On 7 September 2015 at 18:06, <kot...@apache.org> wrote: > Author: kotkov > Date: Mon Sep 7 15:06:57 2015 > New Revision: 1701633 > > URL: http://svn.apache.org/r1701633 > Log: > Fix svn_stream_for_stdin() and related functions for STDOUT and STDERR > that were returning streams with mark() and seek() capabilities. > > STDIN, STDOUT and STDERR don't provide general support for positioning > requests. This behavior is implementation-specific and depends on what's > passed as the corresponding handle. For example, on Linux, apr_file_seek() > that calls lseek() internally fails with ESPIPE [1] when the descriptor is > associated with a terminal device. As we cannot safely advertise mark() > and seek() support for these streams, don't do that. > > [1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/lseek.html > > * subversion/libsvn_subr/stream.c > (svn_stream_for_stdin, svn_stream_for_stdout, svn_stream_for_stderr): > Don't install mark and seek handlers. > It may be worth to introduce local helper like 'make_stream_from_apr_file(svn_boolean_t supports_seek)' and use it in svn_stream_from_apr_file2() and svn_stream_for_stdin() instead of clearing mark/seek handlers after calling svn_stream_from_apr_file2().
Another problem that currently svn_stream_t for stdin/stderr/stdout pretends to support native svn_stream_skip(), while I'm not sure that all platforms support seek for stdin. -- Ivan Zhakov
