tuklib_mbstr_width: Use stricter return value checking

This should make no difference in practice (at least if mbrtowc()
isn't broken).

diff --git a/src/common/tuklib_mbstr_width.c b/src/common/tuklib_mbstr_width.c
index 3c63dd1aa6fee3e3fc65981b902dbbf0292db2b9..e7052235d49ce96cc4caca30783280105db94806 100644 (file)
--- a/src/common/tuklib_mbstr_width.c
+++ b/src/common/tuklib_mbstr_width.c
@@ -41,7 +41,7 @@ tuklib_mbstr_width(const char *str, size_t *bytes)
        while (i < len) {
                wchar_t wc;
                const size_t ret = mbrtowc(&wc, str + i, len - i, &state);
-               if (ret < 1 || ret > len)
+               if (ret < 1 || ret > len - i)
                        return (size_t)-1;
 
                i += ret;