Fix a couple nits in the string-LCS algorithm.
Fix a couple nits in the string-LCS algorithm.

* subversion/libsvn_subr/string.c (svn_string__similarity): Fix the common
   suffix scanner, removing an edge-case bug, as per Julians most welcome
   suggestion. Also fix a string indexing bug (though I've no idea how that
   could've slipped past the test cases) and only initialize the part of the
   buffer that don't immediately overwrite..


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1412639 13f79535-47bb-0310-9956-ffa450edef68

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