fix(files): handle `bytes=0-` nicely (#3914)

actix-files/CHANGES.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Add `Files::try_compressed()` to support serving pre-compressed static files [#2615]
+- Fix handling of `bytes=0-`
 
 [#2615]: https://github.com/actix/actix-web/pull/2615
 

actix-files/src/lib.rs

@@ -513,6 +513,30 @@ mod tests {
         assert_eq!(content_range.to_str().unwrap(), "bytes */100");
     }
 
+    #[actix_rt::test]
+    async fn test_named_file_range_header_from_zero_to_end_returns_partial_content() {
+        let srv = actix_test::start(|| App::new().service(Files::new("/", ".")));
+
+        let response = srv
+            .get("/tests/test.binary")
+            .insert_header((header::RANGE, "bytes=0-"))
+            .send()
+            .await
+            .unwrap();
+
+        assert_eq!(response.status(), StatusCode::PARTIAL_CONTENT);
+
+        let content_range = response.headers().get(header::CONTENT_RANGE).unwrap();
+        assert_eq!(content_range.to_str().unwrap(), "bytes 0-99/100");
+
+        let content_length = response.headers().get(header::CONTENT_LENGTH).unwrap();
+        assert_eq!(content_length.to_str().unwrap(), "100");
+
+        // Should be no transfer-encoding
+        let transfer_encoding = response.headers().get(header::TRANSFER_ENCODING);
+        assert!(transfer_encoding.is_none());
+    }
+
     #[actix_rt::test]
     async fn test_named_file_content_length_headers() {
         let srv = actix_test::start(|| App::new().service(Files::new("/", ".")));

actix-files/src/named.rs

@@ -550,6 +550,7 @@ impl NamedFile {
 
         let mut length = self.md.len();
         let mut offset = 0;
+        let mut ranged_req = false;
 
         // check for range header
         if let Some(ranges) = req.headers().get(header::RANGE) {
@@ -558,6 +559,7 @@ impl NamedFile {
                     .ok()
                     .and_then(|ranges| ranges.first().copied())
                 {
+                    ranged_req = true;
                     length = range.length;
                     offset = range.start;
 
@@ -606,7 +608,7 @@ impl NamedFile {
 
         let reader = chunked::new_chunked_read(length, offset, self.file, self.read_mode_threshold);
 
-        if offset != 0 || length != self.md.len() {
+        if ranged_req {
             res.status(StatusCode::PARTIAL_CONTENT);
         }