RESTful API handler: wrong link URL generated for to-one relationship

[ymc9]

curl -g 'localhost:3000/api/post?filter[published]=true&sort=-createdAt'

{
   "data" : [
      {
         "attributes" : {
            "authorId" : 5,
            "createdAt" : "2023-06-06T12:23:17.130Z",
            "published" : true,
            "title" : "How to build a RESTful API in 15 minutes",
            "updatedAt" : "2023-06-06T12:23:17.130Z",
            "viewCount" : 0
         },
         "id" : 14,
         "links" : {
            "self" : "http://localhost:3000/api/post/14"
         },
         "relationships" : {
            "author" : {
               "data" : {
                  "id" : 5,
                  "type" : "user"
               },
               "links" : {
                  "related" : "http://localhost:3000/api/post/14/author/5",
                  "self" : "http://localhost:3000/api/post/14/relationships/author/5"
               }
            }
         },
         "type" : "post"
      }]
}