Test for trialing slashes in value for 'issuer' from '/.well-known/openid-configuration' responses

Basically our ESS Brokers are advertising themselves (in their /.well-known/openid-configuration responses) as issuers with a trailing slash, e.g. for https://broker.pod.inrupt.com/.well-known/openid-configuration:

{
    "introspection_endpoint": "https://broker.pod.inrupt.com/introspect",
    "scopes_supported": [
        "openid",
        "offline_access",
        "webid"
    ],
    "issuer": "https://broker.pod.inrupt.com/",
    :

Note the trailing slash on the issuer URL (which is technically (slightly!) more correct than having the URL without the trailing slash).
So it seems NSS might be blindly taking that issuer value, and appending the string literal /.well-known/openid-configuration to it, without first checking if the issuer value has a trailing slash or not. If the URL constructed has two slashes, then the server responds with it’s standard HTML ‘Page Not Found’ response, which results in the ‘invalid json response…’ error.

If this is correct, then the fix in NSS should be simply checking for a trailing slash before appending /.well-known/openid-configuration.

Bắt đầu bằng cách xác định đoạn mã xây dựng URL /.well-known/openid-configuration từ issuer được trả về bởi phản hồi cấu hình OpenID. Bổ sung coverage cho các giá trị issuer có và không có dấu gạch chéo ở cuối, đồng thời xác nhận rằng cả hai đều tạo ra một URL hợp lệ với chỉ một dấu gạch chéo, thay vì một phản hồi JSON không hợp lệ.