Correctly cache Contao translations that only exist as Symfony translations

[fritzmg]

Fixes #6741

[ausi]

Do we also need to create an empty cache file so that we do not search for language files here?

contao/core-bundle/contao/library/Contao/System.php

Lines 474 to 480 in 4034b23

	// Try to load from cache
	if (file_exists($strCacheDir . '/contao/languages/' . $strCreateLang . '/' . $strName . '.php'))
	{
	include $strCacheDir . '/contao/languages/' . $strCreateLang . '/' . $strName . '.php';
	}
	else
	{

[fritzmg]

True. I think we can change the logic of the ContaoCacheWarmer a bit in general. We already retrieve the catalogue for a locale in the lines above and I think we can set the $processed state to true there instead.

[fritzmg]

The addition of

if (!str_starts_with($domain, 'contao_')) {
    continue;
}

is actually another bugfix. There was no check previously and thus bogus Contao language cache files were created.

[aschempp]

Manually tested this in my project, seems to do the job 👍

[leofeyer]

Thank you @fritzmg.