Fix a bug in the pre-0.14 dumpstream parsing code. Correctly handle file modification to contain no content. Followup to r12075
Fix a bug in the pre-0.14 dumpstream parsing code. Correctly handle file
modification to contain no content. Followup to r12075

* subversion/libsvn_repos/load.c (svn_repos_parse_dumpstream2): When an old-v1
    dumpstream block is detected with zero bytes of content after the property
    block, correctly deduce whether this is an empty text block or an absent
    text block.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@852522 13f79535-47bb-0310-9956-ffa450edef68

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