Updates-Via header in OPTIONS

The Solid WebSocket API Specs say that Updates-Via header can be found in an OPTIONS request to the server.

I am not finding an Updates-Via header in OPTIONS for node solid server, though I do get one if I do an HTTP HEAD:

$ curl -k -i  -X OPTIONS https://localhost:8443/public/
HTTP/1.1 204 No Content
X-Powered-By: solid-server/5.1.2
Vary: Accept, Authorization, Origin, Access-Control-Request-Headers
Access-Control-Allow-Credentials: true
Access-Control-Allow-Methods: OPTIONS,HEAD,GET,PATCH,POST,PUT,DELETE
Access-Control-Max-Age: 1728000
Access-Control-Expose-Headers: Authorization, User, Location, Link, Vary, Last-Modified, ETag, Accept-Patch, Accept-Post, Updates-Via, Allow, WAC-Allow, Content-Length, WWW-Authenticate
Allow: COPY,GET,HEAD,POST,PATCH,PUT,DELETE
Link: <https://localhost:8443/public/.well-known/solid>; rel="service", <https://localhost:8443>; rel="http://openid.net/specs/connect/1.0/issuer", <.acl>; rel="acl", <.meta>; rel="describedBy", <http://www.w3.org/ns/ldp#Container>; rel="type", <http://www.w3.org/ns/ldp#BasicContainer>; rel="type"
Accept-Patch: application/sparql-update
Accept-Post: */*
ETag: W/"23-dYHCBqdZ5e1V1nWlG0I6iB9SOvk"
Date: Wed, 05 Jun 2019 20:57:22 GMT
Connection: keep-alive

vs

$ curl -k --head https://localhost:8443/public/
HTTP/1.1 200 OK
X-Powered-By: solid-server/5.1.2
Vary: Accept, Authorization, Origin
Access-Control-Allow-Credentials: true
Access-Control-Expose-Headers: Authorization, User, Location, Link, Vary, Last-Modified, ETag, Accept-Patch, Accept-Post, Updates-Via, Allow, WAC-Allow, Content-Length, WWW-Authenticate
Allow: OPTIONS, HEAD, GET, PATCH, POST, PUT, DELETE
Link: <.acl>; rel="acl", <.meta>; rel="describedBy", <http://www.w3.org/ns/ldp#Container>; rel="type", <http://www.w3.org/ns/ldp#BasicContainer>; rel="type"
MS-Author-Via: SPARQL
Updates-Via: wss://localhost:8443
Content-Type: application/octet-stream; charset=utf-8
Content-Length: 2
ETag: W/"2-nOO9QiTIwXgNtWtBJezz8kv3SLc"
Date: Wed, 05 Jun 2019 20:57:00 GMT
Connection: keep-alive

This is using v5.1.2

Bắt đầu bằng cách xác định phần xử lý yêu cầu cho các phản hồi OPTIONS và HEAD, đồng thời tìm phần tạo header Updates-Via. Tái hiện sự khác biệt bằng các lệnh curl trong issue đối với phiên bản server bị ảnh hưởng, sau đó xác minh rằng hành vi header mong đợi là nhất quán đối với cả hai phương thức.