JavaHL: Fix potential segfault in merge info retrieval API, which can crash a JVM.  The was caused by changes in Subversion's core APIs which were not tracked by the JavaHL bindings.
JavaHL: Fix potential segfault in merge info retrieval API, which can
crash a JVM.  The was caused by changes in Subversion's core APIs
which were not tracked by the JavaHL bindings.

[ in subversion/bindings/javahl/ ]

* native/SVNClient.cpp
  (getMergeInfo): Return NULL when svn_client_get_mergeinfo() returns
   NULL merge info.

Found by: markphip
          hwright


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@865381 13f79535-47bb-0310-9956-ffa450edef68

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