TYPO3 Core

We are slowly moving our projects from LTS 4.5 to LTS 6.2 and one of the issues we recently encountered is the usage of the configuration manager's (\TYPO3\CMS\Core\Configuration\ConfigurationManager) setters (setLocalConfigurationValueByPath & setLocalConfigurationValuesByPathValuePairs). Based on the "What's new" documentation for TYPO3 6.0 (http://typo3.org/download/release-notes/whats-new/) I was under the impression that using the configuration manager's getter/setters was the "new" way to do things. However, any attempt to use these methods quickly runs into

( ! ) Catchable fatal error: Argument 1 passed to TYPO3\CMS\Core\Utility\ArrayUtility::setValueByPath() must be an array

It turns out that the setter's failure to implement any kind of locking introduces a race condition which apparently cannot be fixed (@see Markus Klein's comment https://forge.typo3.org/issues/60294#note-13).

This all begs the question, why this method is available at all. What is the purpose of providing (and documenting) an API method which introduces a known issue and makes the system unstable?