fix: content length assertion for HEAD

Author: 23doors

src/proto/h1/role.rs

@@ -701,7 +701,9 @@ impl Server {
                             // same to help developers find bugs.
                             #[cfg(debug_assertions)]
                             {
-                                if let Some(len) = headers::content_length_parse(&value) {
+                                if let Some(len) = headers::content_length_parse(&value)
+                                    && (msg.req_method != &Some(Method::HEAD) || known_len != 0)
+                                {
                                     assert!(
                                         len == known_len,
                                         "payload claims content-length of {}, custom content-length header claims {}",