Following up on r1701633, do not use a custom svn_stream_skip() handler in streams that wrap STDIN, STDOUT and STDERR.
Following up on r1701633, do not use a custom svn_stream_skip() handler in
streams that wrap STDIN, STDOUT and STDERR.

This handler, skip_handler_apr(), performs a seek internally.  We cannot rely
on its behavior when wrapping standard I/O streams like STDIN, because they
do not generally support seeking.

Discussion can be found in http://svn.haxx.se/dev/archive-2015-09/0062.shtml
(Subject: "Re: svn commit: r1701633 - ...").

* subversion/libsvn_subr/stream.c
  (svn_stream_from_aprfile2): Extract the core of this function ...
  (make_stream_from_apr_file): ...into this new helper.  Add a new boolean
   argument that specifies whether we should install callbacks that depend
   on the ability to perform a seek().
  (svn_stream_for_stdin, svn_stream_for_stdout, svn_stream_for_stderr):
   Call the new helper while specifying that the handle does not support
   seeking.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1701792 13f79535-47bb-0310-9956-ffa450edef68

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