vendor/serde_derive/src/internals/ctxt.rs
index d692c2a44..707bed90e 100644
--- a/vendor/serde_derive/src/internals/ctxt.rs
+++ b/vendor/serde_derive/src/internals/ctxt.rs
@@ -44,12 +44,19 @@ impl Ctxt {
     }
 
     /// Consume this object, producing a formatted error string if there are errors.
-    pub fn check(self) -> Result<(), Vec<syn::Error>> {
-        let errors = self.errors.borrow_mut().take().unwrap();
-        match errors.len() {
-            0 => Ok(()),
-            _ => Err(errors),
+    pub fn check(self) -> syn::Result<()> {
+        let mut errors = self.errors.borrow_mut().take().unwrap().into_iter();
+
+        let mut combined = match errors.next() {
+            Some(first) => first,
+            None => return Ok(()),
+        };
+
+        for rest in errors {
+            combined.combine(rest);
         }
+
+        Err(combined)
     }
 }
 
diff --git a/vendor/serde_derive/src/lib.rs b/vendor/serde_derive/src/lib.rs
index 947033b78..e632cc9f5 100644
--- a/vendor/serde_derive/src/lib.rs
+++ b/vendor/serde_derive/src/lib.rs
@@ -13,7 +13,7 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.160")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.164")]
 #![allow(unknown_lints, bare_trait_objects)]
 // Ignored clippy lints
 #![allow(
@@ -92,7 +92,7 @@ mod try;
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
     let mut input = parse_macro_input!(input as DeriveInput);
     ser::expand_derive_serialize(&mut input)
-        .unwrap_or_else(to_compile_errors)
+        .unwrap_or_else(syn::Error::into_compile_error)
         .into()
 }
 
@@ -100,11 +100,6 @@ pub fn derive_serialize(input: TokenStream) -> TokenStream {
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
     let mut input = parse_macro_input!(input as DeriveInput);
     de::expand_derive_deserialize(&mut input)
-        .unwrap_or_else(to_compile_errors)
+        .unwrap_or_else(syn::Error::into_compile_error)
         .into()
 }
-
-fn to_compile_errors(errors: Vec<syn::Error>) -> proc_macro2::TokenStream {
-    let compile_errors = errors.iter().map(syn::Error::to_compile_error);
-    quote!(#(#compile_errors)*)
-}
diff --git a/vendor/serde_derive/src/pretend.rs b/vendor/serde_derive/src/pretend.rs
index d7b953d63..7decbaa52 100644
--- a/vendor/serde_derive/src/pretend.rs
+++ b/vendor/serde_derive/src/pretend.rs
@@ -97,29 +97,14 @@ fn pretend_fields_used_struct_packed(cont: &Container, fields: &[Field]) -> Toke
 
     let members = fields.iter().map(|field| &field.member).collect::<Vec<_>>();
 
-    #[cfg(not(no_ptr_addr_of))]
-    {
-        quote! {
-            match _serde::__private::None::<&#type_ident #ty_generics> {
-                _serde::__private::Some(__v @ #type_ident { #(#members: _),* }) => {
-                    #(
-                        let _ = _serde::__private::ptr::addr_of!(__v.#members);
-                    )*
-                }
-                _ => {}
-            }
-        }
-    }
-
-    #[cfg(no_ptr_addr_of)]
-    {
-        let placeholders = (0usize..).map(|i| format_ident!("__v{}", i));
-
-        quote! {
-            match _serde::__private::None::<#type_ident #ty_generics> {
-                _serde::__private::Some(#type_ident { #(#members: #placeholders),* }) => {}
-                _ => {}
+    quote! {
+        match _serde::__private::None::<&#type_ident #ty_generics> {
+            _serde::__private::Some(__v @ #type_ident { #(#members: _),* }) => {
+                #(
+                    let _ = _serde::__private::ptr::addr_of!(__v.#members);
+                )*
             }
+            _ => {}
         }
     }
 }
diff --git a/vendor/serde_derive/src/ser.rs b/vendor/serde_derive/src/ser.rs
index f223f713a..b9a9dce21 100644
--- a/vendor/serde_derive/src/ser.rs
+++ b/vendor/serde_derive/src/ser.rs
@@ -10,9 +10,7 @@ use internals::{attr, replace_receiver, Ctxt, Derive};
 use pretend;
 use this;
 
-pub fn expand_derive_serialize(
-    input: &mut syn::DeriveInput,
-) -> Result<TokenStream, Vec<syn::Error>> {
+pub fn expand_derive_serialize(input: &mut syn::DeriveInput) -> syn::Result<TokenStream> {
     replace_receiver(input);
 
     let ctxt = Ctxt::new();
@@ -59,8 +57,6 @@ pub fn expand_derive_serialize(
 
     Ok(dummy::wrap_in_const(
         cont.attrs.custom_serde_path(),
-        "SERIALIZE",
-        ident,
         impl_block,
     ))
 }
@@ -477,17 +473,19 @@ fn serialize_variant(
             }
         };
 
-        let body = Match(match cattrs.tag() {
-            attr::TagType::External => {
+        let body = Match(match (cattrs.tag(), variant.attrs.untagged()) {
+            (attr::TagType::External, false) => {
                 serialize_externally_tagged_variant(params, variant, variant_index, cattrs)
             }
-            attr::TagType::Internal { tag } => {
+            (attr::TagType::Internal { tag }, false) => {
                 serialize_internally_tagged_variant(params, variant, cattrs, tag)
             }
-            attr::TagType::Adjacent { tag, content } => {
+            (attr::TagType::Adjacent { tag, content }, false) => {
                 serialize_adjacently_tagged_variant(params, variant, cattrs, tag, content)
             }
-            attr::TagType::None => serialize_untagged_variant(params, variant, cattrs),
+            (attr::TagType::None, _) | (_, true) => {
+                serialize_untagged_variant(params, variant, cattrs)
+            }
         });
 
         quote! {