drak/symfony — comment on commit 7390a1e0dc7f0f1135f809ef76bccafad701e329
File: src/Symfony/Component/HttpFoundation/FlashBag.php line 59
By lsmith77:

ok .. checked for similar places.
so when we have a one level array like the following we initialize for obvious reasons:
$array[] = 'foo';

However in the case as above where we have a subelement we indeed do not seem to initialize the subelements:
https://github.com/symfony/symfony/blob/master/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/AddCacheWarmerPass.php#L37
https://github.com/symfony/symfony/blob/master/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/FormPass.php#L40