2004-10-03 Paolo Carlini <pcarlini@suse.de>

        Merged to mainline at tag libstdcxx_so_7-merge-20041003.


git-svn-id: https://gcc.gnu.org/svn/gcc/branches/libstdcxx_so_7-branch@88456 138bc75d-0d04-0410-961f-82ee72b054a4

25 files changed, 323 insertions, 387 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 560c5327ac4..bbf654d0f00 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,105 @@
+2004-10-03  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/bits/stl_list.h: Trivial formatting fixes.
+	* include/bits/stl_tree.h: Likewise.
+
+2004-10-03  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/bits/sstream.tcc (seekpos): In case of success, just
+	return __sp.
+
+2004-10-01  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/bits/sstream.tcc (pbackfail): Implement correctly
+	27.7.1.3/2, bullet 2: if mode & ios_base::out is false do not
+	write in the buffer.
+	* testsuite/27_io/basic_stringbuf/pbackfail/char/1.cc: New.
+	* testsuite/27_io/basic_stringbuf/pbackfail/char/2.cc: Likewise.
+	* testsuite/27_io/basic_stringbuf/pbackfail/wchar_t/1.cc: Likewise.
+	* testsuite/27_io/basic_stringbuf/pbackfail/wchar_t/2.cc: Likewise.
+	* testsuite/27_io/basic_istream/putback/char/1.cc: Tweak consistently.
+
+2004-10-01  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/bits/sstream.tcc (seekpos): Minor rearrangement of two
+	conditionals consistently with seekoff.
+	* include/std/std_sstream.h (setbuf): Avoid a string temporary.
+	(_M_sync): Simplify a bit, clean-up comment.
+
+2004-09-30  Paolo Carlini  <pcarlini@suse.de>
+
+	PR libstdc++/10975 (DR 453)
+	* include/bits/sstream.tcc (seekoff): Don't fail if __beg == 0
+	and __off == 0.
+	* docs/html/ext/howto.html: Add an entry for DR 453.
+	* testsuite/27_io/basic_stringbuf/seekoff/char/10975.cc: New.
+	* testsuite/27_io/basic_stringbuf/seekoff/wchar_t/10975.cc: Likewise.
+	* testsuite/27_io/basic_istream/tellg/char/1.cc: Tweak consistently.
+	* testsuite/27_io/basic_ostream/tellp/char/1.cc: Likewise.
+	* testsuite/27_io/basic_ostream/tellp/char/2.cc: Likewise.
+	* testsuite/27_io/basic_istream/seekg/char/2346-fstream.cc: Fix and
+	move to...
+	* testsuite/27_io/basic_istream/seekp/char/2346-fstream.cc: ... here.
+	* testsuite/27_io/basic_istream/seekg/char/2346-sstream.cc: Fix and
+	move to...
+	* testsuite/27_io/basic_istream/seekp/char/2346-sstream.cc: ... here.
+
+2004-09-29  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/std/std_sstream.h (basic_stringbuf(ios_base::openmode)):
+	Don't use _M_stringbuf_init, keep the pointers null, per 27.7.1.1.
+	(str()): Slightly tweak, protect from pptr() == 0.
+	(_M_update_egptr()): Likewise.
+	* include/bits/sstream.tcc (ssekoff, seekpos): In order to check
+	for an empty buffer use __beg instead of _M_string.capacity().
+	* testsuite/27_io/basic_stringbuf/cons/char/1.cc: New.
+	* testsuite/27_io/basic_stringbuf/cons/wchar_t/1.cc: Likewise.
+
+	* testsuite/27_io/basic_filebuf/cons/char/1.cc: New.
+	* testsuite/27_io/basic_filebuf/cons/wchar_t/1.cc: Likewise.
+	* testsuite/27_io/basic_streambuf/cons/char/1.cc: Update.
+	* testsuite/27_io/basic_streambuf/cons/wchar_t/1.cc: Likewise.
+
+2004-09-29  Paolo Carlini  <pcarlini@suse.de>
+	    Benjamin Kosnik  <bkoz@redhat.com>
+	
+	* testsuite/testsuite_io.h (class constraint_buf): New, extended
+	and templatized version of constraint_filebuf; add typedefs for
+	streambuf/stringbuf/filebuf and wchar_t counterparts.
+
+2004-09-28  Paolo Carlini  <pcarlini@suse.de>
+
+	PR libstdc++/16612
+	* include/bits/basic_string.h (_M_dispose, _M_refcopy,
+	basic_string()): When _GLIBCXX_FULLY_DYNAMIC_STRING is defined,
+	don't deal with _S_empty_rep.
+	* include/bits/basic_string.tcc (_S_construct, _M_destroy,
+	_M_leak_hard, _M_mutate): Likewise.
+	* acinclude.m4 (GLIBCXX_ENABLE_FULLY_DYNAMIC_STRING): New.
+	* acconfig.h: Add corresponding undef. 	
+	* configure.ac: Use GLIBCXX_ENABLE_FULLY_DYNAMIC_STRING.
+	* docs/html/configopts.html: Document --enable-fully-dynamic-string.
+	* configure: Regenerate.
+	* config.h.in: Likewise.
+
+2004-09-28  Benjamin Kosnik  <bkoz@redhat.com>
+            Paolo Carlini  <pcarlini@suse.de>
+
+	* testsuite/21_strings/basic_string/operations/char/1.cc: New.
+	* testsuite/21_strings/basic_string/operations/wchar_t/1.cc: New.
+	* testsuite/21_strings/basic_string/element_access/char/empty.cc: New.
+	* testsuite/21_strings/basic_string/element_access/wchar_t/empty.cc: 
+	New.
+
+2004-09-28  Paolo Carlini  <pcarlini@suse.de>
+
+	* README: Remove obsolete entry about include/c_shadow.
+
+2004-09-24  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR libstdc++/17469
+	* testsuite/lib/libstdc++.exp: Don't use global ld_library_path.
+
 2004-09-24  Paolo Carlini  <pcarlini@suse.de>
 
 	* src/localename.cc (locale::locale(const char*)): Minor tweaks:
diff --git a/libstdc++-v3/ChangeLog.libstdcxx_so_7-branch b/libstdc++-v3/ChangeLog.libstdcxx_so_7-branch
index 85bd8054890..06e8cf2e988 100644
--- a/libstdc++-v3/ChangeLog.libstdcxx_so_7-branch
+++ b/libstdc++-v3/ChangeLog.libstdcxx_so_7-branch
@@ -1,3 +1,7 @@
+2004-10-03  Paolo Carlini  <pcarlini@suse.de>
+
+        Merged to mainline at tag libstdcxx_so_7-merge-20041003.
+
 2004-09-24  Paolo Carlini  <pcarlini@suse.de>
 
         Merged to mainline at tag libstdcxx_so_7-merge-20040924.
diff --git a/libstdc++-v3/README b/libstdc++-v3/README
index 6844909a1cf..1064095fba7 100644
--- a/libstdc++-v3/README
+++ b/libstdc++-v3/README
@@ -35,13 +35,6 @@ It has subdirectories:
       names into the std:: namespace.
       [NB: this is the default, and is the same as --enable-cheaders=c_std]
 
-    include/c_shadow
-      Headers intended to shadow standard C headers provided by an
-      underlying OS or C library, and other headers depended on directly
-      by C++ headers (e.g. unistd.h).  These are meant to wrap the names
-      defined there into the _C_legacy namespace.
-      [NB: this can be enabled via --enable-cheaders=c_shadow]
-
     include/bits
       Files included by standard headers and by other files in
       the bits directory. 
diff --git a/libstdc++-v3/acconfig.h b/libstdc++-v3/acconfig.h
index c2a96c2248b..cffecbd172f 100644
--- a/libstdc++-v3/acconfig.h
+++ b/libstdc++-v3/acconfig.h
@@ -45,6 +45,9 @@
 // Define if LFS support is available.
 #undef _GLIBCXX_USE_LFS
 
+// Define if a fully dynamic basic_string is wanted.
+#undef _GLIBCXX_FULLY_DYNAMIC_STRING
+
 // Define if NLS translations are to be used.
 #undef _GLIBCXX_USE_NLS
 
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 6e531007cac..6c9f13aa185 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -594,6 +594,25 @@ AC_DEFUN([GLIBCXX_CHECK_LFS], [
 
 
 dnl
+dnl Check for whether a fully dynamic basic_string implementation should
+dnl be turned on, that does not put empty objects in per-process static
+dnl memory (mostly useful together with shared memory allocators, see PR
+dnl libstdc++/16612 for details).
+dnl
+dnl --enable-fully-dynamic-string defines _GLIBCXX_FULLY_DYNAMIC_STRING
+dnl --disable-fully-dynamic-string leaves _GLIBCXX_FULLY_DYNAMIC_STRING undefined
+dnl  +  Usage:  GLIBCXX_ENABLE_FULLY_DYNAMIC_STRING[(DEFAULT)]
+dnl       Where DEFAULT is either `yes' or `no'.
+dnl
+AC_DEFUN([GLIBCXX_ENABLE_FULLY_DYNAMIC_STRING], [
+  GLIBCXX_ENABLE(fully-dynamic-string,$1,,[do not put empty strings in per-process static memory])
+  if test $enable_fully_dynamic_string = yes; then
+    AC_DEFINE(_GLIBCXX_FULLY_DYNAMIC_STRING)
+  fi
+])
+
+
+dnl
 dnl Does any necessary configuration of the testsuite directory.  Generates
 dnl the testsuite_hooks.h header.
 dnl
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index ecb29eb35db..acb7d732abc 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -46,6 +46,9 @@
 // Define if LFS support is available.
 #undef _GLIBCXX_USE_LFS
 
+// Define if a fully dynamic basic_string is wanted.
+#undef _GLIBCXX_FULLY_DYNAMIC_STRING
+
 // Define if NLS translations are to be used.
 #undef _GLIBCXX_USE_NLS
 
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 3c5d7206cff..b38e54980ca 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -884,6 +884,9 @@ Optional Features:
   --enable-cxx-flags=FLAGS
                           pass compiler FLAGS when building library
                           [default=]
+  --enable-fully-dynamic-string
+                          do not put empty strings in per-process static
+                          memory [default=no]
   --enable-symvers=STYLE  enables symbol versioning of the shared library
                           [default=yes]
   --enable-version-specific-runtime-libs
@@ -4394,7 +4397,7 @@ test x"$pic_mode" = xno && libtool_flags="$libtool_flags --prefer-non-pic"
 case $host in
 *-*-irix6*)
   # Find out which ABI we are using.
-  echo '#line 4397 "configure"' > conftest.$ac_ext
+  echo '#line 4400 "configure"' > conftest.$ac_ext
   if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   (eval $ac_compile) 2>&5
   ac_status=$?
@@ -5015,7 +5018,7 @@ fi;
     #
     # Fake what AC_TRY_COMPILE does.  XXX Look at redoing this new-style.
     cat > conftest.$ac_ext << EOF
-#line 5018 "configure"
+#line 5021 "configure"
 struct S { ~S(); };
 void bar();
 void foo()
@@ -7841,6 +7844,29 @@ echo "${ECHO_T}$EXTRA_CXX_FLAGS" >&6
 
 
 
+   # Check whether --enable-fully-dynamic-string or --disable-fully-dynamic-string was given.
+if test "${enable_fully_dynamic_string+set}" = set; then
+  enableval="$enable_fully_dynamic_string"
+
+      case "$enableval" in
+       yes|no) ;;
+       *) { { echo "$as_me:$LINENO: error: Argument to enable/disable fully-dynamic-string must be yes or no" >&5
+echo "$as_me: error: Argument to enable/disable fully-dynamic-string must be yes or no" >&2;}
+   { (exit 1); exit 1; }; } ;;
+      esac
+
+else
+  enable_fully_dynamic_string=no
+fi;
+
+  if test $enable_fully_dynamic_string = yes; then
+    cat >>confdefs.h <<\_ACEOF
+#define _GLIBCXX_FULLY_DYNAMIC_STRING 1
+_ACEOF
+
+  fi
+
+
 # No surprises, no surprises...
 if test $atomicity_dir = cpu/generic ; then
   { echo "$as_me:$LINENO: WARNING: No native atomic operations are provided for this platform." >&5
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index 345136d0743..eb70f8a3de9 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -94,6 +94,7 @@ GLIBCXX_ENABLE_CONCEPT_CHECKS([no])
 GLIBCXX_ENABLE_DEBUG_FLAGS(["-g3 -O0"])
 GLIBCXX_ENABLE_DEBUG([no])
 GLIBCXX_ENABLE_CXX_FLAGS
+GLIBCXX_ENABLE_FULLY_DYNAMIC_STRING([no])
 
 # No surprises, no surprises...
 if test $atomicity_dir = cpu/generic ; then
diff --git a/libstdc++-v3/docs/html/configopts.html b/libstdc++-v3/docs/html/configopts.html
index 8ef9c42eb5d..2c84e969a05 100644
--- a/libstdc++-v3/docs/html/configopts.html
+++ b/libstdc++-v3/docs/html/configopts.html
@@ -144,9 +144,8 @@ options</a></h1>
 
  <dt><code>--enable-cheaders=OPTION  </code></dt>
  <dd><p>This allows the user to define what kind of C headers are
-        used.  Options are: c, c_std, and c_shadow. These correspond
-        to the source directory's include/c, include/c_std, and
-        include/c_shadow directories.  The default is c_std.
+        used.  Options are c and c_std.  These correspond to the source
+	directory's include/c and include/c_std.  The default is c_std.
      </p>
  </dd>
 
@@ -261,6 +260,14 @@ options</a></h1>
      </p>
  </dd>
 
+ <dt><code>--enable-fully-dynamic-string  </code></dt>
+ <dd><p>This option enables a special version of basic_string avoiding
+        the optimization that allocates empty objects in static memory.
+	Mostly useful together with shared memory allocators, see PR
+	libstdc++/16612 for details.
+     </p>
+ </dd>
+
  <dt><code>--enable-concept-checks  </code></dt>
  <dd><p>This turns on additional compile-time checks for instantiated
         library templates, in the form of specialized templates,
diff --git a/libstdc++-v3/docs/html/ext/howto.html b/libstdc++-v3/docs/html/ext/howto.html
index 5670c469768..5b4a69fb1f7 100644
--- a/libstdc++-v3/docs/html/ext/howto.html
+++ b/libstdc++-v3/docs/html/ext/howto.html
@@ -496,6 +496,12 @@
     </dt>
     <dd>Replace &quot;new&quot; with &quot;::new&quot;.
     </dd>
+
+    <dt><a href="lwg-active.html#453">453</a>:
+        <em>basic_stringbuf::seekoff need not always fail for an empty stream</em>
+    </dt>
+    <dd>Don't fail if the next pointer is null and newoff is zero.
+    </dd>
 <!--
     <dt><a href="lwg-defects.html#"></a>:
         <em></em>
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index 7e6c669bd0b..1e79da4b4bd 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -211,7 +211,9 @@ namespace std
 	void
 	_M_dispose(const _Alloc& __a)
 	{
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
 	  if (__builtin_expect(this != &_S_empty_rep(), false))
+#endif
 	    if (__gnu_cxx::__exchange_and_add(&this->_M_refcount, -1) <= 0)
 	      _M_destroy(__a);
 	}  // XXX MT
@@ -222,7 +224,9 @@ namespace std
 	_CharT*
 	_M_refcopy() throw()
 	{
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
 	  if (__builtin_expect(this != &_S_empty_rep(), false))
+#endif
             __gnu_cxx::__atomic_add(&this->_M_refcount, 1);
 	  return _M_refdata();
 	}  // XXX MT
@@ -1957,11 +1961,14 @@ namespace std
 	      size_type __n2) const;
   };
 
-
   template<typename _CharT, typename _Traits, typename _Alloc>
     inline basic_string<_CharT, _Traits, _Alloc>::
     basic_string()
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
     : _M_dataplus(_S_empty_rep()._M_refdata(), _Alloc()) { }
+#else
+    : _M_dataplus(_S_construct(size_type(), _CharT(), _Alloc()), _Alloc()) { }
+#endif
 
   // operator+
   /**
diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc
index 7d27aab970c..49b6362e790 100644
--- a/libstdc++-v3/include/bits/basic_string.tcc
+++ b/libstdc++-v3/include/bits/basic_string.tcc
@@ -88,8 +88,10 @@ namespace std
       _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
 		   input_iterator_tag)
       {
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
 	if (__beg == __end && __a == _Alloc())
 	  return _S_empty_rep()._M_refdata();
+#endif
 	// Avoid reallocation for common case.
 	_CharT __buf[128];
 	size_type __len = 0;
@@ -134,11 +136,12 @@ namespace std
       _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
 		   forward_iterator_tag)
       {
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
 	if (__beg == __end && __a == _Alloc())
 	  return _S_empty_rep()._M_refdata();
-
+#endif
 	// NB: Not required, but considered best practice.
-	if (__builtin_expect(__is_null_pointer(__beg), 0))
+	if (__builtin_expect(__is_null_pointer(__beg) && __beg != __end, 0))
 	  __throw_logic_error(__N("basic_string::_S_construct NULL not valid"));
 
 	const size_type __dnew = static_cast<size_type>(std::distance(__beg,
@@ -162,9 +165,10 @@ namespace std
     basic_string<_CharT, _Traits, _Alloc>::
     _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
     {
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
       if (__n == 0 && __a == _Alloc())
 	return _S_empty_rep()._M_refdata();
-
+#endif
       // Check for out_of_range and length_error exceptions.
       _Rep* __r = _Rep::_S_create(__n, size_type(0), __a);
       if (__n)
@@ -358,8 +362,10 @@ namespace std
     basic_string<_CharT, _Traits, _Alloc>::_Rep::
     _M_destroy(const _Alloc& __a) throw ()
     {
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
       if (this == &_S_empty_rep())
-        return;
+	return;
+#endif
       const size_type __size = sizeof(_Rep_base) +
 	                       (this->_M_capacity + 1) * sizeof(_CharT);
       _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
@@ -369,8 +375,10 @@ namespace std
     void
     basic_string<_CharT, _Traits, _Alloc>::_M_leak_hard()
     {
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
       if (_M_rep() == &_S_empty_rep())
-        return;
+	return;
+#endif
       if (_M_rep()->_M_is_shared())
 	_M_mutate(0, 0, 0);
       _M_rep()->_M_set_leaked();
@@ -385,8 +393,12 @@ namespace std
       const size_type __new_size = __old_size + __len2 - __len1;
       const size_type __how_much = __old_size - __pos - __len1;
 
+#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
       if (_M_rep() == &_S_empty_rep()
 	  || _M_rep()->_M_is_shared() || __new_size > capacity())
+#else
+      if (_M_rep()->_M_is_shared() || __new_size > capacity())
+#endif
 	{
 	  // Must reallocate.
 	  const allocator_type __a = get_allocator();
diff --git a/libstdc++-v3/include/bits/c++config b/libstdc++-v3/include/bits/c++config
index 24e3164e622..4500bb83623 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -35,7 +35,7 @@
 #include <bits/os_defines.h>
 
 // The current version of the C++ library in compressed ISO date format.
-#define __GLIBCXX__ 20040924
+#define __GLIBCXX__ 20041003
 
 // Allow use of "export template." This is currently not a feature
 // that g++ supports.
diff --git a/libstdc++-v3/include/bits/sstream.tcc b/libstdc++-v3/include/bits/sstream.tcc
index 137d6b3fff7..985a0e46d07 100644
--- a/libstdc++-v3/include/bits/sstream.tcc
+++ b/libstdc++-v3/include/bits/sstream.tcc
@@ -47,24 +47,29 @@ namespace std
     pbackfail(int_type __c)
     {
       int_type __ret = traits_type::eof();
-      const bool __testeof = traits_type::eq_int_type(__c, __ret);
-
       if (this->eback() < this->gptr())
 	{
-	  const bool __testeq = traits_type::eq(traits_type::to_char_type(__c),
-						this->gptr()[-1]);
-	  this->gbump(-1);
-
 	  // Try to put back __c into input sequence in one of three ways.
 	  // Order these tests done in is unspecified by the standard.
-	  if (!__testeof && __testeq)
-	    __ret = __c;
-	  else if (__testeof)
-	    __ret = traits_type::not_eof(__c);
+	  const bool __testeof = traits_type::eq_int_type(__c, __ret);
+	  if (!__testeof)
+	    {
+	      const bool __testeq = traits_type::eq(traits_type::
+						    to_char_type(__c),
+						    this->gptr()[-1]);	  
+	      const bool __testout = this->_M_mode & ios_base::out;
+	      if (__testeq || __testout)
+		{
+		  this->gbump(-1);
+		  if (!__testeq)
+		    *this->gptr() = traits_type::to_char_type(__c);
+		  __ret = __c;
+		}
+	    }
 	  else
 	    {
-	      *this->gptr() = traits_type::to_char_type(__c);
-	      __ret = __c;
+	      this->gbump(-1);
+	      __ret = traits_type::not_eof(__c);
 	    }
 	}
       return __ret;
@@ -123,6 +128,7 @@ namespace std
 	{
 	  // Update egptr() to match the actual string end.
 	  _M_update_egptr();
+
 	  if (this->gptr() < this->egptr())
 	    __ret = traits_type::to_int_type(*this->gptr());
 	}
@@ -141,10 +147,11 @@ namespace std
       __testin &= !(__mode & ios_base::out);
       __testout &= !(__mode & ios_base::in);
 
-      if (_M_string.capacity() && (__testin || __testout || __testboth))
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 453. basic_stringbuf::seekoff need not always fail for an empty stream.
+      const char_type* __beg = __testin ? this->eback() : this->pbase();
+      if ((__beg || !__off) && (__testin || __testout || __testboth))
 	{
-	  char_type* __beg = __testin ? this->eback() : this->pbase();
-
 	  _M_update_egptr();
 
 	  off_type __newoffi = __off;
@@ -181,24 +188,24 @@ namespace std
     seekpos(pos_type __sp, ios_base::openmode __mode)
     {
       pos_type __ret =  pos_type(off_type(-1));
-      if (_M_string.capacity())
-	{
-	  off_type __pos (__sp);
-	  const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
-	  const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
-	  char_type* __beg = __testin ? this->eback() : this->pbase();
+      const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
+      const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
 
+      const char_type* __beg = __testin ? this->eback() : this->pbase();
+      if (__beg && (__testin || __testout))
+	{
 	  _M_update_egptr();
 
+	  const off_type __pos(__sp);
 	  const bool __testpos = 0 <= __pos
 	                         && __pos <=  this->egptr() - __beg;
-	  if ((__testin || __testout) && __testpos)
+	  if (__testpos)
 	    {
 	      if (__testin)
 		this->gbump((__beg + __pos) - this->gptr());
 	      if (__testout)
                 this->pbump((__beg + __pos) - this->pptr());
-	      __ret = pos_type(off_type(__pos));
+	      __ret = __sp;
 	    }
 	}
       return __ret;
diff --git a/libstdc++-v3/include/std/std_sstream.h b/libstdc++-v3/include/std/std_sstream.h
index 6b5728b94ce..3420999164c 100644
--- a/libstdc++-v3/include/std/std_sstream.h
+++ b/libstdc++-v3/include/std/std_sstream.h
@@ -111,8 +111,8 @@ namespace std
       */
       explicit
       basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
-      : __streambuf_type(), _M_mode(), _M_string()
-      { _M_stringbuf_init(__mode); }
+      : __streambuf_type(), _M_mode(__mode), _M_string()
+      { }
 
       /**
        *  @brief  Starts with an existing string buffer.
@@ -140,8 +140,7 @@ namespace std
       __string_type
       str() const
       {
-	const bool __testout = this->_M_mode & ios_base::out;
-	if (__testout)
+	if (this->pptr())
 	  {
 	    // The current egptr() may not be the actual string end.
 	    if (this->pptr() > this->egptr())
@@ -169,7 +168,7 @@ namespace std
       }
 
     protected:
-      // Common initialization code for both ctors goes here.
+      // Common initialization code goes here.
       /**
        *  @if maint
        *  @doctodo
@@ -220,7 +219,7 @@ namespace std
 	    // things will quickly blow up.
 	    
 	    // Step 1: Destroy the current internal array.
-	    _M_string = __string_type(__s, __n);
+	    _M_string.assign(__s, __n);
 	    
 	    // Step 2: Use the external array.
 	    _M_sync(__s, 0, 0);
@@ -254,20 +253,19 @@ namespace std
       {
 	const bool __testin = this->_M_mode & ios_base::in;
 	const bool __testout = this->_M_mode & ios_base::out;
-	const __size_type __len = _M_string.size();
+	char_type* __end = __base + _M_string.size();
 
 	if (__testin)
-	  this->setg(__base, __base + __i, __base + __len);
+	  this->setg(__base, __base + __i, __end);
 	if (__testout)
 	  {
 	    this->setp(__base, __base + _M_string.capacity());
 	    this->pbump(__o);
-	    // We need a pointer to the string end anyway, even when
-	    // !__testin: in that case, however, for the correct
-	    // functioning of the streambuf inlines all the get area
-	    // pointers must be identical.
+	    // egptr() always tracks the string end. When !__testin,
+	    // for the correct functioning of the streambuf inlines
+	    // the other get area pointers are identical.
 	    if (!__testin)
-	      this->setg(__base + __len, __base + __len, __base + __len);
+	      this->setg(__end, __end, __end);
 	  }
       }
 
@@ -277,9 +275,8 @@ namespace std
       _M_update_egptr()
       {
 	const bool __testin = this->_M_mode & ios_base::in;
-	const bool __testout = this->_M_mode & ios_base::out;
 
-	if (__testout && this->pptr() > this->egptr())
+	if (this->pptr() && this->pptr() > this->egptr())
 	  if (__testin)
 	    this->setg(this->eback(), this->gptr(), this->pptr());
 	  else
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/putback/char/1.cc b/libstdc++-v3/testsuite/27_io/basic_istream/putback/char/1.cc
index 870d57aa355..b3c64f60d4d 100644
--- a/libstdc++-v3/testsuite/27_io/basic_istream/putback/char/1.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_istream/putback/char/1.cc
@@ -49,11 +49,11 @@ test01()
   is_04.ignore(30);
   is_04.clear();
   state1 = is_04.rdstate();
-  is_04.putback('|');
+  is_04.putback('t');
   VERIFY( is_04.gcount() == 0 );  // DR 60
   state2 = is_04.rdstate();
   VERIFY( state1 == state2 );
-  VERIFY( is_04.peek() == '|' );
+  VERIFY( is_04.peek() == 't' );
 
   // istream& unget()
   is_04.clear();
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/seekg/char/2346-fstream.cc b/libstdc++-v3/testsuite/27_io/basic_istream/seekg/char/2346-fstream.cc
deleted file mode 100644
index 72686f1b699..00000000000
--- a/libstdc++-v3/testsuite/27_io/basic_istream/seekg/char/2346-fstream.cc
+++ /dev/null
@@ -1,89 +0,0 @@
-// 2000-06-29 bkoz
-
-// Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 2, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING.  If not, write to the Free
-// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
-// USA.
-
-// 27.6.1.3 unformatted input functions
-// NB: ostream has a particular "seeks" category. Adopt this for istreams too.
-// @require@ %-*.tst %-*.txt
-// @diff@ %-*.tst %-*.txt
-
-#include <istream>
-#include <fstream>
-#include <testsuite_hooks.h>
-
-const char* s = " lootpack, peanut butter wolf, rob swift, madlib, quasimoto";
-const int times = 10;
-
-void write_rewind(std::iostream& stream)
-{
-  for (int j = 0; j < times; j++) 
-    {
-      bool test __attribute__((unused)) = true;
-      std::streampos begin = stream.tellg();
-      
-      for (int i = 0; i < times; ++i)
-	stream << j << '-' << i << s << '\n';
-      
-      stream.seekg(begin);
-      std::streampos end = stream.tellg(); 
-      std::streampos badpos = std::streampos(std::streambuf::off_type(-1));
-    }
-}
-
-void check_contents(std::iostream& stream)
-{
-  bool test __attribute__((unused)) = true;
-
-  stream.clear();
-  stream.seekg(0, std::ios::beg);
-  int i = 0;
-  int loop = times * times + 2;
-  while (i < loop)
-    {
-      stream.ignore(80, '\n');
-      if (stream.good())
-	++i;
-      else
-	break;
-    }
-  VERIFY( i == times );
-}
-
-// fstream
-// libstdc++/2346
-void test02()
-{	 
-  std::fstream ofstrm;
-  ofstrm.open("istream_seeks-3.txt", std::ios::out);
-  if (!ofstrm)
-    std::abort();
-  write_rewind(ofstrm);
-  ofstrm.close();
-
-  std::fstream ifstrm;
-  ifstrm.open("istream_seeks-3.txt", std::ios::in);
-  check_contents(ifstrm);
-  ifstrm.close();
-}
-
-int main()
-{
-  test02();
-  return 0;
-}
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/seekg/char/2346-sstream.cc b/libstdc++-v3/testsuite/27_io/basic_istream/seekg/char/2346-sstream.cc
deleted file mode 100644
index 60e43c9a78b..00000000000
--- a/libstdc++-v3/testsuite/27_io/basic_istream/seekg/char/2346-sstream.cc
+++ /dev/null
@@ -1,80 +0,0 @@
-// 2000-06-29 bkoz
-
-// Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 2, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING.  If not, write to the Free
-// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
-// USA.
-
-// 27.6.1.3 unformatted input functions
-// NB: ostream has a particular "seeks" category. Adopt this for istreams too.
-
-#include <istream>
-#include <sstream>
-#include <testsuite_hooks.h>
-
-const char* s = " lootpack, peanut butter wolf, rob swift, madlib, quasimoto";
-const int times = 10;
-
-void write_rewind(std::iostream& stream)
-{
-  for (int j = 0; j < times; j++) 
-    {
-      bool test __attribute__((unused)) = true;
-      std::streampos begin = stream.tellg();
-      
-      for (int i = 0; i < times; ++i)
-	stream << j << '-' << i << s << '\n';
-      
-      stream.seekg(begin);
-      std::streampos end = stream.tellg(); 
-      std::streampos badpos = std::streampos(std::streambuf::off_type(-1));
-    }
-}
-
-void check_contents(std::iostream& stream)
-{
-  bool test __attribute__((unused)) = true;
-
-  stream.clear();
-  stream.seekg(0, std::ios::beg);
-  int i = 0;
-  int loop = times * times + 2;
-  while (i < loop)
-    {
-      stream.ignore(80, '\n');
-      if (stream.good())
-	++i;
-      else
-	break;
-    }
-  VERIFY( i == times );
-}
-
-// stringstream
-// libstdc++/2346
-void test03()
-{	 
-  std::stringstream sstrm;
-
-  write_rewind(sstrm);
-  check_contents(sstrm);
-}
-
-int main()
-{
-  test03();
-  return 0;
-}
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/tellg/char/1.cc b/libstdc++-v3/testsuite/27_io/basic_istream/tellg/char/1.cc
index d213d040a11..4bbe40be919 100644
--- a/libstdc++-v3/testsuite/27_io/basic_istream/tellg/char/1.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_istream/tellg/char/1.cc
@@ -31,20 +31,23 @@
 void test01()
 {
   using namespace std;
+  typedef ios::off_type off_type;
   typedef ios::pos_type pos_type;
 
   bool test __attribute__((unused)) = true;
   const char str_lit01[] = "istream_seeks-1.tst";
 
   // in
-  // test default ctors leave things in the same positions...
   istringstream ist1;
   pos_type p3 = ist1.tellg();
 
   ifstream ifs1;
   pos_type p4 = ifs1.tellg();
 
-  VERIFY( p3 == p4 );
+  // N.B. We implement the resolution of DR 453 and
+  // istringstream::tellg() doesn't fail.
+  VERIFY( p3 == pos_type(off_type(0)) );
+  VERIFY( p4 == pos_type(off_type(-1)) );
 
   // in
   // test ctors leave things in the same positions...
diff --git a/libstdc++-v3/testsuite/27_io/basic_ostream/tellp/char/1.cc b/libstdc++-v3/testsuite/27_io/basic_ostream/tellp/char/1.cc
index 5c8caced6f3..27506636b03 100644
--- a/libstdc++-v3/testsuite/27_io/basic_ostream/tellp/char/1.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_ostream/tellp/char/1.cc
@@ -1,6 +1,6 @@
 // 2000-06-29 bkoz
 
-// Copyright (C) 2000, 2003 Free Software Foundation
+// Copyright (C) 2000, 2003, 2004 Free Software Foundation
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -25,24 +25,26 @@
 #include <fstream>
 #include <testsuite_hooks.h>
 
-
 void test01()
 {
   using namespace std;
+  typedef ios::off_type off_type;
   typedef ios::pos_type pos_type;
 
   bool test __attribute__((unused)) = true;
   const char str_lit01[] = "ostream_seeks-1.txt";
 
   // out
-  // test default ctors leave things in the same positions...
   ostringstream ost1;
   pos_type p1 = ost1.tellp();
 
   ofstream ofs1;
   pos_type p2 = ofs1.tellp();
 
-  VERIFY( p1 == p2 );
+  // N.B. We implement the resolution of DR 453 and
+  // ostringstream::tellp() doesn't fail.
+  VERIFY( p1 == pos_type(off_type(0)) );
+  VERIFY( p2 == pos_type(off_type(-1)) );
 
   // out
   // test ctors leave things in the same positions...
diff --git a/libstdc++-v3/testsuite/27_io/basic_ostream/tellp/char/2.cc b/libstdc++-v3/testsuite/27_io/basic_ostream/tellp/char/2.cc
index f82df5d4bb0..acdc3b4cc75 100644
--- a/libstdc++-v3/testsuite/27_io/basic_ostream/tellp/char/2.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_ostream/tellp/char/2.cc
@@ -1,6 +1,6 @@
 // 2000-03-23 bkoz
 
-// Copyright (C) 2000, 2003 Free Software Foundation
+// Copyright (C) 2000, 2003, 2004 Free Software Foundation
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -33,13 +33,13 @@ void test01()
   ostringstream ost;
   pos_type pos1;
   pos1 = ost.tellp();
-  VERIFY( pos1 == pos_type(-1) );
+  VERIFY( pos1 == pos_type(off_type(0)) );
   ost << "RZA ";
   pos1 = ost.tellp();
-  VERIFY( pos1 == pos_type(4) );
+  VERIFY( pos1 == pos_type(off_type(4)) );
   ost << "ghost dog: way of the samurai";
   pos1 = ost.tellp();
-  VERIFY( pos1 == pos_type(33) );
+  VERIFY( pos1 == pos_type(off_type(33)) );
 }                                    
 
 int main()
diff --git a/libstdc++-v3/testsuite/27_io/basic_streambuf/cons/char/1.cc b/libstdc++-v3/testsuite/27_io/basic_streambuf/cons/char/1.cc
index 9400a599bfc..76a344cfe23 100644
--- a/libstdc++-v3/testsuite/27_io/basic_streambuf/cons/char/1.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_streambuf/cons/char/1.cc
@@ -31,69 +31,12 @@
 
 #include <streambuf>
 #include <testsuite_hooks.h>
-
-class testbuf : public std::streambuf
-{
-public:
-
-  // Typedefs:
-  typedef std::streambuf::traits_type traits_type;
-  typedef std::streambuf::char_type char_type;
-
-  testbuf(): std::streambuf() 
-  { }
-
-  bool
-  check_pointers()
-  { 
-    bool test __attribute__((unused)) = true;
-    VERIFY( this->eback() == NULL );
-    VERIFY( this->gptr() == NULL );
-    VERIFY( this->egptr() == NULL );
-    VERIFY( this->pbase() == NULL );
-    VERIFY( this->pptr() == NULL );
-    VERIFY( this->epptr() == NULL );
-    return test;
-  }
-
-  int_type 
-  pub_uflow() 
-  { return (this->uflow()); }
-
-  int_type 
-  pub_overflow(int_type __c = traits_type::eof()) 
-  { return (this->overflow(__c)); }
-
-  int_type 
-  pub_pbackfail(int_type __c) 
-  { return (this->pbackfail(__c)); }
-
-  void 
-  pub_setg(char* beg, char* cur, char *end) 
-  { this->setg(beg, cur, end); }
-
-  void 
-  pub_setp(char* beg, char* end) 
-  { this->setp(beg, end); }
-
-protected:
-  int_type 
-  underflow() 
-  { 
-    int_type __retval = traits_type::eof();
-    if (this->gptr() < this->egptr())
-      __retval = traits_type::not_eof(0); 
-    return __retval;
-  }
-};
+#include <testsuite_io.h>
 
 void test01()
 {
-  typedef testbuf::traits_type traits_type;
-  typedef testbuf::int_type int_type;
-
   bool test __attribute__((unused)) = true;
-  testbuf buf01;
+  __gnu_test::constraint_streambuf buf01;
 
   // 27.5.2.1 basic_streambuf ctors
   // default ctor initializes 
diff --git a/libstdc++-v3/testsuite/27_io/basic_streambuf/cons/wchar_t/1.cc b/libstdc++-v3/testsuite/27_io/basic_streambuf/cons/wchar_t/1.cc
index a97b35f4d11..1721e4a820a 100644
--- a/libstdc++-v3/testsuite/27_io/basic_streambuf/cons/wchar_t/1.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_streambuf/cons/wchar_t/1.cc
@@ -32,69 +32,12 @@
 
 #include <streambuf>
 #include <testsuite_hooks.h>
-
-class testbuf : public std::wstreambuf
-{
-public:
-
-  // Typedefs:
-  typedef std::wstreambuf::traits_type traits_type;
-  typedef std::wstreambuf::char_type char_type;
-
-  testbuf(): std::wstreambuf() 
-  { }
-
-  bool
-  check_pointers()
-  { 
-    bool test __attribute__((unused)) = true;
-    VERIFY( this->eback() == NULL );
-    VERIFY( this->gptr() == NULL );
-    VERIFY( this->egptr() == NULL );
-    VERIFY( this->pbase() == NULL );
-    VERIFY( this->pptr() == NULL );
-    VERIFY( this->epptr() == NULL );
-    return test;
-  }
-
-  int_type 
-  pub_uflow() 
-  { return (this->uflow()); }
-
-  int_type 
-  pub_overflow(int_type __c = traits_type::eof()) 
-  { return (this->overflow(__c)); }
-
-  int_type 
-  pub_pbackfail(int_type __c) 
-  { return (this->pbackfail(__c)); }
-
-  void 
-  pub_setg(wchar_t* beg, wchar_t* cur, wchar_t* end) 
-  { this->setg(beg, cur, end); }
-
-  void 
-  pub_setp(wchar_t* beg, wchar_t* end) 
-  { this->setp(beg, end); }
-
-protected:
-  int_type 
-  underflow() 
-  { 
-    int_type __retval = traits_type::eof();
-    if (this->gptr() < this->egptr())
-      __retval = traits_type::not_eof(0); 
-    return __retval;
-  }
-};
+#include <testsuite_io.h>
 
 void test01()
 {
-  typedef testbuf::traits_type traits_type;
-  typedef testbuf::int_type int_type;
-
   bool test __attribute__((unused)) = true;
-  testbuf buf01;
+  __gnu_test::constraint_wstreambuf buf01;
 
   // 27.5.2.1 basic_streambuf ctors
   // default ctor initializes 
diff --git a/libstdc++-v3/testsuite/lib/libstdc++.exp b/libstdc++-v3/testsuite/lib/libstdc++.exp
index 0b3b82b887e..2e8db1f4f5a 100644
--- a/libstdc++-v3/testsuite/lib/libstdc++.exp
+++ b/libstdc++-v3/testsuite/lib/libstdc++.exp
@@ -82,7 +82,7 @@ proc libstdc++_init { testfile } {
     global cxx cxxflags
     global includes
     global gluefile wrap_flags
-    global ld_library_path original_ld_library_path
+    global original_ld_library_path
     global target_triplet
 
     set blddir [lookfor_file [get_multilibs] libstdc++-v3]
diff --git a/libstdc++-v3/testsuite/testsuite_io.h b/libstdc++-v3/testsuite/testsuite_io.h
index e5e342eed14..809d0801c6d 100644
--- a/libstdc++-v3/testsuite/testsuite_io.h
+++ b/libstdc++-v3/testsuite/testsuite_io.h
@@ -1,7 +1,7 @@
 // -*- C++ -*-
-// Testing filebuf for the C++ library testsuite.
+// Testing streambuf/filebuf/stringbuf for the C++ library testsuite.
 //
-// Copyright (C) 2003 Free Software Foundation, Inc.
+// Copyright (C) 2003, 2004 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -32,6 +32,7 @@
 #define _GLIBCXX_TESTSUITE_IO_H
 
 #include <fstream>
+#include <sstream>
 
 namespace __gnu_test
 {  
@@ -44,34 +45,60 @@ namespace __gnu_test
   //   Joint file position
   // 27.8.1.4 - Overridden virtual functions p9
   //   If unbuffered, pbase == pptr == NULL
-  class constraint_filebuf: public std::filebuf
-  {
-  public:
-    bool
-    write_position() 
-    { 
-      bool two = this->pptr() != NULL; 
-      bool one = this->pptr() < this->epptr();
-      return one && two;
-    }
-
-    bool
-    read_position()
-    { 
-      bool one = this->gptr() != NULL; 
-      bool two = this->gptr() < this->egptr();
-
-      return one && two;
-    }
-
-    bool
-    unbuffered() 
-    { 
-      bool one = this->pbase() == NULL; 
-      bool two = this->pptr() == NULL; 
-      return one && two;
-    }    
-  };
+  // 27.7.1.1 - Basic_stringbuf constructors p 1
+  // 27.8.1.2 - Basic_filebuf constructors p 1
+  //   ... , initializing the base class with basic_streambuf() 27.5.2.1
+  template<typename T>
+    class constraint_buf
+    : public T
+    {
+    public:
+      bool
+      write_position() 
+      { 
+	bool one = this->pptr() != NULL; 
+	bool two = this->pptr() < this->epptr();
+	return one && two;
+      }
+      
+      bool
+      read_position()
+      { 
+	bool one = this->gptr() != NULL; 
+	bool two = this->gptr() < this->egptr();
+	return one && two;
+      }
+      
+      bool
+      unbuffered() 
+      { 
+	bool one = this->pbase() == NULL; 
+	bool two = this->pptr() == NULL; 
+	return one && two;
+      }
+  
+      bool
+      check_pointers()
+      {
+	bool one   = this->eback() == NULL;
+	bool two   = this->gptr() == NULL;
+	bool three = this->egptr() == NULL;
+	
+	bool four  = this->pbase() == NULL;
+	bool five  = this->pptr() == NULL;
+	bool six   = this->epptr() == NULL;
+	return one && two && three && four && five && six;
+      }
+    };
+
+  typedef  constraint_buf<std::streambuf>   constraint_streambuf;
+  typedef  constraint_buf<std::filebuf>     constraint_filebuf;
+  typedef  constraint_buf<std::stringbuf>   constraint_stringbuf;
+#ifdef _GLIBCXX_USE_WCHAR_T
+  typedef  constraint_buf<std::wstreambuf>  constraint_wstreambuf;
+  typedef  constraint_buf<std::wfilebuf>    constraint_wfilebuf;
+  typedef  constraint_buf<std::wstringbuf>  constraint_wstringbuf;
+#endif
 
   // Used to check if basic_streambuf::pubsync() has been called.
   // This is useful for checking if a function creates [io]stream::sentry