Fix incorrect LargeResponseHeader

src/lib.rs

@@ -1132,6 +1132,18 @@ pub(crate) mod test {
         ensure!(Body, 700); // 648
     }
 
+    #[test]
+    fn limit_max_response_header_size() {
+        init_test_log();
+        let err = get("http://httpbin.org/get")
+            .config()
+            .max_response_header_size(5)
+            .build()
+            .call()
+            .unwrap_err();
+        assert!(matches!(err, Error::LargeResponseHeader(65, 5)));
+    }
+
     // This doesn't need to run, just compile.
     fn _ensure_send_sync() {
         fn is_send(_t: impl Send) {}

src/run.rs

@@ -529,7 +529,17 @@ fn recv_response(
 
         let (amount, maybe_response) = flow.try_response(input, allow_partial_redirect)?;
 
-        if input.len() > config.max_response_header_size() {
+        let check_size = if maybe_response.is_some() {
+            // We got a parsed response, ensure the size is within
+            // configured parameters.
+            amount
+        } else {
+            // We did not parse a response, if input is too large,
+            // we stop trying to get more data.
+            input.len()
+        };
+
+        if check_size > config.max_response_header_size() {
             return Err(Error::LargeResponseHeader(
                 input.len(),
                 config.max_response_header_size(),