2003-06-09  Paolo Carlini  <pcarlini@unitus.it>

	* include/bits/fstream.tcc (_M_underflow): Do not special
	case the unbuffered case, which really means simply a one char
	get area.
	(basic_filebuf): Initialize _M_buf_size.
	(setbuf): Unbuffered means _M_buf_size == 1, since only
	_M_buf_size - 1 == 0 chars are going to be used for the
	put area and 1 for the get area.
	* include/std/std_streambuf.h (_M_buf_size): Move to basic_filebuf.
	(~basic_streambuf): Tweak.
	(basic_streambuf): Do not initialize _M_buf_size.
	* include/std/std_fstream.h (_M_buf_size): Add from basic_streambuf.
	(~basic_filebuf): Tweak.
	(_M_set_buffer): Tweak, considering that _M_buf_size == 1 is the
	unbuffered situation (i.e., put area pointers NULL).
	* include/bits/streambuf.tcc (sbumpc): Clean up.
	* testsuite/27_io/basic_filebuf/sputbackc/char/1.cc: Split into...
	* testsuite/27_io/basic_filebuf/sputbackc/char/1-in.cc: New.
	* testsuite/27_io/basic_filebuf/sputbackc/char/1-io.cc: New.
	* testsuite/27_io/basic_filebuf/sputbackc/char/1-out.cc: New.
	* testsuite/27_io/basic_filebuf/sputbackc/char/2-in.cc: New.
	* testsuite/27_io/basic_filebuf/sputbackc/char/2-io.cc: New.
	* testsuite/27_io/basic_filebuf/sputbackc/char/2-out.cc: New.

From-SVN: r67686