rewrite->flush() needlessly deletes the rewrite_rules option

[Denis-de-Bernardy]

All sorts of cache-related plugins hook into the update_option_rewrite_rules and force-flush whatever they're caching when rewrite_rules are updated.

When a page is saved, WP_Rewrite::flush() mindlessly deletes the rewrite_rule option, triggering all sorts of cache flushing that may or may not be necessary.

The attached patch keeps the rewrite_rules option intact when a soft refresh occurs.

Tests done:

• non-verbose rules used, page changes parent: no refresh
• verbose rules used, page changes parent: refresh

Dunno what else needs to be testing...

[rmccue]

Patch still applies cleanly.

[SergeyBiryukov]

Related: #27276, #29107.

[brokenflipside]

Refreshed

[brokenflipside]

I have refreshed the patch but can't determine how to test it properly. :(

[DrewAPicture]

Hi @brokenflipside, thanks for the refresh! Let's also add a changelog entry to the DocBlock for the new parameter while we're at it. More on changelogs in the ​core contributor handbook.

Replying to brokenflipside:

I have refreshed the patch but can't determine how to test it properly. :(

A good place to start would be phpunit/tests/rewrite.php. I'd suggest taking a look at how some of the other methods are being tested.

For example, start by declaring the $wp_rewrite global in order to access running the method, then perhaps test the existence of the option before and after the method is run.

[SergeyBiryukov]

#29107 has a related patch, should we perhaps merge them?

[swissspidy]

Replying to SergeyBiryukov:

#29107 has a related patch, should we perhaps merge them?

I updated the patch there. Does this perhaps already fix this ticket because the option is only ever updated and not deleted?

[swissspidy]

After [36254] I'll consider this a duplicate of #29107, as the option now never gets deleted.

Feel free to reopen if I'm wrong.