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.

24 files changed, 2039 insertions, 0 deletions

diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/10132-3.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/10132-3.cc
new file mode 100644
index 000000000..34d437925
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/10132-3.cc
@@ -0,0 +1,54 @@
+// 2003-04-24 bkoz
+
+// Copyright (C) 2003, 2004, 2005, 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/>.
+
+// 27.8.1.1 - Template class basic_filebuf 
+// NB: This file is for testing basic_filebuf with NO OTHER INCLUDES.
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_character.h>
+
+// libstdc++/10132, add on
+void test07()
+{
+  bool test __attribute__((unused)) = true;
+  typedef std::basic_filebuf<__gnu_test::pod_ushort> gnu_filebuf;
+  
+  try
+    { 
+      // Need codecvt facet for width argument in seekpos.
+      gnu_filebuf obj;
+      obj.pubseekpos(0);
+    }
+  catch(std::exception& obj)
+    { 
+      test = false; 
+      VERIFY( test );
+    }
+}
+
+int main() 
+{
+  test07();
+  return 0;
+}
+
+
+
+// more surf!!!
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-1.cc
new file mode 100644
index 000000000..ffe5aa726
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-1.cc
@@ -0,0 +1,67 @@
+// Copyright (C) 2003, 2005, 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>
+#include <testsuite_character.h>
+
+// libstdc++/12790
+void test01()
+{
+  using namespace std;
+  using __gnu_test::pod_uchar;
+  typedef basic_filebuf<pod_uchar>::traits_type traits_type;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  locale loc(locale::classic(),
+	     new codecvt<traits_type::char_type, char,
+	     traits_type::state_type>);
+
+  basic_filebuf<pod_uchar> fb;
+  fb.pubsetbuf(0, 0);
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::in | ios_base::out | ios_base::trunc);
+  traits_type::pos_type pos = fb.pubseekoff(0, ios_base::cur);
+  fb.sputc(pod_uchar::from<char>('a'));
+  fb.sputc(pod_uchar::from<char>(0xff));
+  fb.sputc(pod_uchar::from<char>(0));
+  fb.sputc(pod_uchar::from<char>(0));
+
+  // Check that seekpos restores the state correctly
+  fb.pubseekpos(pos);
+
+  traits_type::int_type c = fb.sbumpc();
+  VERIFY( c != traits_type::eof() );
+  VERIFY( traits_type::eq(traits_type::to_char_type(c),
+			  pod_uchar::from<char>('a')) );
+
+  fb.close();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-2.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-2.cc
new file mode 100644
index 000000000..8b7050965
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-2.cc
@@ -0,0 +1,82 @@
+// Copyright (C) 2003, 2005, 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>
+#include <testsuite_character.h>
+
+// libstdc++/12790
+void test01()
+{
+  using namespace std;
+  using __gnu_test::pod_uchar;
+  typedef basic_filebuf<pod_uchar>::traits_type traits_type;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  locale loc(locale::classic(),
+	     new codecvt<traits_type::char_type, char,
+	     traits_type::state_type>);
+
+  basic_filebuf<pod_uchar> fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out | ios_base::trunc);
+  fb.sputc(pod_uchar::from<char>('b'));
+  fb.sputc(pod_uchar::from<char>(0xff));
+  fb.sputc(pod_uchar::from<char>('a'));
+  fb.sputc(pod_uchar::from<char>(0xfc));
+  fb.sputc(pod_uchar::from<char>(0));
+  fb.sputc(pod_uchar::from<char>(0));
+
+  fb.close();
+  fb.open(name, ios_base::in);
+
+  fb.sbumpc();
+  fb.sbumpc();
+  traits_type::pos_type pos1 = fb.pubseekoff(0, ios_base::cur);
+  fb.sbumpc();
+  fb.sbumpc();
+
+  // Check that seekpos returns the correct state
+  traits_type::pos_type pos2 = fb.pubseekpos(pos1);
+  traits_type::int_type c = fb.sbumpc();
+  VERIFY( c != traits_type::eof() );
+  VERIFY( traits_type::eq(traits_type::to_char_type(c),
+			  pod_uchar::from<char>('a')) );
+  fb.sbumpc();
+
+  fb.pubseekpos(pos2);
+  c = fb.sbumpc();
+  VERIFY( c != traits_type::eof() );
+  VERIFY( traits_type::eq(traits_type::to_char_type(c),
+			  pod_uchar::from<char>('a')) );
+
+  fb.close();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-3.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-3.cc
new file mode 100644
index 000000000..79337d381
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/12790-3.cc
@@ -0,0 +1,80 @@
+// Copyright (C) 2003, 2005, 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>
+#include <testsuite_character.h>
+
+// libstdc++/12790
+void test01()
+{
+  using namespace std;
+  using __gnu_test::pod_uchar;
+  typedef basic_filebuf<pod_uchar>::traits_type traits_type;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  locale loc(locale::classic(),
+	     new codecvt<traits_type::char_type, char,
+	     traits_type::state_type>);
+
+  basic_filebuf<pod_uchar> fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::in | ios_base::out | ios_base::trunc);
+  fb.sputc(pod_uchar::from<char>('b'));
+  fb.sputc(pod_uchar::from<char>(0xff));
+  fb.sputc(pod_uchar::from<char>('c'));
+  fb.sputc(pod_uchar::from<char>(0xff));
+
+  fb.pubseekoff(0, ios_base::beg);
+  fb.sbumpc();
+  fb.sbumpc();
+  traits_type::pos_type pos = fb.pubseekoff(0, ios_base::cur);
+  fb.sbumpc();
+  fb.sbumpc();
+
+  // Check that seekoff sets the current state for output
+  fb.pubseekpos(pos);
+
+  fb.sputc(pod_uchar::from<char>('a'));
+  fb.sputc(pod_uchar::from<char>(0));
+  fb.sputc(pod_uchar::from<char>(0));
+  fb.sputc(pod_uchar::from<char>(0));
+  fb.sputc(pod_uchar::from<char>(0));
+  
+  fb.pubseekpos(pos);
+
+  traits_type::int_type c = fb.sbumpc();
+  VERIFY( c != traits_type::eof() );
+  VERIFY( traits_type::eq(traits_type::to_char_type(c),
+			  pod_uchar::from<char>('a')) );
+
+  fb.close();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-in.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-in.cc
new file mode 100644
index 000000000..da5a80b4b
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-in.cc
@@ -0,0 +1,103 @@
+// 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/>.
+
+// 27.8.1.4 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[] = "seekpos.txt"; // file with data in it
+
+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;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  pos_type pt_3;
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekpos
+  // pubseekpos(pos_type sp, ios_base::openmode)
+  // alters the stream position to sp
+
+  // in 
+  {
+    constraint_filebuf fb;
+    fb.open(name_01, ios_base::in);
+    VERIFY( !fb.write_position() );
+
+    // beg
+    pt_1 = fb.pubseekoff(78, ios_base::beg);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == 't' );
+
+    // cur
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c2 = fb.sputc('\n'); //test current out pointer
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c3 = fb.sgetc();
+    fb.pubsync(); //resets pointers
+    pt_2 = fb.pubseekpos(pt_1);
+    off_2 = off_type(pt_2);
+    VERIFY( off_1 == off_2 );
+    c3 = fb.snextc(); //current in pointer +1
+    VERIFY( c2 == traits_type::eof() );
+    VERIFY( c2 != c3 );
+
+    // end
+    pt_1 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > off_2 );
+    fb.sputn("\nof the wonderful things he does!!\nok", 37);
+    fb.pubsync();
+    VERIFY( !fb.write_position() );
+    fb.close();
+    VERIFY( !fb.is_open() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-io.cc
new file mode 100644
index 000000000..c90de5e31
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-io.cc
@@ -0,0 +1,103 @@
+// 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/>.
+
+// 27.8.1.4 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[] = "seekpos-1io.tst"; // file with data in it
+
+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;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  pos_type pt_3;
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekpos
+  // pubseekpos(pos_type sp, ios_base::openmode)
+  // alters the stream position to sp
+
+  // in | out
+  {
+    constraint_filebuf fb;
+    fb.open(name_01, ios_base::out | ios_base::in);
+    VERIFY( !fb.write_position() );
+    VERIFY( !fb.read_position() );
+
+    // beg
+    pt_1 = fb.pubseekoff(78, ios_base::beg);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == 't' );
+
+    // cur
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c2 = fb.sputc('\n'); //test current out pointer
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c3 = fb.sgetc();
+    fb.pubsync(); //resets pointers
+    pt_2 = fb.pubseekpos(pt_1);
+    off_2 = off_type(pt_2);
+    VERIFY( off_1 == off_2 );
+    c3 = fb.snextc(); //current in pointer +1
+    VERIFY( c2 == c3 );
+
+    // end
+    pt_1 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > off_2 );
+    fb.sputn("\nof the wonderful things he does!!\nok", 37);
+    fb.pubsync();
+    VERIFY( fb.write_position() );
+    VERIFY( !fb.read_position() );
+    fb.close();
+    VERIFY( !fb.is_open() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-out.cc
new file mode 100644
index 000000000..0b596a451
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-out.cc
@@ -0,0 +1,105 @@
+// 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/>.
+
+// 27.8.1.4 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[] = "seekpos-1out.tst"; // file with data in it
+
+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;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  pos_type pt_3;
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekpos
+  // pubseekpos(pos_type sp, ios_base::openmode)
+  // alters the stream position to sp
+
+  // out
+  {
+    constraint_filebuf fb;
+    fb.open(name_01, ios_base::out);
+    VERIFY( !fb.write_position() );
+    VERIFY( !fb.read_position() );
+
+    // beg
+    pt_1 = fb.pubseekoff(78, ios_base::beg);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == traits_type::eof() );
+
+    // cur
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c2 = fb.sputc('\n'); //test current out pointer
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c3 = fb.sgetc();
+    fb.pubsync(); //resets pointers
+    pt_2 = fb.pubseekpos(pt_1);
+    off_2 = off_type(pt_2);
+    VERIFY( off_1 == off_2 );
+    c3 = fb.snextc(); //current in pointer +1
+    VERIFY( c2 != c3 );
+    VERIFY( c3 == traits_type::eof() );
+
+    // end
+    pt_1 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > off_2 );
+    fb.sputn("\nof the wonderful things he does!!\nok", 37);
+    fb.pubsync();
+    VERIFY( fb.write_position() );
+    VERIFY( !fb.read_position() );
+    fb.close();
+    VERIFY( !fb.is_open() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-1.cc
new file mode 100644
index 000000000..1a024941f
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-1.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::seekpos() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  filebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+  fb.sputc('a');
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekpos(pos);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-2.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-2.cc
new file mode 100644
index 000000000..b0085e29e
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-2.cc
@@ -0,0 +1,82 @@
+// 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::seekpos() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_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);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+  fb.sputc('a');
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekpos(pos);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-3.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-3.cc
new file mode 100644
index 000000000..0eb3ecf80
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-3.cc
@@ -0,0 +1,79 @@
+// 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 <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::seekpos() should call codecvt::unshift(),
+// but only if writing
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  filebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekpos(pos);
+  VERIFY( !cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-4.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-4.cc
new file mode 100644
index 000000000..506482bd6
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/12790-4.cc
@@ -0,0 +1,82 @@
+// 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::seekpos() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  filebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+  fb.sputc('a');
+  fb.pubsync(); // Does not call unshift()
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekpos(pos);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-in.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-in.cc
new file mode 100644
index 000000000..782fb6bb8
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-in.cc
@@ -0,0 +1,104 @@
+// 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/>.
+
+// 27.8.1.4 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[] = "seekpos.txt"; // file with data in it
+
+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;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  pos_type pt_3;
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekpos
+  // pubseekpos(pos_type sp, ios_base::openmode)
+  // alters the stream position to sp
+
+  // in 
+  {
+    constraint_filebuf fb;
+    fb.pubsetbuf(0, 0);
+    fb.open(name_01, ios_base::in);
+    VERIFY( fb.unbuffered() );
+
+    // beg
+    pt_1 = fb.pubseekoff(78, ios_base::beg);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == 't' );
+
+    // cur
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c2 = fb.sputc('\n'); //test current out pointer
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c3 = fb.sgetc();
+    fb.pubsync(); //resets pointers
+    pt_2 = fb.pubseekpos(pt_1);
+    off_2 = off_type(pt_2);
+    VERIFY( off_1 == off_2 );
+    c3 = fb.snextc(); //current in pointer +1
+    VERIFY( c2 == traits_type::eof() );
+    VERIFY( c2 != c3 );
+
+    // end
+    pt_1 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > off_2 );
+    fb.sputn("\nof the wonderful things he does!!\nok", 37);
+    fb.pubsync();
+    VERIFY( fb.unbuffered() );
+    fb.close();
+    VERIFY( !fb.is_open() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-io.cc
new file mode 100644
index 000000000..4916d6059
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-io.cc
@@ -0,0 +1,102 @@
+// 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/>.
+
+// 27.8.1.4 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[] = "seekpos-2io.tst"; // file with data in it
+
+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;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  pos_type pt_3;
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekpos
+  // pubseekpos(pos_type sp, ios_base::openmode)
+  // alters the stream position to sp
+
+  // in | out
+  {
+    constraint_filebuf fb;
+    fb.pubsetbuf(0, 0);
+    fb.open(name_01, ios_base::out | ios_base::in);
+    VERIFY( fb.unbuffered() );
+
+    // beg
+    pt_1 = fb.pubseekoff(78, ios_base::beg);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == 't' );
+
+    // cur
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c2 = fb.sputc('\n'); //test current out pointer
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c3 = fb.sgetc();
+    fb.pubsync(); //resets pointers
+    pt_2 = fb.pubseekpos(pt_1);
+    off_2 = off_type(pt_2);
+    VERIFY( off_1 == off_2 );
+    c3 = fb.snextc(); //current in pointer +1
+    VERIFY( c2 == c3 );
+
+    // end
+    pt_1 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > off_2 );
+    fb.sputn("\nof the wonderful things he does!!\nok", 37);
+    fb.pubsync();
+    VERIFY( fb.unbuffered() );
+    fb.close();
+    VERIFY( !fb.is_open() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-out.cc
new file mode 100644
index 000000000..9031bca6c
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/2-out.cc
@@ -0,0 +1,104 @@
+// 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/>.
+
+// 27.8.1.4 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[] = "seekpos-2out.tst"; // file with data in it
+
+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;
+
+  int_type c1;
+  int_type c2;
+  int_type c3;
+
+  pos_type pt_1(off_type(-1));
+  pos_type pt_2(off_type(0));
+  pos_type pt_3;
+  off_type off_1 = 0;
+  off_type off_2 = 0;
+
+  // seekpos
+  // pubseekpos(pos_type sp, ios_base::openmode)
+  // alters the stream position to sp
+
+  // out
+  {
+    constraint_filebuf fb;
+    fb.pubsetbuf(0, 0);
+    fb.open(name_01, ios_base::out);
+    VERIFY( fb.unbuffered() );
+
+    // beg
+    pt_1 = fb.pubseekoff(78, ios_base::beg);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > 0 );
+    c1 = fb.snextc(); //current in pointer +1
+    VERIFY( c1 == traits_type::eof() );
+
+    // cur
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c2 = fb.sputc('\n'); //test current out pointer
+    pt_3 = fb.pubseekoff(0, ios_base::cur);
+    fb.pubseekpos(pt_3);
+    c3 = fb.sgetc();
+    fb.pubsync(); //resets pointers
+    pt_2 = fb.pubseekpos(pt_1);
+    off_2 = off_type(pt_2);
+    VERIFY( off_1 == off_2 );
+    c3 = fb.snextc(); //current in pointer +1
+    VERIFY( c2 != c3 );
+    VERIFY( c3 == traits_type::eof() );
+
+    // end
+    pt_1 = fb.pubseekoff(0, ios_base::end);
+    off_1 = off_type(pt_1);
+    VERIFY( off_1 > off_2 );
+    fb.sputn("\nof the wonderful things he does!!\nok", 37);
+    fb.pubsync();
+    VERIFY( fb.unbuffered() );
+    fb.close();
+    VERIFY( !fb.is_open() );
+  }
+}
+
+int main() 
+{
+  test05();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/3-in.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/3-in.cc
new file mode 100644
index 000000000..278d39e72
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/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;
+
+  // seekpos
+  p = in.pubseekpos(0, ios_base::in);
+  VERIFY( pass == (p != bad) );
+
+  p = in.pubseekpos(0, ios_base::out);
+  VERIFY( pass == (p != bad) );  // See libstdc++/12232
+
+  p = in.pubseekpos(0); 
+  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/seekpos/char/3-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/3-io.cc
new file mode 100644
index 000000000..3f37a266a
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/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;
+
+  // seekpos
+  p = in.pubseekpos(0, ios_base::in);
+  if (pass)
+    VERIFY( p != bad );
+
+  p = in.pubseekpos(0, ios_base::out); 
+  if (pass)
+    VERIFY( p != bad );
+
+  p = in.pubseekpos(0); 
+  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/seekpos/char/3-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/3-out.cc
new file mode 100644
index 000000000..07bdc0cae
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/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;
+
+  // seekpos
+  p = in.pubseekpos(0, ios_base::in);
+  VERIFY( pass == (p != bad) );  // See libstdc++/12232
+
+  p = in.pubseekpos(0, ios_base::out); 
+  VERIFY( pass == (p != bad) );
+
+  p = in.pubseekpos(0);
+  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/seekpos/wchar_t/1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/1.cc
new file mode 100644
index 000000000..320938319
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/1.cc
@@ -0,0 +1,51 @@
+// Copyright (C) 2003, 2004, 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 <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;
+
+  const char* name = "tmp_seekpos_1";
+
+  wfilebuf fb;
+
+  fb.open(name, ios_base::out);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+  fb.sputc(0xf001);
+
+  try
+    {
+      fb.pubseekpos(pos);
+      VERIFY( false );
+    }
+  catch (std::exception&)
+    {
+    }
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-1.cc
new file mode 100644
index 000000000..55325875a
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-1.cc
@@ -0,0 +1,79 @@
+// 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 <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<wchar_t, 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::seekpos() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  wfilebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+  fb.sputc(L'a');
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekpos(pos);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-2.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-2.cc
new file mode 100644
index 000000000..e939050a4
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-2.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
+
+#include <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<wchar_t, 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::seekpos() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  wfilebuf fb;
+  fb.pubsetbuf(0, 0);
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+  fb.sputc(L'a');
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekpos(pos);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-3.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-3.cc
new file mode 100644
index 000000000..a1afdcad2
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-3.cc
@@ -0,0 +1,79 @@
+// 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 <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<wchar_t, 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::seekpos() should call codecvt::unshift(),
+// but only if writing
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  wfilebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekpos(pos);
+  VERIFY( !cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-4.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-4.cc
new file mode 100644
index 000000000..57a9a3c02
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/12790-4.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
+
+#include <locale>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<wchar_t, 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::seekpos() should call codecvt::unshift()
+void test01()
+{
+  using namespace std;
+
+  bool test __attribute__((unused)) = true;
+  const char* name = "tmp_seekpos_12790";
+
+  Cvt* cvt = new Cvt;
+  locale loc(locale::classic(), cvt);
+
+  wfilebuf fb;
+  fb.pubimbue(loc);
+
+  fb.open(name, ios_base::out);
+  streampos pos = fb.pubseekoff(0, ios_base::beg);
+  fb.sputc(L'a');
+  fb.pubsync(); // Does not call unshift()
+
+  VERIFY( !cvt->unshift_called );
+  fb.pubseekpos(pos);
+  VERIFY( cvt->unshift_called );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/9874.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/9874.cc
new file mode 100644
index 000000000..e011f875d
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/9874.cc
@@ -0,0 +1,139 @@
+// { dg-require-namedlocale "se_NO.UTF-8" }
+
+// 2003-10-07  Petur Runolfsson  <peturr02@ru.is>
+//
+// Copyright (C) 2003, 2004, 2005, 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 <locale>
+#include <vector>
+#include <utility>
+#include <testsuite_hooks.h>
+
+// libstdc++/9874
+void test01()
+{
+  using namespace std;
+  typedef wfilebuf::pos_type pos_type;
+  typedef wfilebuf::int_type int_type;
+  typedef vector<pair<pos_type, size_t> > vec_type;
+
+  bool test __attribute__((unused)) = true;
+  const char name[] = "tmp_seekpos-9874.tst";
+  const int_type eof = wfilebuf::traits_type::eof();
+
+  const char cstr[] =
+    "\x1\x2\x3\x4\x5\x6\x7\x8\x9\xa\xb\xc\xd\xe\xf\x10\x11\x12\x13"
+    "\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20!\"#$%&"
+    "'()*+,-./0123456789:;<=>?@}~\x7f\xc2\x80\xc2\x81\xc2\x82\xc2"
+    "\x83\xc2\x84\xc2\x85\xc2\x86\xc2\x87\xc2\x88\xc2\x89\xc2\x8a"
+    "\xc2\x8b\xc2\x8c\xc2\x8d\xc2\x8e\xc2\x8f\xc2\x90\xc2\x91\xc2"
+    "\x92\xc2\x93\xc2\x94\xc2\x95\xc2\x96\xc2\x97\xc2\x98\xc2\x99"
+    "\xc2\x9a\xc2\x9b\xc2\x9c\xc3\xba\xc3\xbb\xc3\xbc\xc3\xbd\xc3"
+    "\xbe\xc3\xbf\xc4\x80\xc4\x81\xc4\x82\xc4\x83\xc4\x84\xc4\x85"
+    "\xc4\x86\xc4\x87\xc4\x88\xc4\x89\xc4\x8a\xc4\x8b\xc4\x8c\xc4"
+    "\x8d\xc4\x8e\xc4\x8f\xc4\x90\xc4\x91\xc4\x92\xc4\x93\xc4\x94"
+    "\xc4\x95\xc4\x96\xc4\x97\xc4\x98\xc4\x99\xdf\xb8\xdf\xb9\xdf"
+    "\xba\xdf\xbb\xdf\xbc\xdf\xbd\xdf\xbe\xdf\xbf\xe0\xa0\x80\xe0"
+    "\xa0\x81\xe0\xa0\x82\xe0\xa0\x83\xe0\xa0\x84\xe0\xa0\x85\xe0"
+    "\xa0\x86\xe0\xa0\x87\xe0\xa0\x88\xe0\xa0\x89\xe0\xa0\x8a\xe0"
+    "\xa0\x8b\xe0\xa0\x8c\xe0\xa0\x8d\xe0\xa0\x8e\xe0\xa0\x8f\xe0"
+    "\xa0\x90\xe0\xa0\x91\xe0\xa0\x92\xe0\xa0\x93\xe0\xa0\x94\xe0"
+    "\xa0\x95\xe0\xa0\x96\xe0\xa0\x97\x1\x2\x4\x8\x10\x20@\xc2\x80"
+    "\xc4\x80\xc8\x80\xd0\x80\xe0\xa0\x80\xe1\x80\x80\xe2\x80\x80"
+    "\xe4\x80\x80\xe8\x80\x80\xf0\x90\x80\x80\xf0\xa0\x80\x80\xf1"
+    "\x80\x80\x80\xf2\x80\x80\x80\xf4\x80\x80\x80\xf8\x88\x80\x80"
+    "\x80\xf8\x90\x80\x80\x80\xf8\xa0\x80\x80\x80\xf9\x80\x80\x80"
+    "\x80\xfa\x80\x80\x80\x80\xfc\x84\x80\x80\x80\x80\xfc\x88\x80"
+    "\x80\x80\x80\xfc\x90\x80\x80\x80\x80\xfc\xa0\x80\x80\x80\x80"
+    "\xfd\x80\x80\x80\x80\x80";
+
+  const wchar_t wstr[] = {
+    0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, 0xb, 0xc,
+    0xd, 0xe, 0xf, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, L'!',
+    L'"', L'#', L'$', L'%', L'&', L'\'', L'(', L')', L'*', L'+',
+    L',', L'-', L'.', L'/', L'0', L'1', L'2', L'3', L'4', L'5',
+    L'6', L'7', L'8', L'9', L':', L';', L'<', L'=', L'>', L'?',
+    L'@', L'}', L'~', 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85,
+    0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99,
+    0x9a, 0x9b, 0x9c, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, 0x100,
+    0x101, 0x102, 0x103, 0x104, 0x105, 0x106, 0x107, 0x108, 0x109,
+    0x10a, 0x10b, 0x10c, 0x10d, 0x10e, 0x10f, 0x110, 0x111, 0x112,
+    0x113, 0x114, 0x115, 0x116, 0x117, 0x118, 0x119, 0x7f8, 0x7f9,
+    0x7fa, 0x7fb, 0x7fc, 0x7fd, 0x7fe, 0x7ff, 0x800, 0x801, 0x802,
+    0x803, 0x804, 0x805, 0x806, 0x807, 0x808, 0x809, 0x80a, 0x80b,
+    0x80c, 0x80d, 0x80e, 0x80f, 0x810, 0x811, 0x812, 0x813, 0x814,
+    0x815, 0x816, 0x817, 0x1, 0x2, 0x4, 0x8, 0x10, 0x20, L'@',
+    0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000,
+    0x10000, 0x20000, 0x40000, 0x80000, 0x100000, 0x200000, 0x400000,
+    0x800000, 0x1000000, 0x2000000, 0x4000000, 0x8000000, 0x10000000,
+    0x20000000, 0x40000000, 0x0
+  };
+
+  const size_t clen = sizeof(cstr) / sizeof(cstr[0]);
+  const size_t wlen = sizeof(wstr) / sizeof(wstr[0]);
+
+  const int loops = 2 * BUFSIZ / wlen;
+  locale loc = locale("se_NO.UTF-8");
+
+  FILE* file = fopen(name, "w");
+  for (int i = 0; i < loops; ++i)
+    fwrite(cstr, 1, clen, file);
+  fclose(file);
+
+  wfilebuf fb;
+  fb.pubimbue(loc);
+  fb.open(name, ios_base::in);
+
+  vec_type vec;
+
+  const size_t limit = wlen * loops;
+  for (size_t index = 0; index < limit; ++index)
+    {
+      // Call seekoff at pseudo-random intervals.
+      if (index % 5 == 0 || index % 7 == 0)
+	{
+	  pos_type p1 = fb.pubseekoff(0, ios_base::cur);
+	  VERIFY( p1 != pos_type(-1) );
+	  vec.push_back(make_pair(p1, index));
+	}
+      int_type c1 = fb.sbumpc();
+      VERIFY( c1 != eof );
+    }
+
+  for (vec_type::iterator it = vec.begin(); it != vec.end(); ++it)
+    {
+      pos_type p2 = fb.pubseekpos(it->first);
+      VERIFY( p2 == it->first );
+      int_type c2 = fb.sbumpc();
+      VERIFY( c2 != eof );
+      VERIFY( static_cast<wchar_t>(c2) == wstr[it->second % wlen] );
+    }
+
+  fb.close();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/9875_seekpos.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/9875_seekpos.cc
new file mode 100644
index 000000000..501ce1fda
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/wchar_t/9875_seekpos.cc
@@ -0,0 +1,111 @@
+// 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 <locale>
+#include <algorithm>
+#include <cstring>
+#include <testsuite_hooks.h>
+
+class Cvt : public std::codecvt<wchar_t, char, mbstate_t>
+{
+protected:
+  virtual std::codecvt_base::result
+  do_out(std::mbstate_t&, const wchar_t* from, const wchar_t* from_end,
+	 const wchar_t*& from_next, char* to, char* to_end,
+	 char*& to_next) const
+  {
+    std::size_t from_len = from_end - from;
+    std::size_t to_len = (to_end - to) / sizeof(wchar_t);
+    std::size_t len = std::min(from_len, to_len);
+    std::memcpy(to, from, len * sizeof(wchar_t));
+    from_next = from + len;
+    to_next = to + len * sizeof(wchar_t);
+    return from_next == from_end ? std::codecvt_base::ok :
+           std::codecvt_base::partial;
+  }
+
+  virtual std::codecvt_base::result
+  do_in(std::mbstate_t&, const char* from, const char* from_end,
+	const char*& from_next, wchar_t* to, wchar_t* to_end,
+	wchar_t*& to_next) const
+  {
+    std::size_t from_len =
+      (from_end - from) / sizeof(wchar_t);
+    std::size_t to_len = to_end - to;
+    std::size_t len = std::min(from_len, to_len);
+    std::memcpy(to, from, len * sizeof(wchar_t));
+    from_next = from + len * sizeof(wchar_t);
+    to_next = to + len;
+    return from_next == from_end ? std::codecvt_base::ok :
+           std::codecvt_base::partial;
+  }
+  
+  virtual std::codecvt_base::result
+  do_unshift(std::mbstate_t&, char*, char*, char*&) const
+  { return std::codecvt_base::noconv; }
+  
+  virtual int do_encoding() const throw() { return sizeof(wchar_t); }
+  virtual bool do_always_noconv() const throw() { return false; }
+  
+  virtual int
+  do_length(std::mbstate_t&, const char* from, const char* end,
+	    std::size_t max)
+  {
+    std::size_t len = (end - from) / sizeof(wchar_t);
+    return std::min(len, max) * sizeof(wchar_t);
+  }
+  
+  virtual int do_max_length() const throw() { return sizeof(wchar_t); }
+};
+
+void test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;
+
+  // seekpos
+  wfilebuf fb;
+  fb.pubimbue(locale(locale::classic(), new Cvt));
+  fb.open("tmp_9875_seekpos", ios_base::out | ios_base::in | ios_base::trunc);
+  fb.sputn(L"0123456789", 10);
+  
+  streampos p1 = fb.pubseekoff(0, ios_base::cur);
+  VERIFY( p1 != streampos(-1) );
+  fb.sputc(L'a');
+  
+  streampos p2 = fb.pubseekpos(p1);
+  VERIFY( p2 != streampos(-1) );
+  VERIFY( p2 == p1 );
+  VERIFY( fb.sgetc() == L'a' );
+  
+  fb.pubseekoff(0, ios_base::beg);
+  wchar_t buf[11];
+  streamsize s1 = fb.sgetn(buf, 11);
+  VERIFY( s1 == 11 );
+  VERIFY( !wmemcmp(buf, L"0123456789a", 11) );
+  
+  fb.close();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}