libjxmpp-java: FTBFS with default Java 21

[Vladimir Petko]

The package libjxmpp-java ftbfs with default Java 21.
The relevant part of the build log:
---------------
Putting task artifact state for task ':jxmpp-core:debianMavenPom' into context took 0.0 secs.
Up-to-date check for task ':jxmpp-core:debianMavenPom' took 0.0 secs. It is not up-to-date because:
  No history is available.
 Generating pom file /<<PKGBUILDDIR>>/jxmpp-jid/build/debian/jxmpp-jid.pom
 Generating pom file /<<PKGBUILDDIR>>/jxmpp-stringprep-icu4j/build/debian/jxmpp-stringprep-icu4j.pom
 Generating pom file /<<PKGBUILDDIR>>/jxmpp-core/build/debian/jxmpp-core.pom
:jxmpp-jid:debianMavenPom (Thread[#43,Task worker for ':' Thread 3,5,main]) completed. Took 0.052 secs.
:jxmpp-stringprep-icu4j:debianMavenPom (Thread[#41,Task worker for ':',5,main]) completed. Took 0.055 secs.
:jxmpp-core:debianMavenPom (Thread[#42,Task worker for ':' Thread 2,5,main]) completed. Took 0.057 secs.
/<<PKGBUILDDIR>>/jxmpp-util-cache/src/main/java/org/jxmpp/util/cache/ExpirationCache.java:38: warning: [this-escape] possible 'this' escape before subclass is fully initialized
  setDefaultExpirationTime(defaultExpirationTime);
                          ^
error: warnings found and -Werror specified
1 error
1 warning
:jxmpp-util-cache:compileJava FAILED
:jxmpp-util-cache:compileJava (Thread[#29,Daemon worker,5,main]) completed. Took 0.487 secs.

FAILURE: Build failed with an exception.

[Vladimir Petko (vpa1977)]

piuparts install/upgrade/purge test (pass)

[Launchpad Janitor (janitor)]

This bug was fixed in the package libjxmpp-java - 1.0.1-3ubuntu1

---------------
libjxmpp-java (1.0.1-3ubuntu1) noble; urgency=medium

  * d/p/02-avoid-this-escape.patch: apply upstream fix to resolve Java
    21 ftbfs (LP: #2054240).

 -- Vladimir Petko <email address hidden> Mon, 19 Feb 2024 10:07:15 +1300