Description

The cas-auth plugin assembles the CAS service parameter (the callback URL sent to the CAS identity provider) from the request scheme, Host header and port plus cas_callback_uri.

This PR lets operators configure cas_callback_uri as an absolute URL. When it is absolute (matches ^https?://), it is used verbatim as the CAS service URL and the request-derived construction is skipped. The relative-path form keeps its existing behaviour, and check_schema logs a warning at config-load time when the relative form is used so operators are aware the service URL is derived from the request Host header.

The callback path matched against ctx.var.uri for incoming IdP callbacks is now derived from cas_callback_uri, so matching keeps working when an absolute URL is configured.

New cases in t/plugin/cas-auth.t cover the absolute-URL form, the relative-path form, and the path-derivation helper.

This change is backward compatible: existing relative-path configurations behave exactly as before.

Which issue(s) this PR fixes:

N/A

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible