NullPointerException when evaluating AuthLoginGroupSettingsUtil.isPromptEnabled

Issue

• The following error is thrown in the logs every once in a while:
  

  2024-07-29 06:55:37.018 ERROR [http-nio-8080-exec-7][CTCollectionPreviewFilter:53] java.lang.NullPointerException
  java.lang.NullPointerException: null
      at com.liferay.portal.kernel.login.AuthLoginGroupSettingsUtil.isPromptEnabled(AuthLoginGroupSettingsUtil.java:19) ~[portal-kernel.jar:?]
      at com.liferay.friendly.url.internal.servlet.FriendlyURLServlet.getRedirect(FriendlyURLServlet.java:234) ~[?:?]
      [...]

Environment

• Quarterly Release 2024.Q1

Resolution

• This problem can occur if the whole OSGI module (aka bundle) login-web is blacklisted.
• Blacklisting whole modules instead of specific components, if possible, can bring unintended behaviors like the error above.
• In this case, the module login-web contains an implementation of the interface AuthLoginGroupSettings that is needed when invoking AuthLoginGroupSettingsUtil.isPromptEnabled.
• Instead of blacklisting the whole module, consider blacklisting specific components within it. In particular, avoid blacklisting AuthLoginGroupSettingsImpl.

Additional Information

• Blacklisting OSGi Components
• Blacklisting Apps
• How to Login after Blacklisting the Sign-In Portlet