// 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>

// Copyright (C) 2001-2024 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>

const char name_08[] = "filebuf_virtuals-8.txt"; // empty file, need to create

class OverBuf : public std::filebuf
{
public:
  int_type pub_overflow(int_type c = traits_type::eof())
  { return std::filebuf::overflow(c); }
};

// libstdc++/9988
// filebuf::overflow writes EOF to file
void test15()
{
  using namespace std;
  
  OverBuf fb;
  fb.open(name_08, ios_base::out | ios_base::trunc);
  
  fb.sputc('a');
  fb.pub_overflow('b');
  fb.pub_overflow();
  fb.sputc('c');
  fb.close();

  filebuf fbin;
  fbin.open(name_08, ios_base::in);
  filebuf::int_type c;
  c = fbin.sbumpc();
  VERIFY( c == 'a' );
  c = fbin.sbumpc();
  VERIFY( c == 'b' );
  c = fbin.sbumpc();
  VERIFY( c == 'c' );
  c = fbin.sbumpc();
  VERIFY( c == filebuf::traits_type::eof() );
  fbin.close();
}

int main() 
{
  test15();
  return 0;
}
