Provide a way for svnserve's 'get-deleted-rev' API to return 'not deleted'.
Previously the answer 'not deleted' was indistinguishable from an error when using the svnserve protocol.
The standard 'svn' client software does not appear to invoke this case, but it is meant to be a valid answer and is supported by the other repository access protocols.
To work around the problem without changing the protocol, we re-purpose the obsolete error code 'SVN_ERR_ENTRY_MISSING_REVISION' to communicate this 'not deleted' reply to the client.
(Re-purposing an old error code was not essential. An alternative would be to create a new error code which would become part of the public API in the next minor release, but would be deemed non-public when backported to older release lines.)
- With a new client against a new server, such queries are now handled correctly.
- With an old client against a new server, the client will report a more informative error message.
- With a new client against an old server, there is no improvement.
* subversion/svnserve/serve.c (get_deleted_rev): If the answer is SVN_INVALID_REVNUM, return a SVN_ERR_ENTRY_MISSING_REVISION error to the client.
* subversion/libsvn_ra_svn/client.c (ra_svn_get_deleted_rev): Convert the error SVN_ERR_ENTRY_MISSING_REVISION back to a response of SVN_INVALID_REVNUM.
* subversion/tests/libsvn_ra/ra-test.c (commit_two_changes): New. (test_get_deleted_rev_no_delete, test_get_deleted_rev_errors): New tests. (test_funcs): Run them.