Multiple WP_CACHE definitions in wp-config.php

[eurobank]

Removing my old caching plugin, a

define('WP_CACHE', FALSE);

was left in wp-config.php. ZenCache added

define('WP_CACHE', TRUE);

at the top but didn't removed the FALSE, so i have two of this in my config. And apparently the FALSE is active (not sure).

Thanks

[raamdev]

@eurobank Thank you for the report! I have confirmed this bug.

When wp-config.php already contains a WP_CACHE definition, ZenCache is not properly removing/updating the existing value.

I have noticed that several other caching plugins, such as WP Super Cache, do not clean up after themselves when they are deactivated and deleted. They will leave behind the WP_CACHE definition inside wp-config.php instead of cleaning it up as they should (as ZenCache does when it is uninstalled).

[jaswrks]

@raamdev writes...

When wp-config.php already contains a WP_CACHE definition, ZenCache is not properly removing/updating the existing value.

That's definitely a bug, because this should happen; i.e., the intention is that we remove it before we add it back in, and fail if that is not possible.

Referencing: https://github.com/websharks/zencache/blob/150605-RC/src/includes/closures/Plugin/InstallUtils.php#L132

If you see this again, try to grab the raw file contents from the /wp-config.php file so we can analyze further, because there must be something slightly different about it for ZenCache not to pick it up; i.e., our regex pattern might need improvement.

[raamdev]

@jaswsinc Here you go:

<?php
define('WP_CACHE', TRUE);
/**
 * The base configurations of the WordPress.
 *
 * This file has the following configurations: MySQL settings, Table Prefix,
 * Secret Keys, and ABSPATH. You can find more information by visiting
 * {@link http://codex.wordpress.org/Editing_wp-config.php Editing wp-config.php}
 * Codex page. You can get the MySQL settings from your web host.
 *
 * This file is used by the wp-config.php creation script during the
 * installation. You don't have to use the web site, you can just copy this file
 * to "wp-config.php" and fill in the values.
 *
 * @package WordPress
 */

// ** MySQL settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define('WP_CACHE', false); //Added by WP-Cache Manager
define( 'WPCACHEHOME', '/Users/raam/Sites/zcpro.dev/wordpress/wp-content/plugins/wp-super-cache/' ); //Added by WP-Cache Manager
define('DB_NAME', 'zcdevpro');

Maybe it's the //Added by WP-Cache Manager on the same line that's messing up the regex? Or false being lowercase?

[jaswrks]

Thanks! :-)

So I verified the problem is not:

• A caSe problem with false.
• A problem with the //Added by WP-Cache Manager comment.
• A problem with the regex pattern itself.

It seems this bug is a bigger problem than I thought. It is related to this line:
https://github.com/websharks/zencache/blob/150605-RC/src/includes/closures/Plugin/InstallUtils.php#L174

The assumption is that an existing FALSE value for WP_CACHE is acceptable, because this method was originally written to disable WP_CACHE instead of removing it entirely; i.e., if an existing define('WP_CACHE', FALSE) is found, that's OK as far as this method is concerned, because it is disabled when that's the case.

However, it's NOT OK if we do in fact want to strip away all existing values for WP_CACHE before adding a new one. That's what addWpCacheToWpConfig() needs whenever it calls removeWpCacheFromWpConfig() before adding it back in.

I just looked through the rest of the codebase, and that's what all calls to this method want now too, so far as I can see. So I think the logic used by this method needs to change in order to resolve this.

Possible Resolution

• Remove these lines from the removeWpCacheFromWpConfig() method.

[eurobank]

This may sound naive but why remove the FALSE and not just change it to TRUE, not even changing the place in wp-config.php ...

[raamdev]

Next Lite Release changelog:

• Bug Fix: Fixed a bug where, in some rare cases, wp-config.php would end up with two WP_CACHE definitions. See Issue #509.

[raamdev]

Next Pro Release changelog:

• Bug Fix: Fixed a bug where, in some rare cases, wp-config.php would end up with two WP_CACHE definitions. See Issue #509.