obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.

18 files changed, 1743 insertions, 0 deletions

diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-in.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-in.cc
new file mode 100644
index 000000000..248874617
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-in.cc
@@ -0,0 +1,124 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009, 2010 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "seekoff.txt";
+
+void test05() 
+{
+  using namespace std;
+  using namespace __gnu_test;
+
+  typedef filebuf::int_type 	int_type;
+  typedef filebuf::pos_type 	pos_type;
+  typedef filebuf::off_type 	off_type;
+  typedef filebuf::traits_type 	traits_type;
+
+  bool test __attribute__((unused)) = true;
+  streamsize 			strmsz_1;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekoff
+  // pubseekoff(off_type off, ios_base::seekdir way, ios_base::openmode which)
+  // alters the stream position to off
+
+  // in
+  {
+    constraint_filebuf fb;
+    fb.open(name_01, ios_base::in);
+    VERIFY( !fb.write_position() );
+
+    //beg
+    strmsz_1 = fb.in_avail(); 
+    pt_1 = fb.pubseekoff(2, ios_base::beg);
+    fb.in_avail(); 
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == '9' );
+    fb.pubseekoff(3, ios_base::beg);
+    c2 = fb.sputc('\n');  //current in pointer +1
+    fb.pubseekoff(4, ios_base::beg);
+    c3 = fb.sgetc();
+    VERIFY( c2 == traits_type::eof() ); 
+    VERIFY( c3 == '9' );
+    fb.pubsync(); 
+    c1 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //cur
+    pt_2 = fb.pubseekoff(2, ios_base::cur);
+    off_2 = off_type(pt_2);
+    VERIFY( (off_2 == (off_1 + 2 + 1 + 1)) );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == '1' );
+    fb.pubseekoff(0, ios_base::cur);
+    c2 = fb.sputc('x');  //test current out pointer
+    c3 = fb.sputc('\n');
+    VERIFY( c2 == traits_type::eof() );
+    VERIFY( c3 == traits_type::eof() );
+    fb.pubseekoff(0, ios_base::cur);
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //end
+    pt_2 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_2);
+    VERIFY( off_1 > off_2 ); //weak, but don't know exactly where it ends
+    c3 = fb.sputc('\n');
+    strmsz_1 = fb.sputn("because because because. . .", 28);  
+    VERIFY( strmsz_1 == 0 );
+    fb.pubseekoff(-1, ios_base::end);
+    fb.sgetc();
+    c1 = fb.sungetc();
+    // Defect?  retval of sungetc is not necessarily the character ungotten.
+    // So re-get it.
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+    VERIFY( !fb.write_position() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-io.cc
new file mode 100644
index 000000000..4dc6d8648
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-io.cc
@@ -0,0 +1,124 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009, 2010 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+// { dg-require-binary-io "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "seekoff-1io.tst";
+
+void test05() 
+{
+  using namespace std;
+  using namespace __gnu_test;
+
+  typedef filebuf::int_type 	int_type;
+  typedef filebuf::pos_type 	pos_type;
+  typedef filebuf::off_type 	off_type;
+
+  bool test __attribute__((unused)) = true;
+  streamsize 			strmsz_1;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekoff
+  // pubseekoff(off_type off, ios_base::seekdir way, ios_base::openmode which)
+  // alters the stream position to off
+
+  // in | out
+  {
+    constraint_filebuf fb;
+    fb.open(name_01, ios_base::out | ios_base::in);
+    VERIFY( !fb.write_position() );
+    VERIFY( !fb.read_position() );
+
+    //beg
+    strmsz_1 = fb.in_avail(); 
+    pt_1 = fb.pubseekoff(2, ios_base::beg);
+    fb.in_avail(); 
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == '9' );
+    fb.pubseekoff(3, ios_base::beg);
+    c2 = fb.sputc('\n');  //current in pointer +1
+    fb.pubseekoff(4, ios_base::beg);
+    c3 = fb.sgetc();
+    VERIFY( c2 != c3 ); 
+    VERIFY( c3 == '9' );
+    fb.pubsync(); 
+    c1 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //cur
+    pt_2 = fb.pubseekoff(2, ios_base::cur);
+    off_2 = off_type(pt_2);
+    VERIFY( (off_2 == (off_1 + 2 + 1 + 1)) );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == '1' );
+    fb.pubseekoff(0, ios_base::cur);
+    c2 = fb.sputc('x');  //test current out pointer
+    c3 = fb.sputc('\n');
+    fb.pubseekoff(0, ios_base::cur);
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //end
+    pt_2 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_2);
+    VERIFY( off_1 > off_2 ); //weak, but don't know exactly where it ends
+    c3 = fb.sputc('\n');
+    strmsz_1 = fb.sputn("because because because. . .", 28);  
+    VERIFY( strmsz_1 == 28 );
+    fb.pubseekoff(-1, ios_base::end);
+    fb.sgetc();
+    c1 = fb.sungetc();
+    // Defect?  retval of sungetc is not necessarily the character ungotten.
+    // So re-get it.
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+    VERIFY( !fb.write_position() );
+    VERIFY( fb.read_position() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-out.cc
new file mode 100644
index 000000000..8d7ab1dfc
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-out.cc
@@ -0,0 +1,124 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009, 2010 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "seekoff-1out.tst";
+
+void test05() 
+{
+  using namespace std;
+  using namespace __gnu_test;
+
+  typedef filebuf::int_type 	int_type;
+  typedef filebuf::pos_type 	pos_type;
+  typedef filebuf::off_type 	off_type;
+  typedef filebuf::traits_type 	traits_type;
+
+  bool test __attribute__((unused)) = true;
+  streamsize 			strmsz_1;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekoff
+  // pubseekoff(off_type off, ios_base::seekdir way, ios_base::openmode which)
+  // alters the stream position to off
+
+  // out
+  {
+    constraint_filebuf fb;
+    fb.open(name_01, ios_base::out);
+    VERIFY( !fb.write_position() );
+    VERIFY( !fb.read_position() );
+
+    //beg
+    strmsz_1 = fb.in_avail(); 
+    pt_1 = fb.pubseekoff(2, ios_base::beg);
+    fb.in_avail(); 
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == traits_type::eof() );
+    fb.pubseekoff(3, ios_base::beg);
+    c2 = fb.sputc('\n');  //current in pointer +1
+    fb.pubseekoff(4, ios_base::beg);
+    c3 = fb.sgetc();
+    VERIFY( c2 != c3 ); 
+    VERIFY( c3 == traits_type::eof() );
+    fb.pubsync(); 
+    c1 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //cur
+    pt_2 = fb.pubseekoff(2, ios_base::cur);
+    off_2 = off_type(pt_2);
+    VERIFY( (off_2 == (off_1 + 2 + 1 + 1)) );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == traits_type::eof() );
+    fb.pubseekoff(0, ios_base::cur);
+    c2 = fb.sputc('x');  //test current out pointer
+    c3 = fb.sputc('\n');
+    fb.pubseekoff(0, ios_base::cur);
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //end
+    pt_2 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_2);
+    VERIFY( off_1 > off_2 ); //weak, but don't know exactly where it ends
+    c3 = fb.sputc('\n');
+    strmsz_1 = fb.sputn("because because because. . .", 28);  
+    VERIFY( strmsz_1 == 28 );
+    fb.pubseekoff(-1, ios_base::end);
+    fb.sgetc();
+    c1 = fb.sungetc();
+    // Defect?  retval of sungetc is not necessarily the character ungotten.
+    // So re-get it.
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+    VERIFY( !fb.write_position() );
+    VERIFY( !fb.read_position() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/11543.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/11543.cc
new file mode 100644
index 000000000..2f6cf2988
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/11543.cc
@@ -0,0 +1,153 @@
+// Copyright (C) 2003, 2009
+// 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <locale>
+#include <testsuite_hooks.h>
+
+struct MyState
+{
+};
+
+struct MyCharTraits : std::char_traits<char>
+{
+  typedef std::fpos<MyState> pos_type;
+  typedef MyState state_type;
+};
+
+namespace std
+{
+  template <>
+    class codecvt<char, char, MyState> :
+      public locale::facet, public codecvt_base
+    {
+    public:
+      typedef char intern_type;
+      typedef char extern_type;
+      typedef MyState state_type;
+    
+      explicit codecvt(size_t refs = 0)
+      : locale::facet(refs) { }
+    
+      result out(state_type& state, const intern_type* from,
+		 const intern_type* from_end,  const intern_type*& from_next,
+		 extern_type* to, extern_type* to_limit,
+		 extern_type*& to_next) const
+      { return do_out(state, from, from_end, from_next,
+		      to, to_limit, to_next); }
+
+      result unshift(state_type& state, extern_type* to, extern_type* to_limit,
+		     extern_type*& to_next) const
+      { return do_unshift(state, to, to_limit, to_next); }
+
+      result in(state_type& state, const extern_type* from,
+		const extern_type* from_end, const extern_type*& from_next,
+		intern_type* to, intern_type* to_limit,
+		intern_type*& to_next) const
+      { return do_in(state, from, from_end, from_next,
+		     to, to_limit, to_next); }
+
+      int encoding() const throw()
+      { return do_encoding(); }
+      
+      bool always_noconv() const throw()
+      { return do_always_noconv(); }
+
+      int length(state_type& state, const extern_type* from,
+		 const extern_type* end, size_t max) const
+      { return do_length(state, from, end, max); }
+
+      int max_length() const throw()
+      { return do_max_length(); }
+    
+      static locale::id id;
+    
+    protected:
+      virtual ~codecvt();
+
+      virtual result do_out(state_type&, const intern_type* from,
+			    const intern_type*, const intern_type*& from_next,
+			    extern_type* to, extern_type*,
+			    extern_type*& to_next) const
+      {
+	from_next = from;
+	to_next = to;
+	return noconv;
+      }
+
+      virtual result do_in(state_type&, const extern_type* from,
+			   const extern_type*, const extern_type*& from_next,
+			   intern_type* to, intern_type*,
+			   intern_type*& to_next) const
+      {
+	from_next = from;
+	to_next = to;
+	return noconv;
+      }
+
+      virtual result do_unshift(state_type&, extern_type*, extern_type*,
+				extern_type*&) const
+      { return noconv; }
+
+      virtual int do_encoding() const throw()
+      { return 1; }
+
+      virtual bool do_always_noconv() const throw()
+      { return true; }
+
+      virtual int do_length(state_type&, const extern_type* from,
+			    const extern_type* end, size_t max) const
+      {
+	size_t len = end - from;
+	return std::min(max, len);
+      }
+
+      virtual int do_max_length() const throw()
+      { return 1; }
+    };
+  
+  locale::id codecvt<char, char, MyState>::id;
+
+  codecvt<char, char, MyState>::~codecvt()
+  { }
+}
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  std::locale loc(std::locale::classic(),
+		  new std::codecvt<char, char, MyState>);
+  std::basic_filebuf<char, MyCharTraits> fb;
+  fb.pubimbue(loc);
+  fb.open("tmp_11543", std::ios_base::out);
+  VERIFY( fb.is_open() );
+  MyCharTraits::pos_type pos = fb.pubseekoff(0, std::ios_base::beg);
+  VERIFY( pos != MyCharTraits::pos_type(MyCharTraits::off_type(-1)) );
+  fb.close();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12232.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12232.cc
new file mode 100644
index 000000000..a60293274
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12232.cc
@@ -0,0 +1,71 @@
+// Copyright (C) 2003, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+#include <fstream>
+#include <testsuite_hooks.h>
+
+const char name[] = "tmp_12232";
+
+// libstdc++/12232
+void test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;
+
+  filebuf fbout;
+  fbout.open(name, ios_base::out);
+  fbout.sputn("abc", 3);
+  
+  streampos p1 = fbout.pubseekoff(0, ios_base::cur, ios_base::in);
+  VERIFY( p1 != streampos(-1) );
+  fbout.sputn("de", 2);
+  
+  streampos p2 = fbout.pubseekpos(p1, ios_base::openmode());
+  VERIFY( p2 != streampos(-1) );
+  fbout.sputn("34", 2);
+  
+  streampos p3 = fbout.pubseekoff(0, ios_base::beg, ios_base::ate);
+  VERIFY( p3 != streampos(-1) );
+  fbout.sputn("012", 3);
+  
+  fbout.close();
+  
+  filebuf fbin;
+  fbin.open(name, ios_base::in);
+  
+  streampos p4 = fbin.pubseekoff(0, ios_base::beg, ios_base::ate);
+  VERIFY( p4 != streampos(-1) );
+  VERIFY( fbin.sgetc() == '0' );
+  
+  streampos p5 = fbin.pubseekoff(-1, ios_base::end, ios_base::out);
+  VERIFY( p5 != streampos(-1) );
+  VERIFY( fbin.sbumpc() == '4' );
+  
+  streampos p6 = fbin.pubseekpos(p4, ios_base::binary);
+  VERIFY( p6 != streampos(-1) );
+  VERIFY( fbin.sbumpc() == '0' );
+  
+  fbin.close();
+}
+
+int main()
+{
+  void test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-1.cc
new file mode 100644
index 000000000..d2860cbf5
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-1.cc
@@ -0,0 +1,80 @@
+// Copyright (C) 2003, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<char, char, std::mbstate_t>
+{
+public:
+  mutable bool unshift_called;
+
+  Cvt()
+  : unshift_called(false)
+  { }
+
+protected:
+  bool
+  do_always_noconv() const throw()
+  { return false; }
+
+  int
+  do_encoding() const throw()
+  { return -1; }
+
+  std::codecvt_base::result
+  do_unshift(std::mbstate_t&, char* to, char*, char*& to_next) const
+  {
+    unshift_called = true;
+    to_next = to;
+    return std::codecvt_base::ok;
+  }
+};
+
+// libstdc++/12790
+// basic_filebuf::seekoff() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekoff_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  filebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  fb.sputc('a');
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekoff(0, ios_base::cur);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-2.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-2.cc
new file mode 100644
index 000000000..f0f1b9938
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-2.cc
@@ -0,0 +1,81 @@
+// Copyright (C) 2003, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<char, char, std::mbstate_t>
+{
+public:
+  mutable bool unshift_called;
+
+  Cvt()
+  : unshift_called(false)
+  { }
+
+protected:
+  bool
+  do_always_noconv() const throw()
+  { return false; }
+
+  int
+  do_encoding() const throw()
+  { return -1; }
+
+  std::codecvt_base::result
+  do_unshift(std::mbstate_t&, char* to, char*, char*& to_next) const
+  {
+    unshift_called = true;
+    to_next = to;
+    return std::codecvt_base::ok;
+  }
+};
+
+// libstdc++/12790
+// basic_filebuf::seekoff() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekoff_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  filebuf fb;
+  fb.pubsetbuf(0, 0);
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  fb.sputc('a');
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekoff(0, ios_base::cur);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-3.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-3.cc
new file mode 100644
index 000000000..026d75029
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-3.cc
@@ -0,0 +1,80 @@
+// Copyright (C) 2003, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<char, char, std::mbstate_t>
+{
+public:
+  mutable bool unshift_called;
+
+  Cvt()
+  : unshift_called(false)
+  { }
+
+protected:
+  bool
+  do_always_noconv() const throw()
+  { return false; }
+
+  int
+  do_encoding() const throw()
+  { return -1; }
+
+  std::codecvt_base::result
+  do_unshift(std::mbstate_t&, char* to, char*, char*& to_next) const
+  {
+    unshift_called = true;
+    to_next = to;
+    return std::codecvt_base::ok;
+  }
+};
+
+// libstdc++/12790
+// basic_filebuf::seekoff() should call codecvt::unshift(),
+// but only if writing
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekoff_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  filebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekoff(0, ios_base::cur);
+  VERIFY( !cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-4.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-4.cc
new file mode 100644
index 000000000..60813c899
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-4.cc
@@ -0,0 +1,81 @@
+// Copyright (C) 2003, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<char, char, std::mbstate_t>
+{
+public:
+  mutable bool unshift_called;
+
+  Cvt()
+  : unshift_called(false)
+  { }
+
+protected:
+  bool
+  do_always_noconv() const throw()
+  { return false; }
+
+  int
+  do_encoding() const throw()
+  { return -1; }
+
+  std::codecvt_base::result
+  do_unshift(std::mbstate_t&, char* to, char*, char*& to_next) const
+  {
+    unshift_called = true;
+    to_next = to;
+    return std::codecvt_base::ok;
+  }
+};
+
+// libstdc++/12790
+// basic_filebuf::seekoff() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekoff_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  filebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  fb.sputc('a');
+  fb.pubsync(); // Does not call unshift()
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekoff(0, ios_base::cur);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-in.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-in.cc
new file mode 100644
index 000000000..3a8809da2
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-in.cc
@@ -0,0 +1,125 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009, 2010 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "seekoff.txt";
+
+void test05() 
+{
+  using namespace std;
+  using namespace __gnu_test;
+
+  typedef filebuf::int_type 	int_type;
+  typedef filebuf::pos_type 	pos_type;
+  typedef filebuf::off_type 	off_type;
+  typedef filebuf::traits_type 	traits_type;
+
+  bool test __attribute__((unused)) = true;
+  streamsize 			strmsz_1;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekoff
+  // pubseekoff(off_type off, ios_base::seekdir way, ios_base::openmode which)
+  // alters the stream position to off
+
+  // in
+  {
+    constraint_filebuf fb;
+    fb.pubsetbuf(0, 0);
+    fb.open(name_01, ios_base::in);
+    VERIFY( fb.unbuffered() );
+
+    //beg
+    strmsz_1 = fb.in_avail(); 
+    pt_1 = fb.pubseekoff(2, ios_base::beg);
+    fb.in_avail(); 
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == '9' );
+    fb.pubseekoff(3, ios_base::beg);
+    c2 = fb.sputc('\n');  //current in pointer +1
+    fb.pubseekoff(4, ios_base::beg);
+    c3 = fb.sgetc();
+    VERIFY( c2 == traits_type::eof() ); 
+    VERIFY( c3 == '9' );
+    fb.pubsync(); 
+    c1 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //cur
+    pt_2 = fb.pubseekoff(2, ios_base::cur);
+    off_2 = off_type(pt_2);
+    VERIFY( (off_2 == (off_1 + 2 + 1 + 1)) );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == '1' );
+    fb.pubseekoff(0, ios_base::cur);
+    c2 = fb.sputc('x');  //test current out pointer
+    c3 = fb.sputc('\n');
+    VERIFY( c2 == traits_type::eof() );
+    VERIFY( c3 == traits_type::eof() );
+    fb.pubseekoff(0, ios_base::cur);
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //end
+    pt_2 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_2);
+    VERIFY( off_1 > off_2 ); //weak, but don't know exactly where it ends
+    c3 = fb.sputc('\n');
+    strmsz_1 = fb.sputn("because because because. . .", 28);  
+    VERIFY( strmsz_1 == 0 );
+    fb.pubseekoff(-1, ios_base::end);
+    fb.sgetc();
+    c1 = fb.sungetc();
+    // Defect?  retval of sungetc is not necessarily the character ungotten.
+    // So re-get it.
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+    VERIFY( fb.unbuffered() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-io.cc
new file mode 100644
index 000000000..89fab2aed
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-io.cc
@@ -0,0 +1,123 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009, 2010 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+// { dg-require-binary-io "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "seekoff-2io.tst";
+
+void test05() 
+{
+  using namespace std;
+  using namespace __gnu_test;
+
+  typedef filebuf::int_type 	int_type;
+  typedef filebuf::pos_type 	pos_type;
+  typedef filebuf::off_type 	off_type;
+
+  bool test __attribute__((unused)) = true;
+  streamsize 			strmsz_1;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekoff
+  // pubseekoff(off_type off, ios_base::seekdir way, ios_base::openmode which)
+  // alters the stream position to off
+
+  // in | out
+  {
+    constraint_filebuf fb;
+    fb.pubsetbuf(0, 0);
+    fb.open(name_01, ios_base::out | ios_base::in);
+    VERIFY( fb.unbuffered() );
+
+    //beg
+    strmsz_1 = fb.in_avail(); 
+    pt_1 = fb.pubseekoff(2, ios_base::beg);
+    fb.in_avail(); 
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == '9' );
+    fb.pubseekoff(3, ios_base::beg);
+    c2 = fb.sputc('\n');  //current in pointer +1
+    fb.pubseekoff(4, ios_base::beg);
+    c3 = fb.sgetc();
+    VERIFY( c2 != c3 ); 
+    VERIFY( c3 == '9' );
+    fb.pubsync(); 
+    c1 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //cur
+    pt_2 = fb.pubseekoff(2, ios_base::cur);
+    off_2 = off_type(pt_2);
+    VERIFY( (off_2 == (off_1 + 2 + 1 + 1)) );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == '1' );
+    fb.pubseekoff(0, ios_base::cur);
+    c2 = fb.sputc('x');  //test current out pointer
+    c3 = fb.sputc('\n');
+    fb.pubseekoff(0, ios_base::cur);
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //end
+    pt_2 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_2);
+    VERIFY( off_1 > off_2 ); //weak, but don't know exactly where it ends
+    c3 = fb.sputc('\n');
+    strmsz_1 = fb.sputn("because because because. . .", 28);  
+    VERIFY( strmsz_1 == 28 );
+    fb.pubseekoff(-1, ios_base::end);
+    fb.sgetc();
+    c1 = fb.sungetc();
+    // Defect?  retval of sungetc is not necessarily the character ungotten.
+    // So re-get it.
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+    VERIFY( fb.unbuffered() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-out.cc
new file mode 100644
index 000000000..b1ad66e89
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/2-out.cc
@@ -0,0 +1,123 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009, 2010 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "seekoff-2out.tst";
+
+void test05() 
+{
+  using namespace std;
+  using namespace __gnu_test;
+
+  typedef filebuf::int_type 	int_type;
+  typedef filebuf::pos_type 	pos_type;
+  typedef filebuf::off_type 	off_type;
+  typedef filebuf::traits_type 	traits_type;
+
+  bool test __attribute__((unused)) = true;
+  streamsize 			strmsz_1;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekoff
+  // pubseekoff(off_type off, ios_base::seekdir way, ios_base::openmode which)
+  // alters the stream position to off
+
+  // out
+  {
+    constraint_filebuf fb;
+    fb.pubsetbuf(0, 0);
+    fb.open(name_01, ios_base::out);
+    VERIFY( fb.unbuffered() );
+
+    //beg
+    strmsz_1 = fb.in_avail(); 
+    pt_1 = fb.pubseekoff(2, ios_base::beg);
+    fb.in_avail(); 
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == traits_type::eof() );
+    fb.pubseekoff(3, ios_base::beg);
+    c2 = fb.sputc('\n');  //current in pointer +1
+    fb.pubseekoff(4, ios_base::beg);
+    c3 = fb.sgetc();
+    VERIFY( c2 != c3 ); 
+    VERIFY( c3 == traits_type::eof() );
+    fb.pubsync(); 
+    c1 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //cur
+    pt_2 = fb.pubseekoff(2, ios_base::cur);
+    off_2 = off_type(pt_2);
+    VERIFY( (off_2 == (off_1 + 2 + 1 + 1)) );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == traits_type::eof() );
+    fb.pubseekoff(0, ios_base::cur);
+    c2 = fb.sputc('x');  //test current out pointer
+    c3 = fb.sputc('\n');
+    fb.pubseekoff(0, ios_base::cur);
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+
+    //end
+    pt_2 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_2);
+    VERIFY( off_1 > off_2 ); //weak, but don't know exactly where it ends
+    c3 = fb.sputc('\n');
+    strmsz_1 = fb.sputn("because because because. . .", 28);  
+    VERIFY( strmsz_1 == 28 );
+    fb.pubseekoff(-1, ios_base::end);
+    fb.sgetc();
+    c1 = fb.sungetc();
+    // Defect?  retval of sungetc is not necessarily the character ungotten.
+    // So re-get it.
+    c1 = fb.sgetc();
+    fb.pubsync(); 
+    c3 = fb.sgetc();
+    VERIFY( c1 == c3 );
+    VERIFY( fb.unbuffered() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/26777.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/26777.cc
new file mode 100644
index 000000000..d98234bab
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/26777.cc
@@ -0,0 +1,90 @@
+// { dg-require-fork "" }
+// { dg-require-mkfifo "" }
+
+// 2006-03-22  Paolo Carlini  <pcarlini@suse.de>
+
+// Copyright (C) 2006, 2007, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// No asserts, avoid leaking the semaphores if a VERIFY fails.
+#undef _GLIBCXX_ASSERT
+
+#include <testsuite_hooks.h>
+#include <fstream>
+#include <sstream>
+#include <cstdlib>
+#include <unistd.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+// libstdc++/26777
+bool test01()
+{
+  using namespace std;
+  using namespace __gnu_test;
+
+  bool test __attribute__((unused)) = true;
+
+  const char* name = "tmp_fifo6";
+
+  signal(SIGPIPE, SIG_IGN);
+
+  unlink(name);  
+  mkfifo(name, S_IRWXU);
+  semaphore s1, s2;
+
+  int child = fork();
+  VERIFY( child != -1 );
+
+  if (child == 0)
+    {
+      filebuf fbout;
+      fbout.open(name, ios_base::in | ios_base::out);
+      VERIFY( fbout.is_open() );
+      fbout.sputn("Whatever", 8);
+      fbout.pubsync();
+      s1.signal();
+      s2.wait();
+      fbout.close();
+      s1.signal();
+      exit(0);
+    }
+
+  filebuf fbin;
+  fbin.open(name, ios::in);
+  s1.wait();
+
+  fbin.sgetc();
+  fbin.pubseekoff(0, ios::cur, ios::in);
+  s2.signal();
+  s1.wait();
+
+  ostringstream oss;
+  oss << &fbin;
+  fbin.close();
+
+  VERIFY( oss.str() == "Whatever" );
+
+  return test;
+}
+
+int main()
+{
+  return !test01();
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-in.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-in.cc
new file mode 100644
index 000000000..a0c4d5a86
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-in.cc
@@ -0,0 +1,63 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.7.1.3 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+
+void test02(std::filebuf& in, bool pass)
+{
+  bool test __attribute__((unused)) = true;
+  using namespace std;
+  typedef streambuf::pos_type pos_type;
+  typedef streambuf::off_type off_type;
+  pos_type bad = pos_type(off_type(-1));
+  pos_type p = 0;
+
+  // seekoff
+  p = in.pubseekoff(0, ios_base::beg, ios_base::in);
+  VERIFY( pass == (p != bad) );
+
+  p = in.pubseekoff(0, ios_base::beg, ios_base::out);
+  VERIFY( pass == (p != bad) );  // See libstdc++/12232
+
+  p = in.pubseekoff(0, ios_base::beg); 
+  VERIFY( pass == (p != bad) );
+}
+
+const char name_01[] = "filebuf_virtuals-1.tst"; // file with data in it
+const char name_03[] = "filebuf_members-1.tst"; // empty file
+
+int main() 
+{
+  using namespace std;
+
+  filebuf in1;
+  in1.open(name_01, ios_base::in);
+  filebuf in2;
+  filebuf in3;
+  in3.open(name_03, ios_base::in);
+  test02(in1, true);
+  test02(in2, false);
+  test02(in3, true);
+  return 0;
+}
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
new file mode 100644
index 000000000..803a81f27
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-io.cc
@@ -0,0 +1,66 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.7.1.3 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+
+void test02(std::filebuf& in, bool pass)
+{
+  bool test __attribute__((unused)) = true;
+  using namespace std;
+  typedef streambuf::pos_type pos_type;
+  typedef streambuf::off_type off_type;
+  pos_type bad = pos_type(off_type(-1));
+  pos_type p = 0;
+
+  // seekoff
+  p = in.pubseekoff(0, ios_base::beg, ios_base::in);
+  if (pass)
+    VERIFY( p != bad );
+
+  p = in.pubseekoff(0, ios_base::beg, ios_base::out); 
+  if (pass)
+    VERIFY( p != bad );
+
+  p = in.pubseekoff(0, ios_base::beg); 
+  if (pass)
+    VERIFY( p != bad );
+}
+
+const char name_01[] = "filebuf_virtuals-1.tst"; // file with data in it
+const char name_03[] = "filebuf_members-1.tst"; // empty file
+
+int main() 
+{
+  using namespace std;
+
+  filebuf in1;
+  in1.open(name_01, ios_base::in | ios_base::out);
+  filebuf in2;
+  filebuf in3;
+  in3.open(name_03, ios_base::in | ios_base::out);
+  test02(in1, true);
+  test02(in2, false);
+  test02(in3, true);
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-out.cc
new file mode 100644
index 000000000..08eac2933
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/3-out.cc
@@ -0,0 +1,63 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.7.1.3 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+
+void test02(std::filebuf& in, bool pass)
+{
+  bool test __attribute__((unused)) = true;
+  using namespace std;
+  typedef streambuf::pos_type pos_type;
+  typedef streambuf::off_type off_type;
+  pos_type bad = pos_type(off_type(-1));
+  pos_type p = 0;
+
+  // seekoff
+  p = in.pubseekoff(0, ios_base::beg, ios_base::in);
+  VERIFY( pass == (p != bad) );  // See libstdc++/12232
+
+  p = in.pubseekoff(0, ios_base::beg, ios_base::out); 
+  VERIFY( pass == (p != bad) );
+
+  p = in.pubseekoff(0, ios_base::beg); 
+  VERIFY( pass == (p != bad) );
+}
+
+const char name_01[] = "filebuf_virtuals-1.tst"; // file with data in it
+const char name_03[] = "filebuf_members-1.tst"; // empty file
+
+int main() 
+{
+  using namespace std;
+
+  filebuf out1;
+  out1.open(name_01, ios_base::out);
+  filebuf out2;
+  filebuf out3;
+  out3.open(name_03, ios_base::out);
+  test02(out1, true);
+  test02(out2, false);
+  test02(out3, true);
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/4.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/4.cc
new file mode 100644
index 000000000..fe21b3a88
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/4.cc
@@ -0,0 +1,93 @@
+// { dg-require-fileio "" }
+
+// Copyright (C) 2010 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+#include <fstream>
+#include <cstring>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;
+
+  typedef filebuf::pos_type pos_type;
+  const char name[] = "tmp_seekoff-4.tst";
+
+  const size_t size = 12;
+  char buf[size];
+  streamsize n;
+
+  filebuf fb;
+  fb.open(name, ios_base::in | ios_base::out | ios_base::trunc);
+
+  n = fb.sputn("abcd", 4);
+  VERIFY( n == 4 );
+
+  fb.pubseekoff(0, ios_base::beg);
+  n = fb.sgetn(buf, 3);
+  VERIFY( n == 3 );
+  VERIFY( !memcmp(buf, "abc", 3) );
+
+  // Check read => write without pubseekoff(0, ios_base::cur)
+
+  n = fb.sputn("ef", 2);
+  VERIFY( n == 2 );
+
+  fb.pubseekoff(0, ios_base::beg);
+
+  n = fb.sgetn(buf, size);
+  VERIFY( n == 5 );
+  VERIFY( !memcmp(buf, "abcef", 5) );
+
+  fb.pubseekoff(0, ios_base::beg);
+  n = fb.sputn("gh", 2);
+  VERIFY( n == 2 );
+  
+  // Check write => read without pubseekoff(0, ios_base::cur)
+
+  n = fb.sgetn( buf, 3 );
+  VERIFY( !memcmp(buf, "cef", 3) );
+
+  n = fb.sputn("ijkl", 4);
+  VERIFY( n == 4 );
+  
+  fb.pubseekoff(0, ios_base::beg);
+  n = fb.sgetn(buf, 2);
+  VERIFY( n == 2 );
+  VERIFY( !memcmp(buf, "gh", 2) );
+
+  fb.pubseekoff(0, ios_base::end);
+  n = fb.sputn("mno", 3);
+  VERIFY( n == 3 );
+
+  fb.pubseekoff(0, ios_base::beg);
+  n = fb.sgetn(buf, size);
+  VERIFY( n == 12 );
+  VERIFY( !memcmp(buf, "ghcefijklmno", 12) );
+
+  fb.close();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/45628-1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/45628-1.cc
new file mode 100644
index 000000000..a80a33876
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/45628-1.cc
@@ -0,0 +1,79 @@
+// Copyright (C) 2010 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+
+const char name_01[] = "tmp_seekoff_45628.tst";
+
+unsigned underflows, overflows;
+
+class my_filebuf
+: public std::filebuf
+{
+  virtual int_type
+  underflow()
+  {
+    ++underflows;
+    return std::filebuf::underflow();
+  }
+  virtual int_type
+  overflow(int_type c)
+  {
+    ++overflows;
+    return std::filebuf::overflow(c);
+  }
+};
+
+// libstdc++/45628
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  my_filebuf q;
+  q.open(name_01, std::ios_base::in | std::ios_base::out 
+	 | std::ios_base::trunc); 
+
+  q.sputc('a');
+  q.pubseekoff(0, std::ios_base::cur);
+  q.sputc('b');
+  q.pubseekoff(0, std::ios_base::cur);
+  q.sputc('c');
+  q.pubseekoff(0, std::ios_base::cur);
+
+  VERIFY( overflows <= 1 ); // only initial sputc allowed to overflow
+  q.pubseekoff(0, std::ios_base::beg);
+
+  q.sbumpc();
+  VERIFY( underflows == 1 );
+
+  q.pubseekoff(0, std::ios_base::cur);
+  q.sbumpc();
+  q.pubseekoff(0, std::ios_base::cur);
+  q.sbumpc();
+  q.pubseekoff(0, std::ios_base::cur);
+
+  VERIFY( underflows == 1 );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}