Cron: Add no cache headers before calling `fastcgi_finish_request()`

[peterwilsoncc]

Calls to wp-cron.php are not intended to be cached.

In the block checking for and running fastcgi_finish_request() adding headers to prevent caching will prevent the DefaultTTL from being used on CDNs such as CloudFlare.

Expires: Wed, 11 Jan 1984 05:00:00 GMT
Cache-Control: no-cache, must-revalidate, max-age=0

[kingkero]

added Cache-Control and Pragma header

[peterwilsoncc]

@kingkero Thanks so much for the patch.

You've put the headers in the perfect spot, but it is OK if you use the Expires and Cache-Control headers I noted above?

WordPress has a function nocache_headers() that uses the expires and cache-control headers. nocache_headers() isn't available here but using the same two headers will ensure consistency for WordPress sites.

I've marked this patch as needing a refresh, if you have time that would be great but I (or another person) can pick it up if you don't.

[kingkero]

@peterwilsoncc You're very welcome.

I added a new diff with the headers from the wp_get_nocache_headers() method and removed the Pragma, since the other method doesn't set it either

[peterwilsoncc]

CS Fixes rquired by wp-cron.php prior to fixing #47396

[peterwilsoncc]

In 45559:

Code is Poetry: CS Fixes required in wp-cron.php.

See #47396, #41057.

[peterwilsoncc]

Closed in 45560 but yours truly made a typo and left the hash of the ticket number. @kingkero your props will still be recorded once 5.3 is released.

In 45560:

(The changeset message doesn't reference this ticket)

[johnbillion]

#25072 was marked as a duplicate.