OIDC token refresh causes NPE if no ID token is returned

[sberyozkin]

Describe the bug

Some OIDC providers do not return ID token in the refresh token grant response since it is optional in the OIDC spec, which causes NPE since Quarkus OIDC does expect it be returned as is done with Keycloak.

Expected behavior

If no ID token is returned - then if the previous ID token has not expired - use it, otherwise use the internally generated ID token which is the case now with the previous token claims minus iat and exp copied

Actual behavior

No response

How to Reproduce?

No response

Output of uname -a or ver

No response

Output of java -version

No response

GraalVM version (if different from Java)

No response

Quarkus version or git rev

No response

Build tool (ie. output of mvnw --version or gradlew --version)

No response

Additional information

No response

[quarkus-bot]

/cc @pedroigor

[DCCSKrezovic]

@sberyozkin I have a working prototype that I have tested in production-like scenarios. Should I submit a PR, or have you already done something?

[sberyozkin]

@DCCSKrezovic I've been working on it since yesterday, just about to open a PR; glad you are willing to help :-)