From ea99e8b68635e2506dc5dfec5e9a0aba41d6652d Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sat, 21 Jan 2017 12:18:55 -0800
Subject: [PATCH] Filter the slice of expected field and variant names

---
 serde_codegen/src/de.rs           | 29 ++++++++++++++++-------------
 testing/tests/test_annotations.rs |  4 ++--
 2 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/serde_codegen/src/de.rs b/serde_codegen/src/de.rs
index 32f186ee..e9771247 100644
--- a/serde_codegen/src/de.rs
+++ b/serde_codegen/src/de.rs
@@ -489,24 +489,25 @@ fn deserialize_item_enum(
 
     let type_name = item_attrs.name().deserialize_name();
 
-    let variant_names_idents = variants.iter()
+    let variant_names_idents: Vec<_> = variants.iter()
         .enumerate()
         .filter(|&(_, variant)| !variant.attrs.skip_deserializing())
         .map(|(i, variant)| (variant.attrs.name().deserialize_name(), field_i(i)))
         .collect();
 
+    let variants_stmt = {
+        let variant_names = variant_names_idents.iter().map(|&(ref name, _)| name);
+        quote! {
+            const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ];
+        }
+    };
+
     let variant_visitor = deserialize_field_visitor(
         variant_names_idents,
         item_attrs,
         true,
     );
 
-    let variant_names = variants.iter().map(|variant| variant.attrs.name().deserialize_name());
-
-    let variants_stmt = quote! {
-        const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ];
-    };
-
     // Match arms to extract a variant from a string
     let variant_arms = variants.iter()
         .enumerate()
@@ -713,12 +714,19 @@ fn deserialize_struct_visitor(
     fields: &[Field],
     item_attrs: &attr::Item,
 ) -> (Tokens, Tokens, Tokens) {
-    let field_names_idents = fields.iter()
+    let field_names_idents: Vec<_> = fields.iter()
         .enumerate()
         .filter(|&(_, field)| !field.attrs.skip_deserializing())
         .map(|(i, field)| (field.attrs.name().deserialize_name(), field_i(i)))
         .collect();
 
+    let fields_stmt = {
+        let field_names = field_names_idents.iter().map(|&(ref name, _)| name);
+        quote! {
+            const FIELDS: &'static [&'static str] = &[ #(#field_names),* ];
+        }
+    };
+
     let field_visitor = deserialize_field_visitor(
         field_names_idents,
         item_attrs,
@@ -733,11 +741,6 @@ fn deserialize_struct_visitor(
         item_attrs,
     );
 
-    let field_names = fields.iter().map(|field| field.attrs.name().deserialize_name());
-    let fields_stmt = quote! {
-        const FIELDS: &'static [&'static str] = &[ #(#field_names),* ];
-    };
-
     (field_visitor, fields_stmt, visit_map)
 }
 
diff --git a/testing/tests/test_annotations.rs b/testing/tests/test_annotations.rs
index 0649a8e7..e1774122 100644
--- a/testing/tests/test_annotations.rs
+++ b/testing/tests/test_annotations.rs
@@ -145,7 +145,7 @@ fn test_default_enum() {
     assert_de_tokens(
         &DefaultEnum::Struct { a1: 1, a2: 2, a3: 3, a4: 0, a5: 123 },
         &[
-            Token::EnumMapStart("DefaultEnum", "Struct", 5),
+            Token::EnumMapStart("DefaultEnum", "Struct", 3),
 
             Token::EnumMapSep,
             Token::Str("a1"),
@@ -174,7 +174,7 @@ fn test_default_enum() {
     assert_de_tokens(
         &DefaultEnum::Struct { a1: 1, a2: 0, a3: 123, a4: 0, a5: 123 },
         &[
-            Token::EnumMapStart("DefaultEnum", "Struct", 5),
+            Token::EnumMapStart("DefaultEnum", "Struct", 3),
 
             Token::EnumMapSep,
             Token::Str("a1"),