Gettext will always use system default locale

Question

I need to localise a Windows-only PHP web application and I'm evaluating the gettext extension but I'm having the hardest time trying to make it work in my Windows 7 development box. I've used trial and error together with Process Monitor to overcome the poor and inaccurate documentation and I've managed to make _() display strings from the *.po catalogue that corresponds to the computer's default locale (Modern Spanish in my case). All my attempts to set a different locale are silently ignored.

I've written a test script with lots of redundant stuff:

<dl><?php

define('DIR_LOCALE', __DIR__ . DIRECTORY_SEPARATOR . 'locale');
bindtextdomain('general', DIR_LOCALE);
bind_textdomain_codeset('general', 'UTF-8');
textdomain('general');

if(!defined('LC_MESSAGES')){
    define('LC_MESSAGES', 5);
}

$pruebas = array(
    'enu',
    'es_ES',
    'en_GB',
    'english-uk',
    'Spanish_Spain.1252',
    'esn',
    'spanish',
    'spanish-modern',
);
foreach($pruebas as $locale){
    putenv("LC_ALL=$locale");
    setlocale(LC_ALL, $locale);

    putenv("LC_MESSAGES=$locale");
    setlocale(LC_MESSAGES, $locale);

    putenv("LANGUAGE=$locale");
    putenv("LANG=$locale");
?>
    <dt><?=htmlspecialchars($locale)?></dt>
    <dd><?=_('codigo_idioma')?></dd>
<?php } ?>
</dl>

In my case, <?=_('codigo_idioma')?> always prints es_ES@modern.

I have PHP/5.4.5 but I'm expecting to get it working in any reasonably up-to-date server our customers own.

I've read lots of vague references about the need to install locales even on Windows but no exact details. What can the problem be?

^{(I'm aware that the common advice is to dump gettext and use any other library.)}

---

Further testing:

My code run flawlessly as-is in another two computers: 32-bit Windows Vista and 32-bit Windows 7 32-bit. It fails in my computer (64-bit Windows 7) and another one (32-bit Windows Server 2003)

• Apache version seems irrelevant (it also happens with the command-line interpreter).
• PHP version seems irrelevant (also tried latest 32-bit PHP/5.5.5 in my PC).
• My [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls] registry tree is identical to the other Seven box.

Edit: While testing on the command-line, I've discovered that setting the LANG environment variable before running the PHP script finally changes the language:

C:\>set LANG=en_GB
C:\>php C:\test\gettext.php

This definitively proves that my computer has the correct assets but also makes me wonder why PHP claims that putenv() works and then ignores it:

var_dump( getenv('LANG'), putenv('LANG=en_GB'), getenv('LANG') );

bool(false)
bool(true)
string(5) "en_GB"

Even this doesn't have any effect:

$_ENV['LANG'] = 'en_GB';
$_SERVER['LANG'] = 'en_GB';

Answer 1

It's an issue that's been acknowledged and partially fixed by the PHP team.

It's a fairly technical thing, apparently related to the way environment variables (on which gettext heavily depends) are handled by the underlying platform. Also, something has changed in the Visual C Runtime libraries from VC9 to VC11 that affects all this.

To sum up:

• Non thread-safe builds have been fixed in the source tree on 21^st Nov. 2014.
• Thread-safe builds (e.g. Apache module) haven't and there isn't a clear solution in sight.