PHP 7.4 Notice warning for accessing a Array Offset when Array is null

[A-Matt]

Accessing a Page Edit screen returns the following between the Name & the URL, however this issue likely can be caused in more places where the get_var function does not return a row. Notice: Trying to access array offset on value of type null in <dir>\html\wp-includes\wp-db.php on line 2612 (Please note the line maybe slightly off due to a minor edit within our config)

	if(false === $result)
		return null;

	$row = sqlsrv_fetch_array( $result );
	return $row[ 0 ];   // <---- This line
}

"SELECT TOP 1 post_name FROM wp_posts WHERE post_name = '<POSTNAME>' AND post_type IN ( 'page', 'attachment' ) AND ID != 5227 AND post_parent = 4882" is the Failing SQL Query in my case. This is likely to no rows returned and can be fixed by changing it to:

Fix

return sqlsrv_has_rows( $result ) ? $row[ 0 ] : null;

or however else you'd prefer.

Currently at work so can make a basic PR Request later fixing this issue.

Edit: Information

SQLSRV: 5.9.0+14116 PHP: 7.4.15 (NTS) Nami: 5.7.2 (recent update from 5.3.2)

[patrickebates]

I've been unable to duplicate this on other PN sites running on PHP 7.4. Any thoughts on that?

[xadammr]

I can reproduce this on SQL Server 15.0.4138.2 / PHP 8.0.9 / Nami 2.8.0 / WP 5.8.

This is on a fresh install of Wordpress, with fresh database and only one post.

@A-Matt's fix works for me.

[A-Matt]

Since introducing this fix we've not had an issues in our System. The fix is likely due to some where in the code it's not correctly setup and is returning a null value somewhere where it shouldn't. The issue can also happen within Plugins ETC where they maybe looking for a specific thing and will get this error.

The query looks to be done at this point here: https://github.com/ProjectNami/projectnami/blob/4701ad96ac2f5d62155ee7ac6e93fd29ea436532/wp-includes/post.php#L4810-L4815