Remove the usage of content-encoding identity header, disallow compression for partial content in general

actix-files/src/named.rs

@@ -534,27 +534,6 @@ impl NamedFile {
                     length = ranges[0].length;
                     offset = ranges[0].start;
 
-                    // When a Content-Encoding header is present in a 206 partial content response
-                    // for video content, it prevents browser video players from starting playback
-                    // before loading the whole video and also prevents seeking.
-                    //
-                    // See: https://github.com/actix/actix-web/issues/2815
-                    //
-                    // The assumption of this fix is that the video player knows to not send an
-                    // Accept-Encoding header for this request and that downstream middleware will
-                    // not attempt compression for requests without it.
-                    //
-                    // TODO: Solve question around what to do if self.encoding is set and partial
-                    // range is requested. Reject request? Ignoring self.encoding seems wrong, too.
-                    // In practice, it should not come up.
-                    if req.headers().contains_key(&header::ACCEPT_ENCODING) {
-                        // don't allow compression middleware to modify partial content
-                        res.insert_header((
-                            header::CONTENT_ENCODING,
-                            HeaderValue::from_static("identity"),
-                        ));
-                    }
-
                     res.insert_header((
                         header::CONTENT_RANGE,
                         format!("bytes {}-{}/{}", offset, offset + length - 1, self.md.len()),

actix-files/tests/encoding.rs

@@ -35,31 +35,3 @@ async fn test_utf8_file_contents() {
         Some(&HeaderValue::from_static("text/plain")),
     );
 }
-
-#[actix_web::test]
-async fn partial_range_response_encoding() {
-    let srv = test::init_service(App::new().default_service(web::to(|| async {
-        NamedFile::open_async("./tests/test.binary").await.unwrap()
-    })))
-    .await;
-
-    // range request without accept-encoding returns no content-encoding header
-    let req = TestRequest::with_uri("/")
-        .append_header((header::RANGE, "bytes=10-20"))
-        .to_request();
-    let res = test::call_service(&srv, req).await;
-    assert_eq!(res.status(), StatusCode::PARTIAL_CONTENT);
-    assert!(!res.headers().contains_key(header::CONTENT_ENCODING));
-
-    // range request with accept-encoding returns a content-encoding header
-    let req = TestRequest::with_uri("/")
-        .append_header((header::RANGE, "bytes=10-20"))
-        .append_header((header::ACCEPT_ENCODING, "identity"))
-        .to_request();
-    let res = test::call_service(&srv, req).await;
-    assert_eq!(res.status(), StatusCode::PARTIAL_CONTENT);
-    assert_eq!(
-        res.headers().get(header::CONTENT_ENCODING).unwrap(),
-        "identity"
-    );
-}

actix-http/src/encoding/encoder.rs

@@ -70,6 +70,7 @@ impl<B: MessageBody> Encoder<B> {
         let should_encode = !(head.headers().contains_key(&CONTENT_ENCODING)
             || head.status == StatusCode::SWITCHING_PROTOCOLS
             || head.status == StatusCode::NO_CONTENT
+            || head.status == StatusCode::PARTIAL_CONTENT
             || encoding == ContentEncoding::Identity);
 
         let body = match body.try_into_bytes() {