Handle bad interval for cron schedule

[westonruter]

Trac ticket: https://core.trac.wordpress.org/ticket/64404

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Props westonruter, peterwilsoncc, johnbillion.

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[westonruter]

Maybe the $recurrence should be included here as well?

[peterwilsoncc]

I think this would be good if a named schedule is used, ie if the code doesn't fall back to

wordpress-develop/src/wp-includes/cron.php

Lines 361 to 368 in 8b0250c

	// Now we try to get it from the saved interval in case the schedule disappears.
	if ( 0 === $interval ) {
	$scheduled_event = wp_get_scheduled_event( $hook, $args, $timestamp );
	if ( $scheduled_event && isset( $scheduled_event->interval ) ) {
	$interval = $scheduled_event->interval;
	}
	}

[westonruter]

Not like 063c21e?

[peterwilsoncc]

I've added a few notes inline.

[peterwilsoncc]

Suggested change

	if ( ! is_int( $interval ) || $interval <= 0 ) {
	if ( ! is_numeric( $interval ) || $interval <= 0 ) {

Matches the behaivour of the existing check in wp_schedule_event()

[peterwilsoncc]

I think this would be good if a named schedule is used, ie if the code doesn't fall back to

wordpress-develop/src/wp-includes/cron.php

Lines 361 to 368 in 8b0250c

	// Now we try to get it from the saved interval in case the schedule disappears.
	if ( 0 === $interval ) {
	$scheduled_event = wp_get_scheduled_event( $hook, $args, $timestamp );
	if ( $scheduled_event && isset( $scheduled_event->interval ) ) {
	$interval = $scheduled_event->interval;
	}
	}

[johnbillion]

There's a failing test:

1) Tests_Cron::test_invalid_recurrence_for_event_returns_error
sprintf(): Argument number must be greater than zero

/var/www/src/wp-includes/cron.php:428
/var/www/tests/phpunit/tests/cron.php:856
phpvfscomposer:///var/www/vendor/phpunit/phpunit/phpunit:106
/var/www/vendor/bin/phpunit:118

[johnbillion]

It took me a couple of reads to understand what this is trying to tell me. The interval is an internal implementation detail that's not used by anyone calling this function, so I'm not sure it's an actionable message.

Is it possible to reliably distinguish between a schedule that doesn't exist and a schedule that exists but has an invalid interval? If so, let's use two separate error messages, one for each case, then make each error message clearer.

[westonruter]

How about c6efb67?