Fix #4760 "Missing children when svnadmin dump --include/exclude converts copy-dir to add-dir".
Follow-up to r1811992: Canonicalize PATH before passing it to the FILTER_FUNC.
In some cases (e.g. for nodes under copied directories) PATH passed by repos layer to AUTHZ_FUNC may be non-canonical (missing leading '/'). This causes FILTER_FUNC implemented in svnadmin to wrongly report PATH as "not included".
* subversion/libsvn_repos/dump.c (dump_filter_authz_func): Canonicalize PATH before passing it to the FILTER_FUNC. Add comment.
* subversion/tests/cmdline/svnadmin_tests.py (dump_include_copied_directory): New. (test_list): Add new test to table.