Notice on class-wp-walker.php

[rodrigosprimo]

When using the Walker class I get the following notice:

Notice: Undefined offset: 0 in wp-includes/class-wp-walker.php on line 126

//display this element
if ( is_array( $args[0] ) )
    $args[0]['has_children'] = ! empty( $children_elements[$element->$id_field] );

If I'm not mistaken, this problem is happening because the code assumes that the $args variable is always a non empty array which is not the case.

I'm attaching the code I used to reproduce the problem and a patch to fix it.

[rodrigosprimo]

Patch

[rodrigosprimo]

Code used to reproduce the bug

[rmccue]

Looks good to me.

[SergeyBiryukov]

Introduced in [9830].

[nacin]

Looks good, yes.

[SergeyBiryukov]

In 23346:

Make sure the array exists before adding an element to it. props rodrigosprimo. fixes #23272.