Fixed undefined array index label_use_default in Mage_Catalog_Model_Product_Attribute_Backend_Media

[fballiano]

Fixes #4023

There could be other ways to fix this problem but I would initialize those 2 array elements

[kiatng]

Why not use empty() to check:

// from
$data['label']    = ($image['label'] === null || $image["label_use_default"]) ? null : $image['label'];
// to
$data['label']    = ($image['label'] === null || empty($image["label_use_default"])) ? null : $image['label'];

[fballiano]

@kiatng if i'm not mistaken that wouldn't cover the "store id = 0" situation and, when the conditions are in || but not all positive they automatically become hard to read to me :-)

[kiatng]

@fballiano You are right. I got confused with if ($storeId === 0) $image["label_use_default"] = false;. We want store 0 to have the default label, but in order to make sure of that, $image["label_use_default"] needs to be set to false, regardless of its prior value. It's counter intuitive.

when the conditions are in || but not all positive

It's hard as hell for me too.