[TYPO3-core] RFC: #2302: substitute all strtoupper/strtolower with the t3lib_div-method

[Ernesto Baschny [cron IT]]

Martin Kutschker wrote: on 28.06.2008 18:44:

>> This is an SVN patch request.
>>
>> Type: Bugfix
>>
>> Bugtracker reference:
>> http://bugs.typo3.org/view.php?id=2302
>>
>> Branches: trunk
>>
>> Problem: strtoupper and strtolower are not multibyte-safe. For this reason 
>> we added 2 methods in t3lib_div sometime ago.
> 
> No, this is a misunderstanding! The sole purpose of this two function is
> to provide a locale independent conversion (needed for Turkish).
> 
> It's only meant for 7bit ASCII data, ie strings that are know to contain
> only a-z and A-Z (eg by definition markers, etc)
> 
> Do NOT use it it on arbitary string especially not utf8.
> 
> If you need  to upper case utf or other charsets use t3lib_cs->case().

I would suggest to make the function documentation more precise. It 
currently says:

          * Converts string to lowercase
          * The function converts all Latin characters (A-Z, but no 
accents, etc) to
          * lowercase. It is safe for all supported character sets 
(incl. utf-8).
          * Unlike strtolower() it does not honour the locale.

First it shouldn't say it works on "all Latin characters", but on all 
ASCII (7-bit) characters. Then "it is safe for all supported character 
sets (incl. utf-8)" is even more misleading. We know what it means, but 
someone that doesn't might think this function can convert even UTF-8 
data to lowercase. So I suggest to have it like:

	* Converts ASCII strings to lowercase
	* Only A-Z character are considered. Only use this method for
	* strings where you expect only ASCII characters (e.g. markers).
	* Unlike strtolower() it does not honour the locale (i.e. also
	* works on turkish locale).

And an equivalent for the strtoupper method.

Cheers,
Ernesto