diff options
| author | Mark H Weaver <mhw@netris.org> | 2019-04-01 22:11:35 -0400 |
|---|---|---|
| committer | Mark H Weaver <mhw@netris.org> | 2019-04-16 16:54:55 -0400 |
| commit | 6b1de860ab2360e8679205aecdc1c837744a4b9c (patch) | |
| tree | 0357dcee473b12ca590343ad513d876eca1e8199 /libguile/stime.c | |
| parent | 275c96dd1fbc392e43423e91f08d2cf2fcc538a1 (diff) | |
Avoid passing NULL to 'memcpy' and 'memcmp'.
Reported by Jeffrey Walton <noloader@gmail.com> in
<https://lists.gnu.org/archive/html/guile-devel/2019-03/msg00001.html>.
Note that C11 section 7.1.4 (Use of library functions) states that:
"unless explicitly stated otherwise in the detailed descriptions [of
library functions] that follow: If an argument to a function has an
invalid value (such as ... a null pointer ...) ..., the behavior is
undefined." Note that 'strxfrm' is an example of a standard C function
that explicitly states otherwise, allowing NULL to be passed in the
first argument if the size argument is zero, but no similar allowance is
specified for 'memcpy' or 'memcmp'.
* libguile/bytevectors.c (scm_uniform_array_to_bytevector): Call memcpy
only if 'byte_len' is non-zero.
* libguile/srfi-14.c (charsets_equal): Call memcmp only if the number of
ranges is non-zero.
* libguile/stime.c (setzone): Pass 1-character buffer to
'scm_to_locale_stringbuf', instead of NULL.
* libguile/strings.c (scm_to_locale_stringbuf): Call memcpy only if the
number of bytes to copy is non-zero.
Diffstat (limited to 'libguile/stime.c')
| -rw-r--r-- | libguile/stime.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/libguile/stime.c b/libguile/stime.c index 060a49642..b681d7ee3 100644 --- a/libguile/stime.c +++ b/libguile/stime.c @@ -340,10 +340,11 @@ setzone (SCM zone, int pos, const char *subr) if (!SCM_UNBNDP (zone)) { static char *tmpenv[2]; + char dummy_buf[1]; char *buf; size_t zone_len; - zone_len = scm_to_locale_stringbuf (zone, NULL, 0); + zone_len = scm_to_locale_stringbuf (zone, dummy_buf, 0); buf = scm_malloc (zone_len + sizeof (tzvar) + 1); strcpy (buf, tzvar); buf[sizeof(tzvar)-1] = '='; |