Fix Issue #4400: commits fail with copy and deep delete under copy. * subversion/libsvn_ra_serf/commit.c (checkout_dir): Generate the working_url when a parent is added by combining the add parent's working_url and the unique (vs add parent) portion of the checkout directory's relpath. * subversion/tests/cmdline/commit_tests.py (commit_cp_with_deep_delete): Remove the XFail decorator from the test which will pass now.