For issue #3826 ("`svn diff local_absolutepath` from inside a local working copy is broken"), fix its broken regression test.
For issue #3826 ("`svn diff local_absolutepath` from inside a local
working copy is broken"), fix its broken regression test.

* subversion/tests/cmdline/diff_tests.py
  (diff_abs_localpath_from_wc_folder): Calculate the absolute path of
    the 'B', which is relative to the current working directory,
    *before* chdir()'ing elsewhere.  This ensure that we have the
    *correct* absolute path for 'B'.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion