Fix panic with invalid trailer

Author: tirr-c

src/chunked.rs

@@ -482,7 +482,9 @@ fn decode_trailer(buffer: Block<'static>, pos: &Range<usize>) -> io::Result<Deco
             let mut trailers = Trailers::new();
             for header in headers {
                 let value = std::string::String::from_utf8_lossy(header.value).to_string();
-                trailers.insert(header.name, value).unwrap();
+                if let Err(err) = trailers.insert(header.name, value) {
+                    return Err(io::Error::new(io::ErrorKind::Other, err.to_string()));
+                }
             }
 
             Ok(DecodeResult::Some {

tests/fixtures/request-invalid-trailer.txt

@@ -0,0 +1,8 @@
+GET / HTTP/1.1
+content-type: application/octet-stream
+transfer-encoding: chunked
+trailer: x-invalid
+
+0
+x-invalid: å
+

tests/fixtures/response-invalid-trailer.txt

@@ -99,3 +99,29 @@ async fn test_unexpected_eof() {
 
     case.assert().await;
 }
+
+#[async_std::test]
+async fn test_invalid_trailer() {
+    let case = TestCase::new_server(
+        "fixtures/request-invalid-trailer.txt",
+        "fixtures/response-invalid-trailer.txt",
+    )
+    .await;
+    let addr = "http://example.com";
+
+    async_h1::accept(addr, case.clone(), |req| async {
+        let mut resp = Response::new(StatusCode::Ok);
+        let ct = req.content_type();
+        let body: Body = req.into();
+        resp.set_body(body);
+        if let Some(ct) = ct {
+            resp.set_content_type(ct);
+        }
+
+        Ok(resp)
+    })
+    .await
+    .unwrap_err();
+
+    assert!(case.read_result().await.is_empty());
+}