POSIX doesn't specify behavior for wcsrtombs and mbsrtowcs when the
source parameter is NULL.
http://pubs.opengroup.org/onlinepubs/009695399/functions/mbsrtowcs.html
http://pubs.opengroup.org/onlinepubs/009695399/functions/wcsrtombs.html
However segfaulting in such cases, as happens with this example,
IMHO, is not desirable.
------- nullsrc.c
#include <locale.h>
#include <stdio.h>
#include <string.h>
#include <wchar.h>
int main() {
char *msrc = NULL;
char mdst[100];
wchar_t *wsrc = NULL;
wchar_t wdst[100];
size_t s;
mbstate_t mbst;
bzero(&mbst, sizeof(mbst));
mbsinit(&mbst);
s = wcsrtombs(mdst, (const wchar_t **)&wsrc, 5, &mbst);
printf("fixed wcsrtombs without encoding\n");
s = mbsrtowcs(wdst, (const char **)&msrc, 5, &mbst);
printf("fixed mbsrtowcs without encoding\n");
setlocale(LC_ALL, "POSIX.UTF-8");
s = wcsrtombs(mdst, (const wchar_t **)&wsrc, 5, &mbst);
printf("fixed wcsrtombs with UTF-8\n");
s = mbsrtowcs(wdst, (const char **)&msrc, 5, &mbst);
printf("fixed mbsrtowcs with UTF-8\n");
return 0;
}
---
cc -g -o nullsrc nullsrc.c
gdb nullsrc
...
(gdb) run
Starting program: /home/vtamara/tmp/nullsrc
Program received signal SIGSEGV, Segmentation fault.
_citrus_none_ctype_wcsnrtombs (dst=0x7f7ffffbee90 "",
src=0x7f7ffffbee80, nwc=18446744073709551615, len=5,
pspriv=0x7f7ffffbee00)
at /usr/src/lib/libc/citrus/citrus_none.c:155
155 wchar_t wc = (*src)[i];
---
The attached patch solves this by setting errno in EINVAL and
returning (size_t)-1 when the source parameter is NULL or points
to NULL, also includes this information in the man page.
--
Dios, gracias por tu amor infinito.
--
Vladimir Támara Patiño. http://vtamara.pasosdeJesus.org/
http://www.pasosdejesus.org/dominio_publico_colombia.html
diff -u src56-orig/lib/libc/citrus/citrus_none.c
src/lib/libc/citrus/citrus_none.c
--- src56-orig/lib/libc/citrus/citrus_none.c Thu Mar 7 13:12:31 2013
+++ src/lib/libc/citrus/citrus_none.c Wed Oct 1 12:45:17 2014
@@ -93,6 +93,10 @@
/* dst may be NULL */
/* pspriv appears to be unused */
+ if (src == NULL || *src == NULL) {
+ errno = EINVAL;
+ return ((size_t)-1);
+ }
if (dst == NULL)
return strnlen(*src, nmc);
@@ -138,6 +142,10 @@
/* dst may be NULL */
/* pspriv appears to be unused */
+ if (src == NULL || *src == NULL) {
+ errno = EINVAL;
+ return ((size_t)-1);
+ }
if (dst == NULL) {
for (i = 0; i < nwc; i++) {
wchar_t wc = (*src)[i];
diff -u src56-orig/lib/libc/citrus/citrus_utf8.c
src/lib/libc/citrus/citrus_utf8.c
--- src56-orig/lib/libc/citrus/citrus_utf8.c Fri Sep 19 13:07:15 2014
+++ src/lib/libc/citrus/citrus_utf8.c Wed Oct 1 12:44:01 2014
@@ -194,6 +194,10 @@
us = (struct _utf8_state *)pspriv;
+ if (src == NULL || *src == NULL) {
+ errno = EINVAL;
+ return ((size_t)-1);
+ }
if (dst == NULL) {
/*
* The fast path in the loop below is not safe if an ASCII
@@ -346,6 +350,10 @@
return ((size_t)-1);
}
+ if (src == NULL || *src == NULL) {
+ errno = EINVAL;
+ return ((size_t)-1);
+ }
if (dst == NULL) {
for (i = o = 0; i < nwc; i++, o += r) {
wchar_t wc = (*src)[i];
diff -u src56-orig/lib/libc/locale/mbsrtowcs.3 src/lib/libc/locale/mbsrtowcs.3
--- src56-orig/lib/libc/locale/mbsrtowcs.3 Tue Jun 4 22:39:22 2013
+++ src/lib/libc/locale/mbsrtowcs.3 Wed Oct 1 13:34:47 2014
@@ -151,8 +151,8 @@
is a null pointer, the value returned is the number of elements to contain
the whole string converted, except for a terminating null wide character.
.It (size_t)-1
-The array indirectly pointed to by
.Fa src
+is NULL or points to NULL or to an array that
contains a byte sequence forming invalid character.
In this case,
.Va errno
@@ -167,9 +167,8 @@
functions may return the following errors:
.Bl -tag -width Er
.It Bq Er EILSEQ
-The pointer pointed to by
.Fa src
-points to an invalid or incomplete multibyte character.
+is NULL or points to NULL or to an invalid or incomplete multibyte character.
.It Bq Er EINVAL
.Fa ps
points to an invalid or uninitialized mbstate_t object.
diff -u src56-orig/lib/libc/locale/wcsrtombs.3 src/lib/libc/locale/wcsrtombs.3
--- src56-orig/lib/libc/locale/wcsrtombs.3 Tue Jun 4 22:39:22 2013
+++ src/lib/libc/locale/wcsrtombs.3 Wed Oct 1 13:37:31 2014
@@ -153,7 +153,7 @@
will not be null-terminated.
.It (size_t)-1
.Fa src
-points to the string containing invalid wide character.
+is NULL or points to NULL or to a string containing invalid wide character.
In this case,
.Va errno
is set to indicate the error.
@@ -168,7 +168,7 @@
.Bl -tag -width Er
.It Bq Er EILSEQ
.Fa src
-points to the string containing an invalid wide character.
+is NULL or points to NULL or to a string containing an invalid wide character.
.It Bq Er EINVAL
.Fa ps
points to an invalid or uninitialized mbstate_t object.
