1// Copyright (C) 2003, 2009 Free Software Foundation, Inc. 2// 3// This file is part of the GNU ISO C++ Library. This library is free 4// software; you can redistribute it and/or modify it under the 5// terms of the GNU General Public License as published by the 6// Free Software Foundation; either version 3, or (at your option) 7// any later version. 8 9// This library is distributed in the hope that it will be useful, 10// but WITHOUT ANY WARRANTY; without even the implied warranty of 11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12// GNU General Public License for more details. 13 14// You should have received a copy of the GNU General Public License along 15// with this library; see the file COPYING3. If not see 16// <http://www.gnu.org/licenses/>. 17 18// 27.8.1.4 Overridden virtual functions 19 20#include <locale> 21#include <fstream> 22#include <testsuite_hooks.h> 23 24class Cvt : public std::codecvt<char, char, std::mbstate_t> 25{ 26public: 27 mutable bool unshift_called; 28 29 Cvt() 30 : unshift_called(false) 31 { } 32 33protected: 34 bool 35 do_always_noconv() const throw() 36 { return false; } 37 38 int 39 do_encoding() const throw() 40 { return -1; } 41 42 std::codecvt_base::result 43 do_unshift(std::mbstate_t&, char* to, char*, char*& to_next) const 44 { 45 unshift_called = true; 46 to_next = to; 47 return std::codecvt_base::ok; 48 } 49}; 50 51// libstdc++/12790 52// basic_filebuf::seekpos() should call codecvt::unshift(), 53// but only if writing 54void test01() 55{ 56 using namespace std; 57 58 bool test __attribute__((unused)) = true; 59 const char* name = "tmp_seekpos_12790"; 60 61 Cvt* cvt = new Cvt; 62 locale loc(locale::classic(), cvt); 63 64 filebuf fb; 65 fb.pubimbue(loc); 66 67 fb.open(name, ios_base::out); 68 streampos pos = fb.pubseekoff(0, ios_base::beg); 69 70 VERIFY( !cvt->unshift_called ); 71 fb.pubseekpos(pos); 72 VERIFY( !cvt->unshift_called ); 73} 74 75int main() 76{ 77 test01(); 78 return 0; 79} 80