While this PR addresses the warning issue, it will hide the potential logical error. Think about the following case :

• User has core.edit.own permission but does not have core.edit permission.
• The current list of contacts does not have any contact belongs to him

With the proposed code, the Edit column will still being displayed but there is no contact items in the table editable, and it is not right. We could use the code like below handle it:

$showEditColumn = false;

if ($canEdit) {
    $showEditColumn = true;
} elseif ($canDo->get('core.edit.own') && !empty($this->items)) {
    foreach ($this->items as $item) {
        if ($item->created_by == $userId) {
            $showEditColumn = true;
            break;
        }
    }
}

After that blog of code, $showEditColumn will determine if we should show edit column. I would even go further by adding $showEditColumn as a property of view class and move that logical calculation to the view to avoid too much logic handle inside the layout.

Tried to add $showEditColumn to the view class but couldn't get it to work (not very familiar with Joomla code)
It doesn't really save much since the layout has to calculate for each row anyway, using the same logic.

I have tested this item ✅ successfully on 2da47f2

I have tested this item ✅ successfully on 2da47f2

RTC. The current change is fine as it is. Further improvement if required could be done in separate PR.

Thank you