glibc/libio/tst-wmemstream3.c

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libio: Multiple fixes for open_{w}memstram (BZ#18241 and BZ#20181) This patches fixes multiples issues on open_{w}memstream reported on both BZ#18241 and BZ#20181: - failed fseek does not set errno. - negative offset in fseek fails even when resulting position is a valid one. - a flush after write if the current write position is not at the end of the stream currupt data. The main fix is on seek operation for memstream (_IO_{w}str_seekoff), where both _IO_read_ptr and _IO_read_end pointer are updated if a write operation has occured (similar to default file operations). Also, to calculate the offset on both read and write pointers, a temporary value is instead of updating the argument supplied value. Negative offset are valid if resulting internal pointer is within the range of _IO_{read,write}_base and _IO_{read,write}_end. Also POSIX states that a null or wide null shall be appended to the current buffer iff a write moves the position to a value larger than the current lenght. Current implementation appends a null or wide null regardless of this condition. This patch fixes it by removing the 'else' condition on _IO_{w}mem_sync. Checked on x86_64. [BZ #18241] [BZ #20181] * libio/Makefile (test): Add tst-memstream3 and tst-wmemstream3. * libio/memstream.c (_IO_mem_sync): Only append a null byte if write position is at the end the buffer. * libio/wmemstream.c (_IO_wmem_sync): Likewise. * libio/strops.c (_IO_str_switch_to_get_mode): New function. (_IO_str_seekoff): Set correct offset from negative displacement and set EINVAL for invalid ones. * libio/wstrops.c (enlarge_userbuf): Use correct function to calculate buffer length. (_IO_wstr_switch_to_get_mode): New function. (_IO_wstr_seekoff): Set correct offset from negative displacement and set EINVAL for invalid ones. * libio/tst-memstream3.c: New file. * libio/tst-wmemstream3.c: Likewise. * manual/examples/memstrm.c: Remove warning when priting size_t.
2016-07-25 17:54:29 +00:00
/* Test for open_memstream implementation.
Copyright (C) 2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <wchar.h>
/* Straighforward implementation so tst-memstream3 could use check
fwrite on open_memstream. */
static size_t
fwwrite (const void *ptr, size_t size, size_t nmemb, FILE *arq)
{
const wchar_t *wcs = (const wchar_t*) (ptr);
for (size_t s = 0; s < size; s++)
{
for (size_t n = 0; n < nmemb; n++)
if (fputwc (wcs[n], arq) == WEOF)
return n;
}
return size * nmemb;
}
#define CHAR_T wchar_t
#define W(o) L##o
#define OPEN_MEMSTREAM open_wmemstream
#define PRINTF wprintf
#define FWRITE fwwrite
#define FPUTC fputwc
#define STRCMP wcscmp
#include "tst-memstream3.c"