679 	    if (i == NUL)	// just in case mblen() can't handle ""  in mb_init()
778 	if (*curbuf->b_p_fenc == NUL)  in bomb_size()
839 	if (p[0] == NUL || VIM_ISWHITE(p[0]))  in mb_get_class_buf()
845     if (enc_dbcs != 0 && p[0] != NUL && p[1] != NUL)  in mb_get_class_buf()
1065 	if (buf[1] == NUL)  in dbcs_char2bytes()
1093     if (len == 2 && p[1] == NUL)  in dbcs_ptr2len()
1107     if (size < 1 || *p == NUL)  in latin_ptr2len_len()
1117     if (size < 1 || *p == NUL)  in dbcs_ptr2len_len()
1123     if (len == 2 && p[1] == NUL)  in dbcs_ptr2len_len()
1627 	if (utf_ptr2len(p) == 1 || c == NUL)  in utf_ptr2cells()
1670 	if (utf_ptr2len(p) == 1 || c == NUL)  in utf_ptr2cells_len()
1722     for (i = 0; (len < 0 || i < len) && p[i] != NUL; i += (*mb_ptr2len)(p + i))  in mb_string2cells()
1771     if (MB_BYTE2LEN(*p) > 1 && p[1] != NUL)  in dbcs_ptr2char()
2051     if (*p == NUL)  in utf_ptr2len()
2112     if (b0 == NUL)  in utfc_ptr2len()
2158     if (size < 1 || *p == NUL)  in utfc_ptr2len_len()
2878 	if (c == ' ' || c == '\t' || c == NUL || c == 0xa0)  in utf_class_buf()
3666     while (n1 > 0 && n2 > 0 && *s1 != NUL && *s2 != NUL)  in utf_strnicmp()
3678     if (n1 > 0 && *s1 == NUL)  in utf_strnicmp()
3680     if (n2 > 0 && *s2 == NUL)  in utf_strnicmp()
3711 	    if (s1[i] == NUL && s2[i] == NUL)	// both strings end  in mb_strnicmp()
3776 		(line[i] == NL) ? NUL : line[i]);  // NUL is stored as NL  in show_utf8()
3805     if (p <= base || MB_BYTE2LEN(p[-1]) == 1 || *p == NUL)  in dbcs_head_off()
3832 	    || *p == NUL)  in dbcs_screen_head_off()
4117     if (*p == NUL)  in mb_tail_off()
4136     if (enc_dbcs == 0 || p[1] == NUL || MB_BYTE2LEN(*p) == 1)  in mb_tail_off()
4177 	while (*p != NUL)  in utf_find_illegal()
4192 		    for (p = ml_get_cursor(); *p != NUL && len-- > 0; p += l)  in utf_find_illegal()
4229     while (end == NULL ? *p != NUL : p < end)  in utf_valid_string()
4256     if (*p == NUL || p[1] == NUL  in dbcs_screen_tail_off()
4289 	if (*p == NUL || (int)STRLEN(p) < lp->col)  in mb_adjustpos()
4329     for (count = 0; *p != NUL; count++)  in mb_charlen()
4344     for (count = 0; *p != NUL && p < str + len; count++)  in mb_charlen_len()
4368     for (n = 0; str[n] != NUL && m < 4; ++n)  in mb_unescape()
4396 	buf[m] = NUL;  in mb_unescape()
4439 		    && ScreenLines[off] != NUL  in mb_fix_col()
4496 	for (s = enc; *s != NUL; ++s)  in enc_canonize()
4503 	*p = NUL;  in enc_canonize()
4580     if (s == NULL || *s == NUL)  in enc_locale_env()
4581 	if ((s = getenv("LC_ALL")) == NULL || *s == NUL)  in enc_locale_env()
4582 	    if ((s = getenv("LC_CTYPE")) == NULL || *s == NUL)  in enc_locale_env()
4585     if (s == NULL || *s == NUL)  in enc_locale_env()
4610     for (i = 0; i < (int)sizeof(buf) - 1 && s[i] != NUL; ++i)  in enc_locale_env()
4619     buf[i] = NUL;  in enc_locale_env()
4650     if ((s = nl_langinfo(CODESET)) == NULL || *s == NUL)  in enc_locale()
4653 	if ((s = setlocale(LC_CTYPE, NULL)) == NULL || *s == NUL)  in enc_locale()
4795 	    *to = NUL;  in iconv_string()
4805 	    *to = NUL;  in iconv_string()
5046     if (from == NULL || *from == NUL || to == NULL || *to == NUL  in convert_setup_ext()
5249 	    *d = NUL;  in string_convert_ext()
5275 	    *d = NUL;  in string_convert_ext()
5290 		    *d++ = NUL;  in string_convert_ext()
5351 	    *d = NUL;  in string_convert_ext()
5407 			retval[0] = NUL;  in string_convert_ext()
5435 		retval[retlen] = NUL;  in string_convert_ext()