Fix AcceptEncoding header (#2501)

actix-http/src/header/map.rs

@@ -605,6 +605,13 @@ impl<'a> IntoIterator for &'a HeaderMap {
     }
 }
 
+/// Convert `http::HeaderMap` to our `HeaderMap`.
+impl From<http::HeaderMap> for HeaderMap {
+    fn from(mut map: http::HeaderMap) -> HeaderMap {
+        HeaderMap::from_drain(map.drain())
+    }
+}
+
 /// Iterator over removed, owned values with the same associated name.
 ///
 /// Returned from methods that remove or replace items. See [`HeaderMap::insert`]

actix-http/src/header/mod.rs

@@ -57,13 +57,6 @@ pub trait Header: TryIntoHeaderValue {
     fn parse<M: HttpMessage>(msg: &M) -> Result<Self, ParseError>;
 }
 
-/// Convert `http::HeaderMap` to our `HeaderMap`.
-impl From<http::HeaderMap> for HeaderMap {
-    fn from(mut map: http::HeaderMap) -> HeaderMap {
-        HeaderMap::from_drain(map.drain())
-    }
-}
-
 /// This encode set is used for HTTP header values and is defined at
 /// <https://datatracker.ietf.org/doc/html/rfc5987#section-3.2>.
 pub(crate) const HTTP_VALUE: &AsciiSet = &CONTROLS

actix-http/src/header/shared/content_encoding.rs

@@ -20,14 +20,16 @@ pub struct ContentEncodingParseError;
 /// See [IANA HTTP Content Coding Registry].
 ///
 /// [IANA HTTP Content Coding Registry]: https://www.iana.org/assignments/http-parameters/http-parameters.xhtml
-#[derive(Debug, Clone, Copy, PartialEq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 #[non_exhaustive]
 pub enum ContentEncoding {
-    /// Automatically select encoding based on encoding negotiation.
-    Auto,
+    /// Indicates the no-op identity encoding.
+    ///
+    /// I.e., no compression or modification.
+    Identity,
 
     /// A format using the Brotli algorithm.
-    Br,
+    Brotli,
 
     /// A format using the zlib structure with deflate algorithm.
     Deflate,
@@ -37,27 +39,30 @@ pub enum ContentEncoding {
 
     /// Zstd algorithm.
     Zstd,
-
-    /// Indicates the identity function (i.e. no compression, nor modification).
-    Identity,
 }
 
 impl ContentEncoding {
-    /// Is the content compressed?
-    #[inline]
-    pub const fn is_compression(self) -> bool {
-        matches!(self, ContentEncoding::Identity | ContentEncoding::Auto)
-    }
-
     /// Convert content encoding to string.
     #[inline]
     pub const fn as_str(self) -> &'static str {
         match self {
-            ContentEncoding::Br => "br",
+            ContentEncoding::Brotli => "br",
             ContentEncoding::Gzip => "gzip",
             ContentEncoding::Deflate => "deflate",
             ContentEncoding::Zstd => "zstd",
-            ContentEncoding::Identity | ContentEncoding::Auto => "identity",
+            ContentEncoding::Identity => "identity",
+        }
+    }
+
+    /// Convert content encoding to header value.
+    #[inline]
+    pub const fn to_header_value(self) -> HeaderValue {
+        match self {
+            ContentEncoding::Brotli => HeaderValue::from_static("br"),
+            ContentEncoding::Gzip => HeaderValue::from_static("gzip"),
+            ContentEncoding::Deflate => HeaderValue::from_static("deflate"),
+            ContentEncoding::Zstd => HeaderValue::from_static("zstd"),
+            ContentEncoding::Identity => HeaderValue::from_static("identity"),
         }
     }
 }
@@ -71,16 +76,18 @@ impl Default for ContentEncoding {
 impl FromStr for ContentEncoding {
     type Err = ContentEncodingParseError;
 
-    fn from_str(val: &str) -> Result<Self, Self::Err> {
-        let val = val.trim();
+    fn from_str(enc: &str) -> Result<Self, Self::Err> {
+        let enc = enc.trim();
 
-        if val.eq_ignore_ascii_case("br") {
-            Ok(ContentEncoding::Br)
-        } else if val.eq_ignore_ascii_case("gzip") {
+        if enc.eq_ignore_ascii_case("br") {
+            Ok(ContentEncoding::Brotli)
+        } else if enc.eq_ignore_ascii_case("gzip") {
             Ok(ContentEncoding::Gzip)
-        } else if val.eq_ignore_ascii_case("deflate") {
+        } else if enc.eq_ignore_ascii_case("deflate") {
             Ok(ContentEncoding::Deflate)
-        } else if val.eq_ignore_ascii_case("zstd") {
+        } else if enc.eq_ignore_ascii_case("identity") {
+            Ok(ContentEncoding::Identity)
+        } else if enc.eq_ignore_ascii_case("zstd") {
             Ok(ContentEncoding::Zstd)
         } else {
             Err(ContentEncodingParseError)

actix-http/src/header/shared/quality.rs

@@ -27,7 +27,8 @@ const MAX_QUALITY_FLOAT: f32 = 1.0;
 ///
 /// assert_eq!(q(0.42).to_string(), "0.42");
 /// assert_eq!(q(1.0).to_string(), "1");
-/// assert_eq!(Quality::MIN.to_string(), "0");
+/// assert_eq!(Quality::MIN.to_string(), "0.001");
+/// assert_eq!(Quality::ZERO.to_string(), "0");
 /// ```
 ///
 /// [RFC 7231 §5.3.1]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.1
@@ -38,8 +39,11 @@ impl Quality {
     /// The maximum quality value, equivalent to `q=1.0`.
     pub const MAX: Quality = Quality(MAX_QUALITY_INT);
 
-    /// The minimum quality value, equivalent to `q=0.0`.
-    pub const MIN: Quality = Quality(0);
+    /// The minimum, non-zero quality value, equivalent to `q=0.001`.
+    pub const MIN: Quality = Quality(1);
+
+    /// The zero quality value, equivalent to `q=0.0`.
+    pub const ZERO: Quality = Quality(0);
 
     /// Converts a float in the range 0.0–1.0 to a `Quality`.
     ///
@@ -51,7 +55,7 @@ impl Quality {
         // Check that `value` is within range should be done before calling this method.
         // Just in case, this debug_assert should catch if we were forgetful.
         debug_assert!(
-            (0.0f32..=1.0f32).contains(&value),
+            (0.0..=MAX_QUALITY_FLOAT).contains(&value),
             "q value must be between 0.0 and 1.0"
         );
 
@@ -154,10 +158,13 @@ impl TryFrom<f32> for Quality {
 /// let q1 = q(1.0);
 /// assert_eq!(q1, Quality::MAX);
 ///
-/// let q2 = q(0.0);
+/// let q2 = q(0.001);
 /// assert_eq!(q2, Quality::MIN);
 ///
-/// let q3 = q(0.42);
+/// let q3 = q(0.0);
+/// assert_eq!(q3, Quality::ZERO);
+///
+/// let q4 = q(0.42);
 /// ```
 ///
 /// An out-of-range `f32` quality will panic.
@@ -185,6 +192,10 @@ mod tests {
 
     #[test]
     fn display_output() {
+        assert_eq!(Quality::ZERO.to_string(), "0");
+        assert_eq!(Quality::MIN.to_string(), "0.001");
+        assert_eq!(Quality::MAX.to_string(), "1");
+
         assert_eq!(q(0.0).to_string(), "0");
         assert_eq!(q(1.0).to_string(), "1");
         assert_eq!(q(0.001).to_string(), "0.001");

actix-http/src/header/shared/quality_item.rs

@@ -31,7 +31,7 @@ use super::Quality;
 /// let q_item_fallback: QualityItem<String> = "abc;q=0.1".parse().unwrap();
 /// assert!(q_item > q_item_fallback);
 /// ```
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct QualityItem<T> {
     /// The wrapped contents of the field.
     pub item: T,
@@ -53,10 +53,15 @@ impl<T> QualityItem<T> {
         Self::new(item, Quality::MAX)
     }
 
-    /// Constructs a new `QualityItem` from an item, using the minimum q-value.
+    /// Constructs a new `QualityItem` from an item, using the minimum, non-zero q-value.
     pub fn min(item: T) -> Self {
         Self::new(item, Quality::MIN)
     }
+
+    /// Constructs a new `QualityItem` from an item, using zero q-value of zero.
+    pub fn zero(item: T) -> Self {
+        Self::new(item, Quality::ZERO)
+    }
 }
 
 impl<T: PartialEq> PartialOrd for QualityItem<T> {
@@ -73,7 +78,10 @@ impl<T: fmt::Display> fmt::Display for QualityItem<T> {
             // q-factor value is implied for max value
             Quality::MAX => Ok(()),
 
-            Quality::MIN => f.write_str("; q=0"),
+            // fast path for zero
+            Quality::ZERO => f.write_str("; q=0"),
+
+            // quality formatting is already using itoa
             q => write!(f, "; q={}", q),
         }
     }