Apply some tweaks to svn_io_file_create*() after r1505006. Resolve a regression on writing a NULL buffer.
Apply some tweaks to svn_io_file_create*() after r1505006. Resolve a regression
on writing a NULL buffer.

* subversion/libsvn_subr/io.c
  (svn_io_file_create_binary): Try to delete the file we created on error
    writing it. Use standard notation for function prototype.

  (svn_io_file_create): Resolve regression introduced in r1505006, where a
    NULL contents of 0 length would previously not segfault, but now will.
    Use standard notation for function prototype.

  (svn_io_file_create,
   svn_io_dir_file_copy): Use standard notation for function prototype.
     Add svn_error_trace.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1505219 13f79535-47bb-0310-9956-ffa450edef68

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