Nathan C.

2003-06-24  Paolo Carlini  <pcarlini@unitus.it>
            Nathan C. Myers  <ncm-nospam@cantrip.org>

	* include/std/std_fstream.h (_M_filepos): Remove.
	(_M_reading, _M_writing): New, encode the various I/O modes:
	'read', 'write' and 'uncommitted'.
	(sync): If there is something to flush, do it, then go to
	'uncommitted' mode.
	* include/bits/fstream.tcc (_M_set_buffer): Overhaul to deal
	with three different cases: __off > 0 (upon underflow),
	__off == 0 (upon overflow), __off == -1 (upon open, setbuf,
	seekoff/pos).
	(_M_underflow): Don't call overflow, set _M_reading to true
	on success, tweak.
	(pbackfail): Set _M_reading to true on pback creation, tweak.
	(overflow): Don't seek, deal with overflow in 'uncommitted' mode,
	set _M_writing to true on success, tweak.
	(seekoff): Simplify, set _M_reading, _M_writing to false, call
	_M_set_buffer(-1) ('uncommitted').
	(open, close, setbuf): Set _M_reading, _M_writing to false and
	call _M_set_buffer(-1), tweak.
	(basic_filebuf): Don't set _M_buf_unified.
	(_M_destroy_internal_buffer): Don't call setg and setp.
	* include/ext/stdio_filebuf.h (stdio_filebuf): Use _M_reading,
	_M_writing and _M_set_buffer(-1).
	* include/std/std_streambuf.h (_M_move_out_cur, _M_move_in_cur,
	_M_out_lim, _M_buf_unified): Remove.
	(basic_streambuf): Don't set _M_out_lim and _M_buf_unified.
	(setp): Don't set _M_out_lim.
	* testsuite/27_io/basic_filebuf/sbumpc/char/1-io.cc: Fix for
	the new logic ('read', 'write' and 'uncommitted' modes): e.g.,
	upon open the mode is 'uncommitted' and therefore the put area
	pointers are null.
	* testsuite/27_io/basic_filebuf/sbumpc/char/1-out.cc: Ditto.
	* testsuite/27_io/basic_filebuf/seekoff/char/3-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/seekpos/char/3-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/setbuf/char/1.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sgetc/char/1-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sgetc/char/1-out.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sgetn/char/1-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sgetn/char/1-out.cc: Ditto.
	* testsuite/27_io/basic_filebuf/snextc/char/1-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/snextc/char/1-out.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sputbackc/char/1-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sputbackc/char/1-out.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sputc/char/1-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sputc/char/1-out.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sputc/char/9701-2.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sputn/char/1-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sputn/char/1-out.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sputn/char/9701-1.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc: Ditto.
	* testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc: Ditto.

	* include/bits/fstream.tcc (showmanyc): Use only the
	documented derivation interface to basic_streambuf (gptr(),
	setg(), etc.) to work right with user specializations.
	* include/bits/streambuf.tcc (sbumpc, sputbackc, sungetc,
	sputc, xsgetn, xsputn, __copy_streambufs): Likewise.
	* include/std/std_streambuf.h (in_avail, sgetc, uflow, stossc):
	Likewise.
	* include/std/std_fstream.h (_M_create_pback, _M_destroy_pback,
	xsgetn): Likewise.

Co-Authored-By: Nathan C. Myers <ncm-nospam@cantrip.org>

From-SVN: r68420

27 files changed, 264 insertions, 253 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 3f7f5d8df9c..bf9cd5cb2ba 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,67 @@
+2003-06-24  Paolo Carlini  <pcarlini@unitus.it>
+            Nathan C. Myers  <ncm-nospam@cantrip.org>
+
+	* include/std/std_fstream.h (_M_filepos): Remove.
+	(_M_reading, _M_writing): New, encode the various I/O modes:
+	'read', 'write' and 'uncommitted'.
+	(sync): If there is something to flush, do it, then go to
+	'uncommitted' mode.
+	* include/bits/fstream.tcc (_M_set_buffer): Overhaul to deal
+	with three different cases: __off > 0 (upon underflow),
+	__off == 0 (upon overflow), __off == -1 (upon open, setbuf,
+	seekoff/pos).
+	(_M_underflow): Don't call overflow, set _M_reading to true
+	on success, tweak.
+	(pbackfail): Set _M_reading to true on pback creation, tweak.
+	(overflow): Don't seek, deal with overflow in 'uncommitted' mode,
+	set _M_writing to true on success, tweak.
+	(seekoff): Simplify, set _M_reading, _M_writing to false, call
+	_M_set_buffer(-1) ('uncommitted').
+	(open, close, setbuf): Set _M_reading, _M_writing to false and
+	call _M_set_buffer(-1), tweak.
+	(basic_filebuf): Don't set _M_buf_unified.
+	(_M_destroy_internal_buffer): Don't call setg and setp.
+	* include/ext/stdio_filebuf.h (stdio_filebuf): Use _M_reading,
+	_M_writing and _M_set_buffer(-1).
+	* include/std/std_streambuf.h (_M_move_out_cur, _M_move_in_cur,
+	_M_out_lim, _M_buf_unified): Remove.
+	(basic_streambuf): Don't set _M_out_lim and _M_buf_unified.
+	(setp): Don't set _M_out_lim.	
+	* testsuite/27_io/basic_filebuf/sbumpc/char/1-io.cc: Fix for
+	the new logic ('read', 'write' and 'uncommitted' modes): e.g.,
+	upon open the mode is 'uncommitted' and therefore the put area
+	pointers are null.
+	* testsuite/27_io/basic_filebuf/sbumpc/char/1-out.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/seekoff/char/3-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/seekpos/char/3-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/setbuf/char/1.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sgetc/char/1-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sgetc/char/1-out.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sgetn/char/1-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sgetn/char/1-out.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/snextc/char/1-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/snextc/char/1-out.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sputbackc/char/1-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sputbackc/char/1-out.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sputc/char/1-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sputc/char/1-out.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sputc/char/9701-2.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sputn/char/1-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sputn/char/1-out.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sputn/char/9701-1.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc: Ditto.
+	* testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc: Ditto.
+
+	* include/bits/fstream.tcc (showmanyc): Use only the
+	documented derivation interface to basic_streambuf (gptr(),
+	setg(), etc.) to work right with user specializations.
+	* include/bits/streambuf.tcc (sbumpc, sputbackc, sungetc,
+	sputc, xsgetn, xsputn, __copy_streambufs): Likewise.
+	* include/std/std_streambuf.h (in_avail, sgetc, uflow, stossc):
+	Likewise.
+	* include/std/std_fstream.h (_M_create_pback, _M_destroy_pback,
+	xsgetn): Likewise.
+
 2003-06-23  Loren J. Rittle  <ljrittle@acm.org>
 
 	* configure.host (freebsd*): Set abi_baseline_pair.
diff --git a/libstdc++-v3/include/bits/fstream.tcc b/libstdc++-v3/include/bits/fstream.tcc
index 13275882c47..22a24dcee69 100644
--- a/libstdc++-v3/include/bits/fstream.tcc
+++ b/libstdc++-v3/include/bits/fstream.tcc
@@ -63,8 +63,6 @@ namespace std
 	  delete [] this->_M_buf;
 	  this->_M_buf = NULL;
 	  _M_buf_allocated = false;
-	  this->setg(NULL, NULL, NULL);
-	  this->setp(NULL, NULL);
 	}
     }
 
@@ -73,10 +71,10 @@ namespace std
     basic_filebuf() : __streambuf_type(), _M_file(&_M_lock), 
     _M_state_cur(__state_type()), _M_state_beg(__state_type()),
     _M_buf(NULL), _M_buf_size(BUFSIZ), _M_buf_allocated(false),
-    _M_last_overflowed(false), _M_filepos(0), _M_pback_cur_save(0), 
-    _M_pback_end_save(0), _M_pback_init(false), _M_codecvt(0)
+    _M_reading(false), _M_writing(false), _M_last_overflowed(false),
+    _M_pback_cur_save(0), _M_pback_end_save(0), _M_pback_init(false),
+    _M_codecvt(0)
     { 
-      this->_M_buf_unified = true; 	  
       if (has_facet<__codecvt_type>(this->_M_buf_locale))
 	_M_codecvt = &use_facet<__codecvt_type>(this->_M_buf_locale);
     }
@@ -95,8 +93,10 @@ namespace std
 	      _M_allocate_internal_buffer();
 	      this->_M_mode = __mode;
 
-	      // Setup initial position of buffer.
-	      _M_set_buffer(0);
+	      // Setup initial buffer to 'uncommitted' mode.
+	      _M_reading = false;
+	      _M_writing = false;
+	      _M_set_buffer(-1);
 
 	      if ((__mode & ios_base::ate) 
 		  && this->seekoff(0, ios_base::end, __mode) < 0)
@@ -120,9 +120,7 @@ namespace std
 	  bool __testfail = false;
 	  try
 	    {
-	      const bool __testput = this->_M_out_beg < this->_M_out_lim;
-
-	      if (__testput 
+	      if (this->pbase() < this->pptr()
 		  && traits_type::eq_int_type(this->overflow(),
 					      traits_type::eof()))
 		__testfail = true;
@@ -144,6 +142,9 @@ namespace std
 	  this->_M_mode = ios_base::openmode(0);
 	  this->_M_pback_init = false;
 	  _M_destroy_internal_buffer();
+	  _M_reading = false;
+	  _M_writing = false;
+	  _M_set_buffer(-1);
 	  
 	  if (!_M_file.close())
 	    __testfail = true;
@@ -167,7 +168,7 @@ namespace std
 	{
 	  // For a stateful encoding (-1) the pending sequence might be just
 	  // shift and unshift prefixes with no actual character.
-	  __ret = this->_M_in_end - this->_M_in_cur;
+	  __ret = this->egptr() - this->gptr();
 	  if (__check_facet(_M_codecvt).encoding() >= 0)
 	    __ret += _M_file.showmanyc() / _M_codecvt->max_length();
 	}
@@ -185,26 +186,21 @@ namespace std
       const bool __testin = this->_M_mode & ios_base::in;
       const bool __testout = this->_M_mode & ios_base::out;
 
-      if (__testin)
+      if (__testin && !_M_writing)
 	{
 	  // Check for pback madness, and if so swich back to the
 	  // normal buffers and jet outta here before expensive
 	  // fileops happen...
 	  _M_destroy_pback();
 
-	  if (this->_M_in_cur < this->_M_in_end)
+	  if (this->gptr() < this->egptr())
 	    {
-	      __ret = traits_type::to_int_type(*this->_M_in_cur);
+	      __ret = traits_type::to_int_type(*this->gptr());
 	      if (__bump)
-		_M_move_in_cur(1);
+		this->gbump(1);
 	      return __ret;
 	    }
 
-	  // Sync internal and external buffers.
-	  if (__testout && this->_M_out_beg < this->_M_out_lim
-	      && traits_type::eq_int_type(this->overflow(), __ret))
-	    return __ret;
-	  
 	  // Get and convert input sequence.
 	  const size_t __buflen = this->_M_buf_size > 1
 	                          ? this->_M_buf_size - 1 : 1;
@@ -212,7 +208,7 @@ namespace std
 	  streamsize __ilen = 0;
 	  if (__check_facet(_M_codecvt).always_noconv())
 	    {
-	      __elen = _M_file.xsgetn(reinterpret_cast<char*>(this->_M_in_beg), __buflen);
+	      __elen = _M_file.xsgetn(reinterpret_cast<char*>(this->eback()), __buflen);
 	      __ilen = __elen;
 	    }
 	  else
@@ -224,13 +220,13 @@ namespace std
 	      char_type* __iend;
 	      codecvt_base::result __r;
 	      __r = _M_codecvt->in(_M_state_cur, __buf, __buf + __elen, 
-				   __eend, this->_M_in_beg, 
-				   this->_M_in_beg + __buflen, __iend);
+				   __eend, this->eback(), 
+				   this->eback() + __buflen, __iend);
 	      if (__r == codecvt_base::ok)
-		__ilen = __iend - this->_M_in_beg;
+		__ilen = __iend - this->eback();
 	      else if (__r == codecvt_base::noconv)
 		{
-		  traits_type::copy(this->_M_in_beg,
+		  traits_type::copy(this->eback(),
 				    reinterpret_cast<char_type*>(__buf), 
 				    __elen);
 		  __ilen = __elen;
@@ -246,9 +242,10 @@ namespace std
 	  if (__ilen > 0)
 	    {
 	      _M_set_buffer(__ilen);
-	      __ret = traits_type::to_int_type(*this->_M_in_cur);
+	      _M_reading = true;
+	      __ret = traits_type::to_int_type(*this->gptr());
 	      if (__bump)
-		_M_move_in_cur(1);
+		this->gbump(1);
 	    }	   	    
 	}
       _M_last_overflowed = false;	
@@ -263,7 +260,7 @@ namespace std
       int_type __ret = traits_type::eof();
       const bool __testin = this->_M_mode & ios_base::in;
 
-      if (__testin)
+      if (__testin && !_M_writing)
 	{
 	  // Remember whether the pback buffer is active, otherwise below
 	  // we may try to store in it a second char (libstdc++/9761).
@@ -271,10 +268,10 @@ namespace std
 	  const bool __testeof = traits_type::eq_int_type(__i, __ret);
 	  
 	  int_type __tmp;
-	  if (this->_M_in_beg < this->_M_in_cur)
+	  if (this->eback() < this->gptr())
 	    {
-	      _M_move_in_cur(-1);
-	      __tmp = traits_type::to_int_type(*this->_M_in_cur);
+	      this->gbump(-1);
+	      __tmp = traits_type::to_int_type(*this->gptr());
 	    }
 	  else if (this->seekoff(-1, ios_base::cur) >= 0)
 	    {
@@ -301,7 +298,8 @@ namespace std
 	  else if (!__testpb)
 	    {
 	      _M_create_pback();
-	      *this->_M_in_cur = traits_type::to_char_type(__i); 
+	      _M_reading = true;
+	      *this->gptr() = traits_type::to_char_type(__i); 
 	      __ret = __i;
 	    }
 	}
@@ -318,37 +316,50 @@ namespace std
       const bool __testeof = traits_type::eq_int_type(__c, __ret);
       const bool __testout = this->_M_mode & ios_base::out;
       
-      if (__testout)
+      if (__testout && !_M_reading)
 	{
-	  if (this->_M_out_beg < this->_M_out_lim)
+	  if (this->pbase() < this->pptr())
 	    {
-	      // Need to restore current position. The position of the
-	      // external byte sequence (_M_file) corresponds to
-	      // _M_filepos, and we need to move it to _M_out_beg for
-	      // the write.
-	      if (_M_filepos != this->_M_out_beg)
-		_M_file.seekoff(this->_M_out_beg - _M_filepos, ios_base::cur);
-
 	      // If appropriate, append the overflow char.
 	      if (!__testeof)
-		*this->_M_out_lim++ = traits_type::to_char_type(__c);
+		{
+		  *this->pptr() = traits_type::to_char_type(__c);
+		  this->pbump(1);
+		}
 	      
 	      // Convert pending sequence to external representation,
 	      // output.
-	      if (_M_convert_to_external(this->_M_out_beg,
-					 this->_M_out_lim - this->_M_out_beg)
+	      if (_M_convert_to_external(this->pbase(),
+					 this->pptr() - this->pbase())
 		  && (!__testeof || (__testeof && !_M_file.sync())))
 		{
 		  _M_set_buffer(0);
 		  __ret = traits_type::not_eof(__c);
 		}
 	    }
+	  else if (this->_M_buf_size > 1)
+	    {
+	      // Overflow in 'uncommitted' mode: set _M_writing, set
+	      // the buffer to the initial 'write' mode, and put __c
+	      // into the buffer.
+	      _M_set_buffer(0);
+	      _M_writing = true;
+	      if (!__testeof)
+		{
+		  *this->pptr() = traits_type::to_char_type(__c);
+		  this->pbump(1);
+		}
+	      __ret = traits_type::not_eof(__c);
+	    }
 	  else
 	    {
 	      // Unbuffered.
 	      char_type __conv = traits_type::to_char_type(__c);
 	      if (__testeof || _M_convert_to_external(&__conv, 1))
-		__ret = traits_type::not_eof(__c);
+		{		  
+		  _M_writing = true;
+		  __ret = traits_type::not_eof(__c);
+		}
 	    }
 	}
       _M_last_overflowed = true;	
@@ -393,7 +404,7 @@ namespace std
 	    }
 	  else
 	    {
-	      // Result == error .
+	      // Result == error.
 	      __blen = 0;
 	    }
 	  
@@ -407,7 +418,7 @@ namespace std
 	  if (__r == codecvt_base::partial)
 	    {
 	      const char_type* __iresume = __iend;
-	      streamsize __rlen = this->_M_out_lim - __iend;
+	      streamsize __rlen = this->pptr() - __iend;
 	      __r = _M_codecvt->out(_M_state_cur, __iresume,
 				    __iresume + __rlen, __iend, __buf, 
 				    __buf + __blen, __bend);
@@ -446,7 +457,9 @@ namespace std
 	  // Step 2: Use the external array.
 	  this->_M_buf = __s;
 	  this->_M_buf_size = __n;
-	  _M_set_buffer(0);
+	  _M_reading = false;
+	  _M_writing = false;
+	  _M_set_buffer(-1);
 	}
       _M_last_overflowed = false;	
       return this; 
@@ -473,41 +486,26 @@ namespace std
 	  // Ditch any pback buffers to avoid confusion.
 	  _M_destroy_pback();
 
-	  if (__way != ios_base::cur || __off != 0)
-	    { 
-	      // Sync the internal and external streams.	      
-	      const bool __testget = this->_M_in_beg < this->_M_in_end;
-	      const bool __testput = this->_M_out_beg < this->_M_out_lim;
-	      off_type __computed_off = __width * __off;
-
-	      if (__testput || _M_last_overflowed)
-		{
-		  // Part one: update the output sequence.
-		  this->sync();
-
-		  // Part two: output unshift sequence.
-		  _M_output_unshift();
-		}
-	      else if (__testget && __way == ios_base::cur)
-		__computed_off += this->_M_in_cur - _M_filepos;
-
-	      // Return pos_type(off_type(-1)) in case of failure.
-	      __ret = _M_file.seekoff(__computed_off, __way, __mode);
-	      _M_set_buffer(0);
-	    }
-	  else
+	  // Sync the internal and external streams.	      
+	  off_type __computed_off = __width * __off;
+	  
+	  if (this->pbase() < this->pptr()
+	      || _M_last_overflowed)
 	    {
-	      // NB: Need to do this in case _M_file in indeterminate
-	      // state, ie _M_file._offset == -1
-	      pos_type __tmp = _M_file.seekoff(__off, ios_base::cur, __mode);
-	      if (__tmp >= 0)
-		{
-		  // Seek successful.
-		  __ret = __tmp;
-		  __ret += std::max(this->_M_out_cur, this->_M_in_cur) 
-		           - _M_filepos;
-		}
+	      // Part one: update the output sequence.
+	      this->sync();
+	      
+	      // Part two: output unshift sequence.
+	      _M_output_unshift();
 	    }
+	  else if (_M_reading && __way == ios_base::cur)
+	    __computed_off += this->gptr() - this->egptr();
+	  
+	  // Return pos_type(off_type(-1)) in case of failure.
+	  __ret = _M_file.seekoff(__computed_off, __way, __mode);
+	  _M_reading = false;
+	  _M_writing = false;
+	  _M_set_buffer(-1);
 	}
       _M_last_overflowed = false;	
       return __ret;
diff --git a/libstdc++-v3/include/bits/streambuf.tcc b/libstdc++-v3/include/bits/streambuf.tcc
index f6a96e85581..d78d8ea45d9 100644
--- a/libstdc++-v3/include/bits/streambuf.tcc
+++ b/libstdc++-v3/include/bits/streambuf.tcc
@@ -45,10 +45,10 @@ namespace std
     sbumpc()
     {
       int_type __ret;
-      if (_M_in_cur < _M_in_end)
+      if (this->gptr() < this->egptr())
 	{
-	  __ret = traits_type::to_int_type(*this->_M_in_cur);
-	  _M_move_in_cur(1);
+	  __ret = traits_type::to_int_type(*this->gptr());
+	  this->gbump(1);
 	}
       else 
 	__ret = this->uflow();
@@ -61,13 +61,13 @@ namespace std
     sputbackc(char_type __c) 
     {
       int_type __ret;
-      const bool __testpos = _M_in_beg < _M_in_cur;
-      if (!__testpos || !traits_type::eq(__c, this->_M_in_cur[-1]))
+      const bool __testpos = this->eback() < this->gptr();
+      if (!__testpos || !traits_type::eq(__c, this->gptr()[-1]))
 	__ret = this->pbackfail(traits_type::to_int_type(__c));
       else 
 	{
-	  _M_move_in_cur(-1);
-	  __ret = traits_type::to_int_type(*this->_M_in_cur);
+	  this->gbump(-1);
+	  __ret = traits_type::to_int_type(*this->gptr());
 	}
       return __ret;
     }
@@ -78,10 +78,10 @@ namespace std
     sungetc()
     {
       int_type __ret;
-      if (_M_in_beg < _M_in_cur)
+      if (this->eback() < this->gptr())
 	{
-	  _M_move_in_cur(-1);
-	  __ret = traits_type::to_int_type(*_M_in_cur);
+	  this->gbump(-1);
+	  __ret = traits_type::to_int_type(*this->gptr());
 	}
       else 
 	__ret = this->pbackfail();
@@ -94,10 +94,10 @@ namespace std
     sputc(char_type __c)
     {
       int_type __ret;
-      if (_M_out_cur < _M_out_end)
+      if (this->pptr() < this->epptr())
 	{
-	  *_M_out_cur = __c;
-	  _M_move_out_cur(1);
+	  *this->pptr() = __c;
+	  this->pbump(1);
 	  __ret = traits_type::to_int_type(__c);
 	}
       else
@@ -113,15 +113,15 @@ namespace std
       streamsize __ret = 0;
       while (__ret < __n)
 	{
-	  const size_t __buf_len = _M_in_end - _M_in_cur;
+	  const size_t __buf_len = this->egptr() - this->gptr();
 	  if (__buf_len)
 	    {
 	      const size_t __remaining = __n - __ret;
 	      const size_t __len = std::min(__buf_len, __remaining);
-	      traits_type::copy(__s, _M_in_cur, __len);
+	      traits_type::copy(__s, this->gptr(), __len);
 	      __ret += __len;
 	      __s += __len;
-	      _M_move_in_cur(__len);
+	      this->gbump(__len);
 	    }
 	  
 	  if (__ret < __n)
@@ -147,15 +147,15 @@ namespace std
       streamsize __ret = 0;
       while (__ret < __n)
 	{
-	  const size_t __buf_len = _M_out_end - _M_out_cur;
+	  const size_t __buf_len = this->epptr() - this->pptr();
 	  if (__buf_len)
 	    {
 	      const size_t __remaining = __n - __ret;
 	      const size_t __len = std::min(__buf_len, __remaining);
-	      traits_type::copy(_M_out_cur, __s, __len);
+	      traits_type::copy(this->pptr(), __s, __len);
 	      __ret += __len;
 	      __s += __len;
-	      _M_move_out_cur(__len);
+	      this->pbump(__len);
 	    }
 
 	  if (__ret < __n)
@@ -189,12 +189,12 @@ namespace std
 	  typename _Traits::int_type __c = __sbin->sgetc();
 	  while (!_Traits::eq_int_type(__c, _Traits::eof()))
 	    {
-	      const size_t __n = __sbin->_M_in_end - __sbin->_M_in_cur;
+	      const size_t __n = __sbin->egptr() - __sbin->gptr();
 	      if (__n > 1)
 		{
-		  const size_t __wrote = __sbout->sputn(__sbin->_M_in_cur,
+		  const size_t __wrote = __sbout->sputn(__sbin->gptr(),
 							__n);
-		  __sbin->_M_move_in_cur(__wrote);
+		  __sbin->gbump(__wrote);
 		  __ret += __wrote;
 		  if (__wrote < __n)
 		    break;
diff --git a/libstdc++-v3/include/ext/stdio_filebuf.h b/libstdc++-v3/include/ext/stdio_filebuf.h
index 43ef34dec72..574a62b8160 100644
--- a/libstdc++-v3/include/ext/stdio_filebuf.h
+++ b/libstdc++-v3/include/ext/stdio_filebuf.h
@@ -127,7 +127,9 @@ namespace __gnu_cxx
 	  this->_M_mode = __mode;
 	  this->_M_buf_size = __size;
 	  _M_allocate_internal_buffer();
-	  _M_set_buffer(0);
+	  this->_M_reading = false;
+	  this->_M_writing = false;
+	  _M_set_buffer(-1);
 	}
     }
 
@@ -142,7 +144,9 @@ namespace __gnu_cxx
 	  this->_M_mode = __mode;
 	  this->_M_buf_size = __size;
 	  _M_allocate_internal_buffer();
-	  _M_set_buffer(0);
+	  this->_M_reading = false;
+	  this->_M_writing = false;
+	  _M_set_buffer(-1);
 	}
     }
 } // namespace __gnu_cxx
diff --git a/libstdc++-v3/include/std/std_fstream.h b/libstdc++-v3/include/std/std_fstream.h
index 7cc0dbd8e1f..605fad22b3e 100644
--- a/libstdc++-v3/include/std/std_fstream.h
+++ b/libstdc++-v3/include/std/std_fstream.h
@@ -137,19 +137,18 @@ namespace std
        *  @endif
       */
       bool			_M_buf_allocated;
-      
+
+      // _M_reading == false && _M_writing == false for 'uncommitted' mode;  
+      // _M_reading == true for 'read' mode;
+      // _M_writing == true for 'write' mode;
+      //
+      // NB: _M_reading == true && _M_writing == true is unused.
+      bool                      _M_reading;
+      bool                      _M_writing;
+
       // XXX Needed?
       bool			_M_last_overflowed;
 
-      // The position in the buffer corresponding to the external file
-      // pointer.
-      /**
-       *  @if maint
-       *  @doctodo
-       *  @endif
-      */
-      char_type*		_M_filepos;
-
       //@{
       /**
        *  @if maint
@@ -175,8 +174,8 @@ namespace std
       {
 	if (!_M_pback_init)
 	  {
-	    _M_pback_cur_save = this->_M_in_cur;
-	    _M_pback_end_save = this->_M_in_end;
+	    _M_pback_cur_save = this->gptr();
+	    _M_pback_end_save = this->egptr();
 	    this->setg(&_M_pback, &_M_pback, &_M_pback + 1);
 	    _M_pback_init = true;
 	  }
@@ -191,7 +190,7 @@ namespace std
 	if (_M_pback_init)
 	  {
 	    // Length _M_in_cur moved in the pback buffer.
-	    _M_pback_cur_save += this->_M_in_cur != this->_M_in_beg;
+	    _M_pback_cur_save += this->gptr() != this->eback();
 	    this->setg(this->_M_buf, _M_pback_cur_save, _M_pback_end_save);
 	    _M_pback_init = false;
 	  }
@@ -365,23 +364,23 @@ namespace std
       sync()
       {
 	int __ret = 0;
-	const bool __testput = this->_M_out_beg < this->_M_out_lim;
 
 	// Make sure that the internal buffer resyncs its idea of
 	// the file position with the external file.
-	if (__testput)
+	// NB: _M_file.sync() will be called within.
+	if (this->pbase() < this->pptr())
 	  {
-	    // Need to restore current position after the write.
-	    const off_type __off = this->_M_out_cur - this->_M_out_lim;
-
-	    // _M_file.sync() will be called within.
-	    if (traits_type::eq_int_type(this->overflow(), traits_type::eof()))
+	    int_type __tmp = this->overflow();
+	    if (traits_type::eq_int_type(__tmp, traits_type::eof()))
 	      __ret = -1;
-	    else if (__off)
-	      _M_file.seekoff(__off, ios_base::cur);
+	    else
+	      {
+		_M_set_buffer(-1);
+		_M_reading = false;
+		_M_writing = false;
+	      }
 	  }
-	else
-	  _M_file.sync();
+
 	_M_last_overflowed = false;
 	return __ret;
       }
@@ -398,9 +397,10 @@ namespace std
 	streamsize __ret = 0;
 	if (this->_M_pback_init)
 	  {
-	    if (__n && this->_M_in_cur == this->_M_in_beg)
+	    if (__n && this->gptr() == this->eback())
 	      {
-		*__s++ = *this->_M_in_cur++;
+		*__s++ = *this->gptr();
+		this->gbump(1);
 		__ret = 1;
 	      }
 	    _M_destroy_pback();
@@ -427,10 +427,13 @@ namespace std
       _M_output_unshift();
 
       // This function sets the pointers of the internal buffer, both get
-      // and put areas. Typically, __off == _M_in_end - _M_in_beg upon
-      // _M_underflow; __off == 0 upon overflow, seekoff, open, setbuf.
+      // and put areas. Typically:
+      //
+      //  __off == egptr() - eback() upon underflow/uflow ('read' mode);
+      //  __off == 0 upon overflow ('write' mode);
+      //  __off == -1 upon open, setbuf, seekoff/pos ('uncommitted' mode).
       // 
-      // NB: _M_out_end - _M_out_beg == _M_buf_size - 1, since _M_buf_size
+      // NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size
       // reflects the actual allocated memory and the last cell is reserved
       // for the overflow char of a full put area.
       void
@@ -439,14 +442,15 @@ namespace std
  	const bool __testin = this->_M_mode & ios_base::in;
  	const bool __testout = this->_M_mode & ios_base::out;
 	
-	if (__testin)
+	if (__testin && __off > 0)
 	  this->setg(this->_M_buf, this->_M_buf, this->_M_buf + __off);
-	if (__testout && this->_M_buf_size > 1)
-	  {
-	    this->setp(this->_M_buf, this->_M_buf + this->_M_buf_size - 1);
-	    this->_M_out_lim += __off;
-	  }
-	_M_filepos = this->_M_buf + __off;
+	else
+	  this->setg(this->_M_buf, this->_M_buf, this->_M_buf);
+
+	if (__testout && __off == 0 && this->_M_buf_size > 1 )
+	  this->setp(this->_M_buf, this->_M_buf + this->_M_buf_size - 1);
+	else
+	  this->setp(NULL, NULL);
       }
     };
 
diff --git a/libstdc++-v3/include/std/std_streambuf.h b/libstdc++-v3/include/std/std_streambuf.h
index fa85bf4641e..b69de0313a8 100644
--- a/libstdc++-v3/include/std/std_streambuf.h
+++ b/libstdc++-v3/include/std/std_streambuf.h
@@ -176,25 +176,6 @@ namespace std
       char_type* 		_M_out_cur;    // Current put area. 
       char_type* 		_M_out_end;    // End of put area.
 
-      //@{
-      /**
-       *  @if maint
-       *  setp (and _M_set_buffer(0) in basic_filebuf) set it equal to
-       *  _M_out_beg, then at each put operation it may be moved
-       *  forward (toward _M_out_end) by _M_move_out_cur.
-       *  @endif
-      */      
-      char_type*                _M_out_lim;    // End limit of used put area.
-      //@}
-
-      /**
-       *  @if maint
-       *  True iff _M_in_* and _M_out_* buffers should always point to
-       *  the same place.  True for fstreams, false for sstreams.
-       *  @endif
-      */
-      bool 			_M_buf_unified;	
-
       /**
        *  @if maint
        *  Place to stash in || out || in | out settings for current streambuf.
@@ -216,50 +197,11 @@ namespace std
       */
       fpos<__state_type>	_M_pos;
 
-      // Correctly sets the _M_in_cur pointer, and bumps the
-      // _M_out_cur pointer as well if necessary.
-      void 
-      _M_move_in_cur(off_type __n) // argument needs to be +-
-      {
-	const bool __testout = _M_out_cur;
-	_M_in_cur += __n;
-	if (__testout && _M_buf_unified)
-	  _M_out_cur += __n;
-      }
-
-      // Correctly sets the _M_out_cur pointer, and bumps the
-      // appropriate _M_out_lim and _M_in_end pointers as well. Necessary
-      // for the un-tied stringbufs, in in|out mode.
-      // Invariant:
-      // __n + _M_out_[cur, lim] <= _M_out_end
-      // Assuming all _M_out_[beg, cur, lim] pointers are operating on
-      // the same range:
-      // _M_out_beg <= _M_*_ <= _M_out_end
-      void 
-      _M_move_out_cur(off_type __n) // argument needs to be +-
-      {
-	_M_out_cur += __n;
-	if (__builtin_expect(_M_buf_unified, false))
-	  {
-	    const bool __testin = _M_in_cur;
-	    if (__testin)
-	      _M_in_cur += __n;
-	    if (_M_out_cur > _M_out_lim)
-	      {
-		_M_out_lim = _M_out_cur;
-		// NB: in | out buffers drag the _M_in_end pointer along...
-		if (__testin)
-		  _M_in_end += __n;
-	      }
-	  }
-      }
-
   public:
       /// Destructor deallocates no buffer space.
       virtual 
       ~basic_streambuf() 
       {
-	_M_buf_unified = false;
 	_M_mode = ios_base::openmode(0);
       }
 
@@ -330,7 +272,7 @@ namespace std
       streamsize 
       in_avail() 
       { 
-	const streamsize __ret = _M_in_end - _M_in_cur;
+	const streamsize __ret = this->egptr() - this->gptr();
 	return __ret ? __ret : this->showmanyc();
       }
 
@@ -373,8 +315,8 @@ namespace std
       sgetc()
       {
 	int_type __ret;
-	if (_M_in_cur < _M_in_end)
-	  __ret = traits_type::to_int_type(*this->_M_in_cur);
+	if (this->gptr() < this->egptr())
+	  __ret = traits_type::to_int_type(*this->gptr());
 	else 
 	  __ret = this->underflow();
 	return __ret;
@@ -461,7 +403,6 @@ namespace std
       basic_streambuf()
       : _M_in_beg(0), _M_in_cur(0), _M_in_end(0), 
       _M_out_beg(0), _M_out_cur(0), _M_out_end(0),
-      _M_out_lim(0), _M_buf_unified(false), 
       _M_mode(ios_base::openmode(0)),_M_buf_locale(locale()) 
       { }
 
@@ -553,7 +494,7 @@ namespace std
       void 
       setp(char_type* __pbeg, char_type* __pend)
       { 
-	_M_out_beg = _M_out_cur = _M_out_lim = __pbeg; 
+	_M_out_beg = _M_out_cur = __pbeg; 
 	_M_out_end = __pend;
       }
 
@@ -703,10 +644,10 @@ namespace std
 	int_type __ret = traits_type::eof();
 	const bool __testeof = traits_type::eq_int_type(this->underflow(), 
 							__ret);
-	if (!__testeof && _M_in_cur < _M_in_end)
+	if (!__testeof && this->gptr() < this->egptr())
 	  {
-	    __ret = traits_type::to_int_type(*_M_in_cur);
-	    ++_M_in_cur;
+	    __ret = traits_type::to_int_type(*this->gptr());
+	    this->gbump(1);
 	  }
 	return __ret;    
       }
@@ -786,8 +727,8 @@ namespace std
       void 
       stossc() 
       {
-	if (_M_in_cur < _M_in_end) 
-	  ++_M_in_cur;
+	if (this->gptr() < this->egptr()) 
+	  this->gbump(1);
 	else 
 	  this->uflow();
       }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sbumpc/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sbumpc/char/1-io.cc
index 9098a2083e7..451518c1f23 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sbumpc/char/1-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sbumpc/char/1-io.cc
@@ -46,11 +46,11 @@ void test05()
   {
     constraint_filebuf fb_03; 
     fb_03.open(name_03, ios_base::out | ios_base::in | ios_base::trunc); 
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     int_type c5 = fb_03.sbumpc();
     VERIFY( c5 == traits_type::eof() );
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
   }
 
@@ -58,9 +58,9 @@ void test05()
   {
     constraint_filebuf fb_01; 
     fb_01.open(name_01, ios_base::in | ios_base::out);
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
 
-     int_type c1 = fb_01.sbumpc();
+    int_type c1 = fb_01.sbumpc();
     VERIFY( c1 == '/' );
     int_type c3 = fb_01.sbumpc();
     VERIFY( c3 == '/' );
@@ -80,7 +80,7 @@ void test05()
     VERIFY( c2 == '9' );
     VERIFY( c3 == '0' );
 
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( fb_01.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sbumpc/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sbumpc/char/1-out.cc
index ff0cb97dd5d..69559a9a69c 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sbumpc/char/1-out.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sbumpc/char/1-out.cc
@@ -45,13 +45,13 @@ void test05()
   {
     constraint_filebuf fb_02; 
     fb_02.open(name_02, ios_base::out | ios_base::trunc);
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
     int_type c2 = fb_02.sbumpc();
     VERIFY( c2 == traits_type::eof() );
     int_type c4 = fb_02.sbumpc();
     VERIFY( c4 == traits_type::eof() );
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-io.cc
index 7552d889eb6..d310d513871 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-io.cc
@@ -59,7 +59,7 @@ void test05()
   {
     constraint_filebuf fb_03;
     fb_03.open(name_01, ios_base::out | ios_base::in);
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     // 27filebuf-3.txt = bd23456789:;<=>?...
     //beg
@@ -111,7 +111,7 @@ void test05()
     fb_03.pubsync(); 
     c3 = fb_03.sgetc();
     VERIFY( c1 == c3 );
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( fb_03.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/3-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/3-io.cc
index 097edb76b2a..6efbb9512ae 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/3-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/3-io.cc
@@ -60,7 +60,7 @@ void test05()
   {
     constraint_filebuf fb_03;
     fb_03.open(name_01, ios_base::out | ios_base::in);
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     pt_1 = fb_03.pubseekoff(78, ios_base::beg);
     off_1 = pt_1;
@@ -84,7 +84,7 @@ void test05()
     VERIFY( off_1 > off_2 );
     fb_03.sputn("\nof the wonderful things he does!!\nok", 37);
     fb_03.pubsync();
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     fb_03.close();
     VERIFY( !fb_03.is_open() );
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/setbuf/char/1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/setbuf/char/1.cc
index d4f9e4c15dc..25511d93ea6 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/setbuf/char/1.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/setbuf/char/1.cc
@@ -79,7 +79,7 @@ void test05()
     // setbuf
     // pubsetbuf(char_type* s, streamsize n)
     f_tmp.pubsetbuf(0, 0);
-    VERIFY( !f_tmp.check_pointers() );
+    VERIFY( f_tmp.check_pointers() );
   }
 }
 
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetc/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetc/char/1-io.cc
index 6882234f1d5..7a754768002 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetc/char/1-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetc/char/1-io.cc
@@ -48,13 +48,13 @@ void test05()
   {
     constraint_filebuf fb_03; // in | out
     fb_03.open(name_03, ios::out | ios::in | ios::trunc); 
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     c1 = fb_03.sgetc();
     c2 = fb_03.sbumpc();
     VERIFY( c1 == traits_type::eof() );
     VERIFY( c1 == c2 );
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
   }
 
@@ -62,7 +62,7 @@ void test05()
   {
     constraint_filebuf fb_01; // in 
     fb_01.open(name_01, ios::in | ios::out);
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     c1 = fb_01.sgetc();
     VERIFY( c1 == '/' );
     c2 = fb_01.sgetc();
@@ -74,7 +74,7 @@ void test05()
     VERIFY( c1 == '/' );
     VERIFY( c2 == ' ' );
     VERIFY( c3 == ' ' );
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( fb_01.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetc/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetc/char/1-out.cc
index 30d4d1b5e40..41e18e435e4 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetc/char/1-out.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetc/char/1-out.cc
@@ -47,7 +47,7 @@ void test05()
   {
     constraint_filebuf fb_02; // out
     fb_02.open(name_02, ios::out | ios::trunc);    
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
     c1 = fb_02.sgetc();
     VERIFY( c1 == traits_type::eof() );
@@ -57,7 +57,7 @@ void test05()
     c1 = fb_02.sbumpc();
     c2 = fb_02.sgetc();
     VERIFY( c1 == c2 );
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetn/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetn/char/1-io.cc
index ff2663ef911..e1d9a38f75e 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetn/char/1-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetn/char/1-io.cc
@@ -55,11 +55,11 @@ void test05()
   {
     constraint_filebuf fb_03; 
     fb_03.open(name_03, ios_base::out | ios_base::in | ios_base::trunc); 
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     strmsz_1 = fb_03.sgetn(carray1, 10);
     VERIFY( strmsz_1 == 0 ); 
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
   }
 
@@ -70,7 +70,7 @@ void test05()
     // to trigger the same underflow situation everywhere.
     fb_01.pubsetbuf(buffer, 8192);
     fb_01.open(name_01, ios_base::in | ios_base::out);
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     strmsz_1 = fb_01.in_avail();
     strmsz_2 = fb_01.sgetn(carray1, 10);
     VERIFY( strmsz_2 == 10 );
@@ -87,7 +87,7 @@ void test05()
     VERIFY( strmsz_1 > 0 );
     strmsz_2 = fb_01.sgetn(carray2, strmsz_1 + 5);
     VERIFY( strmsz_1 == strmsz_2 ); //at the end of the actual file 
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( !fb_01.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetn/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetn/char/1-out.cc
index 7bd5e37e440..eb710f2d056 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetn/char/1-out.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sgetn/char/1-out.cc
@@ -53,7 +53,7 @@ void test05()
   {
     constraint_filebuf fb_02;
     fb_02.open(name_02, ios_base::out | ios_base::trunc);
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
     strmsz_2 = fb_02.in_avail();
     strmsz_2 = fb_02.sgetn(carray2, 10);
@@ -66,7 +66,7 @@ void test05()
     VERIFY( strmsz_2 == 0 );
     c4 = fb_02.sgetc(); 
     VERIFY( c4 == traits_type::eof() );
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/snextc/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/snextc/char/1-io.cc
index 0627648cc7b..aa5000d987a 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/snextc/char/1-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/snextc/char/1-io.cc
@@ -48,11 +48,11 @@ void test05()
   {
     constraint_filebuf fb_03; 
     fb_03.open(name_03, ios_base::out | ios_base::in | ios_base::trunc);
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     c3 = fb_03.snextc();
     VERIFY( c3 == traits_type::eof() );
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
  }
 
@@ -60,7 +60,7 @@ void test05()
   {  
     constraint_filebuf fb_01; 
     fb_01.open(name_01, ios_base::in | ios_base::out);
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     int_type c4 = fb_01.sbumpc();
     VERIFY( c4 == '/' );
     c4 = fb_01.sbumpc();
@@ -71,7 +71,7 @@ void test05()
     VERIFY( c1 == '9' );
     c4 = fb_01.sgetc();
     VERIFY( c4 == '9' );
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( fb_01.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/snextc/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/snextc/char/1-out.cc
index d226ac29699..118383a978e 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/snextc/char/1-out.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/snextc/char/1-out.cc
@@ -48,13 +48,13 @@ void test05()
   {    
     constraint_filebuf fb_02;
     fb_02.open(name_02, ios_base::out | ios_base::trunc);
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
     c2 = fb_02.snextc();
     VERIFY( c2 == traits_type::eof() );
     c2 = fb_02.snextc();
     VERIFY( c2 == traits_type::eof() );
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputbackc/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputbackc/char/1-io.cc
index ca300cedbd1..f43191cc730 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputbackc/char/1-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputbackc/char/1-io.cc
@@ -50,7 +50,7 @@ void test01()
   {
     constraint_filebuf fb_01; 
     fb_01.open(name_01, ios_base::out | ios_base::in | ios_base::trunc);
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( !fb_01.read_position() );
     strmsz_1 = fb_01.sputn("racadabras", 10);//"abracadabras or what?"
     strmsz_2 = fb_01.sputn(", i wanna reach out and", 10);
@@ -90,7 +90,7 @@ void test01()
     c3 = fb_01.sgetc();
     VERIFY( c3 == c2 );
     VERIFY( strmsz_1 + 1 == strmsz_2 );
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( fb_01.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputbackc/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputbackc/char/1-out.cc
index 78d3b790df6..83d57e2fc61 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputbackc/char/1-out.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputbackc/char/1-out.cc
@@ -48,7 +48,7 @@ void test01()
   {
     constraint_filebuf fb_01; // out
     fb_01.open(name_01, ios::out | ios::trunc);    
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( !fb_01.read_position() );
     c1 = fb_01.sgetc();
     VERIFY( c1 == traits_type::eof() );
@@ -58,7 +58,7 @@ void test01()
     c1 = fb_01.sbumpc();
     c2 = fb_01.sputbackc('a');
     VERIFY( c1 == c2 );
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( !fb_01.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/1-io.cc
index c1717612b6c..72350c0a8b8 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/1-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/1-io.cc
@@ -52,7 +52,7 @@ void test05()
   {
     constraint_filebuf fb_03; 
     fb_03.open(name_03, ios_base::out | ios_base::in | ios_base::trunc);
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     c1 = fb_03.sputc('b'); 
     VERIFY( c1 == 'b' );
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/1-out.cc
index 987b4e26217..f4b5b73f0e7 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/1-out.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/1-out.cc
@@ -51,7 +51,7 @@ void test05()
   {
     constraint_filebuf fb_02; 
     fb_02.open(name_02, ios_base::out | ios_base::trunc);
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
     c1 = fb_02.sputc('a');
     VERIFY( c1 == 'a' ); 
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/9701-2.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/9701-2.cc
index e0358ef5252..1d100dd3ede 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/9701-2.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputc/char/9701-2.cc
@@ -55,7 +55,7 @@ void test11()
   dfbuf_01.open(name_05, std::ios_base::out);
   over_called = false;
   dfbuf_01.sputc('i');
-  VERIFY( !over_called );
+  VERIFY( over_called );
   over_expected = dfbuf_01.pub_epptr() == dfbuf_01.pub_pptr();
   over_called = false;
   dfbuf_01.sputc('v');
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/1-io.cc
index 37509601427..9ec3d259ca8 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/1-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/1-io.cc
@@ -50,7 +50,7 @@ void test05()
   {
     constraint_filebuf fb_03; 
     fb_03.open(name_03, ios_base::out | ios_base::in | ios_base::trunc);
-    VERIFY( fb_03.write_position() );
+    VERIFY( !fb_03.write_position() );
     VERIFY( !fb_03.read_position() );
     strmsz_1 = fb_03.sputn("racadabras", 10);//"abracadabras or what?"
     VERIFY( strmsz_1 == 10 );
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/1-out.cc
index 647f310d87f..f98bcd745b1 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/1-out.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/1-out.cc
@@ -49,7 +49,7 @@ void test05()
   {
     constraint_filebuf fb_02; 
     fb_02.open(name_02, ios_base::out | ios_base::trunc);
-    VERIFY( fb_02.write_position() );
+    VERIFY( !fb_02.write_position() );
     VERIFY( !fb_02.read_position() );
     strmsz_1 = fb_02.sputn("racadabras", 10);
     VERIFY( strmsz_1 == 10 );  
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/9701-1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/9701-1.cc
index 3c350a4d360..b675d79d0bb 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/9701-1.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sputn/char/9701-1.cc
@@ -59,7 +59,7 @@ void test11()
   dfbuf_02.open(name_05, std::ios_base::out);
   over_called = false;
   dfbuf_02.sputn("sonne's", 7);
-  VERIFY( !over_called );
+  VERIFY( over_called );
   over_expected = dfbuf_02.pub_epptr() == dfbuf_02.pub_pptr();
   over_called = false;
   dfbuf_02.sputn(" peak", 5);
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc
index 38819b6ba19..78464834bec 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc
@@ -50,7 +50,7 @@ void test01()
   {
     constraint_filebuf fb_01; 
     fb_01.open(name_01, ios_base::out | ios_base::in | ios_base::trunc);
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( !fb_01.read_position() );
     fb_01.sputc('u');
     fb_01.sputc('v');
@@ -71,7 +71,7 @@ void test01()
     VERIFY( c1 != c2 );
     VERIFY( strmsz_2 != strmsz_1 );
     VERIFY( strmsz_2 == 1 );
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( fb_01.read_position() );
   }
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc
index f7d78312420..99cf7ed383c 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc
@@ -48,7 +48,7 @@ void test01()
   {
     constraint_filebuf fb_01; // out
     fb_01.open(name_01, ios::out | ios::trunc);    
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( !fb_01.read_position() );
     c1 = fb_01.sgetc();
     VERIFY( c1 == traits_type::eof() );
@@ -58,7 +58,7 @@ void test01()
     c1 = fb_01.sbumpc();
     c2 = fb_01.sungetc();
     VERIFY( c1 == c2 );
-    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.write_position() );
     VERIFY( !fb_01.read_position() );
   }
 }