Skip dropping request on code request parameter

[ricristian]

By default if someone makes a GET request with parameter &code=... after authentication against IdP
classic error request to the redirect_uri path but there's no session state found will be raised.

I believe that it's related to

local function openidc_get_path(uri)
  local without_query = uri:match("(.-)%?") or uri
  return without_query:match(".-//[^/]+(/.*)") or without_query
end

Where basically &code matches the regex which triggers authorization response from OP.

&code= alone without extra request parameter should be treated as authorization response ?

Eventough I don't believe that this is a viable solution but the issue seems to be present

[oldium]

That is not how it works. openidc_get_path just strips the ?query_parameters part from the URI. The code which switches to the response handling part is this:

  local path = openidc_get_path(target_url)
  if path == openidc_get_redirect_uri_path(opts) then
    log(DEBUG, "Redirect URI path (" .. path .. ") is currently navigated -> Processing authorization response coming from OP")
    ...

Maybe your redirect_uri simply conflicts with regular client requests?