No method for nil value exception in token introspection

[linhdangduy]

Steps to reproduce

After update code with #1209 pull request (on master branch or tags v5.1.0rc2), send a request to token introspection endpoint with following format:

POST /oauth/introspect HTTP/1.1
Header: Authorization = Bearer bearer_access_token
Body: token=Wrong_token (just set a random token)

Expected behavior

Because body's token was wrong, expected response is

{ "active": false }

Actual behavior

Exception occurred: No method .token for nil value. At the following line

doorkeeper/lib/doorkeeper/oauth/token_introspection.rb

Line 166 in 9bb03f8

authorized_token.token == @token.token

Reason

@token is gotten from request's param at these line

doorkeeper/app/controllers/doorkeeper/tokens_controller.rb

Lines 77 to 80 in 9bb03f8

	def token
	@token ||= AccessToken.by_token(params["token"]) ||
	AccessToken.by_refresh_token(params["token"])
	end

In case token is wrong, it will be nil. So the exception will occurred.

System configuration

Using doorkeeper on master branch or tags v5.1.0rc2.

[nbulaj]

Fixed by #1243