Fix issue #4121: svnsync of a copy followed by delete of was-unreadable child.
Fix issue #4121: svnsync of a copy followed by delete of was-unreadable child.

* subversion/libsvn_repos/replay.c
  (was_readable): New helper.
  (path_driver_cb_func):
    Use new helper to determine whether to replay or discard deletions.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1293998 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion