test failure in test_writers/test_manpage.py

Dear Engelbert,

it seems the latest commit(s) introduced a problem with the manpage writer
test:


    FAIL: test_reference_macros (test_writers.test_manpage.WriterPublishTestCase.test_reference_macros) (id="totest_refs['ext hyperlink'][0]")
    ----------------------------------------------------------------------
    Traceback (most recent call last):
      File "/usr/local/src/docutils-git-svn/docutils/test/test_writers/test_manpage.py", line 72, in test_reference_macros
        self.assertEqual(case_expected, output)
    AssertionError: '.\\"[850 chars]ike \n.UR https://www.python.org/\nPython\n.UE[37 chars]e.\n' != '.\\"[850 chars]ike \\c\n.UR https://www.python.org/\nPython\n[40 chars]e.\n'
      .\" Man page generated from reStructuredText by manpage writer
      .\" from docutils 0.22b.dev.
      . 

[...]

      .TH "" "" "" ""
      .SH Name
       \- 
    - embedded External hyperlinks, like 
    + embedded External hyperlinks, like \c
    ?                                    ++
      .UR https://www.python.org/
      Python
      .UE
      \&.
      .\" End of generated man page.
    
    
    ----------------------------------------------------------------------
    Ran 2389 tests in 4.538s
    
    FAILED (failures=2, skipped=5)

Could you have a look?