diff options
| author | Todd C. Miller <millert@cvs.openbsd.org> | 1998-07-27 02:28:29 +0000 |
|---|---|---|
| committer | Todd C. Miller <millert@cvs.openbsd.org> | 1998-07-27 02:28:29 +0000 |
| commit | d3d6a4e5860715c18435ff8da6670bc7f5caf695 (patch) | |
| tree | 20fdf74c2f5c8f6bd900aa430ad75199c3a62041 /lib | |
| parent | f07bd065d9ebe2c7f630bab745a468d7def06a1b (diff) | |
Use a single character buffer for the size==0 case. Stdio internals do not deal correctly with zero size buffer and NULL pointer. torek@bsdi.com
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/libc/stdio/vsnprintf.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/lib/libc/stdio/vsnprintf.c b/lib/libc/stdio/vsnprintf.c index b965b146442..3fe0bb07af9 100644 --- a/lib/libc/stdio/vsnprintf.c +++ b/lib/libc/stdio/vsnprintf.c @@ -35,7 +35,7 @@ */ #if defined(LIBC_SCCS) && !defined(lint) -static char rcsid[] = "$OpenBSD: vsnprintf.c,v 1.4 1998/01/12 06:14:32 millert Exp $"; +static char rcsid[] = "$OpenBSD: vsnprintf.c,v 1.5 1998/07/27 02:28:28 millert Exp $"; #endif /* LIBC_SCCS and not lint */ #include <limits.h> @@ -49,17 +49,22 @@ vsnprintf(str, n, fmt, ap) _BSD_VA_LIST_ ap; { int ret; + char dummy; FILE f; /* While snprintf(3) specifies size_t stdio uses an int internally */ if (n > INT_MAX) n = INT_MAX; + /* Stdio internals do not deal correctly with zero length buffer */ + if (n == 0) { + str = &dummy; + n = 1; + } f._file = -1; f._flags = __SWR | __SSTR; f._bf._base = f._p = (unsigned char *)str; - f._bf._size = f._w = n ? n - 1 : 0; + f._bf._size = f._w = n - 1; ret = vfprintf(&f, fmt, ap); - if (n) - *f._p = '\0'; + *f._p = 0; return (ret); } |