Deleting Bundled Product Items from a Quote

Here’s another caution sign if you’re using the sales/quote object’s deleteItem or removeItem method. If you look at the code that marks an item for deletion

$item->isDeleted(true);
if ($item->getHasChildren()) {
    foreach ($item->getChildren() as $child) {
        $child->isDeleted(true);
    }
}

$parent = $item->getParentItem();
if ($parent) {
    $parent->isDeleted(true);
}

In addition to removing the item you asked about, Magento will remove any child items (members of a bundled product) or any parent items (the bundled parent if you remove a specific child item of the bundled product). Likely the right behavior (although I could argue for an exception being thrown if you try to remove a child item), but one that leads to confusing results if you’re foreaching over a quotes items collection and removing items based on criteria.