I was setting up for some code today. Code which would use, among other things, Smarty 3 since that’s a thing now apparently. (It used to be Smarty 2, but I guess times change and numbers change.)

There’s an __autoload function that I wrote a while ago and often use to, you know, automatically include files when instantiating classes. But it didn’t work at all.
The file itself with the __autoload function included fine, but autoload function was not being called. It was pretty confusing, to be honest.

Jeff and I eventually traced this back to one line in my code — the line including the Smarty source file.

So I had a look in there and found this:

/**
 * register the class autoloader
 */
if (!defined('SMARTY_SPL_AUTOLOAD')) {
    define('SMARTY_SPL_AUTOLOAD', 0);
}

if (SMARTY_SPL_AUTOLOAD && set_include_path(get_include_path() . PATH_SEPARATOR . SMARTY_SYSPLUGINS_DIR) !== false) {
    $registeredAutoLoadFunctions = spl_autoload_functions();
    if (!isset($registeredAutoLoadFunctions['spl_autoload'])) {
        spl_autoload_register();
    }
} else {
    spl_autoload_register('smartyAutoload');
}

Which looked suspiciously culpable. So I added this line to my code:

spl_autoload_register('__autoload');

And then it worked!