chore(actix-http): prepare release 3.5.1

fixes #3229

actix-http/CHANGES.md

@@ -2,6 +2,12 @@
 
 ## Unreleased
 
+## 3.5.1
+
+## Fixed
+
+- Prevent hang when returning zero-sized response bodies through compression layer.
+
 ## 3.5.0
 
 ### Changed

actix-http/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "actix-http"
-version = "3.5.0"
+version = "3.5.1"
 authors = [
     "Nikolay Kim <fafhrd91@gmail.com>",
     "Rob Ede <robjtede@icloud.com>",

actix-http/README.md

@@ -5,11 +5,11 @@
 <!-- prettier-ignore-start -->
 
 [![crates.io](https://img.shields.io/crates/v/actix-http?label=latest)](https://crates.io/crates/actix-http)
-[![Documentation](https://docs.rs/actix-http/badge.svg?version=3.5.0)](https://docs.rs/actix-http/3.5.0)
+[![Documentation](https://docs.rs/actix-http/badge.svg?version=3.5.1)](https://docs.rs/actix-http/3.5.1)
 ![Version](https://img.shields.io/badge/rustc-1.68+-ab6000.svg)
 ![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-http.svg)
 <br />
-[![dependency status](https://deps.rs/crate/actix-http/3.5.0/status.svg)](https://deps.rs/crate/actix-http/3.5.0)
+[![dependency status](https://deps.rs/crate/actix-http/3.5.1/status.svg)](https://deps.rs/crate/actix-http/3.5.1)
 [![Download](https://img.shields.io/crates/d/actix-http.svg)](https://crates.io/crates/actix-http)
 [![Chat on Discord](https://img.shields.io/discord/771444961383153695?label=chat&logo=discord)](https://discord.gg/NWpN5mmg3x)
 

actix-http/src/encoding/encoder.rs

@@ -50,10 +50,21 @@ impl<B: MessageBody> Encoder<B> {
         }
     }
 
+    fn empty() -> Self {
+        Encoder {
+            body: EncoderBody::Full { body: Bytes::new() },
+            encoder: None,
+            fut: None,
+            eof: true,
+        }
+    }
+
     pub fn response(encoding: ContentEncoding, head: &mut ResponseHead, body: B) -> Self {
-        // no need to compress an empty body
-        if matches!(body.size(), BodySize::None | BodySize::Sized(0)) {
-            return Self::none();
+        // no need to compress empty bodies
+        match body.size() {
+            BodySize::None => return Self::none(),
+            BodySize::Sized(0) => return Self::empty(),
+            _ => {}
         }
 
         let should_encode = !(head.headers().contains_key(&CONTENT_ENCODING)