PHP notice when adding RSS Widget

[solarissmoke]

When adding an RSS widget to a Widget Area that doesn't already have an RSS widget, you get the following PHP Notice:

PHP Notice: Undefined index: url in wp\wp-includes\default-widgets.php on line 750

Because $old_instance is an empty array.

I don't think the logic in the patch is proper.

Here's what it does: if the new instance has a URL, and it is different from the old instance URL, then $testurl should be true.

But what the new logic does, is force the old instance URL to also exist, thus making test URL false in the instance where a notice would be triggered.

The proper logic would probably be:

$testurl = ( isset($new_instance['url']) && ( ! isset($old_instance['url']) || ($new_instance['url'] != $old_instance['url']) ) )

Replying to nacin:

I don't think the logic in the patch is proper.

You're right, it doesn't work correctly. I've updated the patch as per your suggestion.

Fix PHP notice when adding new RSS widget

#16761

Incorporated into the patch on #16761.