URISyntaxException on Invalid URLs when @EnableOAuth2Client is present

[jcarvalho]

Description

When attempting to access a syntactically invalid URL (but allowed by the Browser), like /[], on a Spring application with the OAuth2 Client enabled (using @EnableOAuth2Client), an exception is thrown.

This seems to be caused by OAuth2ClientContextFilter use of ServletUriComponentsBuilder.fromRequest to compute the 'current URL', which is later used to implement AccessTokenRequest.getCurrentUri. As invalid URLs throw a URISyntaxException on fromRequest, an uncaught exception is raised, causing a 500 error.

Expected Behavior

The server returns a 4xx class error (like a 400 or a 404) or allows the filter chain to proceed.

Actual Behavior

The server returns a 500 error.

Steps to reproduce

1. Create a new Spring Boot app with Web and Cloud OAuth2
2. Add @EnableOAuth2Client to your app
3. Navigate to http://localhost:8080/[]

[gwfong]

We are encountering this as well. In fact, the Spring error handling like @ControllerAdvice, etc, is not catching the error. The 500 and the stack trace for us is being sent to the client.

Any ideas on how to handle it?

Looks like this issue might be related to this: https://jira.spring.io/browse/SPR-16414