libio: Fix fmemopen 'w' mode with provided buffer
Commit Message
If 'w' mode is used with a provided buffer the fmemopen will try to find
the first null byte to set as maximum internal stream size. It should be
done only for append mode ('a').
Kudos for Stefan Liebler for finding this error on s390-32.
--
* libio/fmemopen.c (__fmemopen): Fix 'w' openmode with provided
buffer.
* stdio-common/tst-fmemopen2.c (do_test_with_buffer): Typo.
--
Comments
On 07/16/2015 07:46 AM, Adhemerval Zanella wrote:
> If 'w' mode is used with a provided buffer the fmemopen will try to find
> the first null byte to set as maximum internal stream size. It should be
> done only for append mode ('a').
>
> Kudos for Stefan Liebler for finding this error on s390-32.
>
> --
>
> * libio/fmemopen.c (__fmemopen): Fix 'w' openmode with provided
> buffer.
> * stdio-common/tst-fmemopen2.c (do_test_with_buffer): Typo.
OK for 2.22
c.
@@ -150,7 +150,7 @@ __fmemopen (void *buf, size_t len, const char *mode)
cookie_io_functions_t iof;
fmemopen_cookie_t *c;
- c = (fmemopen_cookie_t *) malloc (sizeof (fmemopen_cookie_t));
+ c = (fmemopen_cookie_t *) calloc (sizeof (fmemopen_cookie_t), 1);
if (c == NULL)
return NULL;
@@ -165,7 +165,6 @@ __fmemopen (void *buf, size_t len, const char *mode)
return NULL;
}
c->buffer[0] = '\0';
- c->maxpos = 0;
}
else
{
@@ -182,7 +181,8 @@ __fmemopen (void *buf, size_t len, const char *mode)
if (mode[0] == 'w' && mode[1] == '+')
c->buffer[0] = '\0';
- c->maxpos = strnlen (c->buffer, len);
+ if (mode[0] == 'a')
+ c->maxpos = strnlen (c->buffer, len);
}
@@ -34,7 +34,7 @@ do_test_with_buffer (void)
FILE *fp = fmemopen (buf, nbuf, "w");
if (fp == NULL)
{
- printf ("FAIL: fmemopen failedi (%s)\n", __FUNCTION__);
+ printf ("FAIL: fmemopen failed (%s)\n", __FUNCTION__);
return 1;
}