Clear hasDataChanges flag after loading collection items

[elidrissidev]

Description (*)

PR created as a replacement for #2042 (comment)

When any collection is loaded, all its items have the hasDataChanges flag set to true because of the call to setData(). This causes unnecessary saves for unchanged items.

I also added a getter method to the status history model to prevent the setter from marking the model as dirty again, similar to what was done in #2066.

Related Pull Requests

• See Fixed PR #523, prevent unnecessary saving of status history when orde… #2042
• See Reduce unnecessary History updates on order saving. #523

Manual testing scenarios (*)

1. Load any collection and call hasDataChanges() on the items, it should be false.
2. Load status history collection from Order and call hasDataChanges() on the items, it should return false.

$order = Mage::getModel('sales/order')->load(123);
foreach ($order->getStatusHistoryCollection() as $history) {
    var_dump($history->hasDataChanges()); // bool(false)
}

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All automated tests passed successfully (all builds are green)
• Add yourself to contributors list

[kiatng]

Tested.

[fballiano]

cherrypicked to v20