5158 sed dumps core in new multibyte code
Reviewed by: Toomas Soome <tsoome@me.com>

@@ -37,10 +37,15 @@
 
 size_t
 mbsrtowcs_l(wchar_t *_RESTRICT_KYWD dst, const char **_RESTRICT_KYWD src,
     size_t len, mbstate_t *_RESTRICT_KYWD ps, locale_t loc)
 {
+        static mbstate_t mbs;
+
+        if (ps == NULL)
+                ps = &mbs;
+
         return (loc->ctype->lc_mbsnrtowcs(dst, src, ULONG_MAX, len, ps));
 }
 
 size_t
 mbsrtowcs(wchar_t *_RESTRICT_KYWD dst, const char **_RESTRICT_KYWD src,