Put jcorvel's workaround for issue #4351 into mod_dav_svn's implementation.
Put jcorvel's workaround for issue #4351 into mod_dav_svn's implementation.

* subversion/mod_dav_svn/repos.c
  (get_resource): Set a Depth header with value "0" on copy requests.
   This prevents mod_dav's precondition check from recursing over the copy
   source tree and thus restores O(1) behaviour for 'svn copy' with current
   httpd releases.
   The alternative of patching mod_dav was also considered but has been
   dismissed. Ideally, there would be an API between mod_dav and its
   providers to enable/disable the precondition tree walk.

Patch by: me
          gstein


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1674627 13f79535-47bb-0310-9956-ffa450edef68

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