How will it affect those without mb_strlen (any situations) and whether it can be incorporated wherever strlen is used in both FA 2.3 and 2.4? Any changes here will have to be carried through to everywhere it is used.

Please note that mb_strlen is used in both A 2.3 and 2.4 in the following files:

reporting/includes/class.graphic.inc
reporting/includes/Workbook.php

The usage in the last file above is:

    $strlen = function_exists('mb_strlen') ? mb_strlen($str, 'UTF-16LE') : (strlen($str) / 2);

whilst in the former it is:

    $width = mb_strlen($string, "UTF-8");

@itronics: Using VARCHAR results in slightly bigger memory usage, and slower processing (though probably both issues are hardly noticed).Using VARCHAR results in slightly bigger memory usage, and slower processing (though probably both issues are hardly noticed).

@itronics: Regarding mb_strlen function, it should be used indeed, but it is available only when mbstring php extension is enabled, so to avoid problems the conditional call should be used as it is done in Workbook.php.

References:

* What Every Programmer Absolutely, Positively Needs to Know About Encodings and Character Sets to Work With Text

* php.ini mbstring overload

In the actual statement the prefix is displayed 1:1

Display the actual SQL statement after replacement of the variables and compare with the $ref_fld value. Refer Troubleshooting FA in the wiki.

// retrieve last ref number in the refline from original transaction table
$sql = "SELECT MAX(CAST(SUBSTR($ref_fld, ".(strlen($prefix)+1).",LENGTH($ref_fld)-".(strlen($postfix)+strlen($prefix)).") AS UNSIGNED))"
                ." FROM `$trans_table` tbl
                    LEFT JOIN ".TB_PREF."voided v ON tbl.`$tno_fld`=v.id AND v.type=$type"
                ." WHERE ISNULL(v.id)"
                .($type_fld ? " AND tbl.`$type_fld`=$type" : '')
                ." AND `$ref_fld` REGEXP ".db_escape('^'.preg_quote($prefix).'[0-9]*'.preg_quote($postfix).'$');

It is increased to 12. All refs are recorded and recalled correctly, but the auto increment of reflines with prefix longer than 5 characters is not working.

It looks like this and with the short prefixes works perfect, so i guess this is hard-coded somewhere else about the auto increment, and I can't find where.

Here is the DB table config:

`prefix` varchar(12) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',

If so, you might want to increase the prefix size from the default of 5 in the table:

ALTER TABLE `0_reflines` CHANGE `prefix` `prefix` CHAR(10) DEFAULT '' NOT NULL; 

I need the long prefixes for Sales Orders and Delivery Notes