Warning: Undefined array key 0 in /app/news/wp-includes/wp-db.php on line 1323

[mjaschen]

When using $wpdb->prepare() without passing values to ...$args (i.e. preparing a query without bound values), a warning is issued by PHP >= 8.0:

Warning: Undefined array key 0 in /app/news/wp-includes/wp-db.php on line 1323

Reason: it's assumed that at least one value is bound to the query by passing method arguments besides the query string which is not necessarily the case.

The fix: just check if the array contains a value at index 0 before using it.

[mjaschen]

Patch

https://core.trac.wordpress.org/ticket/54453

Trac ticket:

[SergeyBiryukov]

Hi there, welcome to WordPress Trac!

Thanks for the ticket and the PR, this looks good to me.

[SergeyBiryukov]

In 52206:

Database: Check if the $args[0] value exists in wpdb::prepare() before accessing it.

This avoids an Undefined array key 0 PHP warning if no values are passed to the method besides the query string.

Follow-up to [41470].

Props mjaschen.
Fixes #54453.