Execute the user supplied diff3 with full environment because it's not possible to use an X11 program without it, and also for consistency with how a user supplied diff is executed.
Execute the user supplied diff3 with full environment because it's not
possible to use an X11 program without it, and also for consistency
with how a user supplied diff is executed.

* subversion/libsvn_subr/io.c
  (svn_io_run_diff3): Tell svn_io_run_cmd to keep the environment.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@850964 13f79535-47bb-0310-9956-ffa450edef68

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