On the 1.10-cache-improvement branch:
On the 1.10-cache-improvement branch:

* subversion/libsvn_subr/cache-membuffer.c
  (combine_key): Explain how important reversibility is on this optimized
                 code path.  No functional change.


git-svn-id: 9abecf2226429f900b686d5b950d6ce0235536c5@1681965 13f79535-47bb-0310-9956-ffa450edef68

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