1 // Copyright (C) 2003-2018 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
24 class Cvt : public std::codecvt<wchar_t, char, std::mbstate_t>
25 {
26 public:
27 mutable bool unshift_called;
28
Cvt()29 Cvt()
30 : unshift_called(false)
31 { }
32
33 protected:
34 bool
do_always_noconv() const35 do_always_noconv() const throw()
36 { return false; }
37
38 int
do_encoding() const39 do_encoding() const throw()
40 { return -1; }
41
42 std::codecvt_base::result
do_unshift(std::mbstate_t &,char * to,char *,char * & to_next) const43 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()
test01()53 void test01()
54 {
55 using namespace std;
56
57 const char* name = "tmp_seekpos_12790";
58
59 Cvt* cvt = new Cvt;
60 locale loc(locale::classic(), cvt);
61
62 wfilebuf fb;
63 fb.pubimbue(loc);
64
65 fb.open(name, ios_base::out);
66 streampos pos = fb.pubseekoff(0, ios_base::beg);
67 fb.sputc(L'a');
68
69 VERIFY( !cvt->unshift_called );
70 fb.pubseekpos(pos);
71 VERIFY( cvt->unshift_called );
72 }
73
main()74 int main()
75 {
76 test01();
77 return 0;
78 }
79