post-template.php calls in_array() without checking args

[gcrumb]

Line 1039 of wp-includes/post-template looks like:

if ( in_array( $page->ID, $_current_page->ancestors ) )

... but in some circumstances, $_current_page->ancestors is null, which results in an error being thrown. I suggest testing the variable before passing it:

if ( gettype($_current_page->ancestors) === 'array' && in_array( $page->ID, $_current_page->ancestors ) )

[kovshenin]

Hey there!

in some circumstances, $_current_page->ancestors is null

Can you elaborate on that? Under what circumstances will ancestors be null? Also, you can use is_array rather than gettype. Thanks!

[SergeyBiryukov]

Related: #10381, #16574, #21309

[johnbillion]

I believe this was fixed in r23213.

[SergeyBiryukov]

Duplicate of #22882.