jtidy version 7+svn20110807-2 failed to build with openjdk-7

During a rebuild test on precise with default-jdk switched to openjdk-7, a build failure was detected for jtidy version 7+svn20110807-2.

See attached log for full build failure details.

This log snippet might also be of interest:

[INFO]
NOTE: Maven is executing in offline mode. Any artifacts not already in your local
repository will be inaccessible.

[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building JTidy
[INFO] task-segment: [javadoc:jar]
[INFO] ------------------------------------------------------------------------
[INFO] [javadoc:jar {execution: default-cli}]
[WARNING] Source files encoding has not been set, using platform encoding ANSI_X3.4-1968, i.e. build is platform dependent!
[INFO]
4 errors
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] MavenReportException: Error while creating archive:
Exit code: 1 - /«BUILDDIR»/jtidy-7+svn20110807/src/main/java/org/w3c/tidy/Lexer.java:1281: error: unmappable character for encoding ANSI_X3.4-1968
                if (doctype != null)// #473490 - fix by Bj??rn H??hrmann 10 Oct 01
                                                          ^
/«BUILDDIR»/jtidy-7+svn20110807/src/main/java/org/w3c/tidy/Lexer.java:1281: error: unmappable character for encoding ANSI_X3.4-1968
                if (doctype != null)// #473490 - fix by Bj??rn H??hrmann 10 Oct 01
                                                           ^
/«BUILDDIR»/jtidy-7+svn20110807/src/main/java/org/w3c/tidy/Lexer.java:1281: error: unmappable character for encoding ANSI_X3.4-1968
                if (doctype != null)// #473490 - fix by Bj??rn H??hrmann 10 Oct 01
                                                                ^
/«BUILDDIR»/jtidy-7+svn20110807/src/main/java/org/w3c/tidy/Lexer.java:1281: error: unmappable character for encoding ANSI_X3.4-1968
                if (doctype != null)// #473490 - fix by Bj??rn H??hrmann 10 Oct 01
                                                                 ^

Command line was: /usr/lib/jvm/java-7-openjdk-amd64/jre/../bin/javadoc @options @packages

Refer to the generated Javadoc files in '/«BUILDDIR»/jtidy-7+svn20110807/target/apidocs' dir.

[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 6 seconds
[INFO] Finished at: Thu Nov 10 01:15:35 UTC 2011
[INFO] Final Memory: 17M/273M
[INFO] ------------------------------------------------------------------------
make: *** [debian/stamp-maven-doc] Error 1
dpkg-buildpackage: error: debian/rules build gave error exit status 2
────────────────────────────────────────────────────────────────────────────────
Build finished at 20111110-0115

Finished
────────

E: Build failure (dpkg-buildpackage died)