2003-06-22 Paolo Carlini <pcarlini@unitus.it>

2003-06-22  Paolo Carlini  <pcarlini@unitus.it>
	    Nathan C. Myers  <ncm-nospam@cantrip.org>

	* include/std/std_streambuf.h (_M_move_out_cur): _M_out_lim
	is now used only for filebuf, when _M_buf_unified is true.
	epgtr() plays the role of _M_out_lim but it's only updated
	upon overflow, underflow, uflow, seekoff/pos.
	* include/bits/sstream.tcc (_M_underflow): New, implements
	stringbuf::underflow and uflow.
	(seekoff, seekpos): Tweak, use  _M_update_egptr.
	* include/std/std_sstream.h (str): Rewrote, deal correctly
	with the new logic, in particular, when pptr() > egptr().
	(_M_sync): When __testout && !__testin set all the get area
	pointers to the current string end.
	(_M_update_egptr): New, internal function updating egptr()
	to the actual string end.
	(_M_underflow): New, declare.
	(underflow): Dispatch to _M_underflow(false).
	(uflow): Dispatch to _M_underflow(true).

	* include/bits/sstream.tcc (pbackfail, overflow, seekoff,
	seekpos): Use only the documented derivation interface to
	basic_streambuf (gptr(), setg(), etc.) to work right with
	user specializations.
	* include/std/std_sstream.h (str, _M_sync): Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@68347 138bc75d-0d04-0410-961f-82ee72b054a4