1/* Verify that ftell does not go into an infinite loop when a conversion fails
2 due to insufficient space in the buffer.
3 Copyright (C) 2014-2022 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <wchar.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <locale.h>
25#include <errno.h>
26#include <unistd.h>
27
28static int do_test (void);
29#define TEST_FUNCTION do_test ()
30#include "../test-skeleton.c"
31
32/* Arbitrary number large enough so that the target buffer during conversion is
33 not large enough. */
34#define STRING_SIZE (1400)
35#define NSTRINGS (2)
36
37static int
38do_test (void)
39{
40 FILE *fp = NULL;
41 wchar_t *inputs[NSTRINGS] = {NULL};
42 int ret = 1;
43
44 if (setlocale (LC_ALL, "en_US.UTF-8") == NULL)
45 {
46 printf (format: "Cannot set en_US.UTF-8 locale.\n");
47 goto out;
48 }
49
50
51 /* Generate input from one character, chosen because it has an odd number of
52 bytes in UTF-8, making it easier to reproduce the problem:
53
54 NAME Hiragana letter GO
55 CHAR ご
56 UTF-8 E38194
57 UCS 3054
58 MARC-8 692434 */
59 wchar_t seed = L'ご';
60 for (int i = 0; i < NSTRINGS; i++)
61 {
62 inputs[i] = malloc (STRING_SIZE * sizeof (wchar_t));
63 if (inputs[i] == NULL)
64 {
65 printf (format: "Failed to allocate memory for inputs: %m\n");
66 goto out;
67 }
68 wmemset (inputs[i], seed, STRING_SIZE - 1);
69 inputs[i][STRING_SIZE - 1] = L'\0';
70 }
71
72 char *filename;
73 int fd = create_temp_file (base: "tst-fseek-wide-partial.out", filename: &filename);
74
75 if (fd == -1)
76 {
77 printf (format: "create_temp_file: %m\n");
78 goto out;
79 }
80
81 fp = fdopen (fd, "w+");
82 if (fp == NULL)
83 {
84 printf (format: "fopen: %m\n");
85 close (fd: fd);
86 goto out;
87 }
88
89 for (int i = 0; i < NSTRINGS; i++)
90 {
91 printf (format: "offset: %ld\n", ftell (stream: fp));
92 if (fputws (ws: inputs[i], stream: fp) == -1)
93 {
94 perror ("fputws");
95 goto out;
96 }
97 }
98 ret = 0;
99
100out:
101 if (fp != NULL)
102 fclose (fp);
103 for (int i = 0; i < NSTRINGS; i++)
104 free (ptr: inputs[i]);
105
106 return ret;
107}
108

source code of glibc/libio/tst-ftell-partial-wide.c