Magento Magento 1 Update - How to Rico Neitzel told me back in the days, that during Magento updates files gets deleted, therefore it is a bad idea, therefore you want to run a patch (not the ones from Magento,
git Review Magento Updates This blogpost is of the kind: I don't want to forget that this exists, therefore I hope it helps you, but it's mine. :o) Magento updates are pain, because of the damn fcking