(dev/core#1846) Ensure that the Container is always fresh when upgrading

[totten]

Overview

CiviCRM has a "container cache" (CachedCiviContainer.XXX.php) to organize the loading of various resources.

Generally, the "container cache" should auto-update whenever the corresponding CiviCRM code changes. However, there still appear to be some scenarios where it doesn't - which can lead to failures. For example, this comment reported an upgrade failure involving the resource ContactSchemaMapSubscriber -- that was removed in 5.27. The failure message implies that a stale copy of CachedCiviContainer.XXX.php retained a reference to ContactSchemaMapSubscriber.

Error: Class 'Civi\Api4\Event\Subscriber\ContactSchemaMapSubscriber' not found in
CachedCiviContainer->getCiviApi4EventSubscriberContactschemamapsubscriberService()
(line 426 of /home/webadmin/public_html/XXX/sites/default/files/civicrm/templates_/
CachedCiviContainer.XXX3a1bd2c1b046653ce2f7b8bfb2a5.php).

Before

When upgrading, the CachedCiviContainer.XXX.php performs its regular freshness check. This ordinarily causes it to refresh CachedCiviContainer.XXX.php. However, if (for any reason), the freshness check doesn't work - then it may complain.

After

When upgrading, the cache filename CachedCiviContainer.XXX.php changes (ie by choosing a different value of XXX). It will not read the old file - and it will only create a new/fresh file that matches the current version.

Comments

I could not reproduce the reported error organically with an upgrade from 5.26 to 5.27. To reproduce it, I had to use this procedure:

• Install v5.26
• Edit civicrm.settings.php to set define('CIVICRM_CONTAINER_CACHE', 'always');
• Switch to v5.27

In theory, the error might also happen if you upgrade from an older/buggier version - for example, in v5.24, it had a bug which put incomplete metadata into CachedCiviContainer.XXX.php. The bug in v5.24 could prevent it from rebuilding the file automatically on v5.27.

With the change in this patch, someone performing an upgrade should get a clean CachedCiviContainer even if the settings are weird (CIVICRM_CONTAINER_CACHE) and even if the previously-installed version had a bug.

[civibot]

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