Fix a bug in svn patch which prevented empty lines of context from matching.
Fix a bug in svn patch which prevented empty lines of context from matching.

* subversion/libsvn_client/patch.c
  (match_hunk): Some time ago, lines read from a hunk used to include
   the leading '-', ' ', or '+' character. But nowadays the diff-parser
   abstracts those away for us, so it's fine if a line read from a hunk
   has length zero.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@895508 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion