1.cc: Split and fix for missing seeks between gets and puts into...

2003-06-16  Paolo Carlini  <pcarlini@unitus.it>

        * testsuite/27_io/basic_filebuf/sungetc/char/1.cc: Split and
        fix for missing seeks between gets and puts into...
	* testsuite/27_io/basic_filebuf/sungetc/char/1-in.cc: New.
        * testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc: New.
        * testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc: New.
        * testsuite/27_io/basic_filebuf/sungetc/char/2-in.cc: New.
	* testsuite/27_io/basic_filebuf/sungetc/char/2-io.cc: New.
	* testsuite/27_io/basic_filebuf/sungetc/char/2-out.cc: New.

From-SVN: r68021

8 files changed, 460 insertions, 178 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index b1f91a4..1620cf4 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,14 @@
+2003-06-16  Paolo Carlini  <pcarlini@unitus.it>
+
+	* testsuite/27_io/basic_filebuf/sungetc/char/1.cc: Split and
+        fix for missing seeks between gets and puts into...
+	* testsuite/27_io/basic_filebuf/sungetc/char/1-in.cc: New.
+	* testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc: New.
+	* testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc: New.
+	* testsuite/27_io/basic_filebuf/sungetc/char/2-in.cc: New.
+	* testsuite/27_io/basic_filebuf/sungetc/char/2-io.cc: New.
+	* testsuite/27_io/basic_filebuf/sungetc/char/2-out.cc: New.
+		
 2003-06-15  Richard Henderson  <rth@redhat.com>
 
 	* config/linker-map.gnu: Export virtual function thunks for
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-in.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-in.cc
new file mode 100644
index 0000000..bf753ca
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-in.cc
@@ -0,0 +1,71 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003 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 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.8.1.4 Overridden virtual functions
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "sgetc.txt"; // file with data in it
+
+// Test overloaded virtual functions.
+void test01() 
+{
+  using namespace std;
+  using namespace __gnu_cxx_test;
+  typedef std::filebuf::int_type 	int_type;
+  typedef filebuf::traits_type 		traits_type;
+
+  bool 					test = true;
+  int_type 			        c1, c2, c3;
+
+  // int_type sungetc()
+  // if in_cur not avail, return pbackfail(), else decrement and
+  // return to_int_type(*gptr())
+
+  // in
+  {
+    constraint_filebuf fb_01;
+    fb_01.open(name_01, ios::in);
+    VERIFY( !fb_01.write_position() );
+    c1 = fb_01.sbumpc();
+    VERIFY( c1 == '/' );
+    c2 = fb_01.sungetc();
+    VERIFY( c2 == c1 );
+    c3 = fb_01.sgetc();
+    VERIFY( c3 == c2 );
+    fb_01.pubseekoff(2, ios_base::beg, ios_base::in);
+    c1 = fb_01.sgetc();
+    VERIFY( c1 == ' ' );
+    c2 = fb_01.sungetc();
+    VERIFY( c2 == traits_type::not_eof(traits_type::eof()) );
+    VERIFY( !fb_01.write_position() );
+  }
+}
+
+main() 
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc
new file mode 100644
index 0000000..38819b6
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-io.cc
@@ -0,0 +1,83 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003 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 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.8.1.4 Overridden virtual functions
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "tmp_sungetc_1io.tst"; // empty file, need to create
+
+void test01() 
+{
+  using namespace std;
+  using namespace __gnu_cxx_test;
+
+  typedef filebuf::int_type 	int_type;
+  typedef filebuf::traits_type 	traits_type;
+  typedef size_t 		size_type;
+
+  bool 				test = true;
+  streamsize 			strmsz_1, strmsz_2;
+  int_type 			c1, c2, c3;
+
+  // int_type sungetc()
+  // if in_cur not avail, return pbackfail(), else decrement and
+  // return to_int_type(*gptr())
+
+  // in | out
+  {
+    constraint_filebuf fb_01; 
+    fb_01.open(name_01, ios_base::out | ios_base::in | ios_base::trunc);
+    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.read_position() );
+    fb_01.sputc('u');
+    fb_01.sputc('v');
+    fb_01.pubseekoff(-1, std::ios_base::end);
+    c3 = fb_01.sbumpc();
+    strmsz_1 = fb_01.in_avail();
+    c2 = fb_01.sungetc(); 
+    strmsz_2 = fb_01.in_avail();
+    VERIFY( c2 == 'v' ); //  VERIFY( c2 != traits_type::eof() );
+    VERIFY( strmsz_1 + 1 == strmsz_2 );
+    //test for _in_cur == _in_end
+    fb_01.pubseekoff(0, std::ios_base::end);
+    strmsz_1 = fb_01.in_avail(); // -1 cuz at the end
+    c1 = fb_01.sgetc(); 
+    c2 = fb_01.sungetc();
+    strmsz_2 = fb_01.in_avail(); // 1
+    c3 = fb_01.sgetc();
+    VERIFY( c1 != c2 );
+    VERIFY( strmsz_2 != strmsz_1 );
+    VERIFY( strmsz_2 == 1 );
+    VERIFY( fb_01.write_position() );
+    VERIFY( fb_01.read_position() );
+  }
+}
+
+main() 
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc
new file mode 100644
index 0000000..f7d7831
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1-out.cc
@@ -0,0 +1,70 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003 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 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.8.1.4 Overridden virtual functions
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "tmp_sungetc_1out.tst"; // empty file, need to create
+
+// Test overloaded virtual functions.
+void test01() 
+{
+  using namespace std;
+  using namespace __gnu_cxx_test;
+  typedef std::filebuf::int_type 	int_type;
+  typedef filebuf::traits_type 		traits_type;
+
+  bool 					test = true;
+  int_type 			c1, c2, c3;
+
+  // int_type sungetc()
+  // if in_cur not avail, return pbackfail(), else decrement and
+  // return to_int_type(*gptr())
+
+  // out
+  {
+    constraint_filebuf fb_01; // out
+    fb_01.open(name_01, ios::out | ios::trunc);    
+    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.read_position() );
+    c1 = fb_01.sgetc();
+    VERIFY( c1 == traits_type::eof() );
+    c2 = fb_01.sungetc();
+    VERIFY( c2 == traits_type::eof() );
+    fb_01.sbumpc();
+    c1 = fb_01.sbumpc();
+    c2 = fb_01.sungetc();
+    VERIFY( c1 == c2 );
+    VERIFY( fb_01.write_position() );
+    VERIFY( !fb_01.read_position() );
+  }
+}
+
+main() 
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1.cc
deleted file mode 100644
index 201217e..0000000
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/1.cc
+++ /dev/null
@@ -1,178 +0,0 @@
-// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
-
-// Copyright (C) 2001, 2002, 2003 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 2, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING.  If not, write to the Free
-// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
-// USA.
-
-// 27.8.1.4 Overridden virtual functions
-
-#include <fstream>
-#include <testsuite_hooks.h>
-
-// @require@ %-*.tst %-*.txt
-// @diff@ %-*.tst %*.txt
-
-// NB: This test assumes that _M_buf_size == 40, and not the usual
-// buffer_size length of BUFSIZ (8192), so that overflow/underflow can be
-// simulated a bit more readily.
-// NRB (Nota Really Bene): setting it to 40 breaks the test, as intended.
-const int buffer_size = 8192;
-//const int buffer_size = 40;
-
-const char name_01[] = "filebuf_virtuals-1.txt"; // file with data in it
-const char name_02[] = "filebuf_virtuals-2.txt"; // empty file, need to create
-const char name_03[] = "filebuf_virtuals-3.txt"; // empty file, need to create
-
-class derived_filebuf: public std::filebuf
-{
- public:
-  void
-  set_size(int_type __size) { _M_buf_size = __size; }
-};
-
-derived_filebuf fb_01; // in 
-derived_filebuf fb_02; // out
-derived_filebuf fb_03; // in | out
-
-// Initialize filebufs to be the same size regardless of platform.
-void test03()
-{
-  fb_01.set_size(buffer_size);
-  fb_02.set_size(buffer_size);
-  fb_03.set_size(buffer_size);
-}
-
-// Test overloaded virtual functions.
-void test05() 
-{
-  typedef std::filebuf::int_type 	int_type;
-  typedef std::filebuf::traits_type 	traits_type;
-  typedef std::filebuf::pos_type 	pos_type;
-  typedef std::filebuf::off_type 	off_type;
-  typedef size_t 			size_type;
-
-  bool 					test = true;
-  std::filebuf 				f_tmp;
-  std::streamsize 			strmsz_1, strmsz_2;
-  std::streamoff  			strmof_1, strmof_2;
-  int 					i = 0, j = 0, k = 0;
-
-  fb_01.open(name_01, std::ios_base::in);
-  fb_02.open(name_02, std::ios_base::out | std::ios_base::trunc);
-  fb_03.open(name_03, std::ios_base::out | std::ios_base::in | std::ios_base::trunc);
-
-  int_type c1 = fb_01.sbumpc();
-  int_type c2 = fb_02.sbumpc();
-  int_type c3 = fb_01.sbumpc();
-  int_type c4 = fb_02.sbumpc();
-  int_type c5 = fb_03.sbumpc();
-  int_type c6 = fb_01.sgetc();
-  int_type c7 = fb_02.sgetc();
-  int_type c8 = fb_01.sgetc();
-  int_type c9 = fb_02.sgetc();
-
-  // PUT
-  strmsz_1 = fb_03.sputn("racadabras", 10);//"abracadabras or what?"
-  strmsz_2 = fb_03.sputn(", i wanna reach out and", 10);
-  strmsz_1 = fb_02.sputn("racadabras", 10);
-  strmsz_1 = fb_01.sputn("racadabra", 10);
-
-  // PUTBACK
-  // int_type pbfail(int_type c)
-  // called when gptr() null, gptr() == eback(), or traits::eq(*gptr, c) false
-  // "pending sequence" is:
-  //	1) everything as defined in underflow
-  // 	2) + if (traits::eq_int_type(c, traits::eof()), then input
-  // 	sequence is backed up one char before the pending sequence is
-  // 	determined.
-  //	3) + if (not 2) then c is prepended. Left unspecified is
-  //	whether the input sequence is backedup or modified in any way
-  // returns traits::eof() for failure, unspecified other value for success
-
-  // int_type sputbackc(char_type c)
-  // if in_cur not avail || ! traits::eq(c, gptr() [-1]), return pbfail
-  // otherwise decrements in_cur and returns *gptr()
-  c1 = fb_03.sgetc(); // -1
-  c2 = fb_03.sputbackc('z');
-  strmsz_2 = fb_03.in_avail();
-  c3 = fb_03.sgetc();
-  //test for _in_cur == _in_beg
-  // fb_03._M_out_beg = "bd23456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZracada" etc
-  fb_03.pubseekoff(10, std::ios_base::beg, 
-		   std::ios_base::in | std::ios_base::out);
-  fb_03.sputc('m');
-  strmsz_1 = fb_03.in_avail(); 
-  c1 = fb_03.sgetc(); 
-  fb_03.snextc();
-  c2 = fb_03.sputbackc('z');  
-  strmsz_2 = fb_03.in_avail(); 
-  c3 = fb_03.sgetc();  
-  fb_03.snextc();
-  fb_03.sputc('u');
-  fb_03.sputc('v');
-  fb_03.sputc('a');
-  strmsz_1 = fb_03.in_avail();
-  c2 = fb_03.sputbackc('a');
-  strmsz_2 = fb_03.in_avail();
-  c3 = fb_03.sgetc();
-  //test for ios_base::out
-  c1 = fb_02.sgetc(); // undefined
-  c2 = fb_02.sputbackc('a');
-
-  // int_type sungetc()
-  // if in_cur not avail, return pbackfail(), else decrement and
-  // return to_int_type(*gptr())
-  // fb_03._M_out_beg = "uvaacadabras, i wannaZ[\\]^_`abcdefghijkl"
-  // fb_03._M_out_cur = "aacadabras, i wannaZ[\\]^_`abcdefghijkl"
-  strmsz_1 = fb_03.in_avail();
-  c2 = fb_03.sungetc(); // delete the 'a'
-  strmsz_2 = fb_03.in_avail();
-  VERIFY( c2 == 'v' ); //  VERIFY( c2 != traits_type::eof() );
-  VERIFY( strmsz_1 + 1 == strmsz_2 );
-  //test for _in_cur == _in_beg
-  for (int i = 50; i < 32 + 29; ++i)
-    fb_02.sputc(char(i));
-  fb_02.pubseekoff(0, std::ios_base::beg, std::ios_base::out);
-  c1 = fb_02.sgetc(); 
-  strmsz_1 = fb_02.in_avail();
-  c2 = fb_02.sungetc();
-  c3 = fb_02.sgetc();
-  strmsz_2 = fb_02.in_avail();
-  VERIFY( c1 == c2 );
-  VERIFY( c2 == c3 );
-  VERIFY( c1 == traits_type::eof() );
-  VERIFY( strmsz_1 == strmsz_2 );
-  //test for _in_cur == _in_end
-  fb_03.pubseekoff(0, std::ios_base::end);
-  strmsz_1 = fb_03.in_avail(); // -1 cuz at the end
-  c1 = fb_03.sgetc(); 
-  c2 = fb_03.sungetc();
-  strmsz_2 = fb_03.in_avail(); // 1
-  c3 = fb_03.sgetc();
-  VERIFY( c1 != c2 );
-  // VERIFY( c2 == c3 || c2 == traits_type::not_eof(int(c3)) );
-  VERIFY( strmsz_2 != strmsz_1 );
-  VERIFY( strmsz_2 == 1 );
-  //test for ios_base::out
-}
-
-main() 
-{
-  test03();
-  test05();
-  return 0;
-}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-in.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-in.cc
new file mode 100644
index 0000000..e0814fd
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-in.cc
@@ -0,0 +1,72 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003 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 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.8.1.4 Overridden virtual functions
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "sgetc.txt"; // file with data in it
+
+// Test overloaded virtual functions.
+void test01() 
+{
+  using namespace std;
+  using namespace __gnu_cxx_test;
+  typedef std::filebuf::int_type 	int_type;
+  typedef filebuf::traits_type 		traits_type;
+
+  bool 					test = true;
+  int_type 			        c1, c2, c3;
+
+  // int_type sungetc()
+  // if in_cur not avail, return pbackfail(), else decrement and
+  // return to_int_type(*gptr())
+
+  // in
+  {
+    constraint_filebuf fb_01;
+    fb_01.pubsetbuf(0, 0);
+    fb_01.open(name_01, ios::in);
+    VERIFY( fb_01.unbuffered() );
+    c1 = fb_01.sbumpc();
+    VERIFY( c1 == '/' );
+    c2 = fb_01.sungetc();
+    VERIFY( c2 == c1 );
+    c3 = fb_01.sgetc();
+    VERIFY( c3 == c2 );
+    fb_01.pubseekoff(2, ios_base::beg, ios_base::in);
+    c1 = fb_01.sgetc();
+    VERIFY( c1 == ' ' );
+    c2 = fb_01.sungetc();
+    VERIFY( c2 == traits_type::not_eof(traits_type::eof()) );
+    VERIFY( fb_01.unbuffered() );
+  }
+}
+
+main() 
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-io.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-io.cc
new file mode 100644
index 0000000..24d015c
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-io.cc
@@ -0,0 +1,82 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003 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 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.8.1.4 Overridden virtual functions
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "tmp_sungetc_2io.tst"; // empty file, need to create
+
+void test01() 
+{
+  using namespace std;
+  using namespace __gnu_cxx_test;
+
+  typedef filebuf::int_type 	int_type;
+  typedef filebuf::traits_type 	traits_type;
+  typedef size_t 		size_type;
+
+  bool 				test = true;
+  streamsize 			strmsz_1, strmsz_2;
+  int_type 			c1, c2, c3;
+
+  // int_type sungetc()
+  // if in_cur not avail, return pbackfail(), else decrement and
+  // return to_int_type(*gptr())
+
+  // in | out
+  {
+    constraint_filebuf fb_01;
+    fb_01.pubsetbuf(0, 0);
+    fb_01.open(name_01, ios_base::out | ios_base::in | ios_base::trunc);
+    VERIFY( fb_01.unbuffered() );
+    fb_01.sputc('u');
+    fb_01.sputc('v');
+    fb_01.pubseekoff(-1, std::ios_base::end);
+    c3 = fb_01.sbumpc();
+    strmsz_1 = fb_01.in_avail();
+    c2 = fb_01.sungetc(); 
+    strmsz_2 = fb_01.in_avail();
+    VERIFY( c2 == 'v' ); //  VERIFY( c2 != traits_type::eof() );
+    VERIFY( strmsz_1 + 1 == strmsz_2 );
+    //test for _in_cur == _in_end
+    fb_01.pubseekoff(0, std::ios_base::end);
+    strmsz_1 = fb_01.in_avail(); // -1 cuz at the end
+    c1 = fb_01.sgetc(); 
+    c2 = fb_01.sungetc();
+    strmsz_2 = fb_01.in_avail(); // 1
+    c3 = fb_01.sgetc();
+    VERIFY( c1 != c2 );
+    VERIFY( strmsz_2 != strmsz_1 );
+    VERIFY( strmsz_2 == 1 );
+    VERIFY( fb_01.unbuffered() );
+  }
+}
+
+main() 
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-out.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-out.cc
new file mode 100644
index 0000000..d6cd79f
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-out.cc
@@ -0,0 +1,71 @@
+// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003 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 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.8.1.4 Overridden virtual functions
+
+#include <fstream>
+#include <testsuite_hooks.h>
+#include <testsuite_io.h>
+
+// @require@ %-*.tst %-*.txt
+// @diff@ %-*.tst %*.txt
+
+const char name_01[] = "tmp_sungetc_2out.tst"; // empty file, need to create
+
+// Test overloaded virtual functions.
+void test01() 
+{
+  using namespace std;
+  using namespace __gnu_cxx_test;
+  typedef std::filebuf::int_type 	int_type;
+  typedef filebuf::traits_type 		traits_type;
+
+  bool 					test = true;
+  int_type 			c1, c2, c3;
+
+  // int_type sungetc()
+  // if in_cur not avail, return pbackfail(), else decrement and
+  // return to_int_type(*gptr())
+
+  // out
+  {
+    constraint_filebuf fb_01; // out
+    fb_01.pubsetbuf(0, 0);
+    fb_01.open(name_01, ios::out | ios::trunc);    
+    VERIFY( fb_01.unbuffered() );
+    VERIFY( !fb_01.read_position() );
+    c1 = fb_01.sgetc();
+    VERIFY( c1 == traits_type::eof() );
+    c2 = fb_01.sungetc();
+    VERIFY( c2 == traits_type::eof() );
+    fb_01.sbumpc();
+    c1 = fb_01.sbumpc();
+    c2 = fb_01.sungetc();
+    VERIFY( c1 == c2 );
+    VERIFY( fb_01.unbuffered() );
+    VERIFY( !fb_01.read_position() );
+  }
+}
+
+main() 
+{
+  test01();
+  return 0;
+}