NameServerPool: prefer to return a NoRecordsFound response over a truncated non-error UDP response

crates/resolver/src/name_server/name_server_pool.rs

@@ -282,7 +282,12 @@ where
 
             let tcp_err = match tcp_res {
                 res @ Ok(..) => return res.map_err(ProtoError::from),
-                Err(e) => e,
+                Err(e) => match e.kind() {
+                    // a NoRecordsFound response contains more details than the truncated UDP
+                    // response, like additionals/nameservers
+                    ProtoErrorKind::NoRecordsFound { .. } => return Err(ProtoError::from(e)),
+                    _ => e,
+                }
             };
 
             // Even if the UDP result was truncated, return that