fix(axum-core): skip non-data frames in BytesMut (#3811)

axum-core/CHANGELOG.md

@@ -14,9 +14,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **changed:** `impl IntoResponse for ()` (which gets called by
   `impl IntoResponse for HeaderMap`, `impl IntoResponse for Extensions` and
   others) now returns a body of unknown size.
+- **fixed:** Make the `BytesMut` extractor ignore non-data frames from custom
+  request bodies, matching the `Bytes` extractor ([#3811])
 
 [#3721]: https://github.com/tokio-rs/axum/pull/3721
 [#3742]: https://github.com/tokio-rs/axum/pull/3742
+[#3811]: https://github.com/tokio-rs/axum/pull/3811
 
 # 0.5.6
 

axum-core/src/extract/request_parts.rs

@@ -89,7 +89,8 @@ async fn body_to_bytes_mut(body: &mut Body, bytes: &mut BytesMut) -> Result<(),
         .map_err(FailedToBufferBody::from_err)?
     {
         let Ok(data) = frame.into_data() else {
-            return Ok(());
+            // Match `Bytes` by ignoring non-data frames until the body ends.
+            continue;
         };
         bytes.put(data);
     }