Release 1.0.190

Ensure f32 deserialized from f64 and vice versa preserve NaN sign

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.189" # remember to update html_root_url and serde_derive dependency
+version = "1.0.190"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 build = "build.rs"
 categories = ["encoding", "no-std", "no-std::no-alloc"]
@@ -37,7 +37,7 @@ rustdoc-args = ["--generate-link-to-definition"]
 # is compatible with exactly one serde release because the generated code
 # involves nonpublic APIs which are not bound by semver.
 [target.'cfg(any())'.dependencies]
-serde_derive = { version = "=1.0.189", path = "../serde_derive" }
+serde_derive = { version = "=1.0.190", path = "../serde_derive" }
 
 
 ### FEATURES #################################################################

serde/build.rs

@@ -27,6 +27,12 @@ fn main() {
         println!("cargo:rustc-cfg=no_relaxed_trait_bounds");
     }
 
+    // f32::copysign and f64::copysign stabilized in Rust 1.35.
+    // https://blog.rust-lang.org/2019/05/23/Rust-1.35.0.html#copy-the-sign-of-a-floating-point-number-onto-another
+    if minor < 35 {
+        println!("cargo:rustc-cfg=no_float_copysign");
+    }
+
     // Current minimum supported version of serde_derive crate is Rust 1.56.
     if minor < 56 {
         println!("cargo:rustc-cfg=no_serde_derive");

serde/src/de/impls.rs

@@ -180,6 +180,28 @@ macro_rules! num_as_self {
     };
 }
 
+macro_rules! num_as_copysign_self {
+    ($ty:ident : $visit:ident) => {
+        #[inline]
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            #[cfg(any(no_float_copysign, not(feature = "std")))]
+            {
+                Ok(v as Self::Value)
+            }
+
+            #[cfg(all(not(no_float_copysign), feature = "std"))]
+            {
+                // Preserve sign of NaN. The `as` produces a nondeterministic sign.
+                let sign = if v.is_sign_positive() { 1.0 } else { -1.0 };
+                Ok((v as Self::Value).copysign(sign))
+            }
+        }
+    };
+}
+
 macro_rules! int_to_int {
     ($ty:ident : $visit:ident) => {
         #[inline]
@@ -351,7 +373,7 @@ impl_deserialize_num! {
 impl_deserialize_num! {
     f32, deserialize_f32
     num_self!(f32:visit_f32);
-    num_as_self!(f64:visit_f64);
+    num_as_copysign_self!(f64:visit_f64);
     num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
     num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
 }
@@ -359,7 +381,7 @@ impl_deserialize_num! {
 impl_deserialize_num! {
     f64, deserialize_f64
     num_self!(f64:visit_f64);
-    num_as_self!(f32:visit_f32);
+    num_as_copysign_self!(f32:visit_f32);
     num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
     num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
 }

serde/src/lib.rs

@@ -95,7 +95,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.189")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.190")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Unstable functionality only if the user asks for it. For tracking and
@@ -168,11 +168,14 @@ mod lib {
         pub use std::*;
     }
 
-    pub use self::core::{cmp, iter, mem, num, ptr, slice, str};
     pub use self::core::{f32, f64};
     pub use self::core::{i16, i32, i64, i8, isize};
+    pub use self::core::{iter, num, ptr, str};
     pub use self::core::{u16, u32, u64, u8, usize};
 
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    pub use self::core::{cmp, mem, slice};
+
     pub use self::core::cell::{Cell, RefCell};
     pub use self::core::clone::{self, Clone};
     pub use self::core::cmp::Reverse;

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.189" # remember to update html_root_url
+version = "1.0.190"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 categories = ["no-std", "no-std::no-alloc"]
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"

serde_derive/src/de.rs

@@ -1840,7 +1840,7 @@ fn deserialize_internally_tagged_variant(
             let this_value = &params.this_value;
             let type_name = params.type_name();
             let variant_name = variant.ident.to_string();
-            let default = variant.fields.get(0).map(|field| {
+            let default = variant.fields.first().map(|field| {
                 let default = Expr(expr_is_missing(field, cattrs));
                 quote!((#default))
             });
@@ -1885,7 +1885,7 @@ fn deserialize_untagged_variant(
             let this_value = &params.this_value;
             let type_name = params.type_name();
             let variant_name = variant.ident.to_string();
-            let default = variant.fields.get(0).map(|field| {
+            let default = variant.fields.first().map(|field| {
                 let default = Expr(expr_is_missing(field, cattrs));
                 quote!((#default))
             });

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/1.0.189")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.190")]
 // Ignored clippy lints
 #![allow(
     // clippy false positive: https://github.com/rust-lang/rust-clippy/issues/7054

serde_derive_internals/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive_internals"
-version = "0.29.0" # remember to update html_root_url
+version = "0.29.0"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 description = "AST representation used by Serde derive macros. Unstable."
 documentation = "https://docs.rs/serde_derive_internals"

test_suite/tests/test_de.rs

@@ -11,6 +11,7 @@
 #![cfg_attr(feature = "unstable", feature(never_type))]
 
 use fnv::FnvHasher;
+use serde::de::value::{F32Deserializer, F64Deserializer};
 use serde::de::{Deserialize, DeserializeOwned, Deserializer, IntoDeserializer};
 use serde_derive::Deserialize;
 use serde_test::{assert_de_tokens, Configure, Token};
@@ -832,6 +833,26 @@ fn test_f64() {
     test(1.11, &[Token::F64(1.11)]);
 }
 
+#[test]
+fn test_nan() {
+    let f32_deserializer = F32Deserializer::<serde::de::value::Error>::new;
+    let f64_deserializer = F64Deserializer::<serde::de::value::Error>::new;
+
+    let pos_f32_nan = f32_deserializer(f32::NAN.copysign(1.0));
+    let pos_f64_nan = f64_deserializer(f64::NAN.copysign(1.0));
+    assert!(f32::deserialize(pos_f32_nan).unwrap().is_sign_positive());
+    assert!(f32::deserialize(pos_f64_nan).unwrap().is_sign_positive());
+    assert!(f64::deserialize(pos_f32_nan).unwrap().is_sign_positive());
+    assert!(f64::deserialize(pos_f64_nan).unwrap().is_sign_positive());
+
+    let neg_f32_nan = f32_deserializer(f32::NAN.copysign(-1.0));
+    let neg_f64_nan = f64_deserializer(f64::NAN.copysign(-1.0));
+    assert!(f32::deserialize(neg_f32_nan).unwrap().is_sign_negative());
+    assert!(f32::deserialize(neg_f64_nan).unwrap().is_sign_negative());
+    assert!(f64::deserialize(neg_f32_nan).unwrap().is_sign_negative());
+    assert!(f64::deserialize(neg_f64_nan).unwrap().is_sign_negative());
+}
+
 #[test]
 fn test_char() {
     test('a', &[Token::Char('a')]);