Extract combined backtrace-source case to separate match arm

dtolnay · Aug 28, 2021 · 799bb53 · 799bb53
1 parent d49c5af
commit 799bb53
Showing 1 changed file with 26 additions and 24 deletions.
diff --git a/impl/src/expand.rs b/impl/src/expand.rs
@@ -240,36 +240,38 @@ fn impl_enum(input: Enum) -> TokenStream {
                         }
                     }
                 }
-                (Some(backtrace_field), _) => {
+                (Some(backtrace_field), Some(source_field))
+                    if backtrace_field.member == source_field.member =>
+                {
                     let backtrace = &backtrace_field.member;
-                    if variant.source_field().map_or(false, |f| f.member == *backtrace) {
-                        let varsource = quote!(source);
-                        let source_backtrace = if type_is_option(backtrace_field.ty) {
-                            quote_spanned! {backtrace.span()=>
-                                #varsource.as_ref().and_then(|source| source.as_dyn_error().backtrace())
-                            }
-                        } else {
-                            quote_spanned! {backtrace.span()=>
-                                #varsource.as_dyn_error().backtrace()
-                            }
-                        };
-                        quote! {
-                            #ty::#ident {#backtrace: #varsource, ..} => {
-                                use thiserror::private::AsDynError;
-                                #source_backtrace
-                            }
+                    let varsource = quote!(source);
+                    let source_backtrace = if type_is_option(source_field.ty) {
+                        quote_spanned! {backtrace.span()=>
+                            #varsource.as_ref().and_then(|source| source.as_dyn_error().backtrace())
                         }
                     } else {
-                        let body = if type_is_option(backtrace_field.ty) {
-                            quote!(backtrace.as_ref())
-                        } else {
-                            quote!(std::option::Option::Some(backtrace))
-                        };
-                        quote! {
-                            #ty::#ident {#backtrace: backtrace, ..} => #body,
+                        quote_spanned! {backtrace.span()=>
+                            #varsource.as_dyn_error().backtrace()
+                        }
+                    };
+                    quote! {
+                        #ty::#ident {#backtrace: #varsource, ..} => {
+                            use thiserror::private::AsDynError;
+                            #source_backtrace
                         }
                     }
                 }
+                (Some(backtrace_field), _) => {
+                    let backtrace = &backtrace_field.member;
+                    let body = if type_is_option(backtrace_field.ty) {
+                        quote!(backtrace.as_ref())
+                    } else {
+                        quote!(std::option::Option::Some(backtrace))
+                    };
+                    quote! {
+                        #ty::#ident {#backtrace: backtrace, ..} => #body,
+                    }
+                }
                 (None, _) => quote! {
                     #ty::#ident {..} => std::option::Option::None,
                 },